Effiecient Oxygen-Iodine Chemical Laser Operated by Supersonic Flow

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There has been much interest in the excitation of atomic iodine via the I^2P_<1/2>-I^2P_<3/2> transition in the presence of singlet oxygen (O_2 (^1DELTA)) for chemical oxygen iodine laser (COIL). Generally, the transition in the iodine atoms is pumped by resonant energy transfer from O_2 (^1DELTA), which is produced chemically via the reaction of H_2O_2 in alkali solution with chlorine.The complicated flow field of a SCOIL is simulated by solving the three-dimensional Navier-Stokes equations and effects of mixing/reacting zone structure on the resulting gain region are studied. A chemical kinetic model encompassing 21 chemical reactions is used to determine the chemical composition of gas mixture. The numerical result shows that the cross section of the iodine jet is stretched significantly due to the strong shear force and a pair of contrarotating vortices are formed behind the curved jet. The vortices greatly enhances the mixing and the simultaneous chemical reaction. This result clearly demonstrates the importance of contrarotating vortices behind the iodine jet upon the laser performance.Excitation of iodine atoms, i. e., the transition I^2P_<1/2>-I^2P_<3/2>, effectively occurs, when discharged iodine is mixed with a discharged oxygen flow containing singlet oxygen, O_2 (^1DELTA). We demonstrate that microwave discharge of molecular iodine is useful for the formation of atomic iodine and that the resultant atom is excited by O_2 (^1DELTA) in a two discharge-flow system.