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1

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from April 1, 1985 to Sept. 30, 1985 under NASA grant NAS1-441 entitled direct solar pumped iodine laser amplifier. During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator was carried out before the amplifier studies. The amplifier studies are postponed to the extended period following completion of the parametric studies. In addition, the kinetic modeling of a solar pumped iodine laser amplifier, and the experimental work for a solar pumped dye laser amplifier are in progress. This report contains three parts: (1) the radiation characteristics of solar simulator and the parametric characteristics of photodissociation iodine laser continuously pumped by a Vortek solar simulator; (2) kinetic modeling of a solar pumped iodine laser amplifier; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

Han, K. S.

1985-01-01

2

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The improvement on the collection system of the Tarmarack Solar Simulator beam was attemped. The basic study of evaluating the solid state laser materials for the solar pumping and also the work to construct a kinetic model algorithm for the flashlamp pumped iodine lasers were carried out. It was observed that the collector cone worked better than the lens assembly in order to collect the solar simulator beam and to focus it down to a strong power density. The study on the various laser materials and their lasing characteristics shows that the neodymium and chromium co-doped gadolinium scandium gallium garnet (Nr:Cr:GSGG) may be a strong candidate for the high power solar pumped solid state laser crystal. On the other hand the improved kinetic modeling for the flashlamp pumped iodine laser provides a good agreement between the theoretical model and the experimental data on the laser power output, and predicts the output parameters of a solar pumped iodine laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1987-01-01

3

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

Han, Kwang S.; Hwang, In Heon

1990-01-01

4

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from September 1, 1988 to February 28, 1989 under NASA grant NAG-1-441 entitled, Direct Solar-Pumped Iodine Laser Amplifier. During this period, the research effort was concentrated on the solar pumped master oscillator power amplifier (MOPA) system using n-C3F7I. In the experimental work, the amplification measurement was conducted to identify the optimum conditions for amplification of the center's Vortek solar simulator pumped iodine laser amplifier. A modeling effort was also pursued to explain the experimental results in the theoretical work. The amplification measurement of the solar simulator pumped iodine laser amplifier is the first amplification experiment on the continuously pumped amplifier. The small signal amplification of 5 was achieved for the triple pass geometry of the 15 cm long solar simulator pumped amplifier at the n-C3F7I pressure of 20 torr, at the flow velocity of 6 m/sec and at the pumping intensity of 1500 solar constants. The XeCl laser pumped iodine laser oscillator, which was developed in the previous research, was employed as the master oscillator for the amplification measurement. In the theoretical work, the rate equations of the amplifier was established and the small signal amplification was calculated for the solar simulator pumped iodine laser amplifier. The amplification calculated from the kinetic equations with the previously measured rate coefficients reveals very large disagreement with experimental measurement. Moreover, the optimum condition predicted by the kinetic equation is quite discrepant with that measured by experiment. This fact indicates the necessity of study in the measurement of rate coefficients of the continuously pumped iodine laser system.

Han, Kwang S.; Hwang, In Heon; Stock, Larry V.

1989-01-01

5

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

This semiannual progress report covers the period from March 1, 1987 to September 30, 1987 under NASA grant NAG1-441 entitled 'Direct solar-pumped iodine laser amplifier'. During this period Nd:YAG and Nd:Cr:GSGG crystals have been tested for the solar-simulator pumped cw laser, and loss mechanisms of the laser output power in a flashlamp-pumped iodine laser also have been identified theoretically. It was observed that the threshold pump-beam intensities for both Nd:YAG and Nd:Cr:GSGG crystals were about 1000 solar constants, and the cw laser operation of the Nd:Cr:GSGG crystal was more difficult than that of the Nd:YAG crystal under the solar-simulator pumping. The possibility of the Nd:Cr:GSGG laser operation with a fast continuously chopped pumping was also observed. In addition, good agreement between the theoretical calculations and the experimental data on the loss mechanisms of a flashlamp-pumped iodine laser at various fill pressures and various lasants was achieved.

Han, Kwang S.

1987-01-01

6

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

Han, Kwang S.; Kim, K. H.; Stock, L. V.

1986-01-01

7

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

A XeCl laser which was developed earlier for an iodine laser oscillator was modified in order to increase the output pulse energy of XeCl laser so that the iodine laser output energy could be increased. The electrical circuit of the XeCl laser was changed from a simple capacitor discharge circuit of the XeCl laser to a Marx system. Because of this improvement the output energy from the XeCl laser was increased from 60 mj to 80 mj. Subsequently, iodine laser output energy was increased from 100 mj to 3 mj. On the other hand, the energy storage capability and amplification characteristics of the Vortek solar simulator-pumped amplifier was calculated expecting the calculated amplification factor is about 2 and the energy extraction efficiency is 26 percent due to the very low input energy density to the amplifier. As a result of an improved kinetic modeling for the iodine solar simulator pumped power amplifier, it is found that the I-2 along the axis of the tube affects seriously the gain profile. For the gas i-C3F7I at the higher pressures, the gain will decrease due to the I-2 as the pumping intensity increases, and at these higher pressures an increase in flow velocity will increase the gain.

Han, Kwang S.; Hwang, In H.; Stock, Larry V.

1988-01-01

8

Modeling of a solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

The direct conversion in space of solar radiation into laser radiation for power transmission to earth, satellites, or deep space probes shows promise as a reasonably simple technology and may have cost advantage in deployment and greater reliability compared to other methods of space power generation and transmission. The main candidates for solar pumping are the gas dynamic, photochemical, and direct photoexcited lasers. Here consideration is given to the photochemical reaction of alkyliodides which predominantly excite the I(2P1/2) state which then lases at 1.315 microns. The iodine ground state is eventually lost to reconstituting the gas or in the formation of molecular iodine. The rates at which the gas is required to be recycled through the laser system are modest. The side exposure at 100-fold solar concentration of a 100-m long tube with a 1 sq m cross section is estimated to provide 20 kW of continuous laser output. Scaling laws and optimum operating conditions of this system are discussed.

Wilson, J. W.; Lee, J. H.

1980-01-01

9

Direct solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The feasibility of direct solar pumping of an iodine photodissociation laser at lambda = 1.315 microns was investigated. Threshold inversion density and effect of elevated temperature (up to 670 K) on the laser output were measured. These results and the concentration of solar radiation required for the solar pumped iodine laser are discussed.

Lee, J. H.; Shiu, Y. J.; Weaver, W. R.

1980-01-01

10

A 50-kW Module Power Station of Directly Solar-Pumped Iodine Laser  

NASA Technical Reports Server (NTRS)

The conceptual design of a 50 kW Directly Solar-Pumped Iodine Laser (DSPIL) module was developed for a space-based power station which transmits its coherent-beam power to users such as the moon, Martian rovers, or other satellites with large (greater than 25 kW) electric power requirements. Integration of multiple modules would provide an amount of power that exceeds the power of a single module by combining and directing the coherent beams to the user's receiver. The model developed for the DSPIL system conservatively predicts the laser output power (50 kW) that appears much less than the laser output (93 kW) obtained from the gain volume ratio extrapolation of experimental data. The difference in laser outputs may be attributed to reflector configurations adopted in both design and experiment. Even though the photon absorption by multiple reflections in experimental cavity setup was more efficient, the maximum secondary absorption amounts to be only 24.7 percent of the primary. However, the gain volume ratio shows 86 percent more power output than theoretical estimation that is roughly 60 percent more than the contribution by the secondary absorption. Such a difference indicates that the theoretical model adopted in the study underestimates the overall performance of the DSPIL. This fact may tolerate more flexible and radical selection of design parameters than used in this design study. The design achieves an overall specific power of approximately 5 W/kg and total mass of 10 metric tons.

Choi, S. H.; Lee, J. H.; Meador, W. E.; Conway, E. J.

1997-01-01

11

Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March-31 August 1986  

SciTech Connect

In order to evaluate the feasibility of the solar pumped dye laser, the parametric study of a dye laser amplifier pumped by a solar simulator and flashlamp was carried out, and the amplifier gains were measured at various pump beam irradiances on the dye cell. Rhodamine 6G was considered as a candidate for the solar pumped laser because of its good utilization of the solar spectrum and high quantum efficiency. The measurement shows that a solar concentration of 20,000 is required to reach the threshold of the dye. The work to construct a kinetic model algorithm which predicts the output parameter of laser was progressed. The kinetic model was improved such that there is good agreement between the theoretical model and experimental data for the systems defined previously as flashlamp pumped laser oscillator, and the long path length solar pumped laser.

Han, K.S.; Kim, K.H.; Stock, L.V.

1986-11-01

12

Solar pumped laser  

NASA Technical Reports Server (NTRS)

A solar pumped laser is described in which the lasant is a gas that will photodissociate and lase when subjected to sunrays. Sunrays are collected and directed onto the gas lasant to cause it to lase. Applications to laser propulsion and laser power transmission are discussed.

Lee, J. H.; Hohl, F.; Weaver, W. R. (inventors)

1984-01-01

13

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers  

NASA Technical Reports Server (NTRS)

The design and chemical synthesis of new media for solar pumped iodine molecule lasers are explored. In an effort to prepare an iodo fluorocarbon compound absorbing strongly at 300 nm or above, the synthesis of perfluoro allylic iodides was investigated. These compounds furnish especially stable allylic radicals upon photodissociation. The desired red shift is anticipated in the absorption maximum could correlate with increasing radical stability. This expectation was based upon the analysis, previously reported, of the structures and absorption maxima of compounds studied earlier. A previously unknown substance was prepared, a prototypical target molecule, perfluoro-3-iodocyclopent-1-ene. It was obtained by reaction of perfluorocyclopentene with sulfur trioxide under the influence of antimony pentafluoride catalyst, followed by treatment of the resulting allylic fluorosulfonate with sodium iodide in sulfoland solvent. Preliminary data indicate that the absorption maximum for the iodo fluorocarbon is not shifted significantly to longer wavelength. It is not certain whether this result reflects an unexpected influence of the cyclic structure upon the position of the absorption maximum.

Shiner, C. S.

1986-01-01

14

Advanced solar energy conversion. [solar pumped gas lasers  

NASA Technical Reports Server (NTRS)

An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

Lee, J. H.

1981-01-01

15

SOLAR PUMPED LASER MICROTHRUSTER  

SciTech Connect

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A M; Beach, R; Dawson, J; Siders, C W

2010-02-05

16

Solar Pumped Laser Microthruster  

NASA Astrophysics Data System (ADS)

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W.

2010-10-01

17

Solar Pumped Laser Microthruster  

SciTech Connect

The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.

Rubenchik, A. M.; Beach, R.; Dawson, J.; Siders, C. W. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore CA 94550 (United States)

2010-10-08

18

Solar-pumped solid-state lasers  

Microsoft Academic Search

Results are presented for direct solar pumping of a Nd:YAG rod laser. Stable CW output of more than 60 W was obtained with a slope efficiency exceeding 2 percent. A compound parabolic concentrator, designed to increase the solar radiation coupled into the laser rod, was used in these experiments. The results are consistent with predictions based on a single solar-pumped

M. Weksler; J. Shwartz

1988-01-01

19

Solar-pumped gas laser development  

NASA Technical Reports Server (NTRS)

The direct conversion of solar radiation into an inverted population for extraction in an optical cavity holds promise as a relatively simple system design. Broad-band photoabsorption in the visible or near-UV range is required to excite large volumes of gas and to ensure good solar absorption efficiency. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than approximately 10 A. The system should show chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. A search of electronic-vibrational transitions in diatomic molecules satisfying these conditions is now in progress. A photodissociation-pumped atomic iodine laser is now being tested under solar pumping conditions. Photodissociation studies for thallium spin-flip metastable formation will begin in the near future.

Wilson, J. W.

1981-01-01

20

Feasibility of solar-pumped dye lasers  

NASA Technical Reports Server (NTRS)

Dye laser gains were measured at various pump-beam irradiances on a dye cell in order to evaluate the feasibility of solar pumping. Rhodamine 6G dye was considered as a candidate for the solar-pumped laser because of its high utilization of the solar spectrum and high quantum efficiency. Measurements show that a solar concentration of 20,000 is required to reach the threshold of the dye.

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1987-01-01

21

Prospects for solar-pumped semiconductor lasers  

SciTech Connect

Approaches are discussed for a direct solar-pumped semiconductor laser. Efficiencies of 35% should be achievable, an order of magnitude better than the efficiency achieved by other solar pumped lasers. The output wavelength of a semiconductor laser will be well matched to the optimum conversion efficiency of a solar cell of the same material. Solar pumped semiconductor lasers are thus an excellent candidate for space-based energy-transmission. Recently several designs for such lasers have been proposed. A critical parameter is the sunlight intensity required for lasing. This threshold has been calculated to be in the range of 2,500 to 10,000 times solar intensity for conventional stripe laser designs, depending on assumptions. Several approaches have been recently proposed to reduce this threshold. The calculated minimum threshold is 25--50 times solar concentration, and could possible be reduced even further with use of light-trapping.

Landis, G.A. [W.J. Schafer Associates, Cleveland, OH (United States)

1994-12-31

22

Solar Pumped Lasers and Their Applications  

NASA Technical Reports Server (NTRS)

Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

Lee, Ja H.

1991-01-01

23

Solar pumped lasers and their applications  

NASA Astrophysics Data System (ADS)

Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

Lee, Ja H.

24

Research on solar pumped liquid lasers  

NASA Astrophysics Data System (ADS)

A solar pumped liquid laser that can be scaled up to high power (10Mw CW) for space applications was developed. Liquid lasers have the inherent advantage over gases in that they provide much higher lasant densities and thus high power densities. Liquids also have inherent advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13:Nd(3+):ZrC14 liquid was chosen for its high intrinsic efficiency as well as its relatively good stability against decomposition due to protic contamination. The development and testing of the laser liquid and the development of a large solar concentrator to pump the laser was emphasized. The procedure to manufacture the laser liquid must include diagnostic tests of the solvent purity (from protic contamination) at various stages in the production process.

Schneider, R. T.; Kurzweg, U. H.; Cox, J. D.; Weinstein, N. H.

1983-03-01

25

Research on solar pumped liquid lasers  

NASA Technical Reports Server (NTRS)

A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

Cox, J. D.; Kurzweg, U. H.; Weinstein, N. H.; Schneider, R. T.

1985-01-01

26

Research on solar pumped liquid lasers  

NASA Astrophysics Data System (ADS)

A solar pumped liquid laser that can be scaled up to high power (10 mW CW) for space applications was developed. Liquid lasers have the advantage over gases in that they provide much higher lasant densities and thus high-power densities. Liquids also have advantages over solids in that they have much higher damage thresholds and are much cheaper to produce for large scale applications. Among the liquid laser media that are potential candidates for solar pumping, the POC13: Nd sup 3+:ZrC14 liquid was chosen for its high intrinsic efficiency and its relatively good stability against decomposition due to protic contamination. The development of a manufacturing procedure and performance testing of the laser, liquid and the development of an inexpensive large solar concentrator to pump the laser are examined.

Cox, J. D.; Kurzweg, U. H.; Weinstein, N. H.; Schneider, R. T.

1985-04-01

27

Theoretcial studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A method of pumping a COhZ laser by a hot cavity was demonstrated. The cavity, heated by solar radiation, should increase the efficiency of solar pumped lasers used for energy conversion. Kinetic modeling is used to examine the behavior of such a COhZ laser. The kinetic equations are solved numerically vs. time and, in addition, steady state solutions are obtained analytically. The effect of gas heating filling the lower laser level is included. The output power and laser efficiency are obtained as functions of black body temperature and gas ratios (COhZ-He-Ar) and pressures. The values are compared with experimental results.

Harries, W. L.; Fong, Z. S.

1984-01-01

28

Solar-pumped gas laser development  

NASA Technical Reports Server (NTRS)

A survey of gas properties through detailed kinetic models led to the identification of critical gas parameters for use in choosing appropriate gas combinations for solar pumped lasers. Broadband photoabsorption in the visible or near UV range is required to excite large volumes of gas and to insure good solar absorption efficiency. The photoexcitation density is independent of the absorption bandwidth. The state excited must be a metastable state which is not quenched by the parent gas. The emission bandwidth must be less than 10 A to insure lasing threshold over reasonable gain lengths. The system should show a high degree of chemical reversibility and an insensitivity to increasing temperature. Other properties such as good quantum efficiency and kinetic efficiency are also implied. Although photoexcitation of electronic vibrational transitions is considered as a possible system if the emission bands sufficiently narrow, it appears that photodissociation into atomic metastables is more likely to result in a successful solar pumped laser system.

Wilson, J. W.

1980-01-01

29

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Solar-pumped lasers were investigated by comparing experimental results from pulse experiments with steady state calculations. The time varying behavior of an IBr laser is studied. The analysis is only approximate, but indicates that conditions occurring in a pulsed experiment are quite different from those at steady state. The possibility of steady-state lasing in an IBr laser is determined. The effects of high temperatures on the quenching and recombination rates are examined. Although uncertainties in the values of the rate coefficients make it difficult to draw firm conclusions, it seems steady state running may be possible at high temperatures.

Harries, W. L.

1982-01-01

30

Scaling studies of solar pumped lasers  

NASA Technical Reports Server (NTRS)

A progress report of scaling studies of solar pumped lasers is presented. Conversion of blackbody radiation into laser light has been demonstrated in this study. Parametric studies of the variation of laser mixture composition and laser gas temperature were carried out for CO2 and N2O gases. Theoretical analysis and modeling of the system have been performed. Reasonable agreement between predictions in the parameter variation and the experimental results have been obtained. Almost 200 mW of laser output at 10.6 micron was achieved by placing a small sapphire laser tube inside an oven at 1500 K the tube was filled with CO2 laser gas mixture and cooled by longitudinal nitrogen gas flow.

Christiansen, W. H.; Chang, J.

1985-01-01

31

Preliminary conceptual design and weight of a one-megawatt space-based laser power station utilizing a solar-pumped iodine lasant  

NASA Technical Reports Server (NTRS)

A preliminary conceptual design of a space-based solar-pumped iodide laser emitting 1 MW of laser power for space-to-space power transmission is described. A near-parabolic solar collector focuses sunlight onto the t-C4F9I lasant within a transverse-flow optical cavity. Using waste heat, a thermal system supplies compressor and auxiliary power. The major system components are designed with weight estimates assigned. In particular, it is found that laser efficiency is not a dominant weight factor, the dominant factor being the laser transmission optics. The station mass is 92,000 kg, requiring approximately eight Shuttle flights to LEO, where an orbital transfer vehicle can transport it to the final altitude of 6378 km.

De Young, R. J.; Walker, G. H.; Williams, M. D.; Schuster, G. L.; Conway, E. J.

1987-01-01

32

Solar-pumped laser and its second harmonic generation  

Microsoft Academic Search

Solar radiation concentrated by using a large solar collector was used to optically excite a Nd:YAG laser medium and was successfully converted into coherent laser light. The maximum laser output power attained 60 W in multi-mode. This is the highest power so far reported on a solar-pumped laser. Q-switched pulse operation of the cw solar-pumped ND:YAG laser was performed by

H. Arashi; Y. Kaneda

1993-01-01

33

Key techniques for space-based solar pumped semiconductor lasers  

NASA Astrophysics Data System (ADS)

In space, the absence of atmospheric turbulence, absorption, dispersion and aerosol factors on laser transmission. Therefore, space-based laser has important values in satellite communication, satellite attitude controlling, space debris clearing, and long distance energy transmission, etc. On the other hand, solar energy is a kind of clean and renewable resources, the average intensity of solar irradiation on the earth is 1353W/m2, and it is even higher in space. Therefore, the space-based solar pumped lasers has attracted much research in recent years, most research focuses on solar pumped solid state lasers and solar pumped fiber lasers. The two lasing principle is based on stimulated emission of the rare earth ions such as Nd, Yb, Cr. The rare earth ions absorb light only in narrow bands. This leads to inefficient absorption of the broad-band solar spectrum, and increases the system heating load, which make the system solar to laser power conversion efficiency very low. As a solar pumped semiconductor lasers could absorb all photons with energy greater than the bandgap. Thus, solar pumped semiconductor lasers could have considerably higher efficiencies than other solar pumped lasers. Besides, solar pumped semiconductor lasers has smaller volume chip, simpler structure and better heat dissipation, it can be mounted on a small satellite platform, can compose satellite array, which can greatly improve the output power of the system, and have flexible character. This paper summarizes the research progress of space-based solar pumped semiconductor lasers, analyses of the key technologies based on several application areas, including the processing of semiconductor chip, the design of small and efficient solar condenser, and the cooling system of lasers, etc. We conclude that the solar pumped vertical cavity surface-emitting semiconductor lasers will have a wide application prospects in the space.

He, Yang; Xiong, Sheng-jun; Liu, Xiao-long; Han, Wei-hua

2014-12-01

34

Flow tube used to cool solar-pumped laser  

NASA Technical Reports Server (NTRS)

A flow tube has been designed and constructed to provide two major functions in the application of a laser beam for transmission of both sound and video. It maintains the YAG laser at the proper operating temperature of 300 degrees K under solar pumping conditions, and it serves as a pump cavity for the laser crystal.

1968-01-01

35

Solar pumped laser technology options for space power transmission  

NASA Technical Reports Server (NTRS)

An overview of long-range options for in-space laser power transmission is presented. The focus is on the new technology and research status of solar-pumped lasers and their solar concentration needs. The laser options include gas photodissociation lasers, optically-pumped solid-state lasers, and blackbody-pumped transfer lasers. The paper concludes with a summary of current research thrusts.

Conway, E. J.

1986-01-01

36

Overview and future direction for blackbody solar-pumped lasers  

NASA Technical Reports Server (NTRS)

A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

Deyoung, R. J.

1988-01-01

37

Solar-pumped lasers for space power transmission  

NASA Technical Reports Server (NTRS)

Multi-Megawatt CW solar-pumped lasers appear to be technologically feasible for space power transmission in the 1990s time frame. A new concept for a solar-pumped laser is presented which utilizes an intermediate black body cavity to provide a uniform optical pumping environment for the lasant, either CO or CO2. Reradiation losses are minimized with resulting high efficiency operation. A 1 MW output laser may weigh as little as 8000 kg including solar collector, black body cavity, laser cavity and ducts, pumps, power systems and waste heat radiator. The efficiency of such a system will be on the order of 10 to 20%. Details of the new concept, laser design, comparison to competing solar-powered lasers and applications to a laser solar power satellite (SPS) concept are presented.

Taussig, R.; Bruzzone, C.; Nelson, L.; Quimby, D.; Christiansen, W.

1979-01-01

38

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

This report describes results of NASA Grant NAG-1-1148, entitled Direct Solar Pumping of Semiconductor Lasers: A Feasibility Study. The goals of this study were to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space with directly focused sunlight and to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or storage battery electrically pumping a current injection laser. With external modulation, such lasers could perhaps be efficient sources for intersatellite communications. We proposed specifically to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation at low pump intensities. These tasks have been accomplished, as described in this report of our completed project. The report is organized as follows: Some general considerations relevant to the solar-pumped semiconductor laser problem are discussed in Section 2, and the types of structures chosen for specific investigation are described. The details of the laser model we developed for this work are then outlined in Section 3. In Section 4, results of our study are presented, including designs for optimum lattice-matched and strained-layer solar-pumped quantum-well lasers and threshold pumping estimates for these structures. It was hoped at the outset of this work that structures could be identified which could be expected to operate continuously at solar photoexcitation intensities of several thousand suns, and this indeed turned out to be the case as described in this section. Our project is summarized in Section 5, and information on publications resulting from this work is provided in Section 6.

Anderson, Neal G.

1992-01-01

39

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

Possible types of lasers were surveyed for solar power conversion. The types considered were (1) liquid dye lasers, (2) vapor dye lasers, and (3) nondissociative molecular lasers. These are discussed.

Harries, W. L.

1983-01-01

40

Design of ultrahigh brightness solar-pumped disk laser.  

PubMed

To significantly improve the solar-pumped laser beam brightness, a multi-Fresnel lens scheme is proposed for side-pumping either a single-crystal Nd:YAG or a core-doped ceramic Sm(3+) Nd:YAG disk. Optimum laser system parameters are found through ZEMAX and LASCAD numerical analysis. An ultrahigh laser beam figure of merit B of 53 W is numerically calculated, corresponding to a significant enhancement of more than 180 times over the previous record. 17.7 W/m(2) collection efficiency is also numerically attained. The strong thermal effects that have hampered present-day rod-type solar-pumped lasers can also be largely alleviated. PMID:22968278

Liang, Dawei; Almeida, Joana

2012-09-10

41

One-megawatt solar pumped and electrically driven lasers for space power transmission  

NASA Technical Reports Server (NTRS)

High power lasers in space could provide power for a variety of future space missions such as spacecraft electric power requirements and laser propulsion. This study investigates four electrically pumped laser systems, krypton fluoride, copper vapor, laser diode array, and the carbon dioxide laser, all scaled to 1-MW laser output. Each system obtained its primary power from a large solar photovoltaic array which, in turn, provides power for the appropriate laser power conditioning subsystem. Each system was block-diagrammed, and the power and efficiency were found for each subsystem. The laser diode array had the highest solar-to-laser efficiency (6 percent) and smallest radiator area making it the most advantageous of the electrically driven lasers studied. This system was then compared with an iodine solar pumped laser system previously studied. The diode array had a better wavelength with regard to transmission optics mass, but it also had a heavier radiator because of its lower temperature radiator requirement. A more advanced solar pumped laser could emerge as the preferred laser system for space applications.

Deyoung, R. J.; Lee, J. H.; Williams, M. D.; Schuster, G.; Conway, E. J.

1988-01-01

42

A new concept for solar pumped lasers  

NASA Technical Reports Server (NTRS)

A new approach is proposed in which an intermediate body heated by sunlight is used as the pumping source for IR systems, i.e., concentration solar radiation is absorbed and reradiated via an intermediate blackbody. This body is heated by focused sunlight to a high temperature and its heat losses are engineered to be small. The cooled laser tube (or tubes) is placed within the cavity and is pumped by it. The advantage is that the radiation spectrum is like a blackbody at the intermediate temperature and the laser medium selectively absorbs this light. Focusing requirements, heat losses, and absorption bandwidths of laser media are examined, along with energy balance and potential efficiency. The results indicate that for lasers pumped through an IR absorption spectrum, the use of an intermediate blackbody offers substantial and important advantages. The loss in radiative intensity for optical pumping by a lower-temperature body is partly compensated by the increased solid angle of exposure to the radiative environment.

Christiansen, W. H.

1978-01-01

43

Solar-Pumped TEM?? Mode Nd:YAG laser.  

PubMed

Here we show a significant advance in solar-pumped laser beam brightness by utilizing a 1.0 m diameter Fresnel lens and a 3 mm diameter Nd:YAG single-crystal rod. The incoming solar radiation is firstly focused by the Fresnel lens on a solar tracker. A large aspheric lens and a 2D-CPC concentrator are then combined to further compress the concentrated solar radiation along the thin laser rod within a V-shaped pumping cavity. 2.3 W cw TEM?? (M² ? 1.1) solar laser power is finally produced, attaining 1.9 W laser beam brightness figure of merit, which is 6.6 times higher than the previous record. For multimode operation, 8.1 W cw laser power is produced, corresponding to 143% enhancement in collection efficiency. PMID:24150353

Liang, Dawei; Almeida, Joana

2013-10-21

44

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

The primary goals of the feasibility study are the following: (1) to provide a preliminary assessment of the feasibility of pumping semiconductor lasers in space directly focused sunlight; and (2) to identify semiconductor laser structures expected to operate at the lowest possible focusing intensities. It should be emphasized that the structures under consideration would provide direct optical-to-optical conversion of sunlight into laser light in a single crystal, in contrast to a configuration consisting of a solar cell or battery electrically pumping a current injection laser. With external modulation, such lasers may prove to be efficient sources for intersatellite communications. We proposed to develop a theoretical model of semiconductor quantum-well lasers photopumped by a broadband source, test it against existing experimental data where possible, and apply it to estimating solar pumping requirements and identifying optimum structures for operation for operation at low pump intensities. This report outlines our progress toward these goals. Discussion of several technical details are left to the attached summary abstract.

Anderson, Neal G.

1991-01-01

45

Highly efficient solar-pumped Nd:YAG laser.  

PubMed

The recent progress in solar-pumped laser with Fresnel lens and Cr:Nd:YAG ceramic medium has revitalized solar laser researches, revealing a promising future for renewable reduction of magnesium from magnesium oxide. Here we show a big advance in solar laser collection efficiency by utilizing an economical Fresnel lens and a most widely used Nd:YAG single-crystal rod. The incoming solar radiation from the sun is focused by a 0.9 m diameter Fresnel lens. A dielectric totally internally reflecting secondary concentrator is employed to couple the concentrated solar radiation from the focal zone to a 4 mm diameter Nd:YAG rod within a conical pumping cavity. 12.3 W cw laser power is produced, corresponding to 19.3 W/m(2) collection efficiency, which is 2.9 times larger than the previous results with Nd:YAG single-crystal medium. Record-high slope efficiency of 3.9% is also registered. Laser beam quality is considerably improved by pumping a 3 mm diameter Nd:YAG rod. PMID:22274224

Liang, Dawei; Almeida, Joana

2011-12-19

46

Efficiency and threshold pump intensity of CW solar-pumped solid-state lasers  

NASA Technical Reports Server (NTRS)

The authors consider the relation between the threshold pumping intensity, the material properties, the resonator parameters, and the ultimate slope efficiencies of various solid-state laser materials for solar pumping. They clarify the relation between the threshold pump intensity and the material parameters and the relation between the ultimate slope efficiency and the laser resonator parameters such that a design criterion for the solar-pumped solid-state laser can be established. Among the laser materials evaluated, alexandrite has the highest slope efficiency of about 12.6 percent; however, it does not seem to be practical for a solar-pumped laser application because of its high threshold pump intensity. Cr:Nd:GSGG is the most promising for solar-pumped lasing. Its threshold pump intensity is about 100 air-mass-zero (AM0) solar constants and its slope efficiency is about 12 percent when thermal deformation is completely prevented.

Hwang, In H.; Lee, Ja H.

1991-01-01

47

Development of Nd,Cr co-doped laser materials for solar-pumped lasers  

NASA Astrophysics Data System (ADS)

Solar-pumped laser has attracted attention in the area of renewable energy creation. However, since the conversion efficiency from solar energy to laser energy is low, such lasers are not yet in practical use. In this work, we developed Nd3+,Cr3+ codoped YVO4 and CaYAlO4 crystals for solar-pumped laser. We succeeded to increase absorption at UV-VIS region with both crystals drastically. The absorption cross section of Nd,Cr:CaYAlO4 around 400 nm was more than 70 times that of Nd,Cr:YAG crystals. The fluorescence at 1 ?m was observed by pumping at 400 nm. It indicates that energy transfer from Cr to Nd occurred effectively.

Ogawa, Takayo; Wada, Satoshi; Higuchi, Mikio

2014-02-01

48

A solar simulator-pumped atomic iodine laser  

NASA Technical Reports Server (NTRS)

An atomic iodine laser, a candidate for the direct solar-pumped gas laser, was excited with a 4-kW beam from a xenon arc solar simulator. Continuous lasing at 1.315 micron for over 10 ms was obtained for static filling of n-C3F7I vapor. By momentarily flowing the lasant, a 30-Hz pulsed output was obtained for about 200 ms. The peak laser power observed was 4 W for which the system efficiency reached 0.1%. These results indicate that direct solar pumping of a gas laser for power conversion in space is indeed feasible.

Lee, J. H.; Weaver, W. R.

1981-01-01

49

A solar-pumped CW 18 W Nd:YAG laser  

Microsoft Academic Search

The development of a solar-pumped Nd:YAG laser is reported. A solar energy collector consisting of a paraboloidal mirror 10 m in aperture and 3.2 m in focal length is used to pump a water-cooled Nd:YAG laser rod 4 mm in diameter and 75 mm in length. The maximum output of the laser is 18 W in multi-mode, the highest output

Haruo Arashi; Yasuo Oka; Nenokichi Sasahara; Atsushi Kaimai; Mareo Ishigame

1984-01-01

50

Development of Nd,Cr co-doped laser materials for solar-pumped lasers  

NASA Astrophysics Data System (ADS)

Solar-pumped lasers have attracted attention in the area of renewable energy creation. However, since the conversion efficiency from solar energy to laser energy is low, such lasers are not yet in practical use. In this work, we grew and evaluated Nd3+,Cr3+-co-doped YVO4 and CaYAlO4 crystals for solar-pumped lasers. We succeeded in dramatically increasing the absorption from the ultraviolet to visible region using both crystals. The maximum absorption coefficient was 58 cm-1 at 402 nm for 1.0 at. % Cr-co-doped Nd:YVO4 crystal. The absorption coefficient of Nd,Cr:CaYAlO4 reached 52 cm-1 at 430 nm in the case of 0.1 at. % Cr doping. Strong fluorescence at 1 µm was observed upon pumping Nd,Cr:YVO4 at 400 nm. The result indicates effective energy transfer from Cr to Nd occurred in the Nd,Cr:YVO4.

Ogawa, Takayo; Wada, Satoshi; Higuchi, Mikio

2014-08-01

51

A solar-pumped Nd:YAG laser in the high collection efficiency regime  

Microsoft Academic Search

Solar-pumped lasers can be used for space and terrestrial applications. We report on solar side-pumped Nd:YAG laser experiments, which included comprehensive beam quality measurements and demonstrated record collection efficiency and day long operation. A 6.75 m2 segmented primary mirror was mounted on a commercial two-axis positioner and focused the solar radiation towards a stationary non-imaging-optics secondary concentrator, which illuminated a

Mordechai Lando; Jacob Kagan; Boris Linyekin; Vadim Dobrusin

2003-01-01

52

Analysis of Nd3+:glass, solar-pumped, high-powr laser systems  

NASA Technical Reports Server (NTRS)

The operating characteristics of Nd(3+):glass lasers energized by a solar concentrator were analyzed for the hosts YAG, silicate glass, and phosphate glass. The modeling is based on the slab zigzag laser geometry and assumes that chemical hardening methods for glass are successful in increasing glass hardness by a factor of 4. On this basis, it was found that a realistic 1-MW solar-pumped laser might be constructed from phosphate glass 4 sq m in area and 2 mm thick. If YAG were the host medium, a 1-MW solar-pumped laser need only be 0.5 sq m in area and 0.5 cm thick, which is already possible. In addition, Nd(3+) doped glass fibers were found to be excellent solar-pumped laser candidates. The small diameter of fibers eliminates thermal stress problems, and if their diameter is kept small (10 microns), they propagate a Gaussian single mode which can be expanded and transmitted long distances in space. Fiber lasers could then be used for communications in space or could be bundled and the individual beams summed or phase-matched for high-power operation.

Zapata, L. E.; Williams, M. D.

1989-01-01

53

Solar-pumped 80 W laser irradiated by a Fresnel lens.  

PubMed

A solar-pumped 100 W class laser that features high efficiency and low cost owing to the use of a Fresnel lens and a chromium codoped neodymium YAG ceramic laser medium was developed. A laser output of about 80 W was achieved with combination of a 4 m(2) Fresnel lens and a pumping cavity as a secondary power concentrator. This output corresponds to 4.3% of conversion efficiency from solar power into laser, and the maximum output from a unit area of Fresnel lens was 20 W/m(2), which is 2.8 times larger than previous results with mirror-type concentrator. PMID:19148246

Ohkubo, Tomomasa; Yabe, Takashi; Yoshida, Kunio; Uchida, Shigeaki; Funatsu, Takayuki; Bagheri, Behgol; Oishi, Takehiro; Daito, Kazuya; Ishioka, Manabu; Nakayama, Yuichirou; Yasunaga, Norihito; Kido, Kouichirou; Sato, Yuji; Baasandash, Choijil; Kato, Kiyoshi; Yanagitani, Takagimi; Okamoto, Yoshiaki

2009-01-15

54

Intensity and absorbed-power distribution in a cylindrical solar-pumped dye laser  

NASA Technical Reports Server (NTRS)

The internal intensity and absorbed-power distribution of a simplified hypothetical dye laser of cylindrical geometry is calculated. Total absorbed power is also calculated and compared with laboratory measurements of lasing-threshold energy deposition in a dye cell to determine the suitability of solar radiation as a pump source or, alternatively, what modifications, if any, are necessary to the hypothetical system for solar pumping.

Williams, M. D.

1984-01-01

55

Threshold pump power of a solar-pumped dye laser  

NASA Technical Reports Server (NTRS)

Threshold solar power for dye laser pumping has been determined by measuring the gain of a rhodamine 6G dye laser amplifier at various solar-simulated irradiances on an amplifier cell. The measured threshold was 20,000 solar constants (2.7 kW/sq cm) for the dye volume of 2 x 5 x 40 cu mm and the optimum dye concentration of 0.001 M. The threshold is about one-third of that achievable with a high-intensity solar concentrator.

Lee, Ja H.; Kim, Kyung C.; Kim, Kyong H.

1988-01-01

56

Passive Q switching of a solar-pumped Nd:YAG laser.  

PubMed

Passive Q switching is a preferable choice for switching the Q factor of a solar-pumped laser because it requires neither a driver nor an electrical power supply. The superior thermal characteristics and durability of Cr(4+):YAG single crystals as passive Q switches for lamp and diode-pumped high-power lasers has been demonstrated. Here we report on an average power of 37 W and a switching efficiency of 80% obtained by use of a solar-pumped Nd:YAG laser Q switched by a Cr(4+):YAG saturable absorber. Concentration of the pumping solar energy on the laser crystal was obtained with a three-stage concentrator, composed of 12 heliostats, a three-dimensional compound parabolic concentrator (CPC) and a two-dimensional CPC. The water-cooled passive Q switch also served as the laser rear mirror. Repetition rates of as much as 50 kHz, at pulse durations between 190 and 310 ns (FWHM) were achieved. From the experimental results, the saturated single-pass power absorption of the Cr(4+):YAG device was estimated as 3 ? 1%. PMID:18345094

Lando, M; Shimony, Y; Noter, Y; Benmair, R M; Yogev, A

2000-04-20

57

Efficient solar-pumped Nd:YAG laser by a double-stage light-guide\\/V-groove cavity  

Microsoft Academic Search

Since the first reported Nd:YAG solar laser, researchers have been exploiting parabolic mirrors and heliostats for enhancing laser output performance. We are now investigating the production of an efficient solar-pumped laser for the reduction of magnesium from magnesium oxide, which could be an alternative solution to fossil fuel. Therefore both high conversion efficiency and excellent beam quality are imperative. By

Joana Almeida; Dawei Liang

2011-01-01

58

a 57 W Solar-Pumped Neodymium-Doped YAG Laser  

NASA Astrophysics Data System (ADS)

An experiment conducted recently at the National Renewable Energy Laboratory has demonstrated world record efficiency for directly solar-pumped lasers. Using the High Flux Solar Furnace test facility and a tailored non -imaging secondary concentrator, a Nd:YAG crystal lased with a peak power of 57 +/- 1 W. With the primary mirror area of 12.12 m^2, each square meter of the mirror surface converted sunlight into nearly 5 W of laser power. This is the highest value ever measured at laser power levels >5 W. Deviations from ideal conditions, such as lack of precision in the furnace's sun tracking and atmospheric effects, can greatly lower performance and stability. Beam quality studies show that high-brightness lasing is achieveable, but that thermal stresses inside the laser crystal led to unforeseen problems. The implications of this experiment on future solar laser research are discussed.

Jenkins, David Gerard

59

Identification and properties of molecular systems of potential use in solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The concepts and computational tools of theortical chemistry are used to investigate molecular properties needed in direct solar-pumped lasers. Compounds of the type RR'CXY, with R and R' organic groups, and X and Y halide atoms were identified as likely candidates because of their highly enhanced absorption coefficients over compounds with a single halide atom. The use of a combination of vibrational excitation followed by electronic excitation to enhance quantum yields at certain wavelengths is indicated. A self-consistent eikonal approximation to state-to-state transitions was tested for CH3I and is useful for other problems involving electronic energy and charge transfer. An approach to calculate potential energy surfaces and transition dipoles was developed which is based on the generation of eigenstates of the nonrelativisitc Hamiltonian followed by incorporation of the spin-orbit coupling by configuration interaction.

Micha, D. A.; Oehrn, N. Y.

1985-01-01

60

Development of solar concentrators for high-power solar-pumped lasers.  

PubMed

We have developed unique solar concentrators for solar-pumped solid-state lasers to improve both efficiency and laser output power. Natural sunlight is collected by a primary concentrator which is a 2??m×2??m Fresnel lens, and confined by a cone-shaped hybrid concentrator. Such solar power is coupled to a laser rod by a cylinder with coolant surrounding it that is called a liquid light-guide lens (LLGL). Performance of the cylindrical LLGL has been characterized analytically and experimentally. Since a 14 mm diameter LLGL generates efficient and uniform pumping along a Nd:YAG rod that is 6 mm in diameter and 100 mm in length, 120 W cw laser output is achieved with beam quality factor M2 of 137 and overall slope efficiency of 4.3%. The collection efficiency is 30.0??W/m2, which is 1.5 times larger than the previous record. The overall conversion efficiency is more than 3.2%, which can be comparable to a commercial lamp-pumped solid-state laser. The concept of the light-guide lens can be applied for concentrator photovoltaics or other solar energy optics. PMID:24787600

Dinh, T H; Ohkubo, T; Yabe, T

2014-04-20

61

Design of high-brightness TEM00-mode solar-pumped laser for renewable material processing  

NASA Astrophysics Data System (ADS)

The conversion of sunlight into laser light by direct solar pumping is of ever-increasing importance because broadband, temporally constant, sunlight is converted into laser light, which can be a source of narrowband, collimated, rapidly pulsed, radiation with the possibility of obtaining extremely high brightness and intensity. Nonlinear processes, such as harmonic generation, might be used to obtain broad wavelength coverage, including the ultraviolet wavelengths, where the solar flux is very weak. The direct excitation of large lasers by sunlight offers the prospect of a drastic reduction in the cost of coherent optical radiation for high average power materials processing. This renewable laser has a large potential for many applications such as high-temperature materials processing, renewable magnesium-hydrogen energy cycle and so on. We propose here a scalable TEM00 mode solar laser pumping scheme, which is composed of four firststage 1.13 m diameter Fresnel lenses with its respective folding mirrors mounted on a two-axis automatic solar tracker. Concentrated solar power at the four focal spots of these Fresnel lenses are focused individually along a common 3.5 mm diameter, 70 mm length Nd:YAG rod via four pairs of second-stage fused-silica spherical lenses and third-stage 2D-CPCs (Compound Parabolic Concentrator), sitting just above the laser rod which is also double-pass pumped by four V-shaped pumping cavities. Distilled water cools both the rod and the concentrators. 15.4 W TEM00 solar laser power is numerically calculated, corresponding to 6.7 times enhancement in laser beam brightness.

Liang, D.; Almeida, J.

2014-08-01

62

Analysis of a 10 megawatt space-based solar-pumped neodymium laser system  

NASA Technical Reports Server (NTRS)

A ten megawatt solar-pumped continuous liquid laser system for space applications is examined. It is found that a single inflatable mirror of 434 m diameter used in conjunction with a conical secondary concentrator is sufficient to side pump a liquid neodymium lasant in an annular tube of 6 m length and 1 m outer and 0.8 m inner diameter. About one fourth of intercepted radiation converging on the laser tube is absorbed and one fifth of this radiation is effective in populating the upper levels. The liquid lasant is flowed through the annular laser cavity at 1.9 m/s and is cooled via a heat exchanger and a large radiator surface comparable in size to the concentrating mirror. The power density of incident light within the lasant of approximately 68 watt/cu cm required for cw operation is exceeded in the present annular configuration. Total system weight corresponds to 20,500 kg and is thus capable of being transported to near Earth orbit by a single shuttle flight.

Kurweg, U. H.

1984-01-01

63

Silicon photovoltaic cells coupled with solar-pumped fiber lasers emitting at 1064 nm  

NASA Astrophysics Data System (ADS)

We have designed silicon (Si) photovoltaic (PV) cells coupled with solar-pumped fiber lasers (SPFLs), by considering the unique illumination conditions for PV cells: (1) monochromatic (1064 nm) and normal incidence, (2) large intensity, and (3) small area. We have revealed that a multilayered bandpass filter formed on the front surface of a PV cell equipped with a diffuse reflector on the back surface sufficiently traps the illumination. This, in turn, allows us to use a thin Si wafer to eliminate the detrimental effect of the series resistance in the cell under intense illumination, along with a small lateral size that is suitable for direct connection with an SPFL. Simulated conversion efficiency of the newly designed 20 ?m-thick Si PV cell with the 14-layerd bandpass filter and Lambertian back reflector is 61% under normally incident 1064 nm illumination at 1 kW/cm2, which is twice as high as that of a conventional surface-textured Si solar cell of 75 ?m in thickness.

Takeda, Yasuhiko; Iizuka, Hideo; Mizuno, Shintaro; Hasegawa, Kazuo; Ichikawa, Tadashi; Ito, Hiroshi; Kajino, Tsutomu; Ichiki, Akihisa; Motohiro, Tomoyoshi

2014-07-01

64

Systems efficiency and specific mass estimates for direct and indirect solar-pumped closed-cycle high-energy lasers in space  

NASA Technical Reports Server (NTRS)

Based on expected advances in technology, the maximum system efficiency and minimum specific mass have been calculated for closed-cycle CO and CO2 electric-discharge lasers (EDL's) and a direct solar-pumped laser in space. The efficiency calculations take into account losses from excitation gas heating, ducting frictional and turning losses, and the compressor efficiency. The mass calculations include the power source, radiator, compressor, fluids, ducting, laser channel, optics, and heat exchanger for all of the systems; and in addition the power conditioner for the EDL's and a focusing mirror for the solar-pumped laser. The results show the major component masses in each system, show which is the lightest system, and provide the necessary criteria for solar-pumped lasers to be lighter than the EDL's. Finally, the masses are compared with results from other studies for a closed-cycle CO2 gasdynamic laser (GDL) and the proposed microwave satellite solar power station (SSPS).

Monson, D. J.

1978-01-01

65

Characteristics of an all gas-phase iodine laser using molecular iodine as atomic iodine donor  

Microsoft Academic Search

The laser action of an all gas-phase iodine laser (AGIL), which uses molecular iodine as a source of iodine atoms, has been demonstrated. The laser is based on the energy transfer reaction between metastable NCl(a 1Delta) and ground state I(2P3\\/2) atoms, which are produced by the electric discharge of a mixture of I2 and He. At fixed flow rates of

Taizo Masuda; Tomonari Nakamura; Masamori Endo

2010-01-01

66

Design of a formation of solar pumped lasers for asteroid deflection  

NASA Astrophysics Data System (ADS)

This paper presents the design of a multi-spacecraft system for the deflection of asteroids. Each spacecraft is equipped with a fibre laser and a solar concentrator. The laser induces the sublimation of a portion of the surface of the asteroid, and the resultant jet of gas and debris thrusts the asteroid off its natural course. The main idea is to have a formation of spacecraft flying in the proximity of the asteroid with all the spacecraft beaming to the same location to achieve the required deflection thrust. The paper presents the design of the formation orbits and the multi-objective optimisation of the formation in order to minimise the total mass in space and maximise the deflection of the asteroid. The paper demonstrates how significant deflections can be obtained with relatively small sized, easy-to-control spacecraft.

