Journal articles on the topic 'High-vacuum plume test facility'
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Neumann, Andreas. "STG-ET: DLR Electric Propulsion Test Facility." Journal of large-scale research facilities JLSRF 4 (November 5, 2018): 134. http://dx.doi.org/10.17815/jlsrf-3-156-1.
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Abstract: DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET). This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target made of low sputtering material, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.
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Neumann, Andreas, and Nina Sarah Mühlich. "Ground-Based Experiment for Electric Propulsion Thruster Plume—Magnetic Field Interaction." Aerospace 10, no. 2 (January 26, 2023): 117. http://dx.doi.org/10.3390/aerospace10020117.
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Electric space propulsion is a technology which is employed on a continuously increasing number of spacecrafts. While the current focus of their application area is on telecommunication satellites and on space exploration missions, several new ideas are now discussed that go even further and apply the thruster plume particle flow for transferring momentum to targets such as space debris objects or even asteroids. In these potential scenarios, the thruster beam impacts on distant objects and subsequently generates changes in their flight path. One aspect which so far has not been systematically investigated is the interaction of the charged particles in the propulsion beam with magnetic fields which are present in space. This interaction may result in a deflection of the particle flow and consequently affect the aiming strategy. In the present article, basic considerations related to the interaction between electric propulsion thruster plumes and magnetic fields are presented. Experiments with respect to these questions were conducted in the high-vacuum plume test facility for electric thrusters (STG-ET) of the German Aerospace Center in Göttingen utilizing a gridded ion thruster, an RIT10/37, and a Helmholtz coil to generate magnetic fields of varying field strength. It was possible to detect a beam deflection on the RIT ion beam caused by a magnetic field with an Earth-like magnetic field strength.
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Farahani, M., N. Fouladi, and AR Mirbabaei. "Design and analysis of a cooling system for a supersonic exhaust diffuser." Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 233, no. 14 (April 2019): 5253–63. http://dx.doi.org/10.1177/0954410019840970.
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High-altitude test facilities are usually used to evaluate the performance of space mission engines. The supersonic exhaust diffuser, a main part of high-altitude test facility, provides the required test cell vacuum conditions by self-pumping the nozzle exhaust gases to the atmosphere. However, the plume temperature is often much higher than the temperature the diffuser structure is able to withstand, usually above 2500 K. In this study, an efficient cooling system is designed and analyzed to resolve the thermal problem. A water spray cooling technique is preferred among various existing techniques. Here, a new algorithm is developed for a spray cooling system for a supersonic exhaust diffuser. This algorithm uses a series of experimental and geometrical relationships to resize the governing parameters and remove the required heat flux from the diffuser surface. The efficiency of the newly designed cooling system is evaluated via numerical simulations. The utilized numerical technique is based on the discrete-phase method. Various computational studies are accomplished to enhance the accuracy of numerical prediction and validation. The present numerical study is validated using experimental results. The results show that the realizable k-ɛ method is superior compared to other Reynolds-averaged Navier–Stokes models.
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Chai, Kil-Byoung, Duck-Hee Kwon, and Minkyu Lee. "Development of plasma beam irradiation facility using applied-field MPD thruster to study plasma-surface interactions." Plasma Physics and Controlled Fusion 63, no. 12 (November 10, 2021): 125020. http://dx.doi.org/10.1088/1361-6587/ac2eb1.
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Abstract A plasma beam irradiation facility was developed based on the applied-field magnetoplasmadynamic (AF-MPD) thruster concept for studying plasma-surface interactions. The AF-MPD thruster was chosen because it can produce a plasma beam with high plasma density in continuous-wave mode. Two types of AF-MPD thruster were developed and used in this study: a type I source with a wide thruster channel was used for a heat flux test with Ar or Xe gas, while a type II source with a narrow thruster channel was used for an ion flux test with H2 or He gas. The plasma initially showed the characteristics of abnormal glow discharges and then a transition to arc occurred when the plasma current exceeded a threshold value. It was found that a cathode made of thoriated tungsten significantly lowered the threshold current for the transition from abnormal glow to arc. The maximum heat flux provided by our facility was measured to be 7 MW m−2 using a custom-made heat flux sensor, while the maximum hydrogen ion flux was measured to be 1 × 1023 m−2 s−1 using a Langmuir probe. The electron temperature ranged between (4–5) eV, while the electron density at the plasma plume (downstream) ranged between (1–4) × 1018 m−3.
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Allen, John, and Brian Walsh. "ENHANCED OIL SPILL SURVEILLANCE, DETECTION AND MONITORING THROUGH THE APPLIED TECHNOLOGY OF UNMANNED AIR SYSTEMS." International Oil Spill Conference Proceedings 2008, no. 1 (May 1, 2008): 113–20. http://dx.doi.org/10.7901/2169-3358-2008-1-113.
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ABSTRACT Many leading edge technologies that are conceptualized, developed, tested, refined and applied as military defense technologies evolve into useful applied technologies in other public and private sectors. Unmanned Air Systems (UAS) and the rapidly evolving Small Unmanned Air Vehicle (SUAS) are finding operational applications in scientific research, wildlife, law enforcement, security, natural disaster, and environmental surveillance, detection and monitoring. This paper will review the use of UAS in operational oil spill surveillance, monitoring and assessment. UAS show particular potential for shoreline, coastal and inland surveillance and monitoring of remote areas with limited accessibility. Numerous international oil companies have sponsored UAV demonstrations focused on facility and pipeline inspection, surveillance and monitoring. Governmental agencies, including the U.S. Coast Guard and National Oceanic and Atmospheric Agency, have incorporated UAS into oil spill response exercises and test applications. Currently, many areas of high risk to pollution and high environmental sensitivity are monitored daily by costly manned aircraft surveillance; UAS can replace or augment these manned air vehicles, providing a cost effective alternative that also reduces human risks. UAS technology is continually evolving to achieve broader application:On-water launch and in-water recovery;Payload Integration - video, still daylight and nighttime IR imaging, image processing, and hazardous material air plume sensing and mapping;Command, Control and Communications (C-3) - real-time data link to the Incident Command Post;Platform Improvements - greater reliability, minimized size and weight, portability, longer operational flight time and extended range, and improved power sources;GPS positioning - pre-programmed flight patterns and break-away vectoring; andSimulation & Training - train effectively, maintain proficiency, and evolve tactics, techniques and procedures.
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Jelínek, Tomáš, Erik Flídr, Martin Němec, and Jan Šimák. "Test Facility for High-Speed Probe Calibration." EPJ Web of Conferences 213 (2019): 02033. http://dx.doi.org/10.1051/epjconf/201921302033.
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A new test facility was built up as a part of a closed-loop transonic wind tunnel in VZLU´s High-speed Aerodynamics Department. The wind tunnel is driven by a twelve stage radial compressor and Mach and Reynolds numbers can be changed by the compressor speed and by the total pressure in the wind tunnel loop by a set of vacuum pumps, respectively. The facility consists of an axisymmetric subsonic nozzle with an exit diameter de = 100 mm. The subsonic nozzle is designed for regimes up to M = 1 at the nozzle outlet. At the nozzle inlet there is a set of a honeycomb and screens to ensure the flow stream laminar at the outlet of the nozzle. The subsonic nozzle can be supplemented with a transonic slotted nozzle or a supersonic rigid nozzle for transonic and supersonic outlet Mach numbers. The probe is fixed in a probe manipulator situated downstream of the nozzle and it ensures a set of two perpendicular angles in a wide range (±90°). The outlet flow field was measured through in several axial distances downstream the subsonic nozzle outlet. The total pressure and static pressure was measured in the centreline and the total pressure distribution in the vertical and horizontal plane was measured as well. Total pressure fluctuations in the nozzle centreline were detected by a FRAP probe. From the initial flow measurement in a wide range of Mach numbers the best location for probe calibration was chosen. The flow field was found to be suitable for probe calibration.
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Swamy Kidambi, Rajamannar, Prakash Mokaria, Samir Khirwadkar, Sunil Belsare, M. S. Khan, Tushar Patel, and Deepu S. Krishnan. "Design and performance of vacuum system for high heat flux test facility." Journal of Physics: Conference Series 823 (April 19, 2017): 012024. http://dx.doi.org/10.1088/1742-6596/823/1/012024.
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Prashana ANL, Kavin, Aldin Justin Sundararaj, and Mukit Azad Khan. "Investigation of nozzle flow in high altitude test facility." Advances in Mechanical Engineering 14, no. 5 (May 2022): 168781402110477. http://dx.doi.org/10.1177/16878140211047724.
