Continuously displayed emittance measurements

Abstract

A device is described to display continuously on a CRT the emittance of an ion beam. The system uses electrostatic deflectors and small apertures to scan the beam’s phase−space position and momentum coordinates. Measurements are reported of the emittance and brightness of the following beams produced by five different ion sources: H⁻, D⁻, He⁺, He⁻, C⁻, D₂⁻, O⁻, NH₂⁻, A⁺, and Cu⁻. Also investigated was the emittance of an H⁻ beam from a duoplasmatron direct−extraction source as a function of the radial displacement of the zwischen electrode, and the phase−space particle density distribution of an H⁻ beam was measured.