0000000000291359
AUTHOR
H. J. Meier
Noise analysis for calorimetric low-temperature detectors for heavy ions
The energy resolution of calorimetric low-temperature detectors for heavy ions has been analyzed. It is shown that the contribution of base line noise is small. The energy resolution is determined by intrinsic fluctuations of the detector signal. An incomplete energy thermalization during the stopping process of the heavy ion, the dependence of signal shape on impact position and fluctuations of the Al-TES thermometer response are considered as main sources of detector line broadening. Test measurements with 5 MeV α-particles are presented.
Low-temperature X-ray detectors for precise Lamb shift measurements on hydrogen-like heavy ions
The precise determination of the Lamb shift in heavy hydrogen-like ions provides a sensitive test of quantum electrodynamics in very strong Coulomb"elds, not accessible otherwise. For the investigation of the Lyman-a transitions in 208Pb81‘ or 238U91‘ with su$cient accuracy a high resolving calorimetric detector for hard X-rays (E)100 keV) is presently developed. The detector modules consist of arrays of silicon thermistors and of X-ray absorbers made of high Z material to optimize the absorption e$ciency. The detectors are housed in a specially designed 3He/4He dilution refrigerator with a side arm which "ts to the geometry of the internal target of the storage ring ESR at GSI Darmstadt. T…