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A high altitude test facility was developed for the experimental studies on nozzles for various levels of vacuum. The current study is focused on the performance of the nozzle under various altitude condition and to characterized the high altitude test facility. A supersonic nozzle designed for Mach 2.5 is used for the study. Compressed air is taped from the high pressure plenum having a pressure of 20 bar and is regulated and expanded through the nozzle. The inlet pressures for the study is varied from 4.5 to 10 bar. The nozzle is within the enclosure which is evacuated to 0.7–0.02 bar. Schlieren is used to view the flow condition at the end of the nozzle. A nozzle for 2.5 Mach is designed and tested in HAT facility. The nozzle design is validated with the CFD for various NPR. The high altitude test facility is characterized for various NPR and is found to be optimum flow at 14 NPR for 33 s at an inlet pressure of 4.5.
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Lian, Xue, Nan Hua, Liu Jiaqi, Liu Xin, and Meng Gang. "The Design of Large Arc-shape High-precision Walking Device in TV (thermal-vacuum) Conditions." MATEC Web of Conferences 237 (2018): 03014. http://dx.doi.org/10.1051/matecconf/201823703014.
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The large-sized space environmental simulation test facility is mainly used for providing thermal radiation environment in high-vacuum, cold and dark space for satellites, spacecraft, lunar spacecraft to carry out whole satellite thermal vacuum test and for large equipment like antenna to carry out tests in TV conditions. Monitoring the spacecraft’s surface optical image or temperature is a main task in space environment simulation test. In previous tests, optical image test mainly took place in a fixed position, so the measuring location and angle are limited. This paper focuses on large spherical space environmental simulation test facility, and designs a large arc-shape high-precision walking device in a space environment simulation test device. It introduces key technology in detail like structure design, thermal design, processes and manufacturing, etc. The test results show that this device can work steadily and reliably under simulation space environments, and the precision exceeds 0.5°.
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Milam, Laura. "Test Facility Requirements for the Thermal Vacuum Thermal Balance Test of the Cosmic Background Explorer Observatory." Journal of the IEST 34, no. 2 (March 1, 1991): 27–33. http://dx.doi.org/10.17764/jiet.2.34.2.b12g343q753w0105.
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The cosmic background explorer observatory (COBE) underwent a thermal vacuum/thermal balance (TV/TB) test in the space environment simulator (SES) at the Space Simulation Test Laboratory, Goddard Space Flight Center. This was the largest and most complex test ever accomplished at this facility. The 4 × 4 m (13 × 13 ft) spacecraft weighed approximately 2223 kg (4900 lb) for the test. The test setup included simulator panels for the inboard solar array panels, simulator panels for the, flight cowlings, sun and earth sensor stimuli, thermal/radio frequency shield heater stimuli, and a cryopanel for thermal control in the attitude control system/shunt dissipator area. The fixturing also included a 4.3 m (14 ft) diameter gaseous helium cryopanel which provided a 20° Kelvin (K) (-253° C) environment for the calibration of one of the spacecraft's instruments, the differential microwave radiometer. This cryogenic panel caused extra contamination concerns so a special method was developed and written into the test procedure to prevent the high buildup of condensibles on the panel, which could have led to backstreaming of the thermal vacuum chamber. The test was completed successfully with a high-quality simulated space environment provided to the spacecraft. This paper describes the test requirements, test setup, special fixturing requirements, related contamination concerns, and a general discussion of the test and test results.
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Sun, Z., L. Huang, X. Shi, and XL Wang. "Conceptual design of DALS test facility cryogenic system." IOP Conference Series: Materials Science and Engineering 1240, no. 1 (May 1, 2022): 012086. http://dx.doi.org/10.1088/1757-899x/1240/1/012086.
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Abstract Dalian advanced light source (DALS) is a new project proposed by Dalian Institute of Chemical Physics (DICP) aiming to produce high-quality electron beam with repetition rate up to 100 kHz and the project is subject to central government approval. The cryomodules and superconducting cavities need to be tested before assembled in the real accelerator so the test facility is necessary. The Accelerator module test facility (AMTF) project has been funded by Dalian local government and is currently under construction as the pre-research project for DALS, it consists of four testbenches, one Horizontal testbench (HTB) for cryomodule test, one Vertical testbench (VTB) for cavity test, one Cryogenic testbench (CTB) for cryogenic test and one Injector testbench (ITB) for beam test. A Test facility cryoplant (TFCP) with capacity of 370 W@2 K will be used for cooling testbenches. This paper presents the design and current progress of the TFCP system, which includes the refrigerators, helium compressors, process vacuum pump system (PVPS), gas storage system, recovery and purification system.
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Weingartner, C. "Vacuum Baking of Shuttle/Centaur Components." Journal of the IEST 29, no. 2 (March 1, 1986): 46–48. http://dx.doi.org/10.17764/jiet.1.29.2.16680m874uxn1781.
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A variation of the Centaur launch vehicle will be used as a high-performance upper stage to launch spacecraft from the Space Shuttle cargo bay into geosynchronous orbit. As an element of the Shuttle payload, Centaur must be designed to avoid contaminating sensitive spacecraft surfaces. Nonmetallic materials used in structural and electronic applications can exhibit high rates of outgassing in a space vacuum and contaminate critical spacecraft surfaces of varying temperatures as condensation occurs. Judicious material selection, per NASA specifications, is used to control instances of such contamination. Vacuum baking is permitted by NASA Specification SP-R-0022 to "bake out" potential sources of organic contamination. Most Shuttle/Centaur missions are planned for spacecraft having surfaces of various temperatures in locations that are susceptible to condensation of organic outgassing products. To determine the extent of potential contamination, General Dynamics has initiated a test program with the White Sands Test Facility that is designed to measure outgassing and condensation rates of nonmetallic components in their use configuration. This paper reviews the tests, equipment requirements, sensor instrumentation, and some of the results to date.
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Cerimele, Mary, Jonathan Homan, Sam Garcia, Jaime Garza, Gabriel Hirsch, John Lauterbach, Robert Linza, and Gerardo Vargas. "Modernization of NASA Johnson Space Center’s Chamber A to support Cryogenic Vacuum Optical Testing of the James Webb Space Telescope (JWST)." Journal of the IEST 64, no. 1 (December 1, 2021): 30–41. http://dx.doi.org/10.17764/1557-2196-64.1.30.
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Abstract NASA is the mission lead for the James Webb Space Telescope (JWST), the next of the “Great Observatories,” scheduled for launch in 2021. NASA is directly responsible for the integration and test (I&T) program that culminated in an end-to-end cryo vacuum optical test of the flight telescope and instrument module in Chamber A at NASA Johnson Space Center. Historic Chamber A is the largest thermal vacuum chamber at Johnson Space Center and one of the largest space simulation chambers in the world. Chamber A has undergone a major modernization effort to support the deep cryogenic, vacuum and cleanliness requirements for testing the JWST. This paper describes the upgrades to the Chamber A facility: Thermal Shrouds, Helium Refrigeration, Liquid Nitrogen System, High Vacuum System, Clean Airflow System, and Utilities.
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Salich, V. L. "Development of the active gas generator for high altitude firing test benches." VESTNIK of Samara University. Aerospace and Mechanical Engineering 18, no. 1 (April 16, 2019): 118–27. http://dx.doi.org/10.18287/2541-7533-2019-18-1-118-127.
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The results of research on increasing the efficiency of a firing test facility for testing thrusters under high-altitude conditions are presented. The increase in efficiency consists in reducing the expansion pressure generated by the ejector and the flow of the active gas (air) consumed by it. Experimental studies were carried out using three versions of gas generators developed by the author which ensure an increase in the energy of the active gas before it is supplied to the ejector. When using the GG-1 gas generator with working media such as air, kerosene and water, the vacuum of less than 1 mm Hg was achieved with the air mass flow rate of 1.1 kg/s (the ejector provides a vacuum of 13 mm Hg with the cool air flow rate of 2 kg/s). However, the design features of the gas generator led to a cumbersome system of supplying working fluids and a complicated start-up sequence. The GG-2 gas generator with air and kerosene as working media failed to provide the temperature of the active gas below 600°C, therefore, to prevent ejector malfunctioning, GG-2 was turned off when the rarefaction reached 13 mm Hg. The air mass flow rate was 1.1 kg/s. The working media of the GG-3 gas generator are air and kerosene or air and natural gas. The design of the GG-3 makes it possible to regulate the temperature of the produced active gas. When working on kerosene, a vacuum of 4 mmHg was reached with the air mass flow rate of 1.5 kg/s. The studies of GG-3 using natural gas as a fuel are going on.
