Radiation of relativistic electrons in a variable undulator

A study is made of the polarization, spectral, and angular characteristics of the radiation of an electron in an arbitrary system of constant undulators with different strengths, distributions, periods, and number of periods of the magnetic field. It is shown that such a system enables one to obtain any form of the radiation spectrum in a wide range of wavelengths.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 48–51, June, 1977.