Large Bradbury–Nielsen Gate Optimized for Electrospray Time of Flight Spectroscopy

A large, 4 in.2, low-cost Bradbury–Nielsen gate (BNG) was developed and optimized to reduce diagnostic noise and high-energy ion impingement damage to electrospray thrusters during time-of-flight spectroscopy (TOFS). This new BNG increased diagnostic ion transparency by 633%, significantly increased the signal-to-noise ratio in the raw data collection, and reduced thruster damage due to high-energy ionic bombardment during ion diversion. By deflecting the thruster’s ionic plume, as opposed to the conventional method of reflection, the BNG can be operated at 50–75% lower cyclic voltages, thus reducing high-frequency noise induced by the required high-voltage, high-frequency gate operation. The BNG reduces high-energy ion impingement on the thruster’s extraction surface by up to 98.9%. This significant reduction in return current allows for unaltered measurements of performance and enables repeated diagnostic use without deleterious effects during long test campaigns.