Статті в журналах: "Nanosecond precision"

1

Ye, Y., H. Li, J. Li, and G. Gong. "Sub-nanosecond synchronization implementation in pure Xilinx Kintex-7 FPGA." Journal of Instrumentation 16, no. 11 (November 1, 2021): P11036. http://dx.doi.org/10.1088/1748-0221/16/11/p11036.

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Abstract White Rabbit (WR) provides high-performance synchronization with sub-nanosecond accuracy and picoseconds precision, and it has been included in the new High Accuracy Default PTP Profile in the IEEE 1588-2019. As an open-source project, WR Precision Time Protocol (WR-PTP) core has been implemented in different FPGA platforms with dedicated clock circuits. This paper presents a novel approach to achieve the WR function in Xilinx Kintex-7 FPGA depending on the on-chip resource. This approach could achieve sub-nanosecond accuracy and tens of picoseconds precision, simplifying WR devices' hardware design and making it possible to port the WR PTP core to many mature hardware platforms.

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2

Eyler, E. E., A. Yiannopoulou, S. Gangopadhyay, and N. Melikechi. "Chirp-free nanosecond laser amplifier for precision spectroscopy." Optics Letters 22, no. 1 (January 1, 1997): 49. http://dx.doi.org/10.1364/ol.22.000049.

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3

Hare, B. M., O. Scholten, A. Bonardi, S. Buitink, A. Corstanje, U. Ebert, H. Falcke, et al. "LOFAR Lightning Imaging: Mapping Lightning With Nanosecond Precision." Journal of Geophysical Research: Atmospheres 123, no. 5 (March 16, 2018): 2861–76. http://dx.doi.org/10.1002/2017jd028132.

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4

Sun, Yanwen, Franz-Josef Decker, James Turner, Sanghoon Song, Aymeric Robert, and Diling Zhu. "Pulse intensity characterization of the LCLS nanosecond double-bunch mode of operation." Journal of Synchrotron Radiation 25, no. 3 (March 27, 2018): 642–49. http://dx.doi.org/10.1107/s160057751800348x.

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The recent demonstration of the `nanosecond double-bunch' operation mode,i.e.two X-ray pulses separated in time between 0.35 and hundreds of nanoseconds and by increments of 0.35 ns, offers new opportunities to investigate ultrafast dynamics in diverse systems of interest. However, in order to reach its full potential, this mode of operation requires the precise characterization of the intensity of each X-ray pulse within each pulse pair for any time separation. Here, a transmissive single-shot diagnostic that achieves this goal for time separations larger than 0.7 ns with a precision better than 5% is presented. It also provides real-time monitoring feedback to help tune the accelerator parameters to deliver double pulse intensity distributions optimized for specific experimental goals.

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5

Liu, Ying, Wenhai Jiao, Longxia Xu, and Xiaohui Li. "Differential Timing Method Based on Modified Traceability Model." Journal of Navigation 73, no. 6 (June 22, 2020): 1326–39. http://dx.doi.org/10.1017/s0373463320000314.

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The common view time transfer and two-way time and frequency transfer methods are currently the main means for achieving time synchronisation at nanosecond level. However, these methods have some limitations in real time and cost, which limit their wide applications in many fields, such as time synchronisation among base stations of the upcoming 5G network. In order to meet the requirements of nanosecond time synchronisation, a low-cost differential timing method is proposed in this paper by changing the manner of generation of traceability model parameters in GNSS navigation messages. The time deviation between GNSS system time and the timing laboratory that maintains Coordinated Universal Time (UTC) kept by timing laboratory named k (UTC(k)) is monitored by receiving the GNSS signal in space with monitoring receivers. The new traceability model parameters are generated with the monitored time deviations and then broadcast to users through the GNSS navigation message. The precision of the one-way timing method can be improved from tens of nanoseconds to the order of several nanoseconds with the proposed method. In addition, there are obvious advantages to carry out this method on the geostationary satellites in the BeiDou navigation satellite (BDS) constellation. The proposed method is verified on an experimental platform based on the UTC(NTSC) time frequency signal and the geostationary satellites in the BDS-3 constellation.

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6

Zhang, Xing Hong, Wei Cai, Feng Yun Xiang, Tian Heng Zhang, and Shu Xiang Liu. "A Novel Precision Ultrasonic Thermometer." Advanced Materials Research 328-330 (September 2011): 1768–71. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1768.

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A new type of temperature measurement apparatus is designed by utilizing the characteristic that the velocity of the ultrasonic wave varies with the temperature through the medium, with both merits low cost and high precision. This paper introduces the principle of ultrasonic thermometer and puts forward the realization of hardware and software of thermometer, and details the special software subdivision algorithm which is used to measure the ultrasonic transmission time accurately. The experimental results indicate that the thermometer achieves the measure of the ultrasonic wave transmitting time with nanosecond level. The key problems are solved in the practical application of the ultrasonic temperature measuring technology, and the resolution of the temperature measurement is better than 0.001 centigrade.

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7

Shi Huicai, 石会财, 曹劭文 Cao Shaowen, 张蓉竹 Zhang Rongzhu, and 孙年春 Sun Nianchun. "Effect of nanosecond pulse control precision on multi-beam beams." Infrared and Laser Engineering 46, no. 12 (2017): 1206003. http://dx.doi.org/10.3788/irla201746.1206003.

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8

Yang, Kai, William Paul, Soo-Hyon Phark, Philip Willke, Yujeong Bae, Taeyoung Choi, Taner Esat, Arzhang Ardavan, Andreas J. Heinrich, and Christopher P. Lutz. "Coherent spin manipulation of individual atoms on a surface." Science 366, no. 6464 (October 24, 2019): 509–12. http://dx.doi.org/10.1126/science.aay6779.

