π root 2 iron-free magnetic electron spectrometer

The Radioactivity and Decay Schemes group at the Idaho National Engineering Laboratory has constructed and operated a π√2, iron-free, magnetic electron spectrometer. This instrument is of the ''Chalk River'' design with three pairs of circular coils to produce the magnetic field. The optic circle radius is 35 cm. The diameters of the coils and their axial separations were chosen to produce the desired magnetic field. This spectrometer is capable of measuring electron and positron spectra up to approximately 3.3 MeV with a resolution (i.e., relative FWHM) variable from 1 to 0.01 percent. A PDP-8/E computer is used to operate and monitor the spectrometer. It is programmed to automatically set the current in the coils, monitor the current and control the counting intervals. The spectrometer is housed in a building constructed of nonmagnetic materials and is situated to minimize the magnetic interference from vehicular movements. The spectrometer has been used to measure the continuous electron and positron spectra from several isotopes as well as several conversion electron spectra