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Ke, Zun-Jian, Jia-Cai Li, Shao-Ping Zhang, Guang-Peng An, Xing-Hua Tang, and Tao Yang. "A plastic scintillating fiber position detector in vacuum for the test beam facility at BEPC II -LINAC." Chinese Physics C 36, no. 1 (January 2012): 67–70. http://dx.doi.org/10.1088/1674-1137/36/1/011.
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Liu, S., F. Bogard, P. Cornebise, A. Faus-Golfe, N. Fuster-Martínez, E. Griesmayer, H. Guler, et al. "In vacuum diamond sensor scanner for beam halo measurements in the beam line at the KEK Accelerator Test Facility." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 832 (October 2016): 231–42. http://dx.doi.org/10.1016/j.nima.2016.06.122.
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Guo, Feng, Bo Tao Liu, Xiao Han, Yan Qi, and Yi Zhang. "A Self-Alignment Sealing Hatch-Door System Updated for Airlock Chambers of KM6 Space Simulator." Applied Mechanics and Materials 390 (August 2013): 606–10. http://dx.doi.org/10.4028/www.scientific.net/amm.390.606.
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KM6 space simulator built in 1990s is currently the largest thermal vacuum test facility for spaceships and satellites in China. In order to meet new requirements of ground test for outer-cabin space walk of astronauts under China Manned Space Project II, a hatch-door system with ten rectangular doors in auxiliary horizontal chamber of KM6 space simulator has been updated since 2006. For the sake of pressure balance, every hatch-door is upgraded with a pressure regulator, which enables easy close and open of every hatch-door under no pressure difference. To improve vacuum compatibility of rotating hatch-doors, single axis hinge mechanism is renewed as biaxial hinge mechanism with more degrees of freedom for door spindle, which is combined with coordinated lock mechanism and O-ring sealing structure to realize the self-alignment sealing of hatch-door flange structure. Up until now, three manned spaceships of SZ-5, SZ-6 and SZ-7 have successfully finish thermal vacuum tests in auxiliary horizontal chamber with high performance of the updated hatch-door system as results.
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Dunwoody, Rachel, Jack Reilly, David Murphy, Maeve Doyle, Joseph Thompson, Gabriel Finneran, Lána Salmon, et al. "Thermal Vacuum Test Campaign of the EIRSAT-1 Engineering Qualification Model." Aerospace 9, no. 2 (February 12, 2022): 99. http://dx.doi.org/10.3390/aerospace9020099.
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CubeSats facilitate rapid development and deployment of missions for educational, technology demonstration, and scientific purposes. However, they are subject to a high failure rate, with a leading cause being the lack of system-level verification. The Educational Irish Research Satellite (EIRSAT-1) is a CubeSat mission under development in the European Space Agency’s (ESA) Fly Your Satellite! Programme. EIRSAT-1 is a 2U CubeSat with three novel payloads and a bespoke antenna deployment module, which all contribute to the complexity of the project. To increase the likelihood of mission success, a prototype model philosophy is being employed, where both an engineering qualification model (EQM) and a flight model of EIRSAT-1 are being built. Following the assembly of the EQM, the spacecraft underwent a successful full functional test and month-long mission test. An environmental test campaign in ESA Education Office’s CubeSat Support Facility was then conducted with the EQM where both vibration and thermal verification test campaigns were performed. The focus of this paper is the thermal testing and verification of the EIRSAT-1 EQM. Over three weeks, the EQM was subjected to one non-operational cycle, three and a half operational cycles, and a thermal balance test in a thermal vacuum chamber. After dwelling at each temperature extreme, functional tests were performed to investigate the performance of the spacecraft in this space representative environment. The approach to planning and executing the thermal testing is described in detail including the documentation required, set up of the test equipment, and determination of the test levels. Overall, the campaign demonstrated that the mission can successfully operate in a space environment similar to that expected in orbit, despite encountering a number of issues. These issues included a payload displaying anomalous behaviour at cold temperatures and needing to redefine test levels due to an insufficient understanding of the internal dissipation in the spacecraft. A total of two major and three minor non-conformances were raised. Crucially, these issues could not have been found without thermal testing, despite the comprehensive ambient tests performed. The main results and lessons learned during this thermal test campaign are presented with the aim of guiding future missions on optimal approaches in organising and executing the thermal testing of their CubeSats.
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Ye, Ko, Polina Pronina, and Pavel Polyakov. "Mathematical modelling of the effect of heat fluxes from external sources on the surface of spacecraft." Journal of Applied Engineering Science 18, no. 4 (2020): 732–36. http://dx.doi.org/10.5937/jaes0-28180.
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Modelling the extraneous heat exchange of spacecraft using solar radiation simulation facility and simulators of the planetary radiation field in several cases is an intractable problem not only in technical but also in methodological terms. For some technical reasons, solar radiation simulator is stationary. Consequently, to reproduce a possible change in the orientation of the test object relative to the solar radiation flux, it is necessary to equip the thermal vacuum unit with devices that allow the test object to be rotated at least about two axes. In this paper, a mathematical model and a method for solving the problem of heat transfer in a multilayer structure of screen-vacuum thermal insulation under the influence of solar radiation is proposed. A method is proposed for the numerical solution of a normal system of nonlinear differential equations using the linearisation of nonlinear terms. Various results of numerical modelling were obtained, which indicate the adequacy of the proposed mathematical model. It has been revealed that high-inertia thermal insulation of sufficient thickness is required to stabilise the thermal state inside the spacecraft.
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Poletskov, P. P., O. A. Nikitenko, M. V. Mishukov, A. S. Kuznetsova, and E. V. Lopatina. "Effect of vacuum smelting method on the quality of pipe steel of northern application." Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 76, no. 8 (September 3, 2020): 810–17. http://dx.doi.org/10.32339/0135-5910-2020-8-810-817.
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Pipe metal of Northern application must meet increased requirements of strength properties, low-temperature ductility, cold resistance and weldability. Cracks, skins, flaws, roll-ins and other defect are not allowed on the surface of pipes. The fulfillment of the requirements substantially can be provided by the process of steel smelting by a vacuum remelting method. Study of the effect of 03ХГ grade pipe steel smelting in vacuum and without vacuum on its contamination by nonmetallic inclusions and resistance against hydrogen cracking was accomplished. The smelting of ingots of adjusted chemical composition was carried out in a vacuum induction furnace ZG-0.06L. To imitate the process of hot roughing rolling, hydraulic press П6334 of 250 t force was used. Finishing rolling was carried out at reversible hot rolling mill 500 duo, combined with a controlled cooling facility. It was determined, that the samples, smelted in vacuum, had insignificant number of nonmetallic inclusions and withstand the test of resistance against hydrogen cracking; cracks were not detected on them. After testing on resistance against hydrogen cracking of the samples smelted without vacuum, cracks were discovered, located on both the surface and central layers amounting to 600 mm and 1700 mm length correspondently. It was shown, that steel smelting in vacuum allows to reach a high degree of the steel purity, results in increased crack growth resistance and in decreased number of nonmetallic inclusions in the pipe steel of Northern application.
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Shaharuddin, S., J. Stuchbery, E. C. Simpson, Z. K. Gan, A. C. Green, A. Cho, and E. Lu. "External beam for the Heavy Ion Accelerator Facility." EPJ Web of Conferences 232 (2020): 01005. http://dx.doi.org/10.1051/epjconf/202023201005.
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Radiotherapy using protons and heavier ions is emerging as an alternative to traditional photon radiotherapy for cancer treatment. Ions have a depth-dose profile that results in high energy deposition at the end of the particle’s path, with a relatively low dosage elsewhere. However, the specifics of ion interactions with cellular biology are not yet fully understood. To study the induced biological effects of the ions on cell cultures, an external beam is required as biological specimens cannot be placed in vacuum. The Heavy Ion Accelerator Facility (HIAF) at the Australian National University hosts accelerators for a wide variety of ion-beam research applications. However, HIAF does not currently have an external beam capability. Here, we present an initial design for a radiobiological research capability at HIAF. A systems engineering approach was used to develop the architecture of the apparatus and determine the feasibility of adapting the current facilities to external beam applications. This effort included ion optics calculations, coupled to a Geant4 simulation, to characterise ion beam transitions through a thin window into the air. The beam spread, intensity distributions, and energy of proton and carbon ions were studied as a function of distance travelled from the window, as well as the effects of alternative window materials and thicknesses. It was determined that the proposed line at the HIAF would be suitable for the desired applications. Overall, this feasibility study lays the foundations of an external beam design, a simulation test framework, and the basis for a grant application for an external beam at the HIAF.