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Achieving time-domain control of quantum states with atomic-scale spatial resolution in nanostructures is a long-term goal in quantum nanoscience and spintronics. Here, we demonstrate coherent spin rotations of individual atoms on a surface at the nanosecond time scale, using an all-electric scheme in a scanning tunneling microscope (STM). By modulating the atomically confined magnetic interaction between the STM tip and surface atoms, we drive quantum Rabi oscillations between spin-up and spin-down states in as little as ~20 nanoseconds. Ramsey fringes and spin echo signals allow us to understand and improve quantum coherence. We further demonstrate coherent operations on engineered atomic dimers. The coherent control of spins arranged with atomic precision provides a solid-state platform for quantum-state engineering and simulation of many-body systems.

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9

Liu, Yong, Yong Jiang, Chunsheng Guo, Shihui Deng, and Huanghai Kong. "Experimental Research on Machining Localization and Surface Quality in Micro Electrochemical Milling of Nickel-Based Superalloy." Micromachines 9, no. 8 (August 14, 2018): 402. http://dx.doi.org/10.3390/mi9080402.

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Micro electrochemical machining is becoming increasingly important in the microfabrication of metal parts. In this paper, the machining characteristics of micro electrochemical milling with nanosecond pulse were studied. Firstly, a mathematical model for the localization control of micro electrochemical milling with nanosecond pulse was established. Secondly, groups of experiments were conducted on nickel-based superalloy and the effects of parameters such as applied voltage, pulse on time, pulse period, electrolyte concentration and electrode diameter on machining localization and surface roughness were analyzed. Finally, by using the optimized machining parameters, some 2D complex shapes and 3D square cavity structures with good shape precision and good surface quality were successfully obtained. It was proved that the micro electrochemical milling with nanosecond pulse technique is an effective machining method to fabricate metal microstructures.

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10

Zemann, Richard, Friedrich Bleicher, and Reinhard Zisser-Pfeifer. "Electrochemical micromachining with ultra short voltage pulses." Archive of Mechanical Engineering 59, no. 3 (October 1, 2012): 313–27. http://dx.doi.org/10.2478/v10180-012-0016-z.

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The machining technology of electrochemical micromachining with ultra short voltage pulses (μPECM) is based on the already well-established fundamentals of common electrochemical manufacturing technologies. The enormous advantage of the highest manufacturing precision underlies the fact of the extremely small working gaps achievable through ultra short voltage pulses in nanosecond duration. This describes the main difference with common electrochemical technologies. With the theoretical resolution of 10 nm, this technology enables high precision manufacturing [4].

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11

You, Bu Xin, He Zhi Liu, Peng Tian, Jia Xu, and Jing Bu. "A Study of High-Precision Internal Clock Maintenance Method." Advanced Materials Research 765-767 (September 2013): 2407–10. http://dx.doi.org/10.4028/www.scientific.net/amr.765-767.2407.

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In the engineering application, we put forward higher request to the device in the clock accuracy and stability. In this paper, we can modify GPS second pulse online which based on the GPS timing and combine high precision crystal in order to reduce its random error. And on this basis, we put forward a method of dynamic compensation to do the real-time numerical compensation in the apparatus. It can be used as accurate information for the device using nanosecond, not only has high precision, but also simple to implement, and has higher application value in engineering.

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12

Wu, Congyi, Weinan Liu, Min Li, Yu Huang, Guojun Zhang, and Youmin Rong. "Phenolic resin plate precision cutting by ultraviolet nanosecond laser ablation regulation." Optik 243 (October 2021): 167481. http://dx.doi.org/10.1016/j.ijleo.2021.167481.

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13

Xu, Dong, Yao Yao, Xing Fu, and Chao Wang. "Design of Micromachining System Based on Nanosecond Pulsed Laser." Key Engineering Materials 645-646 (May 2015): 1049–53. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.1049.

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In recent years, pulsed laser processing technology is widely used in MEMS device manufacturing, aerospace technology, precision instrument manufacturing and circuit board processing. According to the characteristics of nanosecond laser, this paper designs a novel nanosecond pulsed laser micromachining system with PMAC card as its core unit. The system can achieve automation control of laser parameters and movement pattern of motion system by software, which can easily realize automatic processing of point, line, and plane structure in micron scale. In this paper, several groups of experiments are taken to test the reliability and accuracy of the machining system and find the group to obtain the best processing result.

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14

Yang, Chuan Shun, and Xiang Ying Kong. "Application of Precision Time Protocol on Networked Control Systems." Applied Mechanics and Materials 203 (October 2012): 192–97. http://dx.doi.org/10.4028/www.scientific.net/amm.203.192.

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In order to overcome the problem of the clock synchronization accuracy between scattered nodes was not high on traditional networked control systems, proposed a new method of using the IEEE 1588 standard for precision time protocol. First studied the principle and algorithm of precision time protocol, the best master clock algorithm and timestamp detection methods. Then presented the timestamp detection method with the use of software and hardware on networked control systems to improve clock synchronization accuracy, and analyzed the feasibility of the method in theory. Finally, tested accuracy of the clock synchronization, and the test results showed that synchronization accuracy can reach nanosecond, can meet the application requirements of the networked control systems.

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15

Kaladchibachi, Sevag, and Fabian Fernandez. "Precision Light for the Treatment of Psychiatric Disorders." Neural Plasticity 2018 (2018): 1–16. http://dx.doi.org/10.1155/2018/5868570.

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Circadian timekeeping can be reset by brief flashes of light using stimulation protocols thousands of times shorter than those previously assumed to be necessary for traditional phototherapy. These observations point to a future where flexible architectures of nanosecond-, microsecond-, and millisecond-scale light pulses are compiled to reprogram the brain’s internal clock when it has been altered by psychiatric illness or advanced age. In the current review, we present a chronology of seminal experiments that established the synchronizing influence of light on the human circadian system and the efficacy of prolonged bright-light exposure for reducing symptoms associated with seasonal affective disorder. We conclude with a discussion of the different ways that precision flashes could be parlayed during sleep to effect neuroadaptive changes in brain function. This article is a contribution to a special issue onCircadian Rhythms in Regulation of Brain Processes and Role in Psychiatric Disorderscurated by editors Shimon Amir, Karen Gamble, Oliver Stork, and Harry Pantazopoulos.

