Articles de revues : « Helium3 »

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SIRGHI, D. L., M. BAZZI, G. BEER, L. BOMBELLI, A. M. BRAGADIREANU, M. CARGNELLI, G. CORRADI et al. « KAONIC HELIUM MEASUREMENTS IN THE SIDDHARTA EXPERIMENT ». International Journal of Modern Physics A 26, n^o 03n04 (10 février 2011) : 601–3. http://dx.doi.org/10.1142/s0217751x11052165.

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The SIDDHARTA experiment (SIlicon Drift Detector for Hadronic Atom Research by Timing Application) had the aim to perform kaonic atoms X-ray transitions measurements, to better understand aspects of the low-energy QCD in the strangeness sector. The experiment combined the excellent low-energy kaon beam generated at DAΦNE, allowing to use gaseous targets, with excellent fast X-rays detectors: Silicon Drift Detectors. SIDDHARTA was installed on DAΦNE in autumn 2008 and took data till late 2009. Apart of the kaonic hydrogen and kaonic deuterium measurements, we have performed the kaonic helium transitions to the 2p level ( L -lines) measurements: for the first time in a gaseous target for helium4 and for the first time ever for kaonic helium3. The interest for such type of measurement was rather high, being it triggered by two reasons: the so-called "kaonic helium puzzle" (even if this was solved by KEK-PS E570 experiment, but a cross-check was useful) and some theoretical predictions of possible high energy shift (at the level of 10 eV). In this paper the preliminary results for the measurements to the 2p level ( L -series) for kaonic helium4 and kaonic helium3 are presented.

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Callot, V., E. Canet, J. Brochot, H. Humblot, A. Briguet, H. Tournier et Y. Crémillieux. « Hyperpolarized Helium3 Encapsulated in Microbubbles ». Academic Radiology 9, n^o 2 (février 2002) : S501—S503. http://dx.doi.org/10.1016/s1076-6332(03)80276-3.

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Kempiński, Wojciech, Szymon Łoś, Zbigniew Trybuła, Maciej Chorowski, Jarosław Poliński, Jakub Niechciał, Tomasz Jaskólski, Katarzyna Chołast et Andrzej Kociemba. « Helium3 isotope separation and lambda front observation ». Separation and Purification Technology 210 (février 2019) : 276–80. http://dx.doi.org/10.1016/j.seppur.2018.08.003.

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Nazirzadeh, M., B. Khanbabaei et A. Ghasemizad. « The investigation of inertial fusion burning requirements of deuterium-helium3 in degenerate plasma ». Physics of Plasmas 24, n^o 8 (août 2017) : 082708. http://dx.doi.org/10.1063/1.5000068.

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Tahir, N. A., et D. H. H. Hoffmann. « Development of advanced fuel inertial fusion targets ». Laser and Particle Beams 15, n^o 4 (décembre 1997) : 575–87. http://dx.doi.org/10.1017/s0263034600011150.

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This paper discusses the implications of using different fuels, including pure deuterium, deuterium–tritium, deuterium–helium3, and proton–boron11, on safety and environmental compatibility of the fusion reactor, as well as on the driver requirements. Due to present-day technology limitations, it seems likely that the first generation of the fusion reactors will be based on a deuterium–tritium cycle. Such a scheme, however, would pose serious problems, including neutron activation and tritium handling. We show that by developing low-level tritium inertial fusion targets, one may substantially reduce the daily use of tritium in the reactor that may ultimately lead to a reduction in the overall tritium inventory in the power plant. Such reduced tritium targets will still generate sufficient energy to run the power plant economically.

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Stupar, Vasile, Yves Berthezène, Emmanuelle Canet, Hervé Tournier, David Dupuich et Yannick Crémillieux. « Helium3 Polarization Using Spin Exchange Technique : Application to Simultaneous Pulmonary Ventilation/Perfusion Imaging in Small Animals ». Investigative Radiology 38, n^o 6 (juin 2003) : 334–40. http://dx.doi.org/10.1097/01.rli.0000066250.86614.32.

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Peterson, Marina. « Moving Between ». liquid blackness 5, n^o 1 (1 avril 2021) : 119–25. http://dx.doi.org/10.1215/26923874-8932635.

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Abstract Helium's material form is unstable, moving from gas to liquid under temperature. Lighter than air, it evades the immediacy of perception. Thinking through helium offers an approach to the entanglement of forms of matter that makes movement the locus. Helium shifts an understanding of “between” to one of motion, of phase shifts and plasticity rather than difference, in which the durability of matter—and of the human—withdraws.

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Oks, Eugene. « Classical Dynamics of Rydberg States of Muonic-Electronic Helium and Helium-Like Ions in a Weak Electric Field : Counter-Intuitive Linear Stark Effect ». Dynamics 1, n^o 1 (23 mars 2021) : 1–8. http://dx.doi.org/10.3390/dynamics1010001.

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According to the existing paradigm, helium atoms and helium-like ions (hereafter, heliumic systems) in a relatively weak external static electric field do not exhibit the linear Stark effect—in distinction to hydrogen atoms and hydrogen-like ions. In the present paper we consider the classical dynamics of a muonic-electronic heliumic system in Rydberg states–starting from the concept from our previous paper. We show that there are two states of the system where the averaged electric dipole moment is non-zero. Consequently, in these states the heliumic system should exhibit the linear Stark effect even in a vanishingly small electric field, which is a counter-intuitive result. We also demonstrate the possibility of controlling the overall precession of the electronic orbit by an external electric field. In particular, we show the existence of a critical value of the external electric field that would “kill” the precession and make the electronic orbit stationary. This is another counter-intuitive result. We calculate analytically the value of the critical field and show that it is typically smaller or even much smaller than 1 V/cm.

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Yuan, Da Qing, Hai Liang Ma, Ping Fan, Yong Nan Zheng, Yi Zuo, Qiao Li Zhang, Ali Wen et al. « Synergistic Effect on Formation of Radiation Damage in CLAM Steel Studied by Triple Beam Irradiation ». Defect and Diffusion Forum 373 (mars 2017) : 117–21. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.117.

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The synergistic effect associated with displacement damage, hydrogen and heliumin the China Low Activation Martensitic (CLAM) steel has been investigated using the triple ion beamirradiation. Triple ion beams, an iron beam of 109 MeV degraded by a tantalum foil of 7.45 μm thick, the100 keV hydrogen and 200 keV helium, were injected into the CLAM steel samples simultaneously or sequentially.The radiation damage examinations were carried out by the slow positron Doppler broadening technique. Themeasured S parameters indicate that the radiation damage is different for different irradiationprocedures with same dpa and concentrations of H and He. The sample suffers most severe damage in the simultaneoustriple beam irradiation. The present experimental results support the molecular dynamics simulation result that the H facilitates the He-bubble nucleation and growth.

