Design of Temperature Stability for the Filament Current Controller in Spaceborne Time-of-Flight Mass Spectrometry

The regulation range and ripple of the filament current in a time-of-flight mass spectrometer directly impact the electron emission capability and stability, which are crucial performance indicators for determining ionization efficiency. This paper systematically investigates the temperature stability of the filament drive circuit in a mass spectrometer and designs a constant current drive circuit based on the RSS0508HRH chip. Through simulation analysis, methods for optimizing circuit stability are proposed and validated through experiments. The research results demonstrate that the constant current drive circuit designed with the RSS0508HRH chip achieves closed-loop feedback regulation of the filament emission current. The experiment conducted over a wide temperature range of −40°C to 75°C, the current remained stable, with an error margin controlled within 3%. The experimental data further confirm that this constant current drive circuit exhibits excellent temperature adaptability and stability, meeting the application requirements of mass spectrometers across varying temperature environments.