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16

Wang, Kang, Yong Hui Hu, Zai Min He, and Hong Jiao Ma. "Design and Implementation of IEEE 1588 High Precision Clock Synchronization Based on GPS Time Service." Advanced Materials Research 532-533 (June 2012): 292–96. http://dx.doi.org/10.4028/www.scientific.net/amr.532-533.292.

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In view of PTP high precise timing requirement for many application fields, GPS time service is provided with the advantages of high precision and high stabilization. The principle and timescale of PTP based on GPS are analyzed and discussed. And then a PTP time synchronization platform with GPS-based UTC time is designed and implemented, the correlative key design flowchart is described as well. Finally, the paper gives the experiment results, which show the time synchronization accuracies can reach nanosecond range.

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17

Cao, Bao Feng, Jiang Bing Fan, Li Jun Song, Xin Li, Peng Li, Hong Wei Zhao, Qiu Han Liu, and Wang Shi Ning. "Design of a 10MPa Nanosecond Gas Switch with Adjustable Gap." Applied Mechanics and Materials 599-601 (August 2014): 643–47. http://dx.doi.org/10.4028/www.scientific.net/amm.599-601.643.

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This paper introduces a method to adjust the gap distance of nanosecond gas switch from outside when it is filled with high pressure gas. By using a two-stage planetary gear train and a pinion-and-rack device the gap between the electrodes can be linearly adjusted. The adjusting precision is 0.05 mm and adjustment range is 0 to 10 mm. The sealing of the insulator ring, rotation axle and outside conductors is designed. The performance of the rotation axle is pretty well under 12MPa gas pressure, air leakage not found. Experimental study on switch discharging is carried out by using a high voltage nanosecond pulse generator. The results show the output voltage of the pulse can reach 600kV by adjusting the switch gap. The rise-time of the pulse can be shortened form 3.5ns to 1ns.

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18

ITAMI, Shin, Mamoru HASHIMOTO, and Tsutomu ARAKI. "High Precision, White Nanosecond Xe Pulsed Light Source for High-Speed Stroboscopic Measurement." Transactions of the Japan Society of Mechanical Engineers Series C 69, no. 684 (2003): 2150–55. http://dx.doi.org/10.1299/kikaic.69.2150.

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19

Hasan, Hameedah sahib, Mohamad Shukri Zainal Abidin, and Mohd Saiful Azimi Mahmud. "UWB WITH AGV FOR LOCALIZATION SYSTEM." Science Proceedings Series 2, no. 1 (April 20, 2020): 46–49. http://dx.doi.org/10.31580/sps.v2i1.1261.

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Automated guided vehicle (AGV) has great significance in material flow and distribution of goods with high precision and efficiency. Besides, Ultra-wideband (UWB) is a technology used to transmit wireless signal in nanosecond. In this paper, localization system using AGV via UWB is designed. Futhermore, the experiment of localization with AGV is introduced and the result is disscused. In addition, control system for AGV is developed by using kinematic control system via Labview.

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20

Wang, Xulin, Jianwei Ma, Zhenyuan Jia, Chuanheng Gui, Xiaoqian Qi, and Wei Liu. "Nanosecond laser high-precision fabrication of microgrooves on TC4 surface: Morphology simulation and drag reduction performance of microgrooves." Journal of Laser Applications 34, no. 4 (November 2022): 042047. http://dx.doi.org/10.2351/7.0000745.

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With the increasing global awareness of environmental protection, higher requirements are also placed on the fuel consumption rate of aircraft. Microgrooves can reduce the near-wall frictional resistance of aircraft to save fuel, which has become the focus of research in the aviation industry. To realize the low-cost and high-precision fabrication of microgrooves with drag reduction effect, an efficient and high-precision numerical simulation method for nanosecond pulsed laser etching TC4 titanium alloy is studied. A laser processing strategy is formulated. Furthermore, an efficient and high-precision computational fluid dynamics simulation method is studied to verify the drag reduction effect of microgrooves. The research results show that the size error of prepared microgrooves is less than 2%, and their drag reduction rate is as high as 9.6%, which verifies the validity and reliability of the research method in this paper. This work can guide the design of high-density functional microstructures and their high-efficiency and high-precision fabrication. The research results can provide technical parameters for aircraft drag reduction, which has essential engineering practical value.

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21

Lei, Pengyu, Zhitian Li, Bo Xue, Haifeng Zhang, and Xudong Zou. "Hybsync: Nanosecond Wireless Position and Clock Synchronization Based on UWB Communication with Multisensors." Journal of Sensors 2021 (September 24, 2021): 1–12. http://dx.doi.org/10.1155/2021/9920567.

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PNT (positioning, navigation, and timing) is the core functional part of kinds of wireless sensor network, which can provide high-precision timing and positioning services for cooperative work systems. Unfortunately, the mature wireless PNT schemes are generally based on GNSS and other auxiliary sources to complete the high accuracy synchronization process, which cannot be applied to GNSS degraded and denied environments such as mines, underground application. In order to solve the application problem of high-precision wireless PNT, Hybsync—a novel non-GNSS-aided wireless PNT architecture, is proposed in this paper, which integrates the information from the UWB communication, inertial sensor, and camera to achieve great PNT performance. Hybsync improves the accuracy of time deviation measurement by collecting and recording timestamps in hardware layer, and with the coarse/fine synchronization two-phase calibration, Hybsync greatly improves the accuracy of time deviation adjustment, thus providing accurate time information for the whole system. Besides, Hybsync uses the VINS framework to further integrate the real-time information of IMU and camera to complete the multinode positioning service. Under the premise that the cost is much lower than existing solutions, Hybsync can provide nanosecond-level clock synchronization and centimeter-level positioning. Experiments prove that Hybsync supports high-precision clock synchronization and positioning of more than 10 nodes; the maximum clock synchronization error is 3 ns, and the positioning error is 7 cm. It can provide accurate time and position services for cooperative work systems under complex and GNSS-denied conditions.

