Plasma Diffusion in a Space-Simulat ion Beam-Plasma Discharge. E. 0. Hulburt Center for Space Research. and H. LEINBACH

Size: px
Start display at page:

Download "Plasma Diffusion in a Space-Simulat ion Beam-Plasma Discharge. E. 0. Hulburt Center for Space Research. and H. LEINBACH"

Transcription

1 ~~ :t I I tth. A0 A NAVAL RESEARCH LAS WASHINSTOI U C fls 20/9 PLASMA DIFFUSION IN A SPACESIMULATION BEAMPLASMA DISCHARSE. U) ~ Ff5 79 E P SZUSZCZEWICZ. U N WALKER UNCLASSIFIED IeL*3U5 SlIEADE iii. / I ~~~~~~.

2 w ~~~ q s ~W7, NRL Memorandum Report 3925 Plasma Diffusion in a SpaceSimulat ion BeamPlasma Discharge. 1 ~~~~ E. P. SZUSZCZEWICZ, D. N. WALKER, and J. C. HOLMES E. 0. Hulburt Center for Space Research and H. LEINBACH NOAAIERLISpa ce Environment Laboratory Boulder, Colorado Cm) February 12, 1979 s DDC~ III ~~~~~~~~~ 919 APR 5 III jjj ~~ 1 L UU L ~~~~ ~ ~ ~ 7: (8 ~ NAVAL RZSEA*CH LAIO~ATORY W.ikL.~ io. DC.. ~~ ~~~~~ A~ j...j j h i ubik IdIS~~ dhtilbsdon uaftai$u~... ~~~~~

3 1 SECURITY CLASSIFICATION OF T ~ 4IS PAGE (P7,.., 0.t. Lnf.,.d) DEDnOT IIM ~~ IITATI ~~~ l DAI READ INSTRUCT ION S E ~~~ ~~~~~~~~~~ ~~~ ~~ ~ BEFORE COMPLETIN G FORM I. REPORI NUMCER 2. GOVT ACCESSION NO 3. RECIPIENT S CATA LOG NUMUER NRL Memorandum Report TITLE (,d SvbISIl.) S. TYPE QF REPORT C PENIOO COVERED ILASMA DIFFUSION IN A SPACESIMULATION BEAM PLASMADISCHARGE Interim report on a continuing NRL problem. 4. PERFORMING ORG. REPORT NUMSER I. AUTNOR(.) I. CONTRACT OR GRANT NUMSER(.) E. P. Szuszczewtcz, D. N. Walker, J. C. Holmes and H. Lalnbach*. PERFORMING ORGANIZATION NAME AND ADDRESS Ia. PROGRAM ELEMENT. PROJECT. TAlE ~~ AR EA I wo rnc UNIT NUMSERS Naval Research Laboratory Washington, DC NRL Problem A02.11 Subtask RRD II. CONTROLLIN G OFFICE NAME AND ADDRESS 12. REPORT DATE Office of Naval Research February 12, 1979 Axilngton, VirginIa I). NUMSER OF PAGES 18 ta MONITORING AGENCY NAME I ADDRES S(Il.. dsll.c.u,,i I C.nIvWlMg OWe.) IS. SECURITY CLASS. (.5 ffis. e ~~..t J IC. Dt$TRISUTION STATEMENT (.1 ml. R.p.l) Approved for public release; distribution unllmlt.d. UNCLASSIFIED II.. OEC ~~ Al$lFICATION/OOwNGRAOING SC IAEDULE 17. OISTRISUTION STAT EMENT (.5 ft..b.,rw..,l., d I., 1S.c* 20. II dsu...l 1cS R.pocf) II. SUPPL EMENTARY NOTES *NO ~~ Jg ~~ /Space Environment Laboratory, Boulder, Colorado I. IS. ICY ROA DS (C.uiM,. io p sr ~~ old. St p ud Sd.RIIfr 5, block nid.bsf) Pl ma phyuira Energetic beasm Beam.pl nua Interactions 20. S$TRACT (c. IM.. tori?..ld. at... o. p ~~ d l* ẹs St block m bcc) ~~ ~ eetrvs density and temperature proflhss have been measured In a largefacility beam.pl ~~~ a dlsch ps (V 3 ~ 1.3 IC.V, ma) at low pressure (P 24(104 )Torr) and low magnetic (B 1.2 G) ~ The issulte follow an ezpon.ntlal behavior and axe found to be In good agreement with a simple diffusion model. The favorable comparison between theory and exp.rl. meet ylside the 6.ut.stimate of crosstisid electron diffusion (D ~ (noun) 2.2(10 6 )cm2/sic) under conditions Intended to simulate Sp.celabborn. beamplasma Investigation.. Thu value for D ~ (Continues) ~~~ DO, ~~~~~~ 1473 (DI TION OF I NOV CC 5 OS$OI.ETC C/N slo t I SECURITY CLAUIFICATION OF YNIC PAGE ( ~~~~.i, boa. ~~ IMRdJ, )..... f ~~~~~~. _ ~ L i ~~~, ~~~~ ~~~~~~~~~~~~~~~~~~~

4 _ SECURITY CLASSIFICATION OF TNIS PAGE (P7 ~.n D.a. Z&..d) 4bstract (Continued) )9v orders of magnitude larger than would be expected for a crossfield collisional diffusion process, a result which Is Identified with the turbulent state of collective beamplasma Interactions..L. SECURITY CLAS$IPICATION OF THIS PAOE ~~~ oa boa..u.,.d) I.. C ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~,, A ~ ~~

5 ~~ w ~ 1 ~~. CONTENTS I. D ~ TRODI.ICTION NTAL RESULTS II. ~~ PERD ~. III. THEORETICAL CONSIDERATIONS IV. COMPARISON BE1WEEN THEORY AND ~ CPERIMENT V. SU ~ *(ARY AC ~~~~ LEDG ~~~ NTS REFERENCES ~~~! ~ ION for White sectice W DOC 6ut SectI0i1 ~ 0 I UNANNOUN 0 ~~~ ~~~ s.i/or #. ~~~. ~~..f d, ~ ~ j :.i., ~~ al 1 ~~,p.. 11

6 C ~~~~~~.. c i PLASMA DIFFUSION IN A SPACES IMULAT ION BEAMPLASMADISCHARGE I. INTRODUCTION Beamplasma interactions have received increased attention in recent years largely as a result of considerations bearing on vehicle neutralization during spaceborne accelerator experiments, enhanced beamplasma ionization processes, and in general, collective phenomena initiated by beam injection into neutral gas and charged particle environments. With plans for Shuttleborne experiments directed at controlled beamplasma interactions and the use of beams to probe ionospheric/magnetospheric electric and magnetic fields, it became important to conduct laboratory simulations which supported the Shuttle plans and helped establish definitive Shuttleborne experi ments. k As part of just such a plan involving a continuing investigation of largefacility beamplasma interactions (Bernstein, et al, 1975,1977,1978) the Naval Research Laboratory (NRL )participated in a recent series of experi ments at the NASA Johnson Space Center (JSC). The NRL Note: Manuscript submitted Dsc.mber 11, p :

7 ~ w contribution involved the direct measurement of electron density and temperature under varying conditions of beam plasma and neutral gas parameters. Reported here are tile first large facility profiles of electron density and temperature under conditions of enhanced beamplasma ionization...conditions which have come to be known as the BPD, tile beamplasmadischarge (Getty and Smullin, 1963; Bernstein et al.,1978). The observed density profile is found to be in good agreement with a twodimensional diffusion model and this result makes possible the first estimate for the crossfield electron diffusion coefficient in a large facility BPD. In the following Sections the experiment is described, the theoretical model is defined, and the diffusion coefficient is derived. II. EXPERIMENTAL RESULTS The Experiment. The technique of the pulsedplasmaprobe (P 3 ) was employed to measure the beamplasma profile. The P 3 provides simultaneous measurements of N e ~ T e~ V 0, and ón (+P e n (k)) and is particularly useful under dynamic plasma conditions and in environments that can contaminate electrode surfaces (Holmes and Szuszczewicz, 1975 ; Szuszczewicz and Holmes, 1975,1976,1977). Both these conditions prevailed to various degrees in the JSC experi ments. The experimental configuration (similar to that de:cribed by Bernstein et ~~~ I r T TTTTTT. ~~~~~~~~~~~~~., ~~~~~~~