Vasile, Massimiliano; Maddock, Christie Alisa

2012-10-01

67

Design of a Formation of Solar Pumped Lasers for Asteroid Deflection  

E-print Network

This paper presents the design of a multi-spacecraft system for the deflection of asteroids. Each spacecraft is equipped with a fibre laser and a solar concentrator. The laser induces the sublimation of a portion of the surface of the asteroid. The jet of gas and debris thrusts the asteroid off its natural course. The main idea is to have a swarm of spacecraft flying in the proximity of the asteroid with all the spacecraft beaming to the same location to achieve the required deflection thrust. The paper presents the design of the formation orbits and the multi-objective optimization of the swarm in order to minimize the total mass in space and maximize the deflection of the asteroid. The paper demonstrates how significant deflections can be obtained with relatively small sized, easy-to-control spacecraft.

Vasile, Massimiliano

2012-01-01

68

An all gas-phase iodine laser using molecular iodine as atomic iodine donor  

Microsoft Academic Search

The characteristics of an all gas-phase iodine laser (AGIL) that uses molecular iodine as a source of iodine atoms is studied. The laser is based on the energy transfer reaction between metastable NCl(a1Delta) and ground state I(2P3\\/2) atoms, which are produced by the electric discharge of a mixture of I2 and He. At fixed flow rates of the chemical species,

Taizo Masuda; Tomonari Nakamura; Masamori Endo

2010-01-01

69

A electroionization chemical hydrogen-iodine laser  

Microsoft Academic Search

The feasibility of creating a hydrogen-iodine laser with an electroionization excitation capability which operates at the 2P(1\\/2)-2P(3\\/2) magnetodipole transition in atomic iodine (lambda = 1.315 microns) is studied. The atomic iodine needed for the H2-Ar:I2 mixture can be obtained in the electric-discharge-induced fast chemical reaction H + I2 yields HI + I. Based on the analysis of the basic processes

I. M. Bel'Diugin; A. A. Stepanov; V. A. Shcheglov; Iu. P. Vysotskii

1987-01-01

70

A electroionization chemical hydrogen-iodine laser  

NASA Astrophysics Data System (ADS)

The feasibility of creating a hydrogen-iodine laser with an electroionization excitation capability which operates at the 2P(1/2)-2P(3/2) magnetodipole transition in atomic iodine (lambda = 1.315 microns) is studied. The atomic iodine needed for the H2-Ar:I2 mixture can be obtained in the electric-discharge-induced fast chemical reaction H + I2 yields HI + I. Based on the analysis of the basic processes and the calculation of the electron-distribution function, a numerical simulation of a similar laser is carried out. It is shown that the specific energy input required for the development of the hydrogen-iodine laser is sufficiently high (about 250-300 J/l atm) and that the mixture has an optimum with regard to energy input and initial temperature.

Bel'Diugin, I. M.; Stepanov, A. A.; Shcheglov, V. A.; Vysotskii, Iu. P.

1987-02-01

71

120 watt continuous wave solar-pumped laser with a liquid light-guide lens and an Nd:YAG rod.  

PubMed

We propose a simple and efficient pumping approach for a high-power solar-pumped laser by using a liquid light-guide lens (LLGL) and a hybrid pumping cavity. A 2×2 m Fresnel lens is used as a primary concentrator to collect natural sunlight; 120 W cw laser power and a 4.3% total slope efficiency are achieved with a 6-mm diameter Nd:YAG rod within a 14-mm diameter LLGL. The corresponded collection efficiency is 30.0 W/m(2), which is 1.5 times larger than the previous record. This result is unexpectedly better than that of Cr:Nd:YAG ceramics. It is because the scattering coefficient of Cr:Nd:YAG ceramics is 0.004cm(1), which is 2 times larger than that of the Nd:YAG crystal, although both have similar saturation gains. PMID:22743490

Dinh, T H; Ohkubo, T; Yabe, T; Kuboyama, H

2012-07-01

72

Characteristics of an all gas-phase iodine laser using molecular iodine as atomic iodine donor  

NASA Astrophysics Data System (ADS)

The laser action of an all gas-phase iodine laser (AGIL), which uses molecular iodine as a source of iodine atoms, has been demonstrated. The laser is based on the energy transfer reaction between metastable NCl(a 1?) and ground state I(2P3/2) atoms, which are produced by the electric discharge of a mixture of I2 and He. At fixed flow rates of the chemical species, the laser output powers are measured at three different positions in a flow reactor. The output power is characterized by a function of the optical axis position and is in reasonable agreement with the numerical simulation. A repetitive pulse of laser output at 50 Hz with a duty factor of 40% is observed. The highest output power is 40 mW at 210 mm downstream from the mixing point of I/H/He and NCl3. This is 80% of the output power generated from the conventional system using HI as an iodine donor. The measured results of the time-resolved laser output power suggest that the output power of the I2-AGIL is more sensitive to the electric discharge plasma intensity as compared with that of the HI-AGIL. An AGIL operated using I2 could potentially have the same output power as that of an AGIL operated using HI if a continuous-wave electric discharge generator is used.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

2010-10-01

73

Overview of iodine generation for oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

A review of the methods for generation of iodine for oxygen-iodine lasers (OIL) is presented. The chemical and physical methods for production of both atomic (AI) and molecular (MI) iodine have been searched in order to improve the efficiency and/or technology of OILs. These trials were motivated by the estimations that a substantial part of singlet oxygen (SO) could be saved with these methods and the onset of the laser active medium will be accelerated. Vapour of MI can be generated by the evaporation of solid or pressurized liquid I2, or synthesized in situ by the reaction of Cl2 with either HI or CuI2. The chemical methods of generation of AI are based on the substitution of I atom in a molecule of HI or ICl by another halogen atom produced usually chemically. The discharge methods include the dissociation of various iodine compounds (organic iodides, I2, HI) in the RF, MW, DC-pulsed or DC-vortex stabilized discharge. Combined methods use discharge dissociation of molecules (H2, F2) to gain atoms which subsequently react to replace AI from the iodine compound. The chemical methods were quite successful in producing AI (up to the 100% yield), but the enhancement of the laser performance was not reported. The discharge methods had been subsequently improving and are today able to produce up to 0.4 mmol/s of AI at the RF power of 500 W. A substantial enhancement of the discharge- OIL performance (up to 40%) was reported. In the case of Chemical-OIL, the enhancement was reported only under the conditions of a low I2/O2 ratio, where the "standard" I2 dissociation by SO is slow. The small-signal gain up to 0.3 %/cm was achieved on the supersonic COIL using the HI dissociated in the RF discharge. Due to the complicated kinetics of the RI-I-I2-SO system and a strong coupling with the gas flow and mixing, the theoretical description of the problem is difficult. It, however, seems that we can expect the major improvement of the OIL performance for those systems, where the SO yield is rather low (DOIL) or for the high-pressure COIL, where the quenching processes are important and the shortage of the distance needed for the preparation of active media is essential.

Jirásek, Vít.

2012-01-01

74

An all gas-phase iodine laser using molecular iodine as atomic iodine donor  

NASA Astrophysics Data System (ADS)

The characteristics of an all gas-phase iodine laser (AGIL) that uses molecular iodine as a source of iodine atoms is studied. The laser is based on the energy transfer reaction between metastable NCl(a1?) and ground state I(2P3/2) atoms, which are produced by the electric discharge of a mixture of I2 and He. At fixed flow rates of the chemical species, the laser output powers are measured at three different positions in a flow reactor. The output power is characterized by a function of the optical axis position and is reasonably reproduced by the numerical calculation. A repetitive pulse of laser output at 50 Hz with a duty factor of 40% is observed. The highest output power is 40 mW at 210 mm downstream from the mixing point of I/H/He and NCl3. This is 80% of the output power generated from the conventional system using HI as an iodine donor. The measured results of the time resolved laser output power suggest that the output power of the I2- AGIL is more sensitive to the electric discharge plasma intensity as compared to that of the HI-AGIL. An AGIL operated using I2 could potentially have the same output power as that of an AGIL operated using HI if a continuous-wave electric discharge generator is used.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

2010-09-01

75

Comparison between the perfomance of Nd:YAG, Nd/Cr:GSGG and Nd/Cr:YAG ceramic lasers with quasi-solar pumping  

NASA Astrophysics Data System (ADS)

Recent developments in laser materials, such as Nd/Cr:YAG ceramic with a broad absorption spectrum in the visible, have been applied to achieve highly-efficient and low-cost optical pumping by conventional sources. Our simulator based on the implementation of a mathematical model under Matlab Simulink allowed us to show the correlation between the characteristics of the laser mode of operation (such as Relaxation, Quasi-continuous wave (QCW), Continuous wave, Burst, Q-switched) and the various physical parameters of the oscillator. This model was applied to the Nd:YAG crystal, Nd/Cr:GSGG crystal and Nd/Cr:YAG ceramic. The simulation results demonstrated that Nd/Cr:YAG ceramic is an excellent candidate for solar and quasi-solar pumping, as its pumping efficiency exceeds by a factor of four that of the Nd:YAG crystal medium, and by a factor of two that of Nd/Cr:GSGG crystal. A pumping by a light guide was considered in this simulation.

Bouadjemine, R.; Louhibi, D.; Kellou, A.

2015-01-01

76

Parametric study of chemical oxygen iodine laser  

Microsoft Academic Search

An efficient chemical oxygen iodine laser system (COIL) intended for industrial applications was studied parametrically. Employing dilute hydrogen peroxide the system can operate stably at 1kW for 10 minutes with 23.6 percent chemical efficiency, achieving stable operation over 30 minutes at about 500 W under optimized conditions. The practicability of high trap temperature operation was certified, obtaining 800 W power

T. Sawano; S. Yoshida

1990-01-01

77

Laser transmutation of iodine-129  

Microsoft Academic Search

We report the first successful laser-induced transmutation of 129I, one of the key radionuclides in the nuclear fuel cycle. 129I with a half-life of 15.7 million years is transmuted into 128I with a half-life of 25 min through a (?, n) reaction using laser-generated Bremsstrahlung. The integral cross-section value for the (?, n) reaction is determined. These experiments offer a new

J. Magill; H. Schwoerer; F. Ewald; J. Galy; R. Schenkel; R. Sauerbrey

2003-01-01

78

Chemical kinetics of discharge-driven oxygen-iodine lasers  

Microsoft Academic Search

Oxygen-iodine lasers that utilize electrical discharges to produce O2(a1Delta) are currently being developed. The discharge generators differ from those used in chemical oxygen-iodine lasers in that they produce significant amounts of atomic oxygen and traces of ozone. As a consequence of these differences, the chemical kinetics of the discharge laser are markedly different from those of a conventional chemical oxygen-iodine

Valeriy N. Azyazov; Ivan O. Antonov; Michael C. Heaven

2007-01-01

79

Chemical generation of atomic iodine for chemical oxygen–iodine laser. I. Modelling of reaction systems  

Microsoft Academic Search

The mathematical modelling of reaction systems for chemical generation of atomic iodine is presented. This process is aimed to be applied in the chemical oxygen–iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. In the suggested method, gaseous reactants for I atoms generation are admixed into the

V??t Jirásek; Otomar Špalek; Jarmila Kodymová; Miroslav ?enský

2001-01-01

80

Pulsed chemical oxygen—iodine laser with bulk formation of iodine atoms by an electric discharge  

Microsoft Academic Search

A preliminary investigation was made of a chemical oxygen—iodine laser with bulk formation of iodine atoms in an electric discharge. The output energy was comparable with that obtained for a photolysis variant of the laser, but the technical efficiency of the investigated discharge variant was much higher (91%). The pulse power (~100 kW) was approximately three orders of magnitude higher

Nikolai P Vagin; V S Pazyuk; Nikolai N Yuryshev

1995-01-01

81

LASERS: Pulsed chemical oxygen—iodine laser with bulk formation of iodine atoms by an electric discharge  

NASA Astrophysics Data System (ADS)

A preliminary investigation was made of a chemical oxygen—iodine laser with bulk formation of iodine atoms in an electric discharge. The output energy was comparable with that obtained for a photolysis variant of the laser, but the technical efficiency of the investigated discharge variant was much higher (91%). The pulse power (~100 kW) was approximately three orders of magnitude higher than the power of a cw chemical oxygen—iodine laser with the same chlorine flow rate.

Vagin, Nikolai P.; Pazyuk, V. S.; Yuryshev, Nikolai N.

1995-08-01

82

Modeling of the chemical generation of atomic iodine in a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The mathematical modeling of reaction systems for chemical generation of atomic iodine is presented. This process can be applied in the chemical oxygen-iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. The parametric study of the production of atomic fluorine and subsequently atomic iodine in dependence on the pressure and dilution with inert gas was made. The calculation of the interaction between produced atomic iodine and singlet oxygen was made with four different mixing/reacting schemes.

Jirasek, Vit; Spalek, Otomar; Kodymova, Jarmila; Censky, Miroslav

2002-05-01

83

Feasibility of an iodine gas laser pumped by concentrated terrestrial solar radiation  

SciTech Connect

A t-C{sub 4}F{sub 9}I iodine gas laser pumped by terrestrial sunlight was analyzed. Lasant properties, spectral terrestrial insolation data, and established laser fundamentals were used to develop a mathematical model of a terrestrial solar-pumped system. Threshold pumping power and available terrestrial pumping power were predicted and used to estimate the solar concentration required to initiate lasing. Laser output power was also predicted. Because this lasant is relatively new and has never been pumped by solar radiation, many physical properties are not well known. An uncertainty analysis was used to predict errors in threshold solar concentration and output power. In all cases, conservative estimates of physical properties were used. The dominant uncertainty in both threshold and output predictions was due to wide variation in published values of the quenching reaction caused by the lasant parent molecule. Several optical and geometric configurations were devised using commercially available primary solar collectors: parabolic or compound parabolic troughs, a Shenandoah-type 7.5 meter diameter parabolic dishes, or a 17 meter diameter stretched membrane dish. Threshold solar concentration for these systems ranged from below 50 to almost 200 suns depending on the laser tube geometry. Output power ranged from below 1 Watt to almost 90 Watts, and was a function of primary collector dimension.

Terry, C.K.; Peterson, J.E.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

1995-11-01

84

LASERS: Pulsed chemical oxygen---iodine laser with bulk formation of iodine atoms by an electric discharge  

Microsoft Academic Search

A preliminary investigation was made of a chemical oxygen---iodine laser with bulk formation of iodine atoms in an electric discharge. The output energy was comparable with that obtained for a photolysis variant of the laser, but the technical efficiency of the investigated discharge variant was much higher (91%). The pulse power (~100 kW) was approximately three orders of magnitude higher

Nikolai P. Vagin; V. S. Pazyuk; Nikolai N. Yuryshev

1995-01-01

85

Solar-simulator-pumped atomic iodine laser kinetics  

NASA Technical Reports Server (NTRS)

The literature contains broad ranges of disagreement in kinetic data for the atomic iodine laser. A kinetic model of a solar-simulator-pumped iodine laser is used to select those kinetic data consistent with recent laser experiments at the Langley Research Center. Analysis of the solar-simulator-pumped laser experiments resulted in the following estimates of rate coefficients: for alkyl radical (n-C3F7) and atomic iodine (I) recombination, 4.3 x 10 to the 11th power (1.9) + or - cu cm/s; for n-C3F7I stabilized atomic iodine recombination (I + I) 3.7 x 10 to the -32nd power (2.3) + or -1 cm to the 6th power/s; and for molecular iodine (I2) quenching, 3.1 x 10 to the -11th power (1.6) + or - 1 cu cm/s. These rates are consistent with the recent measurements.

Wilson, H. W.; Raju, S.; Shiu, Y. J.

1983-01-01

86

Chemical generation of atomic iodine for the chemical oxygen iodine laser. II. Experimental results  

NASA Astrophysics Data System (ADS)

A new method for the chemical generation of atomic iodine intended for use in a chemical oxygen-iodine laser (COIL) was investigated experimentally. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Effects of the initial ratio of reactants and their mixing in a flow of nitrogen were investigated experimentally and interpreted by means of a computational model for the reaction system. The yield of iodine atoms in the nitrogen flow reached 70-100% under optimum experimental conditions. Gain was observed in preliminary experiments on the chemical generation of atomic iodine in a flow of singlet oxygen.

Špalek, Otomar; Jirásek, Vít.; ?enský, Miroslav; Kodymová, Jarmila; Jakubec, Ivo; Hager, Gordon D.

2002-08-01

87

Systematic diagnostics of a chemical oxygen-iodine laser device  

Microsoft Academic Search

There are two kinds of diagnostics for chemical oxygen-iodine laser (COIL) system, laser device diagnostics and laser beam diagnostics. In this paper, we only discussed systematically the former. We divide them into several diagnostic subsystems such a flow diagnostic, oxygen-iodine flow mixing diagnostic, gain medium diagnostic and resonator diagnostic. In flow diagnostic, we selected some independent and easy-measured physical variables

Xiangwan Du; Jianxiang Wang

1998-01-01

88

Novel concept of electric discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A novel concept of discharge oxygen-iodine laser (DOIL) is presented. The supersonic DOIL includes a discharge singlet oxygen generator (DSOG) and discharge atomic iodine generator (DAIG). The operation of DSOG is based on a fast mixing of hybrid argon plasma jet of DC electric arc and RF discharge with a neutral molecular oxygen stream. The goal of our effort is achievement of DOIL oscillations by this new discharge technique, which should provide the singlet oxygen yields exceeding 30% at the total pressures higher than 10 torr. The DAIG operation is based on a cw/pulse RF discharge dissociation of iodine donors directly inside a laser iodine injector. This method substitutes the classic dissociation of molecular iodine by energy of singlet oxygen, which saves its energy for laser generation and so can increase the laser efficiency. The laser power could be thus enhanced by up to 25% if this method is employed in a chemical oxygen-iodine laser (COIL) operation, and even 3 times in DOIL without increase in the iodine laser pumping by singlet oxygen.

Schmiedberger, J.; Jirásek, V.; Kodymová, J.; Rohlena, K.

2009-08-01

89

ARTICLES: Electron-beam-controlled chemical hydrogen-iodine laser  

Microsoft Academic Search

A study is made of the feasibility of constructing a hydrogen-iodine laser with electron-beam-controlled excitation, emitting as a result of the 2P1\\/2-->2P3\\/2 magnetic-dipole transition in atomic iodine (lambda = 1.315 mu). The necessary iodine atoms are produced in an H2-Ar-I2 mixture as a result of a fast chemical reaction H + I2-->HI + I initiated by an electric discharge. An

Igor'M. Bel'dyugin; Yu P. Vysotskii; A. A. Stepanov; V. A. Shcheglov

1987-01-01

90

Electron-beam-controlled chemical hydrogen–iodine laser  

Microsoft Academic Search

A study is made of the feasibility of constructing a hydrogen–iodine laser with electron-beam-controlled excitation, emitting as a result of the 2P1\\/2?2P3\\/2 magnetic-dipole transition in atomic iodine (? = 1.315 ?). The necessary iodine atoms are produced in an H2–Ar–I2 mixture as a result of a fast chemical reaction H + I2?HI + I initiated by an electric discharge. An

Igor M Beldyugin; Yu P Vysotski?; A A Stepanov; V A Shcheglov

1987-01-01

91

Advances in development of chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The contribution deals with three investigated problems on Chemical Oxygen-Iodine Laser (COIL) and utilization of the results in advanced COIL development and advanced techniques connected with the COIL. These problems are following i) A gain modulation on the laser transition in iodine atom, I(2P1/2)-(2P3/2), by an external magnetic field, and its utilization for the COIL output power stabilization, ii) The evaluation of the Einstein A-coefficient of singlet oxygen, O2(1?g), and utilization of this coefficient in the advanced diagnostics for O2(1?g) determination in a laser pumping, and iii) A development of the advanced COIL using a chemically driven iodine atom delivery system, and a confrontation of advantages of this system with disadvantages of conventional source of atomic iodine via dissociated molecular iodine. Examples of few recent experimental results are presented.

Kodymova, Jarmila

2004-06-01

92

Plasma chemical oxygen-iodine laser: problems of development  

Microsoft Academic Search

Great success has been obtained in the R&D of a chemical oxygen-iodine laser (COIL) operating on the electronic transition of the iodine atom, which gets an excitation from the energy donor -singlet delta oxygen (SDO). The latter is normally produced in a chemical SDO generator using very toxic and dangerous chemicals, which puts a limit for civilian applications of COIL

Andrei A. Ionin; Anatoly P. Napartovich; Nikolai N. Yuryshev

2002-01-01

93

Chemical generation of atomic iodine for chemical oxygen iodine laser. I. Modelling of reaction systems  

NASA Astrophysics Data System (ADS)

The mathematical modelling of reaction systems for chemical generation of atomic iodine is presented. This process is aimed to be applied in the chemical oxygen-iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. In the suggested method, gaseous reactants for I atoms generation are admixed into the COIL primary gas flow containing singlet oxygen. Two reaction systems were proposed, based on the reaction of hydrogen iodide with chemically generated atomic fluorine or chlorine. It was found that the reaction path via Cl atoms better matches the experimental conditions of COIL with a yield of atomic iodine of up to 67%. As a result of modelling, a suitable reaction system and design of experimental arrangement for the effective production of atomic iodine in laser conditions were found.

Jirásek, Vít.; Špalek, Otomar; Kodymová, Jarmila; ?enský, Miroslav

2001-07-01

94

Parameters of an electric-discharge generator of iodine atoms for a chemical oxygen-iodine laser  

Microsoft Academic Search

Laser-induced fluorescence is used for measuring the concentration of iodine molecules at the output of an electric-discharge generator of atomic iodine. Methyl iodide CHI is used as the donor of atomic iodine. The fraction of iodine extracted from CHI in the generator is 50%. The optimal operation regimes are found in which 80%-90% of iodine contained in the output flow

V N Azyazov; M V Vorobev; A I Voronov; Nikolai V Kupryaev; P A Mikheev; N I Ufimtsev

2009-01-01

95

Advances in the RF atomic iodine generator for oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Recent advances in the RF atomic iodine generator for oxygen-iodine lasers are presented. The generator is based on the RF discharge dissociation of a suitable iodine donor immediately before its injection to the flow of singlet oxygen. The discharge is ignited directly in the iodine injector, and the configuration is ready for the laser operation. The dissociation fraction was derived from the atomic iodine number density measured at a presupposed position of laser resonator. The dissociation fraction and the fraction of RF power spent on the dissociation (discharge dissociation efficiency) were measured for the following donors: CH3I, CF3I and HI. A significant improvement of the discharge stability was achieved by increasing the cross-sectional area of the exit injection holes and employing a tangential inlet of working gas into the discharge chamber. The flow rates 0.15 mmol/s and 0.19 mmol/s of produced atomic iodine were achieved using the HI and CF3I, respectively. The atomic iodine number density in the supersonic flow attained 4.22 × 1014 cm-3. The dissociation efficiency was substantially better for HI than for studied organic iodides.

Jirásek, Vít; Schmiedberger, Josef; ?enský, Miroslav; Kodymová, Jarmila

2010-09-01

96

Spatial gain measurements in a chemical oxygen iodine laser (COIL)  

Microsoft Academic Search

The spatial distribution of small signal gain has been investigated on the RADICL device, a supersonic chemical oxygen-iodine laser (COIL). A frequency-stabilized, narrow linewidth diode laser system operating on the F=3?F=4 hyperfine levels of the (2 P1\\/2) to (2P3\\/2) spin-orbit transition in atomic iodine was used as a small signal probe. A peak gain of 1.2%\\/cm was measured along the

R. F. Tate; B. S. Hunt; C. A. Helms; K. A. Kruesdell; G. D. Hager

1995-01-01

97

Evolution of the electric discharge oxygen-iodine laser  

Microsoft Academic Search

Experiments and modeling have led to a continuing evolution of the Electric Oxygen-Iodine Laser (ElectricOIL) system. This continuous wave (cw) laser operating on the 1315 nm transition of atomic iodine is pumped by the production of O2(a) in a radio-frequency (RF) discharge in an O2\\/He\\/NO gas mixture. New discharge geometries have led to improvements in O2(a) production and efficiency. Further,

David L. Carroll; Gabriel F. Benavides; Joseph W. Zimmerman; Brian S. Woodard; Andrew D. Palla; Michael T. Day; Joseph T. Verdeyen; Wayne C. Solomon

2010-01-01

98

Chemical oxygen-iodine laser with atomic iodine generated via Cl or F atoms  

NASA Astrophysics Data System (ADS)

Two alternative chemical methods of atomic iodine generation for a chemical oxygen-iodine laser (COIL) were studied. These methods are based on fast reactions of gaseous hydrogen iodide with chemically produced chlorine and fluorine atoms. Both processes were studied first in small-scale reactors. A yield of atomic iodine in the Cl system and nitrogen (non-reactive) atmosphere exceeded 80%, while in the F system it was only up to 27% related to F2 or 50% related to HI. The process of atomic iodine generation via Cl atoms was employed in operation of the supersonic COIL. A laser power of 430 W at 40 mmol Cl2/s, and the small signal gain up to 0.4%/cm were attained. The proposed methods promise an increase in laser power, easier control of laser operation, and simpler iodine management in comparison with the conventional source of atomic iodine using I2. The experimental results obtained so far with this experimental arrangement did not proved yet increasing COIL chemical efficiency because some process quenching a part of singlet oxygen was indicated. Therefore a modified experimental set-up has been designed and prepared for further investigation.

Spalek, Otomar; Jirasek, Vit; Censky, Miroslav; Kodymova, Jarmila; Jakubec, Ivo; Hager, Gordon D.

2005-03-01

99

Singlet delta oxygen generation for Chemical Oxygen-Iodine Lasers  

Microsoft Academic Search

The development of Chemical Oxygen-Iodine Lasers is based on the generation of singlet delta oxygen. To improve the overall efficiency of these lasers, it is necessary to increase the generator production and yield of singlet delta oxygen at low and high pressure, respectively, for subsonic and supersonic lasers. Furthermore, the water vapor content must be as low as possible. A

E. Georges; A. Mouthon; R. Barraud

1991-01-01

100

Advances in the Development of Chemical Oxygen-iodine Laser  

NASA Astrophysics Data System (ADS)

Results of three problems investigated on a Chemical Oxygen-Iodine Laser (COIL) in our laboratory are presented in connection with the advanced COIL development in the world. These problems concern: i) A gain modulation on the laser transition in iodine atom, I(2P1/2) - (2P3/2), by external magnetic field, and its utilization for a COIL output power stabilization, ii) An evaluation of the Einstein A-coefficient of singlet oxygen, O2(1 g), and its utilization in advanced diagnostics for O2(1? g) determination in COIL operation, iii) A chemically driven iodine atom delivery system for advanced COIL.

Kodymová, Jarmila; Špalek, Otomar; Jirásek, Vít; ?enský, Miroslav

2004-05-01

101

LASERS: A pulsed oxygen --- iodine chemical laser excited by a longitudinal electric discharge  

Microsoft Academic Search

The dependence of the energy parameters of an oxygen --- iodine chemical laser with a bulk generation of iodine atoms in a longitudinal electric discharge on the length of the discharge gap is studied for various discharge energies and voltages and various working mixture compositions (at constant oxygen and iodine pressures). Analyses of the results suggests that temperature effects account

Nikolai P. Vagin; Nikolai N. Yuryshev

2002-01-01

102

Laser fluorescence complex for online iodine-129 and iodine-127 detection in gaseous media using a tunable diode laser  

NASA Astrophysics Data System (ADS)

This letter reports on the development of a laser fluorescence complex for high-sensitivity real-time selective detection of 127I and 129I molecular iodine isotopologues in gaseous media. A diode laser tunable in the range of 631–638?nm is used as an excitation source of molecular iodine fluorescence. Sensitivities of detection of molecular iodine isotopologues and boundary relations for simultaneous detection of 127I and 129I were evaluated. It is shown that practical realization of the methods for the detection of molecular iodine isotopologues using a developed laser fluorescence complex provides an opportunity to control these isotopologues in gaseous technological media formed during the reprocessing of spent nuclear fuel and in the atmospheric air.

Kireev, S. V.; Shnyrev, S. L.; Sobolevsky, I. V.; Kondrashov, A. A.

2015-01-01

103

Scaling of an Electric Discharge Excited Oxygen-Iodine Laser  

Microsoft Academic Search

Electric discharge excited oxygen-iodine laser apparatus has been scaled to increase the electric discharge volume and power, the laser mixture flow rate, and the gain path in the M=3 laser cavity. Specifically, singlet delta oxygen (SDO) generator discharge power has been increased at least up to 3.5 kW, laser mixture flow rate up to 0.5 mole\\/sec, and gain path up

John Bruzzese; Munetake Nishihara; Walter Lempert; J. William Rich; Igor Adamovich

2008-01-01

104

Development of the Chemical Oxygen-Iodine Laser (COIL) with chemical generation of atomic iodine  

NASA Astrophysics Data System (ADS)

This article addresses the development of a Chemical Oxygen-Iodine Laser (COIL) with alternative chemical ways of generating atomic iodine. Injection of atomic iodine as opposed to molecular iodine has the potential to improve the COIL efficiency. This paper describes two chemical methods for generating iodine atoms based on the gas phase reactions of hydrogen/deuterium iodide with fluorine or chlorine atoms, which are also produced chemically. Simplified one-dimensional gas dynamic modeling that describes the stream-wise profiles of species concentrations within both reaction systems is used to gain a theoretical understanding of both reaction systems under COIL conditions. The modeling results are used for the design of an experimental device and the interpretation of experimental data. The first experimental investigation studies the production of iodine atoms produced from reactions of Cl with HI. Atomic iodine yields of 70-100% in nitrogen are obtained, and the gain on the I(2P1/2)-I(2P3/2) transition in a flow of singlet oxygen is measured.

Kodymová, J.; Špalek, O.; Jirásek, V.; ?enský, M.; Hager, G. D.

105

Multikilowatt chemical oxygen-iodine laser with chemical generation of molecular iodine  

NASA Astrophysics Data System (ADS)

A multikilowatt chemical oxygen-iodine laser (COIL) using molecular iodine generated chemically as the iodine source was developed and tested. The COIL, with a gain length of 26.5cm, was energized by a square pipe-array jet singlet oxygen generator (JSOG), with a nozzle bank having a designed Mach number of 2.5. The JSOG, operating without a primary buffer gas, has a much better operation stability during basic hydrogen peroxide pumping circulations. Iodine injectors/nozzles made of polyimide were used. An output power of 7.8kW and a chemical efficiency of 24.5% were achieved with a chlorine flow rate of 353mmole/s.

Zhang, Yuelong; Sang, Fengting; Zhang, Peng; Jin, Yuqi; Fang, Benjie; Zhao, Weili; Chen, Fang; Li, Qingwei; Xu, Mingxiu

2007-07-01

106

Novel concept of electric discharge oxygen-iodine laser  

Microsoft Academic Search

A novel concept of discharge oxygen-iodine laser (DOIL) is presented. The supersonic DOIL includes a discharge singlet oxygen\\u000a generator (DSOG) and discharge atomic iodine generator (DAIG). The operation of DSOG is based on a fast mixing of hybrid argon\\u000a plasma jet of DC electric arc and RF discharge with a neutral molecular oxygen stream. The goal of our effort is achievement

J. Schmiedberger; V. Jirásek; J. Kodymová; K. Rohlena

2009-01-01

107

ELEMENTS OF LASER SETUPS: Parameters of an electric-discharge generator of iodine atoms for a chemical oxygen---iodine laser  

Microsoft Academic Search

Laser-induced fluorescence is used for measuring the concentration of iodine molecules at the output of an electric-discharge generator of atomic iodine. Methyl iodide CH3I is used as the donor of atomic iodine. The fraction of iodine extracted from CH3I in the generator is ~50%. The optimal operation regimes are found in which 80%---90% of iodine contained in the output flow

V. N. Azyazov; M. V. Vorob'ev; A. I. Voronov; Nikolai V. Kupryaev; P. A. Mikheev; N. I. Ufimtsev

2009-01-01

108

LASERS: Highly efficient cw chemical oxygen—iodine laser with transsonic iodine injection and a nitrogen buffer gas  

NASA Astrophysics Data System (ADS)

Methods of increasing the efficiency of low-pressure chemical oxygen—iodine lasers (COILs) with transsonic injection of molecular iodine, in which nitrogen is used as a buffer gas, are studied. A two-layer gas-dynamic model is used for a parametric analysis of physicochemical processes occurring in the transsonic iodine injector and in the COIL resonator, including mixing and generation of radiation. The 3D-RANS computer simulation software is used to study the flow structures resulting from an injection of iodine-containing flow into the transsonic zone of the oxygen nozzle. Experiments with a 10-kW modified laser have resulted in a chemical efficiency of 31.5% for a lasing power of 13.5 kW. The results of experimental studies of the cryosorption COIL exhaust system are presented.

Boreysho, A. S.; Barkan, A. B.; Vasil'ev, D. N.; Evdokimov, I. M.; Savin, A. V.

2005-06-01

109

ARTICLES: Electron-beam-controlled chemical hydrogen-iodine laser  

NASA Astrophysics Data System (ADS)

A study is made of the feasibility of constructing a hydrogen-iodine laser with electron-beam-controlled excitation, emitting as a result of the 2P1/2?2P3/2 magnetic-dipole transition in atomic iodine (? = 1.315 ?). The necessary iodine atoms are produced in an H2-Ar-I2 mixture as a result of a fast chemical reaction H + I2?HI + I initiated by an electric discharge. An analysis of the main processes combined with a calculation of the distribution function of electrons is used in a numerical modeling of such a laser. It is found that the specific input energy required in a hydrogen-laser is fairly high, 250-300 J·liter-1·atm-1, and that there are optimal values of this input energy and of the initial temperature of the mixture.

Bel'dyugin, Igor'M.; Vysotski?, Yu P.; Stepanov, A. A.; Shcheglov, V. A.

1987-02-01

110

Advancement and problems of fullerene-oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The methods of improving the efficiency of a fullerene-oxygen-iodine laser are investigated. In the course of this research, we developed new fullerene coatings that possess better mechanical and radiative hardness, as well as higher efficiency of singlet oxygen generation. We show that, by using these coatings, the energy yield per unit volume of the active medium can be increased to 9 J/l, which is almost two times higher than the previous result. The energy efficiency of the laser can also be increased by a factor of nearly two. At the same time, several problems were revealed that hinder the further improvement of the laser efficiency and its long-term operation with stable parameters of the output radiation. We outline principal approaches to further optimization of the laser design that would help to overcome the negative factors and make it possible to create a fullerene-oxygen-iodine laser with high and stable parameters of the output radiation.

Grenishin, A. S.; Kiselev, V. M.; Kislyakov, I. M.; Pavlova, A. L.; Sosnov, E. N.

2010-01-01

111

A 33% efficient chemical oxygen-iodine laser with supersonic mixing of iodine and oxygen  

NASA Astrophysics Data System (ADS)

We report on a highly efficient supersonic chemical oxygen-iodine laser (COIL), with supersonic mixing of iodine and oxygen. Output power exceeding 0.5 kW with chemical efficiency of ˜33% was obtained in a 5-cm gain length for Cl2 flow rate of 17 mmole/s. A 33% efficiency is the highest reported chemical efficiency of any supersonic COIL. Comparison between different mixing schemes shows that, for supersonic mixing, the output power and chemical efficiency are about 20% higher than for transonic mixing scheme. The optimal conditions for the efficient operation are investigated.

Rybalkin, V.; Katz, A.; Barmashenko, B. D.; Rosenwaks, S.

2003-06-01

112

Spectral properties of iodine cells for laser standards  

NASA Astrophysics Data System (ADS)

The main aim of this work is oriented towards preparation and spectral properties evaluation of optical frequency references for laser standards - molecular iodine cells. These references represent the crucial part of setups for practical realization of the meter unit - highly stable laser standards. Furthermore, not only in the most precise laboratory instruments, but also in less demanding interferometric measuring setups the frequency stabilization of the lasers throught the absorption in suitable media ensure the direct traceability to the fundamental standard of length. A set of absorption cells filled with different amounts of molecular iodine (different saturation pressure point of absorption media) was prepared and an agreement between expected and resulting spectral properties of these cells was observed and evaluated. The usage of borosilicate glass instead of common fused silica as a material for cells bodies represents an approach to simplify the manufacturing technology process and also reduces the overall cell costs. A great care must be taken to control/avoid the risk of absorption media contamination by impurities releasing from the cell walls. We introduce an iodine purity and spectral properties evaluation method based on measurement of linewidth of the hyperfine transitions. The proposed method was used for verification of great iodine purity of manufactured cells by comparison of spectral properties with cells traditionally made of fused silica glass with well known iodine purity. The results confirmed a great potential of proposed approaches.

Hrabina, Jan; Šarbort, Martin; Acef, Ouali; Du Burck, Frédéric; Chiodo, Nicola; Chea, Erick; Holá, Miroslava; ?íp, Ond?ej; Lazar, Josef

2014-12-01

113

Studies of new media radiation induced laser  

NASA Technical Reports Server (NTRS)

Various lasants were investigated especially, 2-iodohepafluoropropane (i-C3F7I) for the direct solar pumped lasers. Optical pumping of iodine laser was achieved using a small flashlamp. Using i-C3F7I as a laser gain medium, threshold inversion density, small signal gain, and laser performance at the elevated temperature were measured. The experimental results and analysis are presented. The iodine laser kinetics of the C3F7I and IBr system were numerically simulated. The concept of a direct solar-pumped laser amplifier using (i-C3F7I) as the laser material was evaluated and several kinetic coefficients for i-C3F7I laser system were reexamined. The results are discussed.

Han, K. S.; Shiu, Y. J.; Raju, S. R.; Hwang, I. H.; Tabibi, B.

1984-01-01

114

Chemical kinetics of discharge-driven oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

Oxygen-iodine lasers that utilize electrical discharges to produce O II(a1?) are currently being developed. The discharge generators differ from those used in chemical oxygen-iodine lasers in that they produce significant amounts of atomic oxygen and traces of ozone. As a consequence of these differences, the chemical kinetics of the discharge laser are markedly different from those of a conventional chemical oxygen-iodine laser (COIL). The reactions of O with iodine include channels that are both beneficial and detrimental to the laser. The beneficial reactions result in the dissociation of I II while the detrimental processes cause direct and indirect removal of I(2P 1/2) (denoted I*, the upper level of the laser). We have examined kinetic processes relevant to the laser through studies of photo-initiated reactions in N IIO/CO II/I II mixtures. The reactions have been monitored using absorption spectroscopy, laser induced fluorescence and time-resolved emission spectroscopy. It has been established that deactivation of I* by O atoms is a critical energy loss process. We have determined a rate constant of (1.2+/-0.1)×10 -11 cm 3 s -1 for this reaction. As part of this effort the branching fraction for the formation of O II(a) from the reaction of O(1D) with N IIO was determined to be 0.38. This result has implications for lasers based on photolysis of O 3/N IIO/I II mixtures and the formation of O II(a) in the upper atmosphere.

Azyazov, Valeriy N.; Kabir, Md. Humayun; Antonov, Ivan O.; Heaven, Michael C.

2007-05-01

115

Generation of atomic iodine via fluorine for chemical oxygen iodine laser  

NASA Astrophysics Data System (ADS)

A method of the chemical generation of atomic iodine for a chemical oxygen-iodine laser (COIL) using atomic fluorine as a reaction intermediate was studied experimentally. This method is based on the reaction between F 2 and NO providing F atoms, and the reaction of F with HI resulting in iodine atoms generation. Atomic iodine was produced with efficiency exceeding 40% relative to initial F 2 flow rate. This efficiency was nearly independent on pressure and total gas flow rate. The F atoms were stable in the reactor up to 2 ms. An optimum ratio of the reactants flow rates was F 2:NO:HI = 1:1:1. A rate constant of the reaction of F 2 with HI was determined. The numerical modelling showed that remaining HI and IF were probably consumed in their mutual reaction. The reaction system was found suitable for employing in a generator of atomic iodine with its subsequent injection into a supersonic nozzle of a COIL.

Jirásek, Vít; Špalek, Otomar; ?enský, Miroslav; Picková, Irena; Kodymová, Jarmila; Jakubec, Ivo

2007-04-01

116

LASERS: A pulsed oxygen — iodine chemical laser excited by a longitudinal electric discharge  

NASA Astrophysics Data System (ADS)

The dependence of the energy parameters of an oxygen — iodine chemical laser with a bulk generation of iodine atoms in a longitudinal electric discharge on the length of the discharge gap is studied for various discharge energies and voltages and various working mixture compositions (at constant oxygen and iodine pressures). Analyses of the results suggests that temperature effects account for a twofold decrease in the specific energy yield for the lasing initiated by a longitudinal electric discharge compared to the photolytic initiation.

Vagin, Nikolai P.; Yuryshev, Nikolai N.

2002-07-01

117

Molecular Iodine Fluorescence Using a Green Helium-Neon Laser  

ERIC Educational Resources Information Center

Excitation of molecular iodine vapor with a green (543.4 nm) helium-neon laser produces a fluorescence spectrum that is well suited for the upper-level undergraduate physical chemistry laboratory. Application of standard evaluation techniques to the spectrum yields ground electronic-state molecular parameters in good agreement with literature…

Williamson, J. Charles

2011-01-01

118

Broadband OPCPA pumped by ultra-narrowband gaseous iodine laser  

NASA Astrophysics Data System (ADS)

Amplification of femtosecond pulses using an ultra-narrowband gaseous pulse laser was demonstrated for the first time. A single-shot sub-nanosecond iodine photodissociation laser with a bandwidth of 20 pm was used as a driver in an allstage OPCPA. An externally triggerable OPO tuned to laser line of 1315.24 nm was used in the front end of the iodine laser. Frequency tripled beam at 438 nm was used to pump parametric amplifiers, LBO and KDP crystals. The signal pulses from a Ti:sapphire laser at the central wavelength of 800 nm with a bandwidth of 70 nm (FWHM) were stretched from 12.5 fs to 250 ps and amplified by a factor of 2×108. The amplified pulses of typical bandwidth of 50 nm were compressed down to 27 fs. The output power of 0.5 TW was achieved. An optimized amplifier chain and addition of a third nonlinear crystal would enable to generate femtosecond pulses of several terawatts. The broadband pulses at 800 nm central wavelength were amplified in the KDP crystal for the first time, due to the suitable wavelength of the pump pulses. Availability of large aperture KDP crystals promises the generation of petawatt beam at kJ iodine laser facilities.

Novák, O.; Tur?i?ová, H.; Divoký, M.; Smrž, M.; Huynh, J.; Straka, P.

2012-02-01

119

Chemical oxygen iodine laser (COIL) technology and development  

NASA Astrophysics Data System (ADS)

In the late 1960's researchers realized that producing a population inversion in a moving medium could be used to generate high-energy laser beams. The first lasers to scale to the 10 kW size with good beam quality were supersonic flows of N2 - CO2, emitting radiation from the CO2 at 10.6 microns. In the 1970's gas dynamic CO2 lasers were scaled to hundreds of kilowatts and engineered into a KC-135 aircraft. This aircraft (The Airborne Laser Laboratory) was used to shoot down Sidewinder AIM-9B missiles in the early 1980"s. During this same time period (1970-1990) hydrogen fluoride and deuterium fluoride lasers were scaled to the MW scale in ground-based facilities. In 1978, the Iodine laser was invented at the Air Force Research Laboratory and scaled to the 100 kW level by the early 1990"s. Since the 60s, the DOD Chemical Laser development efforts have included CO2, CO, DF, HF, and Iodine. Currently, the DOD is developing DF, HF, and Iodine lasers, since CO2 and CO have wavelengths and diffraction limitations which make them less attractive for high energy weapons applications. The current military vision is to use chemical lasers to prove the principles and field ground and air mounted laser systems while attempting to develop weight efficient solid-state lasers at the high power levels for use in future Strategic and Tactical situations. This paper describes the evolution of Chemical Oxygen Iodine Lasers, their selection for use in the Airborne Laser (ABL), and the Advanced Tactical Laser (ATL). COIL was selected for these early applications because of its power scalability, its short wavelength, its atmospheric transmittance, and its excellent beam quality. The advantages and challenges are described, as well as some of the activities to improve magazine depth and logistics supportability. COIL lasers are also potentially applicable to mobile ground based applications, and future space based applications, but challenges exist. In addition, COIL is being considered for civil commercial applications in the US and overseas.

Duff, Edward A.; Truesdell, Keith A.

2004-09-01

120

LASERS: Pulsed chemical oxygen --- iodine laser initiated by a transverse electric discharge  

Microsoft Academic Search

A pulsed chemical oxygen --- iodine laser with a volume production of atomic iodine in a pulsed transverse electric discharge is studied. An increase in the partial oxygen pressure was shown to increase the pulse energy with retention of the pulse duration. At the same time, an increase in the iodide pressure and the discharge energy shortens the pulse duration.

Nikolai P. Vagin; Nikolai N. Yuryshev

2001-01-01

121

Studies of iodine dissociation in the chemical oxygen-iodine laser  

Microsoft Academic Search

The dissociation of I2 molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied experimentally as a function of I2 flow rate. The measurements revealed that the number of consumed O2(1Delta) molecules per dissociated I2 molecule depends on the experimental conditions: it is 4.2 +\\/- 0.4 for typical conditions and I2 densities applied for the operation

V. Rybalkin; A. Katz; K. Waichman; D. Vingurt; Z. Dahan; B. D. Barmashenko; S. Rosenwaks

2007-01-01

122

Mechanism of pulse discharge production of iodine atoms from CF3I molecules for a chemical oxygen–iodine laser  

Microsoft Academic Search

The pulsed chemical oxygen–iodine laser (COIL) development is aimed at many new applications. Pulsed electric discharge is most effective in turning COIL operation into the pulse mode by instant production of iodine atoms. A numerical model is developed for simulations of the pulsed COIL initiated by an electric discharge. The model comprises a system of kinetic equations for neutral and

I V Kochetov; A P Napartovich; N P Vagin; N N Yuryshev

2009-01-01

123

Mechanism of pulse discharge production of iodine atoms from CF3I molecules for a chemical oxygen-iodine laser  

Microsoft Academic Search

The pulsed chemical oxygen-iodine laser (COIL) development is aimed at many new applications. Pulsed electric discharge is most effective in turning COIL operation into the pulse mode by instant production of iodine atoms. A numerical model is developed for simulations of the pulsed COIL initiated by an electric discharge. The model comprises a system of kinetic equations for neutral and

I. V. Kochetov; A. P. Napartovich; N. P. Vagin; N. N. Yuryshev

2009-01-01

124

Frequency tuning of a CW atomic iodine laser via the Zeeman effect  

Microsoft Academic Search

A continuously operating, C3F7I photolytic 1.315-?m atomic iodine laser has been used to make the first precise observations of frequency tuning of an atomic iodine laser by means of the Zeeman effect. Application of a uniform magnetic field to the gain region of the photolytic iodine laser causes the laser to operate at different frequencies as a function of the

M. A. Kelly; J. K. McIver; R. F. Shea; G. D. Hager

1991-01-01

125

Nuclear-driven flashlamp pumping of the atomic iodine laser  

SciTech Connect

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

Miley, G.H.

