Ponderomotive acceleration of electrons by a short laser pulse undergoing relativistic self-focusing in a plasma is investigated. The saturation in nonlinear plasma permittivity causes periodic self-focusing of the laser. The periodicity lengths are different for different axial segments of the pulse. As a result, pulse shape is distorted. An electron initially on the laser axis and at the front of the self-focusing pulse gains energy from the pulse until it is run over by the pulse peak. By the time electron reaches the tail, if pulse begins diverging, the deceleration of the electron is slower and the electron is left with net energy gain. The electrons slightly off the laser axis see a radial ponderomotive force too. Initially, when they are accelerated by the pulse front the acceleration is strong as they are closer to the axis. When they see the tail of the pulse (after being run by the pulse), they are farther from the axis and the retardation ponderomotive force is weaker. Thus, there is net energy gain.

1.
T.
Tajima
and
J. M.
Dawson
,
Phys. Rev. Lett.
43
,
267
(
1979
).
2.
D.
Umstadter
,
S. -Y.
Chen
,
A.
Maksimchuk
,
G.
Mourou
, and
R.
Wagner
,
Science
273
,
472
(
1996
);
[PubMed]
D.
Umstadter
,
J.
Kim
,
E.
Esarey
,
E.
Dodd
, and
T.
Neubert
,
Phys. Rev. E
51
,
3484
(
1995
).
3.
R.
Wagner
,
S. -Y.
Chen
,
A.
Maksimghuk
, and
D.
Umstadter
,
Phys. Rev. Lett.
78
,
3125
(
1997
).
4.
P.
Sprangle
,
E.
Esarey
, and
J.
Krall
,
Phys. Plasmas
3
,
2183
(
1996
).
5.
H.
Suk
,
N.
Barov
,
J. B.
Rosenzweig
, and
E.
Esarey
,
Phys. Rev. Lett.
86
,
1011
(
2001
).
6.
C.
Gahn
,
G. D.
Tsakiris
,
A.
Pukhov
,
J.
Meyer-ter-Vehn
,
G.
Pretzler
,
P.
Thirolf
,
D.
Habs
, and
K. J.
Witte
,
Phys. Rev. Lett.
83
,
4772
(
1999
).
7.
C. J.
McKinstrie
and
E. A.
Startsev
,
Phys. Rev. E
54
,
R1070
(
1996
).
8.
J. H.
Rogers
and
D. Q.
Hwang
,
Phys. Rev. Lett.
68
,
3877
(
1992
).
9.
K. K.
Magesh Kumar
and
V. K.
Tripathi
,
Phys. Plasmas
17
,
053103
(
2010
).
10.
T.
Katsouleas
and
J. M.
Dawson
,
Phys. Rev. Lett.
51
,
392
(
1983
).
11.
V.
Sazegari
,
M.
Mirzaie
, and
B.
Shokri
,
Phys. Plasmas
13
,
033102
(
2006
).
12.
A.
Sharma
and
V. K.
Tripathi
,
Phys. Plasmas
16
,
043103
(
2009
).
13.
R.
Singh
,
A. K.
Sharma
, and
V. K.
Tripathi
,
Laser Part. Beams
28
,
299
(
2010
).
14.
A. V.
Sofronov
and
V. P.
Krainov
,
J. Phys. B
37
,
L329
(
2004
).
15.
F. V.
Hartemann
,
S. N.
Fochs
,
G. P.
Le Sage
,
N. C.
Luhmann
,
J. G.
Woodworth
,
M. D.
Perry
,
Y. J.
Chen
, and
A. K.
Kermen
,
Phys. Rev. E
51
,
4833
(
1995
).
16.
C. S.
Liu
and
V. K.
Tripathi
,
Phys. Plasmas
12
,
043103
(
2005
).
17.
F.
He
,
W.
Yu
,
P.
Lu
,
H.
Xu
,
L.
Qian
,
B.
Shen
,
X.
Yuan
,
R.
Li
, and
Z.
Xu
,
Phys. Rev. E
68
,
046407
(
2003
).
18.
R.
Singh
and
A. K.
Sharma
,
Appl. Phys. B: Lasers Opt.
100
,
535
(
2010
).
19.
G.
Malka
,
E.
Lefebvre
, and
J. L.
Miquel
,
Phys. Rev. Lett.
78
,
3314
(
1997
).
20.
A.
Pukhov
and
J.
Meyer-ter-Vehn
,
Phys. Rev. Lett.
76
,
3975
(
1996
).
21.
G. D.
Tsakiris
,
C.
Gahn
, and
V. K.
Tripathi
,
Phys. Plasmas
7
,
3017
(
2000
).
22.
C. S.
Liu
and
V. K.
Tripathi
,
J. Opt. Soc. Am.
18
,
1714
(
2001
).
23.
D.
Umstadter
,
J. K.
Kim
, and
E.
Dodd
,
Phys. Rev. Lett.
76
,
2073
(
1996
).
24.
E.
Esarey
,
R. F.
Hubbard
,
W. P.
Leemans
,
A.
Ting
, and
P.
Sprangle
,
Phys. Rev. Lett.
79
,
2682
(
1997
).
25.
T. P.
Rowlands-Rees
,
C.
Kamperidis
,
S.
Kneip
,
A. J.
Gonsalves
,
S. P. D.
Mangles
,
J. G.
Gallacher
,
E.
Brunetti
,
T.
Ibbotson
,
C. D.
Murphy
,
P. S.
Foster
,
M. J. V.
Streeter
,
F.
Budde
,
P. A.
Norreys
,
D. A.
Jaroszynski
,
K.
Krushelnick
,
Z.
Najmudin
, and
S. M.
Hooker
,
Phys. Rev. Lett.
100
,
105005
(
2008
).
26.
A. G.
Khachatryan
,
Phys. Rev. E
65
,
046504
(
2002
).
27.
S.
Bulanov
,
N.
Naumova
,
F.
Pegoraro
, and
J.
Sakai
,
Phys. Rev. E
58
,
R5257
(
1998
).
28.
C. B.
Schroeder
,
P. B.
Lee
,
J. S.
Wurtele
,
E.
Esarey
, and
W. P.
Leemans
,
Phys. Rev. E
59
,
6037
(
1999
).
29.
K.
Nagashima
,
Y.
Kishimoto
, and
H.
Takuma
,
Phys. Rev. E
59
,
1263
(
1999
).
30.
V.
Vshivkov
,
N.
Naumova
,
F.
Pegoraro
, and
S.
Bulanov
,
Nucl. Instrum. Methods Phys. Res. A
410
,
493
(
1998
).
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