13 research outputs found
Precision high voltage divider for the KATRIN experiment
The Karlsruhe Tritium Neutrino Experiment (KATRIN) aims to determine the
absolute mass of the electron antineutrino from a precise measurement of the
tritium beta-spectrum near its endpoint at 18.6 keV with a sensitivity of 0.2
eV. KATRIN uses an electrostatic retardation spectrometer of MAC-E filter type
for which it is crucial to monitor high voltages of up to 35 kV with a
precision and long-term stability at the ppm level. Since devices capable of
this precision are not commercially available, a new high voltage divider for
direct voltages of up to 35 kV has been designed, following the new concept of
the standard divider for direct voltages of up to 100 kV developed at the
Physikalisch-Technische Bundesanstalt (PTB). The electrical and mechanical
design of the divider, the screening procedure for the selection of the
precision resistors, and the results of the investigation and calibration at
PTB are reported here. During the latter, uncertainties at the low ppm level
have been deduced for the new divider, thus qualifying it for the precision
measurements of the KATRIN experiment.Comment: 22 pages, 12 figure
The KATRIN Experiment
The KArlsruhe TRitium Neutrino mass experiment, KATRIN, aims to search for
the mass of the electron neutrino with a sensitivity of 0.2 eV/c^2 (90% C.L.)
and a detection limit of 0.35 eV/c^2 (5 sigma). Both a positive or a negative
result will have far reaching implications for cosmology and the standard model
of particle physics and will give new input for astroparticle physics and
cosmology. The major components of KATRIN are being set up at the Karlsruhe
Institut of Technology in Karlsruhe, Germany, and test measurements of the
individual components have started. Data taking with tritium is scheduled to
start in 2012.Comment: 3 pages, 1 figure, proceedings of the TAUP 2009 International
Conference on Topics in Astroparticle and Underground Physics, to be
published in Journal of Physics, Conference Serie
Final Results from phase II of the Mainz Neutrino Mass Search in Tritium Decay
The paper reports on the improved Mainz experiment on tritum
spectroscopy which yields a 10 times' higher signal to background ratio than
before. The main experimental effects and systematic uncertainties have been
investigated in side experiments and possible error sources have been
eliminated. Extensive data taking took place in the years 1997 to 2001. A
residual analysis of the data sets yields for the square of the electron
antineutrino mass the final result of eV/c. We derive an upper limit of
eV/c at 95% confidence level for the mass itself.Comment: 22 pages, 22 figures submitted to EPJ
The KATRIN Pre-Spectrometer at reduced Filter Energy
The KArlsruhe TRItium Neutrino experiment, KATRIN, will determine the mass of
the electron neutrino with a sensitivity of 0.2 eV (90% C.L.) via a measurement
of the beta-spectrum of gaseous tritium near its endpoint of E_0 =18.57 keV. An
ultra-low background of about b = 10 mHz is among the requirements to reach
this sensitivity. In the KATRIN main beam-line two spectrometers of MAC-E
filter type are used in a tandem configuration. This setup, however, produces a
Penning trap which could lead to increased background. We have performed test
measurements showing that the filter energy of the pre-spectrometer can be
reduced by several keV in order to diminish this trap. These measurements were
analyzed with the help of a complex computer simulation, modeling multiple
electron reflections both from the detector and the photoelectric electron
source used in our test setup.Comment: 22 pages, 12 figure
Effect of a sweeping conductive wire on electrons stored in the Penning trap between the KATRIN spectrometers
The KATRIN experiment is going to search for the mass of the electron
antineutrino down to 0.2 eV/c^2. In order to reach this sensitivity the
background rate has to be understood and minimised to 0.01 counts per second.
One of the background sources is the unavoidable Penning trap for electrons due
to the combination of the electric and magnetic fields between the pre- and the
main spectrometer at KATRIN. In this article we will show that by sweeping a
conducting wire periodically through such a particle trap stored particles can
be removed, an ongoing discharge in the trap can be stopped, and the count rate
measured with a detector looking at the trap is reduced.Comment: Final version published in EPJ A, 14 pages, 19 figures (21 files