Study of a fast kicker magnet for beam scanning in VHEE therapy

Over the past two decades, very high-energy electron (VHEE) beams ranging from 50 to 250 MeV have been explored as a potential technology for treating deep-seated tumors. FLASH radiation therapy (FLASH-RT) delivers ultra-high dose rates (UHDR) within a few milliseconds, suggests the possibility of enhanced cancer cell lethality while reducing damage to normal tissues. Combining VHEE with FLASH-RT shows potential in cancer treatment. Pencil beam scanning (PBS) is an important technique in VHEE radiotherapy. However, the ultra-short treatment times required by FLASH-RT (0.1–1 second) imply that the scanning speed must be very high, necessitating linear accelerators (LINACs) with a repetition rate significantly higher than 1 kHz, which is challenging to achieve. A fast kicker magnet, consisting of a one-turn coil and a pulsed power supply, can generate a magnetic field with rapid rise and fall times. A LINAC can produce an electron beam with a variable bunch train of 0.1-1 μs. By deflecting the bunch train using a fast kicker magnet, it is possible to generate a line scan that approximates the functionality of pencil beam scanning.