Protection of ion source electronics against dynamic conditions in ion source at elevated potentials in mass spectrometers

Failure in floating electronics (components) at elevated potentials of ion sources (like thermal ionization source, electron impact ionization source) in magnetic sector mass spectrometers, may occur due to random heavy discharges within the ion source region. Discharge is generally caused by the dynamic phenomenon like pressure fluctuations in the ion source, ion formation, source magnet movement (changes in the magnetic field) leading to sudden rise in emission current etc. Different protection topologies like short circuit protection, overvoltage protection, introduction of transient voltage suppressors (transorbs), and source resistance were employed to minimize the damage of electrode power supplies under normal conditions. Additionally, resistive ballast was added to avoid damage of the electronics due to discharges under floating conditions at high voltage. Implementation of the above mentioned protection methods ensured fault free performance of ion source electronic units over a longer period as compared to that without the protections.