Diagnostic system to study sub-THz emission from open trap at strong beam-plasma interaction

Abstract

Neutral beam (NB) injector for the TCV tokamak has been designed to produce a deuterium beam with energy 30 keV, equivalent current up to 50 A, and pulse duration 2 s. The injector operation is accompanied by generation of fast neutrons produced in deuterium-deuterium collisions via a nuclear fusion reaction D(D,n)3He. Main sources of the neutrons are a beam neutralizer and a deuterium-saturated surface of beam dump. Measurements of the neutron yields from the both sources were produced on the prototype of TCV injector in the Budker Institute of Nuclear Physics. Neutron yields from neutralizer and beam dump are equal to 9.5x10 8 s −1 and 2.3x10 9 s −1 for the nominal parameters of the injector (30 kV, 50 A).

Highly efficient electromagnetic emission during 100 keV electron beam relaxation in a thin magnetized plasma

“…Generation of electromagnetic (EM) radiation in a plasma by an electron beam has long attracted attention of researchers in relation to both astrophysical phenomena [1][2][3] and laboratory experiments [4][5][6][7] . Currently, interest in this problem is associated with the study of type II and type III solar radio bursts [8][9][10][11][12] and zebra-like fine spectral structures of solar radiation 13,14 , as well as with the search for promising schemes for generating high-power sub-THz and THz radiation in mirror traps [15][16][17][18] . Since open magnetic systems allow to inject multigigawatt electron beams, the conversion of even a small fraction of their power into radiation power (1-5%) would open up the possibility of generating THz pulses at the record gigawatt level.…”