DIAGNOSTICS FOR HIGH POWER ION BEAMS WITH COHERENT OPTIC FIBER FOR IFMIF-EVEDA INJECTOR

Optical diagnostics based on the excitation of residual gas molecules are routinely used for high intensity beam characterization. Beam intensity, beam position and profile are measured by means of a digital camera. In addition species fraction and profile of each beam are measured using a Doppler shift method. As part of IFMIF-EVEDA project, CEA is in charge of the design and realization of the 140 mA-100 keV cw deuteron source and low energy beam transport line. In the beam line, (D,d) reaction will occur and high neutron flux will be emitted when deuteron beam interacts with surfaces. Moreover gamma ray and activation will also occur. In order to protect diagnostics, coherent optic fibers could be used to transport the beam image outside the irradiated zone. A comparative study of two coherent fibers will be presented (FUJIKURA & SCHOTT), along with the characterization in magnification and transmission of a 610 mm long fiber and its associated optics. To estimate the capability of such fibers to transport beam image, a dedicated experiment has been performed with proton beam produced by the SILHI source. The beam profile has been compared with and without the optic fiber.