Outgassing measurements after 350 C bake-out of the KATRIN spectrometer

The Karlsruhe Tritium neutrino experiment (KATRIN) aims to measure the electron neutrino mass from the β-decay of tritium with an unprecedented sensitivity of 0.2 eV/c2. The kinetic energy of the decay electrons will be measured in an electrostatic spectrometer. Background considerations require a very good vacuum of 10-11 mbar or better in the large spectrometer vessel (volume 1240 m3, surface: 690 m2). A combination of NEG pumps and turbo-molecular pumps will provide the necessary pumping speed. In addition a very clean surface and low outgassing rates are mandatory. This talk reports on the commissioning and final outgassing measurements before and after bake-out at 350 C