Study of x-ray emission enhancement via a high-contrast femtosecond laser interacting with a solid foil.
We observed the increase of the conversion efficiency from laser energy to Kalpha x-ray energy (eta(K)) produced by a 60 fs frequency doubled high-contrast laser pulse focused on a Cu foil, compared to the case of the fundamental laser pulse. eta(K) shows a strong dependence on the nonlinearly modified rising edge of the laser pulse. It reaches a maximum for a 100 fs negatively modified pulse. The hot electron efficient heating leads to the enhancement of eta(K). This demonstrates that high-contrast lasers are an effective tool for optimizing eta(K), via increasing the hot electrons by vacuum heating.
Chen
L M
LM
Advanced Photon Research Center, Kansai Photon Science Institute, JAEA, Kyoto 619-0215, Japan.
Kando
M
M
Xu
M H
MH
Li
Y T
YT
Koga
J
J
Chen
M
M
Xu
H
H
Yuan
X H
XH
Dong
Q L
QL
Sheng
Z M
ZM
Bulanov
S V
SV
Kato
Y
Y
Zhang
J
J
Tajima
T
T