@article{weldon_mueller_awe_barbeau_hedges_li_mishra_mattingly_2020, title={Characterization of stilbene's scintillation anisotropy for recoil protons between 0.56 and 10 MeV}, volume={977}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2020.164178}, abstractNote={The scintillation anisotropy of the single-crystal organic scintillator trans-stilbene was characterized for recoil protons between 0.56 and 10 MeV. The light output and pulse shape anisotropies were measured at 11 distinct recoil proton energies for over 168 recoil proton trajectories relative to the crystal axes. The measurements were performed using a neutron scatter kinematic measurement system and quasi-monoenergetic neutron beams produced by the tandem Van de Graaff accelerator at Triangle Universities Nuclear Laboratory (TUNL). The extensive recoil proton directional coverage enables interpolation over both energy and direction to form a complete response function of stilbene’s scintillation anisotropy for the measured energy range.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Weldon, R. A., Jr. and Mueller, J. M. and Awe, C. and Barbeau, P. and Hedges, S. and Li, L. and Mishra, M. and Mattingly, J.}, year={2020}, month={Oct} }
 @article{weldon_mueller_barbeau_mattingly_2020, title={Measurement of EJ-228 plastic scintillator proton light output using a coincident neutron scatter technique}, volume={953}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2019.163192}, abstractNote={The light output function of the fast plastic scintillator EJ-228 was measured using a coincident neutron scatter measurement system and quasi-monoenergetic neutron beams produced by the tandem Van de Graaff accelerator at Triangle Universities Nuclear Laboratory. The measurement of scintillator light output using neutron scatter kinematics provides a model-independent determination of the light output function with quantifiable sources of uncertainty. Consequently, light output measurements performed using this method have a key advantage compared to other techniques: the characterization of the scintillating material depends only on the material itself and not on the size of the detector. This advantage is realized if the light output is defined as the absolute neutron light output relative to the absolute electron light output and two conditions are met: (1) the scintillator volume is fully illuminated and edge effects can be neglected during energy calibration measurements and light output measurements, and (2) the light attenuation length for scintillation photons in the material is long enough that the lowest energy interaction of interest produces a statistically significant number of scintillation photons for an interaction at any position in the scintillator volume. Commonly implemented measurement and analysis techniques for light output characterizations are explored and evidence of bias is provided for characterizations performed by analyzing the full-energy deposition edge of a light output spectrum.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Weldon, R. A., Jr. and Mueller, J. M. and Barbeau, P. and Mattingly, J.}, year={2020}, month={Feb} }
 @article{akimov_an_awe_barbeau_becker_belov_blackston_bolozdynya_cabrera-palmer_chen_et al._2020, title={Sensitivity of the COHERENT experiment to accelerator-produced dark matter}, volume={102}, ISSN={["1550-2368"]}, DOI={10.1103/PhysRevD.102.052007}, abstractNote={The COHERENT experiment is well poised to test sub-GeV dark matter models using low-energy recoil detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the $\pi$-DAR neutrino beam produced by the Spallation Neutron Source. We show how a planned 750-kg liquid argon scintillation detector would place leading limits on scalar light dark matter models, over two orders of magnitude of dark matter mass, for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing structure of a $\pi$-DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background in a time window where signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects, further increasing the discovery potential of CEvNS detectors. Such methods would test the calculated thermal dark matter abundance for all couplings $\alpha'\leq1$ within the vector portal model over an order of magnitude of dark matter masses.}, number={5}, journal={PHYSICAL REVIEW D}, author={Akimov, D. and An, P. and Awe, C. and Barbeau, P. S. and Becker, B. and Belov, V and Blackston, M. A. and Bolozdynya, A. and Cabrera-Palmer, B. and Chen, N. and et al.}, year={2020}, month={Sep} }
