Proton detection

The neutron lifetime will be determined at tSPECT by measuring the decay curve online. This is achieved be measuring the decay products of the beta decay, protons and electrons, with a silicon drift detector (SDD). Such an in-situ measurement of the decay curve is independent of the knowledge of the absolute number of stored UCN or the knowledge of fluctuations of the beam intensity or capture efficiency.

The detection system used at tSPECT is based on the proton detection system of the aSPECT experiments. There it was successfully used to detect protons from neutron decay in order to determine the beta-neutrino angular correlation in neutron decay. In recent years it has been modified to also detect electrons. It will now be used with only minor alterations for the decay particle detection at tSPECT.

New SDD detector in its test chamber:

SDD detector during calibration tests 

Calibration tests of the SDD detector and its electronics:

Detector tests in the test chamber