A low-noise current-sensitive amplifier-discriminator system for beta particle counting.
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.
Sephton
J P
JP
National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK. john.sephton@npl.co.uk
Johansson
L C
LC
Williams
J M
JM