 @article{gallina_giampa_retiere_kroeger_zhang_ward_margetak_li_tsang_doria_et al._2019, title={Characterization of the Hamamatsu VUV4 MPPCs for nEXO}, volume={940}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2019.05.096}, abstractNote={In this paper we report on the characterization of the Hamamatsu VUV4 (S/N: S13370-6152) Vacuum Ultra-Violet (VUV) sensitive Silicon Photo-Multipliers (SiPMs) as part of the development of a solution for the detection of liquid xenon scintillation light for the nEXO experiment. Various SiPM features, such as: dark noise, gain, correlated avalanches, direct crosstalk and Photon Detection Efficiency (PDE) were measured in a dedicated setup at TRIUMF. SiPMs were characterized in the range $163 \text{ } \text{K} \leq \text{T}\leq 233 \text{ } \text{K}$. At an over voltage of $3.1\pm0.2$ V and at $\text{T}=163 \text{ }\text{K}$ we report a number of Correlated Avalanches (CAs) per pulse in the $1 \upmu\text{s}$ interval following the trigger pulse of $0.161\pm0.005$. At the same settings the Dark-Noise (DN) rate is $0.137\pm0.002 \text{ Hz/mm}^{2}$. Both the number of CAs and the DN rate are within nEXO specifications. The PDE of the Hamamatsu VUV4 was measured for two different devices at $\text{T}=233 \text{ }\text{K}$ for a mean wavelength of $189\pm7\text{ nm}$. At $3.6\pm0.2$ V and $3.5\pm0.2$ V of over voltage we report a PDE of $13.4\pm2.6\text{ }\%$ and $11\pm2\%$, corresponding to a saturation PDE of $14.8\pm2.8\text{ }\%$ and $12.2\pm2.3\%$, respectively. Both values are well below the $24\text{ }\%$ saturation PDE advertised by Hamamatsu. More generally, the second device tested at $3.5\pm0.2$ V of over voltage is below the nEXO PDE requirement. The first one instead yields a PDE that is marginally close to meeting the nEXO specifications. This suggests that with modest improvements the Hamamatsu VUV4 MPPCs could be considered as an alternative to the FBK-LF SiPMs for the final design of the nEXO detector.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Gallina, G. and Giampa, P. and Retiere, F. and Kroeger, J. and Zhang, G. and Ward, M. and Margetak, P. and Li, G. and Tsang, T. and Doria, L. and et al.}, year={2019}, month={Oct}, pages={371–379} }
 @article{akimov_albert_an_awe_barbeau_becker_belov_blackston_bolozdynya_cabrera-palmer_et al._2019, title={First constraint on coherent elastic neutrino-nucleus scattering in argon}, volume={100}, ISSN={["2470-0029"]}, url={https://publons.com/wos-op/publon/28837310/}, DOI={10.1103/PhysRevD.100.115020}, abstractNote={Coherent elastic neutrino-nucleus scattering (CEvNS) is the dominant neutrino scattering channel for neutrinos of energy $E_\nu < 100$ MeV. We report a limit for this process using data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the Oak Ridge National Laboratory Spallation Neutron Source (SNS) Hg target with $4.2\times 10^{22}$ protons on target. The dataset yielded $< 7.4$ observed CEvNS events implying a cross section for the process, averaged over the SNS pion decay-at-rest flux, of $<3.4 \times 10^{-39}$ cm$^{2}$, a limit within twice the Standard Model prediction. This is the first limit on CEvNS from an argon nucleus and confirms the earlier CsI non-standard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon.}, number={11}, journal={PHYSICAL REVIEW D}, author={Akimov, D. and Albert, J. B. and An, P. and Awe, C. and Barbeau, P. S. and Becker, B. and Belov, V and Blackston, M. A. and Bolozdynya, A. and Cabrera-Palmer, B. and et al.}, year={2019}, month={Dec} }
 @article{weldon_mueller_lynch_schuster_hedges_awe_li_barbeau_mattingly_2019, title={High-precision characterization of the neutron light output of stilbene along the directions of maximum and minimum response}, volume={927}, ISSN={["1872-9576"]}, DOI={10.1016/j.nima.2018.10.075}, abstractNote={The scintillation light output response of stilbene crystals has been measured for protons recoiling along the a, b, and c’ crystalline axes with energies between 1.3 and 10 MeV using neutrons produced with the tandem Van de Graaff accelerator at Triangle Universities Nuclear Laboratory. The proton recoil energy and direction were measured using the coincident detection of neutrons between a stilbene scintillator and an array of EJ-309 liquid scintillators spanning arranged neutron recoil angles. The maximum light output was found to coincide with proton recoils along the a-axis, in disagreement with other published measurements, which reported the b-axis as the direction of the maximum light output. Additional measurements were conducted using two different stilbene crystals to confirm these results: a second measurement using the coincident detection of neutrons; measurements of neutron full energy deposition events along the a and b axes; and measurements of the count rate for 252Cf neutrons traveling along the a and b axes directions. All measurements found that recoils along the a-axis produce the maximum light output.}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Weldon, R. A., Jr. and Mueller, J. M. and Lynch, C. and Schuster, P. and Hedges, S. and Awe, C. and Li, L. and Barbeau, P. and Mattingly, J.}, year={2019}, month={May}, pages={313–319} }