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Sample records for solar-pumped iodine laser

  1. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, K. S.

    1985-01-01

    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.

  2. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, K. S.

    1986-01-01

    During this period the parametric studies of the iodine laser oscillator pumped by a Vortek simulator were carried out before amplifier studies. The amplifier studies are postponed to the extended period after completing 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) a 10 W CW iodine laser pumped by a Vortek solar simulator; (2) kinetic modeling to predict the time to lasing threshold, lasing time, and energy output of solar-pumped iodine laser; and (3) the study of the dye laser amplifier pumped by a Tamarack solar simulator.

  3. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  4. Solar-pumped photodissociation iodine laser

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Weaver, W. R.; Humes, D. H.; Williams, M. D.; Lee, M. H.

    1986-01-01

    The scientific feasibility of a solar-pumped iodine photodissociation laser for space applications is under investigation. Recently, a 2-W CW output for more than one hour was achieved using n-C3F7I vapor as the laser material and a vortex-stabilized argon arc as the light source.

  5. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Hwang, In Heon

    1990-01-01

    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.

  6. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  7. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.

    1987-01-01

    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.

  8. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    A XeCl laser pumped iodine laser oscillator was developed which will be incorporated into the Master Oscillator Power Amplifier (MOPA) system. The developed XeCl laser produces output energy of about 60 mJ per pulse. The pulse duration was about 10 nsec. The kinetic model for the solar-pumped laser was refined and the algorithm for the calculation of a set of rate equations was improved to increase the accuracy and the efficiency of the calculation. The improved algorithm was applied to explain the existing experimental data taken from a flashlamp pumped iodine laser for three kinds of lasants, i-C3F7I, n-C4F9I, and t-C4F9I. Various solid laser materials were evaluated for solar-pumping. The materials studied were Nd:YAG, Nd:YLF, and Cr:Nd:GSGG crystals. The slope efficiency of 0.17 percent was measured for the Nd:YLF near the threshold pump intensity which was 211 solar constants (29W/sq cm). The threshold pump intensity of the Nd:YAG was measured to be 236 solar constants (32W/sq cm) and the near-threshold slope efficiency was 0.12 percent. True CW laser operation of Cr:Nd:GSGG was possible only at pump intensities less than or equal to 1,500 solar constants (203 W/sq cm). This fact was attributed to the high thermal focusing effect of the Cr:Nd:GSGG rod.

  9. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1986-01-01

    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.

  10. Direct solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  11. Amplified spontaneous emission in solar-pumped iodine laser

    NASA Technical Reports Server (NTRS)

    Cho, Yong S.; Hwang, In H.; Han, Kwang S.; Lee, Ja H.

    1992-01-01

    The amplified spontaneous emission (ASE) from a long pulse, solar-simulating radiation pumped iodine laser amplifier is studied. The ASE threshold pump intensity is almost proportional to the inverse of the laser gain length when the gas pressure is constant in the laser tube.

  12. A long-pulse amplifier for solar-pumped iodine lasers

    NASA Technical Reports Server (NTRS)

    Hwang, I. H.; Lee, J. H.; Lee, M. H.

    1986-01-01

    The characteristics of a photodissociation iodine-laser amplifier pumped with a solar-simulating radiation were studied. Under long-pulse energy extraction, an energy amplification of about three and an energy storage time of longer than 500 microseconds were observed for a one meter long, 10 mm i.d. amplifier tube. The effects of elevated temperatures resulted in little reduction of the amplifier gain. These results confirm that developing an efficient chain of oscillator-amplifiers for a high-power solar-pumped iodine laser is indeed feasible.

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

    NASA Technical Reports Server (NTRS)

    Shiner, Christopher S.

    1986-01-01

    Research is directed toward the design and synthesis of new media for solar-pumped I* lasers. Since the most effective existing lasants are perfluoroalkyl iodides, a strategy was proposed for the development of improved materials of this type with absorption maxima at 300 nm. Absorption spectra were synthesized and measured for prototypical species containing iodine bound to boron, iron, and cobalt.

  14. Directly solar-pumped iodine laser for beamed power transmission in space

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    A new approach for development of a 50-kW directly solar-pumped iodine laser (DSPIL) system as a space-based power station was made using a confocal unstable resonator (CUR). The CUR-based DSPIL has advantages, such as performance enhancement, reduction of total mass, and simplicity which alleviates the complexities inherent in the previous system, master oscillator/power amplifier (MOPA) configurations. In this design, a single CUR-based DSPIL with 50-kW output power was defined and compared to the MOPA-based DSPIL. Integration of multiple modules for power requirements more than 50-kW is physically and structurally a sound approach as compared to building a single large system. An integrated system of multiple modules can respond to various mission power requirements by combining and aiming the coherent beams at the user's receiver.

  15. A 50-kW module power station of directly solar-pumped iodine laser

    SciTech Connect

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

    1997-11-01

    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 (>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.

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

  17. Solar pumped laser

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  18. Perfluorobutyl iodides as gain media for a solar-pumped iodine laser amplifier

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher M.; Lee, Min H.; Lee, Ja H.; Weaver, Willard R.

    1987-01-01

    The effectiveness of t-C4F9I and n-C4F9I as gain media for a space-based solar-pumped iodine photodissociation laser is investigated experimentally. The optically coupled flashlamp/amplifier-tube apparatus described by Hwang et al. (1986) is employed, driving the amplifier with 4-microsec 4.2-mJ TEM(00) pulses from a flashlamp-pumped laser oscillator; the variation of amplification with energy-extraction time was monitored by inserting a delay of up to 1 msec between the firing of the two flashlamps and measuring the delay between the optical pulses. The results are presented graphically and briefly characterized. The performance of t-C4F9I is found to be better than that of n-C4F9I (or n-C3F7I), with an absorption band shifted toward the visible (for improved utilization of solar radiation), higher gain (by a factor of 2) at all delay times, and better chemical reversibility. The gain did not depend significantly on temperature in any of the iodides.

  19. High-power, continuously solar pumped and Q-switched iodine laser

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Humes, D. H.; Weaver, W. R.; Tabibi, B. M.

    1988-10-01

    A train of high power (up to 160 W) Q-switched pulses at up to 1 kHz were continuously produced from a CW solar-simulator pumped iodine laser system. The Q-switching was accomplished by a fast mechanical chopper in the laser cavity and is the first reported Q-switching of a CW iodine laser. The dependence of CW and Q-switched laser powers on parameters such as the iodide vapor pressure, the flow rate, and the chopper speed are discussed.

  20. Direct solar-pumped iodine laser amplifier. Semiannual progress report, 1 March-31 August 1988

    SciTech Connect

    Han, K.S.; Hwang, I.H.; Stock, L.V.

    1988-10-01

    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.

  1. Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher M.; Lee, Ja H.

    1991-01-01

    A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement.

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

    NASA Technical Reports Server (NTRS)

    Shiner, C. S.

    1986-01-01

    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.

  3. Solar-pumped laser for free space power transmission

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1989-01-01

    Laser power transmission; laser systems; space-borne and available lasers; 2-D and 1 MW laser diode array systems; technical issues; iodine solar pumped laser system; and laser power transmission applications are presented. This presentation is represented by viewgraphs only.

  4. Advanced solar energy conversion. [solar pumped gas lasers

    NASA Technical Reports Server (NTRS)

    Lee, J. H.

    1981-01-01

    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.

  5. Solar Pumped Laser Microthruster

    SciTech Connect

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

    2010-10-08

    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.

  6. SOLAR PUMPED LASER MICROTHRUSTER

    SciTech Connect

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

    2010-02-05

    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.

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

    NASA Technical Reports Server (NTRS)

    Shiner, C. S.

    1985-01-01

    This work is directed toward the design and chemical synthesis of new media for solar-pumped I* lasers. In view of the desirability of preparing a perfluoroalkyl iodide absorbing strongly at 300 nm, the relationship betwen perfluoroalkyl iodide structure and the corresponding absorption wavelength was reexamined. Analysis of existing data suggests that, in this family of compounds, the absorption maximum shifts to longer wavelength, as desired, as the C-I bond in the lasant is progressively weakened. Weakening of the C-I bond correlates, in turn, with increasing stability of the perfluoroalkyl radical formed upon photodissociation of the iodide. The extremely promising absorption characteristics of perfluoro-tert-butyl iodide can be accounted for on this basis. A new technique of diode laser probing to obtain precise yields of I* atoms in photodissociation was also developed.

  8. Solar-pumped solid-state lasers

    SciTech Connect

    Weksler, M.; Shwartz, J.

    1988-06-01

    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 simple solar-pumped laser model, which is also presented. Using this model, it is shown that existing laser materials with broad-band absorption characteristics (e.g., alexandrite and Nd:Cr:GSGG) have a potential for better than 10 percent overall conversion efficiency when solar pumped.

  9. Solar-pumped gas laser development

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1981-01-01

    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.

  10. Feasibility of solar-pumped dye lasers

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    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.

  11. Solar Pumped Lasers and Their Applications

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1991-01-01

    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.

  12. Research on solar pumped liquid lasers

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  13. Research on solar pumped liquid lasers

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  14. Solar-pumped gas laser development

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.

    1980-01-01

    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.

  15. Scaling studies of solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Christiansen, W. H.; Chang, J.

    1985-01-01

    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.

  16. 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)

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

    1987-01-01

    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.

  17. Theoretical studies of solar pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, Wynford L.

    1990-01-01

    One concept for collecting solar energy is to use large solar collectors and then use lasers as energy converters whose output beams act as transmission lines to deliver the energy to a destination. The efficiency of the process would be improved if the conversion could be done directly using solar pumped lasers, and the possibility of making such lasers is studied. There are many applications for such lasers, and these are examined. By including the applications first, the requirements for the lasers will be more evident. They are especially applicable to the Space program, and include cases where no other methods of delivering power seem possible. Using the lasers for conveying information and surveillance is also discussed. Many difficulties confront the designer of an efficient system for power conversion. These involve the nature of the solar spectrum, the method of absorbing the energy, the transfer of power into laser beams, and finally, the far field patterns of the beams. The requirements of the lasers are discussed. Specific laser configurations are discussed. The thrust is into gas laser systems, because for space applications, the laser could be large, and also the medium would be uniform and not subject to thermal stresses. Dye and solid lasers are treated briefly. For gas lasers, a chart of the various possibilities is shown, and the various families of gas lasers divided according to the mechanisms of absorbing solar radiation and of lasing. Several specific models are analyzed and evaluated. Overall conclusions for the program are summarized, and the performances of the lasers related to the requirements of various applications.

  18. Key techniques for space-based solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    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.

  19. Model of a pulsed liquid solar-pumped spaceborne laser

    SciTech Connect

    Seregin, A A; Seregina, E A

    2004-02-28

    A model of a pulsed liquid solar-pumped laser is constructed. A neodymium-containing phosphorus oxychloride (POCl{sub 3}-SnCl{sub 4}-Nd{sup 3+}) liquid is proposed as an active medium. The lasing parameters of this medium are calculated for a spaceborne laser as functions of its size and the coefficient of solar energy concentration. (lasers)

  20. Efficiency of continuous-wave solar pumped semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Johnson, Stanley; Küppers, Franko; Pau, Stanley

    2013-04-01

    We report the results of an efficient solar pumped semiconductor laser system that uses high efficiency multi-junction photovoltaic cells and laser diodes in order to achieve the sunlight to laser light conversion efficiency of over 10% without any active cooling and concentration optics. Semiconductor lasers with wavelength from 445 nm to 1550 nm are powered directly by an array of photovoltaic (PV) cells under one sun illumination (100 mW/cm2). The maximum energy efficiency reaches 10.34% at 976 nm with an output power of 4.31 W. This system is inherently more efficient than direct solar pumped lasers that have been studied in the past and could play a key role in future renewable energy production and power beaming applications.

  1. Theoretical studies of solar-pumped lasers

    NASA Astrophysics Data System (ADS)

    Harries, W. L.

    1983-01-01

    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.

  2. Solar-pumped solid state Nd lasers

    NASA Technical Reports Server (NTRS)

    Williams, M. D.; Zapata, L.

    1985-01-01

    Solid state neodymium lasers are considered candidates for space-based polar-pumped laser for continuous power transmission. Laser performance for three different slab laser configurations has been computed to show the excellent power capability of such systems if heat problems can be solved. Ideas involving geometries and materials are offered as potential solutions to the heat problem.

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  4. Theoretical studies of solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1983-01-01

    Metallic vapor lasers of Na2 and Li2 are examined as solar energy converters. The absorbed photons cause transitions to vibrational-rotational levels in an upper electronic state. With broad band absorption the resultant levels can have quantum numbers considerably higher than the upper lasing level. The excited molecule then relaxes to the upper lasing level which is one of the lower vibrational levels in the upper electronic state. The relaxation occurs from collisions, provided the molecule is not quenched into the ground level electronic state. Lasing occurs with a transition to a vibrational level in the lower electronic state. Rough estimates of solar power efficiencies are 1 percent for Na2 and probably a similar figure for Li2. The nondissociative lasers from a family distinct from materials which dissociate to yield an excited atom.

  5. Solar Pumped Nd:Cr:GSGG Laser

    NASA Astrophysics Data System (ADS)

    Noter, Yoram; Oron, Moshe; Shwartz, Josef; Weksler, Meyer; Yogev, Amnon

    1989-07-01

    Direct solar illumination was used to pump a 1/4" x 3" Nd:Cr:GSGG rod and achieved quasi CW laser action at average powers of 20 watt. The solar radiation was chopped at a duty cycle of 20% to avoid crystal fracture. Peak power outputs were as high as 100 watt on a clear day. Slope efficiencies, relative to the solar power reaching the crystal, were close to 10%. Near field and far field beam patterns were recorded by a TV system in order to study the thermal behavior of the crystal. At maximum irradiation levels, the output from a 25 cm long flat concave cavity, had a beam divergence on the order of 30 mrad. Details of the experimental system and the calibration procedures are given.

  6. Concepts for efficient high power solar pumped solid state lasers

    NASA Astrophysics Data System (ADS)

    Opower, H.; Lindner, F.; Zittel, W.

