Acceptance and transmittance of a quadrupole mass filter with amplitude modulation of RF voltage with allowance for an edge field

A method for calculating the acceptance of a quadrupole mass filter with amplitude modulation of rf voltage is developed. The key factor in determining the transformation of the phase ellipse by edge fields is taking into account the phase shift of the rf field during motion of ions in the input edge field. The variation of the combined acceptance depending on the axial energy of ions (or the transit time of ions through the edge field) is in conformity with the rated transmittance, which is an indirect indication of the correctness of the proposed approach.