AVS 53rd International Symposium
    Vacuum Technology Tuesday Sessions
       Session VT-TuA

Paper VT-TuA3
1450 m@super 3@ at 10@super -9@ Pa: One of the KATRIN Challenges

Tuesday, November 14, 2006, 2:40 pm, Room 2000

Session: Extreme High Vacuum and Vacuum Metrology
Presenter: Chr. Day, Forschungszentrum Karlsruhe, Germany
Authors: Chr. Day, Forschungszentrum Karlsruhe, Germany
R. Gumbsheimer, Forschungszentrum Karlsruhe, Germany
W. Herz, Forschungszentrum Karlsruhe, Germany
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The KATRIN project is a challenging experiment to measure the mass of the electron neutrino directly with a sensitivity of 0.2 eV. It is a next generation tritium beta-decay experiment scaling up the size and precision of previous experiments by an order of magnitude as well as the intensity of the tritium beta source. Ultrafine spectrometric analysis of the energy distribution of the decay electrons at their very endpoint of 18.57 keV is the key to derive the neutrino mass. This is provided by a high-resolution spectrometer of unique size (10 m in diameter, 22 m in length). To avoid any negative influence from residual gas, the spectrometer vessel is designed to UHV/XHV conditions (an ultimate total pressure of below 10@super -9@ Pa and a wall outgassing rate below 10@super -13@ Pam@super 3@/scm@super 2@). The paper shortly describes the experimental idea behind KATRIN. The emphasis will then be given to the pumping concept for how to achieve the target parameters and to the manufacturing of the spectrometer tank. Critical issues will also be discussed (surface treatment, welding, transportation). Finally, a description of the current status and an outlook on the overall KATRIN schedule completes the paper.