Influence of linear nozzle structure on impulse coupling coefficient of laser thruster

The nozzle is one of the most important parts of a laser thruster. It can be designed with the focusing system together. It can also be designed independently without considering the focusing system. For the latter case, an ignition mode was set up with an auxiliary focusing system. By changing the parameters of the nozzle, the relationship between the impulse coupling coefficient and two dimensionless parameters, the ratio of the head diameter to the exit diameter of the nozzle and the ratio of the nozzle length to the exit diameter of the nozzle, was obtained. The reasons why the parameters of nozzle structure affect the impulse coupling coefficient were explained. The results show that the propulsion performance of the rotary trapezium nozzle is better than that of the column nozzle or