DISINTEGRATION-RATE DETERMINATION BY 4π-COUNTING: PART IV. SELF-ABSORPTION CORRECTION: GENERAL METHOD AND APPLICATION TO Ni63 β-RADIATION

Abstract

A method of preparing thin uniform sources of radioactive materials for use in a 4π counter is described. The radioactive nuclides are formed into organic compounds and are subsequently distilled on to thin VYNS films. Electron microscope photographs of the deposits are shown. The material is uniformly deposited in crystals of about 1 μ in diameter. The distillation can be rendered quantitative. The amount of material on the film can be estimated either spectrophotometrically in situ or by appropriate chemical means. Using this method a self-absorption curve for Ni⁶³ (maximum beta energy 67 kev.) is obtained.