Patent ID: 9366650
Filing Date: 2016-06-14
CPC Classification: G01N,H01J

Claim Text:
1. A method for determining a mobility of ions, including the steps of: modulating an ion beam with an ion gate which is controlled by a modulation function for generating a modulated ion beam, wherein said modulation function is a pseudorandom sequence generated with a linear feedback shift register and wherein an autocorrelation of said modulation function is a two-valued function, guiding said modulated ion beam through a drifting region, measuring a signal of said modulated ion beam after said modulated ion beam has passed said drifting region, calculating a correlation of said modulation function and said signal in order to determine said mobility of said ions, wherein an interval of interest of possible ion drift times is chosen from said correlation and in that the method comprises a step of selecting said modulation function by selecting a tap set of said linear feedback shift register such that as many as possible false peaks in said correlation are located outside of said interval of interest.