PNNL

Samuel (Sam) Watkins is a physicist in the Detection Physics Group in the Physical Detection Systems and Deployment Division of the National Security Directorate at Pacific Northwest National Laboratory. Watkins is a low-temperature detector physicist, working with transition-edge sensors, microwave kinetic inductance detectors, qubits, and more. Having experience in dark matter and neutrinoless double beta decay experiments, Watkins has worked with a variety of detection technologies and has experience analyzing the rich data from these detectors.

Watkins was previously a Director's Postdoctoral Fellow at Los Alamos National Laboratory. He holds a PhD in physics from the University of California, Berkeley, and a BS in physics from the University of California, Los Angeles.

• Rare event searches
• Low-temperature detector research and development
• Data analysis

• University of California, Berkeley, Doctor of Philosophy, Physics
• University of California, Berkeley, Master of Arts, Physics
• University of California, Los Angeles, Bachelor of Science, Physics

American Physical Society

Recipient of the Director’s Postdoctoral Fellowship at Los Alamos National Laboratory (2023)

“Design Studies Of A Pulsed Quasimonoenergetic 2-keV Neutron Source For Calibration Of Low Threshold Dark Matter Detectors” Other: 2841501. ARXIV: 2410.14722

“Low Energy Backgrounds and Excess Noise in a Two-Channel Low-Threshold Calorimeter”. Other: 2841981. ARXIV: 2410.16510

“Rare multi-nucleon decays with the full data sets of the Majorana Demonstrator”. Other: 2861863. ARXIV: 2412.16047.

“The MAJORANA DEMONSTRATOR experiment's construction, commissioning, and performance” Other: 2865297. ARXIV: 2501.02060.

2024

“Assay-based background projection for the Majorana Demonstrator using Monte Carlo uncertainty propagation” Phys.Rev.C, Nov. 22, 2024. Other 2817703. DOI: 10.1103/PhysRevC.110.055804. ARXIV: 2408.06786.

“Demonstration of the HeRALD superfluid helium detector concept” Phys.Rev.D, Oct. 01, 2024. Other 2679762. DOI: 10.1103/PhysRevD.110.072006. ARXIV: 2307.11877.

“A stress-induced source of phonon bursts and quasiparticle poisoning”. Nature Commun., Jul. 31, 2024. Other: 2132582. DOI: 10.1038/s41467-024-50173-8. ARXIV: 2208.02790.

“Two-Stage Cryogenic HEMT-Based Amplifier for Low-Temperature Detectors” J.Low Temp.Phys., Feb. 06, 2024. Other: 2719269. DOI: 10.1007/s10909-023-03046-1

“Final Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of $^76$Ge to Excited States of $^76$Se”. Preprint: 2024. ARXIV: 2410.03995.

“Light Dark Matter Constraints from SuperCDMS HVeV Detectors Operated Underground with an Anticoincidence Event Selection” Preprint: 2024. Other: 2806813. ARXIV: 2407.08085. DOI: 10.48550/ARXIV.2407.08085

2023

“SPLENDAQ: A Detector-Agnostic Data Acquisition System for Small-Scale Physics Experiments” Journal of Low Temperature Physics, Dec. 22, 2023. DOI: 10.1007/s10909-023-03021-w.

“Beyond-DFT $\textit{ab initio}$ Calculations for Accurate Prediction of Sub-GeV Dark Matter Experimental Reach”. Preprint: Sep. 29, 2023. ARXIV: arXiv:2310.00147v1.

“First Measurement of the Nuclear-Recoil Ionization Yield in Silicon at 100 eV”. Phys.Rev.Lett., Aug. 28, 2023. Other: 2638592. DOI: 10.1103/PhysRevLett.131.091801. ARXIV: 2303.02196.

“Majorana Demonstrator Data Release for AI/ML Applications”. Preprint: Aug. 21, 2023. ARXIV: arXiv:2308.10856v3.

“A portable and monoenergetic 24 keV neutron source based on 124Sb-9Be photoneutrons and an iron filter”. Journal of Instrumentation, Jul. 01, 2023. DOI: 10.1088/1748-0221/18/07/p07018.

“Search for low-mass dark matter via bremsstrahlung radiation and the Migdal effect in SuperCDMS” Physical Review D, Jun. 30, 2023. DOI: 10.1103/physrevd.107.112013.

“Fundamental Symmetries, Neutrons, and Neutrinos (FSNN): Whitepaper for the 2023 NSAC Long Range Plan” . Preprint: Apr. 07, 2023. ARXIV: arXiv:2304.03451v1.

“Quantum Information Science and Technology for Nuclear Physics. Input into U.S. Long-Range Planning, 2023” . Preprint: Feb. 28, 2023. ARXIV: arXiv:2303.00113.

“Athermal Phonon Sensors in Searches for Light Dark Matter”. Dissertation Thesis: Jan. 20, 2023. ARXIV: arXiv:2301.08699v1.

“Constraints on the Decay of ^{180m}Ta”. Journal Article: Physical review letters, 2023. SOURCE-WORK-ID: LAPR-2023-043355. DOI: 10.1103/PhysRevLett.131.152501.

2022

“Neutrinoless Double Beta Decay”. Preprint: Dec. 21, 2022. ARXIV: arXiv:2212.11099.