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Kushoro, M. H., G. Croci, I. Mario, A. Muraro, D. Rigamonti, S. Cancelli, A. De Lorenzi, et al. "Characterization of vacuum HV microdischarges at HVPTF through X-ray bremsstrahlung spectroscopy." Journal of Instrumentation 17, no. 01 (January 1, 2022): C01054. http://dx.doi.org/10.1088/1748-0221/17/01/c01054.
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Abstract The development of MITICA, the prototype for a neutral beam injector for ITER, drives the interest in investigating high HV insulation in vacuum. The High Voltage Padova Test Facility (HVPTF) is an experimental device with the aim of studying the fundamental processes leading to discharges, offering a framework to develop new diagnostics, models, and mode of operations for MITICA. For this purpose, HVPTF features a vacuum chamber containing two electrodes which can achieve an HV difference up to 800 kV. X-ray bremsstrahlung radiation produced by free charges accelerated by the HV was proven to be a promising monitoring mechanism in the past; as such, two scintillating crystals, a LYSO and a LaBr3, coupled with fast electronics were used to conduct hard X-ray spectroscopy. This work describes a newly custom-developed software tool to analyze the spectroscopy from scintillators and integrate it with the HVPTF analog data. The tool was employed to study two experimental sessions, reaching promising results in the characterization of microdischarges, especially in terms of time resolution. Detection limits imposed by pile-up and other processes were identified and addressed, finding the best range of operation of the two scintillators. The performed study opens the way for the analysis of data obtained in all 2020 and 2021 experimental campaigns, thus giving the possibility to implement future improvements in HVPTF X-ray spectroscopy.
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Perin, J. P. "Cryogenic systems for LMJ cryotarget and HiPER application." Laser and Particle Beams 28, no. 1 (March 2010): 203–8. http://dx.doi.org/10.1017/s0263034610000091.
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AbstractFor the future, we have to develop new sources of energy. These new sources may be based on nuclear fusion with magnetic confinement (as with the ITER experiment) or with a new concept based on inertial confinement. The European community plans to build a facility (HiPER project) which is dedicated to reaching high gain with cryogenic targets, and to test the concepts of target mass production and rep rate shots. The cryogenic system for the 1stphase experiments in HiPER is based on the cryogenic system developed for the French facility Laser MegaJoule (LMJ). The latter must be modified and upgraded for direct drive targets. In particular the target must be protected from the radiation flux from the vacuum vessel by a thermal shroud. In addition, the LMJ system must be equipped with a thermal system to allow layering of the fusion fuel to take place. The new developments concern a leak tightness thermal shroud for direct drive and a fast shroud retractor able to allow the laser shot within few milliseconds.
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Jahnke, Doug, Salih Yildiz, and Yiannis Andreopoulos. "Embedding sensors in composite plates for characterization under impacting shock wave loading." Journal of Composite Materials 52, no. 27 (April 27, 2018): 3831–50. http://dx.doi.org/10.1177/0021998318770513.
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High-frequency-response, semiconductor, strain gages used in various combinations have been embedded in S-2 glass epoxy composite test plates during in-house fabrication using vacuum-assisted resin transfer molding in order to measure the transient strain and its rate during the impingement of the shock wave and subsequent interactions. To validate the techniques systematically, an in-house-developed, split-view time-resolved, stereo digital image correlation system has been used to compare static and time-dependent strain signals on a two-dimensional surface in a shock tube facility. Small size non-encapsulated solid-state gages were cumbersome to handle during the fabrication process, while encapsulated strain gages had very good spatial resolution and overall performance combined with some ease in handling during fabrication. The strain results indicate that embedding sensors is an accurate and inexpensive method to characterize composites under high-rate loading.
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Oh, Philyong, Hoseok Kim, Boram Kang, and Bong Guen Hong. "An Experimental Study on the Ablation Properties of Carbon/Carbon Composites Using Thermal Plasma." Science of Advanced Materials 12, no. 9 (September 1, 2020): 1271–77. http://dx.doi.org/10.1166/sam.2020.3793.
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The ablation properties of two carbon/carbon (C/C) composites currently considered as thermal protection materials for radioisotope thermoelectric generators (RTGs) were investigated using a plasma wind tunnel with a heat flux between the range of 2–4 MW/m2. The ablation properties were identified through an analysis of erosion rates and microstructures after testing. During ablation, erosion reactions of the matrix were faster than those of fibers and pores, and the defects and cracks between the fibers and matrix grew. The fibers eroded from their outer surface and ablation led to the formation of sharp tapered tips. Lower density C/C composites appeared to lose more matrix than higher density C/C composites. The erosion rate increased with heat flux. The ablation properties were compared with the test results using a vacuum plasma spray (VPS) facility and an E-beam facility. It was shown that both thermochemical and thermomechanical erosion occurred via oxygen in the plasma flow, and a rapid high-pressure heat stream occurred in tests using the plasma wind tunnel while only thermal ablation occurred in tests using the VPS and E-beam facilities.
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Boafo, Fred Edmond, Jin-Hee Kim, Jong-Gwon Ahn, Sang-Myung Kim, and Jun-Tae Kim. "In Situ Experimental Investigation of Slim Curtain Wall Spandrel Integrated with Vacuum Insulation Panel." Buildings 12, no. 2 (February 9, 2022): 199. http://dx.doi.org/10.3390/buildings12020199.
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Almost every major city’s skyline is known for high-rise iconic buildings with some level of curtain wall system (CWS) installed. Although complex, a CWS can be designed for energy efficiency by integrating insulated spandrel components in space-constrained areas, such as slabs/plenums. The main aim of this study was to experimentally examine the thermal performance of an optimized curtain wall spandrel system integrated with vacuum insulation panel (VIP) as spandrel insulation. The study is based on robust experimental evaluations, augmented with appropriate numerical computations. The main study is constituted of six parts: (1) evaluation of VIP specifications and thermal properties; (2) analysis of VIP spandrel configuration, fabrication, and installation in a test building facility; (3) thermal bridge characterization of VIP spandrels; (4) monitoring and assessment of VIP durability within the spandrel cavities; (5) thermal performance analysis; and (6) assessment of related limitations and challenges, along with some further reflections. In all, 22 VIPs (each of size 600 mm2) were used. The effective thermal conductivity of VIPs ranged from 5.1–5.4 (10−3 W/mK) and the average value for initial inner pressure was approximately 4.3–5.9 mbar. Three VIP spandrel cases were fabricated and tested. The results proved that the Case 3 VIP spandrel configuration (composed of a double-layer VIP) was the most improved alternative for integrating VIPs.
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Oceano, Isabella. "The PADME charged particle spectrometer." Journal of Physics: Conference Series 2374, no. 1 (November 1, 2022): 012027. http://dx.doi.org/10.1088/1742-6596/2374/1/012027.
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The PADME experiment aims at searching signals of a dark photon A′. This is done evaluating the final state missing mass of the process e + e − → A′γ by knowing the beam energy and measuring the four-momentum of the ordinary recoil photon. The determination of this quantity, and the capability to reject the background, are the key points for the success of the experiment. Three charged particle detectors are employed to detect the positrons that have radiated a high energy photon in the target (PVeto), electrons from the beam interactions in the target or from particles which decay to final states with electrons (EVeto), and the positrons with a relatively low energy radiation in the target (HEPVeto). All three detectors are made of plastics scintillator bars placed inside the vacuum vessel of the PADME setup. PADME Commissioning took place in 2018-2019 with the beam of the Linac of the local Beam Test Facility (BTF) and results and performance of the veto stations will be presented.
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Maccari, Pietro, Pietro Arena, Ranieri Marinari, Amelia Tincani, and Alessandro Del Nevo. "Design of a Prototypical Mock-Up for the Experimental Investigation of WCLL First-Wall Performances." Energies 16, no. 4 (February 8, 2023): 1685. http://dx.doi.org/10.3390/en16041685.
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A large research effort is currently ongoing within the framework of the EUROfusion consortium for the study and design of a water-cooled lithium–lead (WCLL) breeding blanket (BB). This concept will be tested in ITER through the installation of a test blanket module (TBM) and it is one of the two candidates adopted as driver BBs in DEMO. In this framework, at the ENEA research centre of Brasimone, the realization of the experimental platform, W-HYDRA, is envisaged. The platform is dedicated to the support of the development of WCLL BB and ITER TBM and the investigation of the DEMO balance of plants. One of the most important experimental infrastructures is the water-loop facility, the aim of which is to provide water at a high pressure and temperature (PWR conditions), with a sufficient mass-flow rate and power for the experimental testing of BB and TBM components. The facility will be equipped with a vacuum chamber and an electron beam gun for the reproduction of high surface heat flux on plasma-facing components. In the present work, the design of a prototypical mock-up (MU) of the WCLL BB first wall is described. The MU is used to investigate the thermal, hydraulic and structural behavior of the current first-wall design under relevant heat loads at the expected operational conditions. The delineation of the main experimental test’s features and the instrumentation needed is assessed in the paper. A preliminary CFD calculation on the prototypical MU and the computational results are also presented.
