Wuppertal 2015 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

T: Fachverband Teilchenphysik

T 94: Niederenergie Neutrinophysik VI

T 94.3: Talk

Thursday, March 12, 2015, 17:15–17:30, I.13.71 (HS 28)

Optimization of metallic magnetic calorimeters for high resolution measurement of the ¹⁶³Ho electron capture spectrum — •Sebastian Hähnle for the ECHo collaboration — Kirchhoff-Institute for Physics, Heidelberg University, Germany

The absolute scale of the neutrino mass eigenstates is one of the puzzles in modern particle physics. One method to investigate the value of the electron neutrino mass is to analyse the high energy region of the ¹⁶³Ho electron capture spectrum. In the ECHo experiment low temperature metallic magnetic calorimeters (MMCs) are used for the calorimetric measurements of the EC spectrum of 163Ho. To ensure 100% quantum efficiency, the ¹⁶³Ho ions are implanted into the gold absorber. Experiments carried out with a first detector prototype have demonstrated that MMC-based detectors fulfill the requirements in terms of energy resolution, rise-time and energy calibration. We discuss methods to further optimize the performance of MMCs with implanted ¹⁶³Ho. Our aim is to achieve an energy resolution Δ E_FWHM < 5 eV and a signal rise-time τ < 100 ns. An important aspect of this optimization is to define the maximum activity per pixel. This will result from a compromise between allowed unresolved pile-up fraction, additional heat capacity in the absorber due to Ho ions in the absorber material and minimization of the pixel number. We discuss experimental approaches for the determination of the optimal activity per pixel.