Multi-frequency electron spin resonance apparatus using a high-power light source compact gyrotron
Abstract
We constructed a new multifrequency electron spin resonance (ESR) system by combining a compact-type gyrotron named FU CW CIA and a force-detection ESR measurement system with a variable temperature cryostat which can be used in the temperature range 5−300 K. Multi-frequency ESR signals of 1,1-diphenyl-2-picrylhydrazyl (DPPH) were successfully detected at 300 K. The sensitivity was obtained to be in the order of 1012 spins/G from the ESR measurement of Cu(C4H4N2)(NO3)2. These results indicate that the combination of a high-power wave-source gyrotron with multi-frequency oscillation and a force-detection system is well-matched to enable multi-frequency ESR measurements.