8 b W ~ Figure 1. The P 3 was mounted on a traversal mechanism positioned at approximately 8 m above the injection point of the beam. The tungsten cathode gun was operated at 63 ma and 1.3 Ky DC with the chamber pressure in the 2_4(lO _6 ) torr range. A combination of coil current and the Earth s field established vertical and horizontal component B fields at 3 z~ 1 2 gauss and B x_fo 2? gauss, respectively. Under these conditions a BPD was established and the probe traversal mechanism was exercised to determine the plasma s radial profile out to 4.6 m. The resulting measurements of T and N e e are presented in Figure 2. Following the diffusionmodel densityprofile predictions (discussed below) the experimental curves were fit with exponential distributions found to be T e [lo s KJ= 6.93 exp (r/l.99 ) (1) N e tio 6 cm 3 ] 7.01 exp (r/2.49) (2) III. THEORETICAL CONSIDERATIONS For purposes of comparison, a simple twodimensional diffusion model is developed which follows the approach used in the study of small laboratory arc plasmas by Bobm et al., (l949a). The approach suggests the consideration of a differential plasma element of thickness dr and of length h t. I.:i::. parallel and equal to the length of the beam as depicted in Figure 3. The differential element is taken outside the of the :e :nimat bb1 ~~~ : T : : ~~~ ~ ~~~~~~~~~~~~ I,

9 ~~~~ w along its length. The equilibrium density then arises from the balance of charge accretion by differential drift across the element, i.e., j e ~ 1 ) j e (1 ~~ 1 ) ~ and end losses (ZO and h) due to axial diffusion. Requiring ~~ e 1 dt = 0 and assuming an axial diffusion loss directly proportional to density (i.e., differential end losses 2 cx N e dr), the balance between production and loss requires (dj e /dr) h 5r 2a N ~ ~ r ( ) ~~ which is rewritten as dj e /dr IIII _2a : Ne /h. (4a) Similar arguments for the plasma s ion component yield dj 1 /dr = 2 c& ~ N i /b (4b) Independent of Eqs. (3) and (4) the diffusion currents and j can be described by their respective mobility ~ equations ( dn en dv ~ ~~~~~~~~~ ~~~~~~~~ ~~ ii ~ i ~~ ~ ( dn ~ en 1 dv and j D ~ ii ~~ + ~~~ i ~ j (5a) ~~~~~~~ (5b) where V is an electric potential and D e and D 1 are the perpendicular electron and ion diffusion coefficients, I respectively. Taking the onedimensional spacederivative 4 d/dr of Eqs. (5) and substituting (4) yields I

10 ~~ w. ~~ 2): ~~~ ~r (~~~ N e _ dv) dr 2 k dr\ e dr when N e N ~ and the terms have been rearranged. Addition of Eqs. (6) eliminates the putentialdependent term and results in d 2 N e = 2 h ~~ aeff T+ a. 1 DT. dr 2 I DDj (T ~ + T e ) N ~ 8 2 N e (7) with a solution (N exp (BR) N R ) 1 N e ~~ N. ~~ e ~ exp (8r) (exp (BR) exp(br) ~ + N exp (j3r) e e (exp (BR) exp (BR)) exp( ~ r) (8) t 4 I I In the limit R + ~~ the solution becomes N e N e exp ($r ) (9) where 2(a e D ~~~ ~l/2 ~ j T e + z D e T i ). (10) B DD ~ (T 1 + T e ) h : ~~~~~~~~~~ _ ~~~~~~~~~~~~~~. ~~~~~~~~~~ ~

11 ~~~~ w ~~~ IV. COMPARI SON BETWEEN THEORY AND EXPERIMENT The agreement between theoretical prediction (Eq.(9)) and experimental results is found to be good (see bottom panel, Fig. 2) and provides the opportunity for determining the effective electron diffusion perpendicular to the magnetic field, i.e., the radial diffusion in the model of Fig. 3. To accomplish this, consider 1im 8 ~~ _(D ~ h/ 2.49 (11) e)1 T 1 /T ~ s O where the value on the right side is taken from the exponential in Eq. (2). In addition, consider as the effective velocity of axially diffusing electrons which have sufficient energy to overcome chamber sheath potentials and be completely lost to the system. In this case, ~ :, /; ~i;: ; exp (_ev c /i T ~ e ) (12) where V ~ is the chambersheath potential. With V ~ (4.8 ~~~~ )kt 5 /e (Chen, 1965 ; Szuazczewicz, 1972) and 3 (1O ~ ) ~~ Eq. (12) yields ~~ (nom.) 7.0 (1O ~ ) cm /500 (13a) ~ (max) 2.8 (los ) cm /sec (13b ) 8, I ~~ ~~~~~

12 cz (mlxi ) 4.3 (l0 ~ ) cm /sec (13c) Substituting the values into Eq. (11) provides D ~ (nom ) 2.2 (10 6 ) cm 2 /sec (14a) D (max ) 8.8 (10 6 ) e cm 2 /sec (l4b) D ~ (min ) 1.3 (10 6 ) cm 2 /sec ( 14c) as the first experimental estimate of the effective electron diffusion coefficient perpendicular to the magnetic field in a BPD. The values for D are orders of magnitude larger than would be expected for crossfield collisional diffusion. This result in itself is not surprising since a variety of observations indicate that the diffusion of plasma across magnetic lines of force can be substantially enhanced above the collisional diffusion rate when fluctuating fields are present in the plasma (Spitzer, 1962 ; Kadomtsev, 1965). This is indeed the case in a BPD which has as one of its characteristics the presence of fluctuating electric fields that are associated with large amplitude plasma waves. The enhancement of diffusion in turbulent plasmas goes back to Bohm et al. (1949b) who semiempirically doscribed the rate by what has come to be known as the Bohm diffusion coefficient ~ D 6.25 (10 6 ) T B 5 B 1 czn 2 /sec (15) k lii I ~~~~~~~~~~~~~~~~ ~~~~~~~~~ j~~~v

13 ~~ w where LT j = e V and [B] gauss. For our nominal temperature of 3(1O ~ ) K and a total field B = 1.2 gauss ~ Eq. (13) yields D = B l.3(10 6 )cm 2 /sec. This calculation has not been intended to confirm or deny the validity of Eqs. (14) but has been presented as the only possible comparison with an existing concept of turbulent diffusion. While the Bohm formula appears to apply to a surprising number of different experiments, care must be exercised so that the illusion of universal validity does not automatically develop. It is evident that a firstprinciples derivation of the coefficient of turbulent diffusion cannot be obtained without a detailed investigation of the plasma, particularly the fluctuation power spectra and associated instability processes (Kadomtsev, 1965 ; Pap ~ adopou1os, private communication 1978). The experimental and theoretical aspects of these details, as they relate to the JSC experiments, are currently underway at NRL (Szuszczewicz and Papadopoulos, private communication 1978). V. SUMMARY The first experimental radial profiles of electron density and temperature in a large facility beamplasmadischarge are found to fit exponential functions defined by 1 and T e [ K] = 6.93 (10 ~ ) exp (r [ m] /1.99) 8 ~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~~

14 . N e (cm 3 ] = 7.01 (10 6 ) exp (r( m ] /2.49). ~ While the present stage of research does not provide a theoretical basis for the temperature distribution, the electron density results do agree wit.i a two c ir. ~ e:i ~ ioiia1 diffusion model which predicts N e N e exp (2./D h) ~ r } in the limiting case of large chambers with T j /T e ~~ s.o With taken as the effective velocity of axially diffusing electrons (assigned a nominal value of 7 (1O ~ ) cm/eec) the identity of the experimental profile with the theoretical prediction yields D L (nom) = 2.2(10 6 ) c111 2 /sec for the radial electron diffusion across a superimposed magnetic field. This is the first such determination in a largefacility BPD and points to a process substantially faster than crossfield collisionil diffusion. The reason for this is identified with the presence of large amplitude plasma waves and their associated electric fields. While enhanced crossfield diffusion appears to be a characteristic of many turbulent plasma environments, the observations reported here are particularly unique in that 4 the applied magnetic field is at best. ~~~ times weaker than in any other turbulent diffusion investigation. This points to the importance of an unequivocal determination, J 9,. i._ ~ ~~, ~~., ;: ~~~~.. ~~~~~~~~~~~~~ ~~~ wa.

