Curriculum Vitae

Samuel L. Watkins

Director’s Postdoctoral Fellow
Los Alamos National Laboratory, P-1 Division

Education

2016 - 2022, University of California, Berkeley

• Ph.D. - Department of Physics
• Thesis: Athermal Phonon Sensors in Searches for Light Dark Matter
  • Alternative link: arXiv:2301.08699 [hep-ex]

2016 - 2018, University of California, Berkeley

• M.A. - Department of Physics

2011 - 2015, University of California, Los Angeles

• B.S. - Department of Physics, Magna Cum Laude
• Minor in Applied Mathematics

Research and Work Experience

2022 - Present, Los Alamos National Laboratory, P-1 Division

• Director’s Postdoctoral Fellow
• Co-mentored by Ralph Massarczyk (P-1) and Steve Elliott (P-1)
• Member of the SPLENDOR dark matter collaboration and the LEGEND neutrinoless double beta decay collaboration
• Developing Python package for interfacing with data acquisition system for online and offline threshold and random triggering for SPLENDOR light dark matter search, as well as preparing the analysis pipeline of this data for the eventual dark matter search
• Contributing to the Python codebase development for the LEGEND experiment, optimizing for analysis of large datasets on high-performance computers
• Studying beyond-standard-model physics applications and sensitivity of the future LEGEND-1000 experiment, contributing to collaboration white paper as part of editorial team
• Setting up a local Linux cluster at P-1 for use with Geant4 simulations and analysis of large datasets
• Working with NEN-1 on extraction of event energies of high activity datasets, with the goal of understanding absolute activities of samples

2017 - 2022, University of California, Berkeley, Department of Physics

• Graduate Student Researcher under Assistant Professor Matt C. Pyle
• Member of SuperCDMS and SPICE/HeRALD dark matter detection collaborations
• Performed low-temperature detector R&D in a state-of-the-art dilution refrigerator, from installation of ultra-sensitive Transition-Edge Sensor (TES) based detectors, setup and readout via SQUIDs, to design and implementation of a passive vibration isolation system to reduce noise from pulse-tube cryocooler vibrations
• Executed a complex and novel light dark matter search analysis (SuperCDMS-CPD DM Search) taking raw data, extracting relevant features, and achieving a world-leading cryogenic dark matter exclusion limit, created a substantial majority of the Python analysis code from scratch, and successfully wrote an academic paper that was accepted by Physical Review Letters and spawned vigorous scientific interest in the community
• Creator and maintainer of QETpy, detprocess, and DarkLim open-source Python packages, which have become pivotal tools for our group and scientific collaborators
• Organized and chaired meetings to develop statistical tools and methods for developing reusable and easily readable tools and providing guidance for collaborators on applicability of statistical techniques

2015 - 2016, PNI Sensor Corporation, Santa Rosa, California

• Physicist and algorithm engineer, working primarily in MATLAB
• Created algorithms to leverage data from onboard phone sensors and GPS in order to provide real time navigation in scenarios of intermittent GPS outages and general improvement upon current location
• Spearheaded Kalman filter-based algorithms using pedestrian dead reckoning data and trilateration of multiple stationary radio-frequency beacons to provide real time indoor locating and performed live tests of the system for potential investors
• Interfaced with the Android API to extract raw sensor data from smartphones and discerned which data were of importance for various applications of sensor fusion algorithms

Talks and Posters

Contributed Talk: Searching for Beyond-Standard-Model Physics with LEGEND-1000

• November 28, 2023, APS DNP Meeting 2023, Waikoloa, HI, USA

Contributed Poster: Overview and Status of the SPLENDOR Experiment

• November 7, 2023, CPAD Workshop 2023, Menlo Park, CA, USA

Invited Talk: Mind the Gap: Light Dark Matter Detection with Narrow-Gap Semiconductors

• October 27, 2023, PCTS Workshop: Quantum Probes of Wave-like and Sub-GeV Dark Matter, from Photonics to Quantum Sensing, Princeton, NJ, USA

Contributed Talk: The LEGEND Experiment for Neutrinoless Double Beta Decay

• September 12, 2023, TeVPA 2023, Napoli, IT

Contributed Poster: Searching for Beyond-Standard-Model Physics with LEGEND-1000

• August 28, 2023, TAUP 2023, Wien, AT

Contributed Talk: Searching for Light Dark Matter with Narrow-gap Semiconductors

• August 28, 2023, TAUP 2023, Wien, AT

Contributed Poster: A Detector-Agnostic Data Acquisition System for Small-Scale Physics Experiments

• July 27, 2023, 20th International Conference on Low Temperature Detectors, Daejeon, KR

