RESIDUAL GAS FLUORESCENCE FOR PROFILE MEASUREMENTS AT THE GSI UNILAC

The high beam currents, delivered at the LINAC at GSI (UNILAC) can destroy intercepting diagnostics within one macro pulse. As an alternative for a nondestructive profile measurement the methode for residual-gas-fluorescence is investigated. The fluorescence light emitted by the 2 N molecules of the residual gas at the blue wavelength range can be monitored with a modern CCD camera. The images are transferred via digital bus and after analysis of the images with a modern software the profiles are generated. Due to the short beam pulses the light intensities emitted by the residual gas are low and require a high amplification which is realized with an image intensifier with double MCP, connected with a fiber taper to the CCD-chip. The design and measurements are discussed.