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Hall, K.

Publications and source records attributed to Hall, K..

5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The EXO-200 detector, part II: auxiliary systems

The EXO-200 experiment searched for neutrinoless double-beta decay of 136 Xe with a single-phase liquid xenon detector. It used an active mass of 110 kg of 80.6%-enriched liquid xenon in an ultra-low background time projection chamber with ionization and scintillation detection and readout. Here, this paper describes the design and performance of the various support systems necessary for detector operation, including cryogenics, xenon handling, and controls. Novel features of the system were driven by the need to protect the thin-walled detector chamber containing the liquid xenon, to achieve high chemical purity of the Xe, and to maintain thermal uniformity across the detector.

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

Spectroscopy of Ba andBa+deposits in solid xenon for barium tagging in nEXO

Progress on a method of barium tagging for the nEXO double beta decay experiment is reported. Absorption and emission spectra for deposits of barium atoms and ions in solid xenon matrices are presented. Excitation spectra for prominent emission lines, temperature dependence, and bleaching of the fluorescence reveal the existence of different matrix sites. A regular series of sharp lines observed in Ba + deposits is identified with some type of barium hydride molecule. Lower limits for the fluorescence quantum efficiency of the principal Ba emission transition are reported. Under current conditions, an image of fewer than or equal to 10 4 Ba atoms can be obtained. Prospects for imaging single Ba atoms in solid xenon are discussed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

Improved measurement of the 2 ν β β half-life of 136 Xe with the EXO-200 detector

In this work, we report on an improved measurement of the 2 ν β β half-life of 136 Xe performed by EXO-200. The use of a large and homogeneous time-projection chamber allows for the precise estimate of the fiducial mass used for the measurement, resulting in a small systematic uncertainty. We also discuss in detail the data-analysis methods used for double- β decay searches with EXO-200, while emphasizing those directly related to the present measurement. The 136 Xe 2 ν β β half-life is found to be T 1 / 2 2 ν β β = 2.165 ± 0.016 ( stat ) ± 0.059 ( sys ) × 10 21 yr. Finally, this is the most precisely measured half-life of any 2 ν β β decay to date.

136Xe↗