Simulation of enhanced characteristic x rays from a 40-MeV electron beam laser accelerated in plasma

Autor: L. Nikzad, R. Sadighi-Bonabi, Z. Riazi, M. Mohammadi, F. Heydarian
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Physical Review Special Topics. Accelerators and Beams, Vol 15, Iss 2, p 021301 (2012)
Druh dokumentu: article
ISSN: 1098-4402
DOI: 10.1103/PhysRevSTAB.15.021301
Popis: Simulation of x-ray generation from bombardment of various solid targets by quasimonoenergetic electrons is considered. The electron bunches are accelerated in a plasma produced by interaction of 500 mJ, 30 femtosecond laser pulses with a helium gas jet. These relativistic electrons propagate in the ion channel generated in the wake of the laser pulse. A beam of MeV electrons can interact with targets to generate x-ray radiation with keV energy. The MCNP-4C code based on Monte Carlo simulation is employed to compare the production of bremsstrahlung and characteristic x rays between 10 and 100 keV by using two quasi-Maxwellian and quasimonoenergetic energy distributions of electrons. For a specific electron spectrum and a definite sample, the maximum x-ray flux varies with the target thickness. Besides, by increasing the target atomic number, the maximum x-ray flux is increased and shifted towards a higher energy level. It is shown that by using the quasimonoenergetic electron profile, a more intense x ray can be produced relative to the quasi-Maxwellian profile (with the same total energy), representing up to 77% flux enhancement at K_{α} energy.
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