In July 1934 Nikola Tesla, a prominent Serbian-American inventor, made remarkable claims for invention a principally new weapon. Tesla’s statement was published in New York Times and in other editions. Tesla described the weapon as an apparatus sending concentrated particle beams through the air. The beams had been called “death rays” (or sometimes "peace rays") by the press. The inventor described the weapon as being able to be used against ground based infantry or for antiaircraft purposes. Tesla emphasized a tremendous energy of particle beams, thanks to which they could take out up to 10,000 enemy airplanes and an enormous number of soldiers from 250 miles away.

The information about possible appearance of new weapon could not help evoking great interest of the Council of Labour and Defenses and other leaders in the Soviet Republic. After discussing the question with experts it was decided to carry out researches and developments in this field in USSR. The task to investigate the possibility of making mysterious “death rays” was assigned to the Leningrad Electrophysical Institute. In 1935 the Institute received “numbered” title NII-9 and was turned over to the Aircraft Industry.

A new subject of investigation in the Institute became the development of powerful generators of electromagnetic energy in ultrahigh frequency (UHF) range. Some members of the staff considered such devices unpromising for antiaircraft and similar purposes. So academician A. Chernyshov, director of the Institute, future academicians Yu. Kobzarev, N. Papalexi, and other scientists decided to get their discharge from the Institute.

Subsequent works in the NII-9 showed that electromagnetic radiation in the UHF range could cause engine misfiring only in old wooden aeroplanes. New aircrafts with metal fuselages were practically insensitive to UHF rays. In 1937 ten engineers together with N. Smirnov, director of the NII-9, were arrested. They were imprisoned for two years. Then the results of their work were called for: powerful UHF generators found application in radar equipment, in UHF hardening, etc.

In 1938 the NII-9 together with other institutions developed the radar station with the distance of finding the aircrafts up to 100 km. The authorities forgot about the “death rays”, but only for some two decades: to the appearance of the devices of quantum electronics.