Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

Faham, C.H.; Gehman, V. M.; Currie, A.; Dobi, A.; Sørensen, P.; Gaitskell, R. J.

doi:10.1088/1748-0221/10/09/p09010

Cited by 82 publications

(92 citation statements)

References 14 publications

(17 reference statements)

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“…The measured light yield was the λ derived from this χ 2 minimization divided by the two photoelectron correction, 1.175, the light collection efficiency, g 1 , and 2.8 keV. The two photoelectron correction was measured by [38] and assumed to be the same for PIXeY, since the same PMTs were used. The statistical uncertainty on the light yield was calculated from the χ 2 minimization and the systematic uncertainty is dominated by the uncertainty in g 1 .…”

Section: Resultsmentioning

confidence: 99%

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source

et al. 2017

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We calibrate a two-phase xenon detector at 0.27 keV in the charge channel and at 2.8 keV in both the light and charge channels using a 37Ar source that is directly released into the detector. We map the light and charge yields as a function of electric drift field. For the 2.8 keV peak, we calculate the Thomas-Imel box parameter for recombination and determine its dependence on drift field. For the same peak, we achieve an energy resolution, Eσ/Emean, between 9.8% and 10.8% for 0.1 kV/cm to 2 kV/cm electric drift fields.

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Section: Resultsmentioning

confidence: 99%

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source

et al. 2017

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“…The average digitized area of an SPE is ∼100 mV ns [21]. Recently, it has been shown that vacuum ultraviolet photons have a ∼20% probability of generating two photoelectrons at the photocathode of the R8778 PMT [29]. S1 and S2 pulse areas are therefore measured in units of detected photons (phd) rather than photoelectrons.…”

Section: The Lux Experimentsmentioning

confidence: 99%

“…The prior PðM n Þ is the probability of measuring the observed area if there were actually n detected photons in the channel. This is calculated using a single-photon area response probability density function, averaged over all PMT channels, which incorporates the ∼20% probability of xenon scintillation light producing two photoelectrons in the R8778 PMTs [29]. The PðM n Þ prior discourages overfitting by applying a penalty to models composed of many reconstructed photons with improbably small areas.…”

Section: A Photon Timing Algorithmmentioning

confidence: 99%

Liquid xenon scintillation measurements and pulse shape discrimination in the LUX dark matter detector

Akerib¹,

Alsum²,

Araújo³

et al. 2018

Phys. Rev. D

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Weakly interacting massive particles (WIMPs) are a leading candidate for dark matter and are expected to produce nuclear recoil (NR) events within liquid xenon time-projection chambers. We present a measurement of the scintillation timing characteristics of liquid xenon in the LUX dark matter detector and develop a pulse shape discriminant to be used for particle identification. To accurately measure the timing characteristics, we develop a template-fitting method to reconstruct the detection times of photons. Analyzing calibration data collected during the 2013-2016 LUX WIMP search, we provide a new measurement of the singlet-to-triplet scintillation ratio for electron recoils (ER) below 46 keV, and we make, to our knowledge, a first-ever measurement of the NR singlet-to-triplet ratio at recoil energies below 74 keV. We exploit the difference of the photon time spectra for NR and ER events by using a prompt fraction discrimination parameter, which is optimized using calibration data to have the least number of ER events that occur in a 50% NR acceptance region. We then demonstrate how this discriminant can be used in conjunction with the charge-to-light discrimination to possibly improve the signal-to-noise ratio for nuclear recoils.

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“…Photons detected (phd) is a new unit, created by LUX, that compensates for the ∼20% chance that a single photon produces 2 phe in one of the R8778 Hamamatsu PMTs [11]. LUX additionally uses the digital photon counting method called 'spike counting', at low energy, in order to achieve a better resolution of the S1 signal.…”

Section: Introductionmentioning

confidence: 99%

The Present and Future of Searching for Dark Matter with LUX and LZ

Szydagis¹,

collaborations²

2017

Proceedings of 38th International Conference on High Energy Physics — PoS(ICHEP2016)

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The LUX collaboration new results advance the search for dark matter candidate particles in the 4 GeV /c 2 and higher mass range, with a maximal spin-independent 90% CL limit of 2 × 10 −46 cm 2 at 50 GeV /c 2 for its 332 live-day run, following after 6 × 10 −46 cm 2 cross-section for 33 GeV /c 2 mass from the re-analysis of its initial 95 live-day WIMP search data from December 2015. LUX has performed multiple advanced in situ neutron and beta/gamma calibrations of light and charge yields down to 1.1 and 0.7 keV, respectively, in nuclear recoil energy and 1.3 and 0.2 keV in units of electron recoil energy, thereby bypassing the past practice of extrapolating yields from ex situ calibrations or simulation models alone. For this conference proceeding, consequences of the new calibrations for the limit on the interaction cross-sections for low-mass WIMPs will be highlighted. Previous claims of a WIMP signal, from other detectors, are now even more strongly disfavored, assuming isospin invariance and the standard WIMP halo model. Both spin-independent and spin-dependent limits will be discussed, including the recent completion of LUX's 332-liveday blind run. Lastly, we highlight the conceptual design and future plan for its 10-ton-scale, next-generation successor LZ, which plans on achieving < 3 × 10 −48 cm 2 sensitivity for a WIMP of mass 40 GeV /c 2 .

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Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

Cited by 82 publications

References 14 publications

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source

Liquid xenon scintillation measurements and pulse shape discrimination in the LUX dark matter detector

The Present and Future of Searching for Dark Matter with LUX and LZ

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Measurements of wavelength-dependent double photoelectron emission from single photons in VUV-sensitive photomultiplier tubes

Cited by 82 publications

References 14 publications

Calibration of a two-phase xenon time projection chamber with a37Ar source

Calibration of a two-phase xenon time projection chamber with a37Ar source

Liquid xenon scintillation measurements and pulse shape discrimination in the LUX dark matter detector

The Present and Future of Searching for Dark Matter with LUX and LZ

Contact Info

Product

Resources

About

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source

Calibration of a two-phase xenon time projection chamber with a³⁷Ar source