Jimmy Weeks (They/Them)

Current Research Project:

High Resolution Mapping of Ion Beam Acceleration, Propagation and Energy Deposition Within A Plasma Background

My PhD project is all about exploring Fast Ignition in Inertial Confinement Fusion (ICF) by working with laser-driven ion acceleration. I'm looking into how proton-driven fast ignition can work by researching the ways ion beams accelerate, move, and deposit energy within a plasma environment.  

The core idea is to use Target Normal Sheath Acceleration (TNSA) to create high-energy proton beams that can deliver energy precisely where it’s needed in the centre of an imploding fusion capsule. These proton beams, produced by a high-intensity laser hitting a solid foil target, are especially effective for fast ignition because of their unique energy-deposition characteristics. I’ll be focusing on how the presence of a plasma background affects these beams, to figure out how to make them as effective as possible in real-world conditions. 

To do this, I’ll be using high-repetition rate (multi-Hz) setups with novel set-ups such as liquid sheet targets and automated feedback systems. This setup will let me map out the complex interactions between different variables.  On top of this, I’ll use machine learning techniques, such as Bayesian optimization, to help fine-tune the characteristics of the proton beams. By feeding experimental data into these algorithms, I can quickly identify the optimal settings for factors like beam energy, flux, and focus.

One key challenge is that theoretical models for how protons slow down in plasma don’t quite match up with what we see experimentally, especially at the high fluxes needed for fast ignition. By combining data from experiments with simulations, I hope to build a model that captures how specific beam properties are linked to the conditions we can control experimentally, even with the added complexity of plasma effects.

I’ll be based at Queen’s University Belfast, working under Dr. Charlotte Palmer and Dr. Alex Robinson who is located at the Central Laser Facility, who brings experience in computational and theoretical plasma physics. 

I plan on using the  Particle-In-Cell code ORISIS to run simulations alongside experiments at laser facilities, like the Central Laser Facility, the Extreme Light Infrastructure (ELI) in Europe, the Scottish Centre for the Application of Plasma-based Accelerators (SCAPA), ZEUS in the United States, and the OMEGA Laser Facility. Working in these facilities  will give me the chance to explore different approaches to generating and studying high-energy proton beams. By combining these experimental insights with ORISIS simulations, I hope to get a comprehensive view of how proton beams interact in plasma environments, which is essential for pushing forward the understanding and applications of fast ignition in fusion and beyond.

Biography:

I graduated with an upper second-class Master’s in Physics from the University of York, where I specialised in laser-plasma interactions, focusing on the “Tomographic Characterization of Gas Targets for Laser Wakefield Acceleration” for my final project supervised by Dr Chris Murphy (York Plasma Institute). My academic background in plasma physics, laser physics, and advanced experimental techniques has been built up by hands-on experience gained through internships at national research facilities. At the Central Laser Facility, I interned under Dr. Chris Armstrong, where I developed and characterised X-ray diagnostics for the Extreme Photonics Application Centre (EPAC). This involved calibrating crystal scintillators, creating Python scripts for image processing, and simulating energy deposition with GEANT4 to support high-precision experiments. I also gained experience in the fusion start-up sector at companies like Woodruff Scientific and nTtau Digital Ltd, where I contributed to the creation of a standardised cost framework for fusion reactors. This work involved automating material selection and design processes using neural networks and advanced computing techniques to streamline fusion reactor production. My first industry internship was at the UK Atomic Energy Authority, where I developed VR and data visualisation tools to simulate fusion conditions in the Mega Ampere Spherical Tokamak - Upgrade (MAST-U). This project supported operational monitoring and engineering applications, providing insights into fusion reactor environments. During my undergraduate degree, I was also an Outreach Ambassador, sharing the wonders of science with the public. Using a 16” optical telescope, I introduced local youth groups and community members to deep-sky objects like galaxies and nebulae, fostering excitement about space and physics.

Research Interests:

Laser-driven Ion Acceleration
Fast Ignition Inertial Confinement Fusion
High-repetition rate laser-plasma interactions
Laboratory Astrophysics with high-power lasers

Pure Profile:

https://pure.qub.ac.uk/en/persons/jimmy-weeks 

Supervisors:

Dr Charlotte Palmer (QUB), Dr Alex Robinson (CLF)