15 ~~~~~~~ w. ( I of the turbulence spectra and the associated instability processes. This work is currently underway at NRL. ACKNOWLEDGEMENTS This work was supported by the Office of Naval Research under Program Element 6ll53N33 in Task Area RR The authors would like to thank Drs. Owen Oarriott and H. Friedman for suggesting and making possible the NRL participation in the JSC experiments. We also wish to thank W. Bernstein and Dr. D. Papadopoulos for their review of the manuscript, their support in the activities, and their helpful suggestions. Sincere thanks are also extended to the large number of people at JSC who helped rig the P 3 configuration and the traversal mechanism. 10 j ~~~ ;i~~~~ ~~~~~~~~~. ~

16 ~~ w ( REFE RENCES Bernstein, W., H. Leinbach, H. Cohen, P.S. Wilson, T.N. Davis, T. Hallinan, B. Baker, J. Martz, R. Zeinike, and W. Huber, Laboratory observations of RF emissions at W pe and (N + I)W CE in electron beamplasma and beamplasma interactions, J.Geophys.Res. 80, 4375, Bernstein, W., H. Leinbach, and B. Baker, Preliminary results from the electron beamplasma experiments in the very large vacuum facilities at Plum Brook and Johnson Space Center, NOAA Technical Memorandum ERLSEL 5 August Bernstein, W., H. Leinbach, P. Kellog, S. Manson, T. Hallinan, O.K. Garriott, A. Konradi, J. McCoy, P. Daly, B. Baker, and H.R. Anderson, Electron beam injection experiments : The beamplasma discharge at low pressures and magnetic field strengths, Geophys.Res. Lett. 5, 127, Bohm, D., E.H.S. Burbop, H.S.W. Massey, and R.M. Williams, in Characteristics of Electrical Discharges in Magnetic Fields, edited by A. Guthrie and R.K. Wakerling, McGraw Hill, New York l949a, Ch. 9. Bohm, D., E.H.S. Burhop, and R.S.W. Massey, in Characteristics of Electrical Discharges in Magnetic Fields, edited by 4 A. Guthrie and R.K. Wakerling, McGrawHill, New York 1949b, Ch ~~ ~~~~~~~~~~~~~~

17 4 Chen, F.F., in Plasma Diagnostic Techniques, edited by R.H. Huddlestone and S.L. Leonard, Academic, New York 1 ~ )U5, Cli. 4. Holmes, JC. and E.P. Szuszczewicz, A versatile plasma probe, Rev.Sci.Instr. 46, 592, Kadomtsev, B.B., Plasma Turbulence, Academic Press, New York, Spitzer L. Jr., Physics of Fully Ionized Gases, John Wiley, New York, Szuszczewicz, E.P., Area influences and floating potentials in Langmuir probe measurements, J.Appl.Phys. 43, 874, 1972 ; V 4.8kT 0 e /e has been selected as a nominal value since the wall conditions are considered more appropriately identified with the thin sheath conditions in ~ Figs. 3 and 6 of this Ref. Szuszczewicz, E.P., and J.C. Holmes, Surface contamination of active electrodes in plasmaè: Distortion of conventional Laxigmuir probe measurements, J.Appl.Phys. 46, 5134, Szuszczewicz, E.P., and J.C. Holmes, Reentry plasma diagnostics with a pulsed plasma probe, AIAA Paper No , AIAA 9th Fluid and Plasma Dynamics Conference (San Diego, CA/July 1976). Szuszczewicz, E.P. and J.C. Holmes, Observations of electron temperature gradients in midlatitude E 8 layers, J. Geophys. Res. 82, 5073, a ~~~~ ~~~~~~ ~ ~~~~~~~~~~

18 ~~~ w ( I 30m COLLECTOR SUPPRESSO PHOTOMETER R/ ~~~~~~~~~~~~~~ j ~~~~ S _ ~~~~~~~~~ _ ~~~ ITV GUN I 1 I I TRAVERSAL j 8m. AXIS I # 1 20m Fig. I Experiment configuration utilized in the largefacility beamplasma invest igationa at the Johnson Space Center.. ~~~~~~~ 13 : ~~~~~~~~ 7 ~~~~~ ~~~~~~ ~~~~~~~~~~~~~~~~~ ~~~~~~~ ; ~~~~~~~~~~~~~ d ~~

19 ~~~ w 1 I I I I I I I I I I I I I I I 4 3. ELECTRON TEMPERATURE i. T.[1 ~ KJ =6.93 exp( ni 99) 5 4 ELECTRON ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ RADIAL DISTA NCE FROM CENTER [MI I I I I I Fig. 2 Ra dial profiles of electron density and temperature under conditions of the beamplassm discharge. I $ 1 j I 14 i S ~~~

20 ~~~~ w ~ ~~ ANODE I ~~ Ii. ( ) j ~ (r i dr) I I! r R r+dr.1 I V I Fig. 3 Aas*~~ sd configuration for diffusionmodel calculation s. 15 ~~~~ ~~~~~~~~~~~~~~. ~. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~ ~~~~~~~ ~.

Plasma Formation in the Near Anode Region in Hall Thrusters

Plasma Formation in the Near Anode Region in Hall Thrusters 41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 10-13 July 2005, Tucson, Arizona AIAA 2005-4059 41 st AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit AIAA-2005-4059 Plasma Formation

More information

Nonlinear Diffusion in Magnetized Discharges. Francis F. Chen. Electrical Engineering Department

Nonlinear Diffusion in Magnetized Discharges. Francis F. Chen. Electrical Engineering Department Nonlinear Diffusion in Magnetized Discharges Francis F. Chen Electrical Engineering Department PPG-1579 January, 1998 Revised April, 1998 Nonlinear Diffusion in Magnetized Discharges Francis F. Chen Electrical

More information

A note on the plasma sheath and the Bohm Criterion

A note on the plasma sheath and the Bohm Criterion A note on the plasma sheath and the Bohm Criterion G.D. Severn Dept. of Physics, University of San Diego, San Diego CA 92110 (Dated: April 6, 2006) PACS numbers: 52.27.Aj, 52.27.Cm The word sheath in connection

More information

One dimensional hybrid Maxwell-Boltzmann model of shearth evolution

One dimensional hybrid Maxwell-Boltzmann model of shearth evolution Technical collection One dimensional hybrid Maxwell-Boltzmann model of shearth evolution 27 - Conferences publications P. Sarrailh L. Garrigues G. J. M. Hagelaar J. P. Boeuf G. Sandolache S. Rowe B. Jusselin

More information

Beams and magnetized plasmas

Beams and magnetized plasmas Beams and magnetized plasmas 1 Jean-Pierre BOEUF LAboratoire PLAsma et Conversion d Energie LAPLACE/ CNRS, Université Paul SABATIER, TOULOUSE Beams and magnetized plasmas 2 Outline Ion acceleration and

More information

A L A BA M A L A W R E V IE W

A L A BA M A L A W R E V IE W A L A BA M A L A W R E V IE W Volume 52 Fall 2000 Number 1 B E F O R E D I S A B I L I T Y C I V I L R I G HT S : C I V I L W A R P E N S I O N S A N D TH E P O L I T I C S O F D I S A B I L I T Y I N

More information

Diffusion equation, flux, diffusion coefficient scaling. Diffusion in fully ionized plasma vs. weakly ionized plasma. n => Coulomb collision frequency