    1988-01-01

    The energetic efficiencies obtainable with current solid state laser systems are examined and used in a theoretical study of a combined solar-pumped laser power plant. It is suggested that the incident light in such a system would be split into two parts. In one part the wavelength would be adjusted to the absorption spectra of the special laser crystals. This part would serve as the laser source. The other part of the light would deliver its energy to a solar dynamic and/or photovoltaic converter. The maximum yield that could be obtained from this type of system is estimated for ruby, Ti sapphire, Nd:YAG, and Nd-Cr-GSGG lasers.

  7. Solar Pumped High Power Solid State Laser for Space Applications

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

    2004-01-01

    Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

  8. Solar-pumped electronic-to-vibrational energy transfer lasers

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Wilson, J. W.

    1981-01-01

    The possibility of using solar-pumped lasers as solar energy converters is examined. The absorbing media considered are halogens or halogen compounds, which are dissociated to yield excited atoms, which then hand over energy to a molecular lasing medium. Estimates of the temperature effects for a Br2-CO2-He system with He as the cooling gas are given. High temperatures can cause the lower energy levels of the CO2 laser transition to be filled. The inverted populations are calculated and lasing should be possible. However, the efficiency is less than 0.001. Examination of other halogen-molecular lasant combinations (where the rate coefficients are known) indicate efficiencies in all cases of less than 0.005.

  9. Highly efficient solar-pumped Nd:YAG laser.

    PubMed

    Liang, Dawei; Almeida, Joana

    2011-12-19

    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

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

    SciTech Connect

    Hwang, I.H. . Dept. of Physics); Lee, J.H. . Langley Research Center)

    1991-09-01

    This paper reports on the efficiencies and threshold pump intensities of various solid-state laser materials that have been estimated to compare their performance characteristics as direct solar-pumped CW lasers. Among the laser materials evaluated in this research, alexandrite has the highest slope efficiency of about 12.6%; however, it does not seem to be practical for 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 (AMO) solar constants and its slope efficiency is about 12% when thermal deformation is completely prevented.

  11. Laser emission from a solar-pumped fiber.

    PubMed

    Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Suzuki, Takenobu; Ohishi, Yasutake

    2012-03-12

    We report the realization of a solar-pumped fiber laser (SPFL) using a double-clad (a center core/ an inner clad working also as optical waveguide/ an outer clad) Nd-doped fluoride optical fiber as a laser medium. With a compact off-axis parabolic mirror of 5 cm in aperture diameter, the natural sunlight is concentrated by a factor 10?, and introduced partly into the core of the fiber and partly into the inner clad in which the light is guided in some distance and transferred to the core after all. We have obtained clear laser spectrum characteristics with approximately 0.01 nm full-width-half-maximum of the laser line at the peak wavelength of 1053.7 nm, a low-lasing threshold of 49.1 mW, a slope efficiency of 6.6%, and a total efficiency of 1.76%. Further optimization of the medium properties, optical cavity, and concentration technique will yield higher efficiency and lower threshold. PMID:22418466

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

    NASA Technical Reports Server (NTRS)

    Hwang, In H.; Lee, Ja H.

    1991-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

    Ogawa, Takayo; Wada, Satoshi; Higuchi, Mikio

    2014-02-01

    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.

  14. Threshold of stimulated Brillouin scattering by use of a solar pumped laser.

    PubMed

    Naftali, Nir; Benmair, Ruth M J; Pe'er, Idit; Yogev, Ammon

    2002-06-20

    What is to our knowledge the first stimulated Brillouin scattering experiment using a high-power low-gain solar pumped laser is presented. A threshold reflectivity of 0.23% was reached when a peak power of 20.7 kW was used at 7.6 GHz. A cw solar pumped laser was Q-switched with an acousto-optic modulator, and the bandwidth was narrowed with an intracavity etalon. A high polarization ratio (>99.4%) was achieved by use of an intracavity configuration. Higher reflectivity values were limited because of the lack of availability of optical switches. PMID:12078683

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

    NASA Astrophysics Data System (ADS)

    Ogawa, Takayo; Wada, Satoshi; Higuchi, Mikio

    2014-08-01

    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 m 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.

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Williams, M. D.

    1984-01-01

    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.

  18. Threshold pump power of a solar-pumped dye laser

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    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.

  19. Kinetic modeling of an IBr solar pumped laser

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Meador, W. E.

    1983-01-01

    The possibility of using an IBr laser as a solar-energy converter is examined theoretically, and reasons for its choice are given. Broadband absorption results in dissociation with the formation of excited metastable Br atoms, some of which then lase to the ground state Br. The ground state is depopulated by three-body recombination and, more importantly, by exchange reactions which more than compensate for the high quenching in heteronuclear halogen systems. Kinetic modeling indicates lasing is possible in the pulsed mode and possibly in the steady state with a cooled gas flow system. Temperature effects are discussed. The efficiency of the laser approaches 1.2 percent at optical thicknesses large enough for complete absorption of the photons.

  20. Solar-Pumped TEM₀₀ Mode Nd:YAG laser.

    PubMed

    Liang, Dawei; Almeida, Joana

    2013-10-21

    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 TEM₀₀ (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

  1. Thermal analysis in a solar pumped laser for Mg energy cycle

    NASA Astrophysics Data System (ADS)

    Bagheri, Behgol; Uchidat, Shgeaki

    2012-10-01

    Thermal analysis of a high-power cw solar-pumped laser under development as a magnesium energy cycle driver has been conducted experimentally and analytically. The laser system is equipped with a Fresnel lens and a cone-shaped secondary mirror chamber (SMC). The SMC realizes a hybrid-pumping scheme combining axial- and side-pumping configurations to enhance solar light absorption to a rod-shaped laser medium. A non-uniform temperature profile was obtained during experiments due to combination of volumetric heating and surface cooling, which leads to a nonuniform variation of index of refraction in the laser medium. The thermal lensing and thermal stress-induced birefringence are analyzed.

  2. A path to practical Solar Pumped Lasers via Radiative Energy Transfer

    NASA Astrophysics Data System (ADS)

    Reusswig, Philip D.; Nechayev, Sergey; Scherer, Jennifer M.; Hwang, Gyu Weon; Bawendi, Moungi G.; Baldo, Marc. A.; Rotschild, Carmel

    2015-10-01

    The optical conversion of incoherent solar radiation into a bright, coherent laser beam enables the application of nonlinear optics to solar energy conversion and storage. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-μm-thick Nd3+-doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CW solar lasing threshold of 23 W-cm-2, or approximately 230 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns.

  3. A path to practical Solar Pumped Lasers via Radiative Energy Transfer

    PubMed Central

    Reusswig, Philip D.; Nechayev, Sergey; Scherer, Jennifer M.; Hwang, Gyu Weon; Bawendi, Moungi G.; Baldo, Marc. A.; Rotschild, Carmel

    2015-01-01

    The optical conversion of incoherent solar radiation into a bright, coherent laser beam enables the application of nonlinear optics to solar energy conversion and storage. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-μm-thick Nd3+-doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CW solar lasing threshold of 23 W-cm−2, or approximately 230 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns. PMID:26434400

  4. A path to practical Solar Pumped Lasers via Radiative Energy Transfer

    SciTech Connect

    Reusswig, Philip D.; Nechayev, Sergey; Scherer, Jennifer M.; Hwang, Gyu Weon; Bawendi, Moungi G.; Baldo, Marc. A.; Rotschild, Carmel

    2015-10-05

    The optical conversion of incoherent solar radiation into a bright, coherent laser beam enables the application of nonlinear optics to solar energy conversion and storage. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-μm-thick Nd 3+ -doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CW solar lasing threshold of 23 W-cm-2, or approximately 230 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns.

  5. A path to practical Solar Pumped Lasers via Radiative Energy Transfer

    DOE PAGESBeta

    Reusswig, Philip D.; Nechayev, Sergey; Scherer, Jennifer M.; Hwang, Gyu Weon; Bawendi, Moungi G.; Baldo, Marc. A.; Rotschild, Carmel

    2015-10-05

    The optical conversion of incoherent solar radiation into a bright, coherent laser beam enables the application of nonlinear optics to solar energy conversion and storage. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-μm-thick Nd 3+ -doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CWmore » solar lasing threshold of 23 W-cm-2, or approximately 230 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns.« less

  6. A path to practical Solar Pumped Lasers via Radiative Energy Transfer.

    PubMed

    Reusswig, Philip D; Nechayev, Sergey; Scherer, Jennifer M; Hwang, Gyu Weon; Bawendi, Moungi G; Baldo, Marc A; Rotschild, Carmel

    2015-01-01

    The optical conversion of incoherent solar radiation into a bright, coherent laser beam enables the application of nonlinear optics to solar energy conversion and storage. Here, we present an architecture for solar pumped lasers that uses a luminescent solar concentrator to decouple the conventional trade-off between solar absorption efficiency and the mode volume of the optical gain material. We report a 750-μm-thick Nd(3+)-doped YAG planar waveguide sensitized by a luminescent CdSe/CdZnS (core/shell) colloidal nanocrystal, yielding a peak cascade energy transfer of 14%, a broad spectral response in the visible portion of the solar spectrum, and an equivalent quasi-CW solar lasing threshold of 23 W-cm(-2), or approximately 230 suns. The efficient coupling of incoherent, spectrally broad sunlight in small gain volumes should allow the generation of coherent laser light from intensities of less than 100 suns. PMID:26434400

  7. Solar Pumped Solid State Lasers for Space Solar Power: Experimental Path

    NASA Technical Reports Server (NTRS)

    Fork, Richard L.; Carrington, Connie K.; Walker, Wesley W.; Cole, Spencer T.; Green, Jason J. A.; Laycock, Rustin L.

    2003-01-01

    We outline an experimentally based strategy designed to lead to solar pumped solid state laser oscillators useful for space solar power. Our method involves solar pumping a novel solid state gain element specifically designed to provide efficient conversion of sunlight in space to coherent laser light. Kilowatt and higher average power is sought from each gain element. Multiple such modular gain elements can be used to accumulate total average power of interest for power beaming in space, e.g., 100 kilowatts and more. Where desirable the high average power can also be produced as a train of pulses having high peak power (e.g., greater than 10(exp 10 watts). The modular nature of the basic gain element supports an experimental strategy in which the core technology can be validated by experiments on a single gain element. We propose to do this experimental validation both in terrestrial locations and also on a smaller scale in space. We describe a terrestrial experiment that includes diagnostics and the option of locating the laser beam path in vacuum environment. We describe a space based experiment designed to be compatible with the Japanese Experimental Module (JEM) on the International Space Station (ISS). We anticipate the gain elements will be based on low temperature (approx. 100 degrees Kelvin) operation of high thermal conductivity (k approx. 100 W/cm-K) diamond and sapphire (k approx. 4 W/cm-K). The basic gain element will be formed by sequences of thin alternating layers of diamond and Ti:sapphire with special attention given to the material interfaces. We anticipate this strategy will lead to a particularly simple, robust, and easily maintained low mass modelocked multi-element laser oscillator useful for space solar power.

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Kurweg, U. H.

    1984-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Monson, D. J.

    1978-01-01

    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).

  11. Consideration of coordinated solar tracking of an array of compact solar-pumped lasers combined with photovoltaic cells for electricity generation

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

    A monochromatic laser light with a photon energy just above the band edge of photovoltaic cells can be converted into electricity with minimal thermal loss. To attain efficient conversion of sunlight to laser light, a coordinated solar tracking system for an array of originally designed compact solar-pumped lasers of 50 mm aperture diameter is being constructed. As for the feasibility of this system, a prototype with a holding capacity of 25 compact solar-pumped lasers has been fabricated. The primary requisite of this system is that the angular accuracy of tracking should be below 1 mrad for all 25 compact solar-pumped lasers to sustain their continuous lasing. To realize this, imperative challenges have been elucidated including thermal expansion under sunlight. A prototype fabricated with its main frame made of Super Invar alloy was found to fulfill the requisite by measurement using a three-dimensional coordinate measuring machine.

  12. A model for the kinetics of a solar-pumped long path laser experiment

    NASA Technical Reports Server (NTRS)

    Stock, L. V.; Wilson, J. W.; Deyoung, R. J.

    1986-01-01

    A kinetic model for a solar-simulator pumped iodine laser system is developed and compared to an experiment in which the solar simulator output is dispersed over a large active volume (150 cu cm) with low simulator light intensity (approx. 200 solar constants). A trace foreign gas which quenches the upper level is introduced into the model. Furthermore, a constant representing optical absorption of the stimulated emission is introduced, in addition to a constant representing the scattering at each of the mirrors, via the optical cavity time constant. The non-uniform heating of the gas is treated as well as the pressure change as a function of time within the cavity. With these new phenomena introduced into the kinetic model, a best reasonable fit to the experimental data is found by adjusting the reaction rate coefficients within the range of known uncertainty by numerical methods giving a new bound within this range of uncertainty. The experimental parameters modeled are the lasing time, laser pulse energy, and time to laser threshold.

  13. Preliminary design and cost of a 1-megawatt solar-pumped iodide laser space-to-space transmission station

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    A preliminary conceptual design of a space-based solar pumped iodide laser emitting 1 megawatt of laser power for space-to-space power transmission is described. A near parabolic solar collector focuses sunlight onto the t-C4F9I (perfluoro-t butyl iodide) lasant within a transverse flow optical cavity. Using waste heat, a thermal system was designed to supply compressor and auxiliary power. System components were designed with weight and cost estimates assigned. Although cost is very approximate, the cost comparison of individual system components leads to valuable insights for future research. In particular, it was found that laser efficiency was not a dominant cost or weight factor, the dominant factor being the laser cavity and laser transmission optics. The manufacturing cost was approx. two thirds of the total cost with transportation to orbit the remainder. The flowing nonrenewable lasant comprised 20% of the total life cycle cost of the system and thus was not a major cost factor. The station mass was 92,000 kg without lasant, requiring approx. four shuttle flights to low Earth orbit where an orbital transfer vehicle will transport it to the final altitude of 6378 km.