1992-03-01

126

Simplified chemical oxygen iodine laser (COIL) system model  

Microsoft Academic Search

An end-to-end system model has been developed to model the performance of a rotating disk reactor-based Chemical Oxygen Iodine Laser (COIL) system. The model consists of a system of nonlinear algebraic equations combined into modules by subsystem and is well suited for system trade studies and subsystem data analysis. The model treats the three main components of the COIL system

Peter G. Crowell; David N. Plummer

1993-01-01

127

Development of the electric discharge oxygen-iodine laser  

Microsoft Academic Search

In the hybrid electric discharge Oxygen-Iodine laser (ElectricOIL), the desired O2(a1Delta) is produced using a low-to-medium pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the post-discharge kinetics which are not encountered in a classic purely chemical O2(a1Delta) generation system. Experimental studies over the past six years using electric

David L. Carroll; Joseph T. Verdeyen; Darren M. King; Andrew D. Palla; Julia K. Laystrom; Gabriel F. Benavides; Joseph W. Zimmerman; Brian S. Woodard; Wayne C. Solomon

2007-01-01

128

Development of the electric discharge oxygen-iodine laser  

Microsoft Academic Search

In the hybrid electric discharge Oxygen-Iodine laser (ElectricOIL), the desired O2(a 1 ?) is produced using a low-to-medium pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the post-discharge kinetics which are not encountered in a classic purely chemical O2(a 1 ?) generation system. Experimental studies over the past

David L. Carroll; Joseph T. Verdeyen; Darren M. King; Andrew D. Palla; Julia K. Laystrom; Gabriel F. Benavides; Joseph W. Zimmerman; Brian S. Woodard; Wayne C. Solomon

129

Plasma chemical oxygen-iodine laser: problems of development  

NASA Astrophysics Data System (ADS)

Great success has been obtained in the R&D of a chemical oxygen-iodine laser (COIL) operating on the electronic transition of the iodine atom, which gets an excitation from the energy donor -singlet delta oxygen (SDO). The latter is normally produced in a chemical SDO generator using very toxic and dangerous chemicals, which puts a limit for civilian applications of COIL that is still a very unique apparatus. Totally new non-chemical SDO generator is needed to allow oxygen-iodine laser to achieve its full potential as a non-hazardous efficient source of high-power laser radiation. There was interest in producing SDO in electric discharge plasma since the 50's long before COIL appearing. The idea of using SDO as a donor for iodine laser was formulated in the 70's. However, the injection of iodine molecules into a low- pressure self-sustained discharge did not result in iodine lasing. One of the main factors that could prevent from lasing in many experiments is a rather high threshold yield approximately 15 percent at 300K, which is needed for obtaining an inversion population. An analysis of different attempts of producing SDO in different kinds of electric discharge plasma has been done which demonstrates that high yield at gas pressure of practical interest for modern COIL technology can be obtained only in non-self sustained electric discharge plasma. The reason is that the value of relatively low reduced electrical field strength E/N approximately 1E-16 V.cm2, which is an order of magnitude less than that for the self-sustained discharge, is extremely important for the efficient SDO production. Although different kinds of non-self sustained discharges can be used for SDO production, we got started experiments with e-beam sustained discharge in gas mixtures containing oxygen. High specific input energy up to approximately 3 - 5 kJ/ has been experimentally obtained. Theoretical calculations have been done for different experimental conditions indicating a feasibility of reasonable SDO yield. Experimental and theoretical research of self-sustained electric discharge in SDO produced in a chemical generator, which is very important for getting plasma-chemical kinetic data needed for an estimation of SDO yield, is also discussed.

Ionin, Andrei A.; Napartovich, Anatoly P.; Yuryshev, Nikolai N.

2002-05-01

130

Highly efficient cw chemical oxygen-iodine laser with transsonic iodine injection and a nitrogen buffer gas  

SciTech Connect

Methods of increasing the efficiency of low-pressure chemical oxygen-iodine lasers (COILs) with transsonic injection of molecular iodine, in which nitrogen is used as a buffer gas, are studied. A two-layer gas-dynamic model is used for a parametric analysis of physicochemical processes occurring in the transsonic iodine injector and in the COIL resonator, including mixing and generation of radiation. The 3D-RANS computer simulation software is used to study the flow structures resulting from an injection of iodine-containing flow into the transsonic zone of the oxygen nozzle. Experiments with a 10-kW modified laser have resulted in a chemical efficiency of 31.5% for a lasing power of 13.5 kW. The results of experimental studies of the cryosorption COIL exhaust system are presented. (lasers)

Boreysho, A S; Barkan, A B; Vasil'ev, D N; Evdokimov, I M; Savin, A V [D. F. Ustinov Voenmekh Baltic State Technical University, Laser Systems Ltd., St. Petersburg (Russian Federation)

2005-06-30

131

Systematic development of the electric discharge oxygen-iodine laser  

Microsoft Academic Search

Systematic experiments have led to continued improvements in the hybrid Electric Oxygen-Iodine Laser (ElectricOIL) system that significantly increased the discharge performance, supersonic cavity gain, and laser power output. Experimental investigations of radio-frequency (rf) and pulser-sustainer (ps) discharges in O2\\/He\\/NO mixtures in the pressure range of 10-50 Torr and power range of 0.1-2.0 kW have shown that O2(a1Delta) production is a

David L. Carroll; Gabriel F. Benavides; Joseph W. Zimmerman; Brian S. Woodard; Andrew D. Palla; Joseph T. Verdeyen; Wayne C. Solomon

2008-01-01

132

Overview on the chemical oxygen-iodine laser technology  

NASA Astrophysics Data System (ADS)

The "Chemical Oxygen-Iodine Laser" (COIL) has passed through a tremendous development from the first milliwatt to a multi-kilowatt power, and thus offered a great opportunity for investigations in the COIL technology based on a multidisciplinary science. This overview has been aimed at a demonstration of enormous endeavor of the international COIL community in the last years to bring this laser system soon to the end-users by a focusing on advanced concepts of the hardware design, improvement and scaling-up the existing facilities. The overall COIL technology is considered as a sequence of the coexistent technologies of main laser components with a mutual impact: a technology of the singlet oxygen generator, gasdynamic mixing and expansion nozzle, energy extraction and optical resonator, and the exhaust and pressure recovery system. Advanced concepts of the named technologies based on inherent supporting research disciplines - a computational modeling, kinetic studies and diagnostic techniques - are briefly described. A critical insight into the COIL performance via an energy flow, energy losses, power extraction, and a chemical efficiency of this laser system utilizes the established heuristic phenomenology. The paper ends with a reference to developed projects and suggested potential applications of the chemical oxygen-iodine laser technology.

Kodymová, Jarmila

2007-05-01

133

Development of the electric discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

In the hybrid electric discharge Oxygen-Iodine laser (ElectricOIL), the desired O II(a1?) is produced using a low-to-medium pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the post-discharge kinetics which are not encountered in a classic purely chemical O II(a1?) generation system. Experimental studies over the past six years using electric discharges have demonstrated O II(a) yields greater than 20%, gain, and cw laser power. Several modeling studies have also been performed for ElectricOIL and similar systems. As the development of this type of iodine laser continues, the roles of oxygen atoms and NO/NO II are found to be very significant in both the discharge region and downstream of the discharge region. A series of O II(1?) emission, I* emission, O-atom titrations, gain, and O II(1?) yield, NO II* emission, and laser power measurements have been taken to explore the complex phenomena that are being observed. As the overall system is better understood improvements are being made in laser power and efficiency.

Carroll, David L.; Verdeyen, Joseph T.; King, Darren M.; Palla, Andrew D.; Laystrom, Julia K.; Benavides, Gabriel F.; Zimmerman, Joseph W.; Woodard, Brian S.; Solomon, Wayne C.

2007-05-01

134

Kinetic studies for advanced iodine laser concepts  

NASA Astrophysics Data System (ADS)

Recent studies of the iodine dissociation mechanism for COIL systems have prompted new investigations of the energy transfer kinetics of O2(b1?+). Additional motivation for these studies, and for investigation of the quenching of I* by O atoms, is derived from efforts to build non-chemical singlet oxygen generators. Discharge generators produce relatively high concentrations of O2(b) and O atoms. Dissociations of I2 by the reagent streams from these generators will follow different kinetic pathways than those that are most important when the flow from a chemical generator is used. To improve our understanding of conventional COIL systems, and gain insights concerning the dissociation kinetics that will be relevant for discharge driven COIL devices we have examined the quenching of O2(b) and O2(a) by I2, and the deactivation of I* by atomic oxygen. The primary findings are: (1) Quenching of O2(b) by I2 is fast (5.8x10-11 cm3 s-1) with a branching fraction of 0.4 for the channel O2(b)+I2-->O2(a)+I2. (2) The quantum yield for dissociation of I2 by O2(b) is relatively high (>0.5) and (3) The upper bound for the rate constant for quenching of I* by O atoms is k<2x10-12 cm3 s-1.

Han, Jiande; Komissarov, Anatoly V.; Tinney, Scott P.; Heaven, Michael C.; Davis, Steven J.; Lee, Seonkyung

2005-03-01

135

A pulsed oxygen - iodine chemical laser excited by a longitudinal electric discharge  

Microsoft Academic Search

The dependence of the energy parameters of an oxygen - iodine chemical laser with a bulk generation of iodine atoms in a longitudinal electric discharge on the length of the discharge gap is studied for various discharge energies and voltages and various working mixture compositions (at constant oxygen and iodine pressures). Analyses of the results suggests that temperature effects account

Nikolai P Vagin; Nikolai N Yuryshev

2002-01-01

136

Power enhancement in chemical oxygen-iodine lasers by iodine predissociation via corona/glow discharge  

NASA Astrophysics Data System (ADS)

The gain and power in a supersonic chemical oxygen-iodine laser (COIL) are enhanced by applying dc corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I2 prior to its mixing with O2(?1). The loss of O2(?1) consumed for dissociation is thus reduced, and the consequent dissociation rate downstream of the discharge increases, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.

Katz, A.; Dahan, Z.; Rybalkin, V.; Waichman, K.; Barmashenko, B. D.; Rosenwaks, S.

2007-04-01

137

LASERS: Pulsed chemical oxygen — iodine laser initiated by a transverse electric discharge  

NASA Astrophysics Data System (ADS)

A pulsed chemical oxygen — iodine laser with a volume production of atomic iodine in a pulsed transverse electric discharge is studied. An increase in the partial oxygen pressure was shown to increase the pulse energy with retention of the pulse duration. At the same time, an increase in the iodide pressure and the discharge energy shortens the pulse duration. Pulses with a duration of 6.5 ?s were obtained, which corresponds to a concentration of iodine atoms of 1.8 × 1015 cm-3. This concentration is close to the maximum concentration attained in studies of both cw and pulsed oxygen-iodine lasers. A specific energy output of 0.9 J litre-1 and a specific power of 75 kW litre-1 were obtained. The ways of increasing these parameters were indicated. It was found that SF6 is an efficient buffer gas favouring improvements in the energy pulse parameters.

Vagin, Nikolai P.; Yuryshev, Nikolai N.

2001-02-01

138

ELEMENTS OF LASER SETUPS: Parameters of an electric-discharge generator of iodine atoms for a chemical oxygen—iodine laser  

NASA Astrophysics Data System (ADS)

Laser-induced fluorescence is used for measuring the concentration of iodine molecules at the output of an electric-discharge generator of atomic iodine. Methyl iodide CH3I is used as the donor of atomic iodine. The fraction of iodine extracted from CH3I in the generator is ~50%. The optimal operation regimes are found in which 80%—90% of iodine contained in the output flow of the generator was in the atomic state. This fraction decreased during the iodine transport due to recombination and was 20%—30% at the place where iodine was injected into the oxygen flow. The fraction of the discharge power spent for dissociation was ~3%.

Azyazov, V. N.; Vorob'ev, M. V.; Voronov, A. I.; Kupryaev, Nikolai V.; Mikheev, P. A.; Ufimtsev, N. I.

2009-01-01

139

The research on discharge oxygen iodine laser in Japan  

NASA Astrophysics Data System (ADS)

A decade has passed, since Discharge Oxygen Iodine Laser (DOIL) research started in our laboratory. Singlet delta oxygen production tests were carried out using RF discharge singlet oxygen generator of the first version (DSOG-1) in 1993. The maximum yield of 4.2% was achieved by DSOG-1. Efforts for improving RF-DSOG have been continuously carrying on and DSOG-5 is now under operation. The DSOG-5 consists of a jet nozzle having a diameter of 3 mm, an injector quarts nozzle of 2 mm diameter set inside the jet nozzle at coaxial position and a mixing slit nozzle with the height of 0.2 mm set surrounding the jet nozzle exit. High electric field is laid on inside surface of the jet nozzle by 200 W RF power source. The singlet delta oxygen is produced by energy transfer from Argon plasma which is produced in the jet nozzle. It is important for achieving high yield to have a good mixing of oxygen, blown from the slit nozzle and the quarts nozzle, with the Argon plasma. The yield of 24% was recorded when oxygen gas 110 sccm was mixed with 700 sccm Argon gas at the pressure 0.6 torr and the RF power 196 W. With a new laser system reinforced by a discharge iodine dissociation and a laser gas cooling device, oscillation tests were carried out in conjunction with the DSOG-5. Performance of the system was confirmed by an emission from excited iodine atoms which energy was transferred from the singlet delta oxygen. It is obvious that the new system gives a progress for the DOIL oscillation.

Fujii, Hiroo; Kihara, Yoshihumi; Funakoshi, Ryota; Okamura, Minoru; Schmiedberger, Josef

2004-09-01

140

A multiwatt all gas-phase iodine laser (AGIL)  

NASA Astrophysics Data System (ADS)

The demonstration and characterization of a multiwatt All Gas-phase Iodine Laser (AGIL) are described. A 20-cm subsonic reactor was used to produce NCl(a1?) for a series parametric studies of the I*(2P1/2) - I(2P3/2) small signal gain and extracted power dependence on reactant flow rates and reaction time. A reduction in the flow channel height led to improved performance. The highest measured gain was 4.2 x 10-4 cm-1 and the highest power observed was 31 W.

Manke, Gerald C., II; Cooper, Chris B.; Dass, Shiv C.; Madden, Timothy J.; Hager, Gordon D.

2004-05-01

141

A multiwatt all gas-phase iodine laser (AGIL)  

NASA Astrophysics Data System (ADS)

The demonstration and characterization of a multiwatt All Gas-phase Iodine Laser (AGIL) are described. A 20-cm subsonic reactor was used to produce NCl(a1?) for a series parametric studies of the I*(2P1/2) - I(2P3/2) small signal gain and extracted power dependence on reactant flow rates and reaction time. A reduction in the flow channel height led to improved performance. The highest measured gain was 4.2 x 10-4 cm-1 and the highest power observed was 31 W.

Manke, Gerald C., II; Cooper, Chris B.; Dass, Shiv C.; Madden, Timothy J.; Hager, Gordon D.

2004-09-01

142

Mulitwatt all gas-phase iodine laser (AGIL)  

NASA Astrophysics Data System (ADS)

The demonstration and characterization of a multi-watt All Gas-phase Iodine Laser (AGIL) are described. A 20-cm subsonic reactor was used to produce NCl(a1?) for a series of parametric studies of the I*(2P1/2)-I(2P3/2) small signal gain and extracted power dependence on reactant flow rates and reaction time. The highest measured gain was 2.5x10-4 cm-1 and the highest power observed was 18 W.

Manke, Gerald C., II; Cooper, Chris B.; Dass, Shiv C.; Madden, Timothy J.; Hager, Gordon D.

2003-06-01

143

High-pressure gravity-independent singlet oxygen generator, laser nozzle, and iodine injection system for the chemical oxygen-iodine laser  

Microsoft Academic Search

A novel approach is outlined for a singlet oxygen generator (SOG), a laser minimum length nozzle (MLN), and an iodine injector system for a chemical oxygen-iodine laser (COIL). A unified approach, referred to as a SOG\\/MLN\\/I2 system, is partly based on past experimental work. For instance, the SOG concept stems from sparger technology and a KSY fesibility experiment. A MLN

George Emanuel

2004-01-01

144

Photolysis/Electrical Discharge Initiated Pulsed Chemical Oxygen-Iodine Lasers Using Alkyl Iodides As The Iodine Source  

NASA Astrophysics Data System (ADS)

A photolyzed 02(1?)-CH3I-N2 mixture was made to lase with an output energy of over 160 mJ per pulse. The utilization efficiency of the stored 02(1?) energy attains 12%. The evidence provided by our experiments confirms that the major contribution to the laser energy comes from the energy transferred from 02(1?) to the iodine atom. A comparison between 02(1?)-CH3I-N2 and 02(1?)-CF3I-N2 mixtures suggests that the laser performance is strongly affected by the molecular species of the iodides and the former exceeds the latter in many respects. It is also shown that N2 is as good a buffer gas as Ar in the pulsed chemical oxygen-iodine laser with respect to laser output. The paper also demonstrates for the first time the feasibility of an electrically initiated pulsed oxygen-iodine laser. It is confirmed that the reactions of the oxygen-iodine laser can be efficiently initiated by using low energy electrons. The electrical efficiency is 350 times higher than that obtained with iodide photolysis.

Zhang, Rongyao; Chen, Fang; Song, Xueqin; Xu, Qingzhou; Huan, Changqing; Zhuang, Qi; Zhang, Cunhao

1990-01-01

145

Photolysis/electrical discharge initiated pulsed chemical oxygen-iodine lasers using alkyl iodides as the iodine source  

NASA Astrophysics Data System (ADS)

A photolyzed O2(1-Delta)-CH3I-N2 mixture was made to lase with an output energy of over 160 mJ per pulse. The utilization efficiency of the stored O2(1-Delta) energy attains 12 percent. The evidence provided by these experiments confirms that the major contribution to the laser energy comes from the energy transferred from O2(1-Delta) to the iodine atom. A comparison between O2(1-Delta)-CH3I-N2 and O2(1-Delta)-CF3I-N2 mixtures suggests that the laser performance is strongly affected by the molecular species of the iodides and the former exceeds the latter in many respects. It is also shown that N2 is as good a buffer gas as Ar in the pulsed chemical oxygen-iodine laser with respect to laser output. The paper also demonstrates for the first time the feasibility of an electrically initiated pulsed oxygen-iodine laser. It is confirmed that the reactions of the oxygen-iodine laser can be efficiently initiated by using low energy electrons. The electrical efficiency is 350 times higher than that obtained with iodide photolysis.

Zhang, Rongyao; Chen, Fang; Song, Xueqin; Xu, Qingzhou; Huan, Changqing

1989-06-01

146

Iodine  

MedlinePLUS

... Diatomique, Iode Moléculaire, Iode Mono-atomique, Iode de Povidone, Iode de Sodium, Iodide, Iodized Salt, Iodure, Iodure ... Numéro atomique 53, Periodate de Sodium, Potassium Iodide, Povidone Iodine, Saturated Solution Potassium Iodide, Sel Iodé, Sodium ...

147

Iodine  

MedlinePLUS

... Scientists are studying iodine to understand how it affects health. Here are some examples of what this research has shown. Fetal and infant development Women who are pregnant or breastfeeding need ...

148

Parametric studies of a small-scale supersonic chemical oxygen-iodine laser (COIL)  

Microsoft Academic Search

Parametric studies of the gain and the power of a small scale supersonic chemical oxygen- iodine laser are presented. The laser is of 5 cm long active medium, and utilizes a simple sparger-type O2(1(Delta) ) chemical generator and a medium size pumping system. A grid nozzle is used for iodine injection and supersonic expansion. 45 W of CW laser emission

Salman Rosenwaks; B. D. Barmashenko; A. Elior; E. Lebiush; I. Blyvas

1995-01-01

149

Two-dimensional gain measurements in a chemical oxygen-iodine laser (COIL) device  

Microsoft Academic Search

The spatial distribution of gain has been investigated on the Research Assessment and Device Improvement Chemical Laser, a supersonic chemical oxygen-iodine laser (COIL). A frequency-stabilized, narrow linewidth diode laser system operating on the F equals 3 yields F equals 4 hyperfine levels of the (2P1\\/2) to (2P3\\/2) spin-orbit transition in atomic iodine was used as a small signal probe. A

R. F. Tate; B. Scott Hunt; Gordon D. Hager; Charles A. Helms; Keith A. Truesdell

1995-01-01

150

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

The investigation of stimulated emission causing transitions from the B(1) pi sub u state of sodium to the overlapping 2(1) sigma(+) sub g electronic state has been continued. A new method of estimating the Franck-Condon factors has been developed which instead of fitting the molecular potential curves with Morse functions, estimates the V(r) dependence by interpolation from given potential curves. The results for the sum of the rates from one vibrational level in the upper state to all the levels in the lower state show good agreement with the previous method, implying that curve crossing by stimulated emission due to photons from the oven is an important mechanism in sodium.

Harries, Wynford L.

1988-01-01

151

LASERS: Electrode system for electric-discharge generation of atomic iodine in a repetitively pulsed oxygen --- iodine laser with a large active volume  

Microsoft Academic Search

Possibilities for increasing the active medium volume of a chemical oxygen --- iodine laser (CCOIL) with a pulsed electric-discharge generation of atomic iodine are studied. The reasons are analysed of the low stability of the transverse self-sustained volume discharge in electrode systems with metal cathodes under the conditions of the electric energy input into gas-discharge plasma that are typical for

S. Yu Kazantsev; I. G. Kononov; S. V. Podlesnykh; K. N. Firsov

2010-01-01

152

Pulsed chemical oxygen - iodine laser initiated by a transverse electric discharge  

Microsoft Academic Search

A pulsed chemical oxygen - iodine laser with a volume production of atomic iodine in a pulsed transverse electric discharge is studied. An increase in the partial oxygen pressure was shown to increase the pulse energy with retention of the pulse duration. At the same time, an increase in the iodide pressure and the discharge energy shortens the pulse duration.

Nikolai P Vagin; Nikolai N Yuryshev

2001-01-01

153

Problems of development of oxygen-iodine laser with electric discharge production of singlet delta oxygen  

Microsoft Academic Search

Great success has been obtained in the R&D of a chemical oxygen-iodine laser (COIL) operating on the electronic transition of the iodine atom, which gets an excitation from the energy donor -singlet delta oxygen (SDO). The latter is normally produced in a chemical SDO generator using very toxic and dangerous chemicals, which puts a limit for civilian applications of COIL

Andrei A. Ionin; Anatoly P. Napartovich; Nikolai N. Yuryshev

2002-01-01

154

LASERS: Self-initiating volume discharge in iodides used for producing atomic iodine in pulsed chemical oxygen — iodine lasers  

NASA Astrophysics Data System (ADS)

A volume self-sustained discharge (VSD) in iodides (C3H7I, C4H9I) and in their mixtures with SF6, N2, and O2 in the presence of small-scale inhomogeneities on the cathode surface is shown to develop in the form of a self-initiating volume discharge (SIVD), i.e., a volume discharge without any preionisation including discharge gaps with a strong edge enhancement of the electric field. Additions of SF6 or N2 to the iodides improves the stability and homogeneity of the SIVD, while adding up to 300 % (relative to the partial iodide pressure) of O2 to these mixtures has only an insignificant effect on the discharge stability. The possibility of SIVD initiation was modelled experimentally in a 1.5-L discharge volume. For the C4H9I:O2:SF6=0.083:0.25:0.67 mixture at a pressure of 72 Torr, the specific energy input into the discharge plasma ranged up to 130 J L-1 in this geometry. A conclusion was drawn that the SIVD is promising for the production of atomic iodine in the pulsed and repetitively pulsed operating regimes of a chemical oxygen — iodine laser.

Belevtsev, A. A.; Kazantsev, S. Yu; Saifulin, A. V.; Firsov, K. N.

2003-06-01

155

Studies of iodine dissociation in the chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The dissociation of I II molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied experimentally as a function of I II flow rate. The measurements revealed that the number of consumed O II(1?) molecules per dissociated I II molecule depends on the experimental conditions: it is 4.2 +/- 0.4 for typical conditions and I II densities applied for the operation of the COIL, but increases at lower I II densities. In addition, a new method for dissociating I II prior to its mixing with O II(1?) and thus reducing the loss of O II(1?) is reported. The method is based on applying corona/glow electrical discharge in the transonic section of the secondary flow in the COIL supersonic nozzle. 1.7% of I II is dissociated by the discharge resulting in 70% power enhancement at rather high I II/O II ratio, 1.6%, close to the optimal value (~ 2.5%) for operation of COILs with supersonic mixing.

Rybalkin, V.; Katz, A.; Waichman, K.; Vingurt, D.; Dahan, Z.; Barmashenko, B. D.; Rosenwaks, S.

2007-05-01

156

Gain and continuous-wave laser power enhancement with a secondary discharge to predissociate molecular iodine in an electric oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a 50% enhancement in gain and 38% enhancement in continuous-wave laser power on the 1315nm transition of atomic iodine through the addition of a secondary discharge to predissociate the molecular iodine in an electric oxygen-iodine laser. In the primary discharge the O2(a?1) is produced by a radio-frequency-excited electric discharge sustained in an O2-He-NO gas mixture, and I(P1/22) is then pumped using energy transferred from O2(a?1). A gain of 0.10%cm-1 was obtained and the total laser output power was 6.2W.

Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Carroll, D. L.; Verdeyen, J. T.; Field, T. H.; Palla, A. D.; Solomon, W. C.

2008-01-01

157

Electric discharge oxygen-iodine laser: three decades from the idea to the laser development.  

NASA Astrophysics Data System (ADS)

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.

Ionin, Andrey

2006-10-01

158

Continuous wave operation of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses operation of an electric discharge excited oxygen-iodine laser using a high-pressure, non-self-sustained pulser-sustainer discharge. Small signal gain on the 1315 nm iodine atom transition and the laser output power are measured in the M=3 supersonic cavity downstream of the discharge section. In a 15% O2-85% He mixture, at a discharge pressure of 60 torr and discharge power

A. Hicks; Yu. G. Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich

2006-01-01

159

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments  

Microsoft Academic Search

In an electric discharge oxygen-iodine laser, laser action at 1315 nm on the I(2P1\\/2)-->I(2P3\\/2) transition of atomic iodine is obtained by a near resonant energy transfer from O2(a 1Delta) which is produced using a low-pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the postdischarge kinetics which are not

Andrew D. Palla; David L. Carroll; Joseph T. Verdeyen; Wayne C. Solomon

2006-01-01

160

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments  

Microsoft Academic Search

In an electric discharge oxygen-iodine laser, laser action at 1315 nm on the I(2P1?2)?I(2P3?2) transition of atomic iodine is obtained by a near resonant energy transfer from O2(a 1?) which is produced using a low-pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the postdischarge kinetics which are not

Andrew D. Palla; David L. Carroll; Joseph T. Verdeyen; Wayne C. Solomon

2006-01-01

161

A pulsed oxygen-iodine chemical laser initiated by an electrical discharge  

Microsoft Academic Search

The feasibility of a pulsed oxygen-iodine laser which can be initiated efficiently by low energy electrons is demonstrated for the first time. Electrical initiation was used to make an O2(1Delta)-CH3I-N2 mixture lase with an output energy of 130 mJ. Compared with the photoinitiated oxygen-iodine chemical laser, the efficiency of the electrical initiation is 350 times higher and the initiation device

Rongyao Zhang; Fang Chen; Xueqin Song; Qingzhou Xu; Changqing Huan; Zhuang Qi; Zhang Cunhao

1988-01-01

162

A pulsed oxygen-iodine chemical laser initiated by an electrical discharge  

NASA Astrophysics Data System (ADS)

The feasibility of a pulsed oxygen-iodine laser which can be initiated efficiently by low energy electrons is demonstrated for the first time. Electrical initiation was used to make an O2(1Delta)-CH3I-N2 mixture lase with an output energy of 130 mJ. Compared with the photoinitiated oxygen-iodine chemical laser, the efficiency of the electrical initiation is 350 times higher and the initiation device has a smaller volume.

Zhang, Rongyao; Chen, Fang; Song, Xueqin; Xu, Qingzhou; Huan, Changqing

1988-08-01

163

Continuous wave operation of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses operation of an electric discharge excited oxygen-iodine laser using a high-pressure, non-self-sustained pulser-sustainer discharge. Small signal gain on the 1315 nm iodine atom transition and the laser output power are measured in the M=3 supersonic cavity downstream of the discharge section. In a 15% O2–85% He mixture, at a discharge pressure of 60 torr and discharge power

A. Hicks; Yu. G. Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich

2006-01-01

164

COIL--Chemical Oxygen Iodine Laser: advances in development and applications  

Microsoft Academic Search

Advantageous features of Chemical Oxygen-Iodine Laser (COIL) for laser technologies have increased considerably activities of international COIL communities during past ten years. They have been focused on the advanced concepts of hardware designs of the COIL subsystems, and testing and scaling-up of existing laser facilities. Prospective special applications of COIL technology, both civil and military, have received a significant attention

Jarmila Kodymova

2005-01-01

165

Electric discharge oxygen-iodine laser: three decades from the idea to the laser development  

Microsoft Academic Search

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

Andrey Ionin

2006-01-01

166

The research of Iodine pool pressure of chemical oxygen-iodine laser in non-equilibrium condition and its automatic control system design  

NASA Astrophysics Data System (ADS)

In the working process of chemical oxy-iodigenne laser(COIL), the change of iodine pool pressure is complicated. As a result, it causes some mis-judgements, such as the damage of heater and the leakage of iodine steam. Further more, when the heater electric circuit is in a single working status, and after the heater switch is on or off, there exists a buffer time for the stabilization of iodine pool pressure, which is a relatively long time, and the minimum buffer pressure exceeds to 19 torr . Of course, it increases the preparing time for steady operation of laser, and reduces the quality of laser beam. In this paper, we study the iodine pool pressure of COIL in non-equilibrium condition, and analyze the mutation and the serious buffer phenomenon of iodine steam pressure. At the same time, we design an automatic control system for iodine pool pressure, which consists of five modules, such as data collection, automatic control, manual control, heater electric circuit, and the setting and display of pressure. This system uses two kinds of heater electric circuits, in this way, the serious buffer phenomenon of iodine pool pressure is effectively avoided. As a result, the maximal buffer pressure reduces to 4 torr, this makes sure that the iodine steam pressure is suitable for the operation of COIL, which produces a good condition for the steady operation of laser system and an excellent laser output.

Zhou, Songqing; Qu, Pubo; Ren, Weiyan

2013-05-01

167

Design investigation of solar-powered lasers for space applications  

NASA Technical Reports Server (NTRS)

The feasibility of using solar powered continuous wave (CW) lasers for space power transmission was investigated. Competing conceptual designs are considered. Optical pumping is summarized. Solar pumped Lasant type lasers are outlined. Indirect solar pumped lasers are considered.

1982-01-01

168

Plasma Excited Chemical-Oxygen-Iodine Lasers: Optimizing Injection and Mixing for Positive Gain  

Microsoft Academic Search

Chemical oxygen-iodine lasers achieve oscillation on the ^2P1\\/2->^2P3\\/2 transition of atomic iodine at 1.315 mum by a series of excitation transfers from O2(^1delta). In electrically plasma excited devices (eCOILs), O2(^1delta) is produced in a flowing plasma, typically He\\/O2, at a few to tens of Torr. The iodine is injected into the flow as a He\\/I2 mixture immediately upstream (or in)

Natalia Y. Babaeva; Luis A. Garcia; Ramesh A. Arakoni; Mark J. Kushner

2007-01-01

169

Pulse-periodic chemical oxygen-iodine laser with active medium formation by volumetric electric discharge  

Microsoft Academic Search

The paper describes a study of pulse-periodic operation of a chemical oxygen-iodine laser. The generator in use was of the jet type with high chlorine utilization degree (>=97%). Atomic iodine was released by dissociating methyl-iodide (CH3I) in volumetric electric discharge. Steady lasing was achieved at a repetition rate up to 30 Hz. The emission energy attained per individual pulse in

S. D. Velikanov; V. G. Gorelov; I. V. Gostev; Ye. V. Ireshev; V. V. Kalinovsky; I. A. Komissarov; V. V. Konovalov; I. V. Konovalov; V. N. Mikhalkin; V. D. Nikolaev; I. V. Sevryugin; A. V. Smirnov; R. E. Sobolev; L. N. Shornikov

2007-01-01

170

Recent Work on the Development of an Electric Discharge Oxygen Iodine Laser  

Microsoft Academic Search

Theoretical studies have indicated that sufficient fractions of O2( 1 ?) may be produced in an electrical discharge that will permit lasing of an electric discharge oxygen-iodine laser (ElectriCOIL) system in conjunction with injection of pre-dissociated iodine. Results of those studies along with more recent experimental results show that electric excitation is a very complicated process that must be investigated

D. L. Carroll; J. T. Verdeyen; D. M. King; B. Woodardb; L. Skorskib; W. C. Solomon

171

Recent work on the development of an electric discharge oxygen iodine laser  

Microsoft Academic Search

Theoretical studies have indicated that sufficient fractions of O2 (1Delta) may be produced in an electrical discharge that will permit lasing of an electric discharge oxygen-iodine laser (ElectriCOIL) system in conjunction with injection of pre-dissociated iodine. Results of those studies along with more recent experimental results show that electric excitation is a very complicated process that must be investigated with

David L. Carroll; J. T. Verdeyen; D. M. King; B. Woodard; L. Skorski; J. Zimmerman; W. C. Solomon

2003-01-01

172

Mechanism of pulse discharge production of iodine atoms from CF3I molecules for a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The pulsed chemical oxygen-iodine laser (COIL) development is aimed at many new applications. Pulsed electric discharge is most effective in turning COIL operation into the pulse mode by instant production of iodine atoms. A numerical model is developed for simulations of the pulsed COIL initiated by an 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, dissociation of molecules, electron attachment processes, 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 are compared with experimental laser pulse waveforms. It is concluded that there is satisfactory agreement between theory and the experiment. The prevailing mechanism of iodine atom formation from the CF3I donor in a very complex kinetic system of the COIL medium under pulse discharge conditions, based on their detailed numerical modelling and by comparing these results both with experimental results of other authors and their own experiments, is established. The dominant iodine atom production mechanism for conditions under study is the electron-impact dissociation of CF3I molecules. It was proved that in the conditions of the experiment the secondary chemical reactions with O atoms play an insignificant role.

Kochetov, I. V.; Napartovich, A. P.; Vagin, N. P.; Yuryshev, N. N.

2009-03-01

173

RF plasma jet generator of singlet delta oxygen and RF discharge pre-dissociation of iodine for oxygen-iodine laser at lowered temperature  

NASA Astrophysics Data System (ADS)

A new RF plasma jet generator (DSOG-5) of singlet oxygen has been developed for use in an oxygen-iodine laser. The plasma jet was produced in Al nozzles, which were fed by the radio-frequency (100 MHz) power of up to 200 W. The usual mode of operation was an energy transfer from Ar plasma jet to a neutral O2 gas stream. The yield of singlet delta oxygen was up to 24%. Iodine molecules were dissociated by 200 MHz RF discharge with the power of 60 W prior to injection into the mixing zone of laser. The pre-dissociation enhancement was up to 22% of iodine spontaneous emission intensity. Both the DSOG-5 and the RF iodine pre-dissociation were tested in laser experiments in a transverse flow Discharge Oxygen-Iodine Laser (DOIL). The effluent of DSOG-5 was cooled by liquid nitrogen to temperatures in the range 120-300 K. There was a temperature dependent loss of singlet delta oxygen on the walls. The singlet delta oxygen yield and the atomic iodine luminescence at the wavelength of 1315 nm were measured. The highest luminescence was achieved at pressures of ~1 Torr with the yield of 10-20%. Laser oscillations have not been achieved.

Schmiedberger, Josef; Fujii, Hiroo

2005-03-01

174

Computational fluid dynamics methodologies for simulation of chemical oxygen-iodine laser flowfields  

Microsoft Academic Search

Simulation of chemical lasers such as the chemical oxygen-iodine laser (COIL) is of timely interest due to the recent acceleration of the airborne laser military research program and ongoing commercial development programs. As a part of these efforts, a 3-D COIL simulation model was developed based on the Computational Fluid Dynamics (CFD) code GASP which solves the conservative, finite-volume formulation

Timothy John Madden

1997-01-01

175

Intracavity iodine cell spectroscopy with an extended-cavity laser diode around 633 nm  

Microsoft Academic Search

The purpose of the work described was to develop a tunable laser diode which is as easy to use as a He-Ne laser stabilized on iodine. The particularity of this experiment is the use of I2 cell placed inside the extended cavity laser (ECL). The experimental set-up mounted takes the form of a lambdameter which gives the wavelength to one

Alain Zarka; Jean-Marie Chartier; J. Aman; E. Jaatinen

1997-01-01

176

Photolysis\\/electrical discharge initiated pulsed chemical oxygen-iodine lasers using alkyl iodides as the iodine source  

Microsoft Academic Search

A photolyzed O2(1-Delta)-CH3I-N2 mixture was made to lase with an output energy of over 160 mJ per pulse. The utilization efficiency of the stored O2(1-Delta) energy attains 12 percent. The evidence provided by these experiments confirms that the major contribution to the laser energy comes from the energy transferred from O2(1-Delta) to the iodine atom. A comparison between O2(1-Delta)-CH3I-N2 and

Rongyao Zhang; Fang Chen; Xueqin Song; Qingzhou Xu; Changqing Huan

1989-01-01

177

High-pressure gravity-independent singlet oxygen generator, laser nozzle, and iodine injection system for the chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A novel approach is outlined for a singlet oxygen generator (SOG), a laser minimum length nozzle (MLN), and an iodine injector system for a chemical oxygen-iodine laser (COIL). A unified approach, referred to as a SOG/MLN/I2 system, is partly based on past experimental work. For instance, the SOG concept stems from sparger technology and a KSY fesibility experiment. A MLN with a curved sonic line is used for the laser nozzle, and slender struts are used for the injection, in the downstream direction, of iodine/helium vapor. The heated struts are located downstream of the nozzle's throat. The engineering logic behind the approach is discussed; it has a diversity of potential system benefits relative to current technology. These include a compact, scalable laser that can operate in space. The SOG operates at a significantly higher pressure with a high O2(1?) yield. In addition, basic hydrogen peroxide reconditioning is not required, a water vapor removal system is not required, and diluent may be unnecessary, although useful for pressure recovery. The impact on a COIL system in terms of power, efficiency, and pressure recovery is briefly assessed.

Emanuel, George

2004-09-01

178

Gain and continuous-wave laser oscillation on the 1315 nm atomic iodine transition pumped by an air-helium electric discharge  

E-print Network

American Institute of Physics. DOI: 10.1063/1.2957678 The classical chemical oxygen iodine laser COIL re investigations into an electrically driven oxygen-iodine laser ElectricOIL that was demonstrated by Carroll et alGain and continuous-wave laser oscillation on the 1315 nm atomic iodine transition pumped by an air

Carroll, David L.

179

Efficient chemical oxygen-iodine laser powered by a centrifugal bubble singlet oxygen generator  

NASA Astrophysics Data System (ADS)

Efficient production of singlet delta oxygen in a bubble singlet oxygen generator (BSOG) under the influence of centrifugal acceleration, 136g, has been obtained. An output power of 770W with chemical efficiency of 25.6% has been achieved in a small-scale, supersonic chemical oxygen-iodine laser supplied by the centrifugal BSOG. The ratio of the output power to the basic hydrogen peroxide volumetric flow rate was 4.3KJ/liter. Efficient chemical oxygen-iodine laser (COIL) operation with the centrifugal BSOG demonstrates the potential for mobile COIL applications.

Nikolaev, V. D.; Svistun, M. I.; Zagidullin, M. V.; Hager, G. D.

2005-06-01

180

Feasibility of an iodine gas laser pumped by concentrated terrestrial solar radiation  

SciTech Connect

The present work demonstrates the feasibility of a t-C{sub 4}F{sub 9}I iodine gas laser pumped by concentrated terrestrial solar radiation. Iodine gas lasers have advantages when compared to solid-state systems. They pump at low concentration ({approximately}100 suns, as compared to 45,000 suns for the most efficient solid-state lasers; Cooke, 1992), and thus do not require expensive, optical-grade concentration systems. The lasant medium (iodine gas) is easily cooled by flowing the lasant medium, while solid-state lasers require complicated cooling apparatus to avoid crystal fracture from thermal gradients. Finally, a gas laser is easily upsized, as the iodine gas will expand to fill any oscillation cavity. Solid-state lasers are limited by the size of the crystal that can be grown and cooled, and the higher efficiency comes at the cost of the very high solar concentration requirements. The iodine gas under consideration has a smaller overlap with the terrestrial solar spectrum than solid state lasers, and therefore has a lower efficiency. However, comparison of relative efficiencies should also include cost estimates of highly specialized optical equipment (such as sapphire CPC`s), cooling requirements (liquid nitrogen baths), and losses due to blockage of the chopper wheel. Such simplistic comparisons as ratio of power out to solar power in are misleading, as they contain the implicit assumption that solar energy must be purchased, as are fossil fuels. In reality, the solar energy is free, and the true expense is the manufacture and degree of sophistication required of the solar radiation reflection system, and the cooling system.

Terry, C.K.; Peterson, J.E.; Goswami, D.Y. [Univ. of Florida, Gainesville, FL (United States). Dept. of Mechanical Engineering

1996-05-01

181

Pulse-periodic chemical oxygen-iodine laser with active medium formation by volumetric electric discharge  

NASA Astrophysics Data System (ADS)

The paper describes a study of pulse-periodic operation of a chemical oxygen-iodine laser. The generator in use was of the jet type with high chlorine utilization degree (>=97%). Atomic iodine was released by dissociating methyl-iodide (CH 3I) in volumetric electric discharge. Steady lasing was achieved at a repetition rate up to 30 Hz. The emission energy attained per individual pulse in a train was 1.1 J at a pulse energy repeatability of (3÷5) % and a specific energy extraction from the active medium of 1.7 J/L. The lasing pulse duration depended on the concentration of methyl-iodide and the energy deposited into discharge. The minimal half-height duration of pulses was achieved as 10 ?m at a concentration of atomic iodine in the laser cavity ~1*10 15 cm -3.

Velikanov, S. D.; Gorelov, V. G.; Gostev, I. V.; Ireshev, Ye. V.; Kalinovsky, V. V.; Komissarov, I. A.; Konovalov, V. V.; Konovalov, I. V.; Mikhalkin, V. N.; Nikolaev, V. D.; Sevryugin, I. V.; Smirnov, A. V.; Sobolev, R. E.; Shornikov, L. N.

2007-05-01

182

Numerical study of He/CF3I pulsed discharge used to produce iodine atom in chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The pulsed discharge for producing iodine atoms from the alkyl and perfluoroalky iodides (CH3I, CF3I, etc.) is the most efficient method for achieving the pulse operating mode of a chemical oxygen-iodine laser. In this paper, a one-dimensional fluid model is developed to study the characteristics of pulsed discharge in CF3I-He mixture. By solving continuity equation, momentum equation, Poisson equation, Boltzmann equation, and an electric circuit equation, the temporal evolution of discharge current density and various discharge products, especially the atomic iodine, are investigated. The dependence of iodine atom density on discharge parameters is also studied. The results show that iodine atom density increases with the pulsed width and pulsed voltage amplitude. The mixture ratio of CF3I and helium plays a more significant role in iodine atom production. For a constant voltage amplitude, there exists an optimal mixture ratio under which the maximum iodine atom concentration is achieved. The bigger the applied voltage amplitude is, the higher partial pressure of CF3I is needed to obtain the maximum iodine atom concentration.

Zhang, Jiao; Wang, Yanhui; Duo, Liping; Li, Guofu; Wang, Dezhen

2013-04-01

183

Numerical study of He/CF{sub 3}I pulsed discharge used to produce iodine atom in chemical oxygen-iodine laser  

SciTech Connect

The pulsed discharge for producing iodine atoms from the alkyl and perfluoroalky iodides (CH{sub 3}I, CF{sub 3}I, etc.) is the most efficient method for achieving the pulse operating mode of a chemical oxygen-iodine laser. In this paper, a one-dimensional fluid model is developed to study the characteristics of pulsed discharge in CF{sub 3}I-He mixture. By solving continuity equation, momentum equation, Poisson equation, Boltzmann equation, and an electric circuit equation, the temporal evolution of discharge current density and various discharge products, especially the atomic iodine, are investigated. The dependence of iodine atom density on discharge parameters is also studied. The results show that iodine atom density increases with the pulsed width and pulsed voltage amplitude. The mixture ratio of CF{sub 3}I and helium plays a more significant role in iodine atom production. For a constant voltage amplitude, there exists an optimal mixture ratio under which the maximum iodine atom concentration is achieved. The bigger the applied voltage amplitude is, the higher partial pressure of CF{sub 3}I is needed to obtain the maximum iodine atom concentration.

Zhang Jiao; Wang Yanhui; Wang Dezhen [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); Duo Liping; Li Guofu [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116024 (China)

2013-04-15

184

Numerical simulation of the mixing kinetics of an iodine-containing flow and the oxygen flow excited in the electric-discharge oxygen-iodine laser  

Microsoft Academic Search

A parametric analysis has been carried out to discover how the concentration of atomic oxygen in the O2: O2 (1?g): O flow and the degree of predissociation and concentration of molecular iodine in the I2: He mixture affect the temperature regime and the formation of the inverse population at the atomic iodine laser transition\\u000a at elevated pressures of P =

A. A. Chukalovsky; K. S. Klopovsky; T. V. Rakhimova

2008-01-01

185

Electrode system for electric-discharge generation of atomic iodine in a repetitively pulsed oxygen - iodine laser with a large active volume  

Microsoft Academic Search

Possibilities for increasing the active medium volume of a chemical oxygen - iodine laser (CCOIL) with a pulsed electric-discharge generation of atomic iodine are studied. The reasons are analysed of the low stability of the transverse self-sustained volume discharge in electrode systems with metal cathodes under the conditions of the electric energy input into gas-discharge plasma that are typical for

S Yu Kazantsev; I G Kononov; S V Podlesnykh; K N Firsov

2010-01-01

186

Electrode system for electric-discharge generation of atomic iodine in a repetitively pulsed oxygen — iodine laser with a large active volume  

Microsoft Academic Search

Possibilities for increasing the active medium volume of a chemical oxygen — iodine laser (CCOIL) with a pulsed electric-discharge generation of atomic iodine are studied. The reasons are analysed of the low stability of the transverse self-sustained volume discharge in electrode systems with metal cathodes under the conditions of the electric energy input into gas-discharge plasma that are typical for

S Yu Kazantsev; I G Kononov; S V Podlesnykh; K N Firsov

2010-01-01

187

Experimental Effects of Atomic Oxygen on the Development of an Electric Discharge Oxygen Iodine Laser  

Microsoft Academic Search

As the development of the electric discharge iodine laser continues, the role of oxygen atoms downstream of the discharge region was found to be very significant. One of the largest uncertainties is the rate of quenching of I* by O atoms. We have taken a series of measurements of O 2 ( 1 ?) emission, I* emission, O-atom titrations, gain\\/absorption,

D. L. Carroll; J. T. Verdeyen; D. M. King; J. W. Zimmerman; J. K. Laystrom

188

LASERS: Electrode system for electric-discharge generation of atomic iodine in a repetitively pulsed oxygen — iodine laser with a large active volume  

NASA Astrophysics Data System (ADS)

Possibilities for increasing the active medium volume of a chemical oxygen — iodine laser (CCOIL) with a pulsed electric-discharge generation of atomic iodine are studied. The reasons are analysed of the low stability of the transverse self-sustained volume discharge in electrode systems with metal cathodes under the conditions of the electric energy input into gas-discharge plasma that are typical for CCOILs: low pressure of mixtures containing a strongly electronegative component, low voltage of discharge burning, low specific energy depositions, and long duration of the current pulse. An efficient electrode system is elaborated with the cathode based on an anisotropically-resistive material, which resulted in a stable discharge in the mixtures of iodide (CH3I, n-C3H7I, C2H5I) with oxygen and nitrogen at the specific energy depositions of ~5 J L-1, pressures of 10 — 25 Torr, and mixture volume of 2.5 L.

Kazantsev, S. Yu; Kononov, I. G.; Podlesnykh, S. V.; Firsov, K. N.