Invited Talk: Supernova Neutrino Detection with LEGEND

• June 01, 2023, SNvD 2023@LNGS, L’Aquila, IT

Contributed Talk: Searching for Beyond-Standard-Model Physics with LEGEND-1000

• April 15, 2023, APS April Meeting 2023, Minneapolis, MN, USA

Contributed Talk: Search for Dark Matter induced 180Ta decay in MAJORANA

• April 15, 2023, APS April Meeting 2023, Minneapolis, MN, USA

Contributed Poster: Searching for Light Dark Matter with Narrow-gap Semiconductors - the SPLENDOR Experiment

• March 29, 2023, UCLA Dark Matter 2023, Los Angeles, CA, USA

Contributed Talk: A Generic Data Acquisition System for Multidisciplinary Detector R&D

• November 30, 2022, CPAD Workshop 2022, Stony Brook, NY, USA

Invited Talk: CPD DM Search and Excess Signals

• June 15, 2021, EXCESS Workshop, Virtual

Invited Seminar: A Large-Area Cryogenic PhotoDetector, Applications, and a Light Dark Matter Search

• October 08, 2020, Light Dark Matter Seminar, UT Wien, Virtual

Contributed Talk: R&D for Light Mass Dark Matter Searches with SuperCDMS

• July 22, 2019, 18th International Workshop on Low Temperature Detectors, Milano, IT

Teaching, Mentoring, and Outreach

2021 - 2022, University of California, Berkeley, Department of Physics

• Mentored undergraduate Deborah Lin as part of lab project
• Design and implementation of a passive vibration isolation system for a cryogen-free dilution refrigerator

2020, University of California, Berkeley, Department of Physics

• Mentored Aaron Elersich in undergraduate research project
• Design of an X-ray calibration source taking advantage of Al fluorescence

2019 - 2021, SuperCDMS Collaboration, Graduate Student and Postdoc Organization

• Served as one of four representatives of the graduate students and postdocs in the SuperCDMS Collaboration
• Gave voice to the graduate students’ and postdocs’ thoughts and concerns to the SuperCDMS council
• Periodically sent out polls to the entire organization and summarized/proposed actions based on the contents
• Created an always-available anonymous form for any type of feedback for the representatives to act on

2016 - 2017, University of California, Berkeley, Department of Physics

• Graduate Student Instructor for introductory physics
• Prepared for and taught sections of 20 undergraduate students in physics for 4 two-hour sessions a week while managing graduate student classes and research
• Communicated abstract concepts to beginner students to prepare them for a physics or engineering undergraduate degree
• Designed and implemented grading rubrics for tens of midterm and final exam problems to fairly determine students’ understanding of complex subjects

Publications

Corresponding Author

• S. L. Watkins, “SPLENDAQ: A Detector-Agnostic Data Acquisition System for Small-Scale Physics Experiments”, J. Low Temp. Phys. 214, 133 (2024)
• I. Alkhatib, …, S. L. Watkins, et al. (SuperCDMS Collaboration), “Light Dark Matter Search with a High-Resolution Athermal Phonon Detector Operated above Ground”, Phys. Rev. Lett. 127, 061801 (2021)
• C. W. Fink, S. L. Watkins, et al. (CPD Collaboration), “Performance of a large area photon detector for rare event search applications”, Appl. Phys. Lett. 118, 022601 (2021)

Significant Contributions

• J. Anczarski et al., “Two-Stage Cryogenic HEMT Based Amplifier For Low Temperature Detectors”, J. Low Temp. Phys. 214, 256 (2024)
• F. Ponce et al., “Observation of Long-Lived UV-Induced Fluorescence from Environmental Materials Using the HVeV Detector as Developed for SuperCDMS”, J. Low Temp. Phys. 209, 1172-1179 (2022)
• P. Adari et al., “EXCESS workshop: Descriptions of rising low-energy spectra”, SciPost Phys. Proc. 9, 001 (2022)
• J. S. Wilson et al., “The level-1 trigger for the SuperCDMS experiment at SNOLAB”, J. Instrum. 17, P07010 (2022)
• R. Ren et al., “Design and characterization of a phonon-mediated cryogenic particle detector with an eV-scale threshold and 100 keV-scale dynamic range”, Phys. Rev. D 104, 032010 (2021)
• C. W. Fink, S. L. Watkins et al., “Characterizing TES power noise for future single optical-phonon and infrared-photon detectors”, AIP Adv. 10, 085221 (2020)
• F. Ponce et al., “Modeling of Impact Ionization and Charge Trapping in SuperCDMS HVeV Detectors”, J. Low Temp. Phys. 199, 598–605 (2020)
• F. Ponce et al., “Measuring the impact ionization and charge trapping probabilities in SuperCDMS HVeV phonon sensing detectors”, Phys. Rev. D 101, 031101(R) (2020)

