Ethan W. Todd

Education

1. Candidate, Ph.D. Physics

   Fall 2023–Present (expected Fall 2026)

   University of Michigan · Ann Arbor, MI

   Advisors: Prof. Igor Jovanovic, Prof. James Wells

   Winter 2025 M.S. Physics

2. B.S. Physics

   Fall 2020–Spring 2023

   Florida State University · Tallahassee, FL Summa Cum Laude

   Honors Thesis: Study of Displaced Vertex Tagging with the CMS Experiment

   Advisor: Prof. Ted Kolberg

3. Foundational Coursework

   Fall 2018–Spring 2020

   Emory University · Atlanta, GA

Research Experience

1. Graduate Research Aide

   Summer 2026–Present

   Low Energy Physics Group, Argonne National Laboratory · Lemont, IL

   Measurement of the ³⁷Cl(α, n)⁴⁰K Cross Section

   Supervisor: Dr. Daniel Santiago-Gonzalez

   • Performed experimental measurements of the ³⁷Cl(α, n)⁴⁰K reaction using the Multi-Sampling Ionization Chamber (MUSIC) at the ATLAS accelerator facility at Argonne National Laboratory.
   • Developed an event reconstruction algorithm for prior MUSIC data that performs offline time synchronization of four digitizers via analysis of the time structure of the ³⁷Cl beam, and uses CUDA-accelerated time sorting to greatly increase data-processing throughput.
   • Currently searching for ³⁷Cl(α, n)⁴⁰K reaction events in a newly acquired MUSIC dataset while investigating methods to improve the quality of the prior dataset, including by performing unsupervised classification with ML clustering algorithms.

2. Graduate Student Researcher

   Summer 2024–Present

   Applied Nuclear Science Group, University of Michigan · Ann Arbor, MI

   Pulse Shape Discrimination in YAP:Ce via Machine Learning

   • Compared α and γ-ray discrimination capabilities of charge comparison/shape indicator to several machine learning methods: random forests, gradient boosting, XGBoost, and multilayer perceptrons.
   • Quantifed the performance of each method using receiver operating characteristic curves, and demonstrated the substantial advantage of machine learning over traditional methods.
   • Applied the XGBoost model to proof-of-concept mixed field radiation environments consisting of ²⁴¹Am and ¹³⁷Cs or ²⁴¹Am and ⁶⁰Co, and demonstrated that known spectral features of ²⁴¹Am, ¹³⁷Cs, and ⁶⁰Co are correctly classified.

   Precision Measurements of ⁷²Ge(n, γ) at Thermal Energies

   • Utilized the Ohio State Nuclear Reactor Laboratory thermal neutron beam facility to perform new measurements of ⁷²Ge(n, γ)⁷³Ge gamma-ray transition energies with a focus on the 68.75 keV final-state transition.
   • Used a position-sensitive H3D M400 CdZnTe detector to measure low-energy gamma-ray interactions with event-by-event position sensitivity.
   • Developed custom analysis code to select single-scatter events near the detector surface, reducing the Compton background and improving sensitivity in the low-energy region.
   • Provided an independent measurement of the 68.75 keV gamma-ray energy in order to verify a separate UZH/PSI gamma-ray measurement and further support the validity of a recent high 254 eV_nr germanium ionization-yield result.

3. Undergraduate Student Researcher

   Fall 2021–Summer 2023

   CMS Group, Florida State University · Tallahassee, FL

   Search for BSM Long-lived Particles

   Advisor: Prof. Ted Kolberg

   • Utilized deep neural network machine learning to search for beyond the Standard Model long-lived particles in data from the CMS Experiment.
   • Trained ML models on Monte Carlo data with varying signal (mass, lifetime) and background (t, b physics) to verify their ability to identify displaced vertices independently of the particular physics.
   • Investigated the most effective parameters of ML models and verified physics-based expectations.

   Silicon Sensor Quality Control

   Advisor: Prof. Rachel Yohay

   • Conducted process quality control (PQC) testing for the CMS High Granularity Calorimeter (HGCAL) to monitor the quality and stability of the silicon sensor production process.
   • Analyzed and presented PQC results to the CMS HGCAL sensor testing group.
   • Helped create and implement a standardized testing procedure at FSU.

4. Undergraduate Student Researcher

   Fall 2018–Fall 2020

   WW Astrochemistry Group, Emory University · Atlanta, GA

   Advisor: Prof. Susanna Widicus Weaver

   • Performed millimeter/submillimeter spectroscopic measurements of desorbed astrophysical ice analogs.
   • Conducted proof-of-concept millimeter/submillimeter spectroscopic measurements of H₂O and D₂O binding energy, sublimation enthalpy, and sublimation entropy.

