ABSTRACT
The physics of the interactions of moving charged particles with electric and magnetic fields is reviewed and then the operating principles of various instruments that manipulate the charged particles or charged particle beams are discussed. The instruments included start with the basic parallel plate electrostatic analyser (ESA) and its developments into the cylindrical deflection analyser and the top hat analyser. Electrostatic lenses and ‘prisms’ (the quadrupole beam deflector) are then considered. An account of magnetic field–based instruments follows and includes magnetic lenses (solenoid and quadrupole), velocity selectors and ion drift meters. All these instruments’ designs are illustrated by case studies of exemplars from current or past spacecraft missions.
The operating principles and designs of mass spectrometers are reported on in detail (the gas chromatograph, often used together with the mass spectrometer, is covered in Chapter 7). The designs discussed include the magnetic sector mass spectrometer and the electric field–based quadrupole, dynamic ion and electrostatic mass spectrometers. Time-of-flight (ToF) mass spectrometers are also discussed along with possible future developments. Examples of all these designs and their applications within spacecraft-borne and other instruments are then discussed in detail.
