In:
Review of Scientific Instruments, AIP Publishing, Vol. 80, No. 10 ( 2009-10-01)
Abstract:
The energy-sensitive detection of heavy ions with calorimetric low temperature detectors was investigated in the energy range of E=0.1–1 MeV/amu, commonly used for accelerator mass spectrometry (AMS). The detectors used consist of sapphire absorbers and superconducting aluminum transition edge thermometers operated at T∼1.5 K. They were irradiated with various ion beams (C13,A197u,U238) provided by the VERA tandem accelerator in Vienna, Austria. The relative energy resolution obtained was ΔE/E=(5–9)×10−3, even for the heaviest ions such as U238. In addition, no evidence for a pulse height defect was observed. This performance allowed for the first time to apply a calorimetric low temperature detector in an AMS experiment. The aim was to precisely determine the isotope ratio of U236/U238 for several samples of natural uranium, U236 being known as a sensitive monitor for neutron fluxes. Replacing a conventionally used detection system at VERA by the calorimetric detector enabled to substantially reduce background from neighboring isotopes and to increase the detection efficiency. Due to the high sensitivity achieved, a value of U236/U238=6.1×10−12 could be obtained, representing the smallest U236/U238 ratio measured at the time. In addition, we contributed to establishing an improved material standard of U236/U238, which can be used as a reference for future AMS measurements.
Type of Medium:
Online Resource
ISSN:
0034-6748
,
1089-7623
Language:
English
Publisher:
AIP Publishing
Publication Date:
2009
detail.hit.zdb_id:
209865-9
detail.hit.zdb_id:
1472905-2
SSG:
11
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