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22

Yang, Zhanfei, Yichao Ma, Wenhui Yang, and Yiyuan Zhang. "Implementation of White Rabbit Time Synchronization System in State Acquisition System of High-energy Physics Experimental Device." Journal of Physics: Conference Series 2264, no. 1 (April 1, 2022): 012014. http://dx.doi.org/10.1088/1742-6596/2264/1/012014.

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Abstract The state acquisition system of high energy physics experimental device has very high requirements for the clock synchronization accuracy of each node. The White Rabbit (WR) distributed synchronous timing technology can realize multi node sub nanosecond clock distribution within several kilometers, and meet the requirements of clock synchronization accuracy of the system. This paper presents an implementation of WR timing system with ZYNQ 7045 as the core in the state acquisition system. This paper introduces the hardware design and implementation scheme of collector node, the implementation scheme of WR node, and the statistical data of WR-PTP time synchronization experiment results. The test results show that this method can realize the time synchronization between the nodes of the state collector, and the accuracy is better than 1 nanosecond. It can provide high-precision time synchronization function for the multi node signal acquisition system of high-energy physics experiment.

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23

Li, Zhong Yang, Zhao Yang Zhang, Yao Min Wang, and Wei Ping Mao. "Stress-Etching Using Laser Electrochemical Micromachining with Masks." Applied Mechanics and Materials 268-270 (December 2012): 468–72. http://dx.doi.org/10.4028/www.scientific.net/amm.268-270.468.

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Metal workpiece was processed by nanosecond pulsed laser electrochemical micro-etching with masks patterns in the shape of letter "E". In the experimental system established, the effect of different laser energy on processing quality was studied in air. In the different concentrations of the electrolyte, through optimized composite machining parameters, machining results of different laser energy with the masks were analyzed and compared in Aluminum alloy and Stainless steel. There was a large of difference in machining morphology by laser electrochemical micromachining with masks in two different metal materials. The results show that laser electrochemical micro-etching with masks has high efficiency and the prospects for the large-scale production, but the etching precision should be also further improved. Moreover, the nanosecond pulsed laser thermal-stress etching, electrochemical etching and the two combined coupling etching are the main factors to achieve the metal removal.

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24

Wu, Congyi, Youmin Rong, and Ranwu Yang. "Thermal ablation regulation for ultraviolet (UV) nanosecond laser precision cutting of polycarbonate (PC) film." Optics & Laser Technology 143 (November 2021): 107365. http://dx.doi.org/10.1016/j.optlastec.2021.107365.

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25

Zhu, Wang Chun, and Xin Zhang. "The Research of IEEE 1588 Interface Module Based on LXI Instrument." Advanced Materials Research 846-847 (November 2013): 848–52. http://dx.doi.org/10.4028/www.scientific.net/amr.846-847.848.

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LXI, which is generally recognized as the new generation of instrument bus technology, not only has developed rapidly in the field of test and measurement, but also has a vast potential for future development. At present, the LXI trigger requires the clock synchronization precision to reach a sub microsecond level or even higher one. Therefore, in order to meet this accuracy requirement, a scheme based on the embedded Linux and IEEE 1588 protocol is proposed in this paper on the basis of studying LXI so as to realize high accurate clock synchronization. This scheme acquires hardware timestamp by utilizing PHY chip DP83640 and realizes PTP hardware clock driving based on Linux. A synchronization test with Agilent B LXI trigger box under the current condition is conducted and about 100ns of synchronization precision can be reached when connected with cable directly. The result demonstrates the feasibility of the scheme and that the clock synchronization precision can reach a nanosecond level.

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26

Yu, Hanguang, Andrew Herschfelt, Shunyao Wu, Sharanya Srinivas, Yang Li, Nunzio Sciammetta, Leslie Smith, et al. "Communications and High-Precision Positioning (CHP2): Hardware Architecture, Implementation, and Validation." Sensors 23, no. 3 (January 25, 2023): 1343. http://dx.doi.org/10.3390/s23031343.

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Spectral congestion and modern consumer applications motivate radio technologies that efficiently cooperate with nearby users and provide several services simultaneously. We designed and implemented a joint positioning-communications system that simultaneously enables network communications, timing synchronization, and localization to a variety of airborne and ground-based platforms. This Communications and High-Precision Positioning (CHP2) system simultaneously performs communications and precise ranging (<10 cm) with a narrow band waveform (10 MHz) at a carrier frequency of 915 MHz (US ISM) or 783 MHz (EU Licensed). The ranging capability may be extended to estimate the relative position and orientation by leveraging the spatial diversity of the multiple-input, multiple-output (MIMO) platforms. CHP2 also digitally synchronizes distributed platforms with sub-nanosecond precision without support from external systems (GNSS, GPS, etc.). This performance is enabled by leveraging precise time-of-arrival (ToA) estimation techniques, a network synchronization algorithm, and the intrinsic cooperation in the joint processing chain that executes these tasks simultaneously. In this manuscript, we describe the CHP2 system architecture, hardware implementation, and in-lab and over-the-air experimental validation.

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27

Wu, Congyi, Jun Xu, Tian Zhang, Guoqiang Xin, Min Li, Youmin Rong, Guojun Zhang, and Yu Huang. "Precision cutting of PDMS film with UV-nanosecond laser based on heat generation-diffusion regulation." Optics & Laser Technology 145 (January 2022): 107462. http://dx.doi.org/10.1016/j.optlastec.2021.107462.

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28

Li, Zhi Yong, Hong Li Liu, and Zhi Peng Duan. "Process Experimental Research of Micro-Hole in Electrochemical Micromachining by Nanosecond Pulse Current." Advanced Materials Research 764 (September 2013): 15–19. http://dx.doi.org/10.4028/www.scientific.net/amr.764.15.

