Performance and future of the KATRIN experiment after 6 years of tritium operation

The Karlsruhe Tritium Neutrino experiment (KATRIN) searches for the effective electron neutrino mass with electrons from the β-decay of tritium with an unprecedented sensitivity of <0.3 eV/c2. The β-electrons are guided magnetically through the 70-m long setup, moving from the gaseous tritium source through a differential pumping section (DPS) and a cryogenic pumping section (CPS) to the high-resolution spectrometer. In the spectrometer, the kinetic energies of the decay electrons are analysed in an electrostatic high-pass filter (MAC-E-filter). Background considerations require a very good vacuum in the order of 10-11 mbar in the large spectrometer vessel (volume 1240 m3, surface: 1222 m2). A combination of NEG pumps and turbo-molecular pumps reliably provides the necessary pumping speed since more than 10 years. In addition, a very clean surface and low outgassing rates are mandatory.

After several years of engineering runs, the experiment started full tritium operation in March 2019, searching for the effective mass of electron-anti-neutrinos. These measurements will finally end in December 2025, followed by hardware upgrades and a new physics program. ... mehrThis talk reports on the performance of the components, after almost 20 years of R&D and 6 years of tritium operation with special emphasis on vacuum-related issues, followed by a description of future plans for the KATRIN setup.