Bulletin of the American Physical Society
2006 59th Annual Gaseous Electronics Conference
Tuesday–Friday, October 10–13, 2006; Columbus, Ohio
Session ET2: Oxygen-Iodine Lasers |
Hide Abstracts |
Chair: Yurii Utkin, Ohio State University Room: Holiday Inn Salon B |
Tuesday, October 10, 2006 4:00PM - 4:15PM |
ET2.00001: Electric discharge oxygen-iodine laser: three decades from the idea to the laser development. Andrey Ionin The overview of experimental research aimed at the research and development of an electric discharge oxygen-iodine laser (DOIL) since the first negative attempt of launching a DOIL in the 1970's is presented. The problem is tightly connected with the development of singlet delta oxygen (SDO) electric generator, which could substitute in future for SDO chemical one used for a high-power COIL resulting in the development of a high-power DOIL. The main experimental and theoretical efforts focused onto studying and understanding of physical processes, which could help in or prevent from achieving and exceeding the threshold SDO yield at partial oxygen pressure adequate for modern oxygen-iodine laser technology, are discussed. Quite recently obtained results on gain and output characteristics of DOIL, and some projects aimed at the development of high-power DOIL are discussed. [Preview Abstract] |
Tuesday, October 10, 2006 4:15PM - 4:30PM |
ET2.00002: Singlet delta oxygen production in low-temperature plasma. Andrey Ionin The overview of experimental research in the field of physics and engineering of singlet delta oxygen (SDO) production in low-temperature plasma of various electric discharges is presented. The main attention is paid to the SDO production with SDO yield adequate for the development of an electric discharge oxygen-iodine laser (DOIL). Experimental procedures of SDO production in self-sustained and non-self-sustained discharges, and analysis of different plasma-chemical processes occurring in oxygen low-temperature plasma which brings limitation to the maximum SDO yield and to the life-time of the SDO in an electric discharge and its afterglow are discussed. [Preview Abstract] |
Tuesday, October 10, 2006 4:30PM - 4:45PM |
ET2.00003: Pulse discharge production of iodine atoms for COIL Anatoly Napartovich, Igor Kochetov, Nikolay Vagin, Nikolay Yuryshev The pulse mode of operation of the chemical oxygen iodine laser (COIL) is attractive for a large body of new applications. Pulsed electric discharge is most effective to turn COIL operation into pulse mode by instant production of iodine atoms. Numerical model is developed for simulations of the pulsed COIL initiated by electric discharge. The model comprises a system of kinetic equations for neutral and charged species, electric circuit equation, gas thermal balance equation, and the photon balance equation. Reaction rate coefficients for processes involving electrons are found by solving the electron Boltzmann equation, which is re-calculated in a course of computations when plasma parameters changed. The processes accounted for in the Boltzmann equation include excitation and ionization of atoms and molecules, electron-ion recombination, electron-electron collisions, second-kind collisions, and stepwise excitation of molecules. The last processes are particularly important because of a high singlet oxygen concentration in gas flow from the singlet oxygen chemical generator. Results of numerical simulations for conditions of the experiments are compared with results of measurements. Data will be presented for various conditions: gas pressure and composition, electrode geometry, electric circuit parameters. [Preview Abstract] |
Tuesday, October 10, 2006 4:45PM - 5:00PM |