Diffusion equation, flux, diffusion coefficient scaling. Diffusion in fully ionized plasma vs. weakly ionized plasma. n => Coulomb collision frequency Last Time Diffusion in plasma: the main reason why we need to control it (i.e. using magnetic field) Diffusion equation, flux, diffusion coefficient scaling o o t nx,t Dn D2 nx,t o D ~ L 2 T Diffusion

More information

Low Temperature Plasma Technology Laboratory

Low Temperature Plasma Technology Laboratory Low Temperature Plasma Technology Laboratory Equilibrium theory for plasma discharges of finite length Francis F. Chen and Davide Curreli LTP-6 June, Electrical Engineering Department Los Angeles, California

More information

Analytic Expression For the Electric Potential in the Plasma Sheath

Analytic Expression For the Electric Potential in the Plasma Sheath 884 IEEE TRANSACTIONS ON PLASMA SCIENCE. VOL. 17. NO. 6. DECEMBER 1989 Analytic Expression For the Electric Potential in the Plasma Sheath TERRENCE E. SHERIDAN, JR. AND JOHN A GOREE Abstract-An expression

More information

Software Process Models there are many process model s in th e li t e ra t u re, s om e a r e prescriptions and some are descriptions you need to mode

Software Process Models there are many process model s in th e li t e ra t u re, s om e a r e prescriptions and some are descriptions you need to mode Unit 2 : Software Process O b j ec t i ve This unit introduces software systems engineering through a discussion of software processes and their principal characteristics. In order to achieve the desireable

More information

The low-field density peak in helicon discharges

The low-field density peak in helicon discharges PHYSICS OF PLASMAS VOLUME 10, NUMBER 6 JUNE 2003 Francis F. Chen a) Electrical Engineering Department, University of California, Los Angeles, Los Angeles, California 90095-1597 Received 10 December 2002;

More information

Computational Modeling of a High Power Plasma Source for Material Interaction Experiments

Computational Modeling of a High Power Plasma Source for Material Interaction Experiments Computational Modeling of a High Power Plasma Source for Material Interaction Experiments IEPC-2013-224 Presented at the 33rd International Electric Propulsion Conference, The George Washington University

More information

Chaotic-to-ordered state transition of cathode-sheath instabilities in DC glow discharge plasmas

Chaotic-to-ordered state transition of cathode-sheath instabilities in DC glow discharge plasmas PRAMANA c Indian Academy of Sciences Vol. 67, No. 2 journal of August 2006 physics pp. 299 304 Chaotic-to-ordered state transition of cathode-sheath instabilities in DC glow discharge plasmas MD NURUJJAMAN

More information

IflIIICIII81I EIIEEIIEEEEE. mm--mm.. AD-AI NAVAL RESEARCH LAB WASHINGTON DC F/B 20/9

IflIIICIII81I EIIEEIIEEEEE. mm--mm.. AD-AI NAVAL RESEARCH LAB WASHINGTON DC F/B 20/9 AD-AI04 937 NAVAL RESEARCH LAB WASHINGTON DC F/B 20/9 EIIEEIIEEEEE THRESHOLD CRITERIA FOR A SPACE-SIMULATION BEAM-PLASMA-DISCHARE-ETC(U) SEP 81 E P SZUSZCZEWICZ. K PAPADOPOULOS UNCLASSIFIED NRL-MR-4608

More information

DATE ~~~ 6O 300 N1. nbc OF / END FJLIEEO

DATE ~~~ 6O 300 N1. nbc OF / END FJLIEEO / AD AO6O 390 SOUTHERN METHODIST UNIV DALLAS TX DEPT OF OPERATIONS ETC F/G 12/1 APPROXIMATIONS TO THE INVERSE CUMULATIVE NORMAL FUNCTION FOR US ETCH) ) JUL 78 8 W SCHMEISER N00014 77eC Ot,25 UNCLASSIFIED

More information

TARGET PLATE CONDITIONS DURING STOCHASTIC BOUNDARY OPERATION ON DIII D

TARGET PLATE CONDITIONS DURING STOCHASTIC BOUNDARY OPERATION ON DIII D GA A25445 TARGET PLATE CONDITIONS DURING STOCHASTIC BOUNDARY OPERATION ON DIII D by J.G. WATKINS, T.E. EVANS, C.J. LASNIER, R.A. MOYER, and D.L. RUDAKOV JUNE 2006 QTYUIOP DISCLAIMER This report was prepared

More information

arxiv:physics/ v1 [physics.plasm-ph] 5 Nov 2004

arxiv:physics/ v1 [physics.plasm-ph] 5 Nov 2004 Ion Resonance Instability in the ELTRAP electron plasma G. Bettega, 1 F. Cavaliere, 2 M. Cavenago, 3 A. Illiberi, 1 R. Pozzoli, 1 and M. Romé 1 1 INFM Milano Università, INFN Sezione di Milano, Dipartimento

More information

Langmuir Probe Measurements of a Magnetoplasmadynamic Thruster

Langmuir Probe Measurements of a Magnetoplasmadynamic Thruster Langmuir Probe Measurements of a Magnetoplasmadynamic Thruster IEPC-201-187 Presented at the rd International Electric Propulsion Conference, The George Washington University Washington, D.C. USA Yang

More information

Observation of Neo-Classical Ion Pinch in the Electric Tokamak*

Observation of Neo-Classical Ion Pinch in the Electric Tokamak* 1 EX/P6-29 Observation of Neo-Classical Ion Pinch in the Electric Tokamak* R. J. Taylor, T. A. Carter, J.-L. Gauvreau, P.-A. Gourdain, A. Grossman, D. J. LaFonteese, D. C. Pace, L. W. Schmitz, A. E. White,

More information

The Q Machine. 60 cm 198 cm Oven. Plasma. 6 cm 30 cm. 50 cm. Axial. Probe. PUMP End Plate Magnet Coil. Filament Cathode. Radial. Hot Plate.

The Q Machine. 60 cm 198 cm Oven. Plasma. 6 cm 30 cm. 50 cm. Axial. Probe. PUMP End Plate Magnet Coil. Filament Cathode. Radial. Hot Plate. 1 The Q Machine 60 cm 198 cm Oven 50 cm Axial Probe Plasma 6 cm 30 cm PUMP End Plate Magnet Coil Radial Probe Hot Plate Filament Cathode 2 THE Q MACHINE 1. GENERAL CHARACTERISTICS OF A Q MACHINE A Q machine

More information

Low Temperature Plasma Technology Laboratory

Low Temperature Plasma Technology Laboratory Low Temperature Plasma Technology Laboratory CENTRAL PEAKING OF MAGNETIZED GAS DISCHARGES Francis F. Chen and Davide Curreli LTP-1210 Oct. 2012 Electrical Engineering Department Los Angeles, California

More information

Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster

Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster Measurements of Plasma Potential Distribution in Segmented Electrode Hall Thruster Y. Raitses, D. Staack and N. J. Fisch Princeton University Plasma Physics Laboratory P. O. Box 451, Princeton, NJ 08543

More information

Fundamentals of Plasma Physics Transport in weakly ionized plasmas

Fundamentals of Plasma Physics Transport in weakly ionized plasmas Fundamentals of Plasma Physics Transport in weakly ionized plasmas APPLAuSE Instituto Superior Técnico Instituto de Plasmas e Fusão Nuclear Luís L Alves (based on Vasco Guerra s original slides) 1 As perguntas

More information

Contents: 1) IEC and Helicon 2) What is HIIPER? 3) Analysis of Helicon 4) Coupling of the Helicon and the IEC 5) Conclusions 6) Acknowledgments

Contents: 1) IEC and Helicon 2) What is HIIPER? 3) Analysis of Helicon 4) Coupling of the Helicon and the IEC 5) Conclusions 6) Acknowledgments Contents: 1) IEC and Helicon 2) What is HIIPER? 3) Analysis of Helicon 4) Coupling of the Helicon and the IEC 5) Conclusions 6) Acknowledgments IEC:! IEC at UIUC modified into a space thruster.! IEC has

More information

Executive Committee and Officers ( )

Executive Committee and Officers ( ) Gifted and Talented International V o l u m e 2 4, N u m b e r 2, D e c e m b e r, 2 0 0 9. G i f t e d a n d T a l e n t e d I n t e r n a t i o n a2 l 4 ( 2), D e c e m b e r, 2 0 0 9. 1 T h e W o r

