| Laser-driven (LD) ion accelerators show promise for radiobiological research, particularly in cancer therapy, due to their ability to deliver high-intensity proton beams at ultra-high dose rates (UHDR). Research has shown that the use of dose rates >40 Gy/s in radiotherapy leads to the differential sparing of healthy tissues relative to tumors (termed the FLASH effect) but this phenomenon is not well understood. At the BELLA PW iP2 beamline, a series of both in vitro and in vivo experiments have been conducted with proton bunches with instantaneous dose rates up to 10^8 Gy/s and energies up to 30 MeV have been used to study the FLASH effect. The experiments revealed reduced tissue damage in mouse ears irradiated with 10 MeV LD protons versus conventional x-rays. Advanced beam transport and dosimetry diagnostics, including online integrating current transformers and calibrated radiochromic films, were implemented to enhance the dose rate and accuracy. These capabilities are now enabling further studies on the FLASH effect and support future radiobiological applications at BELLA. This talk will give an overview of the experiments conducted with an emphasis on the beam delivery and dosimetry techniques used in these experiments. |
