Speaker
Dr
Stanislav Sinitsky
(Budker Institute of Nuclear Physics)
Description
Sub-terahertz emission from a plasma column at exciting strong Langmuir oscillation by a high current relativistic electron beam (REB) was experimentally studied at the GOL-3 facility (BINP)1. The typical parameters of the beam used in the experiments, were the following: 0.5÷0.7 MeV/20 kA/10 mcs. In recent experiments the beam current density was about 1÷2 kA/cm$^2$ in a plasma column with the density $\sim$2÷4·10$^{14}$ cm$^{-3}$ that allowed us to get sub THz-emission in the frequency range 100÷400 GHz.
To extend our experiments to the range of 1 THz we have to inject the beam into the plasma column of higher density 1÷2·10$^{15}$ cm$^{-3}$. For achieving the effective excitation of the plasma waves at this density, the substantial increase of the beam brightness is required. To solve this problem we have performed 2-D self-consistent simulations of the beam formation at various geometries of a magnetically insulated ribbon diode by the usage of numerical code POISSON-2. In addition, in the computer simulations we also considered the transformation of the generated ribbon beam to a circular one and its compression to the radius $\sim$2 cm in the magnetic field $\sim$4 T in which the plasma column is placed.
The quality of 2-D self-consistent simulations was tested by the data comparison with the results of measurements of the beam current density and the angular spread of the beam electrons at the previous experiments. Good agreement of the theoretical data with the experimental results allowed us to use the computer simulations for designing a novel diode configuration for the high brightness beam generation. The new diode configuration is described and discussed in the paper.
1. M.K.A. Thumm, A.V. Arzhannikov, V.T. Astrelin et al. Generation of High-Power Sub-THz Waves in Magnetized Turbulent Electron Beam Plasmas. J. of Infrared, Millimeter and Terahertz Waves. Vol. 35, Iss. 1, 2014, pp. 81-90, DOI 10.1007/s10762-013-9969-3
Primary author
Dr
Stanislav Sinitsky
(Budker Institute of Nuclear Physics)
Co-authors
Prof.
Andrey Arzhannikov
(Novosibirsk State University)
Maksim Makarov
(Budker Institute of Nuclear Physics)
Mr
Vasilii Stepanov
(Budker Institute of Nuclear Physics)
Dr
Vitaly Astrelin
(Budker Institute of Nuclear Physics)
