Emission current regulator for ion cyclotron resonance spectrometers using an optical coupler

An electron emission current regulator for an ion cyclotron resonance spectrometer which operates well in the pulsed grid modulation mode for frequencies above 30 Hz was constructed. It regulates the filament current by comparing the feed-back signal of the electron emission current with a reference voltage. The feed-back signal is transmitted through an optical coupler from the emission current detector to the filament circuit since the common voltages of these circuits are different. It regulates the emission current in the range from 10-6 to 10-9 A maintaining a stability of 0.2% h-1. (Auth.)