2010-08-01

189

Theoretical and experimental studies of the all gas-phase iodine laser  

NASA Astrophysics Data System (ADS)

All gas-phase iodine laser (AGIL) powered by the decomposition of nitrogen trichloride (NCl3) is studied. This reaction scheme uses commonly available reagents and reaction paths are milder than the previously studied azide-based AGIL. Theoretical studies revealed the necessary operational conditions for achieving positive gain. An apparatus is made based on the results of the theoretical works. Positive gain at iodine I(2 P 1/2)-I(2 P 3/2) transition is observed for the first time.

Endo, M.; Nakamura, T.; Masuda, T.; Uchiyama, T.

2009-09-01

190

Effects of chemical kinetics of the performance of the atomic iodine laser system  

NASA Astrophysics Data System (ADS)

Model calculations show that chemical reactions which take place in the active medium of a photolytically pumped iodine laser limit the efficiency with which pump photons are utilized and convert significant amounts of the starting material RI to the unwanted by-products R2 and I2. Laser- and RF-discharge-based methods for regenerating starting materials from by-products are evaluated experimentally. For economical operation of large iodine laser systems, CF3I is presently the best starting material, and a pulsed RF-discharge technique is presently the best one for chemical regeneration. The absorbed energy required to regenerate one CF3I molecule using pulsed RF-discharge techniques is 5.8 eV.

Fisk, G. A.; Truby, F. K.

1980-01-01

191

Continuous wave operation of a non-self-sustained electric discharge pumped oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

This letter discusses operation of an electric discharge excited oxygen-iodine laser using a high-pressure, non-self-sustained pulser-sustainer discharge. Small signal gain on the 1315nm iodine atom transition and the laser output power are measured in the M =3 supersonic cavity downstream of the discharge section. In a 15% O2-85% He mixture, at a discharge pressure of 60torr and discharge power of 1.5kW, the highest gain measured in the M =3 cavity is 0.022%/cm, at the flow temperature of T =100±10K. At these conditions, the laser output power is 0.28W.

Hicks, A.; Utkin, Yu. G.; Lempert, W. R.; Rich, J. W.; Adamovich, I. V.

2006-12-01

192

An all gas-phase iodine laser based on NCl3 reaction system  

NASA Astrophysics Data System (ADS)

Theoretical and experimental studies of the amine-based all gas-phase iodine laser (AGIL) are conducted. The numerical simulation code is a detailed one-dimensional, multiple-leaky-stream-tubes kinetics code combined with all the known rate equations to date. Using this code, we find that the key reactions to achieve positive gain are the deactivation reaction of excited iodine atoms by chlorine atoms and the self annihilation reactions of NCl(1?). The order of the injection nozzles is crucial to suppress these reactions. Following the calculations, we fabricate a flow reactor apparatus and demonstrate laser action for the 2P1/2-2P3/2 transition of iodine atom pumped by energy transfer from NCl(1?) produced by a set of amine-based, all gas-phase chemical reactions. Continuous-wave laser output of 50 mW with 40% duty factor is obtained from a stable optical resonator consisting of two 99.99% reflective mirrors. The observed laser characteristics are reasonably explained by numerical calculations. To our knowledge, this is the first achievement of amine-based AGIL oscillation.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2010-02-01

193

Chemical oxygen iodine laser (COIL) technology and development  

Microsoft Academic Search

In the late 1960's researchers realized that producing a population inversion in a moving medium could be used to generate high-energy laser beams. The first lasers to scale to the 10 kW size with good beam quality were supersonic flows of N2 - CO2, emitting radiation from the CO2 at 10.6 microns. In the 1970's gas dynamic CO2 lasers were

Edward A. Duff; Keith A. Truesdell

2004-01-01

194

Parametric study of an efficient supersonic chemical oxygen-iodine laser\\/jet generator system operating without buffer gas  

Microsoft Academic Search

A detailed experimental study of an efficient supersonic chemical oxygen-iodine laser is presented. The laser is energized by a jet-type singlet oxygen generator, operated without primary buffer gas and applies simple nozzle geometry and transonic mixing of iodine and oxygen. Output power of 190 W with chemical efficiency of 18% was obtained in a 5-cm gain length for Cl2 flow

D. Furman; B. D. Barmashenko; S. Rosenwaks

1998-01-01

195

40 IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 36, NO. 1, JANUARY 2000 High-Performance Chemical OxygenIodine Laser  

E-print Network

­iodine laser (COIL), the Ver- tiCOIL device, was transferred from the Air Force Research Laboratory (AFRL-power VertiCOIL laser was measured with nitrogen diluent. New nozzle designs were investigated and implemented in qualitative agreement with the system design predictions of the Blaze II chemical laser model. Three

Carroll, David L.

196

Improvement in Suppression of Pulsed Nd:YAG Laser Light With Iodine Absorption Cells for Filtered Rayleigh Scattering Measurements  

NASA Technical Reports Server (NTRS)

Filtered Rayleigh scattering using iodine absorption cells is an effective technique for obtaining density, temperature, and velocity measurements in high speed confined flows. By tuning a single frequency laser to a strong iodine absorption line, stray scattered laser light can be greatly suppressed. For example, the minimum transmission predicted by an iodine absorption model calculation is less than 10(exp -5) at the 18788.44/cm line using a 200 mm absorption cell containing iodine vapor at 0.46 T. Measurements obtained by other researches using a CW Nd:YAG laser agree with the model calculations. However, measurements made by us and by others using Q-switched, injection-seeded, frequency doubled Nd:YAG lasers only show minimum transmission of about 3 x 10(exp -3). This greatly reduces the applicability of the filtered Rayleigh scattering technique using these lasers in experiments having large amounts of stray scattered laser light. The purposes of the present study are to characterize the spectrum of the excess light transmitted by the iodine cell and to make changes to the laser to reduce the transmitted laser light. Transmission data as a function of laser frequency for the iodine absorption line at 18788.44/cm are presented. A planar mirror Fabry-Perot interferometer was used to characterize the frequency spectrum of the light passed through the cell. Measurements taken with the laser tuned to the center of the iodine absorption line show the light transmitted through the iodine cell to have a component with a bandwidth of about 40 GHz. This is probably caused by other modes in the laser that exist in spite of the single frequency injection beam. A second broadband component was also observed, possibly caused by the laser flash lamps or by fluorescence. An intracavity etalon was installed in the laser oscillator cavity to suppress the 40 GHz component. Measurements taken with the etalon tuned to the injection frequency showed a reduction in the transmitted laser light. This improvement allows the iodine cell to block significantly more of the stray laser light in filtered Rayleigh scattering experiments. Examples are given of filtered Rayleigh scattering measurements showing the effect of the etalon on measurements taken in a Mach 3 flow in the NASA Lewis 4 inch by 10 inch supersonic wind tunnel.

Seasholtz, Richard G.; Buggele, Alvin E

1997-01-01

197

Nuclear-driven flashlamp pumping of the atomic iodine laser. Final report  

SciTech Connect

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

Miley, G.H.

1992-03-01

198

Experimental effects of atomic oxygen on the development of an electric discharge oxygen iodine laser  

Microsoft Academic Search

As the development of the electric discharge iodine laser continues, the role of oxygen atoms downstream of the discharge region was found to be very significant. One of the largest uncertainties is the rate of the quenching of I* by O atoms. We have taken a series of measurements of O2(1Delta) emission, I* emission, O-atom titrations, gain\\/absorption, and O2(1Delta) yield

David L. Carroll; Joseph T. Verdeyen; Darren M. King; J. W. Zimmerman; J. K. Laystrom; B. S. Woodard; G. F. Benavides; K. Kittell; Wayne C. Solomon

2005-01-01

199

Singlet oxygen generator for a solar powered chemically pumped iodine laser. Final Report  

Microsoft Academic Search

The potential of solid phase endoperoxides as a means to produce single-delta oxygen in the gas phase in concentrations useful to chemical oxygen-iodine lasers was investigated. The 1,4 - endoperoxide of ethyl 3- (4-methyl - 1-naphthyl) propanoate was deposited over an indium-oxide layer on a glass plate. Single-delta oxygen was released from the endoperoxide upon heating the organic film by

Busch

1984-01-01

200

Active medium gain study of electric-discharge oxygen-iodine laser  

Microsoft Academic Search

The paper reports on experimental studies of the active medium gain in supersonic electric-discharge oxygen-iodine laser (DOIL) based on traveling mw discharge. The measurements have included: absolute concentration, yield, and energy efficiency of production of SO in pure oxygen and oxygen-helium mixes at an oxygen partial pressure 3 to 15 Torr. For the gas flow to get rid of atomic

Yuriy Kolobyanin; Yuriy Adamenkov; Boris Vyskubenko; Leonid Goryachev; Sergey Ilyin; Anatoliy Kalashnik; Tatiana Rakhimova; Georgiy Rogozhnikov

2007-01-01

201

Characteristics in Dynamics and Power Output of the Iodine Laser Using Iodotrifluoromethane Molecule  

Microsoft Academic Search

The atomic iodine laser with approximate power of 60KW, operating at the wavelength 1.32 (mu)m by I(5('2)P(, 1\\/2)) -- I(5('2)P(,3\\/2)) transition, is investigated experimentally. The optical pumping using argon flash with maximum stored electric energy of 450 joule is used to induce the photolysis of CF(,3)I molecules, and the pulsed electric discharge (0.25 (mu)s duration) through the modified Rogowski electrode

Min Hee Lee

1979-01-01

202

Electric generators of singlet delta oxygen for an oxygen-iodine laser  

Microsoft Academic Search

Experimental and theoretical research into electric generators of singlet delta oxygen (SDO) for an oxygen-iodine laser made\\u000a at the Lebedev Physics Institute and TRINITI is discussed. Breakdown and current-voltage characteristics of self-sustained\\u000a electric discharge in SDO were studied both experimentally and theoretically, indicating that SDO and pure oxygen have quite\\u000a different electric features. The electric properties and spectroscopy of an

A. A. Ionin; A. P. Napartovich; N. N. Yuryshev

2006-01-01

203

Demonstration of an iodine laser pumped by an air–helium electric discharge  

Microsoft Academic Search

Herein the authors report on the demonstration of gain and a continuous-wave laser on the 1315 nm transition of atomic iodine using the energy transferred to I(2P1\\/2) from O2(a 1?) produced by both radio-frequency and microwave electric discharges sustained in a dry air–He–NO gas mixture. Active oxygen and nitrogen species were observed downstream of the discharge region. Downstream of the

B. S. Woodard; J. W. Zimmerman; G. F. Benavides; D. L. Carroll; J. T. Verdeyen; A D Palla; T H Field; W C Solomon; S Lee; W T Rawlins; S J Davis

2010-01-01

204

New concepts of the chemistry of electric-discharge oxygen-iodine lasers  

Microsoft Academic Search

The chemistry of electric discharge driven oxygen iodine lasers (EOIL) has long been believed to have O2(a1▵g) as the sole energy carrier for excitation of the lasing state I(2P1\\/2), and O(3P) as the primary quencher of this state. In many sets of experimental measurements over a wide range of conditions, we have observed persistent evidence to the contrary. In this

Wilson T. Rawlins; Seonkyung Lee; Adam J. Hicks; Ian M. Konen; David B. Oakes; Emily P. Plumb; Steven J. Davis

2011-01-01

205

Investigation of Axially Flowing He\\/O2 Plasmas for Oxygen-Iodine Lasers  

Microsoft Academic Search

Current trends in pumping chemical oxygen-iodine lasers (COIL) involve producing the O_2(^1Delta ) donor in axially flowing rf or pulsed electric discharges, thereby circumventing the hazards and complexity of conventional liquid-phase O_2(^1Delta ) production. Previous global-plug-flow modeling focused on developing reaction mechanisms and determining the specific energy deposition required to achieve high O_2(^1Delta ) yields. Recent experimental efforts have achieved

D. Shane Stafford; Mark J. Kushner

2004-01-01

206

Pulsed oxygen-iodine chemical laser initiated by an electrical discharge  

SciTech Connect

This paper demonstrates for the first time the feasibility of an electrically initiated, pulsed oxygen-iodine laser which can be initiated efficiently by low energy electrons. By electrical initiation, an O/sub 2/(/sup 1/..delta..)--CH/sub 3/I--N/sub 2/ mixture has been made to lase with an output energy of 130 mJ. The efficiency of the electrical initiation is 350 times higher than that obtained with photo-initiation.

Zhang Rongyao; Chen Fang; Song Xueqin; Xu Qingzhou; Huan Changqing; Zhuang Qi; Zhang Cunhao

1988-08-01

207

Problems of development of oxygen-iodine laser with electric discharge production of singlet delta oxygen  

NASA Astrophysics Data System (ADS)

Great success has been obtained in the R&D of a chemical oxygen-iodine laser (COIL) operating on the electronic transition of the iodine atom, which gets an excitation from the energy donor -singlet delta oxygen (SDO). The latter is normally produced in a chemical SDO generator using very toxic and dangerous chemicals, which puts a limit for civilian applications of COIL that is still a very unique apparatus. Totally new non-chemical SDO generator is needed to allow oxygen-iodine laser to achieve its full potential as a non-hazardous efficient source of high-power laser radiation. There was interest in producing SDO in electric discharge plasma since the 50's long before COIL appearing. The idea of using SDO as a donor for iodine laser was formulated in the 70's. However, the injection of iodine molecules into a low- pressure self-sustained discharge did not result in iodine lasing. One of the main factors that could prevent from lasing in many experiments is a rather high threshold yield ~15% at 300K, which is needed for obtaining an inversion population. An analysis of different attempts of producing SDO in different kinds of electric discharge plasma has been done which demonstrates that high yield at gas pressure of practical interest (p > 10 Torr) for modern COIL technology can be obtained only in non-self sustained electric discharge plasma. The reason is that the value of relatively low reduced electrical field strength E/N ~10-16 V.cm2, which is an order of magnitude less than that for the self-sustained discharge, is extremely important for the efficient SDO production. Although different kinds of non-self sustained discharges can be used for SDO production, we got started experiments with e-beam sustained discharge in gas mixtures containing oxygen. High specific input energy up to ~3 - 5 kJ/l. atm [O2] has been experimentally obtained. Theoretical calculations have been done for different experimental conditions indicating a feasibility of reasonable SDO yield. Experimental and theoretical research of self-sustained electric discharge in SDO produced in a chemical generator, which is very important for getting plasma-chemical kinetic data needed for an estimation of SDO yield, is also discussed.

Ionin, Andrei A.; Napartovich, Anatoly P.; Yuryshev, Nikolai N.

2002-09-01

208

O2(^1delta) Production and Oxygen-Iodine Kinetics in Flowing Afterglows for Electrically Excited Chemical-Oxygen-Iodine Lasers  

Microsoft Academic Search

Chemical oxygen-iodine lasers (COILs) achieve oscillation on the ^2P1\\/2->^2P3\\/2 transition of atomic iodine at 1.315 mum by a series of excitation transfers from O2(^1delta). In electrically excited COILs, (eCOILs) the O2(^1delta) is produced in a flowing plasma, typically He\\/O2, at a few to tens of Torr. eCOILs additionally differ from conventional systems in the large amount of O atoms produced

Ramesh Arakoni; Natalie Y. Babaeva; Mark J. Kushner

2006-01-01

209

Enhancement of electric oxygen-iodine laser performance using a rectangular discharge and longer gain length  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a 95% enhancement in continuous-wave laser power on the 1315 nm transition of atomic iodine via a 50% increase in gain length, flow rates, and discharge power. O2(a ?1) is produced by a single radio-frequency-excited electric discharge sustained in an O2-He-NO gas mixture flowing through a rectangular geometry, and I(P21/2) is then pumped using energy transferred from O2(a ?1). A gain of 0.26% cm-1 was obtained and the total laser output power was 54.8 W.

Benavides, G. F.; Zimmerman, J. W.; Woodard, B. S.; Carroll, D. L.; Palla, A. D.; Day, M. T.; Verdeyen, J. T.; Solomon, W. C.

2009-11-01

210

COIL--Chemical Oxygen Iodine Laser: advances in development and applications  

NASA Astrophysics Data System (ADS)

Advantageous features of Chemical Oxygen-Iodine Laser (COIL) for laser technologies have increased considerably activities of international COIL communities during past ten years. They have been focused on the advanced concepts of hardware designs of the COIL subsystems, and testing and scaling-up of existing laser facilities. Prospective special applications of COIL technology, both civil and military, have received a significant attention and gained concrete aims. The paper is introduced by a brief description of the COIL operation mechanism and key device subsystems. It deals then with presentation of some investigated advanced concepts of singlet oxygen generators, alternative methods for atomic iodine generation, a mixing and ejector nozzle design to downsize a pressure recovery system, and optical resonators for high power COIL systems. The advanced diagnostics and computational modeling are also mentioned as very useful tools for critical insight into the laser kinetics and fluid dynamics, supporting thus the COIL research. The recent progress in the COIL development moves this laser closer to the application projects that are also briefly presented.

Kodymova, Jarmila

2005-09-01

211

Self-initiated volume discharge for production of atomic iodine in pulsed oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

This paper reports on investigating self-sustained volume discharge (SSVD) characteristics in CH3I, C3H7I, C4H9I, CF3I and their mixtures with SF6 and N2, employed as buffer gases, and with O2. The investigations performed in the plane-plane electrode system displaying high electric field edge enhancement have shown that in C3H7I, C4H9I and their mixtures with SF6, N2 and O2 SSVD is realized in the form of a self-initiated volume discharge (SIVD)- SSVD with no any preionization. Addition of SF6 or N2 in C3H7I, C4H9I leads to increasing the discharge stability, the latter being not adversely affected by addition of O2 in amounts of up to 300% of the iodide partial pressure. The fact that SSVD in C3H7I and C4H9I develops in the form of SIVD is indicative of these discharges to be promising for creation of high power pulsed and pulsed-periodic COIL. SIVD has been performed at total mixture pressures of up to 72 Torr and energy depositions of up to 130J/l in a volume of 1.5 l. The performed experimental modeling involving laser geometry of the discharge gap gives firm evidence that SIVD is promise for being used in creation of pulse and pulse-periodic COIL.

Belevtsev, Andrei A.; Firsov, Konstantin N.; Kazantsev, Sergey Y.; Saifulin, Alexei V.

2003-11-01

212

Test bed for a high throughput supersonic chemical oxygen - iodine laser  

SciTech Connect

The paper reports the development of a test bed for a chemical oxygen - iodine laser based on a high throughput jet flow singlet oxygen generator (JSOG). The system provides vertical singlet oxygen extraction followed by horizontal orientation of subsequent subsystems. This design enables the study of flow complexities and engineering aspects of a distributed weight system as an input for mobile and other platform-mounted systems developed for large scale power levels. The system under consideration is modular and consists of twin SOGs, plenum and supersonic nozzle modules, with the active medium produced in the laser cavity. The maximal chlorine flow rate for the laser is {approx}1.5 mole s{sup -1} achieving a typical chemical efficiency of about 18%. (lasers)

Singhal, Gaurav; Mainuddin; Rajesh, R; Varshney, A K; Dohare, R K; Kumar, Sanjeev; Singh, V K; Kumar, Ashwani; Verma, Avinash C; Arora, B S; Chaturvedi, M K; Tyagi, R K; Dawar, A L

2011-05-31

213

Semi-gas kinetics model for performance modeling of flowing chemical oxygen-iodine lasers (COIL)  

NASA Astrophysics Data System (ADS)

A semi-gas kinetics (SGK) model for performance analyses of flowing chemical oxygen-iodine laser (COIL) is presented. In this model, the oxygen-iodine reaction gas flow is treated as a continuous medium, and the effect of thermal motions of particles of different laser energy levels on the performances of the COIL is included and the velocity distribution function equations are solved by using the double-parameter perturbational method. For a premixed flow, effects of different chemical reaction systems, different gain saturation models and temperature, pressure, yield of excited oxygen, iodine concentration and frequency-shift on the performances of the COIL are computed, and the calculated output power agrees well with the experimental data. The results indicate that the power extraction of the SGK model considering 21 reactions is close to those when only the reversible pumping reaction is considered, while different gain saturation, models and adjustable parameters greatly affect the output power, the optimal threshold gain range, and the length of power extraction.

Gao, Zhi; Hu, Limin; Shen, Yiqing

2004-05-01

214

Observation of Pumping Reaction in an Amine-Based All Gas-Phase Iodine Laser Medium  

NASA Astrophysics Data System (ADS)

Gain measurement of all gas-phase iodine laser (AGIL) based on amine-based reactions is conducted. Three gaseous species, namely, NCl3, H, and HI are mixed in a glass tube, in which injection ports of each species are optimized using a numerical simulation code developed in our laboratory. The laser duct is attached downstream to the mixing tube, and a probe beam of 1315 nm passes at 23 cm downstream from the mixing point of H and HI. Hydrogen atoms are produced by the microwave discharge of the H2/He admixture. When NCl3 is not supplied, absorption by the 2P1/2-2P3/2 transition of iodine atoms is observed. When NCl3 is supplied, the absorption dip occasionally turns to the hump, which means that the energy transition from NCl(a1?) to iodine atoms results in population inversion. The observed small signal gain is 0.005%/cm. However, the reproducibility of the observed phenomenon is poor and presumably, some uncontrolled factor affects the gain evolution. To our knowledge, this is the first observation of a positive gain of the amine-based AGIL system.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2009-03-01

215

High-efficiency chemical oxygen-iodine laser using a streamwise vortex generator  

NASA Astrophysics Data System (ADS)

A supersonic expansion nozzle has allowed us to achieve highly efficient operation of the supersonic mixing chemical oxygen-iodine laser (COIL). The nozzle's shape produced a rapid mixing of the primary and secondary flows. Made up of a series of thin alternating wedges placed adjacent to each other, the nozzle looks like the letter X when it is viewed from the side. Iodine is injected at the exit plane of the nozzle and is strongly entrained by the streamwise vortices generated by the nozzle. 599 W of output power with a chemical efficiency of 32.9% is obtained, values higher by a factor of 1.4 than those of the conventional COIL.

Endo, Masamori; Osaka, Tatsuo; Takeda, Shuzaburo

2004-04-01

216

A study on an all gas-phase iodine laser based on NCl 3 reaction system  

NASA Astrophysics Data System (ADS)

Numerical simulation and flow-tube experiments are conducted to understand the chemistry of the amine based all gas-phase iodine laser (AGIL). The numerical simulation code developed is a one-dimensional, multiple-leaky-stream-tubes kinetics code combined with all the known rate equations to date. The validity of the code is confirmed to compare the calculated results with experimental results reported elsewhere. We find that the key reactions to achieve positive gain are the deactivation reaction of excited iodine atoms by chlorine atoms and the self annihilation reactions of NCl(1?). The order of the injection nozzles is crucial to suppress these reactions. It is shown that positive gain is possible with optimized flow rates and nozzle positions. Flow reactor experiments are conducted based on these calculations, and small signal gain is measured. The results are compared with the calculations.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2008-02-01

217

An efficient supersonic chemical oxygen-iodine laser operating without buffer gas and with simple nozzle geometry  

Microsoft Academic Search

We report on an efficient supersonic chemical oxygen-iodine laser, energized by a jet-type singlet oxygen generator, operating without primary buffer gas and applying simple nozzle geometry and transonic mixing of iodine and oxygen. Output power of 177 W with chemical efficiency of 17% was obtained in a 5 cm gain length for Cl2 flow rate of 11 mmol\\/s. The power

D. Furman; B. D. Barmashenko; S. Rosenwaks

1997-01-01

218

Role of N2 molecules in pulse discharge production of I atoms for a pulsed chemical oxygen-iodine laser  

Microsoft Academic Search

A pulsed electric discharge is the most effective means to turn chemical oxygen-iodine laser (COIL) operation into the pulse mode by fast production of iodine atoms. Experimental studies and numerical simulations are performed on a pulsed COIL initiated by an electric discharge in a mixture CF3I : N2 : O2(3X) : O2(a 1Deltag) flowing out of a chemical singlet oxygen

I. V. Kochetov; A. P. Napartovich; N. P. Vagin; N. N. Yuryshev

2011-01-01

219

O2(1?) and i(2p1\\/2) production in flowing afterglows for oxygen-iodine lasers: effect of no\\/no2 additives  

Microsoft Academic Search

Summary form only given. The chemical oxygen-iodine laser operates on the 1.315 mum I(1P12) rarr I(2P32) transition in atomic iodine; and is pumped by reactions between O2(1Delta) and molecular and atomic iodine. In electrically excited COIL lasers, (eCOIL), O2(1Delta) is produced in a plasma followed by injection of I2 in the afterglow containing the excited oxygen. The flowing afterglow additionally

R. A. Arakoni; N. Y. Babaeva; M. J. Kushner

2007-01-01

220

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments  

NASA Astrophysics Data System (ADS)

In an electric discharge oxygen-iodine laser, laser action at 1315nm on the I(P1/22)?I(P3/22) transition of atomic iodine is obtained by a near resonant energy transfer from O2(a?1) which is produced using a low-pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the postdischarge kinetics which are not encountered in a classic purely chemical O2(a?1) generation system. Mixing effects are also present. In this paper we present postdischarge modeling results obtained using a modified version of the BLAZE-II gas laser code. A 28 species, 105 reaction chemical kinetic reaction set for the postdischarge kinetics is presented. Calculations were performed to ascertain the impact of a two stream mixing mechanism on the numerical model and to study gain as a function of reactant mass flow rates. The calculations were compared with experimental data. Agreement with experimental data was improved with the addition of new kinetics and the mixing mechanism.

Palla, Andrew D.; Carroll, David L.; Verdeyen, Joseph T.; Solomon, Wayne C.

2006-07-01

221

Nearly attaining the theoretical efficiency of supersonic chemical oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

Improving the chemical efficiency of the supersonic chemical oxygen-iodine laser (COIL) is a key issue for the design of devices for both defense and industrial applications. Efficiencies around 30% for the supersonic COIL have been the state of the art in the last decade. Here, we report the achievement of a record (40%) for the chemical efficiency of the supersonic COIL. More specifically, we show that by carefully studying and optimizing the operation of the chemical generator, the mixing of heavy and light molecules in the gas phase and the optical extraction efficiency, we have approached the theoretical limit for the chemical efficiency.

Rybalkin, V.; Katz, A.; Barmashenko, B. D.; Rosenwaks, S.

2004-12-01

222

Mechanism of singlet oxygen deactivation in an electric discharge oxygen – iodine laser  

NASA Astrophysics Data System (ADS)

We have determined the influence of the reaction of molecular singlet oxygen with a vibrationally excited ozone molecule O2(a 1?) + O3(?) ? 2O2 + O on the removal rate of O2(a 1?) in an electric-discharge-driven oxygen – iodine laser. This reaction has been shown to be a major channel of O2(a 1?) loss at the output of an electric-discharge singlet oxygen generator. In addition, it can also contribute significantly to the loss of O2(a 1?) in the discharge region of the generator.

Azyazov, V. N.; Mikheyev, P. A.; Pershin, A. A.; Torbin, A. P.; Heaven, M. C.

2014-12-01

223

Plasma Excited Chemical-Oxygen-Iodine Lasers: Optimizing Injection and Mixing for Positive Gain  

NASA Astrophysics Data System (ADS)

Chemical oxygen-iodine lasers achieve oscillation on the ^2P1/2->^2P3/2 transition of atomic iodine at 1.315 ?m by a series of excitation transfers from O2(^1?). In electrically plasma excited devices (eCOILs), O2(^1?) is produced in a flowing plasma, typically He/O2, at a few to tens of Torr. The iodine is injected into the flow as a He/I2 mixture immediately upstream (or in) a supersonic nozzle. A small positive gain with I* limited to a narrow boundary layer near the wall indicates slow mixing when the I2 is injected from the wall. This results in low utilization of O2(^1?). In this paper we discuss results from 1- and 2-dimensional computational investigations of means to optimize gain in eCOILs by using different I2 injection strategies. It was found that due to the plasma generated distribution O2(^1?), placement of injectors closer to the axis significantly increased gain by facilitating complete O2(^1?)/I2 mixing. This is partly a function of the inlet flow of NO through the discharge which regulates the density of O atoms produced by electron impact dissociation of O2. By optimizing the nozzle dimensions, their location, and I2 and NO flow rates, the yield of O2(^1?) required to achieve positive gain can be minimized.

Babaeva, Natalia Y.; Garcia, Luis A.; Arakoni, Ramesh A.; Kushner, Mark J.

2007-10-01

224

Discharge Generation of Atomic Iodine  

Microsoft Academic Search

In this article we describe our new experimental device for generation of atomic iodine in discharge. This device will be a part of the COIL (chemical oxygen-iodine laser) and also DOIL (discharge oxygen-iodine laser) system. There are three main tasks which must be solved for a successful COIL operation: generation of atomic iodine, generation of singlet oxygen (excited oxygen molecule)

I. Pickova; V. Jirasek; J. Schmiedberger

2007-01-01

225

Chemical oxygen-iodine laser with a centrifugal spray generator of singlet oxygen  

NASA Astrophysics Data System (ADS)

A chemical oxygen-iodine laser driven by the centrifugal spray generator of singlet oxygen was developed and experimentally studied. Modeling and experimental studies showed that the designed generator can produce singlet oxygen, O2(1?g), with a high efficiency (chlorine utilization 0.68 - 0.87 and O2(1?g) yield 0.35 - 0.7) even at very high generator pressures (25 - 70 kPa), which cannot be attained by other O2(1?g) generators. This high-pressure operation should be beneficial for a pressure recovery system of the laser. Another specific feature of the generator is a very high BHP utilization (0.24-0.6). The developed separator can effectively remove even small droplets (> 1 ?m) from gas at the generator exit. Preliminary experiments on the COIL driven the centrifugal spray generator provided the small signal gain up to 0.5 % cm-1.

Špalek, Otomar; Jirásek, Vít; ?enský, Miroslav; Kodymová, Jarmila

2010-09-01

226

Singlet oxygen generator for a solar powered chemically pumped iodine laser  

NASA Technical Reports Server (NTRS)

The potential of solid phase endoperoxides as a means to produce single-delta oxygen in the gas phase in concentrations useful to chemical oxygen-iodine lasers was investigated. The 1,4 - endoperoxide of ethyl 3- (4-methyl - 1-naphthyl) propanoate was deposited over an indium-oxide layer on a glass plate. Single-delta oxygen was released from the endoperoxide upon heating the organic film by means of an electrical discharge through the conductive indium oxide coating. The evolution of singlet-delta oxygen was determined by measuring the dimol emission signal at 634 nm. Comparison of the measured signal with an analytic model leads to two main conclusions: virtually all the oxygen being evolved is in the singlet-delta state and in the gas phase, and there is no significant quenching other than energy pooling on the time scale of the experiment (approximately 10 msec). The use of solid phase endoperoxide as a singlet-delta oxygen generator for an oxygen-iodine laser appears promising.

Busch, G. E.

1984-01-01

227

Dissociation of I2 in chemical oxygen-iodine lasers: experiment, modeling, and pre-dissociation by electrical discharge  

Microsoft Academic Search

The dissociation of I2 molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three dimensional computational fluid dynamics calculations. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for

A. Katz; K. Waichman; Z. Dahan; V. Rybalkin; B. D. Barmashenko; S. Rosenwaks

2007-01-01

228

Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen-Iodine Laser System  

E-print Network

Oxygen Discharge and Post-Discharge Kinetics Experiments and Modeling for the Electric Oxygen a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels

Carroll, David L.

229

Output power enhancement of all gas-phase iodine laser by addition of hydrocarbon gases  

NASA Astrophysics Data System (ADS)

In this work, we studied the output power enhancement of an all gas-phase iodine laser (AGIL) by the addition of hydrocarbon gases. Enhancement is expected because hydrocarbon gases might scavenge Cl atoms, which are strong quenchers of the upper state of the laser medium, I(2 P 1/2). In AGILs, suppression of the Cl atom concentration is the key to improving the efficiency of the operation of the laser because Cl atoms are inherently generated by the self-annihilation of the energy donor, NCl(a1 ?). We found that the addition of CH4 gave the best results, because of its high scavenging rate constant and inertness to I(2 P 1/2). An enhancement of 10% was observed in the output power when CH4 was added at a flow rate twice that of NCl3. On the other hand, when C2H4 or C2H2 were added at the same flow rate as that of CH4, the output power reduced despite their fast removal rate of Cl atoms. The reason for the reduced output power was that the unsaturated bonds scavenged not only the Cl atoms but also the H atoms, resulting in a low density of H atoms, and this decelerated the production of NCl(a1 ?). The observed laser characteristics could reasonably be explained by numerical model calculations. To our knowledge, this is the first report of successful output power enhancement of an AGIL using a chemical agent.

Masuda, T.; Nakamura, T.; Endo, M.

2011-06-01

230

Design and performance of compact iodine stabilized He-Ne lasers at lambda =633 nm with a short optical resonator  

Microsoft Academic Search

The authors deal with portable He-Ne lasers at 633 nm, frequency stabilized by saturated absorption in 127I2. The construction of two different types of laser heads and electronic servo control units is described. The Invar head with Invar resonator and interchangeable elements (mirrors, discharge tube and iodine cell) yields 14 hyperfine structure (HFS) components (a-n) of the R(127)11-5 absorption line

F. Petru; B. Popela; Z. Vesela

1993-01-01

231

Gain Distribution and Output Power Measurements in a Scaled Electric Discharge Excited Oxygen-Iodine Laser1  

Microsoft Academic Search

Singlet delta oxygen (SDO) yield, gain in the supersonic cavity, and output power have been measured in a scaled-up electric discharge excited oxygen-iodine laser. The laser is using 5 kW transverse RF discharge operated at pressures of up to P0=90 torr to generate singlet delta oxygen in an oxygen-helium flow doped with NO. The total flow rate through the M=3

John R. Bruzzese; Adam C. Cole; Munetake Nishihara; Igor V. Adamovich

232

Gain and output power measurements in an electrically excited oxygen-iodine laser with a scaled discharge  

Microsoft Academic Search

Singlet delta oxygen (SDO) yield, small signal gain, and output power have been measured in a scaled electric discharge excited oxygen-iodine laser. Two different types of discharges have been used for SDO generation in O2-He-NO flows at pressures up to 90 Torr, crossed nanosecond pulser\\/dc sustainer discharge and capacitively coupled transverse RF discharge. The total flow rate through the laser

J. R. Bruzzese; A. Hicks; A. Erofeev; A. C. Cole; M. Nishihara; I. V. Adamovich

2010-01-01

233

Solar-pumped Er,Tm,Ho:YAG laser  

Microsoft Academic Search

Direct solar illumination was used to pump a 5-mm-diameter 62-mm exposed-length rod of Er,Tm,Ho:YAG to achieve a quasi-cw lasing of the Ho ion at an average power of 12 W. The solar radiation was chopped at a 20% duty cycle to avoid overloading of the cooling system. The peak power output was more than 65 W during the chopper's open

R. M. J. Benmair; J. Kagan; Y. Kalisky; Y. Noter; Moshe Oron; Y. Shimony; A. Yogev

1990-01-01

234

Achievement of positive gain in the amine-based all gas-phase iodine laser system  

NASA Astrophysics Data System (ADS)

Numerical simulation and flow-tube experiments are conducted to understand the chemistry of an amine-based all gasphase iodine laser (AGIL). The numerical simulation code developed is a one-dimensional, multiple-leaky-stream-tubes kinetics code combined with all the known rate equations to date. Using this code, we find that the key reactions to achieve positive gain are the deactivation reaction of excited iodine atoms by chlorine atoms and the self annihilation reactions of NCl(1?). The order of the injection nozzles is crucial to suppress these reactions. Flow reactor experiments are conducted based on these calculations, and small signal gain is measured. When NCl3 is not supplied, absorption of the I(2P1/2)-I(2P3/2) transition is observed. When NCl3 is supplied, the absorption is decreased and the dip occasionally turns to the hump, corresponding to a small signal gain of 5×10-3 %/cm. To our knowledge, this is the first observation of positive small signal gain of the amine-based AGIL system.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori; Uchiyama, Taro

2008-10-01

235

Catalytic enhancement of singlet oxygen for hybrid electric discharge oxygen-iodine laser systems  

NASA Astrophysics Data System (ADS)

We are investigating catalytically enhanced production of singlet oxygen, O2(a1?g), observed by reaction of O2/He discharge effluents on an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We have previously reported a two-fold increase in the O2(a) yields by this process, and corresponding enhancement of I(2P1/2) excitation and small-signal gain upon injection of I2. In this paper we report further observations of the effects of elevated temperature up to 410 K, and correlations of the catalytically generated O2(a) with atomic oxygen over a large range of discharge-flow conditions. We have applied a diffusion-limited reaction rate model to extrapolate the catalytic reaction rates to the highpressure, fast-flow conditions of the subsonic plenum of a supersonic EOIL test reactor. Using the model and the flow reactor results, we have designed and implemented a first-generation catalytic module for the PSI supersonic MIDJet/EOIL reactor. We describe preliminary tests with this module for catalyst coating deposition and enhancement of the small-signal gain observed in the supersonic flow. The observed catalytic effect could significantly benefit the development of high-power electrically driven oxygen-iodine laser systems.

Rawlins, Wilson T.; Lee, Seonkyung; Hicks, Adam J.; Konen, Ian M.; Plumb, Emily P.; Davis, Steven J.

2010-02-01

236

Mathematical modeling of a photovoltaic-laser energy converter for iodine laser radiation  

NASA Technical Reports Server (NTRS)

Space-based laser power systems will require converters to change laser radiation into electricity. Vertical junction photovoltaic converters are promising devices for this use. A promising laser for the laser power station is the t-C4F9I laser which emits radiation at a wavelength of 1.315 microns. This paper describes the results of mathematical modeling of a photovoltaic-laser energy converter for use with this laser. The material for this photovoltaic converter is Ga(53)In(47)As which has a bandgap energy of 0.94 eV, slightly below the energy of the laser photons (0.943 eV). Results of a study optimizing the converter parameters are presented. Calculated efficiency for a 1000 vertical junction converter is 42.5 percent at a power density of 1 x 10 to the 3d power w/sq cm.

Walker, Gilbert H.; Heinbockel, John H.

1987-01-01

237

O2-I laser (Oxygen-iodine) mixing studies using LIF (Laser Induced Fluorescence)  

Microsoft Academic Search

Laser Induced Fluorescence (LIF) was incorporated to study the degree of mixing in two subsonic nozzle variations for the O2-I laser system. The studies were performed using a testbed version of COIL-IV, an O2-I laser. I2 was injected through the nozzles and excited with an Ar laser to produce fluorescence. The observed jet trajectories could then be compared to trajectories

Y. D. Jones; D. Plummer; L. D. Watkins; G. D. Hager

1987-01-01

238

Real-time data acquisition and control system for a chemical oxygen iodine laser  

NASA Astrophysics Data System (ADS)

A user-friendly data acquisition and control system (DACS) for a chemical oxygen-iodine laser (COIL) has been developed. The system is capable of handling 117 analogue/digital channels for performing various operations such as on-line acquisition, control, display, safety measures and status indication of various subsystems. These operations are controlled either by control switches configured on a PC while not running or by a pre-determined sequence or timings during the run. The system is capable of real-time acquisition and on-line estimation of important diagnostic parameters for optimization of a COIL. The DACS system has been programmed using Advantech-GeniDAQ software. This software has also been used to convert the acquired data into graphical form. Using this DACS, more than 200 runs were given performed successfully.

Mainuddin; Tyagi, R. K.; Rajesh, R.; Singhal, Gaurav; Dawar, A. L.

2003-08-01

239

Singlet oxygen generators - the heart of chemical oxygen iodine lasers: past, present, and future  

NASA Astrophysics Data System (ADS)

Since the initial demonstration of chemical oxygen iodine lasers in 1977, researchers have realized that the heart of the COIL system is the singlet oxygen generator. This drives the performance of the system in terms of output power, mass efficiency, engineering complexity, reliability and maintainability. For this reason the singlet oxygen generator has been the focus of intense research and development efforts over the last 30 years. This paper reports on the history of singlet oxygen generators - starting with the simple sparger design used in the initial COIL demonstration and ending with current jet or droplet generators used in laboratories around the world. The relative performance of the different generator types will naturally lead to performance goals for the research efforts of the future.

Hewett, Kevin B.

2008-10-01

240

Phase retarder in chemical oxygen-iodine laser at 45-deg. incidence  

NASA Astrophysics Data System (ADS)

A phase retarder used in chemical oxygen-iodine laser (COIL) system has been fabricated by ion beam sputtering (IBS). When the incident angle is 45 deg. the reflectivity is about 99.9% from 1290 to 1340 nm and about 83.8% at 632.8 nm, and the phase retardance between the parallel and perpendicular polarization components is -92.8 deg. at 1315 nm. In order to get the influence of temperature on the phase retarder, six samples have been annealed from 523 to 648 K at interval of 25 K in air respectively, and the results show good temperature performance. With increasing temperature, phase retardance becomes smaller, and the variation is within 4 deg. at 1315 nm. At the same time, the variation maintains within +- 10 deg. for the incidence from 44 to 49 deg..

Wang, Fang; Huang, Jianbing; Wang, Yingjian; Fan, Zhengxiu

2006-02-01

241

New concepts of the chemistry of electric-discharge oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

The chemistry of electric discharge driven oxygen iodine lasers (EOIL) has long been believed to have O2(a1?g) as the sole energy carrier for excitation of the lasing state I(2P1/2), and O(3P) as the primary quencher of this state. In many sets of experimental measurements over a wide range of conditions, we have observed persistent evidence to the contrary. In this paper, we review our experimental data base in both room-temperature discharge-flow measurements and EOIL reactor results, in comparison to model predictions and kinetics analysis, to identify the missing production and loss terms in the EOIL reaction mechanism. The analysis points to a significantly higher level of understanding of this energetic chemical system, which can support advanced concepts in power scaling investigations.

Rawlins, Wilson T.; Lee, Seonkyung; Hicks, Adam J.; Konen, Ian M.; Oakes, David B.; Plumb, Emily P.; Davis, Steven J.

2011-03-01

242

Experimental investigation of a supersonic swept ramp injector using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

Planar measurements of injectant mole fraction and temperature have been conducted in a nonreacting supersonic combustor configured with underexpanded injection in the base of a swept ramp. The temperature measurements were conducted with a Mach 2 test section inlet in streamwise planes perpendicular to the test section wall on which the ramp was mounted. Injection concentration measurements, conducted in cross flow planes with both Mach 2 and Mach 2.9 free stream conditions, dramatically illustrate the domination of the mixing process by streamwise vorticity generated by the ramp. These measurements, conducted using a nonintrusive optical technique (laser-induced iodine fluorescence), provide an accurate and extensive experimental data base for the validation of computation fluid dynamic codes for the calculation of highly three-dimensional supersonic combustor flow fields.

Hartfield, Roy J.; Hollo, Steven D.; Mcdaniel, James C.

1990-01-01

243

Experimental investigation of a supersonic swept ramp injector using laser-induced iodine fluorescence  

NASA Astrophysics Data System (ADS)

Planar measurements of injectant mole fraction and temperature have been conducted in a nonreacting supersonic combustor configured with underexpanded injection in the base of a swept ramp. The temperature measurements were conducted with a Mach 2 test section inlet in streamwise planes perpendicular to the test section wall on which the ramp was mounted. Injection concentration measurements, conducted in cross flow planes with both Mach 2 and Mach 2.9 free stream conditions, dramatically illustrate the domination of the mixing process by streamwise vorticity generated by the ramp. These measurements, conducted using a nonintrusive optical technique (laser-induced iodine fluorescence), provide an accurate and extensive experimental data base for the validation of computation fluid dynamic codes for the calculation of highly three-dimensional supersonic combustor flow fields.

Hartfield, Roy J.; Hollo, Steven D.; McDaniel, James C.

1990-06-01

244

Characteristics of amine-based all-gas-phase iodine laser  

NASA Astrophysics Data System (ADS)

The characteristics of an amine-based all-gas-phase iodine laser (AGIL) are studied. At constant flow rates of the chemical species, the small-signal gain and laser output power are measured at three different positions in the flow reactor. It is clarified that the positive gain exceeding the threshold (2.3×10-3%/cm) is maintained over a region more than 80 mm long along the flow. The highest small-signal gain of 7.8×10-3%/cm and laser output power of 50 mW are observed at 170 mm downstream from the mixing point of HI and H. Numerical simulations suggest that the long positive-gain region is attributable to the following characteristics of the present apparatus: inefficient mixing and inefficient H2 dissociation. It is confirmed experimentally and numerically that these limitations are beneficial for extending the positive-gain region to the downstream; however, the optimum HI flow rate is limited a small value and results in a much lower gain than the theoretical limit. In order to achieve a higher gain, fast mixing and efficient H2 dissociation must be simultaneously achieved so as to increase the optimum HI flow rate. Numerical simulation results suggest that a positive gain of 5.4×10-2%/cm, a 7-times higher gain than that indicated by the present experimental results, should be obtained with the same NCl3 flow rate.

Masuda, T.; Nakamura, T.; Endo, M.

2010-12-01

245

Tomographic imaging of a target directly irradiated in experiments on the Iskra-5 iodine laser facility  

SciTech Connect

We set forth the data of experiments involving direct microtarget irradiation by the 12 second-harmonic beams ({lambda} = 0.66 {mu}m) of iodine laser radiation carried out on the Iskra-5 facility. For microtargets we employed glass shells {approx}500 {mu}m in diameter with {approx}1-{mu}m thick walls, which were filled with a DT mixture at a pressure p{sub DT} {approx} 3-4 atm. In one of these experiments, a tomographic image of the microtarget was recorded from the images obtained using pinhole cameras, which were arranged along seven different directions. The pinhole images were acquired in the X-ray radiation with photon energies above 1.5 keV. The procedure used for reconstructing the volume luminosity of the microtarget is described. An analysis of the tomographic image suggests that the compressed microtarget domain possesses a complex asymmetric shape; 20-30 {mu}m sized structural elements being clearly visible. The resultant data set allowed us to estimate the initial nonuniformity of microtarget surface irradiation by the laser radiation. The rms nonuniformity of microtarget irradiance was estimated at {approx}60 %. (interaction of laser radiation with targets)

Bondarenko, S V; Garanin, R V; Garanin, Sergey G; Zhidkov, N V; Oreshkov, O V; Potapov, S V; Suslov, N A; Frolova, N V [Russian Federal Nuclear Center 'All-Russian Research Institute of Experimental Physics', Sarov, Nizhnii Novgorod region (Russian Federation)

2010-12-29

246

Subwavenumber charge-coupled device spectrometer calibration using molecular iodine laser-induced fluorescence  

NASA Astrophysics Data System (ADS)

Spectrometers configured with charge-coupled devices (CCD) or other array-based detectors require calibration to convert from the pixel coordinate to a spectral coordinate. A CCD calibration method well suited for Raman spectroscopy has been developed based on the 514.5 nm Ar+ laser-induced fluorescence (LIF) spectrum of room-temperature molecular iodine vapor. Over 360 primary and secondary I2 LIF calibration lines spanning 510-645 nm were identified as calibrant peaks using an instrumental resolution of 1 cm-1. Two instrument calibration functions were evaluated with these peaks: a second-order polynomial and a function derived from simple optomechanical considerations. The latter function provided better fitting characteristics. Calibration using I2 LIF was tested with measurements of both laser light scattering and Raman spectra. The I2 LIF reference spectra and the signal spectra were recorded simultaneously, with no cross talk, by separating the two signals spatially along the vertical axis of the CCD imager. In this way, every CCD image could be independently calibrated. An accuracy and a precision of ±0.05 cm-1 were achieved with this calibration technique.