  14. Preliminary design and cost of a 1-megawatt solar-pumped iodide laser space-to-space transmission station

    NASA Astrophysics Data System (ADS)

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

    1987-09-01

    A preliminary conceptual design of a space-based solar pumped iodide laser emitting 1 megawatt of laser power for space-to-space power transmission is described. A near parabolic solar collector focuses sunlight onto the t-C4F9I (perfluoro-t butyl iodide) lasant within a transverse flow optical cavity. Using waste heat, a thermal system was designed to supply compressor and auxiliary power. System components were designed with weight and cost estimates assigned. Although cost is very approximate, the cost comparison of individual system components leads to valuable insights for future research. In particular, it was found that laser efficiency was not a dominant cost or weight factor, the dominant factor being the laser cavity and laser transmission optics. The manufacturing cost was approx. two thirds of the total cost with transportation to orbit the remainder. The flowing nonrenewable lasant comprised 20% of the total life cycle cost of the system and thus was not a major cost factor. The station mass was 92,000 kg without lasant, requiring approx. four shuttle flights to low Earth orbit where an orbital transfer vehicle will transport it to the final altitude of 6378 km.

  15. Scalable chemical oxygen - iodine laser

    SciTech Connect

    Adamenkov, A A; Bakshin, V V; Vyskubenko, B A; Efremov, V I; Il'in, S P; Ilyushin, Yurii N; Kolobyanin, Yu V; Kudryashov, E A; Troshkin, M V

    2011-12-31

    The problem of scaling chemical oxygen - iodine lasers (COILs) is discussed. The results of experimental study of a twisted-aerosol singlet oxygen generator meeting the COIL scalability requirements are presented. The energy characteristics of a supersonic COIL with singlet oxygen and iodine mixing in parallel flows are also experimentally studied. The output power of {approx}7.5 kW, corresponding to a specific power of 230 W cm{sup -2}, is achieved. The maximum chemical efficiency of the COIL is {approx}30%.

  16. Threshold kinetic processes for t-C4F9I. [for solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Lee, J. H.; Wilson, J. W.; Humes, D. H.; Weaver, W. R.; Enderson, T.; Tabibi, B. M.

    1985-01-01

    To determine the relative threshold of the lasant gas t-C4F9I in comparison to n-C3F7I, the pump energy to reach threshold for photodissociation iodine lasing is measured in a common aparatus. The comparison is made for the threshold energies in the iodide pressure range up to 50 Torr when 64-J electric input into a flashlamp is used for pumping. It is shown from the results that qualitative differences between the thresholds of the two gases result from the degree to which steady state is achieved by the time threshold is reached. The estimated recombination rate for t-C4F9I is found to be much larger than the value given by Ershov et al (1978).

  17. Perfluoro-n-hexyl iodide as gain media for high power, continuous solar-pumped lasers

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Tabibi, Bagher M.; Humes, Donald H.; Weaver, Willard R.

    1990-01-01

    A comparative study of CW laser performance with n-C6F13I and n-C3F7I was performed using a 10-W solar-simulator-pumped laser system. The measured output power for n-C6F13I is near 10 W and is comparable to that of n-C3F7I. However, n-C6F13I has the advantages of easy purification and repeated use.

  18. An all-gas-phase amine based iodine laser using molecular iodine as atomic iodine donor

    NASA Astrophysics Data System (ADS)

    Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

    2010-01-01

    The laser action of an all-gas-phase iodine laser that 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( 2P 3/2) atoms. The replacement of iodine source from HI to I 2 had been desired, but it was considered to be difficult due to the high deactivation reaction rate of excited iodine atoms by residual I 2. In this system, iodine atoms are produced by microwave discharge. Continuous-wave laser output of 35 mW with a duty factor of 40% was observed. This is 70% of the output from the same system with HI iodine source.

  19. Development of a chemical oxygen - iodine laser with production of atomic iodine in a chemical reaction

    SciTech Connect

    Censky, M; Spalek, O; Jirasek, V; Kodymova, J; Jakubec, I

    2009-11-30

    The alternative method of atomic iodine generation for a chemical oxygen - iodine laser (COIL) in chemical reactions with gaseous reactants is investigated experimentally. The influence of the configuration of iodine atom injection into the laser cavity on the efficiency of the atomic iodine generation and small-signal gain is studied. (lasers)

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

    NASA Astrophysics Data System (ADS)

    Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

    2010-10-01

    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.

  1. Overview of iodine generation for oxygen-iodine lasers

    NASA Astrophysics Data System (ADS)

    Jirsek, Vt.

    2012-01-01

    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.

  2. Transverse flow CW atomic iodine laser system

    SciTech Connect

    Schlie, L. A.; Rathge, R. D.

    1985-08-13

    A transverse flow CW atomic iodine laser system uses a closed cycle fuel system to operate in a continuous mode. An elliptical pump cell having a Hg arc lamp cooled by deionized water irradiates with UV energy C/sub 3/F/sub 7/I gas to produce excited atomic iodine. A transverse flow section attached to the pump cell channels C/sub 3/F/sub 7/I gas into a laser cell where lasing occurs. The flow section has upstream and downstream flow cavities, triangular shaped, that channel the laser gas. A diffuser and flow straighteners are placed in these cavities to make the flow velocity across the transverse laser axis as uniform as possible so as to produce very stable laser gain output.

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

    NASA Astrophysics Data System (ADS)

    Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

    2010-09-01

    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.

  4. 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)

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

    2015-01-01

    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.

  5. Overview of repetitively pulsed photolytic iodine lasers

    NASA Astrophysics Data System (ADS)

    Schlie, L. A. V.

    1996-02-01

    The performance of a repetitively pulsed, 70 joule, closed cycle 1.3 (mu) M photolytic atomic iodine laser with excellent beam quality (BQ equals 1.15) is presented. This BQ was exhibited in the fundamental mode from a M equals 3.1 confocal unstable resonator at a 0.5 Hz repetition rate. A closed cycle scrubber/laser fuel system consisting of a condensative- evaporative section, two Cu wool I2 reactor regions, and an internal turbo-blower enabled the laser to operate very reliably with low maintenance. The fuel system provided C3F7I gas at 10 - 60 torr absent of the photolytic quenching by-product I2. Using a turbo- molecular blower longitudinal flow velocities greater than 10 m/s were achieved through the 150 cm long by 7.5 multiplied by 7.5 cm2 cross sectional photolytic iodine gain region. In addition to the high laser output and excellent BQ, the resulting 8 - 12 microsecond laser pulse had a coherence length greater than 45 meters and polarization extinction ratio better than 100:1. Projections from this pulsed photolytic atomic iodine laser technology to larger energies, higher repetition rates, and variable pulse widths are discussed.

  6. A model for a continuous-wave iodine laser

    NASA Technical Reports Server (NTRS)

    Hwang, In H.; Tabibi, Bagher M.

    1990-01-01

    A model for a continuous-wave (CW) iodine laser has been developed and compared with the experimental results obtained from a solar-simulator-pumped CW iodine laser. The agreement between the calculated laser power output and the experimental results is generally good for various laser parameters even when the model includes only prominent rate coefficients. The flow velocity dependence of the output power shows that the CW iodine laser cannot be achieved with a flow velocity below 1 m/s for the present solar-simulator-pumped CW iodine laser system.

  7. A model for a continuous-wave iodine laser

    SciTech Connect

    Hwang, I.H.; Tabibi, B.M. Spaceborne Photonics Institute, Hampton University,Hampton, VA )

    1990-11-15

    A model for a continuous-wave (CW) iodine laser has been developed and compared with the experimental results obtained from a solar-simulator-pumped CW iodine laser. The agreement between the calculated laser power output and the experimental results is generally good for various laser parameters even when the model includes only prominent rate coefficients. The flow velocity dependence of the output power shows that the CW iodine laser cannot be achieved with a flow velocity below 1 m/s for the present solar-simulator-pumped CW iodine laser system.

  8. Laser Induced Fluorescence of the Iodine Ion

    NASA Astrophysics Data System (ADS)

    Hargus, William

    2014-10-01

    Iodine (I2) has been considered as a potential electrostatic spacecraft thruster propellant for approximately 2 decades, but has only recently been demonstrated. Energy conversion efficiency appears to be on par with xenon without thruster modification. Intriguingly, performance appears to exceed xenon at high acceleration potentials. As part of a continuing program for the development of non-intrusive plasma diagnostics for advanced plasma spacecraft propulsion, we have identified the I II 5d5D4 o state as metastable, and therefore containing a reservoir of excited state ions suitable for laser probing. The 5d5D4 o - 6p5P3 transition at 695.878 nm is convenient for diode laser excitation with the 5s5S2 o - 6p5P3 transition at 516.12 nm as an ideal candidate for non-resonant fluorescence collection. We have constructed a Penning type iodine microwave discharge lamp optimized for I II production for table-top measurements. This work demonstrates I II laser-induced fluorescence in a representative iodine discharge and will validate our previous theoretical work based on the limited available historical I II spectral data.

  9. Magnetic Q-switching of a photolytic iodine laser

    SciTech Connect

    Highland, R.; Dunkle, E.; Hanko, L.; Hager, G.

    1988-01-01

    The Zeeman effect has been utilized in a switching technique for an atomic iodine laser. This effect is used here to demonstrate a gas phase, self-healing Q-switch for a small (1 mW) CW photolytic iodine laser. Enhancement ratios of pulse power over CW power on the order of 55 to 1 were achieved. 20 references.

  10. Satellite Power System (SPS) laser studies. Volume 2: Meteorological effects on laser beam propagation and direct solar pumped lasers for the SPS

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The primary emphasis of this research activity was to investigate the effect of the environment on laser power transmission/reception from space to ground. Potential mitigation techniques to minimize the environment effect by a judicious choice of laser operating parameters was investigated. Using these techniques, the availability of power at selected sites was determined using statistical meteorological data for each site.

  11. Repetitively pulsed q-switched chemical oxygen-iodine laser

    SciTech Connect

    Hager, G.D.

    1985-10-07

    This invention overcomes the problems of severe flux-induced density gradients in a continuous-wave subsonic cavity of a chemical oxygen-iodine laser by operating the laser in a repetitively pulsed mode through the incorporation therein of a scaleable intracavity gas-phase Q-switch. This abstract discloses a repetitively cavity containing a lasing medium in the form of a flowing mixture of excited oxygen and iodine atoms and an iodine absorption region within the resonant cavity. The iodine absorption region includes a source of iodine atoms and a magnetic field associated therewith. Selectively altering the magnetic field results in changing the absorption characteristics of the iodine atoms and, therefore, effectively pulses the output of the laser.

  12. Solar-simulator-pumped atomic iodine laser kinetics

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  13. Space interferometry application of laser frequency stabilization with molecular iodine.

    PubMed

    Leonhardt, Volker; Camp, Jordan B

    2006-06-10

    A number of planned space interferometry missions, including the Laser Interferometer Space Antenna (LISA) gravitational wave detector, require a laser system with high-frequency stability over long time scales. A 1064 nm wavelength nonplanar ring oscillator (NPRO) laser stabilized to a resonant transition in molecular iodine is suitable for these missions, providing high-frequency stability at an absolute reference frequency. The iodine stabilized laser also offers low sensitivity to temperature and alignment fluctuations and allows frequency tuning. We have evaluated the noise performance of a NPRO laser stabilized to iodine using frequency modulation spectroscopy and have found an Allan standard deviation of 10(-14) over 100 s. Simplified optical configurations and the radiation hardness of the frequency-doubling crystals have also been investigated. PMID:16761057

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

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    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.

  15. Investigation of the excited state iodine lifetime in the photodissociation of perfluoroalkyl iodides

    NASA Technical Reports Server (NTRS)

    Cobb, Stephen H.

    1991-01-01

    An evaluation of prospective laser materials for a space-based solar pumped laser system over the past decade has resulted in the identification of the iodine photodissociation laser as that system best suited to solar-pumped high energy operation. The active medium for the solar-pumped iodine photodissociation laser is from the family of perfluoroalkyl iodides. These lasants have the general form C(n)F(2n + 1)I, often abbreviated as RI. These iodides are known to exhibit photodissociaiton of the C-I bond when irradiated by near UV photons. The focus was on the experimental determination of the lifetime of the excited iodine atom following photodissociation of C4F9I, and also to monitor fluorescence from the iodine molecule at 500 nm to determine if I2 is being produced in the process. Photodissociation is achieved using an XeCl excimer laser with an output wavelength of 308 nm. The XeCl beam is focused into the middle of a cylindrical quartz cell containing the lasant. The laser pulse is detected with a fast risetime photomultiplier tube as it exits the cell. Other aspects of the investigation are discussed.

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

    SciTech Connect

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

    2009-01-31

    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 CH{sub 3}I is used as the donor of atomic iodine. The fraction of iodine extracted from CH{sub 3}I in the generator is {approx}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 {approx}3%. (elements of laser setups)

  17. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.; Lee, Ja H.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by a XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodine pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  18. Enhanced performance of an electric oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    Experiments and modeling have led to continued enhancements in 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. A 95% enhancement in cw laser power was achieved via a 50% increase in gain length, flow rates, and discharge power. A further 87% increase in extracted laser power was obtained using a larger mode volume resonator. The gain has improved by more than 100-fold from the initial demonstration of 0.002% cm-1 to 0.26% cm-1, and similarly the outcoupled laser power has improved more than 500-fold from 0.16 W to 102 W.

  19. Studies of new media radiation induced laser

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  20. Discharge formation systems for generating atomic iodine in a pulse-periodic oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Aksinin, V. I.; Antsiferov, S. A.; Velikanov, S. D.; Gerasimov, A. Yu; Gostev, I. V.; Kazantsev, S. Yu; Kalinovskii, V. V.; Konovalov, V. V.; Kononov, I. G.; Mikhalkin, V. N.; Podlesnykh, S. V.; Sevryugin, I. V.; Firsov, K. N.

    2014-01-01

    Generation characteristics of a pulse-periodic oxygen-iodine laser with the electro-discharge production of atomic iodine were compared with inductively stabilised edged or anisotropic- resistive cathodes used for ignition of the volume discharge. The discharge was initiated by the radiation of a barrier discharge from the side of a grid anode. It was found that at equal specific electrical energy depositions to the gas-discharge plasma, the system with the anisotropic-resistive cathode provides a more stable and uniform volume discharge with the possibility of varying the composition and pressure of working mixtures over a wide range and a greater specific extraction of laser energy is observed (up to 2.4 J L-1). At a high pulse repetition rate of laser pulses (50 - 100 Hz) and long duration of the pulse trains (longer than a minute) the surface of anisotropic-resistive cathode became eroded.

