Effect of the plasma density scale length on the direction of fast electrons in relativistic laser-solid interactions
The angular distribution of bremsstrahlung gamma rays produced by fast electrons accelerated in relativistic laser-solid interaction has been studied by photoneutron activation in copper. We show that the gamma-ray beam moves from the target normal to the direction of the k(laser) vector as the scale length is increased. Similar behavior is found also in 2D particle-in-cell simulations.
Santala
MI
Plasma Physics Group, The Blackett Laboratory, Imperial College, London SW7 2BZ, United Kingdom.
Zepf
M
Watts
I
Beg
FN
Clark
E
Tatarakis
M
Krushelnick
K
Dangor
AE
McCanny
T
Spencer
I
Singhal
RP
Ledingham
KW
Wilks
SC
Machacek
AC
Wark
JS
Allott
R
Clarke
RJ
Norreys
PA