Investigation on momentum coupling coefficient for a parabolic shell

Momentum coupling coefficients of TEA CO2 laser pulses for a parabolic aluminum shell were investigated. Momentum coupling coefficients were measured with a pendulum in a chamber, the energy of the incident laser pulse was varied from 8.3J to 50.9J, and the gas pressure in the chamber was changed from 100 kPa to 20 kPa in our experiments. Experimental data were analyzed thoroughly. It was found that the coupling coefficients under the air pressure of 100kPa decreased very slowly from 242 N/MW to 170 N/MW for the incident energy from 50.9J to 15.1J but decreased sharply for the energy between 15.1 J to 13.8 J. And it was different for the air pressure below 100 kPa. Indoor free flight of our parabolic shell was also analyzed, coupling coefficients and some other parameters were deduced from the experimental data.