Using radon-222 decay chain to observe the behaviour of single atoms in EXO-200, and the progress of tagging single barium atoms in xenon-136

by Brian Mong (Laurentian University)

Tuesday 30 Jun 2015, 12:30 → 13:30 US/Pacific

Marin (bldg 41, room 1154) (SLAC)

The radon decay chain is a background source in EXO-200, a neutrinoless double beta decay (0νββ) search experiment in xenon-136. This chain can also be used to make many interesting measurements. The EXO collaboration is investigating a method to eliminate backgrounds in the 0νββ search by tagging the daughter barium atom/ion. The motions of individual atoms/ions have been studied by correlating decays in the radon-222 chain. We have measured the fraction of ions produced in an alpha and beta decay in this chain, and have made the first measurement of the ion mobility of polonium-218 in LXe using this novel technique [1]. This work provides some information relevant to tagging, as well as potential calibration techniques that may be implemented in nEXO. In addition, the EXO collaboration is looking at several methods of tagging barium. Results using laser induced fluorescence spectroscopy of barium trapped in solid xenon shows great promise and will also be discussed [2]. [1] http://arxiv.org/abs/1506.00317 [2] http://arxiv.org/abs/1410.2624

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