More information

Confinement of toroidal non-neutral plasma

Confinement of toroidal non-neutral plasma 10th International Workshop on Non-neutral Plasmas 28 August 2012, Greifswald, Germany 1/20 Confinement of toroidal non-neutral plasma in magnetic dipole RT-1: Magnetospheric plasma experiment Visualized

More information

Sheared Flow Stabilization in the Z-Pinch

Sheared Flow Stabilization in the Z-Pinch 1 IF/P7-28 Sheared Flow Stabilization in the Z-Pinch U. Shumlak, C.S. Adams, J.M. Blakely, B.J. Chan, R.P. Golingo, S.D. Knecht, B.A. Nelson, R.J. Oberto, M.R. Sybouts, and G.V. Vogman Aerospace & Energetics

More information

Confinement of toroidal non-neutral plasma in Proto-RT

Confinement of toroidal non-neutral plasma in Proto-RT Workshop on Physics with Ultra Slow Antiproton Beams, RIKEN, March 15, 2005 Confinement of toroidal non-neutral plasma in Proto-RT H. Saitoh, Z. Yoshida, and S. Watanabe Graduate School of Frontier Sciences,

More information

A0A TEXAS UNIV AT AUSTIN DEPT OF CHEMISTRY F/G 7/5 PHOTOASSISTED WATER-GAS SHIFT REACTION ON PLATINIZED T7TANIAI T--ETCIUI

A0A TEXAS UNIV AT AUSTIN DEPT OF CHEMISTRY F/G 7/5 PHOTOASSISTED WATER-GAS SHIFT REACTION ON PLATINIZED T7TANIAI T--ETCIUI AA113 878 TEXAS UNIV AT AUSTIN DEPT OF CHEMISTRY F/G 7/5 PHOTOASSISTED WATER-GAS SHIFT REACTION ON PLATINIZED T7TANIAI T--ETCIUI APR 82 S FANG. 8 CHEN..J M WHITE N14-75-C-922 UNCLASSIFIED NL OFFICE OF

More information

REPORT DOCUMENTATION PAGE

REPORT DOCUMENTATION PAGE REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions,

More information

Study of DC Cylindrical Magnetron by Langmuir Probe

Study of DC Cylindrical Magnetron by Langmuir Probe WDS'2 Proceedings of Contributed Papers, Part II, 76 8, 22. ISBN 978-737825 MATFYZPRESS Study of DC Cylindrical Magnetron by Langmuir Probe A. Kolpaková, P. Kudrna, and M. Tichý Charles University Prague,

More information

Confinement of toroidal non-neutral plasma in Proto-RT

Confinement of toroidal non-neutral plasma in Proto-RT Workshop on Physics with Ultra Slow Antiproton Beams, RIKEN, March 15, 2005 Confinement of toroidal non-neutral plasma in Proto-RT H. Saitoh, Z. Yoshida, and S. Watanabe Graduate School of Frontier Sciences,

More information

Defense Technical Information Center Compilation Part Notice

Defense Technical Information Center Compilation Part Notice UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP012539 TITLE: Investigation of the Expansion Rate Scaling of Plasmas in the Electron Diffusion Gauge Experiment DISTRIBUTION:

More information

Production of Over-dense Plasmas by Launching. 2.45GHz Electron Cyclotron Waves in a Helical Device

Production of Over-dense Plasmas by Launching. 2.45GHz Electron Cyclotron Waves in a Helical Device Production of Over-dense Plasmas by Launching 2.45GHz Electron Cyclotron Waves in a Helical Device R. Ikeda a, M. Takeuchi a, T. Ito a, K. Toi b, C. Suzuki b, G. Matsunaga c, S. Okamura b, and CHS Group

More information

Dense plasma formation on the surface of a ferroelectric cathode

Dense plasma formation on the surface of a ferroelectric cathode Vacuum ] (]]]]) ]]] ]]] www.elsevier.com/locate/vacuum Dense plasma formation on the surface of a ferroelectric cathode K. Chirko, Ya.E. Krasik, A. Sayapin, J. Felsteiner Physics Department, Technion Israel

More information

P a g e 5 1 of R e p o r t P B 4 / 0 9

P a g e 5 1 of R e p o r t P B 4 / 0 9 P a g e 5 1 of R e p o r t P B 4 / 0 9 J A R T a l s o c o n c l u d e d t h a t a l t h o u g h t h e i n t e n t o f N e l s o n s r e h a b i l i t a t i o n p l a n i s t o e n h a n c e c o n n e

More information

OH BOY! Story. N a r r a t iv e a n d o bj e c t s th ea t e r Fo r a l l a g e s, fr o m th e a ge of 9

OH BOY! Story. N a r r a t iv e a n d o bj e c t s th ea t e r Fo r a l l a g e s, fr o m th e a ge of 9 OH BOY! O h Boy!, was or igin a lly cr eat ed in F r en ch an d was a m a jor s u cc ess on t h e Fr en ch st a ge f or young au di enc es. It h a s b een s een by ap pr ox i ma t ely 175,000 sp ect at

More information

STRONG DOUBLE LAYER STRUCTURE IN THERMIONIC VACUUM ARC PLASMA *

STRONG DOUBLE LAYER STRUCTURE IN THERMIONIC VACUUM ARC PLASMA * STRONG DOUBLE LAYER STRUCTURE IN THERMIONIC VACUUM ARC PLASMA * V. TIRON 1, L. MIHAESCU 1, C.P. LUNGU 2 and G. POPA 1 1 Faculty of Physics, Al. I. Cuza University, 700506, Iasi, Romania 2 National Institute

More information

PRINCIPLES OF PLASMA DISCHARGES AND MATERIALS PROCESSING

PRINCIPLES OF PLASMA DISCHARGES AND MATERIALS PROCESSING PRINCIPLES OF PLASMA DISCHARGES AND MATERIALS PROCESSING Second Edition MICHAEL A. LIEBERMAN ALLAN J, LICHTENBERG WILEY- INTERSCIENCE A JOHN WILEY & SONS, INC PUBLICATION CONTENTS PREFACE xrrii PREFACE

More information

11. Discharges in Magnetic Fields

11. Discharges in Magnetic Fields Contrib. Plasma Phys. 26 (1986) 1, 13-17 Sudden Jumps, Hysteresis, and Negative Resistance in an Argon Plasma Discharge 11. Discharges in Magnetic Fields R. A. BOSCR and R. L. MERLINO Department of Physics

More information

Control of gas discharge plasma properties utilizing nonlocal electron energy distribution functions DOE-OFS Plasma Science Center

Control of gas discharge plasma properties utilizing nonlocal electron energy distribution functions DOE-OFS Plasma Science Center 1 Control of gas discharge plasma properties utilizing nonlocal electron energy distribution functions DOE-OFS Vladimir Demidov Current cooperation with: Mark Koepke (WVU), Igor Kaganovich (PPPL), Yevgeny

More information

Langmuir Probes as a Diagnostic to Study Plasma Parameter Dependancies, and Ion Acoustic Wave Propogation

Langmuir Probes as a Diagnostic to Study Plasma Parameter Dependancies, and Ion Acoustic Wave Propogation Langmuir Probes as a Diagnostic to Study Plasma Parameter Dependancies, and Ion Acoustic Wave Propogation Kent Lee, Dean Henze, Patrick Smith, and Janet Chao University of San Diego (Dated: May 1, 2013)

More information

MAGNETIC NOZZLE PLASMA EXHAUST SIMULATION FOR THE VASIMR ADVANCED PROPULSION CONCEPT

MAGNETIC NOZZLE PLASMA EXHAUST SIMULATION FOR THE VASIMR ADVANCED PROPULSION CONCEPT MAGNETIC NOZZLE PLASMA EXHAUST SIMULATION FOR THE VASIMR ADVANCED PROPULSION CONCEPT ABSTRACT A. G. Tarditi and J. V. Shebalin Advanced Space Propulsion Laboratory NASA Johnson Space Center Houston, TX

