Heidelberg 2015 – wissenschaftliches Programm

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MS: Fachverband Massenspektrometrie

MS 3: New Mass Spectrometric Methods and Technical Developments

MS 3.8: Vortrag

Montag, 23. März 2015, 18:45–19:00, PH/HS2

Determination of krypton concentration in xenon gas with a quadrupole mass spectrometer following a cold-trap at a temporarily reduced pumping speed — •Alexander Fieguth, Ethan Brown, Gianmarco Bruno, Michael Murra, Sergej Schneider, and Christian Weinheimer — Institut für Kernphysik, WWU, Münster

The removal of trace impurities in xenon gas, as for example the radioactive isotope ⁸⁵Kr, is of viable importance for achieving new sensitivities in particle physics experiments, especially in the field of dark matter search. While the removal of this isotope can be performed by cryogenic distillation down to the sub-ppb level, the detection at this low concentrations is not trivial. A recently improved method (E.Brown et al. JINST 8 (2013) P02011) uses a commercial quadrupole mass spectrometer supported by an auxiliary structure based on a cold trap to achieve sub-ppb sensitivity in measurements on the minute scale and with consumption of only a few milliliters of expensive xenon gas. Additional sensitivity gain is provided by a self-made butterfly valve in front of the pumping system to allow for dynamically manipulate the pumping speed. This method can be used for the characterization of the working performance of the crygonenic distillation column build for the upcoming XENON1T experiment. This work is funded by DFG.