Investigation of a Quadrupole Mass Filter Employing a Novel Digital Waveform and Discontinuous Ion Introduction

Abstract

Theoretical investigation of a quadrupole mass filter using an ion conditioning system to synchronise ion entry with the optimal phase of the applied Radio Frequency (RF) signal in order to improve the resolution of the instrument. The RF signal that is proposed to be used is the N6 EC signal described by E. Sheretov. The goal of the project was to simulate the performance of a quadrupole mass filter driven with such a signal, and compare this with conventional RF signals. The theory behind the EC signals was investigated, and it is shown that the EC signal increases the optimal input phase region significantly compared to conventional RF signals. The transmission of a bunch of ions was investigated for a quadrupole mass filter driven by the N6 EC signal, and the impacts of altering temperature, operating line, and initial RF phase were studied. The N6 EC is shown to improve the transmission resolution and peak shape compared to a sinusoidal RF. The origins of the improvements is discussed. The impact of quadrupole rod parameters on the transmission performance was investigated, and a maximum theoretical attainable resolution was calculated to be over 75,000, where resolution is defines as mass divided by full width half maximum of the peak.

Date of Award	1 Aug 2020
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Robert Appleby (Supervisor) & Hywel Owen (Supervisor)