During transient instabilities in a 2 eV, highly collisional MHD-driven plasma jet experiment, evidence of a 6 keV electron tail was observed via x-ray measurements. The cause for this unexpected high energy tail is explored using numerical simulations of the Rutherford scattering of a large number of electrons and ions in the presence of a uniform electric field that is abruptly turned on as in the experiment. When the only active processes are Rutherford scattering and acceleration by the electric field, contrary to the classical Fokker–Planck theory of plasma resistivity, it is found that no steady state develops, and instead, the particle kinetic energy increases continuously. However, when a power loss mechanism is introduced mimicking atomic line radiation, a near steady state can develop and, in this case, an energetic electron tail similar to that observed in the experiment can develop. The reasons underlying this behavior are analyzed, and it is shown that an important consideration is that Rutherford scattering is dominated by the cumulative effect of grazing collisions, whereas atomic line radiation requires an approximately direct rather than a grazing collision.

1.
R. S.
Marshall
,
M. J.
Flynn
, and
P. M.
Bellan
,
Phys. Plasmas
25
,
112101
(
2018
).
2.
R. S.
Marshall
and
P. M.
Bellan
,
Phys. Plasmas
26
,
042102
(
2019
).
3.
M. J.
Aschwanden
,
Space Sci. Rev.
101
,
1
(
2002
).
4.
W. G.
Pilipp
,
H.
Miggenrieder
,
M. D.
Montgomery
,
K. H.
Mühlhäuser
,
H.
Rosenbauer
, and
R.
Schwenn
,
J. Geophys. Res.
92
,
1075
, https://doi.org/10.1029/JA092iA02p01075 (
1987
).
5.
F.
Fiuza
,
G. F.
Swadling
,
A.
Grassi
,
H. G.
Rinderknecht
,
D. P.
Higginson
,
D. D.
Ryutov
,
C.
Bruulsema
,
R. P.
Drake
,
S.
Funk
,
S.
Glenzer
,
G.
Gregori
,
C. K.
Li
,
B. B.
Pollock
,
B. A.
Remington
,
J. S.
Ross
,
W.
Rozmus
,
Y.
Sakawa
,
A.
Spitkovsky
,
S.
Wilks
, and
H.-S.
Park
,
Nat. Phys.
16
,
916
(
2020
).
6.
D. F.
da Cruz
,
A. G.
Peeters
,
A. J. H.
Donne
,
N. J. L.
Cardozo
, and
E.
Westerhof
,
Plasma Phys. Controlled Fusion
35
,
693
(
1993
).
7.
Y.
Zhou
and
P. M.
Bellan
,
Phys. Plasmas
30
,
052101
(
2023
).
8.
S.
You
,
G. S.
Yun
, and
P. M.
Bellan
,
Phys. Rev. Lett.
95
,
045002
(
2005
).
9.
P. M.
Bellan
,
Phys. Plasmas
25
,
055601
(
2018
).
10.
A. L.
Moser
and
P. M.
Bellan
,
Nature
482
,
379
(
2012
).
11.
O.
Buneman
,
Phys. Rev. Lett.
1
,
8
(
1958
).
12.
H.
Dreicer
,
Phys. Rev.
117
,
329
(
1960
).
13.
R. M.
Kulsrud
,
Y.-C.
Sun
,
N. K.
Winsor
, and
H. A.
Fallon
,
Phys. Rev. Lett.
31
,
690
(
1973
).
14.
T.
Takizuka
and
H.
Abe
,
J. Comput. Phys.
25
,
205
(
1977
).
15.
T. D.
Arber
,
K.
Bennett
,
C. S.
Brady
,
A.
Lawrence-Douglas
,
M. G.
Ramsay
,
N. J.
Sircombe
,
P.
Gillies
,
R. G.
Evans
,
H.
Schmitz
,
A. R.
Bell
, and
C. P.
Ridgers
,
Plasma Phys. Controlled Fusion
57
,
113001
(
2015
).
16.
S. I.
Braginskii
,
Sov. Phys. JETP
6
,
358
(
1958
).
17.
S.
Chandrasekhar
,
Astrophys. J.
97
,
255
(
1943
).
18.
R. S.
Cohen
,
L.
Spitzer
, and
P. M.
Routly
,
Phys. Rev.
80
,
230
(
1950
).
19.
L.
Spitzer
and
R.
Härm
,
Phys. Rev.
89
,
977
(
1953
).
20.
B. A.
Trubnikov
,
Rev. Plasma Phys.
1
,
105
(
1965
).
21.
N. A.
Krall
and
A. W.
Trivelpiece
,
Principles of Plasma Physics
, International Series in Pure and Applied Physics (
McGraw-Hill
,
1973
).
22.
P. M.
Bellan
,
Fundamentals of Plasma Physics
(
Cambridge University Press
,
Cambridge
,
2006
).
23.
K.
Nanbu
,
Phys. Rev. E
55
,
4642
(
1997
).
24.
J.
Connor
and
R.
Hastie
,
Nucl. Fusion
15
,
415
(
1975
).
25.
M.
Landreman
and
D. R.
Ernst
,
J. Comput. Phys.
243
,
130
(
2013
).
26.
Y.
Zhang
,
S.
Pree
, and
P. M.
Bellan
,
Nat. Astron.
7
,
663
(
2023
).
27.
E. E.
Trofimovich
and
V. P.
Krainov
,
Sov. Phys. JETP
75
,
27
(
1992
).
28.
D.
Nicholson
,
Introduction to Plasma Theory
(
Wiley
,
1983
).
29.
R.
Goldston
and
P. H.
Rutherford
,
Introduction to Plasma Physics
(
Institute of Physics
,
Bristol
,
1995
).
30.
G.
Lantoine
and
R. P.
Russell
,
Celestial Mech. Dyn. Astron.
109
,
333
(
2011
).
31.
J. B.
Boffard
,
G. A.
Piech
,
M. F.
Gehrke
,
L. W.
Anderson
, and
C. C.
Lin
,
Phys. Rev. A
59
,
2749
(
1999
).
32.
C.
Fa-Yin
and
S.
Bing-Ren
,
Chin. Phys.
16
,
3458
(
2007
).
33.
K.
Miyamoto
,
Plasma Physics for Nuclear Fusion
,
Revised edition
(
MIT Press
,
Cambridge
,
1989
).
34.
H.
Knoepfel
and
D.
Spong
,
Nucl. Fusion
19
,
785
(
1979
).
35.
B. N.
Breizman
,
P.
Aleynikov
,
E. M.
Hollmann
, and
M.
Lehnen
,
Nucl. Fusion
59
,
083001
(
2019
).
36.
K.-B.
Chai
,
X.
Zhai
, and
P. M.
Bellan
,
Phys. Plasmas
23
,
032122
(
2016
).
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