The Accelerators, Cryogeny and Magnetism Division

Presentation:

During the negotiations on the location of ITER site, international partners measured the interest to set up a complete program on fusion energy. In parallel to ITER, the “Broader Approach” was decided, covering three large research projects (IFMIF-EVEDA, superconducting tokamak JT60-SA and IFERC computing center).

IFMIF(International Fusion Materials Irradiation Facility):

IFMIF:

the future IFMIF facility is an irradiation tool, aiming at qualifying advanced materials resistant to extreme conditions, specific to fusion reactors that will succeed to ITER. It will be constituted of two deuteron accelerators, delivering in parallel and continuously their beams of a total power of 10 MW on a liquid lithium source, in order to generate the intense flux of neutrons (10¹⁷ neutrons/s) at 14 MeV.

IFMIF-EVEDA:

The implementation of this ambitious project requires as a first step the construction of prototypes of the main units. IFMIF-EVEDA (Engineering Validation Engineering Design Activities) includes three themes: prototype accelerator, lithium target and test cells. The activities, planned over a period of six years, are shared between the Team Project located at Rokkasho (Japan) and the System Groups distributed between Europe and Japan.

Objectives:

The objectives of the EVEDA phase are the following:

• Studies of integration and engineering, with the supply of a detailed file including the plans of construction, the specifications for equipments on the critical path, the generic safety analysis, etc. 
• The validation of the concepts, by the construction of three prototypes: an accelerator, a 1:3 scale lithium target , the test cells of materials.

  At the European level, the Accelerator activities are led by 3 countries: France (DSM/DAPNIA-Saclay), Spain (CIEMAT-Madrid), Italy (INFN-Legnaro).

The coordination of the studies and the realization of the prototype accelerator are entrusted to a European team (Accelerator System Group) located at CEA / Saclay

Context:

The qualification of materials capable of resisting to the intense and lengthy irradiation by 14 MeV neutrons is an essential step for the reactor (DEMO) which will succeed ITER and will have to test the efficiency of the conversion of energy into electricity. While the damage caused by irradiation will be of the order of 30 dpa (movements by atom) a year for DEMO, it will only be of 3 dpa on ITER life duration (10 dpa means that each atom in the material is displaced on average 10 times from its position in the crystalline network, provoking structural defects).
IFMIF, which aims at very high levels of irradiation (20 to 50 dpa per year), will be a unique irradiation facility in the world. The intense flux of neutrons of 14 MeV is created by break-up of high intensity ion beams (deuterons on lithium target) producted by high poweraccelerators.

 Localisation:

The components of the accelerator will be conceived, realized and partially tested in Europe. The final assembly of the accelerator, then its increase in power with beam (commissioning) will be achieved in buildings and infrastructures supplied by Japan on Rokkasho site.

Technical means:

The construction of such an accelerator (IFMIF: 40 MeV, 2 x 125 mA) deals with the problem of high power accelerators. It requires the development of the following elements:

• a high intensity ion source, delivering a beam of deutons of 140 mA to 100 keV;
• a RFQ (Radio Frequency Quadripole) cavity to put « in packages » and to accelerate the ions until a 5 MeV energy;
• an adaptation section;
• elements of linear accelerator to reach the final energy (around 10 MeV for EVEDA phase and 40 MeV for IFMIF);
• a line of transportation up to the beam stop of 1,2 MW for EVEDA phase and up to the liquid lithium target of 10 MW for IFMIF.

Besides the control command and of safety/radioprotection aspects appropriate for this accelerator, an instrumentation of specific beam (non interceptive diagnostics) is to be conceived and to be implemented.

 Contacts:

Accelerator System Group Responsible:      Alban MOSNIER

System Engineering Responsible:      Pierre-Yves BEAUVAIS

Project Control and Quality Insurance:    Philippe GASTINEL