Development of a detector for a two-dimensional type beam profile monitor with the use of high intensity beams

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A tow-dimensional type beam profile monitor was developed, and beam profiles were successfully measured without destruction to beams. The beam for these tests were used with injection beams for NIRS HIMAC, of which energy of 6MeV/u, pulse duration of five to eight hundreds micro second, and ion species of carbon, oxygen, and neon with fully stripped. The beam intensity was an order of 10 to the eleventh par pulse. The target was a nitrogen gas jet sheet, of which thickness of 2 or 5mm, width of 60mm (flattened), and density of le-3 Pa. The action of collision between beam and nitrogen sheet, visible light emission of which wave length of almost 400nm is occurred, and which is detected by below detector. Above beam conditions was corresponding to one-tenth in the case of the beam action with any high intensity accelerator of GeV class. The detector was employed an image intensifier (II) and high gain video camera consists of pickup tube (HARP). Beam profiles were confirmed measuring with several ten pulses averaging. This results shows that with high intensity beams (design intensity: 4e13 proton par bunch) such as J-PARC MR, within a time of several bunch, beam profile will be able to detect.In equipment developments, with gamma ray exposure as total dose was 1 to 5MGy, II' s radiation weal points were examined, and the these materials were changed to radiation hardness materials. Avoiding to an emission of light by nitrogen in atmosphere, detection optics with low loss was set in a vacuum chamber. Light transportation from II to HARP camera was done using a radiation hardness type bundled image fibers. And II was operated by remote high voltage transfer.