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Sarancha, G. А., A. S. Drozd, I. A. Emekeev, S. А. Ganin, D. Kropackova, I. S. Kudashev, V. V. Kulagin et al. « HYDROGEN AND HELIUM DISCHARGES IN THE GOLEM TOKAMAK ». Problems of Atomic Science and Technology, Ser. Thermonuclear Fusion 44, n^o 4 (2021) : 92–110. http://dx.doi.org/10.21517/0202-3822-2021-44-4-92-110.

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Aznabayev, D. T., A. K. Bekbaev, I. S. Ishmukhamedov, V. I. Korobov et A. B. Turmaganbet. « Nonrelativistic ionization energy levels of a helium atom ». Physical Sciences and Technology 2, n^o 1 (2015) : 59–65. http://dx.doi.org/10.26577/2409-6121-2015-2-1-59-65.

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Abdulrahman, Parekhan M. « A Parametric Comparison Between the Behavior 1S0 and 3S1 of Helium and the Excited S-Stated of Neon in Helium Neon Laser ». Journal of Zankoy Sulaimani - Part A 6, n^o 1 (22 décembre 2002) : 17–23. http://dx.doi.org/10.17656/jzs.10108.

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Rose-Innes, Arthur. « Helium ? What helium ? » Physics World 23, n^o 08 (août 2010) : 21. http://dx.doi.org/10.1088/2058-7058/23/08/32.

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Simmons, R. O. « Single-particle dynamics of the solid heliums from deep inelastic neutron scattering ». Canadian Journal of Physics 65, n^o 11 (1 novembre 1987) : 1401–8. http://dx.doi.org/10.1139/p87-220.

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Previous neutron-scattering research on solid heliums has been restricted to small momentum transfers, Q, both by large Debye–Waller factors and by scientific interest being restricted to collective modes and their interactions. It has also been limited by insufficient sources of neutron beams of about an electronvolt in energy, which are required to apply the method of deep inelastic scattering to solids. Making use of a spallation neutron source and a suitable chopper spectrometer, one can now collect data in which the dynamic structure factor S(Q,E) directly reflects the atomic-momentum distribution n(p). For 4He, the major determining factor on this single-particle property is the density of the sample, not its microscopic structure. At a strictly constant number density, samples of hexagonal close-packed (hcp), body-centered cubic (bcc), and normal liquid show identical S(Q,E)'s for Q's near 200 nm−1, at current levels of precision. The case of bcc 4He is used to illustrate the method, and the derived kinetic energy is compared with theoretical predictions. The applicability of these results in other areas of solid-helium physics is indicated.

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Wang, Dahai, Jinbu Li, Zhanhai Yu, Ji Zhang, Lili Liu, Feng Xiao et Changan Shan. « The Resource Potential and Development Prospect of Helium in Changqing Gas Field ». Geofluids 2022 (23 juillet 2022) : 1–11. http://dx.doi.org/10.1155/2022/9094667.

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Helium, a rare gas widely applied in high-tech fields, is a significant strategic resource in China. The foreign-trade dependence ratio of helium in China is 95%. The work reviewed the applications and market analysis of helium and reservoir modeling and distribution of helium in Changqing Gas Field as well as the helium extraction techniques from natural gases. According to the analysis of the component test and the dynamic monitoring of exploited gas wells and gas-gathering stations, the average helium content in Changqing Gas Field was 0.028%. Helium was rich in the northwest of Changqing Gas Field, but poor in the central and eastern regions. The helium volume contents in Qingyang Gas Field, Huanglong Gas Field, and the central, western, and southern regions of Sulige Gas Field have reached the industrial development standard. PetroChina performed the economic-feasibility evaluation and production-factor matching research on helium development and selected Changqing Gas Field as the demonstration for development. A large helium plant was established in Changqing Gas Field using the cryogenic method with/without membrane separation for helium extraction. Then, a helium development scheme was formulated and implemented to build the industry chain of helium in China. Changqing Gas Field is rich in helium resources. Developing helium has entered a strategic period with the technological advancement in extracting helium from natural gases and the increased prosperity of the international helium market. There are broad prospects and great benefits to exploiting helium resources in Changqing.

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Yin, Wen, Xue Jun Jia et Quan Ji. « Ab Initio Study of Helium in Tantalum : Interaction, Migration, and Clustering with Helium and Vacancies ». Materials Science Forum 1024 (mars 2021) : 121–26. http://dx.doi.org/10.4028/www.scientific.net/msf.1024.121.

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Ab initio calculations based on the Density Function Theory (DFT) have been performed to study the interaction between helium and helium, helium and vacancy, migration of helium, and the stability of small helium-vacancy clusters in tantalum. The following results are found: (I) The tetrahedral interstitial helium atoms have weak interactions in tantalum, suggesting that no stable covalent bond is formed between this two helium atoms; (II) The stability of small helium-vacancy clusters is investigated. The interstitial helium atom and vacancy to the clusters are found to be positive in almost all case, i.e., all interactions are attractive; (III) The activation energies for a substitutional helium atom migration by the dissociation or vacancy mechanisms are estimated under the irradiation condition.

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Al Rabadi, Said. « A generic concept for Helium purification and liquefaction plant ». Volume 2 issue 1 2, n^o 1 (1 août 2019) : 51–58. http://dx.doi.org/10.48103/jjeci272019.

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This study describes and evaluates the performance of producing a pure Helium fraction from Helium extraction facility designed for cryogenic natural gas plants. A generic concept for obtaining a Helium pure fraction, which has relatively lower capital and operating costs should be provided. In order to achieve this objective, a new concept for obtaining a Helium pure fraction from a crude Helium fraction, is proposed based on simulations run under diverse process conditions regarding crude Helium gas’ temperature, pressure and composition. This concept is characterized by; reducing the plant safety requirements due to the extensive separation of combustible components, and compact layout of Helium extraction plant. Further re-purification is included in the subsequent Helium liquefaction step through selective adsorption, hence then increasing the purity of the Helium product and reducing the plant energy consumption required for liquefying Helium-rich fraction and the valuable Helium boil-off routed from the storage facility. The Nitrogen-rich fraction is routed to Nitrogen liquefaction installation. Liquid Nitrogen is generated within Helium recovery facility for liquid Helium shielding and container cooling. Surplus gaseous Nitrogen either can be liquefied and used within cryogenic natural gas plant as process coolant or be vented to atmosphere.

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Helgaker, Trygve, et Wim Klopper. « Perspective on "Neue Berechnung der Energie des Heliums im Grundzustande, sowie des tiefsten Terms von Ortho-Helium" ». Theoretical Chemistry Accounts : Theory, Computation, and Modeling (Theoretica Chimica Acta) 103, n^o 3-4 (9 février 2000) : 180–81. http://dx.doi.org/10.1007/s002149900051.

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Song, Hongqing, Jie Zhang, Yueqiang Sun, Yongping Li, Xianguo Zhang, Dongyu Ma et Jue Kou. « Theoretical Study on Thermal Release of Helium-3 in Lunar Ilmenite ». Minerals 11, n^o 3 (19 mars 2021) : 319. http://dx.doi.org/10.3390/min11030319.

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The in-situ utilization of lunar helium-3 resource is crucial to manned lunar landings and lunar base construction. Ilmenite was selected as the representative mineral which preserves most of the helium-3 in lunar soil. The implantation of helium-3 ions into ilmenite was simulated to figure out the concentration profile of helium-3 trapped in lunar ilmenite. Based on the obtained concentration profile, the thermal release model for molecular dynamics was established to investigate the diffusion and release of helium-3 in ilmenite. The optimal heating temperature, the diffusion coefficient, and the release rate of helium-3 were analyzed. The heating time of helium-3 in lunar ilmenite under actual lunar conditions was also studied using similitude analysis. The results show that after the implantation of helium-3 into lunar ilmenite, it is mainly trapped in vacancies and interstitials of ilmenite crystal and the corresponding concentration profile follows a Gaussian distribution. As the heating temperature rises, the cumulative amounts of released helium-3 increase rapidly at first and then tend to stabilize. The optimal heating temperature of helium-3 is about 1000 K and the corresponding cumulative release amount is about 74%. The diffusion coefficient and activation energy of helium-3 increase with the temperature. When the energy of helium-3 is higher than the binding energy of the ilmenite lattice, the helium-3 is released rapidly on the microscale. Furthermore, when the heating temperature increases, the heating time for thermal release of helium-3 under actual lunar conditions decreases. For the optimal heating temperature of 1000 K, the thermal release time of helium-3 is about 1 s. The research could provide a theoretical basis for in-situ helium-3 resources utilization on the moon.

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Hayano, R. S. « Antiprotonic helium and kaonic helium – A tale of two exotic helium atomsThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008. » Canadian Journal of Physics 87, n^o 7 (juillet 2009) : 835–42. http://dx.doi.org/10.1139/p08-111.

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Recent progress on the precision laser spectroscopy of antiprotonic helium atoms, as well as on the X-ray spectroscopy of kaonic helium atoms, are presented. These two may appear to be unrelated topics (except that both involve exotic helium atoms), but in fact a past study of kaonic helium system led to the serendipitous discovery of antiprotonic helium. Some historical background connecting these two exotic helium atoms, as well as future prospects, are discussed.

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Hayano, R. S. « EXOTIC HELIUM ATOMS ». International Journal of Modern Physics E 19, n^o 12 (décembre 2010) : 2586–93. http://dx.doi.org/10.1142/s0218301310017125.

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Recent progress on the precision laser spectroscopy of antiprotonic helium atoms, as well as on the x-ray spectroscopy of kaonic helium atoms are presented. These two may appear to be unrelated topics (except for the fact that both being exotic helium atoms), but in fact a past study of kaonic helium system led to the serendipitous discovery of antiprotonic helium. Some historical background connecting these two exotic helium atoms, as well as future prospects are discussed.

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NEMCHENKO, K., et S. ROGOVA. « RESONANCES IN SYSTEMS WITH TWO DIFFERENT TYPES OF HEAT TRANSFER ». Modern Physics Letters B 26, n^o 23 (13 août 2012) : 1230015. http://dx.doi.org/10.1142/s0217984912300153.

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Heat transfer in double-layer systems with superfluid helium as one of the layers is studied in this paper. Double-layer systems like heater-helium and helium-detector were considered. The limiting cases of the relation of the non-helium layer length and the length of the heat wave in it were investigated. The unusual resonances were found in the double-layer system helium-detector. Analytical expressions for width and amplitudes of these resonances were obtained. At the same time it was found that the resonance width in helium can be determined not by the dissipative properties of helium, but by the thermodynamic parameters of the detector.

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Taylor, Caitlin A., Eric Lang, Paul G. Kotula, Ronald Goeke, Clark S. Snow, Yongqiang Wang et Khalid Hattar. « Helium Bubbles and Blistering in a Nanolayered Metal/Hydride Composite ». Materials 14, n^o 18 (18 septembre 2021) : 5393. http://dx.doi.org/10.3390/ma14185393.

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Helium is insoluble in most metals and precipitates out to form nanoscale bubbles when the concentration is greater than 1 at.%, which can alter the material properties. Introducing controlled defects such as multilayer interfaces may offer some level of helium bubble management. This study investigates the effects of multilayered composites on helium behavior in ion-implanted, multilayered ErD2/Mo thin film composites. Following in-situ and ex-situ helium implantation, scanning and transmission electron microscopy showed the development of spherical helium bubbles within the matrix, but primarily at the layer interfaces. Bubble linkage and surface blistering is observed after high fluence ex-situ helium implantation. These results show the ability of metallic multilayers to alter helium bubble distributions even in the presence of a hydride layer, increasing the lifetime of materials in helium environments.

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Nandipati, Giridhar, Karl D. Hammond, Dimitrios Maroudas, Kenneth J. Roche, Richard J. Kurtz, Brian D. Wirth et Wahyu Setyawan. « Effect of helium flux on near-surface helium accumulation in plasma-exposed tungsten ». Journal of Physics : Condensed Matter 34, n^o 3 (5 novembre 2021) : 035701. http://dx.doi.org/10.1088/1361-648x/ac2ca7.

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Abstract We report results of object kinetic Monte Carlo (OKMC) simulations to understand the effect of helium flux on the near-surface helium accumulation in plasma-facing tungsten, which is initially pristine, defect-free, and has a (100) surface orientation. These OKMC simulations are performed at 933 K for fluxes ranging from 1022 to 4 × 1025 He/m2 s with 100 eV helium atoms impinging on a (100) surface up to a maximum fluence of 4 × 1019 He/m2. In the near-surface region, helium clusters interact elastically with the free surface. The interaction is attractive and results in the drift of mobile helium clusters towards the surface as well as increased trap mutation rates. The associated kinetics and energetics of the above-mentioned processes obtained from molecular dynamics simulations are also considered. The OKMC simulations indicate that in pristine tungsten, as the flux decreases, the retention of implanted helium decreases, and its depth distribution shifts to deeper below the surface. Furthermore, the fraction of retained helium diffusing into the bulk increases as well, so much so that for the flux of 1022 He/m2 s, almost all of the retained helium diffused into the bulk with minimal/negligible near-surface helium accumulation. At a given flux, with increasing fluence, the fraction of retained helium initially decreases and then starts to increase after reaching a minimum. The occurrence of the retention minimum shifts to higher fluences as the flux decreases. Although the near-surface helium accumulation spreads deeper into the material with decreasing flux and increasing fluence, the spread appears to saturate at depths between 80 and 100 nm. We present a detailed analysis of the influence of helium flux on the size and depth distribution of total helium and helium bubbles.

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Nandipati, Giridhar, Karl D. Hammond, Dimitrios Maroudas, Kenneth J. Roche, Richard J. Kurtz, Brian D. Wirth et Wahyu Setyawan. « Effect of helium flux on near-surface helium accumulation in plasma-exposed tungsten ». Journal of Physics : Condensed Matter 34, n^o 3 (5 novembre 2021) : 035701. http://dx.doi.org/10.1088/1361-648x/ac2ca7.

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Abstract We report results of object kinetic Monte Carlo (OKMC) simulations to understand the effect of helium flux on the near-surface helium accumulation in plasma-facing tungsten, which is initially pristine, defect-free, and has a (100) surface orientation. These OKMC simulations are performed at 933 K for fluxes ranging from 1022 to 4 × 1025 He/m2 s with 100 eV helium atoms impinging on a (100) surface up to a maximum fluence of 4 × 1019 He/m2. In the near-surface region, helium clusters interact elastically with the free surface. The interaction is attractive and results in the drift of mobile helium clusters towards the surface as well as increased trap mutation rates. The associated kinetics and energetics of the above-mentioned processes obtained from molecular dynamics simulations are also considered. The OKMC simulations indicate that in pristine tungsten, as the flux decreases, the retention of implanted helium decreases, and its depth distribution shifts to deeper below the surface. Furthermore, the fraction of retained helium diffusing into the bulk increases as well, so much so that for the flux of 1022 He/m2 s, almost all of the retained helium diffused into the bulk with minimal/negligible near-surface helium accumulation. At a given flux, with increasing fluence, the fraction of retained helium initially decreases and then starts to increase after reaching a minimum. The occurrence of the retention minimum shifts to higher fluences as the flux decreases. Although the near-surface helium accumulation spreads deeper into the material with decreasing flux and increasing fluence, the spread appears to saturate at depths between 80 and 100 nm. We present a detailed analysis of the influence of helium flux on the size and depth distribution of total helium and helium bubbles.

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Fidelis, Wopara Onuoha, Nnadikwe Johnson, Ewelike Asterius Dozie et Udechukwu Mathew Chidubem. « Dynamic Design Evaluation of Helium Recovery and the Thermodynamics and Economics Utilization of Improved Project Viability from Sales Gas ». International Journal for Research in Applied Science and Engineering Technology 10, n^o 9 (30 septembre 2022) : 413–20. http://dx.doi.org/10.22214/ijraset.2022.46551.

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Abstract: Sales gas generally contains barely 0.05 percent helium, making recovery uneconomical. Currently available commercial helium sources range from 0.3 to 8% helium from natural gas reserves, with 0.3 percent being the economic recovery limit. This article compares the technical and economic viability of manufacturing Grade-A liquefied helium from sales gas with low helium contents utilizing combined NGL/NRU/HRU technology.

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Yu, Jinlong, Xianfei Zhang et Guoliang Lü. « Post-merger evolution of double helium white dwarfs and distribution of helium-rich hot subdwarfs ». Monthly Notices of the Royal Astronomical Society 504, n^o 2 (1 mai 2021) : 2670–74. http://dx.doi.org/10.1093/mnras/stab1063.

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ABSTRACT The mergers of double helium white dwarfs are believed to form isolated helium-rich hot subdwarfs. Observations show that helium-rich hot subdwarfs can be divided into two subgroups based on whether the surface is carbon-rich or carbon-normal. However, it is not clear whether this distribution directly comes from binary evolution. We adopt the binary population synthesis to obtain the population of single helium-rich hot subdwarfs according to the merger channel of double helium white dwarfs. We find that the merger channel can represent the two subgroups in the Teff−log g plane related to different masses of progenitor helium white dwarfs. For Z = 0.02, the birth rate and local density of helium-rich hot subdwarf stars from the merger of two helium white dwarfs are $\sim 4.82 \times 10^{-3}\, \rm yr^{-1}$ and ∼ 290.0 $\rm kpc^{-3}$ at 13.7 Gyr in our Galaxy, respectively. The proportions of carbon-rich and carbon-normal helium-rich hot subdwarfs are 32 per cent and 68 per cent, respectively.

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Boreham, Christopher J., Dianne S. Edwards, Robert J. Poreda, Thomas H. Darrah, Ron Zhu, Emmanuelle Grosjean, Philip Main, Kathryn Waltenberg et Paul A. Henson. « Helium in the Australian liquefied natural gas economy ». APPEA Journal 58, n^o 1 (2018) : 209. http://dx.doi.org/10.1071/aj17049.

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Australia is about to become the premier global exporter of liquefied natural gas (LNG), bringing increased opportunities for helium extraction. Processing of natural gas to LNG necessitates the exclusion and disposal of non-hydrocarbon components, principally carbon dioxide and nitrogen. Minor to trace hydrogen, helium and higher noble gases in the LNG feed-in gas become concentrated with nitrogen in the non-condensable LNG tail gas. Helium is commercially extracted worldwide from this LNG tail gas. Australia has one helium plant in Darwin where gas (containing 0.1% He) from the Bayu-Undan accumulation in the Bonaparte Basin is processed for LNG and the tail gas, enriched in helium (3%), is the feedstock for helium extraction. With current and proposed LNG facilities across Australia, it is timely to determine whether the development of other accumulations offers similar potential. Geoscience Australia has obtained helium contents in ~800 Australian natural gases covering all hydrocarbon-producing sedimentary basins. Additionally, the origin of helium has been investigated using the integration of helium, neon and argon isotopes, as well as the stable carbon (13C/12C) isotopes of carbon dioxide and hydrocarbon gases and isotopes (15N/14N) of nitrogen. With no apparent loss of helium and nitrogen throughout the LNG industrial process, together with the estimated remaining resources of gas accumulations, a helium volumetric seriatim results in the Greater Sunrise (Bonaparte Basin) > Ichthys (Browse Basin) > Goodwyn–North Rankin (Northern Carnarvon Basin) accumulations having considerably more untapped economic value in helium extraction than the commercial Bayu-Undan LNG development.

