The Role of Static Charge in Ultra-Low Alpha Particle Emissivity Measurements

Electrically-insulating samples placed on the grounded sample tray in ionization detectors perturb the electric field within the detector. The resulting alpha particle emissivity of the samples is reduced depending on the magnitude and polarity of the surface voltage. Data are shown for samples with positive and negative surface charge, as well as methods to both measure and eliminate the effects of the surface charge.