  1. Recent electric oxygen-iodine laser experiments and modeling

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    Experiments and modeling have led to a continuing evolution of the Electric Oxygen-Iodine Laser (ElectricOIL) system. A new concentric discharge geometry has led to improvements in O2(a) production and efficiency and permits higher pressure operation of the discharge at high flow rate. A new heat exchanger design reduces the O2(a) loss and thereby increases the O2(a) delivered into the gain region for a negligible change in flow temperature. These changes have led to an increase in laser cavity gain from 0.26% cm-1 to 0.30% cm-1. New modeling with BLAZE-V shows that an iodine pre-dissociator can have a dramatic impact upon gain and laser performance. As understanding of the ElectricOIL system continues to improve, the design of the laser systematically evolves.

  2. Molecular Iodine Fluorescence Using a Green Helium-Neon Laser

    ERIC Educational Resources Information Center

    Williamson, J. Charles

    2011-01-01

    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

  3. Molecular Iodine Fluorescence Using a Green Helium-Neon Laser

    ERIC Educational Resources Information Center

    Williamson, J. Charles

    2011-01-01

    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…

  4. Iodine photodissociation laser with an intracavity space - time light modulator

    SciTech Connect

    Kachalin, G N; Pevny, S N; Pivkin, A N; Safronov, A S

    2012-08-31

    A scheme of an iodine laser with two different intracavity space - time modulators based on electrooptic PLZT ceramics is experimentally studied. It is shown that lasing can occur in different angular directions with the use of both modulators. The output laser energy is 10 mJ with a pulse duration of 200 {mu}s and a beam divergence of 6.3 Multiplication-Sign 10{sup -4} rad. The laser field of view (5.1 Multiplication-Sign 10{sup -3} rad) consists of a discrete set of 8 Multiplication-Sign 8 directions. (control of laser radiation parameters)

  5. Production of iodine atoms for an oxygen-iodine laser from iodine-containing molecules with the help of atomic oxygen

    SciTech Connect

    Shepelenko, A A; Mikheev, P A

    2003-03-31

    A new technique is proposed for the production of atomic iodine for a cw oxygen-iodine laser with the use of reactions between iodine donor molecules and oxygen atoms. The CH{sub 3}I, CF{sub 3}I, or I{sub 2} molecules can be used as donors. Oxygen atoms are injected into the reaction region by admixing the flow of partially dissociated oxygen produced in an electric discharge. The use of atomic iodine instead of molecular iodine excludes the consumption of singlet oxygen O{sub 2}({sup 1{Delta}}) for the dissociation of I{sub 2} and quenching of I* by the I{sub 2} molecules. The latter will supposedly allow raising the optimal density of I and accordingly the gain coefficient. Estimates were made of the required degree of dissociation of oxygen employed to obtain iodine atoms at which the above advantages can be realised. (lasers)

  6. Chemical oxygen iodine laser (COIL) technology and development

    NASA Astrophysics Data System (ADS)

    Duff, Edward A.; Truesdell, Keith A.

    2004-09-01

    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.

  7. Energy transfer efficiency from Cr(3+) to Nd(3+) in solar-pumped laser using transparent Nd/Cr:Y(3)Al(5)O(12) ceramics.

    PubMed

    Hasegawa, Kazuo; Ichikawa, Tadashi; Mizuno, Shintaro; Takeda, Yasuhiko; Ito, Hiroshi; Ikesue, Akio; Motohiro, Tomoyoshi; Yamaga, Mitsuo

    2015-06-01

    We report energy transfer efficiency from Cr3+ to Nd3+ in Nd (1.0 at.%)/Cr (0.4 at.%) co-doped Y3Al5O12 (YAG) transparent ceramics in the laser oscillation states. The laser oscillation has performed using two pumping lasers operating at 808 nm and 561 nm; the former pumps Nd3+ directly to create the 1064 nm laser oscillation, whereas the latter assists the performance via Cr3+ absorption and sequential energy transfer to Nd3+. From the laser output power properties and laser mode analysis, the energy transfer efficiency was determined to be around 65%, which is close to that obtained from the spontaneous Nd3+ emission. PMID:26072876

  8. Evolution of the electric discharge oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    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, size scaling is presently showing a super-linear growth in performance; a 95% enhancement in cw laser power was achieved via a 50% increase in gain length, flow rates, and discharge power. New gain recovery measurements and modeling downstream of an operating laser cavity are presented in this work for a wider range of flow conditions to help identify previously unidentified kinetic processes. Larger volume resonators that extend further downstream in the flow direction were able to extract more of the excess energy being carried by the O2(a) from the ElectricOIL gain medium; a further 87% increase in extracted laser power was obtained. As understanding of the ElectricOIL system continues to improve, the design of the laser systematically evolves. The gain has improved by more than 100-fold from the initial demonstration of 0.002% cm-1 to 0.26% cm-1, and similarly the outcoupled laser power has increased more than 600-fold from 0.16 W to 109 W.

  9. XeCl laser pumped iodine laser using t-C4F9I

    NASA Technical Reports Server (NTRS)

    Hwang, In Heon; Han, Kwang S.

    1989-01-01

    An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used.

  10. Nuclear-driven flashlamp pumping of the atomic iodine laser

    NASA Astrophysics Data System (ADS)

    Miley, G. H.

    1992-03-01

    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 B-10 and He-3, 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 percent. 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 percent) 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 C3F7I, 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.

  11. Nuclear-driven flashlamp pumping of the atomic iodine laser

    SciTech Connect

    Miley, G.H.

    1992-03-01

    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.

  12. Iodine

    MedlinePLUS

    ... 6 weeks increases the healing rate. Also, applying povidone-iodine in addition to compression seems help heal ... Catheter-related infection. Some evidence suggests that applying povidone-iodine reduces the risk of blood stream infections ...

  13. Iodine

    MedlinePLUS

    ... 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 to get enough iodine for their babies ...

  14. Discharge formation systems for generating atomic iodine in a pulse-periodic oxygen–iodine laser

    SciTech Connect

    Aksinin, V I; Kazantsev, S Yu; Kononov, I G; Podlesnykh, S V; Firsov, K N; Antsiferov, S A; Velikanov, S D; Gerasimov, A Yu; Gostev, I V; Kalinovskii, V V; Konovalov, V V; Mikhalkin, V N; Sevryugin, I V

    2014-01-31

    Generation characteristics of a pulse-periodic oxygen–iodine laser with the electro-discharge production of atomic iodine were compared with inductively stabilised edged or anisotropic- resistive cathodes used for ignition of the volume discharge. The discharge was initiated by the radiation of a barrier discharge from the side of a grid anode. It was found that at equal specific electrical energy depositions to the gas-discharge plasma, the system with the anisotropic-resistive cathode provides a more stable and uniform volume discharge with the possibility of varying the composition and pressure of working mixtures over a wide range and a greater specific extraction of laser energy is observed (up to 2.4 J L{sup -1}). At a high pulse repetition rate of laser pulses (50 – 100 Hz) and long duration of the pulse trains (longer than a minute) the surface of anisotropic-resistive cathode became eroded. (laser applications and other topics in quantum electronics)

  15. Iodine

    USGS Publications Warehouse

    Krukowski, S.T.

    2006-01-01

    In descending order, Chile, Japan and the United States have the largest iodine reserves. Chile produces iodine from iodate minerals while Japan and the United States produce it from sodium iodide solutions found in underground iodide solutions. Iodine is also produced from subterranean brines in Azerbaijan, Russia, Turkmenista, Indonesia and Uzbekistan. In 2005, iodine prices increased sharply to US$19 to US$23 then leveled off at US$23 to US$25.

  16. Excited states in the active media of oxygen - iodine lasers

    SciTech Connect

    Azyazov, V N

    2009-11-30

    A review of investigations of kinetic processes in active media oxygen - iodine lasers (OILs) performed in the last decade is presented. The mechanisms of pumping and quenching of electronically and vibrationally excited O{sub 2} and I{sub 2} molecules are considered, and dissociation mechanisms of I{sub 2} in the active medium of the OIL are analysed. The values of kinetic constants of processes proceeding in the active media of OILs are recommended. (review)

  17. Super-linear enhancement of the electric oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

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

    2012-01-01

    Continuing experiments with Electric Oxygen-Iodine Laser (EOIL) technology have significantly increased laser power output by increasing the product of gain and gain-length, g0L. Increasing the system size by a factor of 3 resulted in a 5-fold increase in laser output on the 1315-nm transition of atomic iodine. The peak output power observed was 538 W.

  18. Development of the electric discharge oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    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

    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.

  19. Applications of the chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Latham, W. Pete; Kendrick, Kip R.; Quillen, Brian

    2000-01-01

    The Chemical Oxygen-Iodine Laser (COIL) has been developed at the Air Force Research Laboratory for military applications. For example, the COIL is to be use as the laser device for the ABL. A high power laser is useful for applications that require the delivery of a substantial amount of energy to a very small focused laser spot. The COIL is a member of the class of high power lasers that are also useful for industrial applications, including the materials processing task of high speed cutting and drilling. COIL technology has received considerable interest over the last several years due to its short, fiber- deliverable wavelength, scalability to very high powers, and demonstrated nearly diffraction-limited optical quality. These unique abilities make it an ideal candidate for nuclear reactor decommissioning and nuclear warhead dismantlement. Japanese researchers envision using a COIL for disaster cleanup and survivor rescue. It is also being studied by the oil and gas industry for well drilling. Any commercial or industrial application that requires very rapid, precise, and noninvasive cutting or drilling, could be readily accomplished with a COIL. Because of the substantial power levels available with a COIL, the laser could also be used for broad area applications such as paint stripping. This paper includes a collection of experiments accomplished at the Air Force Research Laboratory Chemical Laser Facility, including metal cutting, hole drilling, high power fiber optic transmission, and rock crushing.

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

    SciTech Connect

    Vagin, Nikolai P; Yuryshev, Nikolai N

    2002-07-31

    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. (lasers)

  1. New singlet oxygen generator for chemical oxygen-iodine lasers

    NASA Astrophysics Data System (ADS)

    Yoshida, S.; Saito, H.; Fujioka, T.; Yamakoshi, H.; Uchiyama, T.

    1986-11-01

    Experiments have been carried out to investigate a new method for generating O2(1Delta) with long-time operation of an efficient chemical oxygen-iodine laser system in mind. An impinging-jet nozzle was utilized to atomize a H2O2-KOH solution so that the alkaline H2O2/Cl2 reaction might occur in droplet-gas phase with high excitation efficiency. Experimental results indicate that the present generator can yield as high as 80 percent of O2(1Delta) with reasonable O2 flow rate.

  2. Fluorescence of iodine-127 and iodine-129 isotopes excited by radiation of copper vapor lasers (578.2 nm): I. Fluorescence of 127I2

    NASA Astrophysics Data System (ADS)

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

    2013-07-01

    This two-part paper reports the results of the first theoretical and experimental studies of the fluorescence of molecular iodine-127 and iodine-129 isotopes excited by copper vapor laser radiation (578.2 nm). This first part deals with the study of iodine-127 fluorescence. Excited transitions were identified, and obtained fluorescence spectra were investigated in detail.

  3. Fluorescence of iodine-127 and iodine-129 isotopes excited by radiation of copper vapor laser (510.6?nm)

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.; Simanovsky, I. G.; Suganeev, S. V.

    2014-07-01

    The paper deals with the study of 127I2, 127I129I and 129I2 fluorescence excited by radiation of a copper vapor laser at 510.6?nm. Iodine molecule absorption lines, resonant at the wavelength of laser radiation, were identified. The obtained results were compared to those obtained while exciting fluorescence with lasers radiating at wavelengths 578.2 and 532?nm. It was shown that copper vapor lasers with a wavelength of 510.6 are promising for performing high-sensitive real-time detection of molecular iodine-129 in gaseous media. The obtained results may be used for developing totally new cost-effective and environmentally friendly technologies of electricity generation, based on fast reactors, which is extremely important for providing humanity with environmentally friendly generated electric energy.

  4. Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Abbitt, John D., III; Mcdaniel, James C.

    1989-01-01

    A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions.

  5. Power laser beaming and applications in space

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.; Conway, Edmund J.

    1991-01-01

    The concept of power-laser beaming in space is described with reference to particular technologies for such systems and their potential applications. A power-beaming system comprises a laser transmitter and receiver, beam-directing optics, and a laser-to-electric power converter, and the system can be used to: (1) extend a lunar rover's excursion range; (2) boost power levels onboard the Space Station Freedom; and (3) to realize laser propulsion. Attention is also given to the potential pump power available from the strongest solar-pumped iodine photodissociation lasers which, when used with a t-C4F9I lasant, is a suitable laser power transmitter.

  6. Threshold kinetics of a solar-simulator-pumped iodine laser

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Lee, Y.; Weaver, W. R.; Humes, D. H.; Lee, J. H.

    1984-01-01

    A model of the chemical kinetics of the n-C3F7I solar-simulator-pumped iodine laser is utilized to study the major kinetic processes associated with the threshold behavior of this experimental system. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state diffusion to the cell wall is the dominant limiting factor below 5 torr. Excited-state recombination with the alkyl radical and quenching by the parent gas control threshold at higher pressures. Treatment of the hyperfine splitting and uncertainty in the pressure broadening are important factors in fixing the threshold level. In spite of scatter in the experimental data caused by instabilities in the simulator high-pressure high-pressure arc, reasonable agreement is achieved between the model and experiment. Model parameters arrived at are within the uncertainty range of values found in the literature.

  7. Investigation of laser-induced iodine fluorescence for the measurement of density in compressible flows

    NASA Technical Reports Server (NTRS)

    Mcdaniel, J. C., Jr.

