Martina Salvadori | Searcharxiv

arXiv2025

Radionuclide Production for Dose Verification in VHEE FLASH Radiotherapy

This study explores the production of radionuclides in a PMMA (Polymethylmethacrylate) phantom irradiated with Very High Energy Electrons (VHEE) beams as a novel method for dose verification. In this work, Monte Carlo simulation studies using the Geant4 toolkit and experimental measurements with a VHEE beam produced by a laser-plasma accelerator were conducted. Specifically, the photonuclear production of 11C, 15O and 13N is examined, with a detailed analysis of their spatial distribution, production yields and decay time

physics.med-ph↗

arXiv2024

Laser Interactions with Gas Jets: EMP Emission and Nozzle Damage

Understanding the physics of electromagnetic pulse emission and nozzle damage is critical for the long-term operation of laser experiments with gas targets, particularly at facilities looking to produce stable sources of radiation at high repetition rate. We present a theoretical model of plasma formation and electrostatic charging when high-power lasers are focused inside gases. The model can be used to estimate the amplitude of gigahertz electromagnetic pulses (EMPs) produced by the laser and the extent of damage to the gas jet nozzle. Looking at a range of laser and target properties relevant to existing high-power laser systems, we find that EMP fields of tens to hundreds of kV/m can be generated several metres from the gas jet. Model predictions are compared with measurements of EMP, plasma formation and nozzle damage from two experiments on the VEGA-3 laser and one experiment on the Vulcan Petawatt laser.

physics.plasm-ph↗