Novel method for the production of finely spaced Bradbury–Nielson gates

Bradbury–Nielson gates for the modulation of beams of charged particles, particularly ion beams in mass spectrometry, have been produced with an adjustable wire spacing down to 0.075 mm. The gates are robust, they can be fabricated in less than 3 h, and the method of production is reproducible. In time-of-flight mass spectrometers, fine wire spacing leads to improvements in mass resolution and modulation rates. Gates that were produced using this new method have been installed in a Hadamard transform time-of-flight mass spectrometer in order to demonstrate their utility.