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Electrochemical micro-machining (ECMM) is a method that utilizes anode dissolution principle to process shaping. In the Electrochemical machining （ECM）of micro-hole, machining precision is an important aspect to measure machining quality of micro-hole. In this paper micro-hole machining is regarded as the research object, effects of many factors such as power supply natures, electrolyte composition, pulse width and pulse frequency on machining accuracy in micro-hole ECM have been evaluated. Research shows that processing accuracy can be improved through using non-linear electrolyte in high frequency, narrow pulse electrochemical machining.

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29

Shu, Xia Yun, and Hong Hai Zhang. "Design and Experimental Investigation on High Efficient Horizontal Micro Electrical Discharge Machine." Applied Mechanics and Materials 456 (October 2013): 32–37. http://dx.doi.org/10.4028/www.scientific.net/amm.456.32.

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Micro-electrical discharge machining is a non-contact manufacturing process without macroscopic force. Microelectrode fabrication is the fundamental and influence factor of micro electric discharge machining. As for the efficiency of microelectrode fabrication, this paper proposed a fast online microelectrode fabrication method by an efficient horizontal micro electric discharge machine, in which an online diamond wheel ultra-precision grinding method and an online wire electrical discharge grinding method is combined to fabricate microelectrode. Machine designed in this paper consist of a CCD online dimension examination system, precision motion and feeding system, nanosecond-pulse independent discharged power supply and gap state-detection system. experimental study on microelectrode, micro nozzle fabrication and microstructure milling by the machine conducted. Microelectrode with 15 micrometers in diameter and micro hole with 50 micrometers in diameter are done in experiment. Results show that the composite method improves the efficiency of micro electrical discharge machining.

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30

Tan, Jia Hai, Peng Yu Li, You Shan Qu, Ya Meng Han, Ya Li Yu, and Wei Wang. "Design of Calibration System for a Great Quantity of High Precision Scientific Grade CCD Cameras." Applied Mechanics and Materials 331 (July 2013): 326–30. http://dx.doi.org/10.4028/www.scientific.net/amm.331.326.

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For the calibration of a great quantity of scientific grade CCD cameras in the high energy physics system, a scientific grade CCD camera calibration system with high precision and efficiency is designed. The designed camera calibration system consists of a 1053nm nanosecond solid-state laser, a knife, a double-integrating sphere, a laser power meter, a signal generator, a computer with its data processing software. Key technical parameters of scientific grade CCD under the condition of 1053nm optical pulses that are the modulation, contrast, defects, optical dynamic range, non-linear response can be calibrated by the designed calibration system. A double-integrating sphere with high uniformity and stability is designed as a uniform light source, which improves the calibrating performance and accuracy. Experimental results show the system designed in this paper can calibrate the large number of scientific grade CCD cameras quickly and efficiently.

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31

Zhang, Hongyu, Jianke Di, Ming Zhou, and Yu Yan. "A Comparison in laser precision drilling of stainless steel 304 with nanosecond and picosecond laser pulses." Chinese Journal of Mechanical Engineering 27, no. 5 (August 23, 2014): 972–77. http://dx.doi.org/10.3901/cjme.2014.0723.125.

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32

Jin, S. G., R. Jin, and D. Li. "Assessment of BeiDou differential code bias variations from multi-GNSS network observations." Annales Geophysicae 34, no. 2 (February 18, 2016): 259–69. http://dx.doi.org/10.5194/angeo-34-259-2016.

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Abstract. The differential code bias (DCB) of global navigation satellite systems (GNSSs) affects precise ionospheric modeling and applications. In this paper, daily DCBs of the BeiDou Navigation Satellite System (BDS) are estimated and investigated from 2-year multi-GNSS network observations (2013–2014) based on global ionospheric maps (GIMs) from the Center for Orbit Determination in Europe (CODE), which are compared with Global Positioning System (GPS) results. The DCB of BDS satellites is a little less stable than GPS solutions, especially for geostationary Earth orbit (GEO) satellites. The BDS GEO observations decrease the precision of inclined geosynchronous satellite orbit (IGSO) and medium Earth orbit (MEO) DCB estimations. The RMS of BDS satellites DCB decreases to about 0.2 ns when we remove BDS GEO observations. Zero-mean condition effects are not the dominant factor for the higher RMS of BDS satellites DCB. Although there are no obvious secular variations in the DCB time series, sub-nanosecond variations are visible for both BDS and GPS satellites DCBs during 2013–2014. For satellites in the same orbital plane, their DCB variations have similar characteristics. In addition, variations in receivers DCB in the same region are found with a similar pattern between BDS and GPS. These variations in both GPS and BDS DCBs are mainly related to the estimated error from ionospheric variability, while the BDS DCB intrinsic variation is in sub-nanoseconds.

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33

Tang, Jingling, Zhenxu Bai, Duo Zhang, Yaoyao Qi, Jie Ding, Yulei Wang, and Zhiwei Lu. "Advances in All-Solid-State Passively Q-Switched Lasers Based on Cr4+:YAG Saturable Absorber." Photonics 8, no. 4 (March 27, 2021): 93. http://dx.doi.org/10.3390/photonics8040093.

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All-solid-state passively Q-switched lasers have advantages that include simple structure, high peak power, and short sub-nanosecond pulse width. Potentially, these lasers can be applied in multiple settings, such as in miniature light sources, laser medical treatment, remote sensing, and precision processing. Cr4+:YAG crystal is an ideal Q-switch material for all-solid-state passively Q-switched lasers owing to its high thermal conductivity, low saturation light intensity, and high damage threshold. This study summarizes the research progress on all-solid-state passively Q-switched lasers that use Cr4+:YAG crystal as a saturable absorber and discusses further prospects for the development and application of such lasers.

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34

Bruijn, Ronald. "The KM3NeT Digital Optical Module and Detection Unit." EPJ Web of Conferences 207 (2019): 06002. http://dx.doi.org/10.1051/epjconf/201920706002.

