Wide-band system for radio-frequency pumping a double electron-nuclear resonance spectrometer

A RF pumping system for a double electron-nuclear resonance spectrometer with a wideband matching of a RF coil with a source is described. The system comprises a low-power generator, a distributed-amplification power amplifier, a coil and an absorbing load. The proposed version of the system makes it possible to obtain, at a pumping generator output power of 85 W on a load of 50 Ohm, the 10 Oe magnetic field amplitude over the frequency range from 0.5 to 70 MHz. It is shown that simple protection measures against spurious radiation of the system allow its usage together with the highly sensitive superheterodyne EPR radiospectrometer with an intermediate frequency of 30 MHz