Inertial Confinement Fusion

Supervisor:      Dr Grigory Kagan

When the mean-free-path is comparable to the plasma size, the particle distribution is no longer Maxwellian. In turn, for a charged particle, the mean-free-path scales as the square of this particle energy, so the tail of their distribution can be driven away from thermodynamic equilibrium even if the bulk particles are Maxwellian. It is the tail ions and electrons that are mostly responsible for fusion reactions and hard X-ray emission from HED plasmas. This project will elucidate the non-trivial connection between the kinetic and nuclear/radiation physics.

Supervisor:    Dr Ellie Tubman

Type:                Experimental

Funding:          Subject to contract but in late stages of development

The extreme environment created by a laser-produced plasma is conducive to generating magnetic fields. However, these fields may then influence the overall plasma dynamics, affecting energy transport and producing instabilities. Magnetic fields are predicted to be occurring within inertial confinement fusion (ICF) targets, but their potential impact on the heating of the fusion fuel is less well understood. This PhD project will be conducting and analysing data from experiments using laser facilities worldwide, such as the National Ignition Facility (NIF), Omega and Orion, to give insights into the fields generated and their impact on plasma dynamics. This project will help inform the ICF fusion campaigns, but also assist in our understanding of related astrophysical phenomena.

Supervisor:            Prof. J. Chittenden

Type:                        Computational and theoretical (plus interaction with experimentalists)

Funding:                  Subject to contract but in late stages of development

Magnetic fields play a significant role in a broad range of High Energy Density Plasma experiments including Inertial Confinement Fusion through electromagnetic forces and modified heat flow. Such effects are important in experiments on the National Ignition Facility and other large laser facilities as well as large pulsed power generators. The project will make use of 3D magneto-hydrodynamic simulations to predicts the effects of magnetic fields on the performance of a range of experiments related to Inertial Fusion using direct drive, indirect drive and magnetic drive as well as Laboratory Astrophysics and material science applications.

A PhD project for the EPSRC Prosperity Partnership October2024
Inertial Fusion Energy: Optimising High Energy Density Physics in Complex Geometries
Supervised by Prof. J. Chittenden (Imperial College)

First Light Fusion are proposing the construction of Machine 4 (M4) as a demonstrator scale facility for their approach to impact driven inertial fusion energy. If built, M4 will be the largest pulsed power facility in the world providing unique capabilities for the exploration of potential routes to inertial fusion energy as well as for the study of fundamental physics within extreme states of matter.
Impact driven inertial fusion experiments on M4 will make use of magnetically accelerated flyer plates, coupled to a shock amplifier and then a fusion target. The flyer plate technique has been established over many years of research at Sandia National Laboratory on the ‘Z’ generator and smaller scale pulsed power machines. Scaling of flyer plate designs to the velocities and sizes required for impact fusion studies is an active area of computational study. Of particular interest is how such flyers will operate at the higher currents and longer acceleration time scales on M4 compared to Z.

The potential benefits of M4 for fundamental science were highlighted at a recent meeting at the Royal Society. These include opacity studies relevant to the formation and evolution of stars, studies of magnetic reconnection in the magnetosphere, the solar surface and in colliding stars, studies of nuclear astrophysics and the abundance of isotopes in the universe, investigations of processes forming heavy elements in colliding neutron stars and supernovae and studies of the material states at the centre of gas giant planets as well the Earth. High impact publications in each of these areas have recently come from academic access experiments on existing large scale HEDP facilities including NIF, Z and Omega. M4 would provide the opportunity to scale up such concepts to larger sizes and potentially to higher energy density and fusion yields.

In this PhD project we will explore the potential for M4 to push the boundaries of high energy density physics, by modelling the performance scaling of a series of different pulsed power loads on M4. These include but are not limited to, flyer plates, imploding wire array X-ray sources and dynamic material compression in planar targets as well as imploding liners. Simulation predictions will be grounded by our experience of simulating experiments at the scales currently accessible on Magpie, M3 and Z.

The project will make use of the radiation hydrodynamics and MHD tools developed at Imperial College and at First Light Fusion and in addition will exploit the expertise in Machine Learning within the partnership at First Light Fusion and Machine Discovery as well as the academic partners. ML techniques will be utilised in three aspects of the project work. One is in the use of existing experimental data to constrain MHD codes through the use of ML techniques to allow simultaneous comparison of multiple synthetic diagnostics outputs with observations. Another use is to partially automate the design optimisation process for the various pulsed power targets. This automation can then be enhanced through the development of reduced models for microphysics processes that can be embedded within large scale MHD simulations to expedite large numbers of ensemble calculations.

Supervisor:        Dr Grigory Kagan

Different ion species communicate through collisions (micro-level) in a peculiar way. One of the most intriguing macro-physics consequences is that strong gradients, such as occurring in shocks, can separate species in an initially homogeneous ionic mixture and perturb the relative species concentrations. Analysis of the resulting shock structure can shed light into some mysteries of relative behavior of deuteron and triton ions in laser-driven implosions.

PhD project for October 2024 - supervisor Dr Grigory Kagan

When the plasma becomes dense one can no longer distinguish the binary acts of collisions; a new approach need to be developed for understanding the micro-physics. This is the case in the warm-dense-matter regimes relevant to many astrophysical and laboratory plasmas. Of particular interest is the diffusion and thermal conduction. This project will aim at the very basic plasma physics; new many-body kinetic methods will be utilized to gain an insight into how the non-ideal plasma transport is different from the conventional, ideal case