ET2.00004: O$_{2}(^{1}\Delta )$ Production and Oxygen-Iodine Kinetics in Flowing Afterglows for Electrically Excited Chemical-Oxygen-Iodine Lasers Ramesh Arakoni, Natalie Y. Babaeva, Mark J. Kushner Chemical oxygen-iodine lasers (COILs) achieve oscillation on the $^{2}$P$_{1/2}\to ^{2}$P$_{3/2}$ transition of atomic iodine at 1.315 $\mu $m by a series of excitation transfers from O$_{2}(^{1}\Delta )$. In electrically excited COILs, (eCOILs) the O$_{2}(^{1}\Delta )$ is produced in a flowing plasma, typically He/O$_{2}$, at a few to tens of Torr. eCOILs additionally differ from conventional systems in the large amount of O atoms produced due to electron impact dissociation. O atoms are advantageous in that they react with and dissociate I$_{2}$, but O atoms also quench I($^{2}$P$_{1/2})$. To some degree, the O atom density in the afterglow can be controlled by injecting NO or NO$_{2}$ which consumes O atoms. This also impacts O$_{3}$ production, particularly at higher pressures where quenching of O$_{2}(^{1}\Delta )$ by O$_{3}$ is problematic. In this paper, results from computational investigations using plug-flow and 2-dimensional plasma hydrodynamics models will be discussed for scaling laws in eCOIL systems for O$_{2}(^{1}\Delta )$ production. We will discuss O-atom management with NO/NO$_{2}$ additives and I($^{2}$P$_{1/2})$ production with I$_{2}$ injection. Scaling to higher pressures will be discussed where gas heating and O$_{3}$ quenching of O$_{2}(^{1}\Delta )$ become important. [Preview Abstract] |
Tuesday, October 10, 2006 5:00PM - 5:15PM |
ET2.00005: Gain Measurements in a Non-Self-Sustained Electric Discharge Pumped Oxygen-Iodine Laser Cavity Igor Adamovich, Adam Hicks, Yurii Utkin, Walter Lempert, J. William Rich The paper presents results of singlet delta oxygen (SDO) yield measurements in a high-pressure, non-self-sustained crossed discharge and small signal gain measurement on the iodine atom transition in the M=3 supersonic cavity downstream of the discharge. The results demonstrate operation of a stable and diffuse crossed discharge in O$_{2}$ -- He mixtures at pressures of up to P$_{0}$=120 torr and discharge powers of up to 2.2 kW. The reduced electric field in the sustainer discharge in O$_{2}$-He flows ranges from 6 to 12 Td. Singlet delta oxygen yield in the discharge, up to 5.0-5.7{\%} at the discharge temperatures of 400-420 K, was inferred from the integrated intensity of the (0,0) band of the SDO infrared emission spectra calibrated using a blackbody source. These results suggest that the measured singlet delta oxygen yield would exceed the threshold yield at the flow temperature achieved in the supersonic cavity, T=120 K, by about a factor of three. Gain measurements clearly confirmed this prediction. Preliminary measurements demonstrate gains of up to 0.03{\%}/cm measured in the supersonic cavity at these conditions. [Preview Abstract] |
Tuesday, October 10, 2006 5:15PM - 5:30PM |
ET2.00006: Collisional broadening coefficients of singlet ($a^{1}\Delta _{g})$ oxygen with helium Skip Williams, Jeffrey Gallagher, Glen Perram A novel laser-based technique applicable to metastable species detection is discussed. Off-axis integrated-cavity-output spectroscopy (ICOS) has been applied to the study of singlet ($a^{1}\Delta _{g})$ oxygen. Singlet oxygen was generated in a microwave plasma, and the afterglow passed through an off-axis ICOS measurement system consisting of an 82-cm long, high-finesse optical cavity bounded by two highly reflective mirrors. The mirror reflectivity was determined by performing cavity-ringdown measurements and observing ringdown times of 220-250 $\mu $s in a range from 1494 nm to 1512 nm. A diode laser was current tuned, and light exiting the cavity was focused onto an InGaAs detector. The cavity transmission was recorded as a function of laser frequency. Details of the method will be presented as well as the spectroscopic characterization of selected transitions of the (1,0) band of the $b^{1}\Sigma _{g}^{+ }$- $a^{1}\Delta _{g}$ Noxon system of oxygen (radiative lifetime 160 minutes). Pressure broadening coefficients with helium as the collision partner for selected transitions will also be presented. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700