Laser-driven generation of muons for material inspection and radiography
During the last 15 years muon-based imaging and inspection has experienced an impressive development. Different techniques and detection methods are currently being studied and some interesting proof-of-principle experiments have been carried out. Arguably, the most spectacular result was the recent identification of a hidden chamber inside the Great Pyramid of Giza, in Egypt.
Thus far, detection techniques rely on the muons generated during the electromagnetic showers initiated by cosmic rays as they propagate through the atmosphere. This readily available source of natural muons presents however some limitations. First, the energy, spectrum, and flux of muons cannot be tuned by the user. Second, the typical flux of muons streaming from the atmosphere is relatively low, of the order of a 1 muon per square centimeter per minute. This low flux naturally implies long acquisition times, sometimes of the order of days. High-power lasers, however, have been demonstrated to provide an ideal platform to generate particle beams of high-quality with much higher fluxes. A significant amount of highly energetic muons (up to 100s per laser shot) can be generated by high-power lasers, such as the Astra-Gemini laser hosted by the Rutherford Appleton Laboratory. In a nutshell, the muons are generated following the cascade initiated by a GeV-scale laser-driven electron beam propagating through a high-Z solid target. Astra-Gemini currently works at a laser shot every 20 seconds, meaning a flux of muons per minute that exceeds by more than 4 orders of magnitude the flux obtainable from cosmic rays propagating through the atmosphere. This number can be further increased if lasers with a higher repetition rate are used. This will make acquisition times shrink by about 1 million times: an inspection that now requires 1 day will be performed in 1 second.
The proposed research project aims at studying laser-driven generation of muons, with the final aim of demonstrating a high-flux and tuneable laser-driven muon source, with the specific intent of exploiting it for material inspection and muon radiography. Dedicated experiments will be carried out at high-power laser systems, including the TARANIS and TARANIS-X lasers hosted by the Queen’s University of Belfast. Optimisation and full characterisation of the muon source will be carried out together of first proof-of-principle experiments of material inspection and radiography.
To be eligible you must be an UK national and hold at least a 2.1 BSc (or equivalent) in Physics or a relevant subject.
How to apply:
Applications should be made through the QUB application portal at the following link: https://dap.qub.ac.uk/portal/user/u_login.php
Please, ensure that your application is directed to the School of Mathematics and Physics. Deadline for applications is the 14th of February 2020. Any queries should be directed to Gianluca Sarri.
The PhD project is sponsored by EPSRC (iCASE studentship programme) and the Defence Science and Technology Laboratory for a duration of 4 years, starting on the 1st of October 2020. The studentship covers Queen’s University tuition fees and a tax-free stipend of ~ £17500 per annum.