AMS for M > 36 with a gas-filled magnetic spectrograph
Abstract
Small concentrations of long-lived radioisotopes such as 59Ni are not necessarily easy to determine by AMS because of the background of stable isobars, in this case 59Co. The gas-filled Q3D magnetic spectrograph has been successfully used for isobaric separation. Additional suppression of non-isobaric background is accomplished by means of a Wien filter directly after the tandem and a highly sensitive time-of-flight measurement just before the spectrograph. Until now we have used these techniques for the radioisotopes 41Ca, 59Ni, 90Sr and 107Pd. The limits in sensitivity are at present between ~ 3 × 10 -15 for 41Ca/Ca and ~ 1 × 10 -8 for 107Pd/ 106Pd. Measurements have been performed on environmental, extraterrestrial and nuclear waste samples. Because of the insufficient sensitivity for measurements of very low concentrations with the existing Q3D, a dedicated gas-filled magnet with a deflection angle of 135° is now under construction.
- Publication:
-
Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- June 1994
- DOI:
- 10.1016/0168-583X(94)95995-1
- Bibcode:
- 1994NIMPB..92..146K