“Observation of Long-Lived UV-Induced Fluorescence from Environmental Materials Using the HVeV Detector as Developed for SuperCDMS” J.Low Temp.Phys., Oct. 15, 2022. Other: 2610894. DOI: 10.1007/s10909-022-02802-z.

“The level-1 trigger for the SuperCDMS experiment at SNOLAB”. Journal of Instrumentation, Jul. 01, 2022. DOI: 10.1088/1748-0221/17/07/P07010. DOI: 10.48550/arXiv.2204.13002.

“A backing detector for order-keV neutrons” Nucl.Instrum.Meth.A, Jun. 23, 2022. Other: 2048937. DOI: 10.1016/j.nima.2022.166981. ARXIV: 2203.04896.

“Investigating the sources of low-energy events in a SuperCDMS-HVeV detector” Physical Review D, Jun. 22, 2022. DOI: 10.1103/physrevd.105.112006. DOI: 10.48550/arXiv.2204.08038.

“Ionization yield measurement in a germanium CDMSlite detector using photo-neutron sources”. Physical Review D, Jun. 17, 2022. DOI: 10.1103/PhysRevD.105.122002 DOI: 10.48550/arXiv.2202.07043.

“Effective Field Theory Analysis of CDMSlite Run 2 Data”. Preprint: May 24, 2022. ARXIV: arXiv:2205.11683v1.

“A Strategy for Low-Mass Dark Matter Searches with Cryogenic Detectors in the SuperCDMS SNOLAB Facility” Preprint: Mar. 16, 2022. ARXIV: arXiv:2203.08463v2.

“EXCESS workshop: Descriptions of rising low-energy spectra” Journal Article: Feb. 10, 2022. ARXIV: 2202.05097. DOI: 10.21468/scipostphysproc.9.001.

2021

“Constraints on Lightly Ionizing Particles from CDMSlite” Journal Article: Physical Review Letters, Aug. 18, 2021. DOI: 10.1103/PhysRevLett.127.081802.

“Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated Above Ground” Journal Article: Phys.Rev.Lett., Aug. 04, 2021. Other: 1809053. DOI: 10.1103/PhysRevLett.127.061801. ARXIV: 2007.14289.

“Scintillation yield from electronic and nuclear recoils in superfluid $^4$He”. Preprint: Aug. 04, 2021. ARXIV: 2108.02176. DOI: 10.1103/physrevd.105.092005.

“Design and characterization of a phonon-mediated cryogenic particle detector with an eV-scale threshold and 100 keV-scale dynamic range” Journal Article: Phys.Rev.D, Aug. 01, 2021. Other: 1838058. DOI: 10.1103/PhysRevD.104.032010. ARXIV: 2012.12430.

“Performance of a large area photon detector for rare event search applications”. Journal Article: Applied Physics Letters, Jan. 11, 2021. DOI: 10.1063/5.0032372.

2020

“Constraints on low-mass, relic dark matter candidates from a surface-operated SuperCDMS single-charge sensitive detector” Journal Article: Physical Review D, Nov. 13, 2020. DOI: 10.1103/PhysRevD.102.091101.

“Characterizing TES Power Noise for Future Single Optical-Phonon and Infrared-Photon Detectors” Journal Article: Apr. 21, 2020. ARXIV: arXiv:2004.10257. DOI: 10.1063/5.0011130.

“Constraints on dark photons and axionlike particles from the SuperCDMS Soudan experiment” Journal Article: Physical Review D, Mar. 17, 2020. DOI: 10.1103/physrevd.101.052008. ARXIV: arXiv:1911.11905.

2019

“Modeling of Impact Ionization and Charge Trapping in SuperCDMS HVeV Detectors” Journal Article: J Low Temp Phys (2020), Dec. 24, 2019. DOI: 10.1007/s10909-020-02349-x. ARXIV: arXiv:1912.11549.

“Measuring the Impact Ionization and Charge Trapping Probabilities in SuperCDMS HVeV Phonon Sensing Detectors”. Journal Article: Phys. Rev. D 101, 031101 (2020), Oct. 04, 2019. DOI: 10.1103/physrevd.101.031101. ARXIV: arXiv:1910.02162.

2018

“Search for Low-Mass Dark Matter with CDMSlite Using a Profile Likelihood Fit” Journal Article: Phys. Rev. D 99, 062001 (2019), Aug. 28, 2018. DOI: 10.1103/PhysRevD.99.062001. ARXIV: arXiv:1808.09098.

“Production Rate Measurement of Tritium and Other Cosmogenic Isotopes in Germanium with CDMSlite” Journal Article: R. Agnese et al. (SuperCDMS Collaboration), Astropart. Phys., 104 (2019) pp. 1-12, Jun. 19, 2018. ARXIV: arXiv:1806.07043. DOI: 10.1016/j.astropartphys.2018.08.006.

“Energy Loss Due to Defect Formation from $^{206}$Pb Recoils in SuperCDMS Germanium Detectors”. Journal Article: Appl. Phys. Lett. 113, 092101 (2018), May 25, 2018. ARXIV: arXiv:1805.09942. DOI: 10.1063/1.5041457.

“First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector”. Journal Article: Phys. Rev. Lett. 121, 051301 (2018), Apr. 27, 2018. DOI: 10.1103/PhysRevLett.121.051301. ARXIV: arXiv:1804.10697.