Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)最新文献_第6页

Two-dimensional Model Of Stationary Plasma Thruster 静止等离子体推力器的二维模型

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589049

J. Boeuf, L. Pitchford

{"title":"Two-dimensional Model Of Stationary Plasma Thruster","authors":"J. Boeuf, L. Pitchford","doi":"10.1109/PLASMA.1994.589049","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.589049","url":null,"abstract":"A stationary plasma thruster (SPT) is an electromagnetic thruster design which has been developed primarily in the Former Soviet Union and which has properties which make it especially suitable for applications such as satellite station-keeping. The device geometry is cylindrical with a central dielectric rod and dielectric walls. A voltage (a few 100 V) is maintained between the anode (at one end of the cylinder) and the cathode (usually a hollow cathode or a filament slightly past the other end of the cylinder), and the current flowing through the device is on the order of several amps. Gas (usually xenon) flows in from the anode and is ionized by the electrons which are emitted from the cathode. An external magnetic field is applied primarily in the radial direction with a magnetic strength such that the electron gyroradius is much less than the device dimension but that the ion gyroradius is larger than the device dimensions. The SPT is a particular type of closed-drift thruster where ions are electrostatically accelerated in the thrust direction, with the accelerating electric field established by an electron current interacting with a transverse magnetic field. In such a configuration, an ion flux is produced with amore » high efficiency. The authors have developed a two-dimensional model for the purpose of elucidating the physical phenomena controlling the device performance and eventually developing scaling laws to guide the optimization of SPT`s. The model consists of fluid equations for the electrons and ions coupled to Poisson`s equation for the self-consistent electric field. The description of ion transport can be improved if necessary by solving the Vlasov equation with a particle method. Electron diffusion across the magnetic field is an important aspect of closed-drift thruster operation.« less","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127350330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Development Of Transient Internal Probe (tip) Magnetic Field Diagnostic 瞬态内探头(尖端)磁场诊断技术的发展

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589026

J. Galambos, M. Bohnet, T. Jarboe, A. T. Mattick

{"title":"Development Of Transient Internal Probe (tip) Magnetic Field Diagnostic","authors":"J. Galambos, M. Bohnet, T. Jarboe, A. T. Mattick","doi":"10.1109/PLASMA.1994.589026","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.589026","url":null,"abstract":"Development of Transient Internal Probe (TIP) Magnetic Field Diagnostic. J.P. Galambos, MA. Bohnet, T.R. Jarboe, A.T. Mattick, t h d j $ %&+ The Transient Internal Probe (TIP) is designed to permit measurement of internal magnetic fields in hot, high density plasmas. The concept consists of accelerating a probe to high velocities (2.2 Km/s) in order to minimize probe exposure time to plasma. Faraday rotation within the probe is used to measure the local magnetic field. An Argon laser illuminates the probe consisting of a Faraday-rotator material with a retro-reflector that r e m s the incident light to the detection system. Performance results of the light gas gun and optical detection system will shown. To date, the gas gun has been extensively tested consistently achieving velocities between 2 and 3 Ms. The probe and detection scheme have been tested by dropping the probe through a static magnetic field. Magnetic field resolution of 20 gauss and spatial resolution of 5 mm has been achieved. System frequency response is 10Mhz. Work is currently being conducted to integrate the diagnostic system with laboratory plasma experiments. Specifically a gas interfaced system has been developed to prevent helium muzzle gas from entering the plasma chamber with the probe. Additionally the probe must be separated from the sabot which protects the probe during acceleration in the gas gun. Data will be presented showing the results of various separation techniques. Results of pressure measurements illustrating the effectiveness of the gas interface system will also be presented. The diagnostic is scheduled to make measurements on the Helicity Injected Toms (HIT) at the University of Washington. 4P29","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130684648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Non-maxwellian Bounded Piasma Model Charge Exchange Ion Collisions 非麦克斯韦有界皮亚斯玛模型电荷交换离子碰撞

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589050

V. Godyak, V.P. Meytlis, H. Strauss

引用次数: 0

Dynamics Of Electrons In Anode Layer Of Hall-type Ion Source 霍尔型离子源阳极层电子动力学

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589011

S. Dudin, A. Zykov, A. Ushakov

{"title":"Dynamics Of Electrons In Anode Layer Of Hall-type Ion Source","authors":"S. Dudin, A. Zykov, A. Ushakov","doi":"10.1109/PLASMA.1994.589011","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.589011","url":null,"abstract":"Experimental results of investigations of electron dynamics in anode layer of Hall type ion source ``Radical`` are presented. The ion source consists of plate parallel cathode and anode separated by 4.5mm space. There is ring-like gap in cathode. Inner and outer parts of cathode are the poles of magnetic circuit which produces lateral magnetic field H = 0.7 {divided_by} 2 kE. Anode voltage U{sub a} was 0.6 {divided_by} 2 kV, pressure in discharge space was about 10{sup {minus}3} Tor. Glow cathode which might be moved in axial direction was used to investigate electron dynamics. Study of emission current distribution between the electrodes by additional electron injection had shown that only electrons from anode-cathode spacing are able to reach the anode. Dependence of emission current vs. distance between anode and emitter Z correlates with plasma potential distribution. The phenomenon of electron escape to cathode is interesting because even applying of cut-off bias at the emitter does not lead to vanishing of electron current. In addition, electron currents (about 10% of anode current) on cathode exists without external injection of electrons. There is considerable asymmetry of current distribution between inner and outer parts of the cathode. Energoanalysis of the escaping electrons hadmore » shown that electron loss was due to population through high energy tail of distribution function, which appeared as a result of electron-electron collisions.« less","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132137655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Surface Erosion Studies In A Plasmapropellant Interaction Experiment 等离子体-推进剂相互作用实验中的表面侵蚀研究