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The KM3NeT Collaboration is constructing new-generation neutrino detectors in the Mediterranean Sea. The main goals are the study of the highenergy neutrino flux and the determination of the neutrino mass ordering. The basic detection element, the Digital Optical Module (DOM), houses 31 3-inch PMTs inside a 17-inch glass sphere. The aim is to measure photons emitted by products of neutrino interactions in the sea-water with nanosecond precision. The multi-PMT concept has many advantages over a single-PMT design. We will discus these aspects and the enabling technologies. Additionally, the required mechanical and optical/electrical system on which DOMs are deployed as vertical strings, called Detection Units will be discussed.

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35

Coroado, Julio, Supriyo Ganguly, Wojciech Suder, Stewart Williams, Sonia Meco, and Goncalo Pardal. "Selection of parameters in nanosecond pulsed wave laser micro-welding." International Journal of Advanced Manufacturing Technology 115, no. 9-10 (May 31, 2021): 2929–44. http://dx.doi.org/10.1007/s00170-021-07251-8.

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AbstractThe digital control of the latest nanosecond pulsed wave (PW) fibre lasers allows very high flexibility in controlling the application of the total energy to a workpiece, which brings several advantages to the joining process. By choosing different pulse shapes in different spatial profiles, it is possible to apply low energy per pulse with high precision and accuracy resulting in lower heat input. Since the energy of each pulse is insufficient to generate melting, these lasers operate at very high pulse repetition frequencies near continuous wave (CW) regime. Nevertheless, the peak powers of PW lasers are much higher than CW. In this research, the effect of peak power, pulse energy, pulse width, pulse repetition frequency and duty cycle has been studied. The experimental work was conducted in bead on plate of austenitic stainless steel to investigate the effect of laser on the weld geometry, i.e. depth of penetration and width. An empirical model, previously established for CW mode, which enables the achievement of a particular penetration depth independent of the beam diameter, was redesigned and tested for PW mode. The “pulse power factor model” allows the laser user to select a weld profile that meets certain quality and productivity requirements independent of the laser system. It was shown that identical depth of penetration but different weld metal profile can be obtained for a specific beam diameter for a range of different system parameters by keeping a constant trade-off between pulse power factor and interaction time.

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36

Schaaf, Tory M., Kurt C. Peterson, Benjamin D. Grant, Prachi Bawaskar, Samantha Yuen, Ji Li, Joseph M. Muretta, Gregory D. Gillispie, and David D. Thomas. "High-Throughput Spectral and Lifetime-Based FRET Screening in Living Cells to Identify Small-Molecule Effectors of SERCA." SLAS DISCOVERY: Advancing the Science of Drug Discovery 22, no. 3 (December 13, 2016): 262–73. http://dx.doi.org/10.1177/1087057116680151.

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A robust high-throughput screening (HTS) strategy has been developed to discover small-molecule effectors targeting the sarco/endoplasmic reticulum calcium ATPase (SERCA), based on a fluorescence microplate reader that records both the nanosecond decay waveform (lifetime mode) and the complete emission spectrum (spectral mode), with high precision and speed. This spectral unmixing plate reader (SUPR) was used to screen libraries of small molecules with a fluorescence resonance energy transfer (FRET) biosensor expressed in living cells. Ligand binding was detected by FRET associated with structural rearrangements of green fluorescent protein (GFP, donor) and red fluorescent protein (RFP, acceptor) fused to the cardiac-specific SERCA2a isoform. The results demonstrate accurate quantitation of FRET along with high precision of hit identification. Fluorescence lifetime analysis resolved SERCA’s distinct structural states, providing a method to classify small-molecule chemotypes on the basis of their structural effect on the target. The spectral analysis was also applied to flag interference by fluorescent compounds. FRET hits were further evaluated for functional effects on SERCA’s ATPase activity via both a coupled-enzyme assay and a FRET-based calcium sensor. Concentration-response curves indicated excellent correlation between FRET and function. These complementary spectral and lifetime FRET detection methods offer an attractive combination of precision, speed, and resolution for HTS.

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37

Jaworski, Piotr, Fei Yu, Richard M. Carter, Jonathan C. Knight, Jonathan D. Shephard, and Duncan P. Hand. "High energy green nanosecond and picosecond pulse delivery through a negative curvature fiber for precision micro-machining." Optics Express 23, no. 7 (March 25, 2015): 8498. http://dx.doi.org/10.1364/oe.23.008498.

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38

Vainshtein, Sergey, Guoyong Duan, Timo Rahkonen, Zachary Taylor, Valery Zemlyakov, Vladimir Egorkin, Olga Smolyanskaya, Thomas Skotnicki, and Wojciech Knap. "Self-damping of the relaxation oscillations in miniature pulsed transmitter for sub-nanosecond-precision, long-distance LIDAR." Results in Physics 19 (December 2020): 103509. http://dx.doi.org/10.1016/j.rinp.2020.103509.

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39

Beagley, B., and J. R. Helliwell. "Durward W. J. Cruickshank. 7 March 1924—13 July 2007." Biographical Memoirs of Fellows of the Royal Society 65 (September 5, 2018): 71–87. http://dx.doi.org/10.1098/rsbm.2018.0018.

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Durward Cruickshank was an eminent crystallographer and structural chemist, whose mathematical abilities transformed the precision of the molecular structures determined in three dimensions by X-ray crystal structure analysis. This technique is very widely applied to determine the three-dimensional (3D) shapes of molecules of importance in biology, chemistry, mineralogy, materials science and physics. Durward's first publication was on this topic, with Sir Gordon Cox. It represents a lifelong interest of Durward in the precision of crystal structure analysis and extended also to gas-phase electron diffraction. His research publications spanned an amazing 60 years and he had a direct influence on over 900 000 chemical crystal structures, the number currently determined and held in the Cambridge Structure Database alone. Proteins took his attention for research in his last decade, and his diffraction precision index (DPI) indicator of the precision of a protein structure is added regularly to entries in the Protein Data Bank. In his ‘retirement’ he contributed, with one of the authors of this memoir, J.R.H., and various colleagues in the UK and the USA, to the development of the ‘Laue diffraction’ white beam synchrotron method, applied today to sub-nanosecond X-ray crystallography measurement techniques, and also to study micron sized, i.e. tiny, crystal samples. The method has also led ultimately to more effective exploitation of neutron beams from research reactors for crystallographic studies of the hydrogenation details of molecules.