Lambert, Joseph G.; Hernandez-Diaz, Carlos; Williamson, J. Charles

2010-01-01

247

Investigation of Axially Flowing He/O2 Plasmas for Oxygen-Iodine Lasers  

NASA Astrophysics Data System (ADS)

Current trends in pumping chemical oxygen-iodine lasers (COIL) involve producing the O_2(^1? ) donor in axially flowing rf or pulsed electric discharges, thereby circumventing the hazards and complexity of conventional liquid-phase O_2(^1? ) production. Previous global-plug-flow modeling focused on developing reaction mechanisms and determining the specific energy deposition required to achieve high O_2(^1? ) yields. Recent experimental efforts have achieved positive laser gain with these energy depositions and have demonstrated the importance of upstream and downstream penetration of the plasma. In this work, we have examined the effects of axial transport (mass, momentum, and energy) on O_2(^1? ) yields in flowing He/O2 plasmas at a few to 10 Torr using a compressible 1D hydrodynamics and plasma kinetics model. Experimentally observed extension of short lived excited states upstream and downstream of the excitation zone is explained by electron thermal conduction and flow-induced extension of the plasma zone

Stafford, D. Shane; Kushner, Mark J.

2004-09-01

248

Time-resolved laser study of the transient absorption and conductivity on iodine-doped beta-carotene films  

Microsoft Academic Search

The transient microsecond absorption and photoconductivity in thin iodine(I)-doped (beta) - carotene (Car) films have been investigated. The laser nanosecond excitation ((lambda) equals 1064 and 512 nm) of the charge-transfer complex [Car+ (DOT) Ix-] (where x equals 3,5,7) leads to the appearance of a new transient absorption spectrum at 1250 nm. This absorption decays by the hyperbolic low as a

Stanislav L. Bondarev; Sergei M. Bachilo; I. I. Ivanov

1993-01-01

249

Pulsed Chemical Oxygen Iodine Lasers Excited by Pulse Gas Discharge with the Assistance of Surface Sliding Discharge Pre-ionization  

Microsoft Academic Search

Continuous-wave chemical oxygen-iodine lasers (COILs) can be operated in a pulsed operation mode to obtain a higher peak power. The key point is to obtain a uniform and stable glow discharge in the mixture of singlet delta oxygen and iodide. We propose using an electrode system with the assistance of surface sliding pre-ionization to solve the problem of the stable

Li Guo-Fu; Yu Hai-Jun; Duo Li-Ping; Jin Yu-Qi; Wang Jian; Sang Feng-Ting; Wang De-Zhen

2012-01-01

250

Investigations of processes in a glow electrical discharge singlet-oxygen generator for oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Singlet oxygen (SO) concentration exceeding 20% is obtained in pure oxygen with the help of a glow-discharge singlet oxygen generator (DSOG). SO concentration exceeding 30% is obtained using homogeneous or heterogeneous catalysts at 0.5-1 Torr of pure oxygen. The possibility to develop an electrical discharge singlet oxygen generator for oxygen-iodine lasers, which is an alternative to a SO chemical generator is demonstrated.

Lodin, V. J.; Ikonnikov, V. C.; Sirotin, S. A.; Zhdanovich, S. I.; Savin, Yuri V.; Adamenkov, Yu. A.; Rogojnikov, Yu. K.

2005-03-01

251

Kinetics and scaling of gain and lasing in a 1-5 kW microwave discharge oxygen iodine laser  

Microsoft Academic Search

Scaling of Electric Oxygen-Iodine Laser (EOIL) systems to higher powers requires extension of electric discharge powers into the kW range and beyond, with high efficiency and singlet oxygen yield. This paper describes the implementation of a moderate-power (1 to 5 kW) microwave discharge at 30 to 70 Torr pressure in a supersonic flow reactor designed for systematic investigations of the

Wilson T. Rawlins; Seonkyung Lee; Adam J. Hicks; Ian M. Konen; Emily P. Plumb; David B. Oakes; Steven J. Davis

2010-01-01

252

Investigations of processes in a glow electrical discharge singlet-oxygen generator for oxygen-iodine laser  

Microsoft Academic Search

Singlet oxygen (SO) concentration exceeding 20% is obtained in pure oxygen with the help of a glow-discharge singlet oxygen generator (DSOG). SO concentration exceeding 30% is obtained using homogeneous or heterogeneous catalysts at 0.5-1 Torr of pure oxygen. The possibility to develop an electrical discharge singlet oxygen generator for oxygen-iodine lasers, which is an alternative to a SO chemical generator

V. J. Lodin; V. C. Ikonnikov; S. A. Sirotin; S. I. Zhdanovich; Yuri V. Savin; Yu. A. Adamenkov; Yu. K. Rogojnikov

2005-01-01

253

Broadband femtosecond OPCPA system driven by the single-shot narrow-band iodine photodissociation laser SOFIA  

NASA Astrophysics Data System (ADS)

A two-stage optical parametric amplifier driven by a frequency-tripled beam from the high-energy iodine laser system SOFIA was built. This single-shot Optical Parametric Chirped Pulse-Amplification facility (OPCPA) and the system synchronizing the pump and signal pulses are described in detail. The chirped seed pulse of a Ti:sapphire oscillator running at the central wavelength of 800 nm is amplified in the two-stage (LBO and KDP) optical parametric amplifier over 108 times. The amplified spectral bandwidth of 68 nm corresponds to the pulse duration of 14 fs when a transform-limited pulse is assumed. This implies a compressed pulse of TW power. Systematic gain measurements reveal a good match with the theoretical predictions. Signal and idler beam fluence profiles are presented. The suitability of the iodine photo-dissociation laser as a pump source for the OPCPA technique is thus proved for the first time experimentally. A distinctive feature of the iodine laser is its very narrow gain bandwidth (<0.1 cm-1) and, therefore, the conventional chirped-pulse amplification technique does not lead to pulse durations at the femtosecond level.

Novák, O.; Tur?i?ová, H.; Smrž, M.; Huynh, J.; Pfeifer, M.; Straka, P.

2012-09-01

254

Properties of O2(1?)-I(2P1/2) laser medium with a dc glow discharge iodine atom generator  

NASA Astrophysics Data System (ADS)

Experiments were carried out in a flow cell apparatus under conditions corresponding to those of a typical oxygen-iodine laser. The cell was equipped with a chemical jet type singlet oxygen generator and an electric discharge for the production of iodine atoms. The properties of the discharge generator and the active medium were studied using laser-induced fluorescence and emission spectroscopy. I2 or CH3I entrained in a carrier flow of Ar were used as atomic iodine precursors. About 50% of the iodine contained in CH3I molecules was extracted in the generator. 2.6% of the electric power loaded into the discharge was used in CH3I dissociation. Right after the discharge 80%-90% of the iodine flow consisted of atoms. However, due to recombination during transport, only 20%-50% of atoms remained at the point of injection into the oxygen flow. A straightforward comparison of two methods of oxygen-iodine medium production—conventional, by means of I2 dissociation in the singlet oxygen flow and with iodine atoms produced externally in the electric discharge—was performed. It was found that the lifetime for the energy stored in singlet oxygen was about 30% longer, when atomic iodine was produced from CH3I in the discharge, as compared to the conventional chemical dissociation of I2 in the singlet oxygen flow.

Mikheyev, Pavel A.; Azyazov, Valeriy N.

2008-12-01

255

Numerical Simulation of Throat-mixing System for Supersonic Flow Chemical Oxygen-Iodine Laser  

NASA Astrophysics Data System (ADS)

Throat-mixing systems are proposed and assessed for the supersonic flow chemical oxygen-iodine laser (S-COIL). Three-dimensional, numerical simulation solving the governing equations of compressible gas flows together with chemical kinetics has been made for investigating the characteristics of the mixing condition and chemical reactions. The compressible Navier-Stokes equations and a chemical kinetic model encompassing 21 chemical reactions and 10 chemical species are solved by means of a full-implicit finite difference method. Two types of nozzles, a blade- and cylinder-type nozzles are adopted. The results show satisfactorily high values of the small signal gain coefficient G. The proposed throat-mixing system shows higher efficiency than the parallel mixing system. The blade-type nozzle is found to give 44% higher peak value of G than that of the parallel mixing system. It is also noted that the cylinder-type nozzle has superior ability than the parallel mixing system, in spite of its exceedingly simple structure.

Suzuki, Masataro; Suzuki, Takanori; Masuda, Wataru

256

Spray generator of singlet oxygen for a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A spray type of singlet oxygen generator for driving the Chemical Oxygen-Iodine Laser was developed. Singlet oxygen, O2(1?g), is generated by a fast reaction of chlorine with basic hydrogen peroxide solution in the form of a dense spray. A mathematical model of this reaction system showed that O2(1?g) can be generated in this system with a high yield (0.70-0.80), high utilization of chlorine (0.75-0.95), and effective utilization of liquid (0.36-0.54) at very high generator pressures (35-75 kPa). Experimental studies of this reaction system without an efficient separation of liquid proved an efficient O2(1?g) production characterized by a rather high product of chlorine utilization and O2(1?g) yield (0.4-0.9) at very high generator pressures (30-80 kPa). This pressure is much higher than the operation pressure used in other generators, which should be beneficial for a pressure recovery system of the COIL. These results provided the basis for designing a centrifugal spray generator with an efficient separation of liquid from the gas flow, which is the subject of the following paper.

Jirásek, V.; Hrubý, J.; Špalek, O.; ?enský, M.; Kodymová, J.

2010-09-01

257

Numerical analysis of spatial evolution of the small signal gain in a chemical oxygen iodine laser operating without primary buffer gas  

NASA Astrophysics Data System (ADS)

A chemical oxygen-iodine laser (COIL) that operates without primary buffer gas has become a new way of facilitating the compact integration of laser systems. To clarify the properties of spatial gain distribution, three-dimensional (3-D) computational fluid dynamics (CFD) technology was used to study the mixing and reactive flow in a COIL nozzle with an interleaving jet configuration in the supersonic section. The results show that the molecular iodine fraction in the secondary flow has a notable effect on the spatial distribution of the small signal gain. The rich iodine condition produces some negative gain regions along the jet trajectory, while the lean iodine condition slows down the development of the gain in the streamwise direction. It is also found that the new configuration of an interleaving jet helps form a reasonable gain field under appropriate operation conditions.

Hu, Zongmin; Jiang, Zonglin; Myong, Rhoshin; Cho, Taehwan

2008-02-01

258

Effect of nitric oxide on gain and output power of a non-self-sustained electric discharge pumped oxygen-iodine laser  

Microsoft Academic Search

This letter discusses the effect of nitric oxide on gain and output power of a pulser-sustainer discharge excited oxygen iodine laser. Adding small amounts of NO to the laser mixture (a few hundreds of ppm) considerably increases gain and output power due to (i) O atom titration and resultant slower I* atom quenching and (ii) improved stability of the dc

A. Hicks; J. Bruzzese; W. R. Lempert; J. W. Rich; I. V. Adamovich

2007-01-01

259

LASERS AND PHYSICAL PROCESSES IN THEM: A more accurate method of measuring the cross section for the 52P1\\/2-->52P3\\/2 transition of atomic iodine in photodissociation lasers based on dynamic self-diffraction  

Microsoft Academic Search

We have developed a new method for measuring the cross section for the 52P1\\/2-->52P3\\/2 transition of atomic iodine in photodissociation lasers. The inverse recombination of iodine atoms is monitored via dynamic self-diffraction of the laser radiation in the active medium. We have measured the cross section in mixtures of H-C3F7I and CF3I with Xe. This new method substantially increases the

K. S. Korol'kov; A. Yu Krylov; O. Yu Nosach; E. P. Orlov

1992-01-01

260

O2(1?) production and gain in plasma pumped oxygen iodine lasers: consequences of NO and NO2 additives  

NASA Astrophysics Data System (ADS)

The 1.315 µm [I(2P1/2) ? I(2P3/2)] transition of atomic iodine in the chemical oxygen-iodine laser (COIL) is pumped by sequential reactions of I2 and I with O2(1?). In electrically pumped systems (eCOILs), electron impact excitation of O2 produces the O2(1?) and also produces O atoms through dissociative excitation. The O atoms, through reactions with I2, I(2P1/2) and I(2P3/2), lead to dissociation of I2, quenching of the upper laser level and removal of the lower laser level. While dissociating I2 is potentially beneficial, quenching of the upper laser level is detrimental and so management of the O atom density is necessary to maximize laser gain. In this regard, NO and NO2 additives have been used to manage the O atom density by cyclically reacting with O and I. In this paper, results from a computational investigation of eCOIL systems using plug flow and two-dimensional models are discussed where NO and NO2 additives are used. The system is a flowing plasma sustained in He/O2/NO mixtures with downstream injection of NO2 followed by injection of I2. We found that addition of NO and NO2 is effective in managing the density of O atoms and maximizing gain by minimizing quenching of the upper laser level. We found that by optimizing the additives, laser gain can be maximized even though O2(1?) densities may be lower due to the management of quenching and dissociation reactions.

Arakoni, Ramesh A.; Babaeva, Natalia Y.; Kushner, Mark J.

2007-08-01

261

2D gasdynamic simulation of the kinetics of an oxygen-iodine laser with electric-discharge generation of singlet oxygen  

Microsoft Academic Search

The kinetic processes occurring in an electric-discharge oxygen-iodine laser are analyzed with the help of a 2D (r, z) gasdynamic model taking into account transport of excited oxygen, singlet oxygen, and radicals from the electric discharge\\u000a and their mixing with the iodine-containing gas. The main processes affecting the dynamics of the gas temperature and gain\\u000a are revealed. The simulation results

A. A. Chukalovsky; T. V. Rakhimova; K. S. Klopovsky; Yu. A. Mankelevich; O. V. Proshina

2011-01-01

262

Chemical Oxygen-Iodine Laser Diluted by CO2/N2 Buffer Gases with a Cryosorption Vacuum Pump  

NASA Astrophysics Data System (ADS)

Experiments were carried out on a verti-chemical oxygen-iodine laser (COIL), which was designed for N2 and energized by a square-pipe jet singlet oxygen generator (JSOG). A cryosorption vacuum pump was used as the pressure recovery system for CO2 and N2 buffer gases. The output power with CO2 was 27.3% lower than that with N2, but the zeolite bed showed an adsorption capacity threefold higher for CO2 than for N2 in the continuous operation with a Cl2 flow rate of 155 mmol/s and a total flow rate of 430±3 mmol/s.

Xu, Mingxiu; Sang, Fengting; Jin, Yuqi; Fang, Benjie; Chen, Fang; Geng, Zicai; Li, Yongzhao

2008-11-01

263

Oxygen discharge and post-discharge kinetics experiments and modeling for the electric oxygen-iodine laser system.  

PubMed

Laser oscillation at 1315 nm on the I(2P1/2)-->I(2P3/2) transition of atomic iodine has been obtained by a near resonant energy transfer from O2(a1Delta) produced using a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels of complexity to the singlet oxygen generator (SOG) kinetics which are not encountered in a classic purely chemical O2(a1Delta) generation system. The advanced model BLAZE-IV has been introduced to study the energy-transfer laser system dynamics and kinetics. Levels of singlet oxygen, oxygen atoms, and ozone are measured experimentally and compared with calculations. The new BLAZE-IV model is in reasonable agreement with O3, O atom, and gas temperature measurements but is under-predicting the increase in O2(a1Delta) concentration resulting from the presence of NO in the discharge and under-predicting the O2(b1Sigma) concentrations. A key conclusion is that the removal of oxygen atoms by NOX species leads to a significant increase in O2(a1Delta) concentrations downstream of the discharge in part via a recycling process; however, there are still some important processes related to the NOX discharge kinetics that are missing from the present modeling. Further, the removal of oxygen atoms dramatically inhibits the production of ozone in the downstream kinetics. PMID:17461557

Palla, A D; Zimmerman, J W; Woodard, B S; Carroll, D L; Verdeyen, J T; Lim, T C; Solomon, W C

2007-07-26

264

Design investigation of solar powered lasers for space applications  

Microsoft Academic Search

The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the

R. Taussig; C. Bruzzone; D. Quimby; L. Nelson; W. Christiansen; S. Neice; P. Cassady; A. Pindroh

1979-01-01

265

Output power enhancement of an amine-based all gas-phase iodine laser by addition of methane gas  

NASA Astrophysics Data System (ADS)

Output power enhancement of an all gas-phase iodine laser (AGIL) by addition of hydrocarbon gases is studied. It is expected because hydrocarbon gases might scavenge Cl atoms, which are strong quencher of the upper state of the laser medium, I(2P1/2). In AGILs, suppression of the Cl atom concentration is the key to improving the efficiency of laser operation because Cl atoms are inherently generated by the self-annihilation of the energy donor, NCl(a1?). We found that the addition of CH4 gave the best results because of its high scavenging rate constant and inertness to I(2P1/2). An enhancement of 10% was observed in the output power when CH4 was added at a flow rate twice that of NCl3. On the other hand, when C2H4 or C2H2 were added at the same flow rate as that of CH4, the output power reduced despite their fast removal rate of Cl atoms. The reason for the reduced output power was that the unsaturated bonds scavenged not only the Cl atoms but also the H atoms, resulting in a low density of H atoms, and this decelerated the production of NCl(a1?). The observed laser characteristics could be reasonably explained by numerical model calculations.

Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

2010-09-01

266

Numerical analysis of spatial evolution of the small signal gain in a chemical oxygen–iodine laser operating without primary buffer gas  

Microsoft Academic Search

A chemical oxygen–iodine laser (COIL) that operates without primary buffer gas has become a new way of facilitating the compact integration of laser systems. To clarify the properties of spatial gain distribution, three-dimensional (3-D) computational fluid dynamics (CFD) technology was used to study the mixing and reactive flow in a COIL nozzle with an interleaving jet configuration in the supersonic

Zongmin Hu; Zonglin Jiang; Rhoshin Myong; Taehwan Cho

2008-01-01

267

Reduced dimer production in solar-simulator-pumped continuous wave iodine lasers based on model simulations and scaling and pumping studies  

NASA Technical Reports Server (NTRS)

A numerical rate equation model for a continuous wave iodine laser with longitudinally flowing gaseous lasant is validated by approximating two experiments that compare the perfluoroalkyl iodine lasants n-C3F7I and t-C4F9I. The salient feature of the simulations is that the production rate of the dimer (C4F9)2 is reduced by one order of magnitude relative to the dimer (C3F7)2. The model is then used to investigate the kinetic effects of this reduced dimer production, especially how it improves output power. Related parametric and scaling studies are also presented. When dimer production is reduced, more monomer radicals (t-C4F9) are available to combine with iodine ions, thus enhancing depletion of the laser lower level and reducing buildup of the principal quencher, molecular iodine. Fewer iodine molecules result in fewer downward transitions from quenching and more transitions from stimulated emission of lasing photons. Enhanced depletion of the lower level reduces the absorption of lasing photons. The combined result is more lasing photons and proportionally increased output power.

Costen, Robert C.; Heinbockel, John H.; Miner, Gilda A.; Meador, Willard E., Jr.; Tabibi, Bagher M.; Lee, Ja H.; Williams, Michael D.

1995-01-01

268

Role of N2 molecules in pulse discharge production of I atoms for a pulsed chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A pulsed electric discharge is the most effective means to turn chemical oxygen-iodine laser (COIL) operation into the pulse mode by fast production of iodine atoms. Experimental studies and numerical simulations are performed on a pulsed COIL initiated by an electric discharge in a mixture CF3I : N2 : O2(3X) : O2(a 1?g) flowing out of a chemical singlet oxygen generator. A transverse pulsed discharge is realized at various iodide pressures. The model comprises a system of kinetic equations for neutral and charged species, the electric circuit equation, the gas thermal balance equation and the photon balance equation. Reaction rate coefficients for processes involving electrons are repeatedly re-calculated by the electron Boltzmann equation solver when the plasma parameters are changed. The processes accounted for in the Boltzmann equation include direct and stepwise excitation and ionization of atoms and molecules, dissociation of molecules, electron attachment processes, electron-ion recombination, electron-electron collisions and second-kind collisions. The last processes are particularly important because of a high singlet oxygen concentration in gas flow from the singlet oxygen chemical generator. A conclusion is drawn about satisfactory agreement between the theory and the experiment.

Kochetov, I. V.; Napartovich, A. P.; Vagin, N. P.; Yuryshev, N. N.

2011-09-01

269

Catalytic enhancement of singlet oxygen production and optical gain in electric discharge oxygen-iodine laser systems  

NASA Astrophysics Data System (ADS)

We are investigating catalytically enhanced production of singlet oxygen, O2(a1?g), observed by reaction of O2/He discharge effluents over an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We have previously reported a two-fold increase in the O2(a) yields by this process, and corresponding enhancement of I(2P1/2) excitation and small-signal gain upon injection of I2 and NO2. In this paper we review observed I* excitation behavior and correlations of the catalytically generated O2(a) with atomic oxygen over a large range of discharge-flow conditions to develop a conceptual reaction mechanism for the phenomena. We describe a first-generation catalytic module for the PSI supersonic MIDJet/EOIL reactor, and tests with this module for catalyst coating deposition and enhancement of the small-signal gain observed in the supersonic flow. The results present compelling evidence for catalytic production of vibrationally excited O2(X,v) and its participation in the I* excitation process. The observed catalytic effects could significantly benefit the development of high-power electrically driven oxygen-iodine laser systems.

Lee, Seonkyung; Rawlins, Wilson T.; Hicks, Adam J.; Konen, Ian M.; Plumb, Emily P.; Davis, Steven J.

2011-03-01

270

Catalytic enhancement of singlet oxygen for hybrid electric discharge oxygen-iodine laser systems  

Microsoft Academic Search

We are investigating catalytically enhanced production of singlet oxygen, O2(a1▵g), observed by reaction of O2\\/He discharge effluents on an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We have previously reported a two-fold increase in the O2(a) yields by this process, and corresponding enhancement of I(2P1\\/2) excitation and small-signal gain upon injection of I2. In this

Wilson T. Rawlins; Seonkyung Lee; Adam J. Hicks; Ian M. Konen; Emily P. Plumb; Steven J. Davis

2010-01-01

271

Gain measurements in a non-self-sustained electric discharge pumped oxygen-iodine laser cavity  

Microsoft Academic Search

The paper presents results of singlet delta oxygen yield (SDO) measurements in a high-pressure, non-self-sustained discharge and small signal gain measurements on the 1315 nm iodine atom transition in the M=3 supersonic cavity downstream of the discharge. The results demonstrate operation of a stable pulser-sustainer discharge in O2-He flows at pressures of up to 120 torr and discharge powers of

A. Hicks; K. Fredrickson; S. Tirupathi; Y. G. Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich; K. L. Galbally-Kinney; W. J. Kessler; W. T. Rawlins; P. A. Mulhall; S. J. Davis

2007-01-01

272

Gain Measurements in a Non-Self-Sustained Electric Discharge Pumped Oxygen-Iodine Laser Cavity  

Microsoft Academic Search

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 O2 -- He mixtures at pressures of up to P0=120 torr and

Igor Adamovich; Adam Hicks; Yurii Utkin; Walter Lempert; J. William Rich

2006-01-01

273

Improving the effectiveness of solar pumping systems by using modular centrifugal pumps with variable rotational speed  

Microsoft Academic Search

The possibility of improving the performance of deep well solar pumping systems by using centrifugal pumps with variable rotational speed and modular number of working stages (i.e. Divided Shaft Pump, DSP) was investigated and compared with traditional systems equipped with pumps having a fixed number of stages (i.e Standard Centrifugal Pump, SCP). Starting from commercially available pumps with a given

Daniele Fiaschi; Roberto Graniglia; Giampaolo Manfrida

2005-01-01

274

How many O2(1?) molecules are consumed per dissociated I2 in chemical oxygen-iodine lasers?  

NASA Astrophysics Data System (ADS)

Direct measurements of the dissociation of I2 molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) as a function of I2 flow rate were carried out. This enabled us to determine the number of consumed O2(?1) molecules per dissociated I2 molecule. The number depends on the experimental conditions: it is 4.2±0.4 for typical conditions and I2 densities applied for the operation of the COIL, but increases at lower I2 densities. Possible dissociation mechanisms consistent with our results are discussed and the importance of dissociating I2 prior to its mixing with O2(?1) is stressed.

Rybalkin, V.; Katz, A.; Waichman, K.; Vingurt, D.; Dahan, Z.; Barmashenko, B. D.; Rosenwaks, S.

2006-07-01

275

Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2(a1?) produced in an electric discharge  

NASA Astrophysics Data System (ADS)

Laser action at 1315nm on the I(P1/22)?I(P3/22) transition of atomic iodine is conventionally obtained by a near-resonant energy transfer from O2(a1?) which is produced using wet-solution chemistry. The difficulties in chemically producing O2(a1?) has motivated investigations into purely gas phase methods to produce O2(a1?) using low-pressure electric discharges. In this letter, we report on the demonstration of a continuous-wave laser on the 1315nm transition of atomic iodine where the O2(a1?) used to pump the iodine was produced by a radio-frequency-excited electric discharge. The electric discharge was sustained in a He /O2 gas mixture upstream of a supersonic cavity which is employed to lower the temperature of the continuous gas flow and shift the equilibrium of atomic iodine in favor of the I(P1/22) state. The laser output power was 220mW in a stable cavity composed of two 99.99% reflective mirrors.

Carroll, David L.; Verdeyen, Joseph T.; King, Darren M.; Zimmerman, Joseph W.; Laystrom, Julia K.; Woodard, Brian S.; Benavides, Gabriel F.; Kittell, Kirk; Stafford, D. Shane; Kushner, Mark J.; Solomon, Wayne C.

2005-03-01

276

Investigation of possibilities for solar-powered high-energy lasers in space  

NASA Technical Reports Server (NTRS)

Solar pumped lasers were investigated. The literature was reviewed for possible solar laser candidates from optical pumping experiments. A baseline CO electric discharge laser system was shown to be technically feasible. The most promising direct solar pumped laser was identified to be CF3I. Using the 'STAG' solar laser concept and CF3I, it was found that such a system could be weight competitive with the baseline CO laser system.

1982-01-01

277

Three-block model of the kinetics of vibrationally excited I{sub 2}(X) molecules in the active media of oxygen - iodine lasers  

SciTech Connect

A three-block model of the kinetics of vibrationally excited I{sub 2}(X) molecules in the active media of chemical oxygen - iodine lasers is developed. Instead of the system of equations describing a change in the concentrations of I{sub 2}(X, u) (u=0 - 47) molecules, this model uses equations for the total concentrations of iodine molecules belonging to the blocks of vibrational levels with u {<=} 10, u = 11 - 24, and u {>=} 25. Effective deactivation rate constants of I{sub 2}(X, 11 {<=} u {<=} 24) molecules are found for laser media of different compositions. The results of calculations performed using the proposed model agree with experimental data and are close to the parameters calculated previously by using the total system of equations for populations of individual vibrational levels of I{sub 2}(X, u). (laser applications and other topics in quantum electronics)

Pichugin, S Yu [Samara Branch of the P.N. Lebedev Physical Institute, Russian Academy of Sciences, Samara (Russian Federation)

2012-09-30

278

Zeeman effects in the hyperfine structure of atomic iodine photodissociation laser emission.  

NASA Technical Reports Server (NTRS)

Observation of hyperfine structure in laser emission from CF3I and C2F5I photodissociation lasers. Constant magnetic fields affect the time behavior of the emission by changing the relative gains of the hyperfine transitions. Time-varying fields usually present in photodissociation lasers further complicate the emission.

Hwang, W. C.; Kasper, J. V. V.

1972-01-01

279

Pulsed Chemical Oxygen Iodine Lasers Excited by Pulse Gas Discharge with the Assistance of Surface Sliding Discharge Pre-ionization  

NASA Astrophysics Data System (ADS)

Continuous-wave chemical oxygen-iodine lasers (COILs) can be operated in a pulsed operation mode to obtain a higher peak power. The key point is to obtain a uniform and stable glow discharge in the mixture of singlet delta oxygen and iodide. We propose using an electrode system with the assistance of surface sliding pre-ionization to solve the problem of the stable glow discharge with a large aperture. The pre-ionization unit is symmetrically fixed on the plane of the cathode surface. A uniform and stable glow discharge is obtained in a mixture of iodide (such as CH3I) and nitrogen at the specific deposition energy of 4.5 J/L, pressure of 1.99-3.32 kPa, aperture size of 11 cm × 10 cm. The electrode system is applied in a pulsed COIL. Laser energy up to 4.4 J is obtained and the specific energy output is 2 J/L.

Li, Guo-Fu; Yu, Hai-Jun; Duo, Li-Ping; Jin, Yu-Qi; Wang, Jian; Sang, Feng-Ting; Wang, De-Zhen

2012-05-01

280

Design investigation of solar powered lasers for space applications. Final report  

Microsoft Academic Search

The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the

R. Taussig; C. Bruzzone; D. Quimby; L. Nelson; W. Christiansen

1979-01-01

281

Continuous-wave laser oscillation in subsonic flow on the 1315 nm atomic iodine transition pumped by electric discharge produced O2(a 1?)  

NASA Astrophysics Data System (ADS)

Herein the authors report on the demonstration of a continuous-wave laser in subsonic flow on the 1315nm transition of atomic iodine using the energy transferred to I(P1/22) from O2(a?1) produced by a radio-frequency-excited electric discharge. The electric discharge was sustained in an O2-He -NO gas mixture. Downstream of the discharge, cold gas injection was employed to raise the gas density and lower the temperature of the continuous gas flow to shift the equilibrium of atomic iodine in favor of the I(P1/22) state. The laser output power was 540mW in a stable cavity with two 99.993% reflective mirrors.

Verdeyen, Joseph T.; Carroll, David L.; King, Darren M.; Laystrom, Julia K.; Benavides, Gabriel F.; Zimmerman, Joseph W.; Woodard, Brian S.; Solomon, Wayne C.

2006-09-01

282

The electric oxygen-iodine laser: Chemical kinetics of O2(a 1 ?) production and I(2P1\\/2) excitation in microwave discharge systems  

Microsoft Academic Search

Generation of singlet oxygen metastables, O2(a 1 ?), in an electric discharge plasma offers the potential for development of compact electric oxygen-iodine laser (EOIL) systems using a recyclable, all-gas-phase medium. The primary technical challenge for this concept is to develop a high-power, scalable electric discharge configuration that can produce high yields and flow rates of O2(a) to support I( 2

W. T. Rawlins; S. Lee; W. J. Kessler; D. B. Oakes; L. G. Piper; S. J. Davis

283

The electric oxygen-iodine laser: chemical kinetics of O2(a1Delta) production and I(2 P1\\/2) excitation in microwave discharge systems  

Microsoft Academic Search

Generation of singlet oxygen metastables, O2(a1Delta), in an electric discharge plasma offers the potential for development of compact electric oxygen-iodine laser (EOIL) systems using a recyclable, all-gas-phase medium. The primary technical challenge for this concept is to develop a high-power, scalable electric discharge configuration that can produce high yields and flow rates of O2(a) to support I(2P1\\/2->2P3\\/2) lasing at high

W. T. Rawlins; S. Lee; W. J. Kessler; D. B. Oakes; L. G. Piper; S. J. Davis

2006-01-01

284

Advanced chemical lasers  

NASA Astrophysics Data System (ADS)

A review of recent advances in chemical laser technology is presented. New technology and concepts related to the Chemical Oxygen Iodine Laser (COIL), All Gas-phase Iodine Laser (AGIL), and HF Overtone Laser are discussed.

Manke, Gerald C., II; Hewett, Kevin B.; Madden, Timothy J.; McCord, John E.; Wisniewski, Charles F.; Hager, Gordon D.

2004-09-01

285

Picosecond dynamics of reactions in the liquid phase: studies of iodine photodissociation and development of new laser techniques  

SciTech Connect

Iodine photodissociation and recombination was studied as a model for processes common to chemical reaction in the liquid phase. Picosecond transient absorption measurements from 1000 to 295 nm were used to monitor the dynamics in a variety of solvents. Most of the atoms which undergo geminate recombination were found to do so in less than or equal to 15 ps, in agreement with the results of existing molecular dynamics simulations. Vibrational relaxation times vary from approx.15 ps near the middle of the ground state well to approx.150 ps for complete relaxation to v = 0. The prediction of strong resonant vibrational energy transfer to chlorinated methane solvents was not supported, but some evidence for this mechanism was found for alkane solvents. Current theory is unable to explain the large variation (65 to 2700 ps) of the excited A'-state lifetime in various solvents. The 10-Hz amplified, synchronously-pumped dye laser which was used in these studies is described and characterized. SERS (Stimulated Electronic Raman Scattering) and difference frequency mixing were used in the generation of the infrared and far-infrared, respectively. 54 refs., 38 figs., 3 tabs. (WRF)

Berg, M.A.

1985-09-01

286

Toward understanding the dissociation of I2 in chemical oxygen-iodine lasers: Combined experimental and theoretical studies  

NASA Astrophysics Data System (ADS)

The dissociation of I2 molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three-dimensional computational fluid dynamics calculations. The measurements, briefly reported in a recent paper [Rybalkin et al., Appl. Phys. Lett. 89, 021115 (2006)] and reanalyzed in detail here, revealed that the number N of consumed O2(a?g1) molecules per dissociated I2 molecule depends on the experimental conditions: it is 4.5±0.4 for typical conditions and I2 densities applied for optimal operation of the COIL but increases at lower I2 densities. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for the gain, temperature, I2 dissociation fraction, and N at the optical axis. The suggested mechanism combines the recent scheme of Azyazov and Heaven [AIAA J. 44, 1593 (2006)], where I2(A'?2u3), I2(A?1u3), and O2(a?g1,v) are significant dissociation intermediates, with the "standard" chain branching mechanism of Heidner III et al. [J. Phys. Chem. 87, 2348 (1983)], involving I(P1/22) and I2(X?g +1,v).

Waichman, K.; Rybalkin, V.; Katz, A.; Dahan, Z.; Barmashenko, B. D.; Rosenwaks, S.

2007-07-01

287

Dissociation of I II in chemical oxygen-iodine lasers: experiment, modeling, and pre-dissociation by electrical discharge  

NASA Astrophysics Data System (ADS)

The dissociation of I II molecules at the optical axis of a supersonic chemical oxygen-iodine laser (COIL) was studied via detailed measurements and three dimensional computational fluid dynamics calculations. Comparing the measurements and the calculations enabled critical examination of previously proposed dissociation mechanisms and suggestion of a mechanism consistent with the experimental and theoretical results obtained in a supersonic COIL for the gain, temperature and I II dissociation fraction at the optical axis. The suggested mechanism combines the recent scheme of Azyazov and Heaven (AIAA J. 44, 1593 (2006)), where I II(A' 3? 2u), I II(A 3? 1u) and O II(a1? g, v) are significant dissociation intermediates, with the "standard" chain branching mechanism of Heidner et al. (J. Phys. Chem. 87, 2348 (1983)), involving I(2P 1/2) and I II(X1? + g, v). In addition, we examined a new method for enhancement of the gain and power in a COIL by applying DC corona/glow discharge in the transonic section of the secondary flow in the supersonic nozzle, dissociating I II prior to its mixing with O II(1?). The loss of O II(1?) consumed for dissociation was thus reduced and the consequent dissociation rate downstream of the discharge increased, resulting in up to 80% power enhancement. The implication of this method for COILs operating beyond the specific conditions reported here is assessed.

Katz, A.; Waichman, K.; Dahan, Z.; Rybalkin, V.; Barmashenko, B. D.; Rosenwaks, S.

2007-06-01

288

Chemistry of I(2P1/2) excitation in a hybrid catalytic electric-discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The chemistry of electric discharge driven oxygen iodine lasers (EOIL) has long been believed to have O2(a1?g) as the sole energy carrier for excitation of the lasing state I(2P1/2), and O(3P) as the primary quencher of this state. In many sets of experimental measurements over a wide range of conditions, we have observed persistent evidence to the contrary. In this paper, we examine comparisons of kinetics analysis and model predictions to experimental results from a supersonic EOIL research reactor. This analysis leads to identification of important additional production and loss terms for the lasing species, I(2P1/2), in the EOIL reaction mechanism. These mechanisms are also relevant to the catalytically enhanced EOIL excitation mechanism. Exploitation of this chemistry can lead to substantial increases in gain and power extraction efficiency in larger-scale EOIL systems. The analysis points to a significantly higher level of understanding of this energetic chemical system, which can support application of advanced concepts in power scaling investigations.

Rawlins, Wilson T.; Lee, Seonkyung; Davis, Steven J.

2012-03-01

289

INTERACTION OF LASER RADIATION WITH TARGETS Tomographic imaging of a target directly irradiated in experiments on the Iskra-5 iodine laser facility  

NASA Astrophysics Data System (ADS)

We set forth the data of experiments involving direct microtarget irradiation by the 12 second-harmonic beams (? = 0.66 ?m) of iodine laser radiation carried out on the Iskra-5 facility. For microtargets we employed glass shells ~500 ?m in diameter with ~1-?m thick walls, which were filled with a DT mixture at a pressure pDT approx 3-4 atm. In one of these experiments, a tomographic image of the microtarget was recorded from the images obtained using pinhole cameras, which were arranged along seven different directions. The pinhole images were acquired in the X-ray radiation with photon energies above 1.5 keV. The procedure used for reconstructing the volume luminosity of the microtarget is described. An analysis of the tomographic image suggests that the compressed microtarget domain possesses a complex asymmetric shape; 20-30 ?m sized structural elements being clearly visible. The resultant data set allowed us to estimate the initial nonuniformity of microtarget surface irradiation by the laser radiation. The rms nonuniformity of microtarget irradiance was estimated at ~60 %.

Bondarenko, S. V.; Garanin, R. V.; Garanin, Sergey G.; Zhidkov, N. V.; Oreshkov, O. V.; Potapov, S. V.; Suslov, N. A.; Frolova, N. V.

2010-12-01

290

Electron-beam sustained discharge in oxygen gas mixtures: singlet delta oxygen production for oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Electric properties and spectroscopy of an e-beam sustained discharge (EBSD) in oxygen and oxygen gas mixtures at gas pressure up to 100 Torr were experimentally studied. The pulsed discharge in pure oxygen and its mixtures with noble gases was shown to be very unstable and characterized by low input energy. When adding small amount of carbon monoxide or hydrogen, the electric stability of the discharge increases, specific input energy (SIE) per molecular component being more than order of magnitude higher and coming up to 6.5 kJ/(l atm) for gas mixture O2:Ar:CO = 1:1:0.1. The results of experiments on spectroscopy of the singlet delta oxygen O2(a1?g)(SDO) and O2(b1?g+) states in the EBSD are presented. The calibration of the optical scheme for measuring the SDO absolute concentration and yield using the detection of luminescence of the SDO going from a chemical SDO generator was done. The preliminary measurement of the SDO yield demonstrated that it was ~3% for the SIE of ~1 kJ/(l atm), which is close to the results of theoretical calculations for such a SIE. Theoretical calculations demonstrated that for the SIE of 6.5 kJ/(l atm) the SDO yield may reach ~20% exceeding its threshold value needed for oxygen-iodine laser operation at room temperature, although a part of the energy loaded into the EBSD goes into the vibrational energy of the molecular admixture, (which was experimentally demonstrated by launching a CO laser operating on an oxygen-rich mixture O2:Ar:CO = 1:1:0.1 and measuring its small-signal gain).

Frolov, Mikhail P.; Hager, Gordon D.; Ionin, Andrei A.; Klimachev, Yurii M.; Kochetov, Igor V.; Kotkov, Andrei A.; McIver, John K.; Napartovich, Anatolii P.; Podmar'kov, Yurii P.; Seleznev, Leonid V.; Sinitsyn, Dmitrii V.; Vagin, Nikolai P.; Yuryshev, Nikolay N.

2004-09-01

291

Mixing effects in postdischarge modeling of electric discharge oxygen-iodine laser experiments  

Microsoft Academic Search

which are not encountered in a classic purely chemical O2a 1 generation system. Mixing effects are also present. In this paper we present postdischarge modeling results obtained using a modified version of the BLAZE-II gas laser code. A 28 species, 105 reaction chemical kinetic reaction set for the postdischarge kinetics is presented. Calculations were performed to ascertain the impact of

Andrew D. Palla; David L. Carroll; Joseph T. Verdeyen; Wayne C. Solomon

2006-01-01

292

Kinetics and scaling of gain and lasing in a 1-5 kW microwave discharge oxygen iodine laser  

NASA Astrophysics Data System (ADS)

Scaling of Electric Oxygen-Iodine Laser (EOIL) systems to higher powers requires extension of electric discharge powers into the kW range and beyond, with high efficiency and singlet oxygen yield. This paper describes the implementation of a moderate-power (1 to 5 kW) microwave discharge at 30 to 70 Torr pressure in a supersonic flow reactor designed for systematic investigations of the scaling of gain and lasing with power and flow conditions. The 2450 MHz microwave discharge is confined near the flow axis by a swirl flow. The discharge effluent, containing active species including O2(a1?), O(3P), and O3, passes through a 2-D flow duct equipped with a supersonic nozzle and cavity. I2 is injected upstream of the supersonic nozzle. The apparatus is water-cooled, and is modular to permit a variety of inlet, nozzle, and optical configurations. A comprehensive suite of optical emission and absorption diagnostics monitors the absolute concentrations of O2(a), O(3P), O3, I2, I(2P3/2), I(2P1/2), small-signal gain, and temperature in both the subsonic and supersonic flow streams. The experimental results include numerous observations of positive gain and lasing in supersonic flow, and the scaling of gain with a variety of flow and reaction rate conditions. The results are compared with kinetics modeling predictions to highlight key discrepancies as well as areas of agreement. The observed gains are generally lower than the predicted values, due in part to chemical kinetics effects and also due to mixing limitations specific to the reagent injection design. We discuss in detail the observed effects related to O-atom chemistry, and their import for scaling the gain to higher levels. We also will present initial beam quality measurements.

Rawlins, Wilson T.; Lee, Seonkyung; Hicks, Adam J.; Konen, Ian M.; Plumb, Emily P.; Oakes, David B.; Davis, Steven J.

2010-02-01

293

Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2(a1?) produced in an electric discharge  

Microsoft Academic Search

Laser action at 1315 nm on the I(2P1?2)?I(2P3?2) transition of atomic iodine is conventionally obtained by a near-resonant energy transfer from O2(a1?) which is produced using wet-solution chemistry. The difficulties in chemically producing O2(a1?) has motivated investigations into purely gas phase methods to produce O2(a1?) using low-pressure electric discharges. In this letter, we report on the demonstration of a continuous-wave

David L. Carroll; Joseph T. Verdeyen; Darren M. King; Joseph W. Zimmerman; Julia K. Laystrom; Brian S. Woodard; Gabriel F. Benavides; Kirk Kittell; D. Shane Stafford; Mark J. Kushner; Wayne C. Solomon

2005-01-01

294

Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2(a1Delta) produced in an electric discharge  

Microsoft Academic Search

Laser action at 1315 nm on the I(2P1\\/2)-->I(2P3\\/2) transition of atomic iodine is conventionally obtained by a near-resonant energy transfer from O2(a1Delta) which is produced using wet-solution chemistry. The difficulties in chemically producing O2(a1Delta) has motivated investigations into purely gas phase methods to produce O2(a1Delta) using low-pressure electric discharges. In this letter, we report on the demonstration of a continuous-wave

David L. Carroll; Joseph T. Verdeyen; Darren M. King; Joseph W. Zimmerman; Julia K. Laystrom; Brian S. Woodard; Gabriel F. Benavides; Kirk Kittell; D. Shane Stafford; Mark J. Kushner; Wayne C. Solomon

2005-01-01

295

Planar Laser-Induced Iodine Fluorescence Measurements in Rarefied Hypersonic Flow  

NASA Technical Reports Server (NTRS)

A planar laser-induced fluorescence (PLIF) technique is discussed and applied to measurement of time-averaged values of velocity and temperature in an I(sub 2)-seeded N(sub 2) hypersonic free jet facility. Using this technique, a low temperature, non-reacting, hypersonic flow over a simplified model of a reaction control system (RCS) was investigated. Data are presented of rarefied Mach 12 flow over a sharp leading edge flat plate at zero incidence, both with and without an interacting jet issuing from a nozzle built into the plate. The velocity profile in the boundary layer on the plate was resolved. The slip velocity along the plate, extrapolated from the velocity profile data, varied from nearly 100% down to 10% of the freestream value. These measurements are compared with results of a DSMC solution. The velocity variation along the centerline of a jet issuing from the plate was measured and found to match closely with the correlation of Ashkenas and Sherman. The velocity variation in the oblique shock terminating the jet was resolved sufficiently to measure the shock wave thickness.

Cecil, Eric; McDaniel, James C.

2005-01-01

296

Comparing modeling and measurements of the output power in chemical oxygen-iodine lasers: A stringent test of I2 dissociation mechanisms  

NASA Astrophysics Data System (ADS)

A parametric study of the output power of supersonic chemical oxygen-iodine lasers (COILs) is carried out, applying a kinetic-fluid dynamics model calculations as well as an analytical model and comparing the results to experimental studies. The I2 dissociation mechanism recently suggested by Azyazov et al. [J. Chem. Phys. 130, 104306 (2009)], which was previously used for comparison of model calculations to measurements of the small signal gain [K. Waichman et al., J. Appl. Phys. 106, 063108 (2009)], is applied here for a similar, but more sensitive, comparison of the laser output power. The dependence of the power on iodine flow rate and on mirror transmission is studied for low and high pressure COILs, respectively. Good agreement between the calculated and measured power is obtained for both low and high pressure COILs only when the processes suggested by Azyazov et al. are included in the calculations. This is different from the situation for the gain where for high pressure COILs, the calculated values were insensitive to the assumed dissociation mechanism, although for low pressure the measurements were reproduced only by applying the Azyazov et al. mechanism. We believe that the results of the present work strongly support the application of this mechanism for modeling the COIL operation.

Waichman, K.; Barmashenko, B. D.; Rosenwaks, S.

2010-08-01

297

Design investigation of solar powered lasers for space applications  

NASA Technical Reports Server (NTRS)

The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the lasant. Efficiencies in the range of 10 to 20 percent are projected for these indirect optically pumped lasers.

Taussig, R.; Bruzzone, C.; Quimby, D.; Nelson, L.; Christiansen, W.; Neice, S.; Cassady, P.; Pindroh, A.

1979-01-01

298

Iodine Deficiency  

MedlinePLUS

... enlargement of the thyroid (goiter – see Goiter brochure ), hypothyroidism (see Hypothyroidism brochure ) and to mental retardation in infants and ... when lying down, and difficulty swallowing and breathing. Hypothyroidism – As the body’s iodine levels fall, hypothyroidism may ...

299

Iodine in diet  

MedlinePLUS

Diet - iodine ... Many months of iodine deficiency in a person's diet may cause goiter or hypothyroidism . Without enough iodine, ... and older children. Getting enough iodine in the diet may prevent a form of physical and intellectual ...

300

The development and deployment of a ground-based, laser-induced fluorescence instrument for the in situ detection of iodine monoxide radicals  

SciTech Connect

High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer. Of particular interest are the roles IO plays in the formation of new particles in coastal marine environments and in depletion episodes of ozone and mercury in the Arctic polar spring. This paper describes a ground-based instrument that measures IO at mixing ratios less than one part in 10{sup 12}. The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A{sup 2}?{sub 3/2} (v{sup ?} = 2) ? X{sup 2}?{sub 3/2} (v{sup ?} = 0) transition of IO near 445 nm. The laser light is produced by a solid-state, Nd:YAG-pumped Ti:Sapphire laser at 5 kHz repetition rate. The laser-induced fluorescence instrument performs reliably with very high signal-to-noise ratios (>10) achieved in short integration times (<1 min). The observations from a validation deployment to the Shoals Marine Lab on Appledore Island, ME are presented and are broadly consistent with in situ observations from European Coastal Sites. Mixing ratios ranged from the instrumental detection limit (<1 pptv) to 10 pptv. These data represent the first in situ point measurements of IO in North America.