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Khodakov, Mikhail, Aleksandr Zarvin, Valeriy Kaljada, and Nikolay Korobeishchikov. "Mass-Spectrometry of Supersonic Cluster Jets of Methane and Argon-Methane Mixtures." Siberian Journal of Physics 7, no. 3 (October 1, 2012): 84–95. http://dx.doi.org/10.54362/1818-7919-2012-7-3-84-95.
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We describe a new experimental facility LEMPUS-2, which provides experimental research in supersonic flows of gases and gas mixtures in the oil-free vacuum. Model experiments in a flow of pure argon in order to verify and test the diagnostic equipment of set-up were performed. Experimental studies of the formation of cluster beams of methane and argon-methane mixtures have been performed to determine the optimal conditions for the formation of intense molecular beams of methane clusters. We obtain an intense molecular beam of methane clusters. It was found that in a supersonic jet of large size pure methane clusters are not diagnosed by the mass spectrum of oligomeric fragments, whereas in mixtures of argon with small admixtures of methane is recorded in the mass spectrum, apparently as oligomers of methane and mixed clusters of argon-methane . It was confirmed that the clustering of methane starts at lower pressures of inhibition than argon and lead to further delay of cluster formation in argon. It is shown that for high intensity methane clusters fluxes should be used specially selected gas mixtures
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Patil, Yashashri, S. Khirwadkar, S. M. Belsare, Rajamannar Swamy, M. S. Khan, S. Tripathi, and K. Bhope. "R&D on divertor plasma facing components at the Institute for Plasma Research." Nukleonika 60, no. 2 (June 1, 2015): 285–88. http://dx.doi.org/10.1515/nuka-2015-0053.
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Abstract This paper is focused on various aspects of the development and testing of water cooled divertor PFCs. Divertor PFCs are mainly designed to absorb the heat and particle fluxes outflowing from the core plasma of fusion devices like ITER. The Divertor and First Wall Technology Development Division at the Institute for Plasma Research (IPR), India, is extensively working on development and testing of divertor plasma facing components (PFCs). Tungsten and graphite macro-brush type test mock-ups were produced using vacuum brazing furnace technique and tungsten monoblock type of test mock-ups were obtained by hot radial pressing (HRP) technique. Heat transfer performance of the developed test mock-ups was tested using high heat flux tests with different heat load conditions as well as the surface temperature monitoring using transient infrared thermography technique. Recently we have established the High Heat Flux Test Facility (HHFTF) at IPR with an electron gun EH300V (M/s Von Ardenne Anlagentechnik GmbH, Germany) having maximum power 200 kW. Two tungsten monoblock type test mock-ups were probed using HHFTF. Both of the test mock-ups successfully sustained 316 thermal cycles during high heat flux (HHF) tests. The test mock-ups were non-destructively tested using infrared thermography before and after the HHF tests. In this note we describe the detailed procedure used for testing macro-brush and monoblock type test mock-ups using in-house transient infrared thermography set-up. An acceptance criteria limit was defined for small scale macro-brush type of mock-ups using DTrefmax value and the surface temperature measured during the HHF tests. It is concluded that the heat transfer behavior of a plasma facing component was checked by the HHF tests followed by transient IR thermography. The acceptance criteria DTrefmax limit for a graphite macro-brush mock-up was found to be ~3°C while for a tungsten macro-brush mock-up it was ~5°C.
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Schell, Norbert, René V. Martins, Felix Beckmann, Hans Ulrich Ruhnau, Rüdiger Kiehn, and Andreas Schreyer. "The High Energy Materials Science Beamline at PETRA III." Materials Science Forum 571-572 (March 2008): 261–66. http://dx.doi.org/10.4028/www.scientific.net/msf.571-572.261.
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The future High Energy Materials Science Beamline HEMS at the new German high brilliance synchrotron radiation storage ring PETRA III [1] will have a main energy of 120 keV, will be fully tunable in the range of 50 to 300 keV, and will be optimized for sub-micrometer focusing with Compound Refractive Lenses and Kirkpatrick-Baez Multilayer mirrors. Design and construction is the responsibility of the Research Center Geesthacht, GKSS, with approximately 70 % of the beamtime being dedicated to Materials Research, the rest reserved for “general physics” experiments covered by DESY, Hamburg. Fundamental research will encompass metallurgy, physics and chemistry. For first experiments in investigating grain-grain-interactions a dedicated 3D-microstructure-mapper will be designed. Applied research for manufacturing process optimization will benefit from the high flux in combination with ultra-fast detector systems allowing complex and highly dynamic in-situ studies of microstructural transformations. The beamline infrastructure will allow easy accommodation of large user provided equipment. Experiments targeting the industrial user community will be based on well established techniques with standardised evaluation, allowing "full service" measurements. Environments for strain mapping [2] on large structural components up to 1 t will be provided as well as automated investigations of large numbers of samples, e.g. for tomography and texture determination. The current design for the beamline (P07 in sector 5 of the future experimental hall) consists of a nearly five meter in-vacuum undulator source (U19-5) optimized for high energies, a general optics hutch, an in-house test facility and three independent experimental hutches working alternately, plus additional set-up and storage space for long-term experiments. HEMS should be operational in spring 2009 as one of the first beamlines running at PETRA III.
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ROUX, R. "CONCEPTION OF PHOTOINJECTORS FOR THE CTF3 EXPERIMENT." International Journal of Modern Physics A 22, no. 22 (September 10, 2007): 3925–41. http://dx.doi.org/10.1142/s0217751x07037524.
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In the framework of the CLIC Test Facility (CTF3) under development at CERN, LAL-Orsay is responsible for the construction of two photo-injectors for two different linacs. One, dedicated for the so called “drive beam linac” must fulfil very demanding specifications. The RF gun has to provide a high quality beam composed of more than 2,000 bunches containing 2.33 nC of charge each in one RF pulse. The model adopted is inspired from the CERN 3 GHz 2-1/2 cell type IV RF gun. We will summarize all the studies performed on the RF design and on the beam dynamics. The vacuum issue has been also carefully investigated. The constraints on the second photo-injector are less severe since it must be operated with one or 64 bunches of 0.5 nC each for the so called “probe beam linac”. It will also be a 2.5 cell gun at 3 GHz but its design will be substantially different with respect to the former. This last project has only recently begun and therefore we will show only the preliminary results of the RF and of the beam dynamics simulations.
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Dickstein, Dylan, Arian Ghazari, Warren Nadvornick, Michael Liao, Brandon Carson, Mark Goorsky, and Nasr Ghoniem. "Mass loss, sublimation, and surface damage of lanthanum hexaboride in an arc jet plasma." Journal of Applied Physics 133, no. 5 (February 7, 2023): 055101. http://dx.doi.org/10.1063/5.0130131.
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An experimental and simulation-based approach is used to determine the effects of an arc jet plasma on the refractory ceramic material lanthanum hexaboride ([Formula: see text]). Experiments are performed at the High Energy Flux Test facilitY (HEFTY) located at UCLA. An SG-100 plasma jet generates an argon plasma into a vacuum chamber and imparts a maximum heat flux of 19.5 MW/[Formula: see text] onto [Formula: see text] disks. Heat flux results are calibrated using a combination of thermocouple data as well as multiphysics numerical simulations in COMSOL, which aim to replicate the testing environment. Moreover, material characterization tools including scanning electron microscopy, energy-dispersive x-ray spectroscopy, x-ray diffraction, and optical profilometry are used to better understand the mechanisms by which [Formula: see text] loses mass through evaporation, sublimation, and surface damage during an arc jet exposure. It is determined that a minimum energy fluence of 200–300 MJ/[Formula: see text] produces a consistent [Formula: see text] melt pool and that an incident heat flux of 19.5 MW/[Formula: see text] results in a 0.11 mm/s surface recession rate.
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Vakkada Ramachandran, Abhilash, Miracle Israel Nazarious, Thasshwin Mathanlal, María-Paz Zorzano, and Javier Martín-Torres. "Space Environmental Chamber for Planetary Studies." Sensors 20, no. 14 (July 18, 2020): 3996. http://dx.doi.org/10.3390/s20143996.
