Gas-Solid Singlet Delta Oxygen Generator for the Chemical Iodine Laser

摘要

The chemical oxygen-iodine laser (COIL) involves the production of electronically excited singlet delta oxygen at 1.27 microns by passing chlorine gas through aqueous, basic hydrogen peroxide (H2O2/OH). Unfortunately, the process of nonradiative relaxation used in COIL results in the creation of undesired heat and not the desired light emission. Several patented developments have addressed this need to rapidly extract the excited oxygen from its quenching, aqueous environment and efficiently mix it with iodine for subsequent lasing at 1.3 microns. One response to the problems with aqueous COIL chemistry was AFRL's development of the all gas-phase iodine laser (AGIL). The AGIL produces excited nitrogen chloride from chlorine atoms and gaseous hydrogen azide. However, AGIL is compromised by the explosion hazards of its HN3 chemistry. In an effort to improve the safety and reduce the complexity of COIL and AGIL, chemists in AFRL's Propulsion Directorate at Edwards AFB investigated alternative means of preparing singlet delta oxygen from safe starting materials while avoiding liquid-phase quenching problems. Solid-solid, solid pyrolysis, and gas-solid reactions were investigated. Their breakthrough came when singlet delta oxygen was produced with solid alkali metal/alkaline earth peroxides and gaseous hydrogen/deuterium halides. The production of singlet delta oxygen was verified by observing its emission at 1.27 microns and comparing the emission wavelength and band contour with well-known singlet delta oxygen sources. The nonhazardous, commercially available reagents react nonviolently and the products are oxygen, water, and benign alkali metal or alkaline earth-halide salts. Further development of this concept could provide an improved singlet delta oxygen generator that utilizes the already available COIL technology for iodine atom production, oxygen-iodine atom mixing, and 1.3 micron laser light extraction. (4 refs.).