Engineering topics

Grant, C. [Boston University]

Publications and source records attributed to Grant, C. [Boston University].

10 records

DOE OSTI2026

Sensitivity of the CUPID experiment to $0\nu \beta \beta$ decay of 100 Mo

CUPID is a next-generation bolometric experiment to search for neutrinoless double-beta decay ($0\nu \beta \beta$ ) of 100 Mo using Li 2 MoO 4 scintillating crystals. It will operate 1596 crystals at ~10 mK in the CUORE cryostat at the Laboratori Nazionali del Gran Sasso in Italy. Each crystal will be facing two Ge-based bolometric light detectors for α rejection. We compute the discovery and the exclusion sensitivity of CUPID to $0\nu \beta \beta$ in a Frequentist and a Bayesian framework. This computation is done numerically based on pseudo-experiments. For the CUPID baseline scenario, with a background and an energy resolution of 1.0 x 10 –4 counts/keV/kg/yr and 5 keV FWHM at the Q-value, respectively, this results in a Bayesian exclusion sensitivity (90% c.i.) of $\hat{T}_{1/2} > 1.6 \times 10^{27} \ \textrm{yr}$, corresponding to the effective Majorana neutrino mass of $\hat{m}_{\beta \beta } < \ 9.6$ – 28 meV. The Frequentist discovery sensitivity (3σ ) is $\hat{T}_{1/2}= 1.0 \times 10^{27} \ \textrm{yr}$, corresponding to $\hat{m}_{\beta \beta }= \ 12$ – 36 meV.

Alfonso, K. [Virginia Polytechnic Institute and St↗

DOE OSTI2026

Cosmogenic neutron production in water at SNO+

Accurate measurement of the cosmogenic muon-induced neutron yield is crucial for constraining a significant background in a wide range of low-energy physics searches. Although previous underground experiments have measured this yield across various cosmogenic muon energies, SNO+ is uniquely positioned due to its exposure to one of the highest average cosmogenic muon energies at 364 GeV. Using ultrapure water, we have determined a neutron yield of 𝑌 𝑛 = (3.3⁢8$^{+0.23}_{−0.30}$) × 10 −4 cm 2 g −1 𝜇 −1 at SNO+. Comparison with simulations demonstrates clear agreement with the FLUKA neutron production model, highlighting discrepancies with the widely used GEANT 4 model. Furthermore, this measurement reveals a lower cosmogenic neutron yield than that observed by the SNO experiment, which used heavy water under identical muon flux conditions. This result provides new evidence that nuclear structure and target material composition significantly influence neutron production by cosmogenic muons, offering fresh insight with important implications for the design and background modeling of future underground experiments.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2026

Publisher Erratum: A gravity-based mounting approach for large-scale cryogenic calorimeter arrays

In the originally published version of this article, several errors were identified in the author list and acknowledgements section. These have now been corrected as follows: Corrections to the Author List: Barrera has been corrected to Barresi. Copello (affiliation 18) has been corrected to Copello (affiliation 19). F. De Domizio has been corrected to S. Di Domizio. Figueros-Feliciamo has been corrected to Figueroa-Feliciano. Mancarella (affiliations 8, 17) has been corrected to Mancarella (affiliations 8, 18). Manenti (affiliations 18, 19) has been corrected to Manenti (affiliations 19, 20). Mayer (affiliations 3, 20, 31) has been corrected to Mayer (affiliations 3, 21, 31). Pagot has been corrected to Pageot. Puranam (affiliation 20) has been corrected to Puranam (affiliation 21). O. Penek has been corrected to Ö. Penek. L. Pettinacci has been corrected to V. Pettinacci. P. Pirro has been corrected to S. Pirro. Previtale has been corrected to Previtali. Rappoldi (affiliation 18) has been corrected to Rappoldi (affiliation 19). Raselli (affiliation 18) has been corrected to Raselli (affiliation 19). Rizzoli (affiliations 8, 17) has been corrected to Rizzoli (affiliations 8, 18). Rossella (affiliation 18) has been corrected to Rossella (affiliation 19). Correction to the Acknowledgements Section: The following grant numbers were missing and have now been added: This work was supported by NSF-PHY-2412377 and NSF-PHY-1913374. Additionally, on page 11, Section 5, second line, the chemical formula was incorrectly given as Li 2 MO 4 . The correct formula is Li 2 MoO 4 . The original article has been updated to reflect these corrections. The publisher apologizes for the inconvenience.