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We describe a versatile simulation chamber that operates under representative space conditions (pressures from < 10−5 mbar to ambient and temperatures from 163 to 423 K), the SpaceQ chamber. This chamber allows to test instrumentation, procedures, and materials and evaluate their performance when exposed to outgassing, thermal vacuum, low temperatures, baking, dry heat microbial reduction (DHMR) sterilization protocols, and water. The SpaceQ is a cubical stainless-steel chamber of 27,000 cm3 with a door of aluminum. The chamber has a table which can be cooled using liquid nitrogen. The chamber walls can be heated (for outgassing, thermal vacuum, or dry heat applications) using an outer jacket. The chamber walls include two viewports and 12 utility ports (KF, CF, and Swagelok connectors). It has sensors for temperature, relative humidity, and pressure, a UV–VIS–NIR spectrometer, a UV irradiation lamp that operates within the chamber as well as a stainless-steel syringe for water vapor injection, and USB, DB-25 ports to read the data from the instruments while being tested inside. This facility has been specifically designed for investigating the effect of water on the Martian surface. The core novelties of this chamber are: (1) its ability to simulate the Martian near-surface water cycle by injecting water multiple times into the chamber through a syringe which allows to control and monitor precisely the initial relative humidity inside with a sensor that can operate from vacuum to Martian pressures and (2) the availability of a high-intensity UV lamp, operating from vacuum to Martian pressures, within the chamber, which can be used to test material curation, the role of the production of atmospheric radicals, and the degradation of certain products like polymers and organics. For illustration, here we present some applications of the SpaceQ chamber at simulated Martian conditions with and without atmospheric water to (i) calibrate the ground temperature sensor of the Engineering Qualification Model of HABIT (HabitAbility: Brines, Irradiation and Temperature) instrument, which is a part of ExoMars 2022 mission. These tests demonstrate that the overall accuracy of the temperature retrieval at a temperature between −50 and 10 °C is within 1.3 °C and (ii) investigate the curation of composite materials of Martian soil simulant and binders, with added water, under Martian surface conditions under dry and humid conditions. Our studies have demonstrated that the regolith, when mixed with super absorbent polymer (SAP), water, and binders exposed to Martian conditions, can form a solid block and retain more than 80% of the added water, which may be of interest to screen radiation while maintaining a low weight.
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Wang, Yan, Jan Oellerich, Carsten Baars, and Martin Mittwollen. "Concept of Contamination Control Door for DEMO and Proof of Principle Design." Journal of Nuclear Engineering 4, no. 1 (March 1, 2023): 228–40. http://dx.doi.org/10.3390/jne4010018.
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During the maintenance period of a future fusion reactor power plant, called DEMOnstration Power Plant (DEMO), remotely handled casks are required to confine and handle DEMO in-vessel components during their transportation between the reactor and the active maintenance facility. In order to limit the dispersion of activated dust, a Contamination Control Door (CCD) is designed to be placed at an interface between separable containments (e.g., vacuum vessels and casks) to inhibit the release of contamination at the interface between them. The remotely operated CCD—technically, a double lidded door system—consists of two separable doors (the cask door and port door) and three different locking mechanisms: (i) between the cask door and cask, (ii) between the cask door and port door and (iii) between the port door and port. The locking mechanisms are selected and assessed according to different criteria, and the structure of the CCD is optimized using an Abaqus Topology Optimization Module. Due to the elastic properties of the CCD, deflections will occur during the lifting procedure, which may lead to malfunctions of the CCD. A test rig is developed to investigate the performance of high-risk components in the CCD in the case of deflections and also malpositioning. Misalignment can be induced along three axes and three angles intentionally to test the single components and items. The aim is to identify a possible range of operating in the case of misalignments. It is expected that the proposed CCD design should be able to operate appropriately in the case of ±3 mm translational misalignments and ±1° rotational misalignments.
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Mykhaylyk, V. B., A. Wagner, and H. Kraus. "Non-contact luminescence lifetime cryothermometry for macromolecular crystallography." Journal of Synchrotron Radiation 24, no. 3 (April 4, 2017): 636–45. http://dx.doi.org/10.1107/s1600577517003484.
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Temperature is a very important parameter when aiming to minimize radiation damage to biological samples during experiments that utilize intense ionizing radiation. A novel technique for remote, non-contact,in situmonitoring of the protein crystal temperature has been developed for the new I23 beamline at the Diamond Light Source, a facility dedicated to macromolecular crystallography (MX) with long-wavelength X-rays. The temperature is derived from the temperature-dependent decay time constant of luminescence from a minuscule scintillation sensor (<0.05 mm3) located in very close proximity to the sample under test. In this work the underlying principle of cryogenic luminescence lifetime thermometry is presented, the features of the detection method and the choice of temperature sensor are discussed, and it is demonstrated how the temperature monitoring system was integrated within the viewing system of the endstation used for the visualization of protein crystals. The thermometry system was characterized using a Bi4Ge3O12crystal scintillator that exhibits good responsivity of the decay time constant as a function of temperature over a wide range (8–270 K). The scintillation sensor was calibrated and the uncertainty of the temperature measurements over the primary operation temperature range of the beamline (30–150 K) was assessed to be ±1.6 K. It has been shown that the temperature of the sample holder, measured using the luminescence sensor, agrees well with the expected value. The technique was applied to characterize the thermal performance of different sample mounts that have been used in MX experiments at the I23 beamline. The thickness of the mount is shown to have the greatest impact upon the temperature distribution across the sample mount. Altogether, these tests and findings demonstrate the usefulness of the thermometry system in highlighting the challenges that remain to be addressed for the in-vacuum MX experiment to become a reliable and indispensable tool for structural biology.
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Andrés Hernández, M. Dolores, Andreas Hilboll, Helmut Ziereis, Eric Förster, Ovid O. Krüger, Katharina Kaiser, Johannes Schneider, et al. "Overview: On the transport and transformation of pollutants in the outflow of major population centres – observational data from the EMeRGe European intensive operational period in summer 2017." Atmospheric Chemistry and Physics 22, no. 9 (May 5, 2022): 5877–924. http://dx.doi.org/10.5194/acp-22-5877-2022.
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Abstract. Megacities and other major population centres (MPCs) worldwide are major sources of air pollution, both locally as well as downwind. The overall assessment and prediction of the impact of MPC pollution on tropospheric chemistry are challenging. The present work provides an overview of the highlights of a major new contribution to the understanding of this issue based on the data and analysis of the EMeRGe (Effect of Megacities on the transport and transformation of pollutants on the Regional to Global scales) international project. EMeRGe focuses on atmospheric chemistry, dynamics, and transport of local and regional pollution originating in MPCs. Airborne measurements, taking advantage of the long range capabilities of the High Altitude and LOng Range Research Aircraft (HALO, https://www.halo-spp.de, last access: 22 March 2022), are a central part of the project. The synergistic use and consistent interpretation of observational data sets of different spatial and temporal resolution (e.g. from ground-based networks, airborne campaigns, and satellite measurements) supported by modelling within EMeRGe provide unique insight to test the current understanding of MPC pollution outflows. In order to obtain an adequate set of measurements at different spatial scales, two field experiments were positioned in time and space to contrast situations when the photochemical transformation of plumes emerging from MPCs is large. These experiments were conducted in summer 2017 over Europe and in the inter-monsoon period over Asia in spring 2018. The intensive observational periods (IOPs) involved HALO airborne measurements of ozone and its precursors, volatile organic compounds, aerosol particles, and related species as well as coordinated ground-based ancillary observations at different sites. Perfluorocarbon (PFC) tracer releases and model forecasts supported the flight planning, the identification of pollution plumes, and the analysis of chemical transformations during transport. This paper describes the experimental deployment and scientific questions of the IOP in Europe. The MPC targets – London (United Kingdom; UK), the Benelux/Ruhr area (Belgium, the Netherlands, Luxembourg and Germany), Paris (France), Rome and the Po Valley (Italy), and Madrid and Barcelona (Spain) – were investigated during seven HALO research flights with an aircraft base in Germany for a total of 53 flight hours. An in-flight comparison of HALO with the collaborating UK-airborne platform Facility for Airborne Atmospheric Measurements (FAAM) took place to assure accuracy and comparability of the instrumentation on board. Overall, EMeRGe unites measurements of near- and far-field emissions and hence deals with complex air masses of local and distant sources. Regional transport of several European MPC outflows was successfully identified and measured. Chemical processing of the MPC emissions was inferred from airborne observations of primary and secondary pollutants and the ratios between species having different chemical lifetimes. Photochemical processing of aerosol and secondary formation or organic acids was evident during the transport of MPC plumes. Urban plumes mix efficiently with natural sources as mineral dust and with biomass burning emissions from vegetation and forest fires. This confirms the importance of wildland fire emissions in Europe and indicates an important but discontinuous contribution to the European emission budget that might be of relevance in the design of efficient mitigation strategies. The present work provides an overview of the most salient results in the European context, with these being addressed in more detail within additional dedicated EMeRGe studies. The deployment and results obtained in Asia will be the subject of separate publications.
