An optimization study of the LUCE method

A new scheme of the charge exchange injection LUCE is reported for the proton storage ring of the next-generation 5 MW-class neutron sources. In this scheme, periodic magnetic fields (undulators) and laser light (a powerful laser) are used and can ionize the hydrogen beam efficiently in stead of stripping foils. This injection device is composed of a neutralizer and an ionizer, which are placed along a straight section of the ring. The neutralizer strips the electron of H- beam into H0 one with a tapered undulator. The ionizer is composed of a long undulator and an optical system. including an intense laser and an optical system. The optical system can excite the H0 beam of the ground level to that of n=3 level. The magnetic field of the undulator can ionize the excited H0 beam into H+ one efficiently. By the scheme, the radioactive elements unintentionally produced by the injection can be minimized and the emittance growth of the beam can be very small. Moreover, this system has no effect on the trajectory of the circulating proton beam in the ring under the plane undulator approximation. The undulators and the powerful laser, can be realized with existing technologies. (author)