Irradiation facility for radiobiology and molecular biophysics studies at the University of Sمo Paulo Pelletron Accelerator laboratory

In this work, we describe the new facility for Radiobiology and Molecular Biophysics studies with charged particle beams, built at the University of São Paulo Pelletron Accelerator Laboratory. It consists of a dedicated beam line, sample holder and dose monitoring system. The beam line is designed in such a way that a 15 mm diameter and 2% uniformity external beam is delivered to the sample. In order to reach these beam features, the beam line is composed of one focusing system with tantalum slits and a Faraday cup, two scattering chambers with 1 mm tantalum collimators and 2 mg/cm2 Au diffusing foils, and one 10 μm thick mylar foil serving as exit window. The sample holder has x, y and z movement with 10 μm precision and the dose monitoring system consists of one Si detector inside each scattering chamber, and one Si detector in air at the sample location. A multiwire position sensitive detector will be soon installed right before the exit window to monitor the beam shape and help in the beam uniformity measurements. cility and tests of the beam uniformity and dose monitoring system are described. The dose tests are performed through the irradiation of LiF TLD-100 crystals and the comparison of their results with the calculated values based on the counting rate on the Si detectors.