    1982-01-01

    Laser induced fluorescence is an attractive nonintrusive approach for measuring molecular number density in compressible flows although this technique does not produce a signal that is directly related to the number density. Saturation and frequency detuned excitation are explored as means for minimizing the quenching effect using iodine as the molecular system because of its convenient absorption spectrum. Saturation experiments indicate that with available continuous wave laser sources of Gaussian transverse intensity distribution only partial saturation could be achieved in iodine at the pressures of interest in gas dynamics. Using a fluorescence lineshape theory, it is shown that for sufficiently large detuning of a narrow bandwidth laser from a molecular transition, the quenching can be cancelled by collisional broadening over a large range of pressures and temperatures. Experimental data obtained in a Mach 4.3 underexpanded jet of nitrogen seeded with iodine for various single mode argon laser detunings from a strong iodine transition at 5145 A are discussed.

  8. Gain and temperature in a slit nozzle supersonic chemical oxygen-iodine laser with transonic and supersonic injection of iodine

    NASA Astrophysics Data System (ADS)

    Rosenwaks, Salman; Barmashenko, Boris D.; Bruins, Esther; Furman, Dov; Rybalkin, Victor; Katz, Arje

    2002-05-01

    Spatial distributions of the gain and temperament across the flow were studied for transonic and supersonic schemes of the iodine injection in a slit nozzle supersonic chemical oxygen-iodine laser as a function of the iodine and secondary nitrogen flow rate, jet penetration parameter and gas pumping rate. The mixing efficiency for supersonic injection of iodine is found to be much larger than for transonic injection, the maximum values of the gain being approximately 0.65 percent/cm for both injection schemes. Measurements of the gain distribution as a function of the iodine molar flow rate nI2 were carried out. For transonic injection the optimal value of nI2 at the flow centerline is smaller than that at the off axis location. The temperature is distributed homogeneously across the flow, increasing only in the narrow boundary layers near the walls. Opening a leak downstream of the cavity in order to decease the Mach number results in a decrease of the gain and increase of the temperature. The mixing efficiency in this case is much larger than for closed leak.

  9. LASERS: Iodine laser pumped by light from a shock front created by detonating an explosive

    NASA Astrophysics Data System (ADS)

    Arzhanov, V. P.; Borovich, Boris L.; Zuev, V. S.; Kazanski?, V. M.; Katulin, V. A.; Kirillov, G. A.; Kormer, S. B.; Kuratov, Yu V.; Kuryapin, A. I.; Nosach, O. Yu; Sinitsyn, M. V.; Sto?lov, Yu Yu

    1992-02-01

    The results are presented of investigations, performed in 1965-1966, of a pulsed photodissociation iodine laser utilizing CF3I and C3F7I molecules and pumped by light from a shock front created by detonating an explosive charge. Such lasers were found to possess a unique combination of high output energy and high pulse power. Two types of laser were studied. In one of them the active medium was pumped by light from a shock wave in xenon, and in the other a shock wave propagated through a mixture of the active medium and a rare gas. The energy characteristics of the second type of laser were found to be considerably higher than those of the first type. The laser pulse radiation enegy reached ~100 J with an average power of ~15 MW.

  10. Discharge-driven electric oxygen-iodine laser superlinear enhancement via increasing g0L.

    PubMed

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

    2012-05-01

    The authors report the development of an electric oxygen-iodine laser with higher output using a larger product of gain and gain length, g0L. A factor of 4.4 increase in laser power output on the 1315 nm atomic iodine transition was achieved with a factor of 3 increase in gain length. I(2P1/2) is pumped using energy transferred from O2(a1?) produced by flowing a gas mixture of O2-He-NO through three coaxial geometry radio-frequency discharges. Continuous wave (CW) average total laser power of 481 W was extracted with g0L=0.042. PMID:22555687

  11. Injectant mole-fraction imaging in compressible mixing flows using planar laser-induced iodine fluorescence.

    PubMed

    Hartfield, R J; Abbitt Iii, J D; McDaniel, J C

    1989-08-15

    A technique is described for imaging the injectant mole-fraction distribution in nonreacting compressible mixing flow fields. Planar fluorescence from iodine, seeded into air, is induced by a broadband argon-ion laser and collected using an intensified charge-injection-device array camera. The technique eliminates the thermodynamic dependence of the iodine fluorescence in the compressible flow field by taking the ratio of two images collected with identical thermodynamic flow conditions but different iodine seeding conditions. The resulting images are, to our knowledge, the first quantitative planar measurements of mole-fraction distributions in a nonreacting compressible flow field and allow mixing to be studied directly. PMID:19752989

  12. A 10-watt CW photodissociation laser with IODO perfluoro-tert-butane

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher; Venable, Demetrius D.

    1989-01-01

    NASA has been investigating the feasibility of direct solar-pumped laser systems for power beaming in space. Among the various gas, liquid, and solid laser systems being proposed as candidates for solar-pumped lasers, the iodine photodissociation gas laser has demonstrated its potential for space application. Of immediate attention is the determination of system requirements and the choice of lasants to improve the system efficiency. The development of an efficient iodine laser depends on the availability of a suitable iodide which has favorable laser kinetics, chemically reversibility, and solar energy utilization. Among the various alkyliodide lasants comparatively tested in a long-pulse system, perfluoro- tert-butyl iodide, T-C4F9I, was found to be the best. However, the operating conditions for the laser medium in a continuously pumped and continuous-flow iodine laser differ considerably from those in the pulsed regime. The results of the continuous wave (CW)) laser performance from t-C4F9I are reported. Perfluoro- n-propyl iodide, n-C3F7I is used for comparison because of its universal use in photodissociation iodine lasers.

  13. Lasers '91; Proceedings of the 14th International Conference on Lasers and Applications, San Diego, CA, Dec. 9-13, 1991

    NASA Astrophysics Data System (ADS)

    Duarte, F. J.; Harris, D. G.

    The present conference discusses advances in SDIO laser research, X-ray laser photopumping, efficient X-ray lasers, line-selected operation of HF/DF lasers, Monte Carlo simulations of RF excited SF6 discharge, amplified spontaneous emission in solar-pumped iodine laser, efficient optical parametric converters for blue-green laser sources, novel narrowband filters, and sub-Poissonian lasers and masers. Also discussed are ultrafast light modulation by induced frequency shift, performance predictions for 3D lidar imaging systems, imaging techniques for pulse-Doppler lidar, spatial frequency mixing in photorefractive crystals, sideband generation with electrooptic modulators, a high energy density self-sustained CO2 laser, Nd:YAG laser welding of Al alloys, laser processes for integrating substrate fabrication, laser interactions with matter, resonators and propagation, solid-state lasers, Faraday filters, excimer lasers, far-IR lasers, laser spectroscopy, dye lasers, nuclear-pumped lasers, and lasers in medicine.

  14. High-power iodine laser application for remote D and D cutting

    NASA Astrophysics Data System (ADS)

    Vetrovec, John; Hindy, Robert N.; Subbaraman, Ganesan; Spiegel, Lyle P.

    1997-04-01

    This paper discusses the use of high-power lasers to remotely process material for decommissioning and dismantlement of nuclear facilities. Process requirements are established and suitable laser systems are compared. The chemical oxygen- iodine laser was identified as the leading candidate for long term dismantlement activities because it offers a high-power, high-brightness beam that can be remotely delivered into radiation containment by optical fibers.

  15. Planar temperature measurement in compressible flows using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    A laser-induced iodine fluorescence technique that is suitable for the planar measurement of temperature in cold nonreacting compressible air flows is investigated analytically and demonstrated in a known flow field. The technique is based on the temperature dependence of the broadband fluorescence from iodine excited by the 514-nm line of an argon-ion laser. Temperatures ranging from 165 to 245 K were measured in the calibration flow field. This technique makes complete, spatially resolved surveys of temperature practical in highly three-dimensional, low-temperature compressible flows.

  16. Determination of iodine in oyster tissue by isotope dilution laser resonance ionization mass spectrometry

    SciTech Connect

    Fassett, J.D.; Murphy, T.J. )

    1990-02-15

    The technique of laser resonance ionization mass spectrometry has been combined with isotope dilution analysis to determine iodine in oyster tissue. The long-lived radioisotope, 129I, was used to spike the samples. Samples were equilibrated with the 129I, wet ashed under controlled conditions, and iodine separated by coprecipitation with silver chloride. The analyte was dried as silver ammonium iodide upon a tantalum filament from which iodine was thermally desorbed in the resonance ionization mass spectrometry instrument. A single-color, two-photon resonant plus one-photon ionization scheme was used to form positive iodine ions. Long-lived iodine signals were achieved from 100 ng of iodine. The precision of 127I/129I measurement has been evaluated by replicate determinations of the spike, the spike calibration samples, and the oyster tissue samples and was 1.0%. Measurement precision among samples was 1.9% for the spike calibration and 1.4% for the oyster tissue. The concentration of iodine determined in SRM 1566a, Oyster Tissue, was 4.44 micrograms/g with an estimate of the overall uncertainty for the analysis of +/- 0.12 microgram/g.

  17. Self-initiating volume discharge in iodides used for producing atomic iodine in pulsed chemical oxygen - iodine lasers

    SciTech Connect

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

    2003-06-30

    A volume self-sustained discharge (VSD) in iodides (C{sub 3}H{sub 7}I, C{sub 4}H{sub 9}I) and in their mixtures with SF{sub 6}, N{sub 2}, and O{sub 2} 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 SF{sub 6} or N{sub 2} to the iodides improves the stability and homogeneity of the SIVD, while adding up to 300 % (relative to the partial iodide pressure) of O{sub 2} 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 C{sub 4}H{sub 9}I:O{sub 2}:SF{sub 6}=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{sup -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. (lasers)

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

    SciTech Connect

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

    2013-04-15

    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.

  19. Repetitively pulsed, 70-J photolytic iodine laser with excellent optical and long-reliable operation

    NASA Astrophysics Data System (ADS)

    Schlie, L. A.; Rathge, R. D.

    1995-06-01

    The performance of a repetitively pulsed, 70 joule, closed cycle 1.3 mu M photolytic atomic iodine laser with excellent beam quality (BQ = 1.15) is presented. This BQ was exhibited in the fundamental mode from a M = 3.1 confocal unstable resonator at a 0.5 Hz repetition rate. A closed cycle scrubber/laser fuel system consisting of a condensative-evaporative section, two Cu wool I2 reactor regions, and an internal turbo-blower enabled the laser to operate very reliably with low maintenance. The fuel system provided C3F7I gas at 10-60 torr absent of the photolytic quenching by-product I2. Using a turbo-molecular blower longitudinal flow velocities greater than 10 m/s were achieved through the 150 cm long by 7.5 x 7.5 cm(exp 2) cross sectional photolytic iodine gain region. In addition to the high laser output and excellent BQ, the resulting 8-12 mu s laser pulse had a coherence length greater than 45 meters and polarization extinction ratio better than 100:1. Projections from this pulsed photolytic atomic iodine laser technology to larger energies, higher repetition rates, and variable pulse widths are discussed.

  20. Fluorescence of iodine-127 and iodine-129 isotopes excited by radiation of copper vapor lasers (578.2 nm): II. Fluorescence of 127I129I and 129I2

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    This paper reports on the results of research into the fluorescence of molecular iodine-127 and iodine-129 isotopologues, excited by copper vapor lasers at a wavelength of 578.2 nm. It is shown that these lasers are a promising source for developing a high-sensitivity selective laser-fluorescence method for iodine isotopologue detection in gaseous media, in particular in the atmosphere.

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

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    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.

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

    SciTech Connect

    Vagin, Nikolai P; Yuryshev, Nikolai N

    2001-02-28

    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 {mu}s were obtained, which corresponds to a concentration of iodine atoms of 1.8 x 10{sup 15} cm{sup -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{sup -1} and a specific power of 75 kW litre{sup -1} were obtained. The ways of increasing these parameters were indicated. It was found that SF{sub 6} is an efficient buffer gas favouring improvements in the energy pulse parameters. (lasers)

  3. Singlet oxygen generator for a supersonic chemical oxygen iodine laser: parametric study and recovery of chemicals

    NASA Astrophysics Data System (ADS)

    Spalek, Otomar; Kodymova, Jarmila

    1997-04-01

    A jet singlet oxygen generator for a supersonic chemical oxygen-iodine laser was studied including singlet delta oxygen, O2(1(Delta) g), and residual chlorine concentration measurements. The investigation was intended mainly for a water vapor measurement in gas effluent of generator in dependence on properties of liquid jets: a chemical composition and temperature of the input liquid (alkaline solution of hydrogen peroxide), a liquid jets diameter and their geometrical arrangement. Effects of these parameters on output power of a small-scale supersonic laser were studied as well. Possible approaches to a chemical fuels management in a chemical oxygen-iodine laser for industrial applications are considered. An 'open loop' cycle with a possible use of sodium hydroxide, and a 'closed loop' cycle with a regeneration of both potassium hydroxide and hydrogen peroxide are discussed.

  4. An all gas-phase iodine laser based on amine chemistry

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

    Laser action has been demonstrated for the 2P1/2-2P3/2 transition of iodine atom pumped by energy transfer from NCl(a1?) 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 model calculations.

  5. Similarity criteria in calculations of the energy characteristics of a cw oxygen - iodine laser

    SciTech Connect

    Mezhenin, A V; Azyazov, V N

    2012-12-31

    The calculated and experimental data on the energy efficiency of a cw oxygen - iodine laser (OIL) are analysed based on two similarity criteria, namely, on the ratio of the residence time of the gas mixture in the resonator to the characteristic time of extraction of the energy stored in singlet oxygen td and on the gain-to-loss ratio {Pi}. It is shown that the simplified two-level laser model satisfactorily predicts the output characteristics of OILs with a stable resonator at {tau}{sub d} {<=} 7. Efficient energy extraction from the OIL active medium is achieved in the case of {tau}{sub d} = 5 - 7, {Pi} = 4 - 8. (lasers)

  6. Oxygen-iodine ejector laser with a centrifugal bubbling singlet-oxygen generator

    SciTech Connect

    Zagidullin, M V; Nikolaev, V D; Svistun, M I; Khvatov, N A

    2005-10-31

    It is shown that if a supersonic oxygen-iodine ejector laser is fed by singlet oxygen from a centrifugal bubbling generator operating at a centrifugal acceleration of {approx}400g, the laser output power achieves a value 1264 W at a chemical efficiency of 24.6% for an alkaline hydrogen peroxide flow rate of 208 cm{sup 3}s{sup -1} and a specific chlorine load of 1.34 mmol s{sup -1} per square centimetre of the bubble layer. (lasers)

  7. Frequency Locking of 543 nm He Ne Laser on Iodine Spectrum

    NASA Astrophysics Data System (ADS)

    Ishibashi, Toshiaki; Yamashita, Masafumi; Tako, Toshiharu; Li, Yong; Hatakeyama, Shigeo; Sakamoto, Katsuhira; Inaba, Hajime; Akimoto, Yoshiaki

    1994-03-01

    Frequency tuning of internal-mirror 543 nm He Ne lasers was realized using a piezo-electric transducer (PZT) through an elastic deformation of the laser tube. Two 543 nm He Ne lasers were locked on the saturated absorption lines of iodine with the third-derivative signal of a signal-to-noise ratio of about 50. From the beat signal between them the frequency stability was measured to be ?(?, 2)=1.210-11?-1/2(10-4 s

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

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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.

