Laser methods for generating megavolt terahertz pulses

Abstract

Optimization of the CO 2 laser ran into difficulties because of the lack of understanding of the mechanism responsible for the production of inversion between vibrational levels in a gas discharge. The situation became clear with the emergence of a paper by N N Sobolev and V V Sokovikov [21] and Ref. [22] that followed. The authors compared data on the average electron energy in the discharge with the energy dependence of the excitation cross section for the corresponding molecular vibrational levels and saw that the electron impact mechanism is highly efficient. In this case, the inversion between vibrational levels is produced due to collisions with atoms and molecules. When these papers appeared, a start was made on a targeted theoretical description of the CO 2 laser and a new impetus was given to experiments aimed at its improvement. Notably, the USSR's first CO 2 gas-dynamic laser was put into operation in the framework of this work [23]. 8. Conclusions Summarizing the foregoing material, one may draw a conclusion on what underlay the success of Soviet science in the development of lasers. In the USSR there existed a large community of highly qualified scientists, which was permanently fed by scientific personnel from institutes of higher education (the Moscow Institute of Physics and Technology (MIPT), M V Lomonosov Moscow State University, the Moscow Engineering Physics Institute, etc.). From MIPT alone (MIPT was founded for preparing researchers in physics) several hundred graduates came to the LPI during the postwar years. The leaders of the laser program, N G Basov and A M Prokhorov, could rely on the scientific schools nourished by S I Vavilov, G S Landsberg, and L I Mandel'shtam at LPI. A system of financing the research had functioned in the USSR. The government responded to the needs of science and stimulated scientific progress. New facilities were commissioned to promote laser research: buildings on the LPI territory, branches of the LPI in Troitsk with accommodation for scientists, the Institute of Spectroscopy, the Polyus Scientific Production Association, and other laser research institutes. USSR industries were capable of providing the requisite components and instruments for research; in the USSR there were works for creating big research facilities and technologies for producing unique materials. Notwithstanding the known shortcomings of the govern-ance of that time, a strategically weighed program of scientific and technological development existed in the country. Laser research was a part of this program.