Online proton range verification is a rapidly emerging field characterised by its ability to reduce the error margins during proton beam therapy, as it is patient-specific and in vivo. In particular, secondary prompt gamma detection is a promising tool to monitor the dose delivery. The present research evaluates the capability of a HEXITEC detector to identify the prompt gammas produced during proton beam therapy, and assesses its potential for online range verification. To achieve this, the detector is placed at one side of a water phantom, which is irradiated at different proton energies in the University College London Hospital Proton Centre. For further analysis, Monte Carlo simulations are performed using Geant4 and the same geometry as the experiment. The results show that HEXITEC has the potential to be part of a detection system that could identify secondary prompt gammas within the secondary field produced inside the target, allowing for the in-detector discrimination of these particles via cluster size analysis. The comparison between data sets shows that there is a high level of accuracy between the model and the experimental measurements in terms of secondary flux and charge diffusion inside the detector, which poses the model as a fundamental tool for future optimisation studies.

The materials used in detection of high energy photons are of primary importance in the construction of efficient, cost effective and sensitive detectors. Current research into Perovskites for solar cell technology has stimulated interest in their potential alternative uses, one of which is in direct photon conversion radiation detectors, owed primarily to their high-Z elemental composition twinned with exceptional charge carrier transport properties. Here, the Perovskite CsPbBr 3 has been synthesised through solution growth. The raw CsPbBr 3 was a granular powder which was formed into disks of 8 mm diameter and 1-2 mm thickness by two methods: 1). the powders were pressed into pellets using a hydraulic press or 2). sealed in a quartz ampoule under vacuum and then melted and quenched to form a polycrystalline solid which was cut to size. Metallic contacts were deposited on the front and back faces to permit charge collection. The results from the pressed devices are promising, particularly given that the production method is cost effective, repeatable and scalable. The solid-from-melt devices show similar performance but further development is required to optimise the production method.

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