Alfonso, K. [Virginia Polytechnic Institute and St↗

DOE OSTI2025

Search for Majorana Neutrinos with the Complete KamLAND-Zen Dataset

We present a search for neutrinoless double-beta (0⁢𝜈⁢𝛽⁢𝛽) decay of 136 Xe using the full KamLAND-Zen 800 dataset with 745 kg of enriched xenon, corresponding to an exposure of 2.1 ton yr of 136 Xe. This updated search benefits from a more than twofold increase in exposure, recovery of photo-sensor gain, and reduced background from muon-induced spallation of xenon. Combining with the search in the previous KamLAND-Zen phase, we obtain a lower limit for the 0⁢𝜈⁢𝛽⁢𝛽 decay halflife of 𝑇$^{0⁢𝜈}_{1/2}$ >3.8 ×10 26 yr at 90% CL, a factor of 1.7 improvement over the previous limit. The corresponding upper limits on the effective Majorana neutrino mass are in the range 28–122 meV using phenomenological nuclear matrix element calculations.

Abe, S. [Tohoku University] (ORCID:000000022110513↗

DOE OSTI2025

First Evidence of Solar Neutrino Interactions on 13 C

The SNO+ Collaboration reports the first evidence of 8 B solar neutrinos interacting on 13 C nuclei. The charged current interaction proceeds through 13 C +𝜈 𝑒 → 13 N+𝑒 − which is followed, with a 10 minute half life, by 13 N → 13 C +𝑒 + +𝜈 𝑒 . The detection strategy is based on the delayed coincidence between the electron and the positron. Evidence for the charged current signal is presented with a significance of 4.2⁢𝜎. Using the natural abundance of 13 C present in the scintillator, 5.7 metric tons of 13 C over 231 days of data were used in this analysis. The 5.6$^{+3.0}_{−2.3}$ observed events in the data set are consistent with the expectation of 4.7$^{+0.6}_{−1.3}$ events. This result is the second real-time measurement of CC interactions of 8 B neutrinos with nuclei and constitutes the lowest energy observation of neutrino interactions on 13 C generally. This enables the first direct measurement of the CC 𝜈 𝑒 reaction to the ground state of 13 N , yielding an average cross section of (16.1$^{+8.5}_{−6.7}$⁢(stat.)$^{+1.6}_{−2.7}$⁢(syst.))×10 −43 cm 2 over the relevant 8 B solar neutrino energies.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2025

Publisher Erratum: CUPID, the Cuore upgrade with particle identification

Publisher Erratum: Eur. Phys. J. C (2025) 85:737 https://doi.org/10.1140/epjc/s10052-025-14352-1 The author M. Pavan (affiliations 9 and 10) was missing from the published author list. The online version of the article has been updated to include the author. Additionally, affiliations 4 and 17 have been corrected to reflect the proper institutional order. The publisher apologizes for the inconvenience caused.