  9. Lasic -Cavity-enhanced molecular iodine laser frequency stabilization for space projects

    NASA Astrophysics Data System (ADS)

    Turazza, Oscar; Acef, O.; Auger, G.; Halloin, H.; Duburck, F.; Plagnol, E.; Holleville, D.; Dimarcq, N.; Binetruy, P.; Brillet, A.; Lemonde, P.; Devismes, E.; Prat, P.; Lours, M.; Tuckey, P.; Argence, B.

    We present work in progress at SYRTE, APC and ARTEMIS aiming at stabilizing the frequency of a Nd:YAG laser using saturated absorption spectroscopy of molecular iodine 127I2. The novel design of the LASIC project allows for robustness and compacity while achieving high-performance phase noise suppression. The project is a follow-up of the laser stabilization work started at Artemis and continued at APC. The use of a low-finesse bow-tie optical cavity around the iodine absorber, combined with an adapted high-frequency modulation of the laser phase -NICE-OHMS technique-yields shot-noise limited saturated absorption signals with cavity-enhanced signal-to-noise ratios. Residual fractional frequency instability in terms of Allan Std. Deviation is expected below 10-14 @1s integration time and down to 10-15 over several hours. The compact iodine / cavity design, and performance well above LISA requirements make this project an interesting candidate for the space-based Gravitational Waves detector. We discuss the scientific background and outline of this project within the LISA framework, as well as its potential impact on other stringent technical requirements of the LISA project (e.g. U.S.O. clock-stability, arm-length measurements. . . ). We also present other possible applications for space projects involving interferometry, laser ranging or onboard ultrastable oscillators.

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

    NASA Technical Reports Server (NTRS)

    Seasholtz, Richard G.; Buggele, Alvin E

    1997-01-01

    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.

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

    SciTech Connect

    Miley, G.H.

    1992-03-01

    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.

  12. Unstable resonators of high-power chemical oxygen-iodine lasers

    SciTech Connect

    Savin, A V; Strakhov, S Yu; Druzhinin, S L

    2006-09-30

    Configurations of unstable resonators are considered depending on the basic parameters of a high-power chemical oxygen-iodine laser and the design of an unstable resonator is proposed which provides the compensation of the inhomogeneity of the small-signal gain downstream of the active medium, a high energy efficiency, and stability to intracavity aberrations. The optical scheme of this resonator is presented and its properties are analysed by simulating numerically the kinetics of the active medium and resonator itself in the diffraction approximation. (laser beams and resonators)

  13. Enhancement of electric oxygen-iodine laser performance using larger mode volume resonators.

    PubMed

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

    2010-05-15

    Herein the authors report on the demonstration of an 87% enhancement in cw laser power on the 1315 nm transition of atomic iodine via a 100% increase in the resonator mode volume. O(2)(a1Delta) is produced by a single rf-excited electric discharge sustained in an O(2)-He-NO gas mixture flowing through a rectangular geometry, and I(P2(1/2)) is then pumped using energy transferred from O(2)(a1Delta). A total laser output power of 102.5 W was obtained using a Z-pass resonator configuration. PMID:20479825

  14. Compact iodine-stabilized laser operating at 531 nm with stability at the 10^-12 level and using a coin-sized laser module

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takumi; Akamatsu, Daisuke; Hosaka, Kazumoto; Inaba, Hajime; Okubo, Sho; Tanabe, Takehiko; Yasuda, Masami; Onae, Atsushi; Hong, Feng-Lei

    2015-08-01

    We demonstrate a compact iodine-stabilized laser operating at 531 nm using a coin-sized light source consisting of a 1062-nm distributed-feedback diode laser and a frequency-doubling element. A hyperfine transition of molecular iodine is observed using the light source with saturated absorption spectroscopy. The light source is frequency stabilized to the observed iodine transition and achieves frequency stability at the 10$^{-12}$ level. The absolute frequency of the compact laser stabilized to the $a_{1}$ hyperfine component of the $R(36)32-0$ transition is determined as $564\\,074\\,632\\,419(8)$ kHz with a relative uncertainty of $1.4\\times10^{-11}$. The iodine-stabilized laser can be used for various applications including interferometric measurements.

  15. Numerical simulation of an all gas-phase iodine laser based on NCl3 reaction system

    NASA Astrophysics Data System (ADS)

    Masuda, Taizo; Endo, Masamori; Uchiyama, Taro

    2008-03-01

    A numerical simulation code for an all gas-phase iodine laser based on the NCl3 reaction system is developed. The model is a one-dimensional, multiple-leaky-stream-tubes kinetics code combined with all the known rate equations to date. To confirm the validity of this simulation code, the calculated results are compared with the experimental results obtained in other laboratories. The results of computer calculations utilizing this model are in good agreement with those experimental results. This agreement shows that the code is capable of precisely predicting the small signal gain and laser output for a given set of flow conditions. Using this simulation code, we defined the flow rates and the nozzle configuration that should allow laser oscillation based on NCl3 reaction system to be achieved. The calculations suggest that a laser output power of 410 mW can be obtained under optimum conditions with facilities available in our laboratory.

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

    SciTech Connect

    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

    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)

  17. A unified planar measurement technique for compressible flows using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

    A unified laser-induced fluorescence technique for conducting planar measurements of temperature, pressure and velocity in nonreacting, highly compressible flows has been developed, validated and demonstrated. Planar fluorescence from iodine, seeded into air, was induced by an argon-ion laser and collected using a liquid-nitrogen cooled CCD camera. In the measurement technique, temperature is determined from the fluorescence induced with the laser operated broad band. Pressure and velocity are determined from the shape and position of the fluorescence excitation spectrum which is measured with the laser operated narrow band. The measurement approach described herein provides a means of obtaining accurate, spatially-complete maps of the primary flow field parameters in a wide variety of cold supersonic and transonic flows.

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

    NASA Astrophysics Data System (ADS)

    Gao, Zhi; Hu, Limin; Shen, Yiqing

    2004-05-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    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.

  1. Observation of iodine transitions using the second and third harmonics of a 1.5-μm laser

    NASA Astrophysics Data System (ADS)

    Klein, R.; Arie, A.

    2002-07-01

    This paper presents spectroscopic measurements of iodine at 778 nm and 518 nm performed by second and third harmonics of a 1.5-μm diode laser, generated by quasi-phase matching in a periodically poled lithium niobate waveguide. Sub-Doppler spectroscopy by a 780-nm source was also demonstrated, and shows the potential of the system to reach high levels of frequency stability by locking the laser to the iodine transitions. The suggested method significantly improves the number of frequency references available for stabilizing 1550-nm lasers.

  2. Analysis of the effect of anhydride of trifluoroacetanhydride in the working mixture composition on the operation of iodine photodissociation laser

    NASA Astrophysics Data System (ADS)

    Vinogradskii, L. M.; Polozov, A. A.; Khudikov, N. M.

    2015-12-01

    The effect of the (CF3CO)2O (trifluoroacetanhydride) buffer additive on the operation of an iodine photodissociation laser is studied experimentally. Comparative experiments for determining the laser energy of the iodine laser with the replacement of the working substance with this buffer additive and without it and with widely used buffer gas SF6 (sulfur hexafluoride) are carried out. Optical inhomogeneities in the working volume, emerging during pumping of working mixtures based on i-C3F7I (perfluoroalkyl iodide) with buffer additives (CF3CO)2O and C6F14 (perfluorohexane), are measured. The results of experiments are analyzed.

  3. Laser excited fluorescence of molecular iodine 127I and 129I isotopes in the 632-637 nm spectral region

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2011-10-01

    Experimental and theoretical studies of fluorescence of long-lived molecular iodine 127I and 129I isotopes excited by radiation emitted by frequency-tunable semiconductor laser were conducted for the first time. The results obtained demonstrate the potential of development of real-time laser detector of the isotopes in question.

  4. A pressure recovery system for chemical oxygen-iodine laser based on an active diffuser

    NASA Astrophysics Data System (ADS)

    Malkov, V. M.; Kiselev, I. A.; Orlov, A. E.; Shatalov, I. V.

    2011-09-01

    An open-type pressure recovery system (PRS) for chemical oxygen-iodine laser was designed and fabricated. As a first stage, an active diffuser was used in which the ejecting gas supply was organized through nozzles disposed around the channel periphery. The second stage was a supersonic ejector. Numerical simulation data for the viscous turbulent flow with heat release through the diffuser gas-dynamic channel, and also data obtained by testing the active diffuser in operation on a model facility equipped with a vacuum chamber, are reported. The obtained data were used to develop a full-scale setup with exhaust of laser gas into the atmosphere; this has allowed us to optimize the performance characteristics of the setup and substantially improve its mass-dimensional characteristics. Special attention was paid to parameter matching and synchronization of laser start with the operation of PRS components.

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

    NASA Astrophysics Data System (ADS)

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

    2006-07-01

    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.

  6. Quantitative characterization of a nonreacting, supersonic combustor flowfield using unified, laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Fletcher, D. G.; Mcdaniel, J. C.

    1989-01-01

    A calibrated, nonintrusive optical technique, laser-induced iodine fluorescence (LIIF) was used to quantify the steady, compressible flowfield of a nonreacting, supersonic combustor. The combustor was configured with single and staged, transverse-air injection into a supersonic-air freestream behind a rearward-facing step. Pressure, temperature, two-velocity components, and injectant mole fraction were measured with high spatial resolution in the three-dimensional flowfields. These experimental results provide a benchmark set of data for validation of computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields.

  7. Chemical oxygen-iodine laser (COIL) for the dismantlement of nuclear facilities

    NASA Astrophysics Data System (ADS)

    Hallada, Marc R.; Seiffert, Stephan L.; Walter, Robert F.; Vetrovec, John

    2000-05-01

    The dismantlement of obsolete nuclear facilities is a major challenge for both the US Department of Energy and nuclear power utilities. Recent demonstrations have shown that lasers can be highly effective for size reduction cutting, especially for the efficient storage and recycling of materials. However, the full benefits of lasers can only be realized with high average power beams that can be conveniently delivered, via fiber optics, to remote and/or confined areas. Industrial lasers that can meet these requirements are not available now or for the foreseeable future. However, a military weapon laser, a Chemical Oxygen Iodine Laser (COIL), which has been demonstrated at over a hundred kilo Watts, could be adapted to meet these needs and enable entirely new industrial applications. An 'industrialized' COIL would enable rapid sectioning of thick and complex structures, such as glove boxes, reactor vessels, and steam generators, accelerating dismantlement schedules and reducing worker hazards. The full advantages of lasers in dismantlement could finally be realized with a portable COIL which is integrated with sophisticated robotics. It could be built and deployed in less than two years, breaking the paradigm of labor-intensive dismantlement operations and cutting processing times and costs dramatically.

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

    NASA Astrophysics Data System (ADS)

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

    1993-06-01

    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 result of recombination of charged or neutral particles. The conductivity in doped films is possibly due to the flow of iodine anions in the external electric field. These charged particles arise in an unexcited state of the complex under the thermal influence of a laser pulse.

  9. Combining laser frequency combs and iodine cell calibration techniques for Doppler detection of exoplanets

    NASA Astrophysics Data System (ADS)

    Cahoy, Kerri; Fischer, Debra; Spronck, Julien; DeMille, David

    2010-07-01

    Exoplanets can be detected from a time series of stellar spectra by looking for small, periodic shifts in the absorption features that are consistent with Doppler shifts caused by the presence of an exoplanet, or multiple exoplanets, in the system. While hundreds of large exoplanets have already been discovered with the Doppler technique (also called radial velocity), our goal is to improve the measurement precision so that many Earth-like planets can be detected. The smaller mass and longer period of true Earth analogues require the ability to detect a reflex velocity of ~10 cm/s over long time periods. Currently, typical astronomical spectrographs calibrate using either Iodine absorptive cells or Thorium Argon lamps and achieve ~10 m/s precision, with the most stable spectrographs pushing down to ~2 m/s. High velocity precision is currently achieved at HARPS by controlling the thermal and pressure environment of the spectrograph. These environmental controls increase the cost of the spectrograph, and it is not feasible to simply retrofit existing spectrometers. We propose a fiber-fed high precision spectrograph design that combines the existing ~5000-6000 A Iodine calibration system with a high-precision Laser Frequency Comb (LFC) system from ~6000-7000 A that just meets the redward side of the Iodine lines. The scientific motivation for such a system includes: a 1000 A span in the red is currently achievable with LFC systems, combining the two calibration methods increases the wavelength range by a factor of two, and moving redward decreases the "noise" from starspots. The proposed LFC system design employs a fiber laser, tunable serial Fabry-Perot cavity filters to match the resolution of the LFC system to that of standard astronomical spectrographs, and terminal ultrasonic vibration of the multimode fiber for a stable point spread function.

  10. Demonstration of an iodine laser pumped by an air-helium electric discharge

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

    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 discharge, cold gas injection was employed to raise the gas density and lower the temperature of the continuous gas flow. Gain of 0.0062% cm-1 was obtained and the laser output power was 32 mW in a supersonic flow cavity.

