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Physics, Instrumentation and Detectors, physics.ins-det
MPINP:
Speichertechnik - Abteilung Blaum
Abstract:
The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the
effective electron (anti)neutrino mass with a sensitivity of $0.2\textrm{
eV/c}^2$ (90$\%$ C.L.) by precisely measuring the endpoint region of the
tritium $\beta$-decay spectrum. It uses a tandem of electrostatic spectrometers
working as MAC-E (magnetic adiabatic collimation combined with an
electrostatic) filters. In the space between the pre-spectrometer and the main
spectrometer, an unavoidable Penning trap is created when the superconducting
magnet between the two spectrometers, biased at their respective nominal
potentials, is energized. The electrons accumulated in this trap can lead to
discharges, which create additional background electrons and endanger the
spectrometer and detector section downstream. To counteract this problem,
"electron catchers" were installed in the beamline inside the magnet bore
between the two spectrometers. These catchers can be moved across the
magnetic-flux tube and intercept on a sub-ms time scale the stored electrons
along their magnetron motion paths. In this paper, we report on the design and
the successful commissioning of the electron catchers and present results on
their efficiency in reducing the experimental background.