Thurlow, M. E., E-mail: thurlow@huarp.harvard.edu; Hannun, R. A.; Lapson, L. B.; Anderson, J. G. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States)] [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Co, D. T. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Argonne-Northwestern Solar Energy Research Center and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113 (United States); O'Brien, A. S. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544 (United States); Hanisco, T. F. [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 (United States); NASA Goddard Space Flight Center, Code 614, Greenbelt, Maryland 20771 (United States)

2014-04-15

301

Broadband laser amplifier based on gas-phase dimer molecules pumped by the Sun.  

PubMed

We report the design and experimental realization of a solar-pumped dimer gas-laser amplifier. The amplifying medium is Te(2) gas, which is capable of amplifying laser signals over a broad spectral range. A gain of 42% was measured at a wavelength of 632.8 nm. We also present studies of the material characteristics and a brief review of the study of other candidate materials for solar pumping. PMID:18049599

Pe'er, I; Vishnevitsky, I; Naftali, N; Yogev, A

2001-09-01

302

Sensitized energy transfer for organic solar cells, optical solar concentrators, and solar pumped lasers  

E-print Network

The separation of chromophore absorption and excitonic processes, such as singlet exciton fission and photoluminescence, offers several advantages to the design of organic solar cells and luminescent solar concentrators ...

Reusswig, Philip David

2014-01-01

303

Catalytic enhancement of singlet oxygen production and optical gain in electric discharge oxygen-iodine laser systems  

Microsoft Academic Search

We are investigating catalytically enhanced production of singlet oxygen, O2(a1▵g), observed by reaction of O2\\/He discharge effluents over an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We have previously reported a two-fold increase in the O2(a) yields by this process, and corresponding enhancement of I(2P1\\/2) excitation and small-signal gain upon injection of I2 and NO2.

Seonkyung Lee; Wilson T. Rawlins; Adam J. Hicks; Ian M. Konen; Emily P. Plumb; Steven J. Davis

2011-01-01

304

Direct Measurement of O(2)(a(1)D) and O(2)(X(3)?) in Chemical Oxygen-Iodine Lasers with use of Spontaneous Raman Imaging.  

PubMed

A spontaneous Raman imaging system (SRIS) has been developed that can monitor chemical oxygen-iodine laser (COIL) singlet oxygen generator (SOG) performance in real time. This system permits one to monitor directly the SOG performance by measuring O(2)(a(1)D) and O(2)(X(3)?) simultaneously with a single intensified CCD array at the exit of an imaging monochromator. We present the results from tests conducted on a 0.25-mol SOG using a prototype Raman system. Performance and validation of a highly sensitive SRIS that was designed and built specifically for SOG diagnostics are discussed. Detection and possible interferences of other species relevant to COIL devices such as I(2) and Cl(2) are investigated. PMID:18268680

Gylys, V T; Rubin, L F

1998-02-20

305

Experimental study on supersonic all gas-phase iodine laser driven by NF3/D2/DCl/CF3I combustion  

NASA Astrophysics Data System (ADS)

A supersonic all gas-phase iodine laser driven by NF3/D2/DCl/CF3I combustion has been experimentally studied. the gain signals of I(2P3/2,F=4)<-- I(2P1/2,F=3) at 1315.246nm and I(2P3/2,F=3)<-- I(2P1/2,F=3) at 1315.222nm were observed with an intensity of 3x10-5cm-1 and 1x10-5cm-1 respectively. The small signal gain of I(2P3/2,F=4)<-- I(2P1/2,F=3) at different location relative to HN3 injector along the flow direction also was obtained. The experimental results indicate that the AGIL driven by NF3/D2/DCl/CF3I combustion is feasible.

Tang, Shukai; Duo, Liping; Yu, Haijun; Sang, Fengting; Jin, Yuqi

2012-01-01

306

Frequency-doubled pulsed chemical oxygen-iodine laser as an efficient pump source for high-power solid state lasers  

Microsoft Academic Search

Output laser parameters are enhanced significantly by using laser pumping. An excellent example is usage of laser diodes for solid-state laser pumping. Although there are permanent advances towards development of this technique, its application for laser systems of more than 100 J output requires time, significant effort and expense. I propose another pumping source based on a rather simple and

P. G. Kryukov

1995-01-01

307

Numerical simulation of supersonic-flow chemical oxygen-iodine laser with high Mach-number ramp-nozzle array  

NASA Astrophysics Data System (ADS)

The characteristics of mixing between two flows of oxygen and iodine, having different Mach numbers, are numerically examined with the intention of improving the pressure recovery of the exhaust gas of supersonic-flow COIL. Supersonic, parallel mixing system with ramp nozzle array is adopted. The nozzle array has unevenly-piled shape, which is expected to generate vortices and enhance mixing. Three-dimensional, compressible Navier-Stokes equations are solved by means of full-implicit finite difference method. The flow fields are calculated for three types of nozzles, namely, ramp nozzle, symmetric ramp nozzle, and symmetric swept-ramp nozzle. The results indicate that the symmetric swept-ramp nozzle has the best performance.

Suzuki, Masataro; Ito, Kenichi; Masuda, Wataru

2005-03-01

308

Advanced Gas Laser Experiments and Modeling D. L. Carroll1  

E-print Network

chemical and gas laser systems. Among these are the electric oxygen-iodine laser (ElectricOIL), the diode driven gas phase characteristics. II. The Electric Oxygen-Iodine Laser The electrically driven oxygen-iodine the discharge flow, (iii) the iodine injectors and injection region, (iv) the nozzle and laser cavity extraction

Carroll, David L.

309

COIL with supersonic injection of chemically produced atomic iodine  

NASA Astrophysics Data System (ADS)

An advanced Chemical Oxygen-Iodine Laser (COIL) using the chemical generation of atomic iodine was studied. Atomic iodine is produced by the reaction of atomic chlorine with hydrogen iodide (HI) in two separated reactors tightly attached to the supersonic laser cavity. The iodine-contained mixture is injected to the flow of singlet oxygen by means of the supersonic orifices located 5 mm downstream the nozzle throat. The atomic iodine number density in the laser cavity up to 1.2 x 10 15 cm -3 and a small-signal gain up to 0.35 %/cm were achieved. An rather high quenching of singlet oxygen by HI caused that the attained laser power was low. The results of small signal gain and the laser power are compared with the previous system including the mixing of reactants upstream the nozzle throat.

Jirásek, Vít; Špalek, Otomar; ?enský, Miroslav; Kodymová, Jarmila; Picková, Irena; Jakubec, Ivo

2007-05-01

310

ACTIVE MEDIA: Analytic study of the chain dark decomposition reaction of iodides — atomic iodine donors — in the active medium of a pulsed chemical oxygen—iodine laser: 1. Criteria for the development of the branching chain dark decomposition reaction of iodides  

NASA Astrophysics Data System (ADS)

The scheme of chemical processes proceeding in the active medium of a pulsed chemical oxygen—iodine laser (COIL) is analysed. Based on the analysis performed, the complete system of differential equations corresponding to this scheme is replaced by a simplified system of equations describing in dimensionless variables the chain dark decomposition of iodides — atomic iodine donors, in the COIL active medium. The procedure solving this system is described, the basic parameters determining the development of the chain reaction are found and its specific time intervals are determined. The initial stage of the reaction is analysed and criteria for the development of the branching chain decomposition reaction of iodide in the COIL active medium are determined.

Andreeva, Tamara L.; Kuznetsova, S. V.; Maslov, Aleksandr I.; Sorokin, Vadim N.

2009-02-01

311

Design and operation of a supersonic flow cavity for a non-self-sustained electric discharge pumped oxygen iodine laser  

Microsoft Academic Search

The paper presents results of a high-pressure, non-self-sustained crossed discharge-M = 3 supersonic laser cavity operation. A stable and diffuse pulser-sustainer discharge in O2-He flows is generated at pressures of up to P0 = 120 Torr and discharge powers of up to 2.1 kW. The reduced electric field in the dc sustainer discharge ranges from 0.6 × 10-16 to 1.2

A. Hicks; S. Tirupathi; N. Jiang; Yu Utkin; W. R. Lempert; J. W. Rich; I. V. Adamovich

2007-01-01

312

The electric oxygen-iodine laser: chemical kinetics of O II(a1?) production and I(2 P 1/2) excitation in microwave discharge systems  

NASA Astrophysics Data System (ADS)

Generation of singlet oxygen metastables, O II(a1?), in an electric discharge plasma offers the potential for development of compact electric oxygen-iodine laser (EOIL) systems using a recyclable, all-gas-phase medium. The primary technical challenge for this concept is to develop a high-power, scalable electric discharge configuration that can produce high yields and flow rates of O II(a) to support I(2P 1/2->2P 3/2) lasing at high output power. This paper discusses the chemical kinetics of the generation of O II(a) and the excitation of I(2P 1/2) in discharge-flow reactors using microwave discharges at low power, 40-120 W, and moderate power, 1-2 kW. The relatively high E/N of the microwave discharge, coupled with the dilution of O II with Ar and/or He, leads to increased O II(a) production rates, resulting in O II(a) yields in the range 20-40%. At elevated power, the optimum O II(a) yield occurs at higher total flow rates, resulting in O II(a) flow rates as large as 1 mmole/s (~100 W of O II(a) in the flow) for 1 kW discharge power. We perform the reacting flow measurements using a comprehensive suite of optical emission and absorption diagnostics to monitor the absolute concentrations of O II(a), O II(b), O( 3P), I II, I(2P 3/2), I(2P 1/2), small-signal gain, and temperature. These measurements constrain the kinetics model of the system, and reveal the existence of new chemical loss mechanisms related to atomic oxygen. The results for O II(a) production at 1 kW have intriguing implications for the scaling of EOIL systems to high power.

Rawlins, W. T.; Lee, S.; Kessler, W. J.; Oakes, D. B.; Piper, L. G.; Davis, S. J.

2006-02-01

313

Aspirin and fraxiparine in the prevention of laser induced thrombosis in the presence of iodinated contrast media.  

PubMed

The purpose of this study was to investigate the thromboembolic properties of ionic and nonionic contrast media in rats pretreated with aspirin and/or fraxiparine using an experimental model of laser induced thrombosis in the mesenteric microvessels of 17 groups of five male Wistar rats each. Two ionic (ioxaglate and diatrizoate) and two nonionic contrast media (iopamidol and iohexol), alone or associated with antithrombotic drugs (aspirin and/or fraxiparine) were studied. To evaluate the effects of these substances in this model, the number of laser beams needed to induce platelet thrombus formation, the number of emboli detached from the thrombus and the duration of embolization were quantified. Platelet aggregation induced by ADP, induced hemorrhagic time (IHT) and haemoglobin loss level were also determined. Both contrast media injected at 3 ml/kg caused a significant increase in the number of emboli and the duration of embolization (p<0.05). Pretreatment with aspirin and/or fraxiparine in the presence of ionic contrast media showed antithrombotic activities equal to those obtained when they were tested alone (p<0.05), while in the presence of nonionic contrast media, these drugs only neutralised the prothrombotic effects. There were no differences with the NaCl treated group (p>0.05). The ionic contrast media, and to a lesser extent the nonionic contrast medium: iohexol, inhibited platelet aggregation, while iopamidol behaved as an activator. The antithrombotic drugs tested in this study prevent the prothrombotic activities of contrast media therefore suggesting their use before radiographic procedures. PMID:9806362

Aguejouf, O; Belougne Malfatti, E; Doutremepuich, F; Doutremepuich, C

1998-11-01

314

O{sub 2}(a {sup 1}DELTA{sub g}) production in flowing Ar-O{sub 2} surface-wave microwave discharges: Possible use for oxygen-iodine laser excitation  

SciTech Connect

Herein we present the calculations conducted on an Ar-O{sub 2} surface-wave microwave discharge and its afterglow, and show that this system can be effectively used for the oxygen-iodine laser excitation. It is demonstrated that at pressures higher than 10 mbar O{sub 2}(a) yields higher than the threshold yield required for positive gain can be achieved along the afterglow. Additionally, the density of O({sup 3}P) atoms, which can quench the I({sup 2}P{sub 1/2}) excited state, can be tuned to the desired level.

Guerra, Vasco [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa (Portugal); Kutasi, Kinga [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Sa, Paulo A. [Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, 1049-001 Lisboa, Portugal and Departamento de Engenharia Fisica, Faculdade de Engenharia da Universidade do Porto, 4200-465 Porto (Portugal)

2010-02-15

315

Modelling coil with iodine atoms produced by pulsed electric discharge  

Microsoft Academic Search

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 the 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

A. P. Napartovich; I. V. Kochetov; N. P. Vagin; N. N. Yuryshev

2007-01-01

316

Consequences of excess iodine  

PubMed Central

Iodine is a micronutrient that is essential for the production of thyroid hormones. The primary source of iodine is the diet via consumption of foods that have been fortified with iodine, including salt, dairy products and bread, or that are naturally abundant in the micronutrient, such as seafood. Recommended daily iodine intake is 150 ?g in adults who are not pregnant or lactating. Ingestion of iodine or exposure above this threshold is generally well-tolerated. However, in certain susceptible individuals, including those with pre-existing thyroid disease, the elderly, fetuses and neonates, or patients with other risk factors, the risk of developing iodine-induced thyroid dysfunction might be increased. Hypothyroidism or hyperthyroidism as a result of supraphysiologic iodine exposure might be either subclinical or overt, and the source of the excess iodine might not be readily apparent. PMID:24342882

Leung, Angela M.; Braverman, Lewis E.

2014-01-01

317

Oxygen-iodine active medium with external production of iodine in a DC glow discharge  

NASA Astrophysics Data System (ADS)

Experiments with a flow cell apparatus imitating conditions of oxygen-iodine laser, equipped with a chemical jet singlet oxygen generator and an electric discharge iodine generator have been performed. I II and CH 3I in the flow of Ar were used as atomic iodine precursors. The distributions of the electronically excited species along the flow were examined detecting their optical emissions. A straightforward comparison of two methods of oxygen-iodine medium production - conventional, by means of I II dissociation in the singlet oxygen flow and with iodine atoms produced externally in the electric discharge - was performed. It was found that stored electron energy lifetime had been about 30% longer, when iodine was produced from CH 3I in the discharge, compared to the conventional I II dissociation in the singlet oxygen flow. It was observed that maximums of the I(2P 1/2) and I II(B) concentrations had shifted to the nozzle plane, when I II in Ar carrier was subjected to the glow discharge, pointing to a nearly twofold increase in the I II dissociation rate. Contrary to the known results for low iodine and singlet oxygen concentrations, squared dependence of the amplitude of the I II(B) luminescence maximum with I(2P 1/2) concentration was observed in the dissociation region for both methods of iodine production.

Mikheyev, Pavel A.; Azyazov, Valeriy N.; Mezhenin, Adrew V.; Ufimtsev, Nikolay I.; Shepelenko, Alexander A.; Voronov, Anatoly I.; Kupryaev, Nikolay V.; Pichugin, Sergey Yu.; Vorobyov, Mikhail V.

2007-05-01

318

The {sup 2}P{sub 1/2} {yields} {sup 2}P{sub 3/2} laser transition in atomic iodine and the problem of search for signals from extraterrestrial intelligence  

SciTech Connect

It is proposed to search for signals from extraterrestrial intelligence (ETI) at a wavelength of 1.315 {mu}m of the laser {sup 2}P{sub 1/2} {yields} {sup 2}P{sub 3/2} transition in the atomic iodine, which can be used for this purpose as the natural frequency reference. The search at this wavelength is promising because active quantum filters (AQFs) with the quantum sensitivity limit have been developed for this wavelength, which are capable of receiving laser signals, consisting of only a few photons, against the background of emission from a star under study. In addition, high-power iodine lasers emitting diffraction-limited radiation at 1.315 {mu}m have been created, which highly developed ETI also can have. If a ETI sends in our direction a diffraction-limited 10-ns, 1-kJ laser pulse with the beam diameter of 10 m, a receiver with an AQF mounted on a ten-meter extra-atmospheric optical telescope can detect this signal at a distance of up to 300 light years, irrespective of the ETI position on the celestial sphere. The realisation of the projects for manufacturing optical telescopes of diameter 30 m will increase the research range up to 2700 light years. A weak absorption of the 1.315-{mu}m radiation in the Earth atmosphere (the signal is attenuated by less than 20%) allows the search for ETI signals by using ground telescopes equipped with adaptive optical systems. (laser applications and other topics in quantum electronics)

Kutaev, Yu F; Mankevich, S K ['Astrofizika' Research and Production Association (Russian Federation); Nosach, O Yu; Orlov, E P [P.N. Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2007-07-31

319

Surface-catalyzed singlet oxygen production on iodine oxide films  

NASA Astrophysics Data System (ADS)

Enhanced production of singlet oxygen, O2(a1?g), was observed by reaction of O2/He discharge effluents on an iodine oxide film surface in a microwave discharge-flow reactor at 320 K. We observed a two-fold increase in the O2(a) yields over discharge-generated amounts for non-catalytic conditions. The iodine oxide surface appears to catalyze the heterogeneous reaction to form O2(a) with high collision efficiency. The observed catalytic effect could significantly benefit the development of electrically driven oxygen-iodine laser systems, and may also have implications for the chemistry of atmospheric iodine oxide aerosol.

Lee, Seonkyung; Terry Rawlins, W.; Davis, Steven J.

2009-02-01

320

Modelling of COIL lasers  

Microsoft Academic Search

The modelling of chemical oxygen iodine lasers (COIL's) is discussed. A qualitative description of the system hardware elements and the major physical processes occurring in the laser is presented. Next, a steady one-dimensional model of the oxygen iodine laser system which includes the effects of area change, heat transfer, friction, mass injection and removal, changes in molecular weight and specific

D. H. Lewis Jr.; C. W. Clendening

1982-01-01

321

COIL operation with iodine atoms generated in a glow discharge  

NASA Astrophysics Data System (ADS)

Experiments were carried out with a subsonic chemical oxygen-iodine laser (COIL), equipped with an electric discharge generator of iodine atoms. CH3I entrained in a carrier flow of Ar was used as atomic iodine precursor. About 50% of iodine contained in CH3I molecules was extracted in the generator. Up to 3.5% of electric power loaded into the discharge was spent on CH3I dissociation. A straightforward comparison of COIL performance for two cases - conventional, when I2 was injected in the singlet oxygen flow and when iodine atoms produced externally together with other discharge products were injected - was made. In the latter case nearly four times increase in output power was observed.

Mikheyev, P. A.; Zagidullin, M. V.; Ufimtsev, N. I.; Khvatov, N. A.; Voronov, A. I.; Azyazov, V. N.

2010-11-01

322

Iodine generator for reclaimed water purification  

NASA Technical Reports Server (NTRS)

The system disclosed is for controlling the iodine level in a water supply in a spacecraft. It includes an iodine accumulator which stores crystalline iodine, an electrochemical valve to control the input of iodine to the drinking water and an iodine dispenser. A pump dispenses fluid through the iodine dispenser and an iodine sensor to a potable water tank storage. The iodine sensor electronically detects the iodine level in the water, and through electronic means, produces a correction current control. The correction current control operates the electro-chemical iodine valve to release iodine from the iodine accumulator into the iodine dispenser.

Wynveen, R. A.; Powell, J. D.; Schubert, F. H. (inventors)

1977-01-01

323

Recent results of iodine and water diagnostics in supersonic COIL  

Microsoft Academic Search

Water vapor measurements at DLRs supersonic chemical oxygen iodine laser (COIL) have been carried out applying a tunable diode laser system. During a typical hot flow of 8 s, the water molar flow rate increases from 35 mmol\\/s to 85 mmol\\/s. Simultaneous measurements in the subsonic and supersonic region showed that about 10 percent of water in front of the

Frank R. Duschek; Karin M. Gruenewald; Willy L. Bohn

2000-01-01

324

Iodine in Texas Soils.  

E-print Network

LT BKAKY. A Ik M COLLEGE, TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 579 OCTOBER 1939 DIVISION OF CHEMISTRY IODINE IN TEXAS SOILS AGRICULTURAL AND MECHANICAL COLLEGE....8, Blackland Prairies 5.8, Basins and Mountains 6.6, Rolling Plains 7.1, Rio Grande Plain 8.0, Grand Prairie 10.2, and Edwards Plateau 11.3 parts per million. Heavy textured soils con- tained more iodine than light textured soils. A high iodine content...

Fraps, G. S. (George Stronach); Fudge, J. F. (Joseph Franklin)

1939-01-01

325

Spaceborne Photonics Institute  

NASA Technical Reports Server (NTRS)

This report describes in chronological detail the development of the Spaceborne Photonics Institute as a sustained research effort at Hampton University in the area of optical physics. This provided the research expertise to initiate a PhD program in Physics. Research was carried out in the areas of: (1) modelling of spaceborne solid state laser systems; (2) amplified spontaneous emission in solar pumped iodine lasers; (3) closely simulated AM0 CW solar pumped iodine laser and repeatedly short pulsed iodine laser oscillator; (4) a materials spectroscopy and growth program; and (5) laser induced fluorescence and atomic and molecular spectroscopy.

Venable, D. D.; Farrukh, U. O.; Han, K. S.; Hwang, I. H.; Jalufka, N. W.; Lowe, C. W.; Tabibi, B. M.; Lee, C. J.; Lyons, D.; Maclin, A.

1994-01-01

326

Radioactive iodine uptake  

MedlinePLUS

... the testing center so that the amount of radioactivity in the thyroid gland can be measured. This ... The amount of radioactivity is very small, and there have been no documented side effects. The amount of iodine used is less than ...

327

Iodine and Pregnancy  

MedlinePLUS

... levels of iodine in my system make it harder for me to become pregnant? Your body uses ... of thyroid hormone (called hypothyroidism) may have a harder time getting pregnant. Therefore, it is important to ...

328

Breastmilk Iodine Concentrations Following Acute Dietary Iodine Intake  

PubMed Central

Background Breastmilk iodine levels may vary temporally in response to recent changes in dietary iodine intake. We assessed the effect of and time to peak breastmilk iodine levels after potassium iodine ingestion, which has never been studied and is important toward interpretation of studies of breastmilk iodine measurements. Methods Sixteen healthy lactating Boston-area women with no known thyroid disease were each given 600??g oral potassium iodide (KI) (456??g iodine) after an overnight fast. Iodine was measured in breastmilk and urine at baseline and hourly for 8 hours following iodine intake. All dietary iodine ingested during the study period was also measured. Results Mean age of mothers was 30.2±4.1 (SD) years. Median (interquartile range [IQR]) baseline breastmilk and urine iodine levels were 45.5??g/L (IQR 34.5–169.0) and 67.5??g/L (IQR 57.5–140.0), respectively. Following 600??g KI administration, median increase in breastmilk iodine levels above baseline was 280.5??g/L (IQR 71.5–338.0), and median peak breastmilk iodine concentration was 354??g/L (IQR 315–495). Median time to peak breastmilk iodine levels following KI administration was 6 hours (IQR 5–7). Dietary iodine sources provided an additional 36–685??g iodine intake during the 8-hour study. Conclusions Following ingestion of 600??g KI, there is a measurable rise in breastmilk iodine concentrations, with peak levels occurring at 6 hours. These findings strongly suggest that breastmilk iodine concentrations should be interpreted in relation to recent iodine intake. PMID:23050787

Braverman, Lewis E.; He, Xuemei; Heeren, Timothy; Pearce, Elizabeth N.

2012-01-01

329

Deep well solar pump  

SciTech Connect

This patent describes, in a pump having a source of gas under pressure, and a gas operated pump, a mechanism periodically injecting gas from the source of gas into the gas operated pump. It comprises: a long period pendulum turning towards a first position by gravity, an injection valve connected between the source of gas under pressure and the gas operated pump, a linkage between the pendulum and the injection valve. The linkage opening the injection valve when the pendulum is in the first position, an impulse tube connected between the injection valve and the gas operated pump, a member having a surface adjacent to the first position of the pendulum, and an elastic impulse bladder connected to the impulse tube adjacent to the surface so that inflation of the impulse bladder on the opening of the injection valve forces the impulse bladder against the pendulum urging the pendulum against the force of gravity toward a second position.

Vanek, J.

1990-02-06

330

AlGaAs-GaAs quantum-well lasers for direct solar photopumping  

NASA Technical Reports Server (NTRS)

The paper theoretically examines the solar power requirements for low-threshold AlGaAs-GaAs quantum-well lasers directly photopumped by focused sunlight. A model of separate-confinement quantum-well-heterostructure (SCQWH) lasers was developed, which explicitly treats absorption and transport phenomena relevant to solar pumping. The model was used to identify separate-confinement single-quantum-well laser structures which should operate at photoexcitation intensities of less than 10,000 suns.

Unnikrishnan, Sreenath; Anderson, Neal G.

1991-01-01

331

Comparison of laser models  

NASA Technical Reports Server (NTRS)

Progress on the comparison of laser models is reported. Equations for an oscillatory model and a nonoscillatory model for the simulation of iodine laser operation are solved. Reaction rate coefficients used in both models are listed. Currently there are four models for the simulation of iodine laser operation are solved. Reaction rate coefficients used in both models are listed. Currently there are four models for the simulation of an iodine laser. They are: (1) a time dependent model; (2) a quasi-steady state model; (3) a noncompressible model; and (4) a compressible flow laser model. Current research is being directed toward: (1) parameter studies using the compressible flow laser model; (2) development of a two-pass amplifier model; and (3) solving a system of equations describing operation of the high powered iodine MOPA (master oscillator power amplifier).

Heinbockel, John H.

1989-01-01

332

Experimental modeling the active medium of a pulsed DOIL with volume generation of iodine atoms  

NASA Astrophysics Data System (ADS)

The active medium of a pulsed DOIL with volume generation of iodine atoms was experimentally simulated using the chemical generator of singlet oxygen and MW discharge to understand the feasibility of a pulsed oxygen-iodine laser with electrical generator of singlet oxygen.

Yuryshev, N. N.; Vagin, N. P.

2008-10-01

333

Aqueous chemistry of iodine  

SciTech Connect

The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H/sub 3/BO/sub 3/ at temperatures up to 150/sup 0/C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO/sub 3//sup -/ + 2I/sup -/ + 3H/sup +/, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >10/sup 4/ has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs.

Toth, L.M.; Pannell, K.D.; Kirkland, O.L.

1984-01-01

334

Adsorption of iodine from COIL waste gas on soaked coal-based activated carbon  

NASA Astrophysics Data System (ADS)

The chemical oxygen–iodine laser (COIL) has wide application prospects in military, industrial and medical treatment fields as a second generation gas chemical laser to follow the first HF/DF chemical laser. However, a COIL releases large amounts of gas, such as helium, oxygen, chlorine and iodine. Chlorides have a serious corrosive effect on the system, especially iodine vapor crystallization, which seriously endangers the normal use of vacuum systems, and radioactive methyl iodide, which is hazardous to operators and pollutes the environment. The use of soaked coal-based activated carbon as an adsorbent for removing methyl iodine is proposed, while it is proposed that coal-based activated carbon is an effective adsorbent for removing stable iodine. The research conducted in this work shows that iodine residues are less than 0.5 ?g ml?1 after the adsorption treatment and the decontamination factor of the coal-based activated carbon for removing stable iodine is more than 1000. Using this method can achieve the purpose of removing harmful iodine, satisfy the requirements for engineering applications, and also be applied to other nuclear power plant flue gas treatments.

Zhou, Junbo; Hao, Shan; Gao, Liping

2014-04-01

335

Analysis of rate constants for oxygen-iodine active media  

Microsoft Academic Search

To work out specific laser system, to optimize their operating conditions it is necessary to have a complete description of the kinetic processes in active media and exact values of the reactions rate constants. The detailed study of process kinetics in COIL were discussed in a number of papers and a review on the rate constants at oxygen-iodine media has

Yu. A. Kulagin; V. N. Yarygina

1996-01-01

336

An iodine hypersonic wind tunnel for the study of nonequilibrium reacting flows  

NASA Technical Reports Server (NTRS)

A pilot scale hypersonic wind tunnel operating on pure iodine vapor has been designed and tested. The wind tunnel operates intermittently with a run phase lasting approximately 20 minutes. Successful recirculation of the iodine used during the run phase has been achieved but can be improved. Relevant issues regarding the full scale facility's design and operation, and the use of iodine as a working gas are discussed. Continuous wave laser induced fluorescence was used to monitor number densities within the plume flowfield, while pulsed laser induced fluorescence was used in an initial attempt to measure vibrational energy state population distributions. Preliminary nozzle flow calculations based on finite rate chemistry are presented.

Pham-Van-diep, G. C.; Muntz, E. P.; Weaver, D. P.; Dewitt, T. G.; Bradley, M. K.; Erwin, D. A.; Kunc, J. A.

1992-01-01

337

Criteria for the evaluation of laser solar energy converter systems  

NASA Technical Reports Server (NTRS)

Assuming that a parabolic insolation-collection mirror-based solar pumped laser has a collector and heat emitter whose weights are proportional to their areas, and that the weight of the laser is negligible by comparison, the output power/unit weight can be expressed in terms of the efficiencies and working temperatures of the system. This ratio appears to be several times higher for an IBr laser than for one operating on C3F7I, because the solar utilization efficiency is greater for the former despite its lower working temperature.

Harries, W. L.

1985-01-01

338

Optical frequency references for laser interferometry  

NASA Astrophysics Data System (ADS)

Optical frequency references for laser standards based on molecular iodine absorption cells represent one of the most used tool for frequency stabilization of lasers operating in a visible spectral range. In the industry oriented laser measurements and similar laser interferometry applications performed at atmospheric conditions, a refractive index of air plays a role of main uncertainty contributor. In these cases there is no need to use technologically complicated and expensive iodine references made of pure fused silica with precise pressure control of absorpbing media. A set of iodine cells made of borosilicate glass was filled with certain amount of absorbing media to define the saturation point of iodine inside. A combination of these two approaches (pyrex material and controlled saturation pressure of iodine) allows us to simplify the laser stabilization setup (there is no need of additional iodine pressure level control) and reduce the overall reference's costs with ensuring of sufficient frequency stability of the system at the same time. Spectral properties of manufactured cells were tested by hyperfine transitions linewidth measurement and comparison with results from traditional fused silica cells was done to investigate the long-term iodine purity inside the references. As the transitions linewidth method shows a very high sensitivity to iodine purity level, this method is proposed to be an alternative approach in investigation of contamination in iodine absorption cells where traditionally used techniques - laser induced fluorescence (LIF) and absolute frequency shifts measurement - can not be used.

Hrabina, Jan; Šarbort, Martin; Acef, Ouali; du Burck, Frédéric; Chiodo, Nicola; ?íp, Ond?ej; Lazar, Josef

2015-01-01

339

IEEE JOURNAL OF QUANTUM ELECTRONICS, VOL. 41, NO. 10, OCTOBER 2005 1309 Studies of CW Laser Oscillation on the 1315-nm  

E-print Network

. I. INTRODUCTION THE classic chemical oxygen­iodine laser (COIL) system [1] operates on the I P I P composed of two 99.995% reflective mirrors. Index Terms--Chemical oxygen­iodine laser (COIL), electric discharge oxygen­iodine laser, electriCOIL, radio frequency (RF) excitation of oxygen, singlet-delta oxygen

Carroll, David L.

340

Iodine Tagging Velocimetry in a Mach 10 Wake  

NASA Technical Reports Server (NTRS)

A variation on molecular tagging velocimetry (MTV) [1] designated iodine tagging velocimetry (ITV) is demonstrated. Molecular iodine is tagged by two-photon absorption using an Argon Fluoride (ArF) excimer laser. A single camera measures fluid displacement using atomic iodine emission at 206 nm. Two examples ofMTVfor cold-flowmeasurements areN2OMTV [2] and Femtosecond Laser Electronic Excitation Tagging [3]. These, like most MTV methods, are designed for atmospheric pressure applications. Neither can be implemented at the low pressures (0.1- 1 Torr) in typical hypersonic wakes. Of all the single-laser/singlecamera MTV approaches, only Nitric-Oxide Planar Laser Induced Fluorescence-based MTV [4] has been successfully demonstrated in a Mach 10 wake. Oxygen quenching limits transit times to 500 ns and accuracy to typically 30%. The present note describes the photophysics of the ITV method. Off-body velocimetry along a line is demonstrated in the aerothermodynamically important and experimentally challenging region of a hypersonic low-pressure near-wake in a Mach 10 air wind tunnel. Transit times up to 10 µs are demonstrated with conservative errors of 10%.

Balla, Robert Jeffrey

2013-01-01

341

Beverage iodine levels in Germany  

Microsoft Academic Search

Sales of iodized table salt (household use, bulk containers) have been flat in Germany since 1996\\/1997. Nevertheless, the\\u000a amount of iodide excreted with the urine has been steadily increasing in the German population since 1993. We investigated\\u000a the beverage iodine levels as possible source of the increased input of iodine into the food chain. No systematic studies\\u000a on this topic

Rainer Hampel; Julia Kairies

2009-01-01

342

Comparison of Molecular Iodine Spectral Properties at 514.7 and 532 nm Wavelengths  

NASA Astrophysics Data System (ADS)

We present results of investigation and comparison of spectral properties of molecular iodine transitions in the spectral region of 514.7 nm that are suitable for laser frequency stabilization and metrology of length. Eight Doppler-broadened transitions that were not studied in detail before were investigated with the help of frequency doubled Yb-doped fiber laser, and three of the most promising lines were studied in detail with prospect of using them in frequency stabilization of new laser standards. The spectral properties of hyperfine components (linewidths, signal-to-noise ratio) were compared with transitions that are well known and traditionally used for stabilization of frequency doubled Nd:YAG laser at the 532 nm region with the same molecular iodine absorption. The external frequency doubling arrangement with waveguide crystal and the Yb-doped fiber laser is also briefly described together with the observed effect of laser aging.

Hrabina, J.; Acef, O.; Burck, F. du; Chiodo, N.; Candela, Y.; Sarbort, M.; Hola, M.; Lazar, J.

2014-08-01

343

Iodine kinetics and effectiveness of stable iodine prophylaxis after intake of radioactive iodine: a review.  

PubMed

Ingestion of potassium iodide (KI) offers effective protection against irradiation of the thyroid after accidental exposure to radioactive iodine. This prophylaxis aims at rapidly obtaining maximal thyroid protection without adverse effects. This article reviews studies on iodine kinetics in humans and on the efficacy of KI in protecting the thyroid. In adults with normal thyroid function, ingestion of 100 mg of iodide just before exposure to radioactive iodine blocks at least 95% of the thyroid dose. If exposure persists after iodide ingestion (100 mg), the percentage of averted dose may decrease significantly. Daily ingestion of a dose of 15 mg of KI would then maintain the thyroid blockade at a level above 90%. The efficacy of iodide and the occurrence of antithyroid effects also depend on external and individual factors such as dietary iodine intake, thyroid function, and age. The KI dosage regimen should be adjusted for age at exposure. For the fetus, the newborn, children, and adolescents, the risk of radiation-induced thyroid cancer in case of accidental exposure to radioactive iodine justifies KI prophylaxis, despite the risk of hypothyroidism, especially in newborns. For the elderly, the benefits of KI may be lower than the risk of iodine-induced hyperthyroidism. PMID:11349833

Verger, P; Aurengo, A; Geoffroy, B; Le Guen, B

2001-04-01

344

High-Performance Water-Iodinating Cartridge  

NASA Technical Reports Server (NTRS)

High-performance cartridge contains bed of crystalline iodine iodinates water to near saturation in single pass. Cartridge includes stainless-steel housing equipped with inlet and outlet for water. Bed of iodine crystals divided into layers by polytetrafluoroethylene baffles. Holes made in baffles and positioned to maximize length of flow path through layers of iodine crystals. Resulting concentration of iodine biocidal; suppresses growth of microbes in stored water or disinfects contaminated equipment. Cartridge resists corrosion and can be stored wet. Reused several times before necessary to refill with fresh iodine crystals.

Sauer, Richard; Gibbons, Randall E.; Flanagan, David T.

1993-01-01

345

PVA-Iodine complexes: Formation, structure, and properties  

Microsoft Academic Search

The PVA-Iodine complexes formed in PVA films soaked in iodine-KI aqueous solutions without boric acid are studied from the structural point of view. First, iodine soaking at comparatively low iodine concentrations is studied where iodine sorption takes place mostly in the amorphous phase. There, our interest is concentrated on the following problems: What happens in PVA films during iodine soaking?

Keizo Miyasaka

346

Mixing in a supersonic COIL laser: influence of trip jets  

Microsoft Academic Search

We present an experimental study of a supersonic nozzle with supersonic iodine injection. This nozzle simulates Chemical Oxygen\\u000a Iodine Laser (COIL) flow conditions with non-reacting, cold flows. During the experiments, we used a laser sheet near 565 nm\\u000a to excite fluorescence in iodine, which we imaged with an intensified and gated CCD camera. We captured streamwise and semi-spanwise\\u000a (oblique-view) images, with

Carrie Noren; Peter Vorobieff; C. Randall Truman; Timothy J. Madden

2011-01-01

347

Chemical generation of atomic iodine for a COIL via atomic fluorine  

NASA Astrophysics Data System (ADS)

Results of experimental investigation of the chemical generation of atomic iodine for a Chemical Oxygen-Iodine Laser (COIL) are presented. The work was focused on the reaction system with atomic fluorine as an intermediate species produced by the chemical way from gaseous reactants. At the first step, atomic fluorine is produced in reaction of molecular fluorine with nitrogen oxide. Then F atoms react with gaseous hydrogen iodide producing atomic iodine. The efficiency of this two-step process was studied thoroughly in dependence on mixing conditions, flow rate of reacting gases and pressure in the reactor. The results obtained on the small-scale device under experimental conditions simulating pressure and flow conditions in a COIL show that atomic iodine is generated by this alternative, advantageous method with rather high concentrations sufficient for operation of the supersonic COIL.

Censky, Miroslav; Spalek, Otomar; Jirasek, Vit; Kodymova, Jarmila; Jakubec, Ivo

2004-05-01

348

Towards graphene iodide: iodination of graphite oxide  

NASA Astrophysics Data System (ADS)

Halogenated graphene derivatives are interesting owing to their outstanding physical and chemical properties. In this paper, we present various methods for the synthesis of iodinated graphene derivatives by the iodination of graphite oxides prepared according to either the Hummers or Hofmann method. Both graphite oxides were iodinated by iodine or hydroiodic acid under reflux or in an autoclave at elevated temperatures (240 °C) and pressures (over 100 bar). The influence of both graphite oxide precursors on the properties of resulting iodinated graphenes was investigated by various techniques, including SEM, SEM-EDS, high-resolution XPS, FTIR, STA, and Raman spectroscopy. Electrical resistivity was measured by a standard four point technique. In addition, the electrochemical properties were investigated by cyclic voltammetry. Although the iodinated graphenes were structurally similar, they had remarkably different concentrations of iodine. The most highly iodinated graphenes (iodine concentration above 30 wt%) exhibited relatively high C/O ratios, confirming high degrees of reduction. Iodine is incorporated in the form of covalent bonds to carbon atoms or as polyiodide anions non-covalently bonded through the charge transfer reaction with the graphene framework. Iodinated graphenes with such properties could be used as the starting material for further chemical modifications or as flame-retardant additives.Halogenated graphene derivatives are interesting owing to their outstanding physical and chemical properties. In this paper, we present various methods for the synthesis of iodinated graphene derivatives by the iodination of graphite oxides prepared according to either the Hummers or Hofmann method. Both graphite oxides were iodinated by iodine or hydroiodic acid under reflux or in an autoclave at elevated temperatures (240 °C) and pressures (over 100 bar). The influence of both graphite oxide precursors on the properties of resulting iodinated graphenes was investigated by various techniques, including SEM, SEM-EDS, high-resolution XPS, FTIR, STA, and Raman spectroscopy. Electrical resistivity was measured by a standard four point technique. In addition, the electrochemical properties were investigated by cyclic voltammetry. Although the iodinated graphenes were structurally similar, they had remarkably different concentrations of iodine. The most highly iodinated graphenes (iodine concentration above 30 wt%) exhibited relatively high C/O ratios, confirming high degrees of reduction. Iodine is incorporated in the form of covalent bonds to carbon atoms or as polyiodide anions non-covalently bonded through the charge transfer reaction with the graphene framework. Iodinated graphenes with such properties could be used as the starting material for further chemical modifications or as flame-retardant additives. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05219f

Šimek, Petr; Klímová, Kate?ina; Sedmidubský, David; Jankovský, Ond?ej; Pumera, Martin; Sofer, Zden?k

2014-11-01

349

Iodine spiking model for pressurized water reactors  

Microsoft Academic Search

An analytical treatment has been developed to describe the phenomenon of iodine spiking in the reactor coolant system during reactor shutdown with defective PWR fuel rods. The iodine mass inventory is conserved in the model. The mass transport of iodine in the fuel-to-clad gap is based on a diffusion mechanism, and a bulk-convective process during pressure and temperature transients. Iodine

B. J. Lewis; F. C. Iglesias; A. K. Postma; D. A. Steininger

1997-01-01

350

AIAA Plasmadynamics and Lasers Conference 5-8 June 2006, San Francisco, California  

E-print Network

system parameters. I. Introduction The classical chemical oxygen iodine laser (COIL) system1 employs to improvements in the hybrid Electric Oxygen-Iodine Laser (ElectricOIL) system that significantly increased37 th AIAA Plasmadynamics and Lasers Conference 5-8 June 2006, San Francisco, California AIAA 2006

Carroll, David L.

351

8, 79778008, 2008 Iodine speciation in  

E-print Network

ACPD 8, 7977­8008, 2008 Iodine speciation in rain, snow and aerosols B. S. Gilfedder et al. Title.0 License. Atmospheric Chemistry and Physics Discussions Iodine speciation in rain, snow and aerosols­8008, 2008 Iodine speciation in rain, snow and aerosols B. S. Gilfedder et al. Title Page Abstract

Boyer, Edmond

352

MARGINAL IODINE DEFICIENCY EXACERBATES PERCHLORATE THYROID TOXICITY.  

EPA Science Inventory

The environmental contaminant perchlorate disrupts thyroid homeostasis via inhibition of iodine uptake into the thyroid. This work tested whether iodine deficiency exacerbates the effects of perchlorate. Female 27 day-old LE rats were fed a custom iodine deficient diet with 0, 50...

353

Modelling coil with iodine atoms produced by pulsed electric discharge  

NASA Astrophysics Data System (ADS)

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 the 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 recalculated 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 are compared with experimental laser pulse waveforms. The conclusion is drawn about satisfactory agreement of the theory with the experiment. The mechanisms of iodine atoms production in the pulsed discharge are identified.

Napartovich, A. P.; Kochetov, I. V.; Vagin, N. P.; Yuryshev, N. N.

2007-05-01

354

Chemical lasers  

NASA Astrophysics Data System (ADS)

Fundamental properties of chemical lasers are presented and principal systems described in the nonclassified literature are reviewed. The fundamentals of the production of inversion in molecular gases by chemical processes are discussed. Iodine, HF, and DF lasers are described. The chemical reaction in the pulsed chemical HF and DF lasers is introduced by a transverse electrical discharge. In spite of the high dissociation energy and the electronegative properties which are unfavorable for a stable discharge regime, SF6 is used as fluorine source for safety reasons. The pulse energies reach 26 J in agreement with estimated values. The advantage of the present system is that is can also operate as CO2 laser in the TEA mode. The radiation of DF lasers is particularly interesting for military near-Earth applications because of its good transmission properties in the atmosphere.

Hugenschmidt, M.; Wey, J.

1985-05-01

355

Laser research at the Institute of Physics AS CR  

Microsoft Academic Search

Laser research at the Institute of Physics of the Academy of Sciences of Czech Republic covers both the development of advanced pulsed high-power laser systems, the iodine and x-ray in particular, and their applications in science and technology. The COIL laboratory with a small chemical oxygen-iodine laser facility participates in the worldwide effort to develop a competitive quasi-steady laser device

Karel Jungwirth

2005-01-01

356

Advanced prototype automated iodine monitor system  

NASA Technical Reports Server (NTRS)

The technique of detecting and measuring parts-per-million concentrations of aqueous iodine by direct spectrophotometric means is discussed, and development of a prototype Automated Iodine Monitoring/Controller System (AIMS) is elaborated. The present effort is directed primarily toward reducing the power requirement and the weight of the AIMS. Other objectives include determining the maximum concentration of iodine that can be dissolved in an alcohol solution, and in an aqueous potassium iodide solution. Also discussed are the effects of a no flow condition on iodine measurements and the effect of pH on spectrophotometric iodine determinations.

1976-01-01

357

Antimicrobial megaprostheses supported with iodine.  

PubMed

Deep infection associated with implants remains a serious complication of orthopedic surgery. We developed iodine coating for titanium implants. In this study, we performed a clinical trial of iodine-coated megaprostheses to evaluate its safety and antibacterial effects. Forty-seven patients with malignant bone tumor or pyogenic arthritis were treated using iodine-supported titanium megaprostheses between July 2008 and May 2013. The mean age was 53.6 years (range, 15-85 years). Twenty-six patients were males and 21 were females. The diagnoses included malignant bone tumor in 29 cases, infected total knee arthroplasty in 11 cases, chronic osteomyelitis due to pyogenic arthritis in six cases and loosening of total knee arthroplasty in one case. The iodine-supported implants used were 42 Kyocera Limb Salvage System and five KOBELCO K-MAX K-3. These megaprostheses were used to prevent infection in 21 patients, treat active infections in 26 patients. The mean follow-up period was 30.1 months (range, 8-50). Infection was prevented in 20 out of 21 patients. Only one patient had surgical site infection caused by Pseudomonas aeruginosa and was cured by intravenous administration of antibiotics alone without removal of the implant. In 26 treatment cases involving one- or two-stage revision surgery, infection subsided without any additional surgery. In all cases, there were no signs of infection at the time of the last follow-up. White blood cell and C-reactive protein levels returned to normal within four weeks after surgery. To confirm systemic effects of iodine, thyroid hormone levels in the blood were examined. Abnormalities of thyroid gland function were not detected. Loosening of the implants was not observed. Excellent bone ingrowth and ongrowth were found around iodine-supported megaprostheses. The iodine-supported titanium megaprostheses are highly effective and show promise for the prevention and treatment of infections in large bone defects. No cytotoxicity or adverse effects were detected with this treatment. PMID:24913616

Shirai, Toshiharu; Tsuchiya, Hiroyuki; Nishida, Hideji; Yamamoto, Norio; Watanabe, Koji; Nakase, Junsuke; Terauchi, Ryu; Arai, Yuji; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2014-10-01

358

Laser Welding in Space  

NASA Technical Reports Server (NTRS)

Solidification type welding process experiments in conditions of microgravity were performed. The role of convection in such phenomena was examined and convective effects in the small volumes obtained in the laser weld zone were observed. Heat transfer within the weld was affected by acceleration level as indicated by the resulting microstructure changes in low gravity. All experiments were performed such that both high and low gravity welds occurred along the same weld beam, allowing the effects of gravity alone to be examined. Results indicate that laser welding in a space environment is feasible and can be safely performed IVA or EVA. Development of the hardware to perform the experiment in a Hitchhiker-g platform is recomended as the next step. This experiment provides NASA with a capable technology for welding needs in space. The resources required to perform this experiment aboard a Shuttle Hitchhiker-pallet are assessed. Over the four year period 1991 to 1994, it is recommended that the task will require 13.6 manyears and $914,900. In addition to demonstrating the technology and ferreting out the problems encountered, it is suggested that NASA will also have a useful laser materials processing facility for working with both the scientific and the engineering aspects of materials processing in space. Several concepts are also included for long-term optimization of available solar power through solar pumping solid state lasers directly for welding power.

