1. Novel Variable-energy Accelerator for Particle Beam Therapy
Particle beam therapy is a form of radiation treatment for cancer that works by irradiating a tumor with an ion beam generated by an accelerator at an energy determined by the tumor’s shape and its depth below the skin. Hitachi is currently developing a new VEMIC accelerator that can provide precise high-dose irradiation while also featuring small size and low cost that make it suitable for installation at hospitals.
Past practice has been to use either synchrotron or cyclotron accelerators. The former provide high beam energy and easy on/off control while the latter can be made smaller by the use of superconducting electromagnets.
Combining the advantages of these previously used accelerators, a VEMIC accelerator uses the magnetic field produced by a superconducting electromagnet to accelerate the beam in an eccentric trajectory. A beam at the desired energy is then extracted using a high-frequency kicker by locating the extraction channel on the outer edge of a narrow region through which beams of all energies pass.
The principle of acceleration has already been demonstrated under ideal electromagnetic field conditions and further work toward commercialization will proceed on the basis of hardware prototype testing.