E parallel B canted detector neutral-particle spectrometer

Abstract

A multichannel, mass-discriminating, neutral-particle spectrometer using parallel E and B analyzer fields has been operational on the Doublet III tokamak. The device records 60 energy channels each of hydrogen and deuterium, simultaneously, during a shot with a dynamic range in energy of greater than 20. Its unique feature is a microchannel plate detector plane set at an angle to the exit face of the magnet. This angled detector plane linearizes the columns of each mass which simplifies the detector design, and permits the magnet gap to be very small. The narrow gap minimizes figure field effects on particle trajectories and simplifies power supply and cooling design. Details are given on the design, calibration, and instrumentation of the device, as well as on its operation and experimental results.