Sensors (Aug 2020)

Quantitative Long-Term Monitoring of the Circulating Gases in the KATRIN Experiment Using Raman Spectroscopy

  • Max Aker,
  • Konrad Altenmüller,
  • Armen Beglarian,
  • Jan Behrens,
  • Anatoly Berlev,
  • Uwe Besserer,
  • Benedikt Bieringer,
  • Klaus Blaum,
  • Fabian Block,
  • Beate Bornschein,
  • Lutz Bornschein,
  • Matthias Böttcher,
  • Tim Brunst,
  • Thomas C. Caldwell,
  • Suren Chilingaryan,
  • Wonqook Choi,
  • Deseada D. Díaz Barrero,
  • Karol Debowski,
  • Marco Deffert,
  • Martin Descher,
  • Peter J. Doe,
  • Otokar Dragoun,
  • Guido Drexlin,
  • Stephan Dyba,
  • Frank Edzards,
  • Klaus Eitel,
  • Enrico Ellinger,
  • Ralph Engel,
  • Sanshiro Enomoto,
  • Mariia Fedkevych,
  • Arne Felden,
  • Joseph F. Formaggio,
  • Florian Fränkle,
  • Gregg B. Franklin,
  • Fabian Friedel,
  • Alexander Fulst,
  • Kevin Gauda,
  • Woosik Gil,
  • Ferenc Glück,
  • Robin Größle,
  • Rainer Gumbsheimer,
  • Volker Hannen,
  • Norman Haußmann,
  • Klaus Helbing,
  • Stephanie Hickford,
  • Roman Hiller,
  • David Hillesheimer,
  • Dominic Hinz,
  • Thomas Höhn,
  • Thibaut Houdy,
  • Anton Huber,
  • Alexander Jansen,
  • Christian Karl,
  • Jonas Kellerer,
  • Luke Kippenbrock,
  • Manuel Klein,
  • Christoph Köhler,
  • Leonard Köllenberger,
  • Andreas Kopmann,
  • Marc Korzeczek,
  • Alojz Kovalík,
  • Bennet Krasch,
  • Holger Krause,
  • Luisa La Cascio,
  • Thierry Lasserre,
  • Thanh-Long Le,
  • Ondřej Lebeda,
  • Bjoern Lehnert,
  • Alexey Lokhov,
  • Moritz Machatschek,
  • Emma Malcherek,
  • Alexander Marsteller,
  • Eric L. Martin,
  • Matthias Meier,
  • Christin Melzer,
  • Susanne Mertens,
  • Klaus Müller,
  • Simon Niemes,
  • Patrick Oelpmann,
  • Alexander Osipowicz,
  • Diana S. Parno,
  • Alan W.P. Poon,
  • Jose M. Lopez Poyato,
  • Florian Priester,
  • Oliver Rest,
  • Marco Röllig,
  • Carsten Röttele,
  • R.G. Hamish Robertson,
  • Caroline Rodenbeck,
  • Milos Ryšavỳ,
  • Rudolf Sack,
  • Alejandro Saenz,
  • Peter Schäfer,
  • Anna Schaller (née Pollithy),
  • Lutz Schimpf,
  • Klaus Schlösser,
  • Magnus Schlösser,
  • Lisa Schlüter,
  • Michael Schrank,
  • Bruno Schulz,
  • Michal Sefčík,
  • Hendrik Seitz-Moskaliuk,
  • Valérian Sibille,
  • Daniel Siegmann,
  • Martin Slezák,
  • Felix Spanier,
  • Markus Steidl,
  • Michael Sturm,
  • Menglei Sun,
  • Helmut H. Telle,
  • Larisa A. Thorne,
  • Thomas Thümmler,
  • Nikita Titov,
  • Igor Tkachev,
  • Drahoš Vénos,
  • Kathrin Valerius,
  • Ana P. Vizcaya Hernández,
  • Marc Weber,
  • Christian Weinheimer,
  • Christiane Weiss,
  • Stefan Welte,
  • Jürgen Wendel,
  • John F. Wilkerson,
  • Joachim Wolf,
  • Sascha Wüstling,
  • Weiran Xu,
  • Yung-Ruey Yen,
  • Sergey Zadoroghny,
  • Genrich Zeller

DOI
https://doi.org/10.3390/s20174827
Journal volume & issue
Vol. 20, no. 17
p. 4827

Abstract

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The Karlsruhe Tritium Neutrino (KATRIN) experiment aims at measuring the effective electron neutrino mass with a sensitivity of 0.2 eV/c2, i.e., improving on previous measurements by an order of magnitude. Neutrino mass data taking with KATRIN commenced in early 2019, and after only a few weeks of data recording, analysis of these data showed the success of KATRIN, improving on the known neutrino mass limit by a factor of about two. This success very much could be ascribed to the fact that most of the system components met, or even surpassed, the required specifications during long-term operation. Here, we report on the performance of the laser Raman (LARA) monitoring system which provides continuous high-precision information on the gas composition injected into the experiment’s windowless gaseous tritium source (WGTS), specifically on its isotopic purity of tritium—one of the key parameters required in the derivation of the electron neutrino mass. The concentrations cx for all six hydrogen isotopologues were monitored simultaneously, with a measurement precision for individual components of the order 10−3 or better throughout the complete KATRIN data taking campaigns to date. From these, the tritium purity, εT, is derived with precision of −3 and trueness of −3, being within and surpassing the actual requirements for KATRIN, respectively.

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