Eur. Phys. J. C (2017) 77: 275
https://doi.org/10.1140/epjc/s10052-017-4757-1

Regular Article - Experimental Physics

Removing krypton from xenon by cryogenic distillation to the ppq level

¹ Laboratori Nazionali del Gran Sasso, Assergi, Italy
² Physics Department, Columbia University, New York, NY, USA
³ Nikhef and the University of Amsterdam, Science Park, Amsterdam, Netherlands
⁴ INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L’Aquila, Italy
⁵ Department of Physics and Astrophysics, University of Bologna and INFN-Bologna, Bologna, Italy
⁶ Institut für Physik & Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, Mainz, Germany
⁷ Department of Physics, University of Coimbra, Coimbra, Portugal
⁸ New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
⁹ Physik-Institut, University of Zurich, Zurich, Switzerland
¹⁰ Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm, Sweden
¹¹ Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY, USA
¹² Max-Planck-Institut für Kernphysik, Heidelberg, Germany
¹³ Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot, Israel
¹⁴ Physikalisches Institut, Universität Freiburg, 79104, Freiburg, Germany
¹⁵ Department of Physics and Astronomy, Purdue University, West Lafayette, IN, USA
¹⁶ SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Université de Nantes, Nantes, France
¹⁷ Department of Physics, University of California, San Diego, CA, USA
¹⁸ Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, Münster, Germany
¹⁹ INFN-Torino and Osservatorio Astrofisico di Torino, Torino, Italy
²⁰ Department of Physics and Kavli Institute of Cosmological Physics, University of Chicago, Chicago, IL, USA
²¹ Physics and Astronomy Department, University of California, Los Angeles, CA, USA
²² Department of Physics and Astronomy, Rice University, Houston, TX, USA
²³ LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3, Paris, 75252, France
²⁴ Tritium Laboratory Karlsruhe, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany

^* e-mail: xenon@lngs.infn.it

Received: 16 January 2017
Accepted: 13 March 2017
Published online: 2 May 2017

Abstract

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the -emitter Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon   (parts per quadrillion, ) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe–Thiele approach is described. The system demonstrated a krypton reduction factor of with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN.