July 25, 2007 to August 1, 2007
Karlsruhe University
Europe/Zurich timezone

Systematics and background suppression in the KATRIN experiment

Jul 27, 2007, 3:40 PM
Lehmann-Auditorium (Karlsruhe University)


Karlsruhe University

Wolfgang-Gaede-Str. 1 76131 Karlsruhe Germany
Parallel Talk Cosmology and Astrophysics Cosmology 3


Kathrin Valerius (Institut für Kernphysik, WWU Münster)


Despite the results of neutrino oscillation experiments providing compelling evidence for non-zero neutrino masses, the absolute mass scale still remains undetermined. This question, which has a strong impact on both particle physics and cosmology, can be addressed in several, complementary ways, either via astrophysical observations or by laboratory experiments. The direct neutrino mass determination relies on a precise measurement of the $\beta$ spectrum (tritium, $^{187}\textrm{Re}$) near its endpoint region. Recent experiments at Mainz and Troitsk using tritium $\beta$ decay have reached their sensitivity potential, yielding upper limits of about $\unit[2]{eV/c^2}$ for $m(\overline{\nu}_e)$. The {\bf KA}rlsruhe {\bf TRI}tium {\bf N}eutrino ex\-peri\-ment (KATRIN), designed to reach a sensitivity of $m(\overline{\nu}_e) = \unit[0.2]{eV/c^2}$ (90\% C.L.), will improve the signal rate by a factor of $> 100$ with respect to previous experiments while maintaining the same low background level at an enhanced energy resolution of 0.93~eV of the spectrometer which is scaled up by a factor of 10 in linear dimensions. This low background rate can only be achieved by active and passive reduction of the background components induced by the spectrometer itself and in the detector region. Furthermore, sources of systematic errors such as energy losses inside the tritium source or fluctuations of the energy scale of the spectrometer need to be carefully controlled and analyzed. An overview of KATRIN`s method to reduce the background rate and to determine the systematics as well as the sensitivity on the neutrino mass will be presented.

Primary authors

KATRIN-Collaboration Kathrin Valerius (Institut für Kernphysik, WWU Münster)

Presentation materials