Dose and residual activity estimations for 30 MeV DAE Medical Cyclotron, Kolkata

Medical Cyclotrons are being used for producing various radio-isotopes for diagnostic and therapeutic purpose. The radio-nuclides having very short half-lives and specific decay characteristics are required generally for this purpose. Moreover, these machines are installed in densely populated area. Radiation protection surveillance is of importance from the day of its inception keeping in mind as low as reasonably achievable radiation exposure for radiation workers as well as general public. The planning for decommission of the machine also to be considered during the design stage. The future perspective of these machines are being considered to extend their applications in research and development in alternate fields such as material science studies due to the possibility of high beam intensity delivery (500 μA or more). The upcoming DAB medical cyclotron (30 MeV proton beam) at Kolkata will cater the need for radiopharmaceuticals of our country and also to provide beam lines for various research and development. The radiation environment around these cyclotron facilities need to be studied very carefully due to high intense proton beams and variety of target materials used in such facilities. An attempt has been made to estimate the dose rate due to prompt secondary neutrons and electromagnetic photons around the target materials like Fe, Cu and Ta of different thicknesses using Monte-Carlo simulation with FLUKA code. Also an estimation of residual induced radioactivity in materials commonly used, such as Concrete, Fe and Al have been carried out