Speaker
Description
Recent interest in ultra-high-dose-rate (UHDR) irradiation and FLASH radiotherapy has stimulated the development of experimental platforms capable of delivering radiation under increasingly extreme temporal conditions. Short-wavelength photon sources are particularly attractive because they combine highly localized energy deposition with pulse structures spanning from nanoseconds to femtoseconds. Such sources provide unique opportunities for exploring radiation action beyond the regimes accessible with conventional irradiation technologies.
Using a compact laser-plasma source operating in the water-window spectral range, we have investigated a broad range of irradiation scenarios including aqueous chemical dosimetry, DNA irradiation in liquid and dry environments, and microbial spore inactivation. By modifying sample geometry and irradiation conditions while maintaining the same source architecture, a wide spectrum of dose-rate regimes and biological endpoints can be addressed. The source provides a versatile laboratory-scale platform for studies of radiation chemistry, radiobiology, and UHDR effects under highly localized irradiation conditions.
To further extend these capabilities, a microfluidic irradiation cell is currently being developed for controlled exposure of liquid samples and biological systems. The approach enables precise sample handling, continuous replenishment of irradiated volumes, reduced sample consumption, and improved compatibility with strongly absorbed soft X-ray radiation. In addition, microfluidic platforms offer a promising route toward time-resolved studies that connect the physical, chemical, and biological stages of radiation action.
Beyond laser-plasma sources, free-electron lasers and related short-wavelength facilities provide access to femtosecond pulse durations and correspondingly extreme instantaneous dose rates. These instruments enable investigation of irradiation regimes where the temporal structure of the radiation approaches the timescales of primary ionization and early physicochemical processes. Combining compact laser-plasma sources, advanced microfluidic irradiation technologies, and large-scale FEL facilities therefore creates a complementary experimental toolbox spanning many orders of magnitude in pulse duration and dose rate.
This framework opens new opportunities for systematic studies of UHDR and FLASH-relevant radiation effects and for understanding how temporal dose delivery influences radiation action from the earliest physicochemical events to complex biological responses.
