Open AccessHigh-current laser-driven beams of relativistic electrons for high energy density research
Author(s) -
O. Rosmej,
M. Gyrdymov,
M. Günther,
N. E. Andreev,
P. Tavana,
P. Neumayer,
Ş. Zähter,
Nadine Zahn,
В. С. Попов,
Н. Г. Борисенко,
А. В. Канцырев,
A. V. Skobliakov,
V. A. Panyushkin,
A. V. Bogdanov,
F. Consoli,
X. F. Shen,
A. Pukhov
Publication year - 2020
Publication title -
plasma physics and controlled fusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.328
H-Index - 111
eISSN - 1361-6587
pISSN - 0741-3335
DOI - 10.1088/1361-6587/abb24e
Subject(s) - electron , bremsstrahlung , atomic physics , physics , laser , plasma , relativistic electron beam , inertial confinement fusion , nuclear physics , cathode ray , optics
We report on enhanced laser driven electron beam generation in the multi MeV energy range that promises a tremendous increase of the diagnostic potential of high energy sub-PW and PW-class laser systems. In the experiment, an intense sub-picosecond laser pulse of ∼10 19 Wcm −2 intensity propagates through a plasma of near critical electron density (NCD) and drives the direct laser acceleration (DLA) of plasma electrons. Low-density polymer foams were used for the production of hydrodynamically stable long-scale NCD-plasmas. Measurements show that relativistic electrons generated in the DLA-process propagate within a half angle of 1 2 ± 1° to the laser axis. Inside this divergence cone, an effective electron temperature of 10–13 MeV and a maximum of the electron energy of 100 MeV were reached. The high laser energy conversion efficiency into electrons with energies above 2 MeV achieved 23% with a total charge approaching 1 μ C. For application purposes, we used the nuclear activation method to characterize the MeV bremsstrahlung spectrum produced in the interaction of the high-current relativistic electrons with high-Z samples and measured top yields of gamma-driven nuclear reactions. The optimization of the high-Z target geometry predicts an ultra-high MeV photon number of ∼10 12 per shot at moderate relativistic laser intensity of 10 19 Wcm −2 . A good agreement between the experimental data and the results of the 3D-PIC and GEANT4-simulations was demonstrated.