Workman, Gary L.; Kaukler, William F.

1989-01-01

359

Frequency locking to the center of a 532 nm iodine absorption line by using stimulated Brillouin  

E-print Network

and Brillouin scattering experiments use iodine filters to suppress parasitic scattered light from windows- ing from particulate scattering. The laser frequency must be held within 100 MHz of line center scattering from a single-mode fiber E. W. Eloranta and I. A. Razenkov University of Wisconsin--Madison, 1225

Eloranta, Edwin W.

360

Proceedings of the XI International Symposium on Gas Flow and Chemical Lasers and High Power Laser Conference, Edinburgh, UK 25-30 August 1996, SPIE Vol. 3092, ed. H.J. Baker, pp. 758-763 (1997).  

E-print Network

for the atomic iodine laser transition of interest. A block diagram of a typical COIL system is illustrated-5776 ABSTRACT A chemical oxygen-iodine laser (COIL) was used for cutting aluminum and carbon steel. Cut depths are compared with existing COIL and CO2 laser cutting data. COIL cuts carbon steel and stainless steel

Carroll, David L.

361

Iodine status in pregnancy and household salt iodine content in rural Bangladesh.  

PubMed

Adequate maternal iodine intake is essential during pregnancy for the development of the foetus. To assess the extent of iodine insufficiency and its association with household iodized salt in rural Bangladesh, we measured urinary iodine and household salt iodine content among pregnant women in early (?16 weeks, n = 1376) and late (?32 weeks, n = 1114) pregnancy. Salt (?20 g) and a spot urine sample (?10 mL) were collected from women participating in a randomized, placebo-controlled trial of vitamin A or beta-carotene supplementation in rural northwestern Bangladesh during home visits in early and late pregnancy. Salt iodine was analyzed by iodometric titration, and urinary iodine by the Ohashi method. Almost all salt samples had some detectable iodine, but over 75% contained <15 ppm. Median (interquartile range) urinary iodine concentrations were 66 (34-133) and 55 (28-110) µg L?¹ in early and late pregnancy, respectively; urinary iodine <150 µg L?¹ was found in ?80% of women at both times in pregnancy. Although the risk of iodine insufficiency declined with increasing iodine content of household salt (P for trend <0.05), median urinary iodine did not reach 150 µg L?¹ until iodine in household salt was at least 32 ppm and 51 ppm during early and late pregnancy, respectively. Despite a national policy on universal salt iodization, salt iodine content remains insufficient to maintain adequate maternal iodine status throughout pregnancy in rural northern Bangladesh. Alternative measures like direct iodine supplementation during pregnancy could be considered to assure adequate iodine status during this high-risk period of life. PMID:20977661

Shamim, Abu Ahmed; Christian, Parul; Schulze, Kerry J; Ali, Hasmot; Kabir, Alamgir; Rashid, Mahbubur; Labrique, Alain; Salamatullah, Qauzi; West, Keith P

2012-04-01

362

Effect of iodine disinfectant source and water quality parameters on soluble iodine speciation  

NASA Technical Reports Server (NTRS)

Investigations of iodine species distribution of various aqueous solutions of iodine disinfectants and water from equilibrated suspensions of triodide and pentaiodide resins were done at the University of Colorado for the Center for Space Environmental Health during 1992 and 1993. Direct measurements of three individual iodine species: I(-), I2 and I3(-), were made. In addition three measures of total titratable iodine species were used. It has been found that I2 and I3(-) solutions produce a significant fraction of the non-disinfecting species iodine I(-), ranging from 50 to 80% of added iodine, respectively, at pH values of approximately 5. Correspondingly, I2 solutions produce more than twice the concentration of disinfecting iodine species per mass iodine dose than I3(-) solutions. Both I(-) and I2 species were found in aqeuous extracts of pentaiodide resin, although no soluble species were detected with triiodide resin.

Silverstein, Joann; Hurst, Charles; Barkley, Robert; Dunham, Andrew

1993-01-01

363

Pressure recovery devices for supersonic COIL lasers  

Microsoft Academic Search

The basic challenge in the design of a pressure recovery system for a supersonic gas laser arises from the fact that the cavity pressure is quite low: 50 - 70 torr for a CO2 gasdynamic laser (GDL) and as low as 4 torr for a chemical oxygen-iodine laser (COIL) system. The purpose of the pressure recovery system is to increase

Robert F. Walter; Robert A. O'Leary

1993-01-01

364

Disposal of radioactive iodine in space  

NASA Technical Reports Server (NTRS)

The possibility of space disposal of iodine waste from nuclear power reactors is investigated. The space transportation system utilized relies upon the space shuttle, a liquid hydrogen/liquid oxygen orbit transfer vehicle, and a solid propellant final stage. The iodine is assumed to be in the form of either an iodide or an iodate, and calculations assume that the final destination is either solar orbit or solar system escape. It is concluded that space disposal of iodine is feasible.

Burns, R. E.; Defield, J. G.

1978-01-01

365

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy  

NASA Astrophysics Data System (ADS)

The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L 3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine forming covalent bonds with organic molecules. Simulation of XANES spectra by linear combination of reference spectra suggested the predominance of iodine forming covalent bonds to aromatic rings (aromatic-bound iodine). Comparison of extended X-ray absorption fine structure (EXAFS) spectra of reference and samples further showed that iodine was surrounded by carbon shells at distances comparables to those for references containing aromatic-bound iodine. Quantitative analysis of EXAFS spectra indicated that iodine was bound to about one carbon at a distance d (I-C) of 2.01(4)-2.04(9) Å, which was comparable to the distances observed for aromatic-bound iodine in references (1.99(1)-2.07(6) Å), and significantly shorter than that observed for aliphatic-bound iodine (2.15(2)-2.16(2) Å). These results are in agreement with previous conclusions from X-ray photoelectron spectroscopy and from electrospray ionization mass spectrometry. These results collectively suggest that the aromatic-bound iodine is stable in the various aquifers of this study.

Schlegel, Michel L.; Reiller, Pascal; Mercier-Bion, Florence; Barré, Nicole; Moulin, Valérie

2006-11-01

366

Original article Iodine nutrition in ewes : effects of low to high iodine  

E-print Network

no effect on the dry matter intake, the size or the weight of the litter and the length of pregnancy. PlasmaOriginal article Iodine nutrition in ewes : effects of low to high iodine intake on iodine content, for pregnancy and lactation. In a second experiment, 3 groups of 10 nullipa- rous ewes received diets which

Boyer, Edmond

367

Ultrasensitive diagnostics for small signal gain in COIL and AGIL lasers  

Microsoft Academic Search

In this paper we describe a novel, ultra-sensitive diode laser based diagnostic for small signal gain in atomic iodine based laser systems. We describe the overall diagnostic design and present initial data on the sensitivity of the device.

Steven J. Davis; Phillip A. Mulhall; Jan Polex; William J. Kessler

2003-01-01

368

Ultrasensitive diagnostics for small signal gain in COIL and AGIL lasers  

NASA Astrophysics Data System (ADS)

In this paper we describe a novel, ultra-sensitive diode laser based diagnostic for small signal gain in atomic iodine based laser systems. We describe the overall diagnostic design and present initial data on the sensitivity of the device.

Davis, Steven J.; Mulhall, Phillip A.; Polex, Jan; Kessler, William J.

2003-06-01

369

Spectral properties of molecular iodine in absorption cells filled to specified saturation pressure.  

PubMed

We present the results of measurement and evaluation of spectral properties of iodine absorption cells filled at certain saturation pressure. A set of cells made of borosilicate glass instead of common fused silica was tested for their spectral properties in greater detail with special care for the long-term development of the absorption media purity. The results were compared with standard fused silica cells and the high quality of iodine was verified. A measurement method based on an approach relying on measurement of linewidth of the hyperfine transitions is proposed as a novel technique for iodine cell absorption media purity evaluation. A potential application in laser metrology of length is also discussed. PMID:25402909

Hrabina, Jan; Šarbort, Martin; Acef, Ouali; Burck, Frédéric Du; Chiodo, Nicola; Holá, Miroslava; ?íp, Ond?ej; Lazar, Josef

2014-11-01

370

Laser welding with high power lasers combining system  

Microsoft Academic Search

We have developed the high power laser beam combining system with the 10kW class chemical oxygen-iodine laser (COIL) of wavelength 1.315µm and the 6kW class Nd:YAG laser of wavelength 1.064µm. The characteristic of the beam propagation, the combining beam quality and the optics were evaluated. The combining beam providing power was up to over 16kW. The combining beam was used

Mikio Muro; Tokuhiro Nakabayashi; Yoshiaki Hayakawa; Fumio Wani; Kozo Yasuda; Fumisato Mifune; Kouichi Yoshida

2000-01-01

371

5, 2564, 2008 Iodine speciation and  

E-print Network

BGD 5, 25­64, 2008 Iodine speciation and cycling in lakes B. S. Gilfedder et al. Title Page speciation and cycling in limnic systems: observations from a humic rich headwater lake (Mummelsee) B. S­64, 2008 Iodine speciation and cycling in lakes B. S. Gilfedder et al. Title Page Abstract Introduction

Paris-Sud XI, Université de

372

An Iodine Fluorescence Quenching Clock Reaction  

ERIC Educational Resources Information Center

Clock reactions based upon competing oxidation and reduction reactions of iodine and starch as the most popular type of chemistry example is presented to illustrate the redox phenomena, reaction kinetics, and principles of chemical titration. The examination of the photophysical principles underlying the iodine fluorescence quenching clock…

Weinberg, Richard B.; Muyskens, Mark

2007-01-01

373

Immobilization of iodine in soil-water systems and its relation to iodine species  

NASA Astrophysics Data System (ADS)

Iodine tends to accumulate in thyroid, and radioactive 131I and 129I are threatening to human health both short-term and long-term, respectively. It is thus important to understand iodine behavior in surface environments. Possible iodine species are I-, IO3-, I2, and organo-iodine species. X-ray absorption near-edge structure (XANES) and high performance liquid chromatography (HPLC) connected to ICP-MS were used to determine iodine species in soil and pore water, respectively. Soil and pore water samples were collected at depths of 0 to 12 cm near a tube well in Yoro, Chiba, Japan, where surface soil is flooded with brine containing iodine of 5.8 mg/L. Soil samples were also collected at depths of 0 to 90 cm in Yakushima Island, Kagoshima, Japan. The soil samples were frozen, and iodine K-edge XANES were measured at BL01B1, SPring-8 (Hyogo, Japan). Soil samples were buried into resin and prepared as thin sections, and mapping of iodine in soil grain was obtained using ?-XRF analysis at BL37XU, SPring-8. HPLC-ICP-MS, equipped with anion exchange or size exclusion column, was used to determine iodine species in pore water. Yoro: The depth profile of iodine concentration in soil correlates quite well with that of organic carbon content. XANES spectra are almost identical to that of humic substances at any depth (Fig. 1). Iodine mapping shows that iodine exists in organic matter more than clay minerals and iron rich mineral. Iodine in pore water exists as I- and organic iodine bound to dissolved humic substances at 0-6 cm, and mainly as I- at 9-12 cm, respectively. Thus, iodine tends to be bound to organic materials in soil as organic iodine, where as iodine in pore water exists mainly as I-. Yakushima: Iodine concentration is higher in volcanic ash soil layer (25-55 cm) than surface organic rich soil layer (0-25 cm). XANES spectrum of volcanic ash soil was different from those of reference materials (Fig. 1). Volcanic ash soil in Yakushima contains imogolite and allophane. Iodide has greater affinity to imogolite than ferrihydrite[1]. It is suggested that clay minerals, such as imogolite, are also important to retain iodine especially in volcanic ash soils. [1] Yu et al. 1996, Geochim. Cosmochim. Acta 60, 4945-4956. Fig. 1 XANES spectra of standard materials and soil samples.

Shimamoto, Y.; Takahashi, Y.

2009-12-01

374

Risk of Suboptimal Iodine Intake in Pregnant Norwegian Women  

PubMed Central

Pregnant women and infants are exceptionally vulnerable to iodine deficiency. The aims of the present study were to estimate iodine intake, to investigate sources of iodine, to identify predictors of low or suboptimal iodine intake (defined as intakes below 100 ?g/day and 150 ?g/day) in a large population of pregnant Norwegian women and to evaluate iodine status in a sub-population. Iodine intake was calculated based on a validated Food Frequency Questionnaire in the Norwegian Mother and Child Cohort. The median iodine intake was 141 ?g/day from food and 166 ?g/day from food and supplements. Use of iodine-containing supplements was reported by 31.6%. The main source of iodine from food was dairy products, contributing 67% and 43% in non-supplement and iodine-supplement users, respectively. Of 61,904 women, 16.1% had iodine intake below 100 ?g/day, 42.0% had iodine intake below 150 ?g/day and only 21.7% reached the WHO/UNICEF/ICCIDD recommendation of 250 ?g/day. Dietary behaviors associated with increased risk of low and suboptimal iodine intake were: no use of iodine-containing supplements and low intake of milk/yogurt, seafood and eggs. The median urinary iodine concentration measured in 119 participants (69 ?g/L) confirmed insufficient iodine intake. Public health strategies are needed to improve and secure the iodine status of pregnant women in Norway. PMID:23389302

Brantsæter, Anne Lise; Abel, Marianne Hope; Haugen, Margaretha; Meltzer, Helle Margrete

2013-01-01

375

Fluorescence analysis of iodinated acetophenone derivatives.  

PubMed

In the present paper the synthesis and optical characterization of iodinated acetophenone, 4-hydroxy-3-iodoacetophenone and 4-hydroxy-3,5-diiodoacetophenone obtained from 4-hydroxyacetophenone, were carried out. The optical features of iodinated molecules were determined by performing the UV-Vis absorption, fluorescence and thermal lens spectroscopies. The results showed that the optical properties of the 4-hydroxyacetophenone is altered when the iodine atom is inserted, as substituent, in the aromatic ring. Although it was determined that the optical feature was changed when one iodine atom was inserted in the aromatic ring (4-hydroxy-3-iodoacetophenone), the results revealed that emission behavior was strongly altered when two iodine atoms (4-hydroxy-3,5-diiodoacetophenone) were acting as substituents: the fluorescence quantum efficiency increases approximately 60%. PMID:25554953

Crivelaro, F; Oliveira, M R S; Lima, S M; Andrade, L H C; Casagrande, G A; Raminelli, C; Caires, A R L

2015-03-15

376

AIAA Plasmadynamics and Lasers Conference 6-9 June 2005, Toronto, Ontario Canada  

E-print Network

. Introduction HE classic chemical oxygen-iodine laser (COIL) system1 operates on the I(2 P1/2) I(2 P336 th AIAA Plasmadynamics and Lasers Conference 6-9 June 2005, Toronto, Ontario Canada AIAA 2005 In an electric discharge Oxygen-Iodine laser (ElectricOIL), laser action at 1315 nm on the I(2 P1/2) I(2 P3

Carroll, David L.

377

Laser Fine-Adjustment Thruster For Space Vehicles  

SciTech Connect

To the present time, a few laser propulsion engine devices have been developed by using dominant mechanisms of laser propulsion. Generally these mechanisms are laser ablation, laser breakdown of gases, and laser detonation waves that are induced due to extraction of the internal energy of polymer propellants. In the paper, we consider the Aero-Space Laser Propulsion Engine (ASLPE) developed earlier, in which all of these mechanisms are realized via interaction of laser radiation with polymers both in continuous wave (CW) and in repetitively pulsed modes of laser operation. The ASLPE is considered to be exploited as a unit of a laser propulsion device being arranged onboard space vehicles moving around the Earth or in interplanetary missions and intended to correct the vehicles orbits. To produce a thrust, a power of the solar pumped lasers designed to the present time is considered in the paper. The problem of increasing the efficiency of the laser propulsion device is analyzed as applied to space missions of vehicles by optimizing the laser propulsion propellant composition.

Rezunkov, Yu. A.; Egorov, M. S.; Repina, E. V.; Safronov, A. L. [Research Institute for Complex Testing of Optic-Electronic Devices, Sosnovy Bor, Leningrad region, Russian Federation, 188540 (Russian Federation); Rebrov, S. G. [Keldyish Research Center, Moscow (Russian Federation)

2010-05-06

378

Recent results in the development of a chemical way of atomic iodine generation for a COIL  

NASA Astrophysics Data System (ADS)

The results of theoretical and experimental investigation of gas phase chemical generation of atomic iodine, I(2P3/2), for stimulated emission in chemical oxygen-iodine laser (COIL) are presented. The method of I atoms generation employs a principal reaction X+HI implies I(2P3/2)+HX, where X equals F or Cl. A computational modeling was based on the 1D flow development exploring the chemical processes within the reaction systems, and was aimed at the theoretical understanding of the two complex reaction systems and finding out which is better applicable for conditions in COIL. The results of modeling were further used for a design of the device and conditions during the experimental investigation, and for an interpretation of the experimental results. The experimental work has been done, for the present, on the atomic iodine generation via Cl atoms. A high yield of atomic iodine of 70% to 100% (related to the initial HI flow rate) was attained in a flow of nitrogen. Gain was observed in preliminary experiments on the chemical generation of atomic iodine in a flow of singlet oxygen.

Kodymova, Jarmila; Spalek, Otomar; Jirasek, Vit; Censky, Miroslav; Hager, Gordon D.

2002-09-01

379

Urinary Iodine Clearance following Iodinated Contrast Administration: A Comparison of Euthyroid and Postthyroidectomy Subjects  

PubMed Central

Purpose. To compare iodine clearance following iodinated contrast administration in thyroidectomised thyroid cancer patients and euthyroid individuals. Methods. A convenience population (6 thyroidectomised thyroid cancer patients and 7 euthyroid controls) was drawn from patients referred for iodinated contrast-enhanced computed tomography (CT) studies. Subjects had sequential urine samples collected up to 6 months (50 samples from the thyroidectomised and 63 samples from the euthyroid groups). t-tests and generalised estimating equations (GEE) were used to test for group differences in urinary iodine creatinine ratios. Results. Groups had similar urinary iodine creatinine ratios at baseline, with a large increase 2 weeks following iodinated contrast (P = 0.005). Both groups had a return of urinary iodine creatinine ratios to baseline by 4 weeks, with no significant group differences overall or at any time point. Conclusions. Thyroidectomised patients did not have a significantly different urinary iodine clearance than euthyroid individuals following administration of iodinated contrast. Both had a return of urinary iodine creatinine ratios to baseline within 4 weeks. PMID:25478285

Ho, Janice D.; Tsang, James F.; Scoggan, Kylie A.; Leslie, William D.

2014-01-01

380

Current Iodine Nutrition Status and Awareness of Iodine Deficiency in Tuguegarao, Philippines  

PubMed Central

The Philippines is one of the countries where adequate iodine status has been achieved. However, iodine deficiency still remains an important public health problem in this country. In this study, we evaluated iodine nutrition status and investigated an awareness status of iodine deficiency targeting high school students of Tuguegarao, Philippines. A total of 260 students provided samples for urinary iodine analysis, among which 146 students completed thyroid volume measurement by ultrasonography and answering the questionnaires. The median urinary iodine level was 355.3?µg/L and only 3.8% of the students were in the range of iodine deficiency status according to the ICCIDD criteria. Although 62.3% of students answered that they can list problems resulting from iodine deficiency, a majority of students (70.5%) were unable to identify problems other than goiter. They did not appreciate that adequate iodine levels are important during pregnancy and for development of children. 33.6% of students answered that they did not use iodized salt and the biggest reason was that they did not find it necessary. Based on these results, we suggest that a future strategy should be focused on vulnerable groups to completely eliminate iodine deficiency, including women at their reproductive ages and during pregnancy. PMID:25374598

Kim, Bu Kyung; Seok, Kwang-Hyuk; Lee, Andrew S.; Oak, Chul Ho; Kim, Ghi Chan; Jeong, Chae-Kyeong; Choi, Sung In; Afidchao, Pablo M.; Choi, Young Sik

2014-01-01

381

History of U.S. Iodine Fortification and Supplementation  

PubMed Central

Iodine is a micronutrient required for thyroid hormone production. This review highlights the history of the discovery of iodine and its uses, discusses the sources of iodine nutrition, and summarizes the current recommendations for iodine intake with a focus on women of childbearing age. PMID:23201844

Leung, Angela M.; Braverman, Lewis E.; Pearce, Elizabeth N.

2012-01-01

382

Laser research at the Institute of Physics AS CR  

NASA Astrophysics Data System (ADS)

Laser research at the Institute of Physics of the Academy of Sciences of Czech Republic covers both the development of advanced pulsed high-power laser systems, the iodine and x-ray in particular, and their applications in science and technology. The COIL laboratory with a small chemical oxygen-iodine laser facility participates in the worldwide effort to develop a competitive quasi-steady laser device for industrial and military applications. In the new laboratory SOFIA a unique hybrid laser system consisting of a commercial crystal oscillator and iodine power amplifiers (SOFIA = Solid State Oscillator Followed by Iodine Amplifiers) has been developed. It is used as a pump of parametric amplifiers in a pilot OPCPA experiment. Our largest laboratory, the PALS Research Centre operated jointly with the Institute of Plasma Physics AS CR, is open to external users, offering them the beam time of the TW/ns iodine laser system PALS (Prague Asterix Laser System). Several tens of experimental projects have been performed at PALS since September 2000, aimed e.g. at various applications of plasma XUV sources, QSS plasma XUV lasers, laser ion sources, and laser-induced shock waves. An overview of the research programmes of all the three laboratories is given in the paper.

Jungwirth, Karel

2005-03-01

383

Computation of iodine species concentrations in water  

NASA Technical Reports Server (NTRS)

During an evaluation of the use of iodine as a water disinfectant and the development of methods for measuring various iodine species in water onboard Space Freedom, it became necessary to compute the concentration of the various species based on equilibrium principles alone. Of particular concern was the case when various amounts of iodine, iodide, strong acid, and strong base are added to water. Such solutions can be used to evaluate the performance of various monitoring methods being considered. The authors of this paper present an overview of aqueous iodine chemistry, a set of nonlinear equations which can be used to model the above case, and a computer program for solving this system of equations using the Newton-Raphson method. The program was validated by comparing results over a range of concentrations and pH values with those previously presented by Gottardi for a given pH. Use of this program indicated that there are multiple roots to many cases and selecting an appropriate initial guess is important. Comparison of program results with laboratory results for the case when only iodine is added to water indicates the program gives high pH values for the iodine concentrations normally used for water disinfection. Extending the model to include the effects of iodate formation results in the computer pH values being closer to those observed, but the model with iodate does not agree well for the case in which base is added in addition to iodine to raise the pH. Potential explanations include failure to obtain equilibrium conditions in the lab, inaccuracies in published values for the equilibrium constants, and inadequate model of iodine chemistry and/or the lack of adequate analytical methods for measuring the various iodine species in water.

Schultz, John R.; Mudgett, Paul D.; Flanagan, David T.; Sauer, Richard L.

1994-01-01

384

Effect of chronic douching with polyvinylpyrrolidone-iodine on iodine absorption and thyroid function  

SciTech Connect

Daily vaginal douching with polyvinylpyrrolidone-iodine in 12 euthyroid volunteers for 14 days resulted in a significant increase in serum total iodine concentration and urine iodine excretion. The increase in serum total iodine was associated with a marked decrease in 24-hour /sup 123/I uptake by the thyroid and a small but significant increase in serum thyrotropin (TSH) concentration. However, values for serum TSH never rose above the normal range. No significant changes in serum thyroxine (T4), free T4 index (FTI), or triiodothyronine concentrations were observed, although serum T4 and FTI did decrease slightly during treatment. The findings suggest that iodine is absorbed across the vaginal mucosa and that the subsequent increase in serum total iodine does induce subtle increases in serum TSH concentration. There was no evidence, however, of overt hypothyroidism in these euthyroid women.

Safran, M.; Braverman, L.E.

1982-07-01

385

Evaluation of Accessibility of Iodinated Salt and Nutritional Iodine Status during Pregnancy  

PubMed Central

Background: To assess accessibility of iodinated salt and urinary iodine concentrations (UIC) during pregnancy. This cross-sectional study was carried out between October and December, 2009 in Urmia County, West Azerbaijan (WA), Iran. Methods: Data on demographic characteristics and iodinated salt accessibility were gathered through a questionnaire at 1st trimester. Household salt samples and urine samples (1st –and 3rd trimesters) were analyzed for iodine content. Pregnant women (n=490) at 1st trimester were interviewed. Of these, 490 subjects (12 prenatal care centers) were enrolled. Results: All participants declared that they were exclusive users of iodinated salt. Segregation of the household salt samples according to iodine content (0, 8, 15 and 30 ppm) revealed that the respective distributions were 3.3%, 1.4%, 23.7% and 71.6%. Median UIC levels at 1st and 3rd trimesters were 73.5 ?g/L and 114?g/L respectively. Accordingly, 86% and 70% of participants exhibited UIC < 150 ?g/L. Conclusion: Median UIC during pregnancy in WA is markedly lower than those previously reported for regions with adequate iodine status in the country. Thus, extra iodine is needed to maintain adequate iodine store during gestation. In addition, this preliminary study reveals that a significant proportion (28%) of the household salt samples had low iodine content (? 15 ppm) although a level (>20 and <40 ppm) is mandatory in Iran. Further studies are deemed necessary to elucidate the cause(s) for manifestation iodine deficiency among pregnant women despite 20 years after iodine fortification strategy. PMID:23113225

Rostami, R; Beiranvand, A; Khakhali, HR; Salary, S; Aghasi, MR; Nourooz-Zadeh, J

2012-01-01

386

Method for immobilizing radioactive iodine  

DOEpatents

Radioactive iodine, present as alkali metal iodides or iodates in an aqueous solution, is incorporated into an inert solid material for long-term storage by adding to the solution a stoichiometric amount with respect to the formation of a sodalite (3M.sub.2 O.3Al.sub.2 O.sub.3. 6SiO.sub.2.2MX, where M=alkali metal; X=I.sup.- or IO.sub.3.sup.-) of an alkali metal, alumina and silica, stirring the solution to form a homogeneous mixture, drying the mixture to form a powder, compacting and sintering the compacted powder at 1073 to 1373 K (800.degree. to 1100.degree. C.) for a time sufficient to form sodalite.

Babad, Harry (Richland, WA); Strachan, Denis M. (Richland, WA)

1980-01-01

387

Tositumomab and Iodine I 131 Tositumomab  

Cancer.gov

This page contains brief information about tositumomab and iodine I 131 tositumomab and a collection of links to more information about the use of this drug, research results, and ongoing clinical trials.

388

Achievement of ultrahigh solar concentration with potential for efficient laser pumping  

NASA Astrophysics Data System (ADS)

The irradiance produced by a two-stage solar concentrator designed to approach the thermodynamic limit has been measured. In the present experimental method, sunlight is collected by a 40.6-cm diameter parabolic primary which forms a 0.98-cm diameter image. This image is then reconcentrated. The highest irradiance value achieved was 4.4 + or - 0.2 kW/sq cm, and the efficiency with which 55 W of sunlight is concentrated to a small spot suggests that the system has application to the solar pumping of solid state lasers.

Gleckman, Philip

1988-11-01

389

Iodine-induced thyroid blockade: role of selenium and iodine in the thyroid and pituitary glands.  

PubMed

The purpose of this study was to determine the content of iodine and selenium in the thyroid and pituitary glands of rats under iodine-induced blockade of the thyroid gland. Electron probe microanalysis, wavelength-dispersive spectrometry, and point analysis were used in this investigation. We also determined the expression of sodium iodide symporter and caspase 32 in the thyroid and pituitary glands and the expression of thyroid-stimulating hormone in the pituitary. The samples for iodine analysis must be thoroughly dehydrated, and for this purpose, we developed a method that produced samples of constant mass with minimal loss of substrate (human thyroid gland was used for the investigation). Normal levels of iodine and selenium were found in the thyroid, pituitary, ovaries, testes hypothalamus, and pancreas of healthy rats. The levels of iodine and selenium in I- or Se-positive points and the percentage of positive points in most of these organs were similar to those of controls (basal level), except for the level of iodine in the thyroid gland and testes. Blockade of the thyroid gland changed the iodine level in iodine-positive points of the thyroid and the pituitary glands. On the sixth day of blockage, the iodine level in iodine-positive points of the thyroid gradually decreased to the basal level followed by an abrupt increase on the seventh day, implying a rebound effect. The opposite was found in the pituitary, in which the level of iodine in iodine-positive points increased during the first 6 days and then abruptly decreased on the seventh day. Expression of the thyroid-stimulating hormone in the pituitary decreased during the first 5 days but sharply increased on the sixth day, with a minimum level of iodine in the thyroid and maximum in the pituitary, before normalization of the iodine level in both glands preceding the rebound effect. The expression of sodium iodide symporter increased during the first 4 days of blockage and then decreased in both glands. The fluctuations of the thyroid-stimulating hormone in the pituitary gland reflected the changes of iodine in the thyroid gland more precisely than the changes of sodium iodide symporter. The selenium level in the selenium-positive points changed only in the pituitary, dropping to zero on the second and fifth day of the blockade. Simultaneously, the maximum induction of caspase 32 was observed in the pituitary gland. We believe that these results may help to clarify a role of the pituitary gland in the thyroid blockade. PMID:23771684

Basalaeva, Nadezdha L

2013-08-01

390

Study of iodine diffusion in silicon carbide  

NASA Astrophysics Data System (ADS)

Diffusion of iodine in 6H-SiC and polycrystalline CVD-SiC was investigated using Rutherford backscattering spectroscopy and electron microscopy. A fluence of 1 × 10 16 cm -2 of 127I + was implanted with an energy of 360 keV at room temperature, producing an amorphous surface layer of approximately 220 nm thickness. The implantation profile reached an atomic density of approximately 1.3% at the projected range of about 95 nm. Broadening of the implantation profile and iodine loss through the front surface during isochronal and isothermal vacuum annealing was determined. At a temperature of 1100 °C no iodine loss was observed after 120 h and a diffusion coefficient of less than 10 -21 m 2 s -1 was extracted from the analysis of profile widths. Relatively strong broadening occurred after 60 h annealing at 1200 °C with the iodine profile extending beyond 300 nm into the bulk, accompanied by a surprisingly modest iodine loss through the surface. Electron microscopic studies reveal a drastic restructuring of the surface region at this temperature, indicating possible chemical reactions between iodine and silicon carbide.

Friedland, E.; van der Berg, N. G.; Malherbe, J. B.; Kuhudzai, R. J.; Botha, A. J.; Wendler, E.; Wesch, W.

2010-10-01

391

Pulse discharge production of iodine atoms for COIL  

NASA Astrophysics Data System (ADS)

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.

Napartovich, Anatoly; Kochetov, Igor; Vagin, Nikolay; Yuryshev, Nikolay

2006-10-01

392

High-power COIL and YAG laser welding  

Microsoft Academic Search

We have constructed a laser welding system, which enabled high-power laser welding by combining three laser beams of 1 mm wavelength. Its wavelength enables optical silica fibers transmission and the flexible system. The heart of this system consists of a 4 kW and a 6 kW Nd:YAG lasers and a 10 kW Chemical Oxygen-Iodine Laser (COIL). The average power of

Fumio Wani; Tokuhiro Nakabayashi; Akiyoshi Hayakawa; Sachio Suzuki; Kozu Yasuda

2002-01-01

393

High-power COIL and Nd:YAG laser welding  

Microsoft Academic Search

We have constructed a laser welding system, which enabled high-power laser welding by combining three laser beams of 1 µm wavelength. Its wavelength enables optical silica fibers transmission and the flexible system. The heart of this system consists of a 4 kW and a 6 kW Nd:YAG lasers and a 10 kW class Chemical Oxygen-Iodine Laser (COIL) beams of 6

Fumio Wani; T. Nakabayashi; A. Hayakawa; S. Suzuki; K. Yasuda

2003-01-01

394

Noise-immune laser receiver - transmitters with the quantum sensitivity limit  

SciTech Connect

We consider the operation principles of noise-immune near-IR receiver - transmitters with the quantum sensitivity limit, in which active quantum filters based on iodine photodissociation quantum amplifiers and iodine lasers are used. The possible applications of these devices in laser location, laser space communication, for the search for signals from extraterrestrial civilisations and sending signals to extraterrestrial civilisations are discussed. (invited paper)

Kutaev, Yu F; Mankevich, S K ['Astrofizika' Research and Production Association (Russian Federation); Nosach, O Yu; Orlov, E P [P N Lebedev Physical Institute, Russian Academy of Sciences, Moscow (Russian Federation)

2009-11-30

395

The uptake of elemental iodine vapour by bean leaves  

NASA Astrophysics Data System (ADS)

Deposition of iodine vapour to leaves of phaseolus vulgaris was measured over a range of conditions of humidity, temperature and illumination. Transpiration measurements were used to deduce stomatal opening. The results showed that stomatal resistance controlled iodine absorption at relative humidities below 40 per cent, but that the rate of absorption of iodine increased by an order of magnitude when the relative humidity was raised to 80 per cent, presumably due to cuticular absorption. After exposure to iodine at high humidity, a substantial fraction of the iodine could be washed from the leaves. In Britain, cuticular uptake would probably dominate stomatal uptake of iodine on most occasions.

Garland, J. A.; Cox, L. C.

396

Effects of Increased Iodine Intake on Thyroid Disorders  

PubMed Central

Iodine is a micronutrient essential for the production of thyroid hormones. Iodine deficiency is the most common cause of preventable mental impairment worldwide. Universal salt iodization (USI) has been introduced in many countries as a cost-effective and sustainable way to eliminate iodine deficiency disorders for more than 25 years. Currently, the relationship between USI and iodine excess has attracted more attention. Iodine excess can lead to hypothyroidism and autoimmune thyroiditis, especially for susceptible populations with recurring thyroid disease, the elderly, fetuses, and neonates. Nationwide USI was introduced in China in 1996. This review focused on the effects of iodine excess worldwide and particularly in China. PMID:25309781

Sun, Xin; Shan, Zhongyan

2014-01-01

397

Iodine-129 Dose in LLW Disposal Facility Performance Assessments  

SciTech Connect

Iodine-129 has the lowest Performance Assessment derived inventory limit in SRS disposal facilities. Because iodine is concentrated in the body to one organ, the thyroid, it has been thought that dilution with stable iodine would reduce the dose effects of 129I.Examination of the dose model used to establish the Dose conversion factor for 129I shows that, at the levels considered in performance assessments of low-level waste disposal facilities, the calculated 129I dose already accounts for ingestion of stable iodine. At higher than normal iodine ingestion rates, the uptake of iodine by the thyroid itself decrease, which effectively cancels out the isotopic dilution effect.

Wilhite, E.L.

1999-10-15

398

Mixed-layered bismuth-oxygen-iodine materials for capture and waste disposal of radioactive iodine  

DOEpatents

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

Krumhansl, James L; Nenoff, Tina M

2013-02-26

399

Industrial COIL systems--part 1: laser beam delivery by fiber  

Microsoft Academic Search

First results of experimental and theoretical investigations related to an industrial application of oxygen-iodine laser (COIL) are reported. A developed calculative model determines a transmission factor of a laser emission at a set wavelength depending on the waveguide parameters, focusing system characteristics, and laser emission intensity angular distribution. Carried out investigations concerned with delivery of a laser emission power up

Sergey P. Ilyin; Vladimir V. Buzoverya; Anatoly A. Adamenkov; Victor V. Bakshin; Valentin I. Efremov; David G. Kochiev; Yuriy V. Kolobyanin; Vladimir B. Moiseev; Boris A. Vyskubenko

2005-01-01

400

Teratology Public Affairs Committee Position Paper: Iodine Deficiency in Pregnancy  

PubMed Central

Iodine deficiency is an important nutritional deficiency, with more than 2 billion people worldwide estimated to be at risk. The developing fetus and young children are particularly at risk. During pregnancy and lactation, iodine requirements increase, whether in iodine-poor or iodine-sufficient countries, making the mother and the developing fetus vulnerable. The American Thyroid Association (ATA) recommends 250 micrograms per day of iodine intake for pregnant and lactating women. The thyroid gland is able to adapt to the changes associated with pregnancy as long as sufficient iodine is present. Dietary intake is the sole source of iodine, which is essential to the synthesis of thyroid hormones. Iodine is found in multiple dietary sources including iodized salt, dairy products, seaweed, and fish. Prenatal vitamins containing iodine are a good source of iodine, but iodine content in multivitamin supplements is highly variable. Congenital hypothyroidism is associated with cretinism. Clinical hypothyroidism has been associated with increased risk of poor perinatal outcome including prematurity, low birth weight, miscarriage, preeclampsia, fetal death, and impaired fetal neurocognitive development. Subclinical hypothyroidism is also associated with poor pregnancy outcomes and potential fetal neurocognitive deficits, but the data are more variable than those for clinical hypothyroidism. We concur with the ATA recommendation that all pregnant and lactating women should ingest (through diet and supplements) 250 micrograms of iodine daily. To achieve this goal, we recommend that all pregnant and lactating women take daily iodine supplementation of 150 micrograms. PMID:22903940

Obican, Sarah G.; Jahnke, Gloria D.; Soldin, Offie P.; Scialli, Anthony R.

2013-01-01

401

Iodine chemical forms in LWR severe accidents  

SciTech Connect

Calculated data from seven severe accident sequences in light-water reactor plants were used to assess the chemical forms of iodine in containment. In most of the calculations for the seven sequences, iodine entering containment from the reactor coolant system was almost entirely in the form of CsI with very small contributions of I or HI. The largest fraction of iodine in forms other than CsI was a total of 3.2% as I plus HI. Within the containment, the CsI will deposit onto walls and other surfaces, as well as in water pools, largely in the form of iodide (I{sup {minus}}). The radiation induced conversion of I{sup {minus}} in water pools into I{sub 2} is strongly dependent on pH. In systems where the pH was controlled above 7, little additional elemental iodine would be produced in the containment atmosphere. When the pH falls below 7, it may be assumed that it is not being controlled, and large fractions of iodine as I{sub 2} within the containment atmosphere may be produced. 16 refs.

Beahm, E.C.; Weber, C.F.; Kress, T.S.; Parker, G.W.

1991-01-01

402

Iodine - Its possible role in tropospheric photochemistry  

NASA Technical Reports Server (NTRS)

A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to other inorganic compounds such as IO, HOI, IONO2, and I2. The production of these species and their subsequent recycling back to I can lead to the catalytic removal of tropospheric O3, the enhancement of the NO2/NO ratio, the destruction of HxOy free radicals, and the conversion of HO2 to OH. Ultimately, tropospheric inorganic iodine is removed by heterogeneous processes. Calculations using a numerical model to simulate tropospheric photochemistry indicate that iodine may have a strong impact upon the atmospheric O3-NOx-HxOy system. The magnitude of these effects is dependent upon the value of several uncertain rate constants and the primary source distributions of CH3I and other organic and inorganic iodine compounds.

Chameides, W. L.; Davis, D. D.

1980-01-01

403

Theoretical studies of lasers and converters  

NASA Technical Reports Server (NTRS)

Discussed here is Doppler broadening and its effects upon the stimulated emission cross-section connecting an upper level with a lower level in an iodine laser. The stimulated emission cross section is given. The level transitions for the iodine laser are illustrated as are the relative intensities of these transitions. Also discussed is the Voigt profile, which considers the effect of both Doppler broadening and collision broadening upon the absorption line shape. The equations describing the Voigt profile were added to the continuous flow laser model laser simulation program. The results were compared with the standard absorption profile reported in an earlier study. There seems to be no advantage to using the Voigt profile as the laser power output is relatively insensitive to changes in the absorption cross section at the pressures being considered for a space laser. One disadvantage of using the Voigt profile is the excessive numerical computations required by the additional equations.

Heinbockel, John H.

1991-01-01

404

Chemical template directed iodine patterns on the octadecyltrichlorosilane surface.  

PubMed

A carboxylic-terminated nanometer-scale chemical pattern on an octadecyltrichlorosilane (OTS) surface can guide the deposition and crystallization of iodine, forming an iodine pattern on the chemical pattern. The iodine in the pattern is gel-like when fabricated by the solution-deposit method. In contrast, a dendritic, snowflake-shaped polycrystalline iodine sheet is formed by the vapor-phase condensation method. The data demonstrate that iodine is a good tracing and visualizing agent for studying liquid behavior at the nano scale. The topography of the iodine stain reveals that the "coffee ring" effect can be suppressed by reducing the pattern size and increasing the evaporation rate. The chemical template-bound iodine pattern has an unusually low vapor pressure and it can withstand prolonged baking at elevated temperature, which differs significantly from bulk iodine crystals. PMID:18044938

Cai, Yuguang

2008-01-01

405

The Ozone-Iodine-Chlorate Clock Reaction  

PubMed Central

This work presents a new clock reaction based on ozone, iodine, and chlorate that differs from the known chlorate-iodine clock reaction because it does not require UV light. The induction period for this new clock reaction depends inversely on the initial concentrations of ozone, chlorate, and perchloric acid but is independent of the initial iodine concentration. The proposed mechanism considers the reaction of ozone and iodide to form HOI, which is a key species for producing non-linear autocatalytic behavior. The novelty of this system lies in the presence of ozone, whose participation has never been observed in complex systems such as clock or oscillating reactions. Thus, the autocatalysis demonstrated in this new clock reaction should open the possibility for a new family of oscillating reactions. PMID:24386257

Sant'Anna, Rafaela T. P.; Monteiro, Emily V.; Pereira, Juliano R. T.; Faria, Roberto B.

2013-01-01

406

Design of TEM00 mode side-pumped Nd:YAG solar laser  

NASA Astrophysics Data System (ADS)

An alternative solar laser pumping approach is here proposed to improve substantially TEM00 mode solar laser power. The solar radiation is both collected and concentrated by four Fresnel lenses, and redirected towards a laser head by four plane folding mirrors. A secondary concentrator with four semi-cylindrical fused silica lenses is designed to compress the highly concentrated solar radiation to a Nd:YAG single-crystal rod. Optimum pumping conditions and laser resonator parameters are found through ZEMAX© and LASCAD© numerical analysis. The proposed design offers a uniform absorbed pump distribution along the laser rod which has a minimum in its central region, reducing considerably thermal lensing effects. High order mode laser power of 83 W is numerically attained with a short symmetric laser resonant cavity, leading to high collection efficiency of 20.8 W/m2 for side-pumped Nd:YAG solar laser. Large spatial overlap between the pumped volume and the fundamental mode volume is found for an asymmetric laser resonator with concave end mirrors of large radius of curvature. 47.4 W TEM00 laser output power is numerically achieved, leading to a solar laser beam brightness figure of merit of 32 W. This value is 16.8 times more than the previous record for solar-pumped laser.

Almeida, Joana; Liang, Dawei

2014-12-01

407

Hyperfine Interactions in Molecular Iodine  

Microsoft Academic Search

The hyperfine structure of eleven optical transitions in the molecules I1272 and I1292 was resolved by the technique of laser-saturated absorption. All the absorption lines correspond to transitions between the 1Sigma+g(X) and the 3Pi+0u(B) electronic states, but the rotational and vibrational quantum numbers varied widely. Two distinct types of hyperfine interaction were observed: (i) a nuclear electric quadrupole coupling which

M. D. Levenson; A. L. Schawlow

1972-01-01

408

Iodine stability in salt double-fortified with iron and iodine.  

PubMed

Deficiencies in small quantities of micronutrients, especially iodine and iron, severely affect more than a third of the world's population, resulting in serious public health consequences, especially for women and young children. Salt is an ideal carrier of micronutrients. The double fortification of salt with both iodine and iron is an attractive approach to the reduction of both anemia and iodine-deficiency disorders. Because iodine is unstable under the storage conditions found during the manufacturing, distribution, and sale of salt in most developing countries, the effects of packaging materials and environmental conditions on the stability of salt double-fortified with iron and iodine were investigated. Salt was double-fortified with potassium iodide or potassium iodate and with ferrous sulfate or ferrous fumarate. The effects of stabilizers on the stability of iodine and iron were followed by storing the salt under three conditions that represent the extremes of normal distribution and sale for salt in developing countries: room temperature (25 degrees C) with 50%-70% relative humidity, 40 degrees C with 60% relative humidity, and 40 degrees C with 100% relative humidity. The effects of stabilizers, such as sodium hexametaphosphate (SHMP), calcium carbonate, calcium silicate, and dextrose were investigated. None of the combinations of iron and iodine compounds was stable at elevated temperatures. Essentially all of the iodine was lost over a period of six months. SHMP effectively slowed down the iodine loss, whereas magnesium chloride, a typical hygroscopic impurity, greatly accelerated this process. Calcium carbonate did not have a sparing effect on iodine, despite contrary indications in the literature. Ferrous sulfate-fortified salts generally turned yellow and developed an unpleasant rusty flavor. Salt fortified with ferrous fumarate and potassium, iodide was reasonably stable and maintained its organoleptic properties, making it more likely to be acceptable to consumers. We confirmed that application of the iodine compounds as solutions resulted in a more even distribution of the iodine throughout the sample. The effect of the packaging materials was overshadowed by the other variables. None of the packaging materials was clearly better than any other. This may have been due to the fact that the polymer bags were not heat sealed, and thus some moisture penetration was possible. The results indicate that with careful control of processing, packaging, and storage conditions, a double-fortified salt could be stabilized for the six-month period required for distribution and consumption. Unfortunately, the processing and storage required are difficult to attain under typical conditions in developing countries. PMID:12094670

Diosady, L L; Alberti, J O; Ramcharan, K; Mannar, M G Venkatesh

2002-06-01

409

Oxidative stress increased in pregnant women with iodine deficiency.  

PubMed

Iodine is an essential element trace for the synthesis of maternal thyroid hormones needed to support normal fetal development; it also acts as an antioxidant directly or induce antioxidant enzymes indirectly. Iodine deficiency and oxidative stress are associated with pregnancy complications. This study aimed to assess the urinary iodine concentration and its relationship with the antioxidant and oxidative stress status during gestation. Pregnant women were consecutively recruited from an obstetric clinic during all gestation trimesters, and urinary iodine concentration, antioxidant, and oxidative stress were determined. Results showed that 70 % of pregnant women have optimal iodine levels (150-200 ?g/L), while approximately 30 % showed mild iodine deficiency (50-99 ?g/L). Oxidative stress was significantly higher, and the antioxidant status was also compromised as evidenced by decreased total antioxidant status and superoxide dismutase (SOD) activity in pregnant women with mild iodine deficiency than pregnant women with optimal iodine levels. Significant positive correlations were noted between optimal iodine levels and total antioxidant status. Oxidative stress was significantly correlated with mild iodine deficiency. However, no significant correlation was found between iodine levels and SOD and catalase activities. In conclusion, for the first time, these data suggest a correlation between iodine levels and the antioxidant status during pregnancy. PMID:24464603

Vidal, Zendy Evelyn Olivo; Rufino, Sergio Cuellar; Tlaxcalteco, Esteban Hernández; Trejo, Cirenia Hernández; Campos, Raúl Martínez; Meza, Mónica Navarro; Rodríguez, Rocío Coutiño; Arroyo-Helguera, Omar

2014-03-01

410

Reactive iodine species in a semi-polluted environment  

Microsoft Academic Search

Iodine chemistry in the marine boundary layer has attracted increasing attention over the last few years because iodine oxides cause ozone destruction, change the atmospheric oxidising capacity, and can form ultrafine particles. However, the chemistry of iodine in polluted environments is not well understood: its effects are assumed to be inhibited by reactions involving NOx (NO2 & NO). This paper

Anoop S. Mahajan; Hilke Oetjen; Alfonso Saiz-Lopez; James D. Lee; Gordon B. McFiggans; John M. C. Plane

2009-01-01

411

A quantitative model of the biogeochemical transport of iodine  

NASA Astrophysics Data System (ADS)

Iodine deficiency disorders (IDD) are among the world’s most prevalent public health problems yet preventable by dietary iodine supplements. To better understand the biogeochemical behavior of iodine and to explore safer and more efficient ways of iodine supplementation as alternatives to iodized salt, we studied the behavior of iodine as it is absorbed, accumulated and released by plants. Using Chinese cabbage as a model system and the 125I tracing technique, we established that plants uptake exogenous iodine from soil, most of which are transported to the stem and leaf tissue. The level of absorption of iodine by plants is dependent on the iodine concentration in soil, as well as the soil types that have different iodine-adsorption capacity. The leaching experiment showed that the remainder soil content of iodine after leaching is determined by the iodine-adsorption ability of the soil and the pH of the leaching solution, but not the volume of leaching solution. Iodine in soil and plants can also be released to the air via vaporization in a concentration-dependent manner. This study provides a scientific basis for developing new methods to prevent IDD through iodized vegetable production.

