6th Symposium on Neutrinos and Dark Matter in Nuclear Physics 2018

The Electron Capture in 163Ho experiment – ECHo

3 Jul 2018, 12:00

30m

IBS HQ, Daejeon, Korea

Oral Plenary Session 8

Speaker

Prof. Loredana Gastaldo (Heidelberg University, Kirchhoff Institute for Physics)

Description

Direct determination of the electron neutrino $m({\nu }_{\mathrm{e}})$ and anti-neutrino mass $m({\overline{\nu }}_{\mathrm{e}})$ can be obtained by the analysis of electron capture and beta spectra respectively. In the last years experiments analyzing the ${}^3$H beta spectrum reached a limit on $m({\overline{\nu }}_{\mathrm{e}})$ of 2 eV. The upper limit on $m({\nu }_{\mathrm{e}})$ is still two orders of magnitudes higher, at 225 eV. The Electron Capture in ${}^{163}$Ho experiment, ECHo, is designed to investigate $m({\nu }_{\mathrm{e}})$ in the sub-eV region. In ECHo, high sensitivity on a finite $m({\nu }_{\mathrm{e}})$ will be reached by the analysis of the endpoint region in high statistics and high resolution calorimetrically measured ${}^{163}$Ho spectra. To perform this experiment, high purity ${}^{163}$Ho sources will be enclosed in a large number of low temperature metallic magnetic micro-calorimeters which are readout using the microwave multiplexing technique. This approach allows for a very good energy resolution, below $\mathrm{\Delta }{E}_{\mathrm{FWHM}}<5$ eV and for a fast time resolution well below 1 𝜇s. Thanks to the modular approach, the ECHo experiment is designed to be stepwise up-graded. The first on-going phase, ECHo-1k, is characterized by a ${}^{163}$Ho activity of about 1 kBq enclosed in about 100 pixels. The statistics of ${10}^{10}$ events in the ${}^{163}$Ho spectrum will allow for improving the limit on $m({\nu }_{\mathrm{e}})$ by more than one order of magnitude. In this talk, the present status of the ECHo-1k experiment will be discussed as well as the plans for the next phase, ECHo-100k.

Presentation materials

Slides

3._Gastaldo_Loredana.pdf