More information

Robert A. Meger Richard F. Fernster Martin Lampe W. M. Manheimer NOTICE

Robert A. Meger Richard F. Fernster Martin Lampe W. M. Manheimer NOTICE Serial Number Filing Date Inventor 917.963 27 August 1997 Robert A. Meger Richard F. Fernster Martin Lampe W. M. Manheimer NOTICE The above identified patent application is available for licensing. Requests

More information

BENCHINGMARK AND IMPLEMENTATION OF A GENERALIZED MITL FLOW MODEL

BENCHINGMARK AND IMPLEMENTATION OF A GENERALIZED MITL FLOW MODEL BENCHINGMARK AND IMPLEMENTATION OF A GENERALIED MITL FLOW MODEL P.F. Ottinger a, J.W. Schumer, D.D. Hinshelwood, and R.J. Allen Plasma Physics Division, Naval Research Laboratory, Washington, DC 237 Abstract

More information

Particle-In-Cell Simulations of a Current-Free Double Layer

Particle-In-Cell Simulations of a Current-Free Double Layer Particle-In-Cell Simulations of a Current-Free Double Layer S. D. Baalrud 1, T. Lafleur, C. Charles and R. W. Boswell American Physical Society Division of Plasma Physics Meeting November 10, 2010 1Present

More information

173 ENERGETIC ION BERN-PLASMA INTERACTIONS(U) PRINCETON i/i UNIV N J PLASMA PHYSICS LAB P KULSRUD 09 MAR 84 RFOSR-TR AFOSR

173 ENERGETIC ION BERN-PLASMA INTERACTIONS(U) PRINCETON i/i UNIV N J PLASMA PHYSICS LAB P KULSRUD 09 MAR 84 RFOSR-TR AFOSR ,-AD-A14@ 173 ENERGETIC ION BERN-PLASMA INTERACTIONS(U) PRINCETON i/i UNIV N J PLASMA PHYSICS LAB P KULSRUD 09 MAR 84 RFOSR-TR--84-9228 AFOSR-83-0203 UNCLRSSIFIED F/G 20/9 NL iii LL~ -A M ma -wn STMaRCS1g3-

More information

Plasma shielding during ITER disruptions

Plasma shielding during ITER disruptions Plasma shielding during ITER disruptions Sergey Pestchanyi and Richard Pitts 1 Integrated tokamak code TOKES is a workshop with various tools objects Radiation bremsstrahlung recombination s line s cyclotron

More information

Ionization Detectors

Ionization Detectors Ionization Detectors Basic operation Charged particle passes through a gas (argon, air, ) and ionizes it Electrons and ions are collected by the detector anode and cathode Often there is secondary ionization

More information

Multi-fluid Simulation Models for Inductively Coupled Plasma Sources

Multi-fluid Simulation Models for Inductively Coupled Plasma Sources Multi-fluid Simulation Models for Inductively Coupled Plasma Sources Madhusudhan Kundrapu, Seth A. Veitzer, Peter H. Stoltz, Kristian R.C. Beckwith Tech-X Corporation, Boulder, CO, USA and Jonathan Smith

More information

I I ! MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A

I I ! MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS-1963-A , D-Ri33 816 ENERGETIC ION BERM PLASMA INTERRCTIONS(U) PRINCETON / UNIV N J PLASMA PHYSICS LAB R MI KULSRUD 30 JUN 83 UNCLSSIFEDAFOSR-TR-83-0816 AFOSR-81-0106F/209 N EEEEONEE"_ I I 11111.!2 1.1. IL MICROCOPY

More information

June 5, 2012: Did you miss it? No Problem. Next chance in Venus in Front of the Sun and there is more: plasma imaging!

June 5, 2012: Did you miss it? No Problem. Next chance in Venus in Front of the Sun and there is more: plasma imaging! July 18 20, 2012 5th Int. Workshop on "Thin Films Applied To Superconducting RF And New Ideas For Pushing The Limits Of RF Superconductivity" Jefferson Lab, VA Strong localization of ionization in high

More information

Sheaths: More complicated than you think a

Sheaths: More complicated than you think a PHYSICS OF PLASMAS 12, 055502 2005 Sheaths: More complicated than you think a Noah Hershkowitz b University of Wisconsin-Madison, Madison, Wisconsin 53706 Received 7 December 2004; accepted 7 February

More information

Plasma Fusion Center Massachusetts Institute of Technology Cambridge, MA Burrell, K.H. General Atomics PO Box San Diego, CA

Plasma Fusion Center Massachusetts Institute of Technology Cambridge, MA Burrell, K.H. General Atomics PO Box San Diego, CA PFC/JA-95-28 Edge Turbulence Measurements during the L- to H-Mode Transition by Phase Contrast Imaging on DIII-Dt Coda, S.; Porkolab, M.; Plasma Fusion Center Massachusetts Institute of Technology Cambridge,

More information

Magnetic fluctuations of a large nonuniform plasma column

Magnetic fluctuations of a large nonuniform plasma column PHYSICS OF PLASMAS VOLUME 10, NUMBER 6 JUNE 2003 J. E. Maggs a) and G. J. Morales Physics and Astronomy Department, University of California, Los Angeles, Los Angeles, California 90095 Received 17 December

More information

Near-Surface Cusp Confinement of Micro-Scale Plasma, Richard Wirz

Near-Surface Cusp Confinement of Micro-Scale Plasma, Richard Wirz Motivation Motivation / Objectives Ring cusp discharges provide highly efficient plasma thrusters Development of an efficient microdischarge (~ cm) large delta-v missions using small spacecraft formation

More information

Basics of electron beam-plasma interactions; experiment and simulation

Basics of electron beam-plasma interactions; experiment and simulation Basics of electron beam-plasma interactions; experiment and simulation Rod Boswell http://sp3.anu.edu.au Space Plasma Power and Propulsion Research School of Physics and Engineering The Australian National

More information

G.H. Share, W.N. Johnson, J.D. Kurfess, R.J. Murphy. A. Connors. B.L. Dingus, B.E. Schaefer. W. Collmar, V. Schonfelder

G.H. Share, W.N. Johnson, J.D. Kurfess, R.J. Murphy. A. Connors. B.L. Dingus, B.E. Schaefer. W. Collmar, V. Schonfelder COMPARISON OF BATSE, COMPTEL, EGRET, AND SPECTRA OF GRB 910601 G.H. Share, W.N. Johnson, J.D. Kurfess, R.J. Murphy E.O. Hulburt Center for Space Research, Naval Research Laboratory, Washington, DC 20375,

More information

Equilibrium Evolution in the ZaP Flow Z-Pinch

Equilibrium Evolution in the ZaP Flow Z-Pinch Equilibrium Evolution in the ZaP Flow Z-Pinch U. Shumlak, B.A. Nelson, C.S. Adams, D.J. Den Hartog, R.P. Golingo, S. L. Jackson, S.D. Knecht, J. Pasko, and D.T. Schmuland University of Washington, Seattle

More information

Plasma Diagnostics in an Applied Field MPD Thruster * #

Plasma Diagnostics in an Applied Field MPD Thruster * # Plasma Diagnostics in an Applied Field MPD Thruster * # G. Serianni, N. Vianello, F. Paganucci, P. Rossetti, V. Antoni, M. Bagatin, M. Andrenucci Consorzio RFX, Associazione Euratom-ENEA sulla Fusione

More information

I ABB NAVAL RESEARC LAB WAHINGTON DC F/S 18/1

I ABB NAVAL RESEARC LAB WAHINGTON DC F/S 18/1 I ABB NAVAL RESEARC LAB WAHINGTON DC F/S 18/1.TAB-LI.TY OF.ETA LIITED THERMONUCLEAR BURNIUI IJAN BC E OTT, A MAHIE I UNCLASSIFIED, NRL-MR-4156 SBIE -AD-ElO 38 NL SECURITY CL AS-SIFICATION o Tsb PAGE "WAo

More information

AIAA Low-Temperature Supersonic Boundary Layer Control Using Repetitively Pulsed MHD Forcing. Munetake Nishihara, Naibo Jiang,

AIAA Low-Temperature Supersonic Boundary Layer Control Using Repetitively Pulsed MHD Forcing. Munetake Nishihara, Naibo Jiang, AIAA 2005-5178 Low-Temperature Supersonic Boundary Layer Control Using Repetitively Pulsed MHD Forcing Munetake Nishihara, Naibo Jiang, J. William Rich, Walter R. Lempert, Igor V. Adamovich Dept. of Mechanical

More information

Effect of negative ions on the characteristics of plasma in a cylindrical discharge

Effect of negative ions on the characteristics of plasma in a cylindrical discharge Araghi and Dorranian Journal of Theoritical and Applied Physics 2013, 7:41 RESEARCH Open Access Effect of negative ions on the characteristics of plasma in a cylindrical discharge Farnaz Araghi and Davoud

More information

Copyright 1996, by the author(s). All rights reserved.

