Nonlinear increase of X-ray intensities from thin foils irradiated with a 200 TW femtosecond laser.
We report, for the first time, that the energy of femtosecond optical laser pulses, E, with relativistic intensities I > 10(21)  W/cm(2) is efficiently converted to X-ray radiation, which is emitted by "hot" electron component in collision-less processes and heats the solid density plasma periphery. As shown by direct high-resolution spectroscopic measurements X-ray radiation from plasma periphery exhibits unusual non-linear growth ~E(4-5) of its power. The non-linear power growth occurs far earlier than the known regime when the radiation reaction dominates particle motion (RDR). Nevertheless, the radiation is shown to dominate the kinetics of the plasma periphery, changing in this regime (now labeled RDKR) the physical picture of the laser plasma interaction. Although in the experiments reported here we demonstrated by observation of KK hollow ions that X-ray intensities in the keV range exceeds ~10(17)  W/cm(2), there is no theoretical limit of the radiation power. Therefore, such powerful X-ray sources can produce and probe exotic material states with high densities and multiple inner-shell electron excitations even for higher Z elements. Femtosecond laser-produced plasmas may thus provide unique ultra-bright X-ray sources, for future studies of matter in extreme conditions, material science studies, and radiography of biological systems.
Institute for Academic Initiatives, Osaka University, Suita, Osaka, 565-0871, Japan.|Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia.
A Ya
AY
Faenov
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
J
J
Colgan
Sandia National Laboratories, Albuquerque, New Mexico 87123, USA.
S B
SB
Hansen
PPC and Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
A
A
Zhidkov
Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia.|PPC and Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
T A
TA
Pikuz
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
M
M
Nishiuchi
Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia.|National Research Nuclear University (MEPhI), Moscow 115409, Russia.
S A
SA
Pikuz
Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412, Russia.|National Research Nuclear University (MEPhI), Moscow 115409, Russia.
I Yu
IY
Skobelev
Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
J
J
Abdallah
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
H
H
Sakaki
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
A
A
Sagisaka
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
A S
AS
Pirozhkov
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
K
K
Ogura
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
Y
Y
Fukuda
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
M
M
Kanasaki
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
N
N
Hasegawa
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
M
M
Nishikino
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
M
M
Kando
Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Japan.
Y
Y
Watanabe
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
T
T
Kawachi
PPC and Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
S
S
Masuda
PPC and Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
T
T
Hosokai
Institute for Academic Initiatives, Osaka University, Suita, Osaka, 565-0871, Japan.|PPC and Graduate School of Engineering, Osaka University, 2-1, Yamadaoka, Suita, Osaka 565-0871, Japan.
R
R
Kodama
Quantum Beam Science Directorate, Japan Atomic Energy Agency, Kizugawa, Kyoto, Japan.
K
K
Kondo