Mode competition in relativistic carsinotron

1. In this paper we give the results of an experimental study of a relativistic carsinotron ^[1] at the wavelength of 3,2 sm under different operating conditions depending on an external magnetic field. The high-frequency output power of about 400 MW and a performance factor of about 15% have been achieved in our previous experiment ^[1]. Now the high-frequency power output is about 1 GW and the experimentally measured performance factor strives for a maximal theoretically predicted value (about 30%)^[2].