title: A low-noise current-sensitive amplifier-discriminator system for beta particle counting.
abstract: NPL has developed a low-noise current amplifier/discriminator system for radionuclides that emit low-energy electrons and X-rays. The new beta amplifier is based on the low-noise Amptek A-250 operational amplifier. The design has been configured for optimum signal to noise ratio. The new amplifier is described and results obtained using primarily electron-capture decaying radionuclides are presented. The new amplifier gives rise to higher particle detection efficiency than the previously used Atomic Energy of Canada Limited-designed amplifier. This is shown by measurements of (54)Mn and (65)Zn. The counting plateaux are significantly longer and have reduced gradients.
authors.affiliation: National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK. john.sephton@npl.co.uk
authors.forename: J P
authors.initials: JP
authors.lastname: Sephton
authors.forename: L C
authors.initials: LC
authors.lastname: Johansson
authors.forename: J M
authors.initials: JM
authors.lastname: Williams