Development of a Miniaturized Hadamard Transform Time-of-Flight Mass Spectrometer

Abstract : This report details advances in theory and technology for the precise deflection of high kinetic energy ion beams using Bradbury-Nielsen gates (BNGs) and their application to high duty cycle miniaturized mass spectrometry. We have developed methods to fabricate BNGs using template assisted manual weaving and silicon-on-insulator microfabrication. These devices have been characterized using ion beam imaging techniques, and the results compared to mathematical models of the deflection process developed for this purpose. A new vacuum-compatible electronic system has been constructed to allow the deflection of ions using BNGs following an arbitrary digital sequence that minimizes the impact of impedance mismatching within the circuit and improves the precision of deflection. The aforementioned advances have been integrated to develop a new form of time-of-flight mass spectrometry that allows for 100% duty cycle detection of a continuous ion beam. Experiments detailing 100% duty cycle operation are described. The statistical advantages to this form of detection over other forms of mass spectrometry in a shot noise dominant environment are presented.