Sofie Liljegren (Swedish Defense Research Institute, FOI): Detecting clandestine nuclear explosions using atmospheric radio-xenon

Thursday 24 Apr 2025, 14:00 → 15:00 Europe/Stockholm

90103Å

Title: Detecting clandestine nuclear explosions using atmospheric radio-xenon
Speaker: Sofie Liljegren
Affiliation: Swedish Defense Research Institute, FOI
Time: Thursday 24 April 2025, 1400 to 1500
Location: 90103Å

Abstract:

In this seminar, I will share my journey from academia to my current role as a scientist at the Swedish Defence Research Agency (FOI), where I work on nuclear weapons-related issues.  For many decades, Sweden has played an active role in nuclear disarmament and non-proliferation efforts.  One of the key agreements is the Comprehensive Nuclear-Test-Ban Treaty (CTBT), a multilateral accord signed by 187 countries that prohibits all nuclear weapons testing.  Verifying that the CTBT is being upheld involves a multi-messenger approach, monitoring several concurrent signals that could indicate a secret nuclear explosion at stations placed around the world.  A central part of my work involves analysing real-world data, primarily radio-xenon in the atmosphere, tracing potential source locations through atmospheric transport modelling, and simulating possible scenarios to support treaty verification.  This presentation will focus on the technical methods used for radio-xenon detection and interpretation within the CTBT verification regime.