Development of a Silicon Detector Monitor for the HIE-ISOLDE Superconducting Upgrade of the REX-ISOLDE Linac

A silicon detector monitor has been developed and tested at REX-ISOLDE in the framework of the R&D program for the HIE-ISOLDE superconducting (SC) linac upgrade. In the future setup the monitor is intended to be located downstream of the cryogenic SC modules, for beam energy and timing measurements and for the SC cavities phase scanning. In this very first test a passivated ion implanted silicon detector, suited for charge particle spectroscopy, was mounted inside a REX diagnostic box, downstream of the 9-gap resonator. A strongly attenuated stable ion beam with a mass-to-charge state (A/Q) of 4, mainly composed of 12C3+, 16O4+ and 20Ne5+, was used for the tests. The energy measurements carried out allowed for beam spectroscopy and ion identification with an energy resolution of ~ 3 % FWHM. The energy identification of the stable beam was suited for a rapid scan of the cavity; a procedure which could be demonstrated for the third 7-gap cavity. The time structure of the beam, characterized by a 9.87 ns period, could be reconstructed with the time resolution of ~200 ps.