• F.B. Bouly, J.-L. Biarrotte, S. Bousson, C. Commeaux, C. Joly, J. Lesrel
  IPN, Orsay
• A. Bosotti, P.M. Michelato, R. Paparella, P. Pierini, D. Sertore
  INFN/LASA, Segrate (MI)

Accelerator Driven systems (ADS) are being considered for their potential use in the transmutation of nuclear waste. Because of the induced thermal stress to the subcritical core, the high-power proton LINAC will have to fulfill stringent reliability requirements and to minimize the number of unwanted beam trips per operation cycle. It is forseen to build an ADS demonstrator (MYRRHA) in Mol (Belgium). Such a device will be piloted by a 600 MeV / 4mA superconducting linac. IPN Orsay and INFN Milano are in charge of the realisation and tests of a prototypical cryomodule for the high energy section of the accelerator, equipped with a 5-cell superconducting cavity. Developed at INFN, this RF cryogenic accelerating device is tested for the first time at IPN. We will describe the status of the R&D activities on this device. The first low power tests of the 5-cell superconducting cavity in its prototypical cryomodule will be reviewed. Those tests aim to evaluate the cavity performances after installation in the module (16MV/m in vertical test) but also to measure the tuning systems behaviors in view of reliability considerations for 'fast fault-recovery scenarios'.

• E. Rampnoux, S. Berthelot, J.-L. Biarrotte, P. Blache, C. Commeaux, F. Doizon, D. Grolet, P. Szott, J.-F. Yaniche
  IPN, Orsay

MYRRHA project consists of the construction of an experimental facility in order to demonstrate the technical feasibility of Transmutation of high-level nuclear waste in an Accelerator Driver System. Thus the sub-critical core must be fed by a neutron beam resulting from a great quality spallation of a high-intensity proton beam on a target. Because of the induced thermal stress to the subcritical core, the high-power proton LINAC must have a great reliability to minimize the number of unwanted beam trips. The MYRRHA ADS demonstrator requires a high power proton superconductive linac (600MeV/4mA) operating in CW mode with the characteristic that each components of it must have the greatest reliability. In this framework IPN Orsay is in charge of the development of a power coupler for the 5-cells superconducting cavities present in the high energy section of the linac. We will describe all the stages about power coupler developments, from the conception to the conditioning. We will present the design, the commissioning of the test stand and the results of the couplers conditioning. A last part will show the reliability tests carried out with a 50 kW RF power during a long time.