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Zhao, Zhou, Qiusheng Liu et Katsuya Fukuda. « Transient Heat Transfer for Helium Gas Flowing over a Plate ». Marine Engineering 48, n^o 3 (2013) : 403–8. http://dx.doi.org/10.5988/jime.48.403.

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Kunakov, S. K., E. E. Son, Zh Bolatov et M. Kaster. « Optical spectra in helium plasma generated by nuclear fission fragments ». International Journal of Mathematics and Physics 6, n^o 1 (2015) : 75–81. http://dx.doi.org/10.26577/2218-7987-2015-6-1-75-81.

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Gunnell, David, Jane Derges, Shu-Sen Chang et Lucy Biddle. « Searching for Suicide Methods ». Crisis 36, n^o 5 (septembre 2015) : 325–31. http://dx.doi.org/10.1027/0227-5910/a000326.

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Abstract. Background: Helium gas suicides have increased in England and Wales; easy-to-access descriptions of this method on the Internet may have contributed to this rise. Aims: To investigate the availability of information on using helium as a method of suicide and trends in searching about this method on the Internet. Method: We analyzed trends in (a) Google searching (2004–2014) and (b) hits on a Wikipedia article describing helium as a method of suicide (2013–2014). We also investigated the extent to which helium was described as a method of suicide on web pages and discussion forums identified via Google. Results: We found no evidence of rises in Internet searching about suicide using helium. News stories about helium suicides were associated with increased search activity. The Wikipedia article may have been temporarily altered to increase awareness of suicide using helium around the time of a celebrity suicide. Approximately one third of the links retrieved using Google searches for suicide methods mentioned helium. Conclusion: Information about helium as a suicide method is readily available on the Internet; the Wikipedia article describing its use was highly accessed following celebrity suicides. Availability of online information about this method may contribute to rises in helium suicides.

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Ayache, M., J. C. Dutay, P. Jean-Baptiste et E. Fourré. « Simulation of the mantle and crustal helium isotope signature in the Mediterranean Sea using a high-resolution regional circulation model ». Ocean Science 11, n^o 6 (21 décembre 2015) : 965–78. http://dx.doi.org/10.5194/os-11-965-2015.

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Abstract. Helium isotopes (3He, 4He) are useful tracers for investigating the deep ocean circulation and for evaluating ocean general circulation models, because helium is a stable and conservative nuclide that does not take part in any chemical or biological process. Helium in the ocean originates from three different sources, namely, (i) gas dissolution in equilibrium with atmospheric helium, (ii) helium-3 addition by radioactive decay of tritium (called tritiugenic helium), and (iii) injection of terrigenic helium-3 and helium-4 by the submarine volcanic activity which occurs mainly at plate boundaries, and also addition of (mainly) helium-4 from the crust and sedimentary cover by α-decay of uranium and thorium contained in various minerals. We present the first simulation of the terrigenic helium isotope distribution in the whole Mediterranean Sea using a high-resolution model (NEMO-MED12). For this simulation we build a simple source function for terrigenic helium isotopes based on published estimates of terrestrial helium fluxes. We estimate a hydrothermal flux of 3.5 mol3 He yr−1 and a lower limit for the crustal flux at 1.6 × 10−7 4He mol m−2 yr−1. In addition to providing constraints on helium isotope degassing fluxes in the Mediterranean, our simulations provide information on the ventilation of the deep Mediterranean waters which is useful for assessing NEMO-MED12 performance. This study is part of the work carried out to assess the robustness of the NEMO-MED12 model, which will be used to study the evolution of the climate and its effect on the biogeochemical cycles in the Mediterranean Sea, and to improve our ability to predict the future evolution of the Mediterranean Sea under the increasing anthropogenic pressure.

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Ayache, M., J. C. Dutay, P. Jean-Baptiste et P. E. Fourré. « Simulation of the mantle and crustal helium isotope signature in the Mediterranean Sea using a high-resolution regional circulation model ». Ocean Science Discussions 12, n^o 4 (25 août 2015) : 2007–41. http://dx.doi.org/10.5194/osd-12-2007-2015.

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Abstract. Helium isotopes (3He, 4He) are useful tracers for investigating the deep ocean circulation and for evaluating ocean general circulation models, because helium is a stable and conservative nuclide that does not take part in any chemical or biological process. Helium in the ocean originates from three different sources: namely, (i) gas dissolution in equilibrium with atmospheric helium, (ii) helium-3 addition by radioactive decay of tritium (called tritiugenic helium), and (iii) injection of terrigenic helium-3 and helium-4 by the submarine volcanic activity which occurs mainly at plate boundaries, and also addition of (mainly) helium-4 from the crust and sedimentary cover by α-decay of uranium and thorium contained in various minerals. We present the first simulation of the terrigenic helium isotope distribution in the whole Mediterranean Sea, using a high-resolution model (NEMO-MED12). For this simulation we build a simple source function for terrigenic helium isotopes based on published estimates of terrestrial helium fluxes. We estimate a hydrothermal flux of 3.5 mol 3He yr−1 and a lower limit for the crustal flux at 1.6 10−7 mol 4He mol m−2 yr−1. In addition to providing constraints on helium isotope degassing fluxes in the Mediterranean, our simulations provide information on the ventilation of the deep Mediterranean waters which are useful for assessing NEMO-MED12 performance. This study is part of the work carried out to assess the robustness of the NEMO-MED12 model, which will be used to study the evolution of the climate and its effect on the biogeochemical cycles in the Mediterranean Sea, and to improve our ability to predict the future evolution of the Mediterranean Sea under the increasing anthropogenic pressure.

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Tremaskin, D. Yu, et I. A. Golubeva. « The Future of Helium Industry in Eastern Siberia, Problems and Solutions ». Chemistry and Technology of Fuels and Oils 630, n^o 2 (2022) : 51–56. http://dx.doi.org/10.32935/0023-1169-2022-630-2-51-56.

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The world production and consumption of helium are analyzed. Potential problems of the helium industry in Eastern Siberia have been identified. Variants of long-term storage of helium are proposed. The problem of helium transportation in Russia and the ways of its solution are considered.

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Ding, C. Y., et Y. H. Chen. « Turbulent properties of Helium convective shells of massive stars ». Monthly Notices of the Royal Astronomical Society 503, n^o 4 (6 avril 2021) : 6136–42. http://dx.doi.org/10.1093/mnras/stab910.