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588996

M. Bourham, J. Gilligan, C. Edwards, M. Nahm

引用次数: 0

Neon Dense Plasma Focus Point X-ray Source For /spl les/ 0.25 /spl mu/m lithography 氖致密等离子体焦点x射线源，用于/spl les/ 0.25 /spl mu/m光刻

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588868

R. Prasad, M. Krishnan, K. Berg, D. Conlon, J. Mangano

引用次数: 1

A Multi Stage Plasma-on-wire Z-pinch Configuration On The Megajoule Git-4 Generato 兆焦耳Git-4发电机上的多级等离子体线上z捏缩配置

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588964

B. Etlicher, A. Chuvatin, P. Zehnter, N. Edison, M. Darrigol, D. Friart, C. Nazet, P. Choi, C. Zoita, R. Baksht, I. Datsko, A. Fedunin, A. Shishlov, A. Kim, V. Kokshenev, B. Kovalchuk, A. Russkich, A. Shishlov, M.O. Kosheroi, D. A. Fedin

引用次数: 0

2 and 3-D MHD Calculations Of the plasma Focus and Flow-through Z-pinch 2、等离子体聚焦和流动的三维MHD计算

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.589018

J. EddIeman, C. Hartman, U. Shumlak

引用次数: 0

Dynamicsofa Very Intense Pulsed electron Beam 动态极强脉冲电子束

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588988

T. Sanford, J. Halbleib, D. Welch, R. Mock

{"title":"Dynamicsofa Very Intense Pulsed electron Beam","authors":"T. Sanford, J. Halbleib, D. Welch, R. Mock","doi":"10.1109/PLASMA.1994.588988","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.588988","url":null,"abstract":"A unique beam of pulsed electrons has been developed using the 19-MeV, 700-kA Hermes-III accelerator. The extended planar-anode diode is used to extract at large radius an annular electron beam from the accelerator and inject the resulting beam at small angle into a low-pressure gas cell, where the beam is rapidly charge neutralized and almost current neutralized. Under these conditions, the beam propagates nearly ballistically to a focus downstream of injection, where objects can be placed for irradiation and study. For a focal length of 78 cm, measurements with a segmented calorimeter show that this configuration can deliver an energy deposition of 200 J/g [20 Mrad] over a useful area of 70 cm{sup 2} and a 4-cm depth in graphite in 25 ns. Increasing the injection angle by reducing the AK gap permits higher doses over smaller areas to be achieved. Such beams are of interest for the study of material property changes from short-pulse high-energy depositions and for the study of electronic components response to thermal mechanical shock. The MAGIC/CYLTRAN model prediction of the radial energy deposition profile in the calorimeter is in excellent agreement with that measured at the focus. This experimentally verified model predicts that a peakmore » dose of 3,800 J/g (too high to be easily measured) with a HWHM radius of 1.3 cm can be generated at the focus in graphite if the focal length is decreased to 11 cm.« less","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126570172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Implosion Of Aluminum Wire Arrays Coated With Magnesium On The 4 Ma Double-eagle Generator 4毫安双鹰发电机上镀镁铝线阵列的内爆

Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS) Pub Date : 1994-06-06 DOI: 10.1109/PLASMA.1994.588968

C. Deeney, P.D. LePeIl, B. FaiIor, S. Wong, E. Yadlowski, B. Hazelton, J. Apruzese, K. Whitney, J. Thornhill, T. Nash

{"title":"Implosion Of Aluminum Wire Arrays Coated With Magnesium On The 4 Ma Double-eagle Generator","authors":"C. Deeney, P.D. LePeIl, B. FaiIor, S. Wong, E. Yadlowski, B. Hazelton, J. Apruzese, K. Whitney, J. Thornhill, T. Nash","doi":"10.1109/PLASMA.1994.588968","DOIUrl":"https://doi.org/10.1109/PLASMA.1994.588968","url":null,"abstract":"The authors have imploded aluminum wire arrays which were coated with magnesium on the 4 MA Double-EAGLE generator. The mass fraction of the magnesium varied from 0 to 70%. All the arrays were 15 mm in diameter, 2 cm long and, due to current and mass variations, the implosion times ranged from 85 t 95 ns. The aims were two-fold: (1) to investigate yield enhancement due to the mixing of near Z elements; and (2) to study what parts of the initial wire form the bulk of the on-axis pinch. The results they will present show an average increase in yield of 70% over pure aluminum arrays and 30 to 40% over pinches that were predominantly magnesium. This may be due to an effect discussed by J.P. Apruzese et al for Na-Ne near Z mixtures in which the decrease in the opacities of individual lines increased the escape probabilities. Furthermore, the data shows that by a 70:30 A1:Mg mix, the bulk of the radiation comes from the magnesium indicating that the outside of the wires preferentially dominate the heated core of the pinch. This is confirmed by the fact that the magnesium temperature is hotter than the aluminum. They willmore » present this data along with one-dimensional radiation-hydrodynamic and CRE modeling of these pinches.« less","PeriodicalId":254741,"journal":{"name":"Proceedings of 1994 IEEE 21st International Conference on Plasma Sciences (ICOPS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126081588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0