The first national UK proton beam therapy centre opened at The Christie NHS Foundation Trust in 2018, which alongside University College London Hospitals NHS Foundation Trust (UCLH) proton beam therapy centre, is expected to treat approximately seven-hundred and fifty patients per year at service ramp up.

The aim of this editorial is to share with a wider audience the role of a Band 6 proton senior treatment radiographer working in a national NHS service and future developments of the service. Prior to the service being clinical, a range of processes were followed, including the creation of quality documents, departmental training and end-to-end testing, with the first patient receiving treatment in December 2018.

Proton senior radiographers are responsible for the delivery of safe and accurate radiotherapy and ensuring a smooth patient pathway, through a multi-collaborative team approach. Although there are key differences between proton and photon radiotherapy, the fundamental aspects, including radiation principles, governance and patient advice are the same. The training package for proton senior radiographers includes an individual local induction as part of the proton education and competency framework, which incorporates practical learning, including clinical supervision and workshops, plus audio-visual presentations and workbooks to complete.

Future developments of proton beam therapy include proton arc therapy and flash therapy, alongside educational developments, such as training the future workforce and advanced practice consultant radiographer roles. Shared learning through multi-collaboration of international proton beam therapy centres is crucial to improve care for future service users.

We observe experimentally periodic proton beam filamentation in laser-produced dense plasma using multilayered (CH–Al–CH) sandwich targets. The accelerated MeV proton beams from these targets exhibit periodic frozen filaments up to 5–10 µm as a result of resistive Weibel instabilities in the expanding plasma. The evolution of strong self-generated resistive magnetic fields at the targets interface is attributed to such plasma effects, which are supported, by our theory and simulations. We suggest that the resistive Weibel instability could be effectively employed to understand the evolution of magnetic fields in laser-generated plasma in the astrophysics scenario or the advanced fast igniter approach of the inertial confinement fusion.

The ultrafast charge dynamics following the interaction of an ultra-intense laser pulse with a foil target leads to the launch of an ultra-short, intense electromagnetic (EM) pulse along a wire connected to the target. Due to the strong electric field (of the order of $\text{GV m}^{-1}$) associated to such laser-driven EM pulses, these can be exploited in a travelling-wave helical geometry for controlling and optimizing the parameters of laser accelerated proton beams. The propagation of the EM pulse along a helical path was studied by employing a proton probing technique. The pulse-carrying coil was probed along two orthogonal directions, transverse and parallel to the coil axis. The temporal profile of the pulse obtained from the transverse probing of the coil is in agreement with the previous measurements obtained in a planar geometry. The data obtained from the longitudinal probing of the coil shows a clear evidence of an energy dependent reduction of the proton beam divergence, which underpins the mechanism behind selective guiding of laser-driven ions by the helical coil targets.

High-intensity lasers are an effective source for the acceleration of high-energy particles. Using different interaction configurations, such facilities can be optimized for the acceleration of electrons, protons, heavy ions, high-energy photons, or neutrons. The shielding of these facilities to ensure the safety of personnel has always been a critical requirement and is a fundamental step within the design phase. The knowledge of radiation source terms through both experiments and modelling is now well understood and for the most part can be dealt with through the use of shielding and specialized beam dumps. Unlike most other particle accelerators most high-power laser facilities are still accessed by personnel post shot with little or no remote handling capabilities. As a result, the secondary activation and control of components that lie around the interaction is of great importance to safety. In this paper, we present a 10 year history of activation data on the Vulcan petawatt facility and discuss the primary sources of activation and the potential impact on future laser facilities.

The study of radiation fields around the cyclotron roomwas carried out for the Proton-Therapy-Center in Prague (Czech Republic).The 230 MeV proton cyclotron will be installed there as well asadditional components located along the beampath. The ambient doseswere computed by taking into account 3 major sources of secondaryradiation (neutron and photon) – the cyclotron, energy degraderand its collimator. The fluxes of neutrons/photons produced by protonswere computed using Monte Carlo code MCNPXTM 2.5.0. Energyand angular distributions were computed for various targets and protonbeam energies. Different physical models of high-energy proton interactionswere studied as well. The annual charge at the cyclotron exit wasbased on the “patient model” (distribution of treatment type) establishedfor a similar therapy center in Essen (Germany). Calculated datawere used as an approximation of the radiation field of the most significantsources of radiation (graphite degrader, tantalum collimator). Fluence-to-doseconversion factors from ICRP-74 were used for the annual dose equivalentevaluation. With these results, the shielding analysis in the Therapy-Centerwas performed in the context of the current legislation requirements.

The scaling of the flux and maximum energy of laser-driven sheath-accelerated protons has been investigated as a function of laser pulse energy in the range of 15–380 mJ at intensities of 1016–1018 W/cm2. The pulse duration and target thickness were fixed at 40 fs and 25 nm, respectively, while the laser focal spot size and drive energy were varied. Our results indicate that while the maximum proton energy is dependent on the laser energy and laser spot diameter, the proton flux is primarily related to the laser pulse energy under the conditions studied here. Our measurements show that increasing the laser energy by an order of magnitude results in a more than 500-fold increase in the observed proton flux. Whereas, an order of magnitude increase in the laser intensity generated by decreasing the laser focal spot size, at constant laser energy, gives rise to less than a tenfold increase in observed proton flux.

A series of experiments recently carried out at the Rutherford Appleton Laboratory investigated various aspects of the laser–plasma interaction in the relativistic intensity regime. The propagation of laser pulses through preformed plasmas was studied at intensities exceeding 1019 W/cm2. The transmission of laser energy through long-scale underdense plasmas showed to be inefficient unless a plasma channel is preformed ahead of the main laser pulse. The study of the interaction with overdense plasmas yielded indication of collimated energy transport through the plasma. The production of fast particles during the interaction with solid density targets was also investigated. The measurements revealed the presence of a small-sized directional source of multi-megaelectron volt protons, which was not observed when a plasma was preformed at the back of the solid target. The properties of the source are promising in view of its use in radiographic imaging of dense matter, and preliminary tests were carried out.