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

    SciTech Connect

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

    2014-12-31

    We have determined the influence of the reaction of molecular singlet oxygen with a vibrationally excited ozone molecule O{sub 2}(a {sup 1}Δ) + O{sub 3}(ν) → 2O{sub 2} + O on the removal rate of O{sub 2}(a {sup 1}Δ) in an electric-discharge-driven oxygen – iodine laser. This reaction has been shown to be a major channel of O{sub 2}(a {sup 1}Δ) loss at the output of an electric-discharge singlet oxygen generator. In addition, it can also contribute significantly to the loss of O{sub 2}(a {sup 1}Δ) in the discharge region of the generator. (lasers)

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

    SciTech Connect

    Busch, G.E.

    1984-04-01

    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.

  13. Optical resonator with nonuniform magnification for improving beam uniformity of chemical oxygen iodine lasers

    NASA Astrophysics Data System (ADS)

    Wu, Kenan; Sun, Yang; Huai, Ying; Jia, Shuqin; Chen, Xi; Jin, Yuqi

    2015-02-01

    Unstable resonator with nonuniform magnification for improving the beam uniformity of chemical oxygen iodine lasers is explored for the first time. The magnification of the resonator is a function of the radial coordinate of the polar coordinate system on the front mirror surface. A resonator was designed to have a lower magnification at the center of the resonator than at the edge. The resonator consists of two aspherical mirrors. Method for designing the resonator is given. The energy conservation law and the aplanatic condition were used to derive the designing principle of the two aspherical mirrors. The design result was fitted to polynomial form which is suitable for manufacturing. Numerical experiment was carried out to evaluate the performance of the resonator. The computation was based on coupled simulation of wave optics model and computational fluid mechanics model. Results proved the effectiveness of the design method. The design tends to enhance the intensity near the center of the output beam and cripple that near the edge. Further analysis revealed that this effect is induced because rays of light are reflected more densely at the center of the pupil than at the edge. Therefore, this design affords for a potential approach for improving the near field uniformity of chemical oxygen iodine lasers.

  14. A laser-induced fluorescence method for detecting iodine-129 in the atmosphere using a frequency-doubled neodymium laser

    NASA Astrophysics Data System (ADS)

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

    2013-10-01

    This work reports on research into the fluorescence of 127I129I and 127I2 isotopologues excited by radiation from a frequency-doubled neodymium laser. We determined the wavelengths of excitation radiation that are optimal for the simultaneous detection of the mentioned isotopes being mixed with each other in atmospheric air. A laser-induced fluorescence (LIF) method is proposed to measure the concentrations of 127I129I and 127I2 simultaneously. The paper shows that the minimum measurable fraction of 127I129I molecules mixed with 127I2 is 6.5 10-7, which is more than ten times better than existing results obtained by LIF for monitoring iodine in the atmosphere.

  15. Using a copper-vapor laser (578.2?nm) in a new method of laser fluorescence for molecular iodine isotopes to detect gases in real time

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.; Simanovsky, I. G.; Suganeev, S. V.

    2014-09-01

    This letter deals with the development of a new laser method for simultaneously detecting 127I2, 127I129I and 129I2 in gaseous media, which, in contrast with existing methods, does not require tuning of the laser wavelength. The method is based on exciting fluorescence in iodine isotopologues using copper-vapor laser radiation (578.2?nm) and registering the separate spectral fluorescence line intensities. This method allows high-sensitivity real-time monitoring of isotopologues of molecular iodine-129 and iodine-127 in technological media generated during the reprocessing of spent nuclear fuel, in gaseous emissions from the purification systems of radiochemical plants and in the natural atmosphere.

  16. Focal spot analysis of optical inhomogeneities appearing in the working medium of an iodine photodissociation laser with flashlamp pumping

    NASA Astrophysics Data System (ADS)

    Kachalin, G. N.; Pivkin, D. N.; Polozov, A. A.; Safronov, A. S.; Khudikov, N. M.

    2013-01-01

    We report on the results of experimental studies of optical inhomogeneities appearing in the working medium of an iodine photodissociation laser operating in the inversion accumulation mode and in the free-running mode. The dynamics of evolution of optical inhomogeneities in the free-running mode is studied experimentally.

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

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-10-01

    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 510-3 %/cm. To our knowledge, this is the first observation of positive small signal gain of the amine-based AGIL system.

  19. Chemical oxygen-iodine laser with a cryosorption vacuum pump with different buffer gases

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    A traditional pressure recovery system is the major obstacle to mobile chemical oxygen-iodine laser (COIL) for its huge volume. A cryosorption vacuum pump was used as the pressure recovery system for different buffer gases. It made COIL become a flexible, quiet and pressure-tight. Experiments were carried out on a verti- COIL, which was designed for N2 and energized by a square-pipe jet singlet oxygen generator (JSOG). 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. The great volume efficiency interested researchers.

  20. A computational fluid dynamics simulation of a supersonic chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

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

    2007-05-01

    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. The gain, I II dissociation fraction and temperature at the optical axis, calculated using Heidner's model (R.F. Heidner III et al., J. Phys. Chem. 87, 2348 (1983)), are much lower than those measured experimentally. Agreement with the experimental results was reached by using Heidner's model supplemented by Azyazov-Heaven's model (V.N. Azyazov and M.C. Heaven, AIAA J. 44, 1593 (2006)) where I II(A') and vibrationally excited O II(a1Δ) are significant dissociation intermediates.

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    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.

  2. Chemical oxygen-iodine laser for decommissioning and dismantlement of nuclear facilities

    NASA Astrophysics Data System (ADS)

    Tei, Kazuyoku; Sugimoto, Daichi; Endo, Masamori; Takeda, Shuzaburo; Fujioka, Tomoo

    2000-01-01

    Conceptual designs of a chemical oxygen-iodine laser (COIL) facility for decommissioning and dismantlement (DD) of nuclear facility is proposed. The requisite output power and beam quality was determined base don our preliminary experiments of nonmetal material processing. Assuming the laser power of 30kW, it is derived that the beam quality of M2 equals 36 required to cut a biological shield wall of a nuclear power plant at a cutting speed of 10mm/min. Then the requisite specification of an optical fiber to deliver the laser is calculated. It turned to be quite extreme, core diameter of 1.7mm and NA equals 0.018. The mass flow and heat balance of proposed facility is calculated based on our recent COIL studies. With the high-pressure subsonic mode, the vacuum pump size is minimized compared to the supersonic operation. Finally, the size of the facility is estimated assuming tow-hour continuous operation. It is revealed that such a system can be packed in five railway containers.

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

    SciTech Connect

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

    2010-08-03

    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 (CH{sub 3}I, n-C{sub 3}H{sub 7}I, C{sub 2}H{sub 5}I) with oxygen and nitrogen at the specific energy depositions of {approx}5 J L{sup -1}, pressures of 10 - 25 Torr, and mixture volume of 2.5 L. (lasers)

  4. Speciation of iodine-containing proteins in Nori seaweed by gel electrophoresis laser ablation ICP-MS.

    PubMed

    Romars-Hortas, V; Bianga, J; Moreda-Pieiro, A; Bermejo-Barrera, P; Szpunar, J

    2014-09-01

    An analytical approach providing an insight into speciation of iodine in water insoluble fraction of edible seaweed (Nori) was developed. The seaweed, harvested in the Galician coast (Northwestern Spain), contained 67.71.3 ?g g(-1) iodine of which 25% was water soluble and could be identifies as iodide. Extraction conditions of water insoluble residue using urea, NaOH, SDS and Triton X-100 were investigated. The protein pellets obtained in optimized conditions (after precipitation of urea extracts with acetone), were digested with trypsin and protease XIV. Size exclusion chromatography-ICP-MS of both enzymatic digests demonstrated the occurrence of iodoaminoacids putatively present in proteins. Intact proteins could be separated by gel electrophoresis after an additional extraction of the protein extract with phenol. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE) with laser ablation ICP-MS detection of (127)I indicated the presence of iodine in protein bands corresponding to molecular masses of 110 kDa, 40 kDa, 27 kDa, 20 kDa and 10 kDa. 2D IEF-SDS PAGE with laser ablation ICP-MS (127)I imaging allowed the detection of 5 iodine containing protein spots in the alkaline pI range. PMID:24913873

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

    SciTech Connect

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

    2010-01-15

    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{sup +} laser-induced fluorescence (LIF) spectrum of room-temperature molecular iodine vapor. Over 360 primary and secondary I{sub 2} LIF calibration lines spanning 510-645 nm were identified as calibrant peaks using an instrumental resolution of 1 cm{sup -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 I{sub 2} LIF was tested with measurements of both laser light scattering and Raman spectra. The I{sub 2} 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{sup -1} were achieved with this calibration technique.

  6. Effects of translational nonequilibrium on the performance of a flowing chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Gao, Zhi; Yan, Hai-Xing; Hu, Li-Min

    2003-11-01

    The effect of the translational nonequilibrium on performance modeling of flowing chemical oxygen-iodine lasers (COIL) is emphasized in this paper. The spectral line broadening (SLB) model is a basic factor for predicting the performances of flowing COIL. The Voigt profile function is a well-known SLB model and is usually utilized. In the case of gas pressure in laser cavity less than 5 torr, a low pressure limit expression of the Voigt profile function is used. These two SLB models imply that all lasing particles can interact with monochromatic laser radiation. Basically, the inhomogeneous broadening effects are not considered in these two SLB models and they cannot predict the spectral content. The latter requires consideration of finite translational relaxation rate. Unfortunately, it is rather difficult to solve simultaneously the Navier-Stokes (NS) equations and the conservation equations of the number of lasing particles per unit volume and per unit frequency interval. In the operating condition of flowing COIL, it is possible to obtain a perturbational solution of the conservational equations for lasing particles and deduce a new relation between the gain and the optical intensity, i.e., a new gain-saturation relation. By coupling the gain-saturation relation with other governing equations (such as the NS equations, chemical reaction equations and the optical model of gain-equal-loss), we have numerically calculated the performances of flowing COIL. The present results are compared with those obtained by the common rate-equation (RE) model, in which the Voigt profile function and its low pressure limit expression are used. The difference of different model"s results is great. For instance, in the case of lasing frequency coinciding with the central frequency of line profile and very low gas pressure, the gain saturation relation of the present model is quite different with that of the RE model.

  7. Flowfield measurements in a model scramjet combustion using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Mcdaniel, J. C., Jr.

    1984-01-01

    Preliminary designs were completed for an iodine mixing chamber and the optical setup to be used with a modified wind tunnel in obtaining accurate, spatially resolved measurements of variables in the flowfield of a model nonreacting scramjet combustor. Schematics of the iodine-seeded wind tunnel and a sketch of the charcoal filter for removing the iodine are included along with a cutaway section of the laboratory.

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

    NASA Astrophysics Data System (ADS)

    Mikheyev, Pavel A.; Azyazov, Valeriy N.

    2008-12-01

    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 productionconventional, by means of I2 dissociation in the singlet oxygen flow and with iodine atoms produced externally in the electric dischargewas 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.

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

    NASA Astrophysics Data System (ADS)

    Kryukov, P. G.

    1995-12-01

    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 inexpensive technique and admitted scaling up to energy values which are beyond the reach now with the diodes. This is a pulsed chemical oxygen-iodine laser (COIL) with intracavity frequency doubling. The COIL operates on a laser transition of atomic iodine (1.315 micrometer). The upper laser level populates via energy transfer from metastable oxygen molecules (O2(1(Delta) )-singlet oxygen) which formed in a rather simple chemical reaction between an alkaline solution of hydrogen peroxide and gaseous chlorine. The COIL is a gas laser of low pressure (not more than several torrs), having high output parameters and efficiency. A peculiar mechanism of inversion formation makes it difficult to realize a pulsed mode operation by conventional techniques. In particular, there is a limitation of energy stored in large volume. This problem has been solved in our laboratory by forming of atomic iodine with external exposure on some iodides. As a result a pulsed COIL system with an external initiation arose. High optical quality of an active medium and rather high intensity permit us to get 100% intracavity frequency doubling. The wavelength (657.5 nm) is suitable for pumping of some efficient laser materials such as Cr:LiSAF, and garnets codoped with Cr3+ and TR3+ ions. The proposed laser system has the following advantages: (1) scaling by merely increasing the size of the laser, (2) regulated pulse duration from 20 microseconds, (3) well-collimated beam, and (4) repetition rate of about tens Hz. There is a possibility to use the proposed laser system to pump large-size laser elements of laser-drivers for ICF. It is especially interesting to use the proposed pumping source for chirped pulse amplification. Energy of 100 - 200 J can be obtained with currently available pulsed COILs. Thereby a real ability opens for generation of ultrashort pulses of petawatt level output power.

  10. Optical saturation and extraction from the chemical oxygen-iodine laser medium

    SciTech Connect

    Copeland, D.A.; Bauer, A.H. . Rocketdyne Div.)

    1993-09-01

    A rate equation model for the loaded gain of a flowing chemical oxygen-iodine laser is described. The solution of the model is obtained for the loaded gain when the medium is stimulated by a multimode field. It is shown that optical saturation of the COIL medium is governed by three parameters: the ratio of the collision to Doppler linewidth measuring how much of the total linewidth is accessed; a saturation parameter measuring the field strength required to overcome medium quenching; and a cross-relaxation parameter measuring the ability of the velocity and hyper-fine relaxation to restore homogeneity to the transition. Criteria for the saturation character, homogeneous, inhomogeneous, or mixed, are established. This gain model is used to parametrically examine the sensitivity of the loaded gain and optical extraction efficiency to cavity pressure and to the uncertainty in the magnitude of the velocity cross-relaxation rates. It is shown, under single-mode operating conditions, that the extraction efficiency increases as the rate of velocity cross-relaxation increases and that the saturation behavior of the medium can be totally changed by only modes changes in the cavity operating conditions. The implication when interpreting experimental data and scaling from low to high power operation are briefly discussed and it is shown that interpreting test data without consideration of the factors presented here can lead to substantial error in estimating the power available from the flow.