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ABSTRACT In this paper, turbulent properties and correlations of Helium convective shells (due to partial ionization of Helium) of 30 $\, \mathrm{M}_{\odot }$ star are researched. As evolution proceeds, the turbulence in Helium convective shells becomes more and more intense. Choosing the stellar models of which effective temperature is 10 000 Kelvin, it is found that the turbulent kinetic energy will increase in the Helium II (primary Helium ionization) zone but decrease in the Helium III (Helium secondary ionization) zone and the ratio of convective heat flux to the total heat flux will increase in the He ii convective zone and decrease in the He iii convective zone as the turbulent diffusion parameters’ values increase. This represents that the turbulent kinetic energy possibly transport outward as the turbulent diffusive parameters’ values increase.

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Danabalan, Diveena, Jon G. Gluyas, Colin G. Macpherson, Thomas H. Abraham-James, Josh J. Bluett, Peter H. Barry et Chris J. Ballentine. « The principles of helium exploration ». Petroleum Geoscience 28, n^o 2 (11 janvier 2022) : petgeo2021–029. http://dx.doi.org/10.1144/petgeo2021-029.

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Commercial helium systems have been found to date as a serendipitous by-product of petroleum exploration. There are nevertheless significant differences in the source and migration properties of helium compared with petroleum. An understanding of these differences enables prospects for helium gas accumulations to be identified in regions where petroleum exploration would not be tenable. Here we show how the basic petroleum exploration playbook (source, primary migration from the source rock, secondary longer distance migration, trapping) can be modified to identify helium plays. Plays are the areas occupied by a prospective reservoir and overlying seal associated with a mature helium source. This is the first step in identifying the detail of helium prospects (discrete pools of trapped helium). We show how these principles, adapted for helium, can be applied using the Rukwa Basin in the Tanzanian section of the East African Rift as a case study. A thermal hiatus caused by rifting of the continental basement has resulted in a surface expression of deep crustal gas release in the form of high-nitrogen gas seeps containing up to 10% 4He. We calculate the total likely regional source-rock helium generative capacity, identify the role of the Rungwe volcanic province in releasing the accumulated crustal helium and show the spatial control of helium concentration dilution by the associated volcanic CO2. Nitrogen, both dissolved and as a free-gas phase, plays a key role in the primary and secondary migration of crustal helium and its accumulation into what might become a commercially viable gas pool. This too is examined. We identify and discuss evidence that structures and seals suitable for trapping hydrocarbon and CO2 gases will likely also be efficient for helium accumulation on the timescale of the Rukwa Basin activity. The Rukwa Basin prospective recoverable P50 resources of helium have been independently estimated to be about 138 BSCF (billion standard cubic ft: 2.78 × 109 m3 at STP). If this volume is confirmed it would represent about 25% of the current global helium reserve. Two exploration wells, Tai 1 and Tai 2, completed by August 2021 have proved the presence of seal and reservoir horizons with the reservoirs containing significant helium shows.This article is part of the Energy Geoscience Series available at https://www.lyellcollection.org/cc/energy-geoscience-series

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Lu, Yanxia, Qing Peng et Chenguang Liu. « Ab Initio Investigation of Helium Mobility in La2Zr2O7 Pyrochlore ». Crystals 11, n^o 6 (10 juin 2021) : 667. http://dx.doi.org/10.3390/cryst11060667.

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The α-decay of incorporated actinides continuously produces helium, resulting in helium accumulation and causing security concerns for nuclear waste forms. The helium mobility is a key issue affecting the accumulation and kinetics of helium. The energy barriers and migration pathways of helium in a potential high-level nuclear waste forms, La2Zr2O7 pyrochlore, have been investigated in this work using the climbing image nudged elastic band method with density functional theory. The minimum energy pathway for helium to migrate in La2Zr2O7 is identified as via La–La interstitial sites with a barrier of 0.46 eV. This work may offer a theoretical foundation for further prospective studies of nuclear waste forms.

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Lutfin, Nursakinah Annisa, et Fauziah A. « METODA HARTREE FOCK UNTUK MENENTUKAN ENERGI TOTAL INTI HELIUM-4 ». PHYDAGOGIC Jurnal Fisika dan Pembelajarannya 3, n^o 1 (31 octobre 2020) : 1–7. http://dx.doi.org/10.31605/phy.v3i1.954.

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Helium-4 merupakan salah satu isotop Helium yang stabil. Perhitungan energi total Helium-4 pada level inti ditinjau dengan menganggap inti spherically symmetric. Pada penelitian ini dilakukan perhitungan energi keadaan dasar inti Helium-4 berdasarkan metoda Hartree Fock. Persamaan hamiltonian yang terdiri atas energi kinetik dan potensial dihitung menggunakan program Fortran. Berdasarkan hasil perhitungan yang dilakukan diperoleh energi total inti Helium-4 sebesar -28,4023952 MeV, memiliki kesalahan 0,70% jika dibandingkan dengan hasil penelitian lain dengan menggunakan metode yang sama. Namun memiliki kesalahan lebih kecil sebesar 0,36% jika dibandingkan dengan hasil eksperimen. Hal ini menunjukkan bahwa metode Hartree Fock sudah cukup baik digunakan untuk menghitung energi inti Helium-4.

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Zhao, Qiang, Zheng Zhang, Yang Li et Xiaoping Ouyang. « First-Principles Study on Various Point Defects Formed by Hydrogen and Helium Atoms in Tungsten ». Science and Technology of Nuclear Installations 2017 (2017) : 1–9. http://dx.doi.org/10.1155/2017/6547939.

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The different point defects formed by two hydrogen atoms or two helium atoms in tungsten were investigated through first-principles calculation. The energetically favorable site for a hydrogen atom is tetrahedral interstitial site while substitutional site is the most preferred site for a helium atom. The formation energies of two hydrogen or helium atoms are determined by their positions, and they are not simply 2 times the formation energy of a single hydrogen or helium atom’s defect. After relaxation, two adjacent hydrogen atoms are away from each other while helium atoms are close to each other. The reasons for the interaction between two hydrogen or helium atoms are also discussed.

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Renzler, Michael, Matthias Daxner, Nikolaus Weinberger, Stephan Denifl, Paul Scheier et Olof Echt. « On subthreshold ionization of helium droplets, ejection of He+, and the role of anions ». Phys. Chem. Chem. Phys. 16, n^o 41 (2014) : 22466–70. http://dx.doi.org/10.1039/c4cp03236e.

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Sojak, Stanislav, Jarmila Degmova, Pavol Noga, Vladimir Krsjak, Vladimir Slugen et Tielong Shen. « Bubble Swelling in Ferritic/Martensitic Steels Exposed to Radiation Environment with High Production Rate of Helium ». Materials 14, n^o 11 (1 juin 2021) : 2997. http://dx.doi.org/10.3390/ma14112997.

