Preliminary study on temperature distribution and pyroelectric current of LiNbO₃ heated by nanosecond pulse laser

Abstract In order to reduce the volume of compact neutron generators, a lot of investigations are carried out on generating high voltages by heating pyroelectric crystals with external heating. Laser irradiation is an effective non-contact heating method. Different laser parameters determine the crystal's temperature distribution, impacting the accelerating electric field. A preliminary study on the temperature distribution and pyroelectric current response of LiNbO 3 heated by nanosecond pulse laser is presented, including both direct heating and heating with Cu and Ti disks adhered to the crystal. A two-dimensional transient heat transfer and circuit model is constructed in COMSOL. To validate the simulation model of temperature field distribution, FLIR thermal camera is utilized to measure the temperature in laser spot center experimentally. The experimental results coincide with simulations, which prove that the simulation model can predict temperature field distribution of the pyroelectric crystal effectively. This study can benefit the optimization of laser parameters for modulating high-quality deuterium ion acceleration fields.