Cellular irradiations with laser-driven carbon ions at ultra-high dose rates.

Carbon is an ion species of significant radiobiological interest, particularly in view of its use in cancer radiotherapy, where its large Relative Biological Efficiency is often exploited to overcome radio resistance. A growing interest in highly pulsed carbon delivery has arisen in the context of the development of the FLASH radiotherapy approach, with recent studies carried out at dose rates of 40 Gy s. Laser acceleration methods, producing ultrashort ion bursts, can now enable the delivery of Gy-level doses of carbon ions at ultra-high dose rates (UHDRs), exceeding 10Gy s.

Development of a portable hypoxia chamber for ultra-high dose rate laser-driven proton radiobiology applications.

Background: There is currently significant interest in assessing the role of oxygen in the radiobiological effects at ultra-high dose rates. Oxygen modulation is postulated to play a role in the enhanced sparing effect observed in FLASH radiotherapy, where particles are delivered at 40-1000 Gy/s. Furthermore, the development of laser-driven accelerators now enables radiobiology experiments in extreme regimes where dose rates can exceed 10 Gy/s, and predicted oxygen depletion effects on cellular response can be tested.

Ultrafast laser-driven microlens to focus and energy-select mega-electron volt protons.

We present a technique for simultaneous focusing and energy selection of high-current, mega-electron volt proton beams with the use of radial, transient electric fields (10(7) to 10(10) volts per meter) triggered on the inner walls of a hollow microcylinder by an intense subpicosecond laser pulse. Because of the transient nature of the focusing fields, the proposed method allows selection of a desired range out of the spectrum of the polyenergetic proton beam. This technique addresses current drawbacks of laser-accelerated proton beams, such as their broad spectrum and divergence at the source.