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Reduced-activativon ferritic/martensitic (RAFM) steels are prospective structural materials for fission/fusion nuclear applications because their radiation and swelling resistance outperforms their austenitic counterparts. In radiation environments with a high production rate of helium, such as fusion or spallation applications, these materials suffer from non-negligible swelling due to the inhibited recombination between vacancy and interstitial-type defects. In this work, swelling in helium-implanted Eurofer 97 steel is investigated with a focus on helium production rates in a wide range of helium/dpa ratios. The results show virtually no swelling incubation period preceding a steady-state swelling of about 2 × 10−4%/He-appm/dpa. A saturation of swelling above 5000 He-appm/dpa was observed and attributed to helium bubbles becoming the dominant sinks for new vacancies and helium atoms. Despite a relatively low irradiation temperature (65 ± 5 °C) and a rather high concentration of helium, transmission electron microscope (TEM) results confirmed a microstructure typical of ferritic/martensitic steels exposed to radiation environments with high production rates of helium.

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Chuang, P. S., H. H. Tsai, H. W. Chiang, F. Z. Hsiao, W. R. Liao, H. C. Li, W. S. Chiou, S. H. Chang et P. J. Wang. « Design and analysis of the helium purification system for the NSRRC cryogenic system ». IOP Conference Series : Materials Science and Engineering 1240, n^o 1 (1 mai 2022) : 012090. http://dx.doi.org/10.1088/1757-899x/1240/1/012090.

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Abstract Helium is an expensive consumable in cryogenic facilities and is used widely in space, medical and energy research. At NSRRC, liquid helium is used as a coolant for superconducting magnets and SRF cavities . Minor contaminants such as nitrogen, oxygen, moisture and oil will be picked up when liquid helium circulates in large scale cryogenic systems and such contaminants can crystalize and cause damage to the cold box turbo expanders resulting in system damage and failure . Therefore, a helium purification system is designed as an integral part of the cryogenic system to conserve helium by providing 99.9995% pure helium to the liquefier after eliminating contaminants. The NSRRC helium purification process is based on two principles, the first one being a cryo-sorption device using activated charcoal and a molecular sieve and the other being a cryo-condensation unit using a tubular heat exchanger. The purifier has been designed to purify impure helium with overestimated contaminants of as much as 2.5% nitrogen and 2.5% oxygen with a mass flow rate of 475 nm3/hr and delivering a pressure of 17 bar(a) of impure helium to the purifier, the actual impurity will be much lower than the actual design contaminants. In this paper, calculation and design of the helium purification system and components composed of one double pipe counter flow heat exchanger, one vessel and tube heat exchanger, one pre-cooler and one charcoal vessel will be discussed together with charcoal mass requirement calculations and design of other components. In NSRRC, helium is liquefied and is used as a coolant for the SRF system and for cryogenic undulators. During a cryogenic cycle in the cryogenic system, helium may pick up contaminants such as moisture, oxygen, oil, and nitrogen, which have a higher freezing point than liquid helium and will crystalize. These frozen impurities will then affect plant capacity and operation such as alternating flow characteristics, damaging moving parts like turbines in the cold box causing the overall cooling efficiency to drop. Eliminating the contaminants is therefore very important for the cryogenic system.

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Dewi, Jasinta D. M., et Onno R. Pols. « The evolution of close helium star to neutron star binaries ». Symposium - International Astronomical Union 212 (2003) : 410–11. http://dx.doi.org/10.1017/s0074180900212527.

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We present the evolution of helium stars in binary systems with a 1.4 M⊙ neutron-star companion which will produce double neutron-star binaries, i.e., systems with helium stars more massive than 2.5 M⊙. We found that mass transfer from helium star less massive than ~ 3.3 M⊙ will end up in a common-envelope phase. If the neutron star has enough time to complete the spiral-in before the core of the helium star collapses, the system will become a very tight double neutron-star binary (P ≈ 0d.01). More massive helium stars do not go through a dynamically-unstable mass transfer. The outcome of binaries with helium star in this range of mass is double-neutron star systems with period of 0d.1-1d, suggesting them to be the progenitor of the observed Galactic double neutron-star pulsars B 1913+16 and B 15344+12. Wide DNS pulsars like J 1518+4904 are produced from helium star-neutron star binaries which avoid Roche-lobe overflow. We are also able to distinguish the progenitors of Type Ib supernovae (as the high-mass helium stars or systems in wide orbits) from those of Type Ic supernovae (as the lower-mass helium stars or systems in close orbits).

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Doolette, David J., Richard N. Upton et Cliff Grant. « Altering blood flow does not reveal differences between nitrogen and helium kinetics in brain or in skeletal miracle in sheep ». Journal of Applied Physiology 118, n^o 5 (1 mars 2015) : 586–94. http://dx.doi.org/10.1152/japplphysiol.00944.2014.

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In underwater diving, decompression schedules are based on compartmental models of nitrogen and helium tissue kinetics. However, these models are not based on direct measurements of nitrogen and helium kinetics. In isoflurane-anesthetized sheep, nitrogen and helium kinetics in the hind limb ( n = 5) and brain ( n = 5) were determined during helium-oxygen breathing and after return to nitrogen-oxygen breathing. Nitrogen and helium concentrations in arterial, femoral vein, and sagittal sinus blood samples were determined using headspace gas chromatography, and venous blood flows were monitored continuously using ultrasonic Doppler. The experiment was repeated at different states of hind limb blood flow and cerebral blood flow. Using arterial blood gas concentrations and blood flows as input, parameters and model selection criteria of various compartmental models of hind limb and brain were estimated by fitting to the observed venous gas concentrations. In both the hind limb and brain, nitrogen and helium kinetics were best fit by models with multiexponential kinetics. In the brain, there were no differences in nitrogen and helium kinetics. Hind limb models fit separately to the two gases indicated that nitrogen kinetics were slightly faster than helium, but models with the same kinetics for both gases fit the data well. In the hind limb and brain, the blood:tissue exchange of nitrogen is similar to that of helium. On the basis of these results, it is inappropriate to assign substantially different time constants for nitrogen and helium in all compartments in decompression algorithms.

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Liu, Awen, Hefei Huang, Jizhao Liu, Zhenbo Zhu et Yan Li. « Helium bubble formation and evolution in NiMo-Y₂O₃ alloy under He ion irradiation ». Chinese Physics B 31, n^o 4 (1 mars 2022) : 046102. http://dx.doi.org/10.1088/1674-1056/ac3654.

