Real-time measurement and characterization of laser-driven proton beams have become crucial with the advent of high-repetition-rate laser acceleration. Common passive diagnostics such as radiochromic film (RCF) are not suitable for real-time operation due to time-consuming post-processing; therefore, a novel approach is needed. Various scintillator-based detectors have recently gained interest as real-time substitutes to RCF—thanks to their fast response for a wide range of dose deposition rates. This work introduces a compact, scalable, and cost-effective scintillator-based device for proton beam measurements in real-time suitable for the laser–plasma environment. An advanced signal processing technique was implemented based on detailed Monte Carlo simulations, enabling an accurate unfolding of the proton energy and the depth–dose deposition curve. The quenching effect was accounted for based on Birks’ law with the help of the Monte Carlo simulations. The detector was tested in a proof-of-principle experiment at a conventional cyclotron accelerating protons up to 35 MeV of energy. The signal comparison with a standard RCF stack was also performed during the test of the device, showing an excellent agreement between the two diagnostics. Such devices would be suitable for both conventional and laser-driven proton beam characterization.

Objective. This study aims to perform a comprehensive microdosimetric characterization of a clinical helium ion beam at the Heidelberg ion-beam Therapy center, assessing radiation quality along a spread-out Bragg peak (SOBP) and providing experimental data to support the biological effectiveness of helium ions in clinical applications. Approach. Microdosimetric spectra were measured at several water depths within the SOBP using two solid-state detectors: a silicon and a synthetic single-crystal diamond detector. Microdosimetric quantities, including dose-mean lineal energy ( y D ) and frequency-mean lineal energy ( y F ), were derived. Monte Carlo simulations with the Geant4 toolkit replicated the experimental setup to validate the measured quantities. The modified microdosimetric kinetic model was also applied to estimate the relative biological effectiveness at 10% survival (RBE₁₀). SAOS-2 and U2OS clonogenic assays were performed under identical irradiation conditions at the same facility to benchmark the RBE predictions. Main results. The experimental results demonstrated a progressive increase in y D values along the beam path, peaking at the distal edge of the SOBP, consistent with the simulated dose-averaged linear energy transfer distribution. The RBE₁₀ values estimated by the two solid-state detectors showed good agreement with the experimental data from clonogenic assays, within the associated uncertainties. Significance. These findings underscore the utility of advanced solid-state detectors for helium beam characterization and highlight the importance of microdosimetry in improving radiobiological modeling. The results provide further evidence supporting the clinical potential of helium ion therapy, particularly for tumors requiring high precision and maximal healthy tissue sparing.

Radiotherapy (RT) treatments at ultra-high doses (UHDR, >40 Gy/s) can reduce the toxicity induced on healthy tissues while achieving therapeutic goals (in terms of tumor control probability, TCP) that are comparable to those typically attained in conventional dose-rate (CONV) treatments. This is already demonstrated by a large number of in vitro and in vivo studies conducted over the past ten years. Thus, this technique, called FLASH-RT, holds great promise for enhancing RT's effectiveness. Ultra-fast treatments would significantly enhance patient comfort, reduce treatment duration, expand the capacity to treat more patients in clinics, and concurrently decrease the toxicity of the treatment by widening the therapeutic window. However, implementing reliable and accurate dosimetric procedures and developing new absolute and relative dosimetric detectors that can operate properly under these novel and extreme irradiation conditions are necessary for integrating FLASH-RT into clinical practice. In this work, a device based on Silicon Carbide (SiC) technology was tested for the first time with UHDR (from 150 Gy/s to 230 Gy/s) 62 MeV proton beams. A previously tested and successfully calibrated dosimetric chain was used for the SiC characterisation, which was conducted at the INFN-LNS (Istituto Nazionale di Fisica Nucleare-Laboratori Nazionali del Sud, Catania). A preliminary dosimetric characterisation of the SiC device was carried out in terms of dose linearity as the dose rate varied. The detector sensitivity was also evaluated.

Hydrogenated amorphous silicon (a-Si:H) devices on flexible substrates are currently being studied for application in dosimetry and beam flux measurements. The necessity of in vivo dosimetry requires thin devices with maximal transparency and flexibility. For this reason, a thin (<10 µm) a-Si:H device deposited on a thin polyimide sheet is a very valid option for this application. Furthermore, a-Si:H is a material that has an intrinsically high radiation hardness. In order to develop these devices, the HASPIDE (Hydrogenated Amorphous Silicon Pixel Detectors) collaboration has implemented two different device configurations: n-i-p type diodes and charge-selective contact devices.Charge-selective contact-based devices have been studied for solar cell applications and, recently, the above-mentioned collaboration has tested these devices for X-ray dose measurements. In this paper, the HASPIDE collaboration has studied the X-ray and proton response of charge-selective contact devices deposited on Polyimide. The linearity of the photocurrent response to X-ray versus dose-rate has been assessed at various bias voltages. The sensitivity to protons has also been studied at various bias voltages and the wide range linearity has been tested for fluxes in the range from 8.3 × 10⁷ to 2.49 × 10¹⁰ p/(cm² s).