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Alhawari, Abdalhadi, and Phalguni Mukhopadhyaya. "Construction and Calibration of a Unique Hot Box Apparatus." Energies 15, no. 13 (June 26, 2022): 4677. http://dx.doi.org/10.3390/en15134677.
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A variety of mathematical models are available to estimate the thermal performance of buildings. Nevertheless, mathematical models predict the thermal performance of buildings that might differ from the actual performance. The hot box is a widely-used test apparatus to assess the actual thermal performance of various building envelope components (walls, roofs, windows) in the laboratory. This paper presents the process of designing, constructing, and calibrating a unique small-scale hot box apparatus. Despite its smaller metering area (1.0 m × 1.0 m), this apparatus met the key requirements (below ±0.25 °C fluctuations in chambers’ air temperature, and below 2.0% variation from the point-to-point temperature in reference to the temperature difference across the specimen) as prescribed in the ASTM C1363 and ISO 8990 standards. The walls of this apparatus are uniquely constructed using vacuum insulation panels or VIPs. The efficient and novel use of VIPs and workmanship during the construction of the apparatus are demonstrated through the temperature stability within the chambers. The achieved range of temperature steadiness below ±0.05 °C and point-to-point temperature variation below 1.0% of the temperature difference across the specimen allow for this apparatus to be considered unique among the calibrated hot box categories reported in the literature. In addition, having an affordable, simple-to-operate, and high-accuracy facility offers a great opportunity for researchers and practitioners to investigate new ideas and solutions. The apparatus was calibrated using two extruded polystyrene foam (XPS) specimens with thicknesses of 2″ and 4″. The calibration exercise indicates small differences between results obtained numerically, theoretically, and experimentally (below 3.0%). Ultimately, the apparatus was employed to measure the thermal properties of a specimen representing a lightweight steel framing (LSF) wall system, which is commonly used in cold climates. The results obtained experimentally were then compared to the ones estimated numerically using a 3D finite element modelling tool. The difference between the results obtained by both methods was below 9.0%.
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Carra, F., C. Charrondiere, M. Guinchard, and O. Sacristan de Frutos. "Design and Construction of an Instrumentation System to Capture the Response of Advanced Materials Impacted by Intense Proton Pulses." Shock and Vibration 2021 (April 2, 2021): 1–20. http://dx.doi.org/10.1155/2021/8855582.
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In recent years, significant efforts were taken at CERN and other high-energy physics laboratories to study and predict the consequences of particle beam impacts on devices such as collimators, targets, and dumps. The quasi-instantaneous beam impact raises complex dynamic phenomena which may be simulated resorting to implicit codes, for what concerns the elastic or elastoplastic solid regime. However, when the velocity of the produced stress waves surpasses the speed of sound and we enter into the shock regime, highly nonlinear numerical tools, called Hydrocodes, are usually necessary. Such codes, adopting very extensive equations of state, are also able to well reproduce events such as changes of phase, spallation, and explosion of the target. In order to derive or validate constitutive numerical models, experiments were performed in the past years at CERN HiRadMat facility. This work describes the acquisition system appositely developed for such experiments, whose main goal is to verify, mostly in real time, the response of matter when impacted by highly energetic proton beams. Specific focus is given to one of the most comprehensive testing campaigns, named “HRMT-14.” In this experiment, energy densities with peaks up to 20 kJ/cm3 were achieved on targets of different materials (metallic alloys, graphite, and diamond composites), by means of power pulses with a population up to 3 × 1013 p at 450 GeV. The acquisition relied on embarked instrumentation (strain gauges, temperature probes, and vacuum sensors) and on remote acquisition devices (laser Doppler vibrometer and high-speed camera). Several studies have been performed to verify the dynamic behaviour of the standard strain gauges and the related cabling in the chosen range of acquisition frequency (few MHz). The strain gauge measurements were complemented by velocity measurements performed using a customised long-range laser Doppler vibrometer (LDV) operating in the amplitude range of 24 m/s; the LDV, together with the high-speed video camera (HSVC), has been placed at a distance of 40 m from the target to minimize radiation damage. In addition, due to the large number of measuring points, a radiation-hard multiplexer switch has been used during the experiment: this system was designed to fulfil the multiple requirements in terms of bandwidth, contact resistances, high channel reduction, and radiation resistance. Shockwave measurements and intense proton pulse effects on the instrumentation are described, and a brief overlook of the comparison of the results of the acquisition devices with simulations, performed with the finite element tool Autodyn, is given. Generally, the main goal of such experiments is to benchmark and improve material models adopted on the tested materials in explicit simulations of particle beam impact, a design scenario in particle accelerators, performed by means of Autodyn. Simulations based on simplified strain-dependent models, such as Johnson–Cook, are run prior to the experiment. The model parameters are then updated in order to fit the experimental response, under a number of load cases to ensure repeatability of the model. This paper, on the other hand, mostly focuses on the development of the DAQ for HiRadMat experiments, and in particular for HRMT-14. Such development, together with the test design and run, as well as postmortem examination, spanned over two years, and its fundamental results, mostly in terms of dedicated instrumentation, have been used in all successive HiRadMat experiments as of 2014. This experimental method can also find applications for materials undergoing similarly high strain rates and temperature changes (up to 106 s-1 and 10.000 K, respectively), for example, in the case of experiments involving fast and intense loadings on materials and structures.
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Grabe, Martin. "STG-CT: High-vacuum plume test facility for chemical thrusters." Journal of large-scale research facilities JLSRF 2 (August 17, 2016). http://dx.doi.org/10.17815/jlsrf-2-139.
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The STG-CT, operated by the DLR Institute for Aerodynamics and Flow Technology in Göttingen, is a vacuum facility specically designed to provide and maintain a space-like vacuum environment for researching plume flow and plume impingement from satellite reaction control thrusters. Its unique liquid-helium driven cryopump of 30m2 allows maintaining a background pressure <10^-5 mbar even when molecular hydrogen is a plume constituent.
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Neumann, Andreas. "STG-ET: DLR electric propulsion test facility." Journal of large-scale research facilities JLSRF 3 (April 7, 2017). http://dx.doi.org/10.17815/jlsrf-3-156.
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DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET). This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target with low sputtering, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.
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Sun, Mingming, and Yi Zheng. "Neutral Plume Simulation of Ion Thruster in Vacuum Facility With Cooled Target." IEEE Transactions on Plasma Science, 2020, 1–7. http://dx.doi.org/10.1109/tps.2020.2997243.
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Wang, Yusa, Zijian Zhao, Dongjie Hou, Xiongtao Yang, Can Chen, Xinqiao Li, Yuxuan Zhu, et al. "The 100-m X-ray test facility at IHEP." Experimental Astronomy, October 22, 2022. http://dx.doi.org/10.1007/s10686-022-09872-7.
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AbstractThe 100-m X-ray Test Facility of the Institute of High Energy Physics (IHEP) was initially proposed in 2012 for the test and calibration of the X-ray detectors of the Hard X-ray Modulation Telescope (HXMT) with the capability to support future X-ray missions. The large instrument chamber connected with a long vacuum tube can accommodate the X-ray mirror, focal plane detector and other instruments. The X-ray sources are installed at the other end of the vacuum tube with a distance of 105 m, which can provide an almost parallel X-ray beam covering 0.2$$\sim$$ ∼ 60 keV energy band. The X-ray mirror modules of the Einstein Probe (EP) and the enhanced X-ray Timing and Polarimetry mission (eXTP) and payload of the Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) have been tested and calibrated with this facility. It has been also used to characterize the focal plane camera and aluminum filter used on the Einstein Probe. In this paper, we will introduce the overall configuration and capability of the facility, and give a brief introduction of some calibration results performed with this facility.
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Neumann, Andreas, Jens Simon, and Jens Schmidt. "Thrust measurement and thrust balance development at DLR’s electric propulsion test facility." EPJ Techniques and Instrumentation 8, no. 1 (November 23, 2021). http://dx.doi.org/10.1140/epjti/s40485-021-00074-7.
