SPIRAL2-Cryomodule A

The 12 cryomodules A will be separated by diagnostics boxes à diagnosis along the superconducting LINAC line.

PRESENTATION OF THE PROJECT

The high-energy part of the linear accelerator of SPIRAL2 includes two sets of superconducting cavities at 88 MHz, of l/4 type, working at 4 K (temperature of liquid Helium boiling at atmospheric pressure). Each of the geometry is optimized to accelerate ions with relative velocities (over light speed) equal to b=v/c=0.07 and 0.12, respectively.

With this distribution it is possible to adapt the acceleration efficiency of the cavities to the increasing speed of ions along the accelerator line. The first family of cryomodules of type "A", is composed of 12 cryomodules including each a superconducting cavity optimized for b=0.07. This series of cryomodules can accelerate the ion beam coming from the injector (cf sub-project injector/SPIRAL2) to deliver it to the second family of cryomodules of type "B" each including 2 cavities optimized for b=0.12.

The project "Cryomodules A" follows the studies done during the detailed preparatory project "APD" during which a prototype cavity was realized and tested successfully. The mechanical study of the cryomodule was carried out simultaneously with the realization and tests of this prototype.

CONTRIBUTION DU DAPNIA

DAPNIA was in charge with the study, start and check of the making of the components of these cryomodules A and also with their assembly. The preparation of the cavities as well as the assembly has required an experimental room of quality better than ISO5 (class 100).

The responsibility of DAPNIA has included the realization of a cryogenic test bench in RF power in the SupraTech HF/Cryo area of the Saclay site. All the cavities will be submitted to the validation tests in the vertical cryostat, before the mounting in the cryomodule. This will be followed by a second series of tests done on the cryomodules in their final configuration before the delivery to GANIL. The DAPNIA department will give expertise help to the GANIL when the cryomodules are integrated in the site, and the DAPNIA teams will participate to the commissioning of the accelerator.

COLLABORATIONS

Amongst all the collaborators of the SPIRAL2 project, the main partners for the cryomodules are the GANIL teams for SPIRAL2, IPN-Orsay, and the LPSC laboratory (Grenoble).