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funding:start [2016/10/16 21:17] 127.0.0.1 external edit |
funding:start [2018/10/10 13:03] Maurits W. Haverkort |
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| ===== Funding ===== | ===== Funding ===== | ||
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| + | ==== DFG Research Unit FOR 2202 ==== | ||
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| + | Neutrino Mass Determination by Electron Capture in Holmium-163 – ECHo | ||
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| + | For many years, the kinematic determination of the electron anti-neutrino mass has been associated to the measurement of the tritium beta spectrum. This approach led to the most stringent upper limit on the electron anti-neutrino mass of about 2 eV/c<sup>2</sup> at 95% C.L.. At the same time the most stringent upper limit on the electron neutrino mass is presently 225 eV/c<sup>2</sup> at 95% C.L. obtained by the analysis of the <sup>163</sup>Ho X-ray spectrum. The Electron Capture <sup>163</sup>Ho experiment, ECHo, is designed to investigate the electron neutrino mass in the sub-eV/c<sup>2</sup> range by means of the analysis of the calorimetrically measured energy spectrum following the electron capture process of 163Ho. In the ECHo experiment, arrays of low temperature metallic magnetic calorimeters with high energy resolution and fast response time, having the high purity 163Ho source embedded in the absorber, will be used to calorimetrically measure the EC spectrum in a low background environment. Thanks to the results obtained by the working groups of the DFG Research Unit ECHo within the first funding period, the possibility to improve the limit on the electron neutrino mass at the level of the limit on the anti- neutrino mass seems today in reach. Not only methods for the production of large activity of high purity 163Ho sources, the development of high energy resolution large MMC arrays with multiplex readout and the identification and suppression of background sources which allow for the precise measurement of the <sup>163</sup>Ho spectrum, but also a more precise determination of the expected spectral shape have been obtained during the last three years. Moreover, the independent determination of the QEC-value by Penning-Trap Mass Spectrometry and by the analysis of the calorimetrically measured spectrum showed consistent results pointing out the reliability of the 163Ho spectrum measurement technique. | ||
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| + | For more information please visit the site of [[https://www.kip.uni-heidelberg.de/for2202/|FOR 2202: ECHo]] | ||
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| ==== DFG Research Unit FOR 1346 ==== | ==== DFG Research Unit FOR 1346 ==== | ||