Radiation protection aspects in the vicinity of TW class laser systems

Abstract

Modern laser systems are able to generate ionizing radiation of significantly high energies by focusing ultra-short intense pulses onto targets. This study is focused on evaluating possible radiological hazards resulting from the fs high repetition rate laser, operating in a high intensity regime. Characteristics of radiation field generated within a typical experiment of electron acceleration are explored both theoretically and experimentally. The electron bunches with the charge of ~ pC, the pulse duration of ~fs, and 100 MeV energy in a single shot regime were chosen as a benchmark. First, the shielding capabilities of the civil structure surrounding the interaction chamber were examined. Second, responses of typical personal dosimeters (film, TLD, and electronic personal dosimeter), designed for usage in continuous fields, were studied in a pulsed radiation field. Measurements were performed at a Ti:Sapphire 25 TW laser system recently installed at PALS Research Centre in Prague. In accordance with the ALARA principle, the adequacy of an existing bulk shielding for the model electron acceleration experiment was verified and working regime was recommended.