Double-beam facility

The design of a new triple ion beam facility for fusion technology application and studies are in progress at Laboratorio Nacional de Fusion, CIEMAT, Madrid, Spain. The first phase of this facility consists in a double beam linear accelerator system of light ions (H+, D+ up to 12 MeV and He++ up to 15 MeV), impinging in targets relevant for fusion studies, mostly made of Lithium compounds. A large number of neutrons will be produced. One of the facility configurations analyzed is shown, whith the accelerator system oriented vertically.

Advanced nuclear analysis is required for the design of this kind of facilities to evaluate the radiation fields for radioprotection purposes. Noneteless, it presents challendes. On the one hand, the evaluation of the neutron production of the target, the most relevant radiation source, is not straightforward. This is due to the unavailability of a reliable nuclear data libraries for the range of energies of interest. Thus a combination an appropriate selection of a nuclear data and models verified against experimental data (EXFOR) is necessary. On the other hand, intense variance reduction techniques are required for the Monte Carlo transport calculations. In this particular case two techniques have been needed: i) enhacement of the secondary particle production (a key feature of code MCUNED) and ii) the global variance reduction techniques (GVR-UNED) to obtain detailed 3D weight windows maps.

The work performed by TECF3IR is focused on the design of the radiological shields required for a safe operation of the facility. Dose maps to define the radiological zones of the facility have been produced. An example is shown.