Weng, H.; Ji, Z.; Weng, J.

2010-12-01

412

Proceedings of the XIII International Symposium on Gas Flow and Chemical Lasers and High Power Laser Conference, Florence, Italy 18-22 September 2000, The Int. Soc. for Opt. Eng. Vol. 4184, P.O. Box 10, Bellingham, WA 98227-0010, pp. 40-44.  

E-print Network

generator technologies are needed to allow chemical oxygen-iodine laser (COIL) systems to achieve their full 10, Bellingham, WA 98227-0010, pp. 40-44. ElectriCOIL: An Advanced Chemical Iodine Laser Concept attributes. Preliminary analysis and modeling of the ElectriCOIL system concept is presented. ElectriCOIL

Carroll, David L.

413

An iodine mass-balance for Lake Constance, Germany: Insights into iodine speciation changes and fluxes  

NASA Astrophysics Data System (ADS)

Lake Constance is one of Europe's largest oligotrophic lakes and provides a water source for more than 4.5 million people in Germany and Switzerland. We present here a 12 month study on iodine concentrations, speciation and fluxes to and from the lake to gain a quantitative understanding of the limnic iodine cycle. Monthly water samples were obtained from all major tributaries (14) and the outflow to construct a mass-balance model. Sediment traps were also deployed in the lake for two years at two different stations. Total soluble iodine (TSI) in aqueous samples were analysed by ICP-MS and speciation (iodide, iodate and soluble organically bound iodine, SOI) by ion chromatography-ICP-MS. Iodine concentrations in the Alpine tributaries (1-2 ?g l -1) decreased over the summer months due to increasing proportions of snow and glacial melt water from the Alps, while iodine levels in the lowland rivers (˜2-10 ?g l -1) increased over the summer. Deposition of TSI to the catchment (16,340 kg I yr -1) was similar to the TSI out-flux by rivers (16,000 kg I yr -1). By also including the particulate riverine iodine flux out of the catchment (˜12,350 kg I yr -1) it is shown that the catchment is a net source of iodine, with the highest particulate fluxes coming from the Alpine rivers. The total TSI flux to the lake was 16,770 kg I yr -1, the largest proportion coming from the Alpenrhein (43%), followed by the Schussen (8%) and Bregenzer Ach (7.7%). Overall the mass-balance for TSI in the lake was negative, with more iodine flowing out of the lake than in (-2050 kg I yr -1; 12% of TSI in-flux). To maintain mass-balance, 8.8 ?g I m -2 d -1 from the Obersee and 23 ?g I m -2 d -1 from the Untersee must be released from the sediments into the water column. Thus, in comparison with the total iodine flux to the sediments measured by the sediment traps (4762-8075 kg I yr -1), up to 39% of the deposited iodine may be mobilised back into the lake. SOI was the dominant iodine fraction entering the lake, with a total flux of 10,290 kg I yr -1 (64% of TSI input), followed by iodate (3120 kg I yr -1) and iodide (2760 kg I yr -1). Net formation of SOI from iodide and iodate was also noted within the lake, with an estimated production of 6560 kg I yr -1, suggesting a strong role for biology in iodine cycling. In conclusion, organically bound iodine was the dominant iodine species in aqueous and solid phases in Lake Constance, despite low DOC concentrations (<2 mg l -1), and thus is expected to play an important role in iodine cycling in most freshwater environments.

Gilfedder, B. S.; Petri, M.; Wessels, M.; Biester, H.

2010-06-01

414

Source And Sink Of Iodine For Drinking Water  

NASA Technical Reports Server (NTRS)

Proposed system for controlling concentration of iodine in potable water exploits temperature dependence of equilibrium partition of iodine between solution in water and residence in ion-exchange resin. Used to maintain concentration of iodine sufficient to kill harmful microbes, but not so great to make water unpalatable. Requires little attention, yet controls concentration of iodine more precisely than iodination and deiodination by manual techniques. Conceived for use aboard spacecraft, system has terrestrial applications in regions where water must be kept potable, resupply difficult, and system must operate largely unattended.

Sauer, Richard L.; Flanagan, David T.; Gibbons, Randall E.

1991-01-01

415

Iodine balance studies in protein-calorie malnutrition  

PubMed Central

In 12 malnourished Senegalese children iodine intake and excretion were measured on admission for 4 consecutive days. All subjects were in negative iodine balance, averaging -20·5 ?g iodine/day. One month later, after nutritional rehabilitation, 7 children resubmitted to comparative balance study showed a strongly positive balance of +19·3 ?g iodine/day. Protein-calorie malnutrition is characterized by a continuous impoverishment of the thyroid's iodine content, while clinical recovery is accompanied by a progressive restoration. PMID:4208456

Ingenbleek, Yves; Malvaux, Paul

1974-01-01

416

Iodine Revolatilization in a Grand Gulf Loca  

SciTech Connect

The TRENDS models are applied at each time step to each control volume. Significant amounts of water occur only in the wetwell and drywell sump (the refueling pool is not a factor, as discussed earlier). In Fig. 2, we show the radiolytic acid production feeding into each of these pools. Since the water is initially neutral and no chemical additives are present, the acid additions are the major factors affecting pH. In Fig. 3, we see the downward trend of pH resulting from these acid additions. The conversion of iodide (I{sup {minus}}) to molecular iodine (I{sub 2}) is most noticeable in the wetwell, since this is the repository of most iodide and HCl. Gradually, during the transient small amounts of more volatile iodine are formed. While iodide remains the dominant form, noticeable amounts of I{sub 2} and intermediate species are created. Once produced in water, some I{sub 2} is free to evaporate into airspace. Fig. 4 indicates the increase in all airborne iodine throughout the transient. This is compared to the MELCOR result for CsI aerosol, which decreases dramatically due to containment sprays. The I{sub 2} in the airspace can be vented to the enclosure building or the environment. In the present accident sequence, the only path to the environment was through the SGTS, which was assumed to operate as in MELCOR. However, both are dwarfed by the MELCOR gaseous release during the first 12 h because MELCOR does not model spray washout of gaseous iodine. Steadily increasing throughout the transient, the revolatilization release is eventually more than an order-or-magnitude higher than the MELCOR aerosol release. Also, 99% of iodine flowing directly through the SGTS was retained in filters. The remaining 1% was released to the environment. In addition, a small flow bypassing the SGTS filters vented directly into the environment. The total released from these two paths is shown in Fig. 5.

Beahm, E.C.; Weber, C.F.

1999-01-01

417

Re-emergence of iodine deficiency in Australia.  

PubMed

Iodine is an essential nutrient for human growth and development. The thyroid gland is dependent upon iodine for production of thyroid hormone. It is a common perception that iodine deficiency is not a major public health concern in mainland Australia, with sporadic studies carried out about a decade ago showing average urinary iodine excretion levels of around 200 microg/day. Recent evidence, however, has shown that the consumption of iodine is declining in Australia. A similar situation has occurred in the USA. The present study was designed to evaluate the urinary iodine excretion (UIE), as the indicator of iodine nutrition, in samples obtained from various demographic groups in the Sydney metropolitian area, namely: schoolchildren, healthy adult volunteers. pregnant women and patients with diabetes. Urinary iodine in spot urine sample was measured in a Technicon II autoanalyser using an in-house, semiautomated method. The results in this communication show that all four study groups had the median UIE below 100 microg/L. the criteria set by the World Health Organization for iodine repletion, and confirm what has been described previously, that iodine deficiency has reemerged in Sydney, Australia. One of the major causes of the reduced iodine intake is the reduction of iodine in milk since the dairy industry replaced iodine-rich cleaning solutions with other sanitisers. Secondly, less than 10% of the population are currently using iodised salt. A national survey into the iodine nutrition status in Australia is urgently required as part of the establishment of a systematic surveillance and legislation is required to iodise all edible salt. PMID:11708309

Li, M; Ma, G; Boyages, S C; Eastman, C J

2001-01-01

418

Proceedings of the International Conference on Lasers '99, ed. V.J. Corcoran, STS Press, McLean VA, 2000, pp. 69-77. ADVANCED MIXING NOZZLE CONCEPTS FOR COIL  

E-print Network

-iodine laser (COIL) that will significantly improve the chemical efficiency of such systems. It is believed are needed to allow chemical oxygen-iodine laser (COIL) systems to achieve their full potential as efficient will have major implications for the military programs as well as evolving industrial COIL systems. Research

Carroll, David L.

419

Proceedings of the International Conference on Lasers 2000, eds. V.J. Corcoran and T.A. Corcoran, STS Press, McLean VA, 2001, pp. 265-272.  

E-print Network

oxygen-iodine laser (COIL) singlet oxygen generator (SOG) based on discharge excitation of molecular the O2(1 S) concentrations. I. INTRODUCTION The classical chemical oxygen-iodine laser (COIL) operates by electrical means. A new kind of continuous wave COIL device is proposed: an Electrically assisted Chemical

Carroll, David L.

420

Long-term migration of iodine in sedimentary rocks based on iodine speciation and 129I/127I ratio  

NASA Astrophysics Data System (ADS)

[Introduction] 129I is one of the available indexes of long-term migration of groundwater solutes, because of its long half-life (15.7 million years) and low sorption characteristics. The Horonobe underground research center (Japan Atomic Energy Agency), at which are conducted research and development of fundamental techniques on geological disposal of high-level radioactive waste, is an appropriate site for natural analogue studies, because iodine concentration in groundwater is high in this area. To predict iodine behavior in natural systems, speciation of iodine is essential because of different mobility among each species. In this study, we determined iodine speciation and129I/127I isotope ratios of rock and groundwater samples to investigate long term migration of iodine. [Methods] All rock and groundwater samples were collected at Horonobe underground research center. The region is underlain mainly by Neogene to Quaternary marine sedimentary rocks, the Wakkanai Formation (Wk Fm, siliceous mudstones), and the overlying Koetoi Formation (Kt Fm, diatomaceous mudstones). Iodine species in rock samples were determined by iodine K-edge X-ray absorption near edge structure (SPring-8 BL01B1). Thin sections of rock samples were prepared, and iodine mapping were obtained by micro-XRF analysis (SPring-8 BL37XU). Iodine species (IO3-, I-, and organic I) in groundwater were separately detected by high performance liquid chromatography connected to ICP-MS. The 129I/127I ratios in groundwater and rock samples were measured by accelerator mass spectrometry (MALT, Univ. of Tokyo). Iodine in rock samples were separated by pyrohydrolysis and water extraction. [Results and discussion] Concentration of iodine in groundwater varied widely and was much higher than that of seawater showing a high correlation with that of chlorine (R2 = 0.90). Species of iodine in groundwater was mainly I-. Iodine in rock samples decreased near the boundary between Wk and Kt Fms. Iodine K-edge XANES showed that iodine in rock was a mixture of organic and inorganic iodine. According to iodine and carbon mapping in micrometer scale, iodine was accumulated locally and correlated with carbon, suggesting that iodine existed as organic iodine. The 129I/127I isotope ratios in groundwater were lower than those in rocks and almost constant at various depths, demonstrating that iodine in groundwater was released from layers deeper than co-existing rocks. According to these results, migration of iodine in this area can be expected as follows. (i) During sedimentation of Wk and Kt Fms, iodine was accumulated as organic iodine in siliceous sediments. (ii) Iodine was released as I- from the layers deeper than Wk Fm during diagenetic processes. Subsequently, iodine rich groundwater was distributed to Wk and Kt Fms due to the compaction of the layers. (iii) During uplift and denudation processes, both iodine and chlorine were diluted by meteoric water from the surface. Iodine distribution coefficient (Kd = [I concentration in rock]/[I concentration in groundwater]) of Kt Fm is higher than that in Wk Fm. Diatomaceous mudstones might be more effective than siliceous mudstones as natural barrier for 129I released from deep underground radioactive waste repository. This suggestion should be reinforced by laboratory experiments in future studies.

Togo, Y.; Takahashi, Y.; Amano, Y.; Matsuzaki, H.; Suzuki, Y.; Muramatsu, Y.; Iwatsuki, T.

2012-12-01

421

Iodine excretion has decreased in Denmark between 2004 and 2010 - the importance of iodine content in milk.  

PubMed

Fortification with the essential trace element iodine is widespread worldwide. In the present study, results on iodine excretion and intake of iodine-rich foods from a cross-sectional study carried out in 2004-5, 4 to 5 years after the implementation of mandatory iodine fortification, were compared with data in a study carried out in 2008-10. The 2008-10 study was a follow-up of a cross-sectional study carried out before iodine fortification was implemented. Participants in the cross-sectional studies were randomly selected. Both studies were carried out in the cities of Aalborg and Copenhagen in Denmark. The median urinary iodine concentration decreased in women from 97 ?g/l (n 2862) to 78 ?g/l (n 2041) (P< 0·001). The decrease persisted after adjustment for age, city and education, and if expressed as estimated 24 h iodine excretion. The prevalence of users of iodine containing dietary supplements increased from 29·4 to 37·3 % (P< 0·001). The total fluid intake increased in women (P< 0·001), but the intake of other iodine-rich foods did not change. The median urinary iodine concentration did not change in men (114 ?g/l (n 708) and 107 ?g/l (n 424), respectively), while the total fluid intake decreased (P= 0·001). Iodine content was measured in milk sampled in 2000-1 and in 2013. The iodine content was lower in 2013 (12 (sd 3) ?g/100 g) compared with that in 2000-1 (16 (sd 6) ?g/100 g) (P< 0·001). In conclusion, iodine excretion in women has decreased below the recommended level. The reason might probably, at least partly, be a decreased content of iodine in milk. PMID:25354521

Rasmussen, Lone B; Carlé, Allan; Jørgensen, Torben; Knuthsen, Pia; Krejbjerg, Anne; Perrild, Hans; Bjergved, Lena; Sloth, Jens J; Laurberg, Peter; Ovesen, Lars

2014-12-01

422

[Dietary iodine deficiency in East Germany following introduction of interdisciplinary preventive use of iodine].  

PubMed

The interdisciplinary iodine prophylaxis introduced in 1985/86 comprises the iodination of 84% of the packaged salt with 32 mg KIO3/kg salt and the use of iodized mixtures of mineral substances in animal production. At the beginning of this measure with an average renal ioduria of 19.0 +/- 1.0 micrograms J/g creatinine in the GDR there was at least still an iodine deficiency of 2nd degree. It increased from north to south: 20.3 +/- 1.0 in contrast 13.4 +/- 1.5 micrograms J/g creatinine. In the middle of 1986 a clear improvement of the supply with iodine began. The renal iodurias had more than doubled. For the GDR the mean ioduria was 43.4 +/- 0.9. The relation from north to south had, if anything, inverted: 37.3 +/- 2.1 in the north, 42-49 micrograms J/g creatinine in the centre and south of the GDR. Nearly one third of the population no more undergoes an iodine deficiency. The intrathyroidal iodine content increases. The improved supply with iodine among others is evident in: reduction of the connatal goiter below 1%, reduction of the recall rate in the TSH hypothyroidism newborn screening, normal thyroid gland mass of the newborn, reduction of the goiter frequency in children and adolescents, transient increase of the frequency of hyperthyroidism, in particular based on functional autonomies in persons older than forty years. In animal production losses of produce amounting to 181 Mic/a were eliminated. PMID:2330738

Bauch, K; Seitz, W; Förster, S; Keil, U

1990-01-01

423

Industrial COIL systems--part 2: gas-laser cutting  

Microsoft Academic Search

First results of experimental and theoretical investigations concerning an industrial application of oxygen-iodine laser (COIL) are reported. The dependencies of the largest cut depth on the laser emission power, cut width and rate, and kind of processing gas (oxygen or nitrogen) were determined for carbon and stainless steels, and aluminium alloys. A developed simple engineering model determines parameters of separating

Yury V. Kolobyanin; Il'ya A. Bulatkin; Vladimir V. Kalinovskiy; Vladimir V. Konovalov; Vladimir B. Moiseev; Victor D. Nickolaev; Lev N. Shornikov; Roman E. Sobolev; Boris A. Vyskubenko

2005-01-01

424

Progress report on the development of a repetitively pulsed frequency-shifted COIL laser  

NASA Astrophysics Data System (ADS)

This paper summarizes recent progress that has occurred in several research areas related to the development of a repetitively-pulsed, frequency-shifted chemical oxygen iodine laser (COIL). COIL gain- switch experiments at 10 kHz pulse rates are described using a novel solid state pulsed magnetic field system. Raman conversion experiments in hydrogen using a pulsed photolytic iodine laser as a COIL surrogate are also described.

Hager, Gordon D.; Anderson, Brian T.; Kendrick, Kip R.; Tate, Ralph F.; Helms, Charles A.; Adler, Richard J.; Fisher, Charles H.; Brown, Andrew J.; Plummer, David N.

2000-08-01

425

Progress report on the development of a repetitively pulsed frequency-shifted COIL laser  

Microsoft Academic Search

This paper summarizes recent progress that has occurred in several research areas related to the development of a repetitively-pulsed, frequency-shifted chemical oxygen iodine laser (COIL). COIL gain- switch experiments at 10 kHz pulse rates are described using a novel solid state pulsed magnetic field system. Raman conversion experiments in hydrogen using a pulsed photolytic iodine laser as a COIL surrogate

Gordon D. Hager; Brian T. Anderson; Kip R. Kendrick; Ralph F. Tate; Charles A. Helms; Richard J. Adler; Charles H. Fisher; Andrew J. Brown; David N. Plummer

2000-01-01

426

Kinetics of the electrical discharge pumped oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A systematic study of microwave discharges at 2.45 GHz has been performed through the pressure range of sustainable electric discharges in pure oxygen flows of 2 to 10 Torr. A corresponding study of 13.56 MHz has also been performed at pressures of 2, 4, and 7 Torr. Optical emissions from O2( a),O2(b), and O-atoms have been measured from the center of a microwave discharge. Discharge residence times from 0.1 to 5 ms have been reported, establishing that gas temperatures arrive at stationary values within the first 0.3 ms upon entering the discharge region. The O2(b) emissions, with a spectral resolution of 0.01 nm, have been used to measure the temperature of the gas, which typically reaches a steady-state of 1,200 K. A theoretical description of the gas heating is fit to measured temperatures, which determines that the fraction of discharge energy coupled into gas heating is 17 +/- 2%. The yield of O2( a) comes to steady-state at all pressures within 1 ms of entering the discharge region. The interpretation of the measured yield, using a streamlined, nearly analytic model, cast new light on the kinetics within the electric discharge. The pseudo-first order quenching rate of O2 (a) ranges from 6,000 1/s for microwave discharges to 600 1/s for radio frequency (RF) discharges, independent of gas pressure and flow rate. The slower decay rate for the RF discharge corresponds with a considerably lower ionization rate. The observations are consistent with a second order reaction channel that is dependent on both the electron and molecular oxygen ground state concentrations. Destruction of the O2 (b) state by direct impact with electrons or atomic oxygen does not adequately describe the observed behavior of O2( a). The role of vibrationally excited ground state oxygen is explored and provides a plausible destruction mechanism.

Lange, Matthew A.

427

Modeling of the all-gas-phase iodine laser (AGIL)  

NASA Astrophysics Data System (ADS)

This work revisits the finite-rate chemistry mechanism for AGIL in light of recent rate measurements for kinetic processes. The effect of temperature dependence of kinetic processes measured only at room temperature conditions is explored by assuming a square-root dependence upon temperature in line with kinetic theory. A sensitivity study is performed to elucidate the relative impact of each chemical kinetic process modeled with respect to the larger set of modeled chemical kinetic processes. And reactant mixing is examined, with documentation of the effects of the reactant mixing predictions upon recent multi-watt power extraction experiments.

Madden, Timothy J.; Manke, Gerald C., II; Hager, Gordon D.

2005-03-01

428

Fractionation analysis of iodine in bovine milk by preconcentration neutron activation analysis  

Microsoft Academic Search

Iodine is an essential trace element for human beings. The main source of iodine is generally food items such as fish and milk. Either the lack or the excess of iodine can cause health problems. There exists an increasing interest in the determination of total iodine as well as various species of iodine in milk. We have developed an epithermal

K. Isaac-Olive; R. Acharya; A. Chatt

2008-01-01

429

Diagnosis of the spot and drift of a cw-COIL laser beam  

Microsoft Academic Search

A dynamic spot diagnostic system has been developed to quantitatively measure the instability of a continuous-wave chemical oxygen iodine laser (CW-COIL). The system can measure the real time changes in drift, vibration of low frequency, intensity profile and spot diameter for the CW- COIL laser beam. The cause that induces the instability of laser beam was tentatively analyzed in this

Chunyan Wang; Jianheng Zhao; Yonghua Yuan; Xufa Liu; Changling Liu

1997-01-01

430

Metal-silicate partitioning of iodine at high pressures and temperatures: Implications for the Earth's core and 129*Xe budgets  

NASA Astrophysics Data System (ADS)

The partition coefficients of iodine Dmet/sil between molten metal and molten silicate were investigated using a Laser Heated Diamond Anvil Cell (LHDAC) at pressures between 2 and 20 GPa and at ~2800 K. No pressure dependence of Dmet/sil was observed within this range, but the composition of the Fe-Ni alloy liquid phase was shown to have an effect. When the metallic liquid was alloyed with S, O and Si, there was an increase in iodine solubility in the metal. Iodine exhibited mildly siderophile behaviour across all the investigated conditions, with Dmet/sil=1.25±0.65 (2 s.d.) (Fe metal system) and Dmet/sil=4.33±1.41 (2 s.d.) (Fe-alloy). In conjunction with a revised bulk silicate Earth (BSE) concentration, it is calculated that the core could be a significant reservoir for iodine, with up to 82% of the bulk Earth's iodine budget in the core, depending on the light element content of the metal phase and the process of core formation. The composition of the metal phase appears to have a greater effect on the partitioning and sequestration of iodine than the style of core segregation. As the core likely formed while 129I was still extant, the core can also be a reservoir for radiogenic 129Xe from the decay system 129I-129Xe (T1/2=15.7 Myr). Preliminary modelling indicates that the decay of 129I in the core has the potential to generate radiogenic 129Xe concentrations that are at least two orders of magnitude greater than what has been estimated for the depleted mantle. While this may have a significant impact on the isotopic signatures of the overlying mantle, it is not yet clear how flux from the core fits within the overall picture of mantle noble gas evolution.

Armytage, Rosalind M. G.; Jephcoat, Andrew P.; Bouhifd, M. A.; Porcelli, Donald

2013-07-01

431

[Is iodination of cooking salt still necessary? Current studies on iodine supply in Switzerland].  

PubMed

Salt with 3.75 mg iodide per kg was introduced in Switzerland stepwise in the individual cantons between 1922 and 1952. The iodide content was raised to 7.5 mg in 1962 and to 15 mg per kg in 1980. 92% of retail salt and 78% of all salt for human consumption (including salt used in industrial food processing) was iodized in 1989. Under this measure, prevalence of grade 1b or larger goiter dropped continuously to a present value of 1.3% in school-children and 0.3% in male army recruits. Endemic cretinism has disappeared completely. Urinary iodine has reached the desired range of 150 +/- 77 (SD) micrograms per g creatinine. The following facts prove that iodization of salt (and not other changes of food habits) have corrected the iodine deficiency in Switzerland: 1. Urinary iodine is highly correlated with urinary sodium. Backward extrapolation yields a theoretical urinary iodine of 30 micrograms per g creatinine in the absence of iodized salt, a value typical of severe deficiency. 2. Goiter prevalence declined later in those cantons which introduced iodized salt last. 3. Surrounding countries without iodized salt (France, Italy, Federal Republic of Germany, Spain) suffer from considerable iodine deficiency with areas of high goiter prevalence and even endemic cretinism. The new data underscore the absolute and continued need for iodized salt in Switzerland. PMID:2028234

Supersaxo, Z; Selz, B; Hasler, P; Wespi, H J; Abelin, T; Bürgi, H

1991-03-01

432

Sensitive monitoring of iodine species in sea water using capillary electrophoresis: vertical profiles of dissolved iodine in the Pacific Ocean.  

PubMed

Using a novel high-sensitivity capillary electrophoretic method, vertical distributions of iodate, iodide, total inorganic iodine, dissolved organic iodine and total iodine in the North Pacific Ocean (0-5500 m) were determined without any sample pre-treatment other than UV irradiation before total iodine analysis. An extensive set of data demonstrated that the iodine behaviour in the ocean water collected during a cruise in the North Pacific Ocean in February-March 2003 was not conservative but correlated with variations in concentrations of dissolved oxygen and nutrient elements such as silicon, nitrogen and phosphorus. This suggests that the vertical distribution of iodine is associated with biological activities. The dissolved organic iodine was found in the euphotic zone in accord with observations elsewhere in the oceans. The vertical profile of dissolved organic iodine also appears to be related to biogeochemical activity. The concentrations of all measured iodine species vary noticeably above 1000 m but only minor latitudinal changes occur below 1000 m and slight vertical alterations can be observed below 2400 m. These findings are thought to reflect the stratification of nutrients and iodine species with different biological activities in the water column. PMID:16049582

Huang, Zhuo; Ito, Kazuaki; Morita, Isamu; Yokota, Kuriko; Fukushi, Keiichi; Timerbaev, Andrei R; Watanabe, Shuichi; Hirokawa, Takeshi

2005-08-01

433

Models of iodine behavior in reactor containments  

SciTech Connect

Models are developed for many phenomena of interest concerning iodine behavior in reactor containments during severe accidents. Processes include speciation in both gas and liquid phases, reactions with surfaces, airborne aerosols, and other materials, and gas-liquid interface behavior. Although some models are largely empirical formulations, every effort has been made to construct mechanistic and rigorous descriptions of relevant chemical processes. All are based on actual experimental data generated at the Oak Ridge National Laboratory (ORNL) or elsewhere, and, hence, considerable data evaluation and parameter estimation are contained in this study. No application or encoding is attempted, but each model is stated in terms of rate processes, with the intention of allowing mechanistic simulation. Taken together, this collection of models represents a best estimate iodine behavior and transport in reactor accidents.

Weber, C.F.; Beahm, E.C.; Kress, T.S.

1992-10-01

434

Complex impedance studies of lithium iodine batteries  

SciTech Connect

Complex impedance spectra of conductivity cells containing iodine/poly-2-vinylpyridine cathode material were taken by two- and four-probe techniques. The impedance spectra contain a current-independent bulk resistance in series with a current-dependent interfacial resistance. The current-dependent interfacial resistance has the characteristics expected of a charge-transfer resistance. Moreover, electronically blocked (lithium/lithium iodide) electrodes give the same result as non-blocked (stainless steel) electrodes. This is exactly what would be expected if the medium were an ionic conductor. Complex impedance spectra of lithium/iodine batteries show additional structure, as might be expected, but are consistent with results from the conductivity cells.

Schmidt, C.L.; Skarstad, P.M. (Promeon Division Medtronic, Inc. Minneapolis, MN (US))

1990-08-01

435

Estimation of salt iodine in Pondicherry District.  

PubMed

A cross sectional survey was conducted in 2005 among 358 school children from 8 communities in the district of Pondicherry to assess the iodine content of salt at consumer level. School children were asked to bring salt consumed at their houses and 290 salt samples could finally be analysed. Only 26.2% of the population in the district were found to consume salt with more than 15 ppm iodine. Consumption of non-iodised salt was more in rural areas (96.4%) as compared to urban areas (71.3%). 39 salt samples from different retail shops in Pondicherry showed a mean value of 35.6+/-10.7 ppm. PMID:18232155

Mohanty, B; Basu, S; Sarkar, Sonali

2007-01-01

436

The impact of iodine supplementation and bread fortification on urinary iodine concentrations in a mildly iodine deficient population of pregnant women in South Australia.  

PubMed

Mild iodine deficiency during pregnancy can have significant effects on fetal development and future cognitive function. The purpose of this study was to characterise the iodine status of South Australian women during pregnancy and relate it to the use of iodine-containing multivitamins. The impact of fortification of bread with iodized salt was also assessed. Women (n?=?196) were recruited prospectively at the beginning of pregnancy and urine collected at 12, 18, 30, 36 weeks gestation and 6 months postpartum. The use of a multivitamin supplement was recorded at each visit. Spot urinary iodine concentrations (UIC) were assessed. Median UICs were within the mildly deficient range in women not taking supplements (<90 ?g/L). Among the women taking iodine-containing multivitamins UICs were within WHO recommendations (150-249 ?g/L) for sufficiency and showed an increasing trend through gestation. The fortification of bread with iodized salt increased the median UIC from 68 ?g/L to 84 ?g/L (p?=?.011) which was still in the deficient range. Pregnant women in this region of Australia were unlikely to reach recommended iodine levels without an iodine supplement, even after the mandatory iodine supplementation of bread was instituted in October 2009. PMID:23497409

Clifton, Vicki L; Hodyl, Nicolette A; Fogarty, Paul A; Torpy, David J; Roberts, Rachel; Nettelbeck, Ted; Ma, Gary; Hetzel, Basil

2013-01-01

437

Antibacterial iodine-supported titanium implants  

Microsoft Academic Search

Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti–I2) and its impact on post-implant infection, as well as determining the potential suitability of Ti–I2 as a biomaterial. External fixation pins were

T. Shirai; T. Shimizu; K. Ohtani; Y. Zen; M. Takaya; H. Tsuchiya

2011-01-01

438

Therapeutic implications of iodine-125 cytotoxicity  

SciTech Connect

The biological consequences of differential subcellular radionuclide accumulation within nuclear structures have important implications for the design and development of new therapeutic agents for cancer management. A growing body of experimental data demonstrates that localization of /sup 125/I within the genome results in marked cytotoxicity. Investigations of iodine-125 labeled iododeoxyuridine, DNA intercalators and tamoxifen are reviewed as representative of this new group of potential radiotherapeutic agents.

Bloomer, W.D.; McLaughlin, W.H.; Adelstein, S.J.

1982-11-01

439

Therapeutic implications of iodine-125 cytotoxicity  

SciTech Connect

The biological consequences of differential subcellular radionuclide accumulation within nuclear stuctures have important implications for the design and development of new therapeutic agents for cancer management. A growing body of experimental data demonstrates that localization of /sup 125/I within the genome results in marked cytotoxicity. Investigations of iodine-125 labeled iododeoxyuridine, DNA intercalators and tamoxifen are reviewed as representative of this new group of potential radiotherapeutic agents.

Bloomer, W.D.; McLaughlin, W.H.; Adelstein, S.J.

1982-11-01

440

Air Density Measurements in a Mach 10 Wake Using Iodine Cordes Bands  

NASA Technical Reports Server (NTRS)

An exploratory study designed to examine the viability of making air density measurements in a Mach 10 flow using laser-induced fluorescence of the iodine Cordes bands is presented. Experiments are performed in the NASA Langley Research Center 31 in. Mach 10 air wind tunnel in the hypersonic near wake of a multipurpose crew vehicle model. To introduce iodine into the wake, a 0.5% iodine/nitrogen mixture is seeded using a pressure tap at the rear of the model. Air density was measured at 56 points along a 7 mm line and three stagnation pressures of 6.21, 8.62, and 10.0 MPa (900, 1250, and 1450 psi). Average results over time and space show rho(sub wake)/rho(sub freestream) of 0.145 plus or minus 0.010, independent of freestream air density. Average off-body results over time and space agree to better than 7.5% with computed densities from onbody pressure measurements. Densities measured during a single 60 s run at 10.0 MPa are time-dependent and steadily decrease by 15%. This decrease is attributed to model forebody heating by the flow.

Balla, Robert J.; Everhart, Joel L.

2012-01-01

441

Iodine deficiency disorders (IDD) control in India  

PubMed Central

Iodine deficiency disorders (IDD) constitute the single largest cause of preventable brain damage worldwide. Majority of consequences of IDD are invisible and irreversible but at the same time these are preventable. In India, the entire population is prone to IDD due to deficiency of iodine in the soil of the subcontinent and consequently the food derived from it. To combat the risk of IDD, salt is fortified with iodine. However, an estimated 350 million people do not consume adequately iodized salt and, therefore, are at risk for IDD. Of the 325 districts surveyed in India so far, 263 are IDD-endemic. The current household level iodized salt coverage in India is 91 per cent with 71 per cent households consuming adequately iodized salt. The IDD control goal in India was to reduce the prevalence of IDD below 10 per cent in the entire country by 2012. What is required is a “mission approach” with greater coordination amongst all stakeholders of IDD control efforts in India. Mainstreaming of IDD control in policy making, devising State specific action plans to control IDD, strict implementation of Food Safety and Standards (FSS) Act, 2006, addressing inequities in iodized salt coverage (rural-urban, socio-economic), providing iodized salt in Public Distribution System, strengthening monitoring and evaluation of IDD programme and ensuring sustainability of IDD control activities are essential to achieve sustainable elimination of IDD in India. PMID:24135192

Pandav, Chandrakant S.; Yadav, Kapil; Srivastava, Rahul; Pandav, Rijuta; Karmarkar, M.G.

2013-01-01

442

Radioactive iodine therapy in cats with hyperthyroidism  

SciTech Connect

Eleven cats with hyperthyroidism were treated with radioactive iodine (/sup 131/I). Previous unsuccessful treatments for hyperthyroidism included hemithyroidectomy (2 cats) and an antithyroid drug (7 cats). Two cats had no prior treatment. Thyroid scans, using technetium 99m, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 5 cats and in both lobes in 6 cats. Serum thyroxine concentrations were high and ranged from 4.7 to 18 micrograms/dl. Radioactive iodine tracer studies were used to determine peak radioactive iodine uptake (RAIU) and effective and biological half-lives. Activity of /sup 131/I administered was calculated from peak RAIU, effective half-life, and estimated thyroid gland weight. Activity of /sup 131/I administered ranged from 1.0 to 5.9 mCi. The treatment goal was to deliver 20,000 rad to hyperactive thyroid tissue. However, retrospective calculations based on peak RAIU and effective half-life obtained during the treatment period showed that radiation doses actually ranged from 7,100 to 64,900 rad. Complete ablation of the hyperfunctioning thyroid tissue and a return to euthyroidism were seen in 7 cats. Partial responses were seen in 2 cats, and 2 cats became hypothyroid. It was concluded that /sup 131/I ablation of thyroid tumors was a reasonable alternative in the treatment of hyperthyroidism in cats. The optimal method of dosimetry remains to be determined.

Turrel, J.M.; Feldman, E.C.; Hays, M.; Hornof, W.J.

1984-03-01

443

LASERS: Self-initiating volume discharge in iodides used for producing atomic iodine in pulsed chemical oxygen --- iodine lasers  

Microsoft Academic Search

A volume self-sustained discharge (VSD) in iodides (C3H7I, C4H9I) and in their mixtures with SF6, N2, and O2 in the presence of small-scale inhomogeneities on the cathode surface is shown to develop in the form of a self-initiating volume discharge (SIVD), i.e., a volume discharge without any preionisation including discharge gaps with a strong edge enhancement of the electric field.

A. A. Belevtsev; S. Yu Kazantsev; A. V. Saifulin; K. N. Firsov

2003-01-01

444

Automated Iodine Monitoring System development (AIMS). [shuttle prototype  

NASA Technical Reports Server (NTRS)

The operating principle of the automated iodine monitoring/controller system (AIMS) is described along with several design modifications. The iodine addition system is also discussed along with test setups and calibration; a facsimile of the optical/mechanical portion of the iodine monitor was fabricated and tested. The appendices include information on shuttle prototype AIMS, preliminary prime item development specifications, preliminary failure modes and effects analysis, and preliminary operating and maintenance instructions.

1975-01-01

445

Iodine content in drinking water and other beverages in Denmark  

Microsoft Academic Search

Objective: To investigate the variation in iodine content in drinking water in Denmark and to determine the difference in iodine content between organic and non-organic milk. Further, to analyse the iodine content in other beverages.Design and setting: Tap water samples were collected from 41 evenly distributed localities in Denmark. Organic and non-organic milk was collected at the same time (twice

LB Rasmussen; EH Larsen; L Ovesen

2000-01-01

446

Urinary iodine percentile ranges in the United States  

PubMed Central

Background The status of iodine nutrition of a population can be determined by measurement of urinary iodine concentrations since it is thought to indicate dietary iodine intake. Normally, these results are compared to population-based criteria, since there are no reference ranges for urinary iodine. Objective To determine the percentile ranges for urinary iodide (UI) concentrations in normal individuals in the United States. Materials and methods The third National Health and Nutrition Examination Survey (NHANES III) (1988–1994) database of the civilian, non-institutionalized, iodine-sufficient US population was used. The 2.5th to 97.5th percentile ranges for urinary iodine and for urinary iodine per gram creatinine ratio (UI/Cr) (?g/g) were calculated for females and males, 6–89 years of age, each stratified by age groups. Results and conclusions We calculated the percentile ranges for urinary iodine. After exclusions of subjects with goiter or thyroid disease, the study sample included 21,530 subjects; 10,439 males and 11,091 females. For women of childbearing age (14–44 years), urinary iodine concentration 2.5th to 97.5th percentiles are 1.8–65 ?g/dl or 36–539 ?g/g creatinine. For pregnant women, the ranges are 4.2–55 ?g/dl or 33–535 ?g/g creatinine. PMID:12559616

Soldin, Offie Porat; Soldin, Steven J.; Pezzullo, John C.

2013-01-01

447

Gravimetric determination of the iodine number of carbon black  

SciTech Connect

This paper discusses a gravimetric method for the determination of the iodine adsorption number of carbon black. It comprises determining the concentration of an accurately weighed iodine blank solution by adding a standardized titrant to the iodine solution until a titration endpoint is reached and determining the concentration of the iodine solution by accurately weighing the amount of the standardized titrant necessary to reach the endpoint, accurately weighing an amount of carbon black and adding an appropriate amount of an accurately weighed portion of the iodine solution, equilibrating the carbon black-iodine solution mixture, adding the standardized titrant to an accurately weighed portion of the supernatant from the carbon black-iodine mixture until a titration endpoint is reached and determining the concentration of the supernatant by accurately weighing the amount of the standardized titrant necessary to reach the endpoint, wherein the titration endpoint of the supernatant is obtained using an indicating and a reference electrode, and calculating the iodine adsorption number of the carbon black based on the gravimetrically determined concentration of the titrant, the iodine solution, and the supernatant.

Murphy, L.J. Jr.

1991-03-26

448

Mission and System Advantages of Iodine Hall Thrusters  

NASA Technical Reports Server (NTRS)

The exploration of alternative propellants for Hall thrusters continues to be of interest to the community. Investments have been made and continue for the maturation of iodine based Hall thrusters. Iodine testing has shown comparable performance to xenon. However, iodine has a higher storage density and resulting higher ?V capability for volume constrained systems. Iodine's vapor pressure is low enough to permit low-pressure storage, but high enough to minimize potential adverse spacecraft-thruster interactions. The low vapor pressure also means that iodine does not condense inside the thruster at ordinary operating temperatures. Iodine is safe, it stores at sub-atmospheric pressure, and can be stored unregulated for years on end; whether on the ground or on orbit. Iodine fills a niche for both low power (<1kW) and high power (>10kW) electric propulsion regimes. A range of missions have been evaluated for direct comparison of Iodine and Xenon options. The results show advantages of iodine Hall systems for both small and microsatellite application and for very large exploration class missions.

Dankanich, John W.; Szabo, James; Pote, Bruce; Oleson, Steve; Kamhawi, Hani

2014-01-01

449

Electronically modified single wall carbon nanohorns with iodine adsorption  

NASA Astrophysics Data System (ADS)

Tailoring electronic properties of single wall carbon nanohorn (SWCNH) is expected to develop the application potential in various fields. SWCNH is efficiently modified with iodine molecules by liquid phase adsorption. The adsorption isotherm of iodine on SWCNH was Langmuirian with the saturated adsorption amount of 185 ± 10 mg g-1 (coverage 0.18), indicating a specific interaction between SWCNH and iodine. The DC electrical conductivity of SWCNH film prepared by dip-coating method increased with the iodine adsorption amount almost by a factor 10.

Khoerunnisa, Fitri; Fujimori, Toshihiko; Itoh, Tsutomu; Kanoh, Hirofumi; Ohba, Tomonori; Yudasaka, Masako; Iijima, Sumio; Kaneko, Katsumi

2011-01-01

450

Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey.  

PubMed

Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n 1311) was 124.1mg/l and 122.6 mg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118.3 mg/l) was significantly lower than that in the third trimester (131.0 mg/l) but significantly higher than among non-pregnant women (84.8 mg/l). Iodine-containing supplement intake was reported by 60.8% of the women and 57.4% of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 mg iodine as recommended. PMID:23084115

Vandevijvere, Stefanie; Amsalkhir, Sihame; Mourri, Ahmed Bensouda; Van Oyen, Herman; Moreno-Reyes, Rodrigo

2013-06-28

451

Method for the simultaneous preparation of Radon-211, Xenon-125, Xenon-123, Astatine-211, Iodine-125 and Iodine-123  

DOEpatents

A method for simultaneously preparing Radon-211, Astatine-211, Xenon-125, Xenon-123, Iodine-125 and Iodine-123 in a process that includes irradiating a fertile metal material then using a one-step chemical procedure to collect a first mixture of about equal amounts of Radon-211 and Xenon-125, and a separate second mixture of about equal amounts of Iodine-123 and Astatine-211.

Mirzadeh, Saed (East Setauket, NY); Lambrecht, Richard M. (Quogue, NY)

1987-01-01

452

Method for gettering organic, inorganic and elemental iodine in aqueous solutions  

DOEpatents

A process for the removal of iodine from aqueous solutions, particularly the trapping of radioactive iodine to mitigate damage resulting from accidents or spills associated with nuclear reactors, by exposing the solution to well dispersed silver carbonate which reacts with the iodine and iodides, thereby gettering iodine and iodine compounds from solution. The iodine is not only removed from solution but also from the contiguous vapor.

Beahm, Edward C. (Oak Ridge, TN); Shockley, William E. (Oak Ridge, TN)

1990-01-01

453

Development of safe infrared gas lasers  

NASA Astrophysics Data System (ADS)

Infrared gas lasers find application in numerous civil and military areas. Such lasers are therefore being developed at different institutions around the world. However, the development of chemical infrared gas lasers such as chemical oxygen iodine lasers (COIL) involves the use of several hazardous chemicals. In order to exploit full potential of these lasers, one must take diligent care of the safety issues associated with the handling of these chemicals and the involved processes. The present paper discusses the safety aspects to be taken into account in the development of these infrared gas lasers including various detection sensors working in conjunction with a customized data acquisition system loaded with safety interlocks for safe operation. The developed safety schemes may also be implemented for CO2 gas dynamic laser (GDL) and hydrogen fluoride-deuterium fluoride (HF-DF) Laser.

Mainuddin; Singhal, Gaurav; Tyagi, R. K.; Maini, A. K.

2013-04-01

454

Controlled iodine release from polyurethane sponges for water decontamination.  

PubMed

Iodinated polyurethane (IPU) sponges were prepared by immersing sponges in aqueous/organic solutions of iodine or exposing sponges to iodine vapors. Iodine was readily adsorbed into the polymers up to 100% (w/w). The adsorption of iodine on the surface was characterized by XPS and SEM analyses. The iodine loaded IPU sponges were coated with ethylene vinyl acetate (EVA), in order to release iodine in a controlled rate for water decontamination combined with active carbon cartridge, which adsorbs the iodine residues after the microbial inactivation. The EVA coated IPU were incorporated in a water purifier and tested for iodine release to water and for microbial inactivation efficiency according to WQA certification program against P231/EPA for 250l, using 25l a day with flow rate of 6-8min/1l. The antimicrobial activity was also studied against Escherichia coli and MS2 phage. Bacterial results exceeded the minimal requirement for bacterial removal of 6log reduction throughout the entire lifespan. At any testing point, no bacteria was detected in the outlet achieving more than 7.1 to more than 8log reduction as calculated upon the inlet concentration. Virus surrogate, MS2, reduction results varied from 4.11log reduction under tap water, and 5.11log reduction under basic water (pH9) to 1.32 for acidic water (pH5). Controlled and stable iodine release was observed with the EVA coated IPU sponges and was effective in deactivating the bacteria and virus present in the contaminated water and thus, these iodinated PU systems could be used in water purification to provide safe drinking water. These sponges may find applications as disinfectants in medicine. PMID:24096017

Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Harik, Oshrat; Kunduru, Konda Reddy; Domb, Abraham J

2013-12-28

455

Determination of iodine to compliment mass spectrometric measurements  

SciTech Connect

The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples.

Hohorst, F.A.

1994-11-01

456

REVIEW: Iodine Determination by Inductively Coupled Plasma Spectrometry  

Microsoft Academic Search

Iodine is a chemical element with critical physiological roles and its determination using instrumental analysis is not trivial. Inductively coupled plasma spectrometry associated with either optical emission (ICP-OES) or mass spectrometry (ICP-MS) may be employed, but each alternative presents limitations considering iodine behavior in argon plasma and the occurrence of interferences. Sample preparation is also a critical issue when using

Adriana A. Oliveira; Lilian C. Trevizan; Joaquim A. Nóbrega

2010-01-01

457

Iodine-131 monitoring in sewage plant outflow.  

PubMed

Three different hospital sites (Oxford, Sutton and Guildford) have performed sampling of their local sewage plant outflow to determine levels of radioactivity resulting from iodine-131 patients undergoing radionuclide therapies. It was found that a maximum of 20% of activity discharged from the hospitals was present in the sewage plant final effluent channel. This is significantly below the level predicted by mathematical models in current use. The results further show that abatement systems to reduce public exposure are unlikely to be warranted at hospital sites. PMID:24270089

McGowan, D R; Pratt, B E; Hinton, P J; Peet, D J; Crawley, M T

2014-03-01

458

Advanced water iodinating system. [for potable water aboard manned spacecraft  

NASA Technical Reports Server (NTRS)

Potable water stores aboard manned spacecraft must remain sterile. Suitable sterilization techniques are needed to prevent microbial growth. The development of an advanced water iodinating system for possible application to the shuttle orbiter and other advanced spacecraft, is considered. The AWIS provides a means of automatically dispensing iodine and controlling iodination levels in potable water stores. In a recirculation mode test, simulating application of the AWIS to a water management system of a long term six man capacity space mission, noniodinated feed water flowing at 32.2 cu cm min was iodinated to 5 + or - ppm concentrations after it was mixed with previously iodinated water recirculating through a potable water storage tank. Also, the AWIS was used to successfully demonstrate its capability to maintain potable water at a de