ИСТИНА

Laser acceleration of electrons in plasma waves allows achieving record values of the accelerating field of 1–100GV/m, exceeding the limiting values for classical accelerators. Gas clusters can effectively inject electrons into a plasma wave under laser irradiation with relativistic intensity (I >10^18 W/cm2). It is considered that efficient injection will occur when the electrons leave the cluster during laser exposure. We propose using oxygen, nitrogen, argon in the low-pressure mode and minimal cluster size as a laser target. This made it possible to obtain a stable, narrow (5–10 mrad) electron beam with a charge of tens of pC and a thermal spectrum with E = 4MeV. The best e-beam divergence (5 mrad) with sufficient charge (up to 30 pC) was obtained in gases with the lowest atomic number. Electron beam properties are consistent with a bubble or SMLWFA acceleration regime. The results are relevant for obtaining betatron X-ray, bremsstrahlung gamma radiation flash-therapy studies with an electron bunch with a large charge and a short duration.