Copyright 1996, by the author(s). All rights reserved. Copyright 1996, by the author(s). All rights reserved. Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are

More information

Using a Microwave Interferometer to Measure Plasma Density Mentor: Prof. W. Gekelman. P. Pribyl (UCLA)

Using a Microwave Interferometer to Measure Plasma Density Mentor: Prof. W. Gekelman. P. Pribyl (UCLA) Using a Microwave Interferometer to Measure Plasma Density Avital Levi Mentor: Prof. W. Gekelman. P. Pribyl (UCLA) Introduction: Plasma is the fourth state of matter. It is composed of fully or partially

More information

GA A23736 EFFECTS OF CROSS-SECTION SHAPE ON L MODE AND H MODE ENERGY TRANSPORT

GA A23736 EFFECTS OF CROSS-SECTION SHAPE ON L MODE AND H MODE ENERGY TRANSPORT GA A3736 EFFECTS OF CROSS-SECTION SHAPE ON L MODE AND H MODE ENERGY TRANSPORT by T.C. LUCE, C.C. PETTY, and J.E. KINSEY AUGUST DISCLAIMER This report was prepared as an account of work sponsored by an

More information

Review of Micro-Propulsion Ablative Devices

Review of Micro-Propulsion Ablative Devices Review of Micro-Propulsion Ablative Devices Michael Keidar and Iain D. Boyd Aerospace Engineering, University of Michigan Ann Arbor 48109 USA Funded by Air Force Office of Scientific Research through grant

More information

Equilibrium Evolution in the ZaP Flow Z-Pinch

Equilibrium Evolution in the ZaP Flow Z-Pinch 1 IC/P7-11 Equilibrium Evolution in the ZaP Flow Z-Pinch U. Shumlak, C.S. Adams, R.P. Golingo, D.J. Den Hartog, S.L. Jackson, S. D. Knecht, K. A. Munson, B.A. Nelson, ZaP Team Aerospace & Energetics Research

More information

arxiv: v2 [physics.plasm-ph] 22 Mar 2017

arxiv: v2 [physics.plasm-ph] 22 Mar 2017 Generalized lower-hybrid mode with, density gradient, equilibrium ExB drift, collisions and finite electron Larmor radius: Numerical studies with MATLAB solver. Ivan Romadanov, Andrei Smolyakov, Winston

More information

Scattering in Cold- Cathode Discharges

Scattering in Cold- Cathode Discharges Simulating Electron Scattering in Cold- Cathode Discharges Alexander Khrabrov, Igor Kaganovich*, Vladimir I. Demidov**, George Petrov*** *Princeton Plasma Physics Laboratory ** Wright-Patterson Air Force

More information

Flow and dynamo measurements in the HIST double pulsing CHI experiment

Flow and dynamo measurements in the HIST double pulsing CHI experiment Innovative Confinement Concepts (ICC) & US-Japan Compact Torus (CT) Plasma Workshop August 16-19, 211, Seattle, Washington HIST Flow and dynamo measurements in the HIST double pulsing CHI experiment M.

More information

I M P O R T A N T S A F E T Y I N S T R U C T I O N S W h e n u s i n g t h i s e l e c t r o n i c d e v i c e, b a s i c p r e c a u t i o n s s h o

I M P O R T A N T S A F E T Y I N S T R U C T I O N S W h e n u s i n g t h i s e l e c t r o n i c d e v i c e, b a s i c p r e c a u t i o n s s h o I M P O R T A N T S A F E T Y I N S T R U C T I O N S W h e n u s i n g t h i s e l e c t r o n i c d e v i c e, b a s i c p r e c a u t i o n s s h o u l d a l w a y s b e t a k e n, i n c l u d f o l

More information

Formation of High-b ECH Plasma and Inward Particle Diffusion in RT-1

Formation of High-b ECH Plasma and Inward Particle Diffusion in RT-1 J Fusion Energ (2010) 29:553 557 DOI 10.1007/s10894-010-9327-6 ORIGINAL RESEARCH Formation of High-b ECH Plasma and Inward Particle Diffusion in RT-1 H. Saitoh Z. Yoshida J. Morikawa Y. Yano T. Mizushima

More information

Effect of parallel velocity shear on the excitation of electrostatic ion cyclotron waves

Effect of parallel velocity shear on the excitation of electrostatic ion cyclotron waves 4 February 2002 Physics Letters A 293 (2002) 260 265 www.elsevier.com/locate/pla Effect of parallel velocity shear on the excitation of electrostatic ion cyclotron waves E.P. Agrimson, N. D Angelo, R.L.

More information

DTIC. I STRBUTION ffa-temmen- A 90) < PLASMA STUDIES CORNELL UNIVERSITY. Nq LABORATORY OF ITHACA, NEW YORK .ELECTE APR

DTIC. I STRBUTION ffa-temmen- A 90) < PLASMA STUDIES CORNELL UNIVERSITY. Nq LABORATORY OF ITHACA, NEW YORK .ELECTE APR LD 0 eq" NU Nq LABORATORY OF < PLASMA STUDIES intense Proton Beam Plasma Interactions R. Kraft and B. R. Kusse Laboratory of Plasma Studies Cornell University Ithaca, New York 14853 LPS 326 November 1983

More information

Experimental study of classical heat transport in a magnetized plasma

Experimental study of classical heat transport in a magnetized plasma PHYSICS OF PLASMAS VOLUME 7, NUMBER 2 FEBRUARY 2000 Experimental study of classical heat transport in a magnetized plasma A. T. Burke, J. E. Maggs, and G. J. Morales Department of Physics and Astronomy,

More information

Experimental Studies of Ion Beam Neutralization: Preliminary Results

Experimental Studies of Ion Beam Neutralization: Preliminary Results Experimental Studies of Ion Beam Neutralization: Preliminary Results N. Ding, J. Polansky, R. Downey and J. Wang Department of Astronautical Engineering University of Southern California Los Angeles, CA

More information

Abstract. Objectives. Theory

Abstract. Objectives. Theory A Proposal to Develop a Two-Stage Gridless Ion Thruster with Closed Electron Drift Richard R. Hofer Plasmadynamics and Electric Propulsion Laboratory (PEPL) Department of Aerospace Engineering University

More information

Nitrogen Glow Discharge by a DC Virtual Cathode

Nitrogen Glow Discharge by a DC Virtual Cathode Nitrogen Glow Discharge by a DC Virtual Cathode Azza M. Shager a, Amany T. Sroor b, Hoda A. El Tayeb a, Hoda A. El Gamal a, and Mohamed M. Masoud a a Plasma Physics and Nuclear Fusion Department, Atomic

More information

Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave

Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave Destruction of a Magnetic Mirror-Trapped Hot Electron Ring by a shear Alfven Wave Y. Wang 1, W. Gekelman 1, P. Pribyl 1, D. Papadopoulos 2 1 University of California, Los Angeles 2 University of Maryland,

More information

Electron Trapping in High-Current Ion Beam Pipes

Electron Trapping in High-Current Ion Beam Pipes SLAC-PUB-8367 March 2000 Electron Trapping in High-Current Ion Beam Pipes W. B. Herrmannsfeldt Contributed to 13th Internation Symposium on Heavy Ion Inertial Fusion, 3/13/2000-3/17/2000, San Diego, CA,

More information

Cassini observations of the thermal plasma in the vicinity of Saturn s main rings and the F and G rings

Cassini observations of the thermal plasma in the vicinity of Saturn s main rings and the F and G rings GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L14S04, doi:10.1029/2005gl022690, 2005 Cassini observations of the thermal plasma in the vicinity of Saturn s main rings and the F and G rings R. L. Tokar, 1 R. E.

