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 $m(\bar{\nu}_{\mathrm{e}})$ 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 $m(\bar{\nu}_{\mathrm{e}})$ 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 $\Delta E_{\mathrm{FWHM}} \, < \, 5$ 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.
| Co-Authors (Collaboration) | ECHo Collaboration |
|---|
Primary author
Prof.
Loredana Gastaldo
(Heidelberg University, Kirchhoff Institute for Physics)