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AbstractElectric space propulsion thrusters only produce low thrust forces. For the fulfillment of a space mission this implies long thruster runtimes, and this entails long qualification times on ground. For such long testing times, a ground facility requires a vacuum chamber and a powerful pumping system which can guarantee high vacuum over extended times and under thruster gas load. DLR’s STG-ET is such a ground test facility. It has a high pumping capability for the noble gases typically used as propellants. One basic diagnostic tool is a thrust measurement device, among various other diagnostic systems required for electric propulsion testing, e.g. beam diagnostics. At DLR we operate a thrust balance developed by the company AST with a thrust measurement range of 250 mN and capable of thruster weights up to 40 kg. Adversely, it is a bulky and heavy device and all upgrades and qualification work needs to be done in a large vacuum chamber. In order to have a smaller device at hand a second thrust stand is under development at DLR. The idea is to have a light and compact balance that could also be placed in one of the smaller DLR vacuum chambers. Furthermore, the calibration is more robust and the whole device is equipped with a watercooled housing. First tests are promising and showed a resolution well below 1 mN. In this paper we give background information about the chamber, describe the basics of thrust measurement and the development of a new balance.
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Schiedel, Matthew J., Cynthia A. Cruickshank, and Christopher M. Baldwin. "In Situ Experimental Validation of therm Finite Element Analysis for a High R-Value Wall Using Vacuum Insulation Panels." Journal of Solar Energy Engineering 137, no. 6 (September 22, 2015). http://dx.doi.org/10.1115/1.4031512.
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This paper details the method used for a theoretical evaluation of Team Ontario's, U.S. Department of Energy Solar Decathlon 2013 entrant, high R-value wall using vacuum insulation panels (VIPs). The purpose is to determine a theoretical whole-wall thermal resistance to be used for energy modeling. Theoretical simulations are performed in therm, a two-dimensional finite element heat transfer modeling program, and an in situ experimental validation is conducted in Carleton University's Vacuum Insulation Test Facility located in Ottawa, Ontario, Canada. The theoretical model is refined based on the experimental study, and a whole-wall thermal resistance of Team Ontario's wall design is determined to be 9.4 m2·K/W (53 h·ft2·°F/Btu) at an exterior design temperature of −18 °C (0 °F).
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Kondo, Hiroo, Takuji Kanemura, Tomohiro Furukawa, Yasushi Hirakawa, Eiichi Wakai, and Juan Knaster. "Experimental Study on Cavitation of a Liquid Lithium Jet for International Fusion Materials Irradiation Facility." Journal of Nuclear Engineering and Radiation Science 3, no. 4 (July 31, 2017). http://dx.doi.org/10.1115/1.4036513.
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A liquid Li jet flowing at 15 m/s under a high vacuum of 10−3 Pa is intended to serve as a beam target (Li target) in the planned International Fusion Materials Irradiation Facility (IFMIF). The engineering validation and engineering design activities (EVEDA) for the IFMIF are being implemented under the broader approach (BA) agreement. As a major activity of the Li target facility, the EVEDA Li test loop (ELTL) was constructed by the Japan Atomic Energy Agency. A stable Li target under the IFMIF conditions (Li temperature: 523.15 K, velocity: 15 m/s, and vacuum pressure: 10−3 Pa) was demonstrated using ELTL. This study focuses on a cavitationlike acoustic noise detected in a downstream conduit where the Li target flowed under vacuum conditions. This noise was investigated using acoustic-emission (AE) sensors installed at eight locations via acoustic wave guides. The sound intensity of the acoustic noise was examined against the cavitation number of the Li target. In addition, two types of frequency analysis, namely, fast Fourier transform (FFT) and continuous wavelet transform (CWT), were performed to characterize the acoustic noise. Owing to the acoustic noise's intermittency, high frequency, and the dependence on cavitation number, we conclude that this acoustic noise is generated when cavitation bubbles collapse and/or the structural material of the pipe is cracked because of the collapse of cavitation bubbles (cavitation pitting). The location of the cavitation was fundamental for presuming the mechanism. In this study, the propagation of acoustic waves among AE sensors placed at three locations was used to localize the cavitation and a method to determine the location of cavitation was formulated. As a result, we found that cavitation occurred only in a narrow area where the Li target impinged on the downstream conduit; therefore, we concluded that this cavitation was induced by the impingement. The design of the downstream conduit of the IFMIF Li target facility should be tackled in future based on information obtained in this study.
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Ayyadevara, Narayana Teja, Balaji Subramanian, and Naga Suresh Meda. "Experimental and Computational Investigation for Accelerated Testing and Characterization of Next-generation Steam Turbine Rotors." Journal of Thermal Science and Engineering Applications, July 22, 2022, 1–16. http://dx.doi.org/10.1115/1.4055069.
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Abstract A unique set of test protocols is developed to evaluate new materials for high temperature and pressure applications (>700 °C and 310 bar) in next-generation thermal power plants. These protocols employ accelerated testing processes to provide a realistic estimate of a component's life under actual field operating conditions. A state-of-the-art experimental facility to characterize turbine rotors for Advanced Ultra-Supercritical conditions was commissioned at Bharat Heavy Electricals Limited, in India. An alloy rotor mounted inside the test chamber is subjected to cyclic thermal and mechanical stresses at elevated temperatures for a predetermined number of thermal cycles to estimate its creep and fatigue life. Cyclic thermal and mechanical loads are applied by sequentially exposing rotors rotating at high speed to transient heating, steady-state soaking, and transient cooling. These transient heating and cooling processes are carefully designed to achieve specific temperature gradients inside the rotor bulk. The rotor is heated in a vacuum by thermal radiation from heater coils. In contrast, rotor cooling is accomplished by circulating relatively cold nitrogen gas through the chamber. Preliminary findings from accelerated tests are reported here. Two computational fluid dynamics (CFD) models were developed to support the transient heating and cooling experiments. Good agreement is observed between CFD simulations and measurements, validating the approach presented. This facility, established under a clean energy research initiative, plays a vital role in reducing the time and cost involved in finding suitable alloy materials, thus advancing the development of ultra-efficient thermal power plants
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Ahdida, C., A. Akmete, R. Albanese, J. Alt, A. Alexandrov, A. Anokhina, S. Aoki, et al. "The SHiP experiment at the proposed CERN SPS Beam Dump Facility." European Physical Journal C 82, no. 5 (May 2022). http://dx.doi.org/10.1140/epjc/s10052-022-10346-5.
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AbstractThe Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50$$\mathrm { \,m}$$ m long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400$$\,\mathrm {GeV}$$ GeV protons, the experiment aims at profiting from the $$4\times 10^{19}$$ 4 × 10 19 protons per year that are currently unexploited at the SPS, over a period of 5–10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few $${\mathrm {\,MeV\!/}c^2}$$ MeV / c 2 up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end.
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Schwertheim, Alexander, and Aaron Knoll. "Low power thrust measurements of the water electrolysis Hall effect thruster." CEAS Space Journal, March 1, 2021. http://dx.doi.org/10.1007/s12567-021-00350-y.
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AbstractWe propose that a Hall effect thruster could be modified to operate on the products of water electrolysis. Such a thruster would exploit the low cost and high storability of water while producing gaseous hydrogen and oxygen in-situ as they are required. By supplying the anode with oxygen and the cathode with hydrogen, the poisoning of the cathode is mitigated. The water electrolysis Hall effect thruster (WET-HET) has been designed to demonstrate this concept. The dimensions of the WET-HET have been optimized for oxygen operation using PlasmaSim, a zero-dimensional particle in cell code. We present the first direct thrust measurements of the WET-HET. A hanging pendulum style thrust balance is used to measure the thrust of the WET-HET while operating in the Boltzmann vacuum facility within the Imperial Plasma Propulsion Laboratory. For this test the beam was neutralized using a filament plasma bridge neutralizer operating on krypton. We find thrust, specific impulse, and thrust efficiency all increase linearly with power for values between 400 and 1050 W. Increasing the mass flow rate from 0.96 to 1.85 mg/s increases thrust at the expense of specific impulse. Changing mass flow rate was found to have little impact on the thrust efficiency over this range. An optimal radial magnetic flux density of 403 G at the exit plane is found. Further increases to the magnetic field beyond this point were found to decrease the thrust, specific impulse and thrust efficiency, whereas the discharge voltage increased monotonically with increasing magnetic field for a given input power. It was found that the experimental thruster performance was lower than the simulation results from PlasmaSim. However, the general trends in performance as a function of power and propellant mass flow rate were preserved. We attribute a portion of this discrepancy to the inability of the simulation to model the energy absorbed by the covalent bond of the oxygen molecule. For the powers and mass flow rates surveyed we measured thrust ranging from 4.52$$\pm 0.18\,$$ ± 0.18 to 8.45$$\pm 0.18\,$$ ± 0.18 mN, specific impulse between 324$$\pm 12\,$$ ± 12 and 593$$\pm 12\,$$ ± 12 s, and anode thrust efficiencies between 1.34$$\pm 0.10\,$$ ± 0.10 and 2.34$$\pm 0.10\,$$ ± 0.10 %.