Other Publications

• I. J. Arnquist et al. (MAJORANA Collaboration), “Constraints on the decay of ^180mTa”, Phys. Rev. Lett. 131, 152501 (2023)
• M. F. Albakry et al. (SuperCDMS Collaboration), “First measurement of the nuclear-recoil ionization yield in silicon at 100 eV”, Phys. Rev. Lett. 131, 091801 (2023)
• A. Biekert et al., “A portable and high intensity 24 keV neutron source based on ¹²⁴Sb-⁹Be photoneutrons and an iron filter” (2023), J. Instrum. 18, P07018 (2023)
• M. F. Albakry et al. (SuperCDMS Collaboration), “A Search for Low-mass Dark Matter via Bremsstrahlung Radiation and the Migdal Effect in SuperCDMS”, Phys. Rev. D 107, 112013 (2023)
• M. F. Albakry et al. (SuperCDMS Collaboration), “Investigating the sources of low-energy events in a SuperCDMS-HVeV detector”, Phys. Rev. D 105, 112006 (2022)
• A. Biekert et al. (SPICE/HeRALD Collaboration), “A backing detector for order-keV neutrons”, Nucl. Instrum. Methods Phys. Res. A 1039, 166981 (2022)
• M. F. Albakry et al. (SuperCDMS Collaboration), “Ionization yield measurement in a germanium CDMSlite detector using photo-neutron sources”, Phys. Rev. D 105, 122002 (2022)
• A. Biekert et al. (SPICE/HeRALD Collaboration), “Scintillation yield from electronic and nuclear recoils in superfluid He-4”, Phys. Rev. D 105, 092005 (2022)
• I. Alkhatib et al. (SuperCDMS Collaboration), “Constraints on Lightly Ionizing Particles from CDMSlite”, Phys. Rev. Lett. 127, 081802 (2021)
• D. W. Amaral et al. (SuperCDMS Collaboration), “Constraints on low-mass, relic dark matter candidates from a surface-operated SuperCDMS single-charge sensitive detector”, Phys. Rev. D 102, 091101(R) (2020)
• T. Aralis et al. (SuperCDMS Collaboration), “Constraints on dark photons and axionlike particles from the SuperCDMS Soudan experiment”, Phys. Rev. D 101, 052008 (2020)
• R. Agnese et al. (SuperCDMS Collaboration), “Search for low-mass dark matter with CDMSlite using a profile likelihood fit”, Phys. Rev. D 99, 062001 (2019)
• R. Agnese et al. (SuperCDMS Collaboration), “Production Rate Measurement of Tritium and Other Cosmogenic Isotopes in Germanium with CDMSlite”, Astropart. Phys. 104, 1-12 (2019)
• R. Agnese et al. (SuperCDMS Collaboration), “Energy Loss Due to Defect Formation from Pb-206 Recoils in SuperCDMS Germanium Detectors”, Appl. Phys. Lett. 113, 092101 (2018)
• R. Agnese et al. (SuperCDMS Collaboration), “First Dark Matter Constraints from a SuperCDMS Single-Charge Sensitive Detector”, Phys. Rev. Lett. 121, 051301 (2018)

Preprints and White Papers

• E. A. Peterson, S. L. Watkins, C. Lane, J.-X. Zhu, “Beyond-DFT ab initio Calculations for Accurate Prediction of Sub-GeV Dark Matter Experimental Reach” (2023), arXiv:2310.00147 [hep-ph]
• I. J. Arnquist et al. (MAJORANA Collaboration), “Majorana Demonstrator Data Release for AI/ML Applications” (2023), arXiv:2308.10856 [cs.LG]
• R. Anthony-Petersen et al. (SPICE/HeRALD Collaboration), “Applying Superfluid Helium to Light Dark Matter Searches: Demonstration of the HeRALD Detector Concept” (2023), arXiv:2307.11877 [physics.ins-det]
• B. Acharya et al., “Fundamental Symmetries, Neutrons, and Neutrinos (FSNN): Whitepaper for the 2023 NSAC Long Range Plan” (2023), arXiv:2304.03451 [nucl-ex]
• D. Beck et al., “Quantum Information Science and Technology for Nuclear Physics. Input into U.S. Long-Range Planning, 2023” (2023), arXiv:2303.00113 [nucl-ex]
• C. Adams et al., “Neutrinoless Double Beta Decay” (2022), arXiv:2212.11099 [nucl-ex]
• R. Anthony-Petersen et al., “A Stress Induced Source of Phonon Bursts and Quasiparticle Poisoning” (2022), arXiv:2208.02790 [physics.ins-det]
• M. F. Albakry et al. (SuperCDMS Collaboration), “Effective Field Theory Analysis of CDMSlite Run 2 Data” (2022), arXiv:2205.11683 [astro-ph.CO]
• M. F. Albakry et al. (SuperCDMS Collaboration), “A Strategy for Low-Mass Dark Matter Searches with Cryogenic Detectors in the SuperCDMS SNOLAB Facility” (2022), arXiv:2203.08463 [physics.ins-det]