Design Curves for 180° Magnetic Spectrometers

Abstract

The image shapes resulting from 180° focusing of charged particles in a homogeneous magnetic field have been computed. General curves are presented in terms of three variables for variable ρ‐spectrometers (as in the case of photographic detection) and in terms of four variables for constant ρ‐spectrometers (as in the case of detection with a fixed counter). The variables are source and exit‐slit height, source width, angular selection, and exit‐slit width. The advantages of using sources and exit‐slits with a large dimension parallel to the magnetic field (i.e., height) are noted.