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40

Pan, Xue, Xuechun Li, Shengjia Zhang, Jiangfeng Wang, Panzheng Zhang, Youen Jiang, Xinghua Lu, Peng Zhang, and Xiang Li. "High precision synchronization of shaped nanosecond pulse with compressible chirped short pulse used in front-end of ICF." Journal of Modern Optics 57, no. 17 (October 10, 2010): 1579–82. http://dx.doi.org/10.1080/09500340.2010.511721.

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41

Regan, P. H. "Precision measurement of sub-nanosecond lifetimes of excited nuclear states using fast-timing coincidences with LaBr3(Ce) detectors." Radiation Physics and Chemistry 116 (November 2015): 38–42. http://dx.doi.org/10.1016/j.radphyschem.2015.01.029.

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42

NAKAE, L. F., G. F. CHAPLINE, A. M. GLENN, P. L. KERR, K. S. KIM, S. A. OUEDRAOGO, M. K. PRASAD, et al. "THE USE OF FAST NEUTRON DETECTION FOR MATERIALS ACCOUNTABILITY." International Journal of Modern Physics: Conference Series 27 (January 2014): 1460140. http://dx.doi.org/10.1142/s2010194514601409.

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For many years at LLNL, we have been developing time-correlated neutron detection techniques and algorithms for applications such as Arms Control, Threat Detection and Nuclear Material Assay. Many of our techniques have been developed specifically for the relatively low efficiency (a few percent) inherent in man-portable systems. Historically, thermal neutron detectors (mainly 3 He ) were used, taking advantage of the high thermal neutron interaction cross-sections, but more recently we have been investigating the use of fast neutron detection with liquid scintillators, inorganic crystals, and in the near future, pulse-shape discriminating plastics that respond over 1000 times faster (nanoseconds versus tens of microseconds) than thermal neutron detectors. Fast neutron detection offers considerable advantages, since the inherent nanosecond production timescales of fission and neutron-induced fission are preserved and measured instead of being lost in the thermalization of thermal neutron detectors. We are now applying fast neutron technology to the safeguards regime in the form of high efficiency counters. Faster detector response times and sensitivity to neutron momentum show promise in measuring, differentiating, and assaying samples that have modest to very high count rates, as well as mixed neutron sources (e.g., Pu oxide or Mixed Cm and Pu ). Here we report on measured results with our existing liquid scintillator array and promote the design of a nuclear material assay system that incorporates fast neutron detection, including the surprising result that fast liquid scintillator becomes competitive and even surpasses the precision of 3 He counters measuring correlated pairs in modest (kg) samples of plutonium.

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43

Osterhoff, Markus, Malte Vassholz, Hannes Paul Hoeppe, Juan Manuel Rosselló, Robert Mettin, Johannes Hagemann, Johannes Möller, et al. "Nanosecond timing and synchronization scheme for holographic pump–probe studies at the MID instrument at European XFEL." Journal of Synchrotron Radiation 28, no. 3 (April 20, 2021): 987–94. http://dx.doi.org/10.1107/s1600577521003052.

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Single-pulse holographic imaging at XFEL sources with 1012 photons delivered in pulses shorter than 100 fs reveal new quantitative insights into fast phenomena. Here, a timing and synchronization scheme for stroboscopic imaging and quantitative analysis of fast phenomena on time scales (sub-ns) and length-scales (≲100 nm) inaccessible by visible light is reported. A fully electronic delay-and-trigger system has been implemented at the MID station at the European XFEL, and applied to the study of emerging laser-driven cavitation bubbles in water. Synchronization and timing precision have been characterized to be better than 1 ns.

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44

Yang, Chunmei, Ting Jiang, Yueqiang Yu, Yan Bai, Mingliang Song, Qian Miao, Yan Ma, and Jiuqing Liu. "Water-jet assisted nanosecond laser microcutting of northeast China ash wood: Experimental study." BioResources 14, no. 1 (November 13, 2018): 128–38. http://dx.doi.org/10.15376/biores.14.1.128-138.

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Laser machining is an advanced technology that provides efficiency and precision for the processing of wood. In this paper, the ablation mechanism of wood processed via a water-jet assisted nanosecond laser was analyzed. The influences of cutting speed and laser power on the cutting width of northeast China ash wood (NCAW) (Fraxinus mandshurica Rupr.) with and without the water-jet assisted system were evaluated. The surface morphology of the kerf of processed NCAW was observed via scanning electron microscopy (SEM). Furthermore, a factorial design experiment was carried out to analyze the effects of process parameters on the cutting width. Additionally, the experimental results were processed by multilinear regression analysis. The results showed that with the water-jet assisted system, the minimum value of the cutting width was 0.18 mm when the cutting speed was 50 mm/s and the laser power was 6 W, and good surface quality was obtained. The experimental results were processed by an analysis of variance and multilinear regression analysis. The predicted model, effectively validated by the experiments, had good prediction accuracy, which provided a theoretical basis for predicting the cutting width of NCAW processed by a water-jet assisted laser.

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45

Liang, Yuchen, Guang Feng, Xiaogang Li, Haoran Sun, Wei Xue, Kunpeng Zhang, and Fengping Li. "Simulation Analysis of Nanosecond Laser Processing of Titanium Alloy Based on Helical Trepanning." Applied Sciences 12, no. 18 (September 8, 2022): 9024. http://dx.doi.org/10.3390/app12189024.

