Magnetic field effects in electrostatic analyzers used for heavy ion beam probe measurements

Abstract

Several recent experiments have heavy-ion-beam-probe diagnostics with analyzers that are located in regions outside of the vacuum system where the magnetic field strength is several hundred gauss or higher. The combination of high secondary particle velocity and high magnetic field inside the analyzer produces magnetic forces that are not negligible when compared to the electric force on these particles. Large errors in the measured plasma potential can result if the magnetic field is not properly taken into account. If the magnetic field is homogeneous, a completely analytic treatment of the analyzer is possible. The analyzer gain and the location and shape of the secondary beam image on the detector plates can be determined without having to calculate the entire trajectory through the analyzer. If the field is not homogeneous, a numerical calculation of the trajectory is necessary.<>