Alfonso, K. [Virginia Polytechnic Institute and St↗

DOE OSTI2025

A gravity-based mounting approach for large-scale cryogenic calorimeter arrays

Cryogenic calorimeters are among the leading technologies for searching for rare events. The CUPID experiment is exploiting this technology to deploy a tonne-scale detector to search for neutrinoless double-beta decay of 100 Mo. The CUPID collaboration proposed an innovative approach to assembling cryogenic calorimeters in a stacked configuration, held in position solely by gravity. This gravity-based assembly method is unprecedented in the field of cryogenic calorimeters and offers several advantages, including relaxed mechanical tolerances and simplified construction. To assess and optimize its performance, we constructed a medium-scale prototype hosting 28 Li 2 MoO 4 crystals and 30 Ge light detectors, both operated as cryogenic calorimeters at the Laboratori Nazionali del Gran Sasso (Italy). Despite an unexpected excess of noise in the light detectors, the results of this test proved (i) a thermal stability better than ±0.5 mK at 10 mK, (ii) a good energy resolution of Li 2 MoO 4 cryogenic calorimeters, (6.6 ± 2.2) keV FWHM at 2615 keV, and (iii) a Li 2 MoO 4 light yield measured by the closest light detector of 0.36 keV/MeV, sufficient to guarantee the particle identification requested by CUPID.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2025

CUPID, the Cuore upgrade with particle identification

CUPID, the CUORE Upgrade with Particle Identification, is a next-generation experiment to search for neutrinoless double beta decay (0 νββ ) and other rare events using enriched Li 2 100 MoO 4 scintillating bolometers. It will be hosted by the CUORE cryostat located at the Laboratori Nazionali del Gran Sasso in Italy. The main physics goal of CUPID is to search for 0 νββ of 100 Mo with a discovery sensitivity covering the full neutrino mass regime in the inverted ordering scenario, as well as the portion of the normal ordering regime with lightest neutrino mass larger than 10 meV. With a conservative background index of 10 −4 cts/(keV·kg·yr), 240 kg isotope mass, 5 keV FWHM energy resolution at 3 MeV and 10 live-years of data taking, CUPID will have a 90% C.L. half-life exclusion sensitivity of 1.8 · 10 27 yr, corresponding to an effective Majorana neutrino mass ( m ββ ) sensitivity of 9–15 meV, and a 3σ discovery sensitivity of 1 · 10 27 yr, corresponding to an m ββ range of 12–21 meV.

Alfonso, K. [Virginia Polytechnic Institute and St↗

DOE OSTI2025

Reactor antineutrino directionality measurement with the PROSPECT-I detector

The PROSPECT-I detector has several features that enable measurement of the direction of a compact neutrino source. Here, in this paper, a detailed report on the directional measurements made on electron antineutrinos emitted from the High Flux Isotope Reactor is presented. With an estimated true neutrino (reactor to detector) direction of φ = 40.8° ± 0.7° and θ= 98.6° ± 0.4°, the PROSPECT-I detector is able to reconstruct an average neutrino direction of φ = 39.4° ± 2.9° and θ = 97.6° ± 1.6°. This measurement is made with approximately 48 000 Inverse Beta Decay signal events and is the most precise directional reconstruction of reactor antineutrinos to date.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2024

Measurement of the B 8 solar neutrino flux using the full SNO + water phase dataset

The SNO+ detector operated initially as a water Cherenkov detector. The implementation of a sealed cover gas system midway through water data taking resulted in a significant reduction in the activity of 222 Rn daughters in the detector and allowed the lowest background to the solar electron scattering signal above 5 MeV achieved to date. This paper reports an updated SNO+ water phase 8 B solar neutrino analysis with a total livetime of 282.4 days and an analysis threshold of 3.5 MeV. The 8 B solar neutrino flux is found to be (2.3⁢2$^{+0.18}_{-0.17}⁢$(stat)$^{+0.07}_{-0.05}$⁢(syst))×10 6 cm -2 s -1 assuming no neutrino oscillations, or (5.3⁢6$^{+0.41}_{-0.39}⁢$(stat)+$^{0.17}_{-0.16}$⁢(syst))×10 6 cm -2 s -1 assuming standard neutrino oscillation parameters, in good agreement with both previous measurements and standard solar model calculations. The electron recoil spectrum is presented above 3.5 MeV.

79 ASTRONOMY AND ASTROPHYSICS↗