Development of compact picosecond pulse radiolysis system

A pulse radiolysis technique is known as a powerful method to study the primary processes in radiation chemistry. However, a large-sized accelerator and a huge cost should be required for the construction and operation of pulse radiolysis system. Very recently, the new compact picosecond pulse radiolysis system composed of the small size accelerator and laser system has been developed at RISE, Waseda University. To evaluate the performance of the system, the absorption measurement of hydrated electrons was carried out as a preliminary experiment. As a result, the time resolution was estimated to be approximately 26 ps. It is analytically calculated to be approximately 30 ps (FWHM) with the convolution among the beam size, the bunch length of electron beam, the laser spot size, and the laser pulse length. The experimental value is in good agreement with the calculated one. The system has been developed to get better S/N ratio and will be applied for the study of primary processes in radiation chemistry of polymer system.