Studies of x-ray emission from a laser induced vacuum discharge of moderate storage energy (<20 J) are examined. It is found that micropinches in the initial stage of the cathode jet expansion into the interelectrode gap are formed. Hot plasma of the micropinches emits a soft x-ray radiation and beams of accelerated electrons moving toward the anode. It is found that these phenomena occur just when both amplitude of the discharge current and energy of the initiating laser pulse lie in the specified ranges of values. The position of the micropinch within the interelectrode gap and also the intensity of the x-ray radiation and beams of the accelerated electrons emitted from the micropinch are variable over a wide range of values through changes in energy of the laser pulse and/or amplitude of the discharge current. The experimental results are compared with the data of the particle-in-cell simulations and a fair agreement is found between them.
Betatron radiation emitted during the direct laser acceleration of electrons in underdense plasmas