ИСТИНА

Relativistic intensity femtosecond laser plasma is a brilliant source of ultra-short bursts of high energy electrons, ions, hard X- and γ-rays which can be used to excite isomeric nuclear levels. Usually, when using a laser plasma, direct isomeric levels excitation is considered due to mechanisms such as photoexcitation, inelastic electrons and ions scattering, nuclear excitation by electron capture (NEEC), nuclear excitation by electron transfer (NEET) etc. This assumes the use of low-energy (10-100 keV) X-ray quanta, electrons or ions. In this work, we present a theoretical analysis of the efficiency for various excitation mechanisms using high-energy plasma radiation (> 1 MeV). It was shown that for the 9.4 and 41.6 keV levels of the 83Kr nucleus, the indirect excitation scheme through short-lived levels with energies of 0.5–1.5 MeV is more efficient. Experimental schemes are proposed based on Kr cluster jet or high-pressure Kr chamber and solid target irradiated by relativistic femtosecond laser.