May 15, 2025 · Quadrupole Moment and Potential by Dr. Colton, Physics 441 (last updated: 15 May 2025)

When acquiring mass spectra with unit resolution for ions originating from a continuous source (that is, ions being presented to the mass spectrometer as a steady stream) the duty cycle of a quadrupole …

We shall see shortly that c0 is identified with the net charge Q of the system. Some writers will identify c1 as “the” dipole moment of the system, and c2 (or some simple multiple of it) as “the” quadrupole …

3 åˆri ˆrj ij = 1 i;j=1 since ˆr is a unit vector. The quadrupole moment is defined by (12)

This presentation approach is unique to any yet found in the literature, with its focus on practical implications of quadrupole theory, de-emphasizing the complex abstract equations typically util-ized …

quadrupole layout: Figure 2: Schematic of a quadrupole mass filter. A quadrupole mass spectrometer consists of an ionizer (bombardment by electrons from a hot filament), an ion accelerator, and a …

3.2 The field of an electric dipole 3.3 The torque on a dipole in an external E-field 3.4 The energy of a dipole in an external E-field 3.5 The quadrupole potential 3.6 The general multipole expansion