TY  - JOUR
A1  - Rosmej, Olga N.
A1  - Shen, Xiaofei
A1  - Pukhov, Alexander
A1  - Antonelli, Luca
A1  - Barbato, Francesco
A1  - Gyrdymov, Mikhail
A1  - Günther, Marc M.
A1  - Zähter, Şêro Jakob
A1  - Popov, Vyacheslav S.
A1  - Borisenko, Nataliya G.
A1  - Andreev, Nikolay E.
T1  - Bright betatron radiation from direct-laser-accelerated electrons at moderate relativistic laser intensity
T2  - Matter and radiation at extremes
N2  - Direct laser acceleration (DLA) of electrons in a plasma of near-critical electron density (NCD) and the associated synchrotron-like radiation are discussed for moderate relativistic laser intensity (normalized laser amplitude a0 ≤ 4.3) and ps length pulse. This regime is typical of kJ PW-class laser facilities designed for high-energy-density (HED) research. In experiments at the PHELIX facility, it has been demonstrated that interaction of a 1019 W/cm2 sub-ps laser pulse with a sub-mm length NCD plasma results in the generation of high-current well-directed super-ponderomotive electrons with an effective temperature ten times higher than the ponderomotive potential [Rosmej et al., Plasma Phys. Controlled Fusion 62, 115024 (2020)]. Three-dimensional particle-in-cell simulations provide good agreement with the measured electron energy distribution and are used in the current work to study synchrotron radiation from the DLA-accelerated electrons. The resulting x-ray spectrum with a critical energy of 5 keV reveals an ultrahigh photon number of 7 × 1011 in the 1–30 keV photon energy range at the focused laser energy of 20 J. Numerical simulations of betatron x-ray phase contrast imaging based on the DLA process for the parameters of a PHELIX laser are presented. The results are of interest for applications in HED experiments, which require a ps x-ray pulse and a high photon flux.
KW  - X-ray phase contrast imaging
KW  - Betatrons
KW  - Plasma acceleration
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/62822
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-628223
SN  - 2468-080X
N1  - This work was also supported by the DFG (Project No. PU 213/9), EPSRC Grant No. EP/P026796/1.
VL  - 6
IS  - 4, art. 048401
SP  - 1
EP  - 8
PB  - AIP Publishing
CY  - Melville, NY
ER  -