Application of low temperature calorimeters for the detection of energetic heavy ions

The energy sensitive detection of energetic heavy ions with calorimetric low temperature detectors is investigated. The temperature readout was done with an aluminum transition edge thermometer operated at T ≈ 1.5 K. For ²⁰Ne-ions with an energy of E = 100 MeV/u from the SIS accelerator at GSI Darmstadt the best energy resolution obtained was {ΔE}/{E} = 1.9 × 10 ^-3. This value corresponds to the energy spread of the ion beam of the SIS. In a first application of such detectors the excitation of the giant resonance in lead nuclei via the reaction ^natPb( ²⁰Ne, ²⁰Ne') ^natPb ^∗ was investigated by separating inelastically from elastically scattered ²⁰Ne-ions in the energy spectrum. At a scattering angle Θ_Lab = 3° the excitation energy and the strength of the giant resonance were found to be in good agreement with theoretical predictions. In a first test with an extracted cooled ²³⁸U-beam with an energy of E = 360 MeV/u from the storage ring ESR with an intrinsic beam energy spread of {ΔE}/{E} ≤ 2 × 10 ^-4 an energy resolution of ΔE = 97 MeV ( {ΔE}/{E} = 1.1 × 10 ^-3) was measured. The baseline noise was ΔE = 17 MeV. Further improvement of the energy resolution seems possible.