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Titanium alloy is a type of high-strength material that is difficult to process. In particular, in the aerospace field, the processing accuracy of titanium alloy is high. Recently, laser processing has emerged as a new technology with high processing precision. However, the laser processing methods have obvious differences in processing accuracy and effect. Among them, the laser spiral scanning method plays an important role in welding and drilling, but owing to the complexity of the laser molten pool behavior, there have been limited studies on the material removal mechanism based on laser spiral scanning. To understand the variable process of titanium alloy melt pool in laser spiral scanning processing, a light heat conduction model with mass transfer source term was simulated. The effects of laser power, scanning speed, and scanning path on the morphology were studied. The simulation results show that the unit energy density was the main factor for material removal, and the distribution of the material temperature affected the size of the recast layer. The experimental and simulation results were compared, and good agreement between them was observed. This study can provide a research foundation for the further application of laser spiral scanning technology.

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46

Kurata, Yohei, Tomoe Tsuchida, and Satoru Tsuchikawa. "Time-of-flight Near-infrared Spectroscopy for Nondestructive Measurement of Internal Quality in Grapefruit." Journal of the American Society for Horticultural Science 138, no. 3 (May 2013): 225–28. http://dx.doi.org/10.21273/jashs.138.3.225.

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We proposed a technique combining time-of-flight (TOF) and near-infrared spectroscopy (NIRS), termed TOF-NIRS, capable of measuring the time-resolved profiles of near-infrared (NIR) light with nanosecond resolution. Analysis of the variation in time-resolved profiles was used to estimate soluble solids concentration (SSC) and acidity in grapefruit (Citrus paradisi), and the prediction accuracy was compared with the conventional NIR measurement device. In data processing, the cross-correlation function, which evaluated the similarity between the reference and transmitted beams, was introduced as an explanatory variable for partial least squares regression. TOF-NIRS predicted both SSC and acidity in grapefruit with higher precision than the conventional NIR measurement with respective r values of 0.72 and 0.85. Specifically, the superiority of TOF-NIRS was attributed to measurement time and prediction accuracy in determining acidity.

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47

Staehr, R., S. Bastick, S. Bluemel, P. Jaeschke, O. Suttmann, J. P. Negel, V. Angrick, C. Stolzenburg, S. Kaierle, and L. Overmeyer. "High precision laser macrodrilling of carbon fiber reinforced plastics with a new nanosecond pulsed laser—Optimized toward industrial needs." Journal of Laser Applications 31, no. 2 (May 2019): 022207. http://dx.doi.org/10.2351/1.5096120.

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48

Rong, Youmin, Lu Wang, Tian Zhang, Min Li, Yu Huang, Guojun Zhang, and Congyi Wu. "Precision cutting of epoxy resin board (ERB) by ultraviolet (UV) nanosecond laser ablation with consideration of hazardous gas protection." Optik 241 (September 2021): 167154. http://dx.doi.org/10.1016/j.ijleo.2021.167154.

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49

Schaaf, Tory, Ang Li, Benjamin Grant, Kurt Peterson, Samantha Yuen, Prachi Bawaskar, Evan Kleinboehl, Ji Li, David Thomas, and Gregory Gillispie. "Red-Shifted FRET Biosensors for High-Throughput Fluorescence Lifetime Screening." Biosensors 8, no. 4 (October 24, 2018): 99. http://dx.doi.org/10.3390/bios8040099.

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We have developed fluorescence resonance energy transfer (FRET) biosensors with red-shifted fluorescent proteins (FP), yielding improved characteristics for time-resolved (lifetime) fluorescence measurements. In comparison to biosensors with green and red FRET pairs (GFP/RFP), FPs that emit at longer wavelengths (orange and maroon, OFP/MFP) increased the FRET efficiency, dynamic range, and signal-to-background of high-throughput screening (HTS). OFP and MFP were fused to specific sites on the human cardiac calcium pump (SERCA2a) for detection of structural changes due to small-molecule effectors. When coupled with a recently improved HTS fluorescence lifetime microplate reader, this red-shifted FRET biosensor enabled high-precision nanosecond-resolved fluorescence decay measurements from microliter sample volumes at three minute read times per 1536-well-plate. Pilot screens with a library of small-molecules demonstrate that the OFP/MFP FRET sensor substantially improves HTS assay quality. These high-content FRET methods detect minute FRET changes with high precision, as needed to elucidate novel structural mechanisms from small-molecule or peptide regulators discovered through our ongoing HTS efforts. FRET sensors that emit at longer wavelengths are highly attractive to the FRET biosensor community for drug discovery and structural interrogation of new therapeutic targets.

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50

Diez-Cabanes, Valentin, Giacomo Prampolini, Antonio Francés-Monerris, Antonio Monari, and Mariachiara Pastore. "Iron’s Wake: The Performance of Quantum Mechanical-Derived Versus General-Purpose Force Fields Tested on a Luminescent Iron Complex." Molecules 25, no. 13 (July 6, 2020): 3084. http://dx.doi.org/10.3390/molecules25133084.

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Recently synthetized iron complexes have achieved long-lived excited states and stabilities which are comparable, or even superior, to their ruthenium analogues, thus representing an eco-friendly and cheaper alternative to those materials based on rare metals. Most of computational tools which could help unravel the origin of this large efficiency rely on ab-initio methods which are not able, however, to capture the nanosecond time scale underlying these photophysical processes and the influence of their realistic environment. Therefore, it exists an urgent need of developing new low-cost, but still accurate enough, computational methodologies capable to deal with the steady-state and transient spectroscopy of transition metal complexes in solution. Following this idea, here we focus on the comparison between general-purpose transferable force-fields (FFs), directly available from existing databases, and specific quantum mechanical derived FFs (QMD-FFs), obtained in this work through the Joyce procedure. We have chosen a recently reported FeIII complex with nanosecond excited-state lifetime as a representative case. Our molecular dynamics (MD) simulations demonstrated that the QMD-FF nicely reproduces the structure and the dynamics of the complex and its chemical environment within the same precision as higher cost QM methods, whereas general-purpose FFs failed in this purpose. Although in this particular case the chemical environment plays a minor role on the photo physics of this system, these results highlight the potential of QMD-FFs to rationalize photophysical phenomena provided an accurate QM method to derive its parameters is chosen.

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