The spherical condenser as a high transmission particle spectrometer: I. Point source

Abstract

The inverse square electric field between two concentric charged spheres provides a focussing of charged particles which leave a point source on the inner sphere. An analysis of the transmission, resolution, and line profile shape which may be obtained with a spectrometer utilizing this focussing has been carried out analytically and graphically. It is found that the fractional transmission T is related to the resolution δ 1 2 (the fractional energy spread at half the maximum transmission) according to T = δ 1 2 . Transmi ssions as high as 25% are obtainable at 6% energy resolution with such a device.