Abstract
Abstract
Ultra-high-dose-rate (UHDR) radiotherapy is expanding across modalities, but its mechanisms and optimal irradiation conditions remain unclear. This study aimed to establish a UHDR electron irradiation field using KURNS-LINAC to support research to elucidate the underlying mechanisms. The irradiation field was characterized through a comprehensive dosimetric evaluation using graphite blocks, radiochromic films, glass dosimeters, and Monte Carlo simulations. Single-shot irradiation experiments were conducted using 8 MeV electrons, and the dose rate at different distances from the beam port was evaluated. The results showed a monotonic decrease in the dose rate with increasing distance. The maximum pulse dose rate reached 8.07×10⁷ Gy/s, satisfying the conditions required for the FLASH effect. The two-dimensional dose distributions revealed beam broadening and a gradual reduction in the steep dose gradient with increasing distance due to air scattering. These findings demonstrate that the KURNS-LINAC can provide a flexible platform for UHDR irradiation.