Research

The future of nuclear disarmament, arms control and non-proliferation efforts relies in multiple ways on innovative technical verification methods to support government and public confidence in treaties and other agreements. Currently, detecting nuclear weapons or fissile material from a distance of tens of meters is a key verification challenge and also important for countering nuclear terrorism threats. Reliable detection methods can also demonstrate the absence of nuclear weapons and fissile material from sites declared as cleaned out or shutdown. 

Typical warhead deployment sites often use large structures like bunkers, adding absorbing media between the sources and potential detectors. Other deployment locations like submarines do not feature heavy shielding, but have limited access. Both limits need to be addressed by new, innovative verification approaches. These could, for example, become relevant to a Central European zone free of nuclear weapons established after the end of Russia's war in Ukraine.

Additional verification challenges include the confirmation of nuclear weapons (is it a weapon or a hoax object), the verification of nuclear weapon test events and, in particular, to determine whether low-yield experiments involve multiplying neutron chain reactions that reach a supercritical level and are banned by agreement or decaying neutron chain reactions at the subcritical level which are allowed.

Ongoing work:

• We develop a “Muon Bunker Telescope” to determine density variations in larger structures as a way to find hidden fissile material. We plan to have only a single detector system to image objects of larger size and rely on muon transmission and absorption measurements.
• Improving existing gamma-spectroscopy based verification systems through machine learning-derived detection parameters and demonstrating feasibility through Gamma spectroscopy measurements using commercially available radiation sources as stand-ins for nuclear warheads.

Planned work:

• Using muon-induced fissions to prove the absence of nuclear weapons and fissile materials. This approach requires Muon-neutron coincidence measurements, to detect incoming muons and neutrons resulting from fission.
• Employing Gamma-gamma coincidence measurements for more specific identification of individual radioactive isotopes in samples with various radioactive elements. Such measurements can significantly improve the identification of weapon test remnants.

Nuclear weapon programs have already created significant legacy humanitarian and environmental contamination by nuclear weapon development, testing and productions. This legacy includes the environmental contamination left behind by nuclear weapon tests and ongoing impacts on local populations of test regions. Most are in countries with limited scientific capabilities. Research is needed to determine adequate handling of this legacy.

The Treaty on the Prohibition of Nuclear Weapons (TPNW) is the first international agreement to take note of the above-mentioned legacy effects, requiring member state, the United Nations and other international organizations in so-called positive obligations to support those affected. Germany is not a treaty member, but plans to also engage with these obligations. A strong research effort is needed to support all such engagement.

Ongoing Work: Moritz is an advisor to the project “Nuclear Justice and Gender in the Sea of Islands”, which is coordinated by Prof. Dr. Benno Fladvad and Dr. Janina Dannenberg. The project intends to work with and for affected communities, survivors of nuclear weapons in the Sea of Islands in order to identify the socio-ecological impacts of nuclear weapons and their interaction with climate changes through a gender lens.

Planned Work: Development of approaches and detectors to monitor radiation levels to enable laypeople in affected regions to determine local near-real-time radiation doses. Currently, limited knowledge on local radioactive contamination exists, and ist often decades out of date. These efforts will make use of the capability to conduct Radiation dose rate measurements (in the environment). In practice, this means we plan to build a drone for that purpose.

The risk and consequences of nuclear weapons are poorly understood, by experts, policy makers and the public – a similar problem has been identified in the field of climate change. Collaboration between physical scientists and behavioral scientists can help to begin to fill this gap. This research area will aim to support efforts to better understand and communicate nuclear weapon effects and escalation dynamics to reduce nuclear dangers. It is well-known the explosion of a single nuclear weapon will have devastating immediate consequences. However, a key issue is what happens next in terms of larger scale and longer term impacts and possible escalation from a single explosion to more widespread and even global nuclear devastation- and how this is imagined and understood. I

Ongoing Work: Virtual reality-based project “Nuclear Biscuit” together with Prof. Weiner (American University and Princeton University) to study the rationality dynamics of escalation from the point of view of a human decision maker.
It is planned to expand the existing project to address different escalation mechanisms using virtual reality experiments. This could include communication between multiple actors (e.g., a virtual Russian and U.S. president), a specific focus on Europe, and a focus on special doctrines like the idea of “escalate to deescalate”.