Assessment of HIE-ISOLDE expected layout through
                        FLUKA simulations (using Flair).

                        Leonel Raul Morejon Hernandez
                                   CERN

Abstract:
The ISOLDE facility is among the laboratories leading worldwide the studies and
production of radioactive nuclei. It receives up to 1.4 GeV protons in a beam of
~2 microA, which give rise to a wide variety of isotopes by incidence in various
targets of more than 25 different materials. The HIE-ISOLDE project, aiming for
the widening of accessible energy range this range, is planning to raise of up
to 2 GeV the energy and increase up to 4 times the intensity of the beam, which
will increase the radiation levels. Then, an evaluation of the radiation levels
expected for the current layout, and the optimization of the features for a new
targets\' storage are mandatory. Using FLUKA code (by means of the software
Flair) the projected options for the target\'s storage were implemented in the
geometry of the ISOLDE facility and simulated to estimate the dose levels due to
radiation coming from the experimental facility, as well as that coming from the
decay of the storaged used targ! ets. Since is a rather big facility, the
setting-up of the geometry is rather time consuming, and the simulations need
for optimizations like biasing and use of a source file to generate particles
near the areas of interest with the correct profile. The use of Flair software
made the implementation of the geometry, the handling of the runs and analysis
of the results much faster than expected (without it) allowing to focus on the
optimization and a faster data collection.