Studying of thermal blooming of HEL in the non-flowing beam tube

摘要

Thermal blooming is one of the most important factors, which make the beam diffused and cause the decline of laser intensity on the object. This paper presents a method to reduce thermal blooming of high-energy laser (HEL) in the beam tube and compares two models describing the thermal blooming. Helium has the qualities of low absorption coefficient, high thermal conductivity and low index of refraction, and can be used as the medium through which HEL beam propagates. The condensations of thermal conduction model and acoustic wave model are evaluated respectively. Results show the method is practicable, and two models' applicable ranges are got.