Erica Caden

Research Scientist | SNOLAB

Adjunct Faculty |Laurentian, McGill

Abstract

Neutrinoless double beta decay (0νββ) is a hypothetical nuclear process whose observation would have profound implications for particle physics, establishing the Majorana nature of neutrinos and providing direct evidence of lepton number violation. Among candidate isotopes, xenon-136, has emerged as one of the most promising due to its scalability, radiopurity, and versatility in detector design. Recent results from xenon experiments including have significantly improved half-life limits, pushing sensitivities beyond 10^26 years. In parallel, large-scale liquid xenon detectors developed for dark matter searches are increasingly being explored for their sensitivity to double beta decay. Although not optimized for this channel, their ultra-low backgrounds and large target masses provide a powerful complementary approach. Looking ahead, proposed next-generation instruments such as XLZD aim to perform dark matter and rare event searches at unprecedented scales. With significantly increased exposure and improved background control, such detectors could extend sensitivity to 0νββ well into unexplored parameter space. This talk will discuss the physics motivation, experimental challenges, and technological innovations driving the field, as well as the growing synergy between dark matter and double beta decay efforts. The continued progress of xenon-based searches positions them at the forefront of efforts to determine whether neutrinos are their own antiparticles and to probe physics beyond the Standard Model.

Timbits, coffee, tea will be served in STI A before the colloquium.

Dr. Allison Gonsalves
McGill

Abstract

Who gets to be recognized as a physicist? What are the cultural features of physics that render some identities “in-place” while others are deemed “out-of-place”?  In this presentation, I will present an overview of research (mine and others) on equity and identity in physics education research, with a specific focus on the persistent underrepresentation of women in physics and the politics of recognition that perpetuate this. I will discuss the foundations of the field of identity research in physics education and highlight some practical applications of this work. I will conclude with a discussion of future directions for equity research in physics education, with a particular focus on affect and relationality.

Timbits, coffee, tea will be served in STI A before the colloquium.

Audrey Corbeil Therrien
Associate Professor
Department of Electrical & Computer Engineering
Université de Sherbrooke in Québec, Canada

Abstract

Radiation and particle detectors let us observe the universe beyond what our senses can achieve. Scientists come up with new ways to collect information about our universe using detectors to transform particles into electrical signals and digital bits. These novel detectors are more precise, larger and offer much more range than their predecessors, resulting in large amounts of channels and data. For example, the ARGO detector will exploit novel photon-to-digital converters to detect light emission in a liquid argon target. The large surface area (~200 m²) and the immense number of detectors needed to cover this surface at the µm² scale requires the development of a new data acquisition paradigm.

Transmitting raw data continuously to a compute system would be prohibitive both in material and energy costs. My research group develops systems to distribute real-time compression and analysis algorithms along the data acquisition chain including right up at the edge of the detector. This approach presents several challenges with limited computing power and memory availability. We combine small AI models with carefully selected signal processing and compression algorithms to achieve very efficient smart acquisition systems capable of several orders of magnitude data reduction in a few microseconds.

Audrey Corbeil Therrien is an Associate Professor in the Department of Electrical and Computer Engineering at the Université de Sherbrooke in Québec, Canada.  She currently holds the Tier-2 Canada Research Chair in real-time embedded intelligence for ultra-high rate detectors. She has worked at CERN (2015) in Geneva, Switzerland and at the SLAC National Accelerator Laboratory where she held a Banting Fellowship (2018-2020). Her research aims to improve real-time analyses at the edge with the integration of machine learning in high performance radiation instrumentation systems. She is part of several conference committees, and she is co-chair for the 2026 IEEE Nuclear Science Symposium. She has been strongly involved with the promotion of technical and scientific careers for diverse groups with Université de Sherbrooke, SLAC, Stanford University, local non-profits and at several conferences. She received several awards, the 2023 Prix Honoris Genius — Relève of the Ordre des Ingénieurs du Québec and the 2024 IEEE Women in Engineering Leadership Development Travel Grant.

Timbits, coffee, tea will be served in STI A before the colloquium.

Kathryn Hartling
Canadian Nuclear Laboratories(CNL)

Abstract

An overview will be presented of several on-going research projects at Canadian Nuclear Laboratories (CNL) involving the application of muon, gamma, and liquid argon detectors for nuclear security and forensics, as well as contributions to Ac-225 medical isotope production.

Muon tomography leverages naturally-occurring cosmic-ray muon radiation to image target structures. CNL is currently home to four types of muon detectors based on plastic scintillators or Micromegas, including variants that are field deployable or integrate momentum measurement. In a nuclear security context, muon tomography can be used to identify and characterize special nuclear materials or associated shielding structures to support border security as well as nuclear waste management, disarmament, and infrastructure monitoring.

Nuclear forensics examines nuclear or radioactive materials, or other materials contaminated with radionuclides, in the context of legal proceedings. In this field, gamma-ray spectroscopy is a valuable method of characterizing the isotopic composition of materials in a non-destructive way. Coincident-gamma systems can help to isolate isotopic signatures in complex mixtures or high-background measurements. CNL is currently engaged in the development of a field-deployable coincident-gamma detector based on an array of cadmium zinc telluride crystals.

Liquid argon detectors are commonly used in dark matter and neutrino detection experiments, where it has been shown that they can provide excellent discrimination of nuclear and electron recoils. Consequently, LAr detectors are capable of detecting and differentiating neutron and gamma/beta radiation, and it is expected that their efficiencies and gamma energy resolution can exceed current standards for radiation portal monitors deployed for border security. CNL has developed a bench-top LAr detector prototype, and is currently planning for a future field-deployable design.

Ac-225 is a popular medical isotope candidate for targeted alpha therapy, a developmental method of cancer treatment. However, clinical trials are challenging due to low global production of this isotope. CNL is one of only a few locations globally with the ability to produce this material in research scale quantities. Ac-225 is produced by a thorium generator at CNL's Chalk River site, and by cyclotron irradiation of Ra-226 in collaboration with the Sylvia Fedoruk Canadian Center for Nuclear Innovation and Isotope Technologies Munich.

Timbits, coffee, tea will be served in STI A before the colloquium.

Stewart Prager
Princeton University

Abstract

The danger from nuclear weapons is increasing, with a new nuclear competition race underway, a deterioration of the multi-decade arms control regime, and new destabilizing technologies. This talk will overview nuclear weapons and their effects, the current critical situation, feasible steps to reduce the nuclear threat, and a new project initiated to engage physical scientists in advocacy for nuclear threat reduction.

Timbits, coffee, tea will be served in STI A before the colloquium.