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We report helium ion irradiation experiments for a new type of dispersion-strengthened NiMo-Y2O3 alloy with three different irradiation doses and varying irradiation dose rates at 750 °C to evaluate its helium-induced damage behavior. Transmission electron microscopy was used to reveal the evolution of helium bubbles after irradiation. The experimental results show that with increasing ion dose, the number density of helium bubbles increases continuously. However, the mean size of helium bubbles first increases and then decreases, mainly due to the varied ion dose rates. The volume fractions of helium bubbles in the three investigated samples after irradiation are 0.15%, 0.32%, and 0.27%, which are lower than that of the Hastelloy N alloy (0.58%) after similar irradiation conditions. This indicates that the NiMo-Y2O3 alloy exhibits better helium-induced-swelling resistance than the Hastelloy N alloy, highlighting its potential applicability to MSRs, from the perspective of irradiation performance.

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Wang, B., D. Liu, S. Jia et Z. Han. « Helium double-detonation explosions for the progenitors of type Ia supernovae ». Proceedings of the International Astronomical Union 9, S298 (mai 2013) : 442. http://dx.doi.org/10.1017/s1743921313007072.

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AbstractThermonuclear explosions from helium double-detonation sub-Chandrasekhar mass model have been considered as an alternative way for the production of type Ia supernovae (SNe Ia). In this work, we systematically studied the helium double-detonation model, in which a carbon–oxygen white dwarf (CO WD) accumulates a helium layer from a non-degenerate helium star.

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Baskes, M. I. « Recent Advances in Understanding Helium Embrittlement in Metals ». MRS Bulletin 11, n^o 4 (août 1986) : 14–18. http://dx.doi.org/10.1557/s0883769400069116.

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Helium is formed in metals as a secondary product of fission/fusion energy technology. Even though helium is chemically inert and essentially insoluble in metals, under specific exposure conditions it is known to cause them to lose their ductility. At high temperatures, helium atoms produced from the transmutation of 10B or from a two-step process with 58Ni in amounts as low as a few parts per million migrate to grain boundaries to cause inter-granular failure. Ion implantation of helium may cause a similar effect. More recently it has been found that helium produced from tritium decay at or slightly above room temperature also markedly degrades the mechanical properties of metals. In order to design alloys of the future it is necessary to understand the mechanisms responsible for this helium embrittlement.Early experiments found that helium is strongly trapped at radiation-produced defects in metals. Atomistic calculations using pair potential interactions verified these findings. It was initially thought that the helium embrittlement in metals was due to the trapping and subsequent bubble formation at radiation-induced defects. It has been shown, however, that helium may be trapped in metals even in the absence of radiation damage. Thomas et al. found that 3He generated at low temperatures from tritium decay remained trapped in nickel upon heating to 500°C. In both this experimentand a subsequentone in gold the helium was introduced without the production of radiation damage. In this second experiment Thomas used transmission electron microscopy to see in the gold small (10Å) bubbles that had been implanted with low-energy (sub-damage threshold) helium.

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Iben, Icko, et Alexander V. Tutukov. « Binary Stars and Planetary Nebulae ». Symposium - International Astronomical Union 131 (1989) : 505–22. http://dx.doi.org/10.1017/s0074180900139075.

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A non-negligible (∼ 15–20%) fraction of planetary nebulae is expected to be formed in close binaries in which one component fills its Roche lobe after the exhaustion of hydrogen or helium at its center. The nebula is ejected as a consequence of a frictional interaction between the stellar cores and a common envelope; the ionizing component of the central binary star may be a relatively high luminosity contracting star with a degenerate CO core, burning hydrogen or helium in a shell, or it may be a lower luminosity shell hydrogen-burning star with a degenerate helium core or a core helium-burning star. Even more exotic ionizing central stars are possible. Once the initial primary has become a white dwarf or neutron star, the secondary, after exhausting central hydrogen, will also fill its Roche lobe and eject a nebular shell in a common envelope event. The secondary becomes the ionizing star in a tight orbit with its compact companion. In all, there are roughly twenty different possibilities for the make-up of binary central stars, with the ionizing component being a post asymptotic giant branch star with a hydrogen- or helium-burning shell, a CO dwarf, a core helium-burning star, a shell helium-burning star with a degenerate CO core, a shell hydrogen-burning star with a degenerate helium core, or a helium degenerate dwarf, while its companion is a main sequence star, a CO degenerate dwarf, a helium star, a helium degenerate dwarf, or a neutron star. We estimate the occurrence frequency of several of these types and comment on the prior evolutionary history of 4 observed binary central stars.

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Nakoryakov, Vladimir, Oleg Vitovsky et Andrey Seryapin. « Helium production technology based on natural gas combustion and beneficial use of thermal energy ». Thermal Science 20, suppl. 1 (2016) : 19–22. http://dx.doi.org/10.2298/tsci151214227n.

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Helium is widely used in all industries, including power plant engineering. In recent years, helium is used in plants operating by the Brayton cycle, for example, in the nuclear industry. Using helium-xenon mixture in nuclear reactors has a number of advantages, and this area is rapidly developing. The hydrodynamics and mass transfer processes in single tubes with various cross-sections as well as in inter-channel space of heating tube bundle were studied at the Institute of Thermophysics, Siberian Branch of the Russian Academy of Sciences. Currently, there is a strongest shortage in helium production. The main helium production method consists in the liquefaction of the natural gas and subsequent separation of helium from remaining gas with its further purification using membranes.

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Huang, Chaoqiang, Guanyun Yan, Qiang Tian, Guangai Sun, Bo Chen, Liusi Sheng, Yaoguang Liu et al. « Evolution of Helium with Temperature in Neutron-Irradiated10B-Doped Aluminum by Small-Angle X-Ray Scattering ». Advances in Condensed Matter Physics 2014 (2014) : 1–6. http://dx.doi.org/10.1155/2014/506936.

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Helium status is the primary effect of material properties under radiation.10B-doped aluminum samples were prepared via arc melting technique and rapidly cooled with liquid nitrogen to increase the boron concentration during the formation of compounds. An accumulated helium concentration of ~6.2 × 1025 m−3was obtained via reactor neutron irradiation with the reaction of10B(n,α)7Li. Temperature-stimulated helium evolution was observed via small-angle X-ray scattering (SAXS) and was confirmed via transmission electron microscopy (TEM). The SAXS results show that the volume fraction of helium bubbles significantly increased with temperature. The amount of helium bubbles reached its maximum at 600°C, and the most probable diameter of the helium bubbles increased with temperature until 14.6 nm at 700°C. A similar size distribution of helium bubbles was obtained via TEM after in situ SAXS measurement at 700°C, except that the most probable diameter was 3.9 nm smaller.

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