Shielding activation of petawatt laser facilities in Romania: a FLUKA preliminary evaluation.

The FLUKA 2011.2c code was used to evaluate the activity induced in the irradiation chamber walls by secondary charged particles emitted during the interaction of 1 petawatt laser beam with the targets. The results have shown that, even in the most conservative approaches, i.e. 300 and 100 MeV secondary electrons and protons, respectively, the maximum equivalent dose rate, at 1 cm in front of the chamber wall, 1 min after the end of irradiation, was of ∼23 nSv h(-1). Three minutes later, it falls at ∼60 pSv h(-1), negligible with respect to the environmental radiation background of 90-110 nSv h(-1), as reported for Romania.