More information

Huashun Zhang. Ion Sources. With 187 Figures and 26 Tables Э SCIENCE PRESS. Springer

Huashun Zhang. Ion Sources. With 187 Figures and 26 Tables Э SCIENCE PRESS. Springer Huashun Zhang Ion Sources With 187 Figures and 26 Tables Э SCIENCE PRESS Springer XI Contents 1 INTRODUCTION 1 1.1 Major Applications and Requirements 1 1.2 Performances and Research Subjects 1 1.3 Historical

More information

PIC/MCC Simulation of Radio Frequency Hollow Cathode Discharge in Nitrogen

PIC/MCC Simulation of Radio Frequency Hollow Cathode Discharge in Nitrogen PIC/MCC Simulation of Radio Frequency Hollow Cathode Discharge in Nitrogen HAN Qing ( ), WANG Jing ( ), ZHANG Lianzhu ( ) College of Physics Science and Information Engineering, Hebei Normal University,

More information

Present status of 200keV polarized electron gun at Nagoya University

Present status of 200keV polarized electron gun at Nagoya University Present status of 200keV polarized electron gun at Nagoya University Nagoya University Masahiro Yamamoto, N. Yamamoto, T. Nakanishi, S. Okumi, F. Furuta, M. Miyamoto, M. Kuwahara, K. Naniwa, K. Yasui KEK

More information

An Experimental Study to Show the Effects of Secondary Electron Emission on Plasma Properties in Hall Thrusters

An Experimental Study to Show the Effects of Secondary Electron Emission on Plasma Properties in Hall Thrusters An Experimental Study to Show the Effects of Secondary Electron Emission on Plasma Properties in Hall Thrusters Kapil U. Sawlani and John E. Foster Plasma Science and Technology Laboratory Nuclear Engineering

More information

A comparison of emissive probe techniques for electric potential measurements in a Hall thruster plasma

A comparison of emissive probe techniques for electric potential measurements in a Hall thruster plasma A comparison of emissive probe techniques for electric potential measurements in a Hall thruster plasma J. P. Sheehan*, Y. Raitses**, N. Hershkowitz*, I. Kaganovich**, and N. J. Fisch** *University of

More information

Use precise language and domain-specific vocabulary to inform about or explain the topic. CCSS.ELA-LITERACY.WHST D

Use precise language and domain-specific vocabulary to inform about or explain the topic. CCSS.ELA-LITERACY.WHST D Lesson seven What is a chemical reaction? Science Constructing Explanations, Engaging in Argument and Obtaining, Evaluating, and Communicating Information ENGLISH LANGUAGE ARTS Reading Informational Text,

More information

Development of a High Intensity EBIT for Basic and Applied Science

Development of a High Intensity EBIT for Basic and Applied Science UCRL-ID- 129832 Development of a High Intensity EBIT for Basic and Applied Science R.E. Marrs D. Schneider February 5,1998 This is an informal report intended primarily for internal or limited external

More information

FINAL REPORT. DOE Grant DE-FG03-87ER13727

FINAL REPORT. DOE Grant DE-FG03-87ER13727 FINAL REPORT DOE Grant DE-FG03-87ER13727 Dynamics of Electronegative Plasmas for Materials Processing Allan J. Lichtenberg and Michael A. Lieberman Department of Electrical Engineering and Computer Sciences

More information

176 5 t h Fl oo r. 337 P o ly me r Ma te ri al s

176 5 t h Fl oo r. 337 P o ly me r Ma te ri al s A g la di ou s F. L. 462 E l ec tr on ic D ev el op me nt A i ng er A.W.S. 371 C. A. M. A l ex an de r 236 A d mi ni st ra ti on R. H. (M rs ) A n dr ew s P. V. 326 O p ti ca l Tr an sm is si on A p ps

More information

INFLUENCE OF STATIC, RADIAL ELECTRIC FIELDS O N TRAPPED PARTICLE INSTABILITIES IN TOROIDAL SYSTEMS

INFLUENCE OF STATIC, RADIAL ELECTRIC FIELDS O N TRAPPED PARTICLE INSTABILITIES IN TOROIDAL SYSTEMS IC/66/100 INTERNATIONAL ATOMIC ENERGY AGENCY INTERNATIONAL CENTRE FOR THEORETICAL PHYSICS INFLUENCE OF STATIC, RADIAL ELECTRIC FIELDS O N TRAPPED PARTICLE INSTABILITIES IN TOROIDAL SYSTEMS A. A. GALEEV

More information

Improvement of Propulsion Performance by Gas Injection and External Magnetic Field in Electrodeless Plasma Thrusters

Improvement of Propulsion Performance by Gas Injection and External Magnetic Field in Electrodeless Plasma Thrusters Improvement of Propulsion Performance by Gas Injection and External Magnetic Field in Electrodeless Plasma Thrusters IEPC-217-249 Presented at the th International Electric Propulsion Conference Georgia

More information

MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges

MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges MHD Analysis of the Tokamak Edge Pedestal in the Low Collisionality Regime Thoughts on the Physics of ELM-free QH and RMP Discharges P.B. Snyder 1 Contributions from: H.R. Wilson 2, D.P. Brennan 1, K.H.

More information

Diffusion of Arc Plasmas across a Magnetic Field

Diffusion of Arc Plasmas across a Magnetic Field P366 USA Diffusion of Arc Plasmas across a Magnetic Field By Albert Simon* The effect of a magnetic field В is to reduce the coefficients of diffusion, ) p, across the magnetic field to the values equations

More information

PFC/JA NEUTRAL BEAM PENETRATION CONSIDERATIONS FOR CIT

PFC/JA NEUTRAL BEAM PENETRATION CONSIDERATIONS FOR CIT PFC/JA-88-12 NEUTRAL BEAM PENETRATION CONSIDERATIONS FOR CIT J. Wei, L. Bromberg, R. C. Myer, and D. R. Cohn Plasma Fusion Center Massachusetts Institute of Technology Cambridge, Massachusetts 2139 To

More information

PHYSICAL VAPOR DEPOSITION OF THIN FILMS

PHYSICAL VAPOR DEPOSITION OF THIN FILMS PHYSICAL VAPOR DEPOSITION OF THIN FILMS JOHN E. MAHAN Colorado State University A Wiley-Interscience Publication JOHN WILEY & SONS, INC. New York Chichester Weinheim Brisbane Singapore Toronto CONTENTS

More information

Enhancement of an IEC Device with a Helicon Ion Source for Helium-3 Fusion

Enhancement of an IEC Device with a Helicon Ion Source for Helium-3 Fusion Enhancement of an IEC Device with a Helicon Ion Source for Helium-3 Fusion Gabriel E. Becerra*, Gerald L. Kulcinski and John F. Santarius Fusion Technology Institute University of Wisconsin Madison *E-mail:

More information

Helicon Plasma Thruster Experiment Controlling Cross-Field Diffusion within a Magnetic Nozzle

Helicon Plasma Thruster Experiment Controlling Cross-Field Diffusion within a Magnetic Nozzle Helicon Plasma Thruster Experiment Controlling Cross-Field Diffusion within a Magnetic Nozzle IEPC-2013-163 Presented at the 33rd International Electric Propulsion Conference, The George Washington University

More information

Effects of the Gas Pressure on Low Frequency Oscillations in E B Discharges

Effects of the Gas Pressure on Low Frequency Oscillations in E B Discharges Effects of the Gas Pressure on Low Frequency Oscillations in E B Discharges IEPC-2015-307 /ISTS-2015-b-307 Presented at Joint Conference of 30th International Symposium on Space Technology and Science

More information