Sensitivity to Nuclear Data in the Radioprotection Design of the LIPAC (IFMIF/EVEDA) Beam Dump

Linear IFMIF Prototype Accelerator (LIPAC) is the prototype accelerator of the Engineering Validation and Engineering Design Activities (EVEDA) phase of the International Fusion Materials Irradiation Facility (IFMIF) project. The EVEDA phase is a first IFMIF step devoted to the construction of prototypes of the main units. The deuteron beam of LIPAC (125 mA, 9 MeV) is stopped by a conical copper beam stop, giving rise to neutron and photon sources that must be shielded to comply with dose requirements. A reliable characterization of these secondary sources is a mandatory task.

The built-in-semi-analytical nuclear models used by advanced Monte Carlo transport codes as Monte Carlo N-Particle eXtended (MCNPX) or Particle and Heavy Ion Transport code System (PHITS) have been demonstrated as unreliable for describing deuteron interactions and secondary particle production at these low energies. The use of reliable external nuclear data is consequently necessary in the design of the LIPAC shielding. In particular, the TENDL-2010 library has been compared with recently published experimental data demonstrating its reliability for deuteron interaction on copper at 9 MeV. The Monte Carlo Universidad Nacional de Educación a Distancia (MCUNED) code has been developed to make use of external nuclear data, and its use with the TENDL-2010 library has proven very satisfactory for LIPAC radioprotection analysis.

The impact on radioprotection tasks in LIPAC when the unreliable nuclear models mentioned above are used is discussed.