Time of flight mass spectrometry with continuously operating ion source

Abstract

Developments in Continuous Time of Flight (CTOF) mass spectrometry which uses a continuously operating ion source and a special modulation demodulation technique are presented. The expected advantages are higher sensitivity and minor space charge limitations. The present article discusses the solution of the problems of beam modulation in conjunction with the appearance of higher harmonic ghost peaks in the Time Of Flight spectrum, as well as the construction of the modulator device in order to allow modulation frequencies high enough for satisfactory resolution. The objective of the experimental set-up is to demonstrate the operation of this novel measuring principle and the effectiveness of the developments. The CTOF method is far less limited by physics than Pulsed Time of Flight (PTOF) techniques. By investing the same amount of effort to both methods, CTOF will likely outperform PTOF in most parameters.