Calorimetric low temperature detectors for mass identification of heavy ions

Abstract

The energy sensitive detection of heavy ions with calorimetric low temperature detectors (CLTDs) is investigated for the energy range E=0.1–1 MeV/u, commonly used for accelerator mass spectrometry (AMS). Such measurements complement earlier investigations [1, 2] at higher energies (E=5–300 MeV/u) where an energy resolution of ΔE/E=1–2×10−3 was obtained for various ion species. The detectors used consist of sapphire absorbers and superconducting transition edge thermometers operated at T≈1.5 K. They were irradiated with various heavy ion beams (13C, 197Au, 238U) provided by the VERA tandem accelerator in Vienna, Austria. An energy resolution of ΔE/E=5–6×10−3 has been obtained even for heaviest ions like 197Au and 238U at E=0.1–0.3 MeV/u, thereby exceeding the resolution of conventional semiconductor detectors in this energy range by at least one order of magnitude. In addition, no evidence for pulse height defects has been observed. With the achieved performance, the present CLTDs bear a large potential fo...