High-Speed Mass Spectrometer for Characterizing Multispecies Flash Desorbed Plasmas in Pulsed Power Applications*

Sandia National Laboratories operates the world’s largest pulsed power facility, the Z-machine, used for research in fusion, energy, and national security. However, it is experiencing a power flow problem that could be partially attributed to gas desorption when a pulse runs through the inner magnetically insulated transmission lines (MITL). Due to the high currents the Z-machine creates, the MITL electrode heats up, causing flash desorption and forming a plasma which causes current loss This project will help develop an ultra-fast mass spectrometer, allowing direct measurements of the gasses from the electrodes heated to 4000°C in 50 nanoseconds. A mass spectrometer with this capability would allow more accurate predictive modeling of current loss for Next Generation Pulsed Power Drivers. The design for this spectrometer is based on an existing plasma diagnostic, the Energy and Velocity Analyzer for Distributions of Electric Rockets (EVADER) probe, which combines an electrostatic analyzer and Wien filter, yielding the ion-energy distribution function of species and their charge state. Recent work has aimed to increase measurement speed while maintaining low current resolution. Evaluation of the improvements to the diagnostic will be performed on a well-characterized ion source.