Publications

1. Super-Lindhard Ionization from 254 eV_nr Nuclear Recoils in Germanium

   A. R. L. Kavner, E. Todd, M. Babicz, et al.

   2026 under review

2. Leakage Current of High-Fluence Neutron-Irradiated 8" Silicon Sensors for the CMS Endcap Calorimeter Upgrade

   CMS HGCAL Collaboration

   2026 under review

3. Digital Pulse Processing for Mixed-Field Ionizing Radiation Detection in Rare-Event Nuclear Experiments

   V. Fondement, J. Bae, F. Rahman, et al.

   Fusion Science and Technology 2026 in press

4. Updated ^78mBr 2⁻→1⁺ Lifetime from Isomeric Decay Cascade in Active Target

   V. Fondement, E. Todd, I. Jovanovic

   Nuclear Physics A 2026 doi:10.1016/j.nuclphysa.2026.123485

5. Machine Learning-Enabled Pulse Shape Discrimination in YAP:Ce

   E. Todd, V. Fondement, I. Jovanovic

   Nuclear Instruments and Methods in Physics Research Section A 2026 doi:10.1016/j.nima.2026.171883

6. Light Output-Dependent Integration Gating for Optimized Pulse Shape Discrimination

   C. Graham, E. Todd, C. Wilson, et al.

   Nuclear Instruments and Methods in Physics Research Section A 2026 doi:10.1016/j.nima.2026.171521

7. Millimeter/Submillimeter Spectroscopic Detection of Desorbed Ices: A New Technique in Laboratory Astrochemistry

   K. Yocum, H. Smith, E. Todd, et al.

   The Journal of Physical Chemistry A 2019 doi:10.1021/acs.jpca.9b04587

Presentations

1. Machine Learning-Enabled Pulse Shape Discrimination in Fast Inorganic Scintillators

   E. Todd, V. Fondement, I. Jovanovic

   ANL PSE Student Lunch Talk Summer Series, Lemont, IL 2026

2. Particle Identification in Fast Inorganic Scintillators via Machine Learning

   E. Todd, V. Fondement, I. Jovanovic

   Fall Meeting of the Eastern Great Lakes Section of the American Physical Society, Ypsilanti, MI 2025

3. Investigation of Anomalously High Ionization Produced by Low Energy Nuclear Recoils in Germanium (poster)

   E. Todd, I. Jovanovic

   DOE NNSA Office of Defense Nuclear Nonproliferation R&D University Program Review, Gainesville, FL 2025

4. Process Quality Control for HGCAL at Florida State University (poster)

   E. Todd, A. A. Kadhim, N. Bower, et al.

   89th Annual Meeting of the Southeastern Section of the American Physical Society, Oxford, MS 2022

5. A Novel Use of Rotational Spectroscopy for Studying Characteristics of Desorbed Interstellar Ice Analogs (poster)

   E. Todd, K. Yocum, P. Gerakines, et al.

   Emory SURE 2019 Symposium, Atlanta, GA 2019

Teaching Experience

1. Lead Graduate Student Instructor

   Fall 2025–Winter 2026

   University of Michigan · Ann Arbor, MI

   • Oversee 30 graduate student instructors teaching general physics laboratories with a total enrollment of 1800 undergraduate students.
   • Edit and maintain the laboratory manuals and Jupyter notebook worksheets used in the course.
   • Manage the course information and organization via Canvas.
   • Arbitrate student and graduate student instructor concerns.

2. Graduate Student Instructor

   Fall 2023–Spring 2025

   University of Michigan · Ann Arbor, MI

   • Spring 2025 Physics 251, Fundamental Physics for the Life Sciences II Lab
   • Fall 2024 Physics 121, Physics for Architects Lab
   • Fall 2023–Winter 2024 Physics 241, General Physics II Lab

3. Physics Learning Assistant

   Spring 2022

   Florida State University · Tallahassee, FL

   PHY 2049C, General Physics B

4. Laboratory Teaching Assistant

   Fall 2019

   Emory University · Atlanta, GA

   CHEM 150L, Structure and Properties Lab

Honors and Awards

• Winter 2026

  Marcellus L. Wiedenbeck Teaching Award

  Awarded for exemplifying outstanding teaching abilities.

• Winter 2026

  Rackham Outstanding Graduate Student Instructor Award

  Awarded for demonstrating extraordinary dedication and excellence as a teacher.

• Spring 2023

  Phi Beta Kappa Society

• Spring 2023

  Joseph Lanutti Undergraduate Research Award

  Awarded for third place in the FSU physics departmental poster presentation contest.

• Fall 2022

  Evelyn and John Baugh Research Presentation Scholarship

  Awarded to travel and present research at SESAPS.

• Spring 2022

  Anna Runyan Undergraduate Endowment

  Awarded for outstanding academic success in physics.

Grants

• Fall 2025

  NSUF Rapid Turnaround Experiment Grant

  Awarded to conduct precision measurements of Ge gamma-ray cascades at the Ohio State University Nuclear Reactor Laboratory.

• Fall 2025

  Rackham Graduate Student Research Grant

  Awarded to conduct research at the Paul Scherrer Institute on the ionization yield of high-purity germanium detectors.

Skills