  11. Light trapping for silicon photovoltaic cells illuminated by solar-pumped lasersemitting at 1064 nm

    NASA Astrophysics Data System (ADS)

    Takeda, Yasuhiko; Ito, Tadashi

    2015-08-01

    We have demonstrated a significant light-trapping effect for a silicon photovoltaic cell using a bandpass filter on the front surface and a diffuse reflector on the back surface, which is coupled with a solar-pumped laser emitting at 1064 nm, as a new approach to highly efficient solar photovoltaics. We carried out Monte-Carlo simulation of the light-trapping process to consider the effects of realistic optical properties of the surface treatments, and clarified the requisites to remarkably improve the absorbance of the cell. A multilayer bandpass filter consisting of TiO2 and SiO2 was employed, in which the thickness of each layer was optimized. A Si surface roughened by acid etching and covered with a Ag layer realized sufficient diffuse reflection properties. The prototype for optical evaluations using a 45-µm-thick Si wafer, which is extremely thin compared with conventional silicon solar cells, almost perfectly absorbed the monochromatic incident light even though the wavelength was very close to the absorption edge.

  12. Computer-controlled multi-parameter mapping of 3D compressible flowfields using planar laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

    Donohue, James M.; Victor, Kenneth G.; Mcdaniel, James C., Jr.

    1993-01-01

    A computer-controlled technique, using planar laser-induced iodine fluorescence, for measuring complex compressible flowfields is presented. A new laser permits the use of a planar two-line temperature technique so that all parameters can be measured with the laser operated narrowband. Pressure and temperature measurements in a step flowfield show agreement within 10 percent of a CFD model except in regions close to walls. Deviation of near wall temperature measurements from the model was decreased from 21 percent to 12 percent compared to broadband planar temperature measurements. Computer-control of the experiment has been implemented, except for the frequency tuning of the laser. Image data storage and processing has been improved by integrating a workstation into the experimental setup reducing the data reduction time by a factor of 50.

  13. The subsonic chemical oxygen-iodine laser : comparison of a theoretical model to experiments in the 30 W range

    NASA Astrophysics Data System (ADS)

    Churassy, S.; Bouvier, A. J.; Bouvier, A.; Erba, B.; Setra, M.

    1994-10-01

    The performances of a small scale subsonic chemical oxygen-iodine laser have been improved, the output laser power being increased from 5 to 34 W, with the same gas pumping system. At this power range, we have shown that the modeling of the laser must include the temperature effects on the reaction kinetics. Our model shows also that the addition of a buffer gas such as SF6 achieves a significant cooling of the active medium, which in turn allows a better laser power extraction. Les performances d'un laser subsonique iode-oxygne chimique petite chelle ont t amliores, la puissance laser tant augmente de 5 W 34 W avec le mme ensemble de pompage. Nous avons montr que, dans ce domaine de puissance, la modlisation du laser doit inclure les effets de temprature sur les cintiques des ractions. Notre modle montre galement que l'adjonction d'un gaz tampon tel que SF6 conduit un refroidissement important du milieu actif, permettant alors une meilleure extraction de la puissance laser.

  14. Prototype of a Laser-Induced Fluorescence Ground-Based Instrument for Measurements of Atmospheric Iodine Monoxide (IO)

    NASA Astrophysics Data System (ADS)

    Thurlow, M. E.; Co, D. T.; Hanisco, T. F.; Lapson, L. B.; Anderson, J. G.

    2008-12-01

    High abundances of iodine monoxide (IO) are known to exist and to participate in local photochemistry of the marine boundary layer: (1) IO participates in depletion episodes of O3 and in the removal of mercury in the Arctic polar spring by enhancing atomic Br mixing ratios. Recent observations and computer simulations suggest that mercury sequestration is closely tied to halogen photochemistry and that gaseous atomic Hg depletion can be enhanced significantly by the presence of small amounts of iodine-containing compounds. (2) IO and higher- order iodine oxides are involved in the formation of new particles in coastal marine environments. Studies using smog chamber experiments simulating coastal atmospheric conditions have demonstrated that new particles can form from condensable iodine-containing vapors and that their concentrations over the open ocean are sufficient to influence marine particle formation. (3) IO has also been shown to affect the oxidizing capacity of the troposphere by altering the partitioning of NO2/NO and HO2/HO and by activating chlorine and bromine in sea salt aerosols. In the stratosphere, these same processes can lead to enhanced ozone loss rates. Detailed photochemical models that include iodine photochemistry, however, are hampered by the lack of observational data. The distribution of IO in vertical, horizontal, and temporal coordinates is unknown, so the impact of IO on global photochemistry cannot be predicted. The resolution of these important scientific issues requires an in situ IO instrument. A fully functional nanosecond Nd:YAG-pumped Ti:Sapphire laser system and a prototype IO ground-based instrument have been built in our lab. With the current setup, the laser system was situated 10 m from the field station, and the laser light was coupled via an optical fiber. With the use of highly efficient fluorescence detection optics and photon counting techniques, sensitivities of better than 0.1 ppt in 1 s for IO was achieved in the laboratory and 1-2 ppt in the field. The design of the instrument and data acquisition system will be described. The prototype was initially deployed to the Northeastern University Marine Science Center in Nahant, MA in August 2007. Recent developments in the design and sensitivity of the instrument will be discussed. A modified version of this new system will, in time, be capable of being integrated with the existing instrumentation used for the detection of halogen (ClO, BrO), nitrogen (NO2), and hydrogen (OH and HO2) free radicals.

  15. Analytic study of the chain dark decomposition reaction of iodides - atomic iodine donors - in the active medium of a pulsed chemical oxygen-iodine laser: 2. Limiting parameters of the branching chain dark decomposition reaction of iodides

    SciTech Connect

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

    2009-08-31

    The final stages in the development of a branching chain decomposition reaction of iodide in the active medium of a pulsed chemical oxygen-iodine laser (COIL) are analysed. Approximate expressions are derived to calculate the limiting parameters of the chain reaction: the final degree of iodide decomposition, the maximum concentration of excited iodine atoms, the time of its achievement, and concentrations of singlet oxygen and iodide at that moment. The limiting parameters, calculated by using these expressions for a typical composition of the active medium of a pulsed COIL, well coincide with the results of numerical calculations. (active media)

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

    NASA Astrophysics Data System (ADS)

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

    2008-11-01

    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.

  17. Digital control of an iodine stabilized He-Ne laser by using a personal computer and a simple electronic system

    NASA Astrophysics Data System (ADS)

    Panteli?, Dejan V.; Pani?, Bratimir M.; Kova?evi?, Aleksander G.

    2003-06-01

    An electronic system used for active control and optical frequency stabilization of a He-Ne laser is described. It is based on digital acquisition and signal processing, using minimum of analog electronics, and a personal computer (PC). Main functions of the system: phase sensitive detection, automatic control, and user interface, are performed in software. Simultaneous frequency and iodine cell temperature stabilization algorithm is described. Electronic system is compact (occupies only desktop PC case), inexpensive (commercial, of-the-shelf, components are mostly used), and can be easily upgraded and reprogrammed (new stabilization algorithms can be implemented). It is now a part of the primary length standard of Yugoslavia.

  18. Planar measurement of flow field parameters in a nonreacting supersonic combustor using laser-induced iodine fluorescence

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    A nonintrusive optical technique, laser-induced iodine fluorescence, has been used to obtain planar measurements of flow field parameters in the supersonic mixing flow field of a nonreacting supersonic combustor. The combustor design used in this work was configured with staged transverse sonic injection behind a rearward-facing step into a Mach 2.07 free stream. A set of spatially resolved measurements of temperature and injectant mole fraction has been generated. These measurements provide an extensive and accurate experimental data set required for the validation of computational fluid dynamic codes developed for the calculation of highly three-dimensional combustor flow fields.

  19. Influence of parameters of gas medium on the fluorescence of iodine molecules 129I2, 127I129I and 127I2 excited by semiconductor laser radiation

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2012-12-01

    Calculated and experimental results of studies of the influence of vapor temperature of iodine molecules (129I2, 127I129I, and 127I2) and pressure of the analyzed medium on the intensity of fluorescence of the molecules excited by semiconductor laser radiation in the red spectrum region are reported. It is demonstrated that depending on the wavelength of laser radiation there exist different ranges of temperatures and pressure values at which the fluorescence intensities of each of the indicated iodine molecules reach their maximum values.

  20. On-line molecular iodine isotopologue detection in gaseous media during spent nuclear fuel reprocessing using a laser-induced fluorescence method

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-06-01

    The paper reports on on-line measurement of the {}129{{\\text{I}}2}, 127I129I, and {}127{{\\text{I}}2} concentrations during spent nuclear fuel (SNF) reprocessing using a laser-induced fluorescence method. A He-Ne laser (632.8 nm) was used as a fluorescence excitation source. The detection limits obtained for molecular iodine isotopologue concentrations demonstrate the possibility of using this method for iodine control both in gaseous technological media generated during SNF reprocessing and after passing through the gas purification system (in atmosphere emission).

  1. A Ground-Based Instrument for the Laser-Induced Fluorescence Detection of Coastal Iodine Monoxide (IO)

    NASA Astrophysics Data System (ADS)

    Hannun, R. A.; Thurlow, M. E.; O'Brien, A.; Co, D. T.; Hanisco, T. F.; Lapson, L. B.; Anderson, J.

    2011-12-01

    The photochemistry of iodine monoxide (IO) within the marine boundary layer plays a role in the catalytic loss cycles of surface ozone and potentially leads to the nucleation of marine aerosols. Biogenic emissions of molecular iodine and organo-halide precursor molecules account for the largest sources of IO in marine and coastal environments. Due to the inhomogeneous distribution of atmospheric IO in conjunction with low mixing ratios of less than 10 ppt, high sensitivity in-situ measurements are needed in order to better understand the impact of IO photochemistry in a quantifiable way. To address these challenges, a laser-induced fluorescence instrument has been developed, with a nanosecond-pulsed Nd:YAG-pumped Ti:Sapphire laser system. Through efficient optical design and fluorescence detection, we are able to operate in the sensitivity threshold of 1 ppt per minute for IO. Further design considerations included the development of a mobile, weatherproof instrument configuration, which can sustain deployment in a variety of field conditions. In order to validate the detection technique, the instrument was deployed at Shoals Marine Laboratory in Maine from August-September 2011. Instrument design considerations as well as preliminary results of the detection of IO from laminaria digitata, a kelp species present in coastal New England sites, will be presented.

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

    SciTech Connect

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

    2011-03-15

    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 and their mixing with the iodine-containing gas. The main processes affecting the dynamics of the gas temperature and gain are revealed. The simulation results obtained using the 2D model agree well with the experimental data on the mixture gain. A subsonic oxygen-iodine laser in which singlet oxygen is generated by a 350 W transverse RF discharge excited in an oxygen flow at a pressure P = 10 Torr and the discharge tube wall is covered with mercury oxide is simulated. The simulated mixing system is optimized in terms of the flow rate and the degree of preliminary dissociation of the iodine flow. The optimal regime of continuous operation of a subsonic electric-discharge oxygen-iodine laser is found.

  3. Laser and solar-photovoltaic space power systems comparison. II.

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Stripling, J.; Enderson, T. M.; Humes, D. H.; Davis, W. T.

    1984-01-01

    A comparison of total system cost is made between solar photovoltaic and laser/receiver systems. The laser systems assume either a solar-pumped CO2 blackbody transfer laser with MHD receiver or a solar pumped liquid neodymium laser with a photovoltaic receiver. Total system costs are less for the laser systems below 300 km where drag is significant. System costs are highly dependent on altitude.

  4. 70-J repped pulse (0.5 Hz) closed-cycle photolytic atomic iodine laser at 1.315 microns with excellent BQ, coherence length, and reliable operation

    NASA Astrophysics Data System (ADS)

    Schlie, L. A. V.; Rathge, Robert D.

    1992-05-01

    The performance of a repetitively pulsed, high energy, closed cycle photolytic atomic iodine lasers at 1.315 microns is presented. Using an I2 removal system for the photolyzed C3F7I laser fuel, more than 70 joules/pulse was acquired in the fundamental mode from a M equals 3 confocal unstable resonator at a 0.5 Hz repetition rate. The closed cycle chemical scrubber system consisted of a condensative-evaporative section, two Cu wool I2 reactor sections, and an internal turbo-blower. This closed cycle system provided C2F7I gas at 10 - 60 torr absent of I2. The turbo-blower produced longitudinal flow velocities greater than 10 m/s through the 150 cm long by 7.5 X 7.5 cm2 cross sectional photolytic iodine gain region. In addition to the high energy output, the resulting 10 - 12 microsecond(s) ec laser had a beam quality of less than 1.5 times diffraction limited with a coherence length greater than 45 meters, and a polarization extinction ratio better than 100:1. Projections from this pulsed photolytic atomic iodine laser technology to larger energies, high repetition rates, and variable pulsewidths are discussed. In addition, the performance of cw photolytically excited atomic iodine laser at 1.315 micrometers is reported which has excellent scaling potential. Volumetric extractable cw powers of 55 watts/liter are reported with a small signal gain coefficient of 2%/cm. The potential of enhancing the cw powers to kilowatt levels plus producing variable pulsewidth, repetition rate iodine laser using an internal electro-optical modulator are also discussed.

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

    PubMed

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

    2007-07-26

    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

  6. Interpretation of In-Situ Measurements of Iodine Monoxide in Coastal Regions Using Laser-Induced Fluorescence Spectroscopy

    NASA Astrophysics Data System (ADS)

    Furneaux, K. L.; Whalley, L. K.; Heard, D. E.

    2009-04-01

    Iodine species are present in coastal and open ocean regions due to the release of I2 and iodocarbons from macro and micro algae. The photolysis of these molecules yields iodine atoms, which react with ozone to produce iodine monoxide (IO). IO is involved in ozone depletion cycles, the partitioning of HOx and NOx, and the formation and growth of new particles. A novel point source Laser Induced Fluorescence (LIF) instrument was deployed to measure IO in September 2006 at Roscoff, France as part of the Reactive Halogens in the Marine Boundary Layer (RHaMBLe) programme (1 instrument uncertainty = 23%)1. The maximum IO mixing ratio was 30 7.1 pptV (10 s integration period, limit of detection = 1.4 pptV) at this semi-polluted coastal site (NOx levels = 1 - 5 ppbV). The closest macroalgae beds known to strongly emit I2 (laminaria) were ~ 300 m from the LIF instrument. IO displayed a strong anti-correlation with tidal height which is consistent with previous studies. IO was also dependent on solar irradiation and meteorological conditions. The dominant source of IO at this site was the photolysis of I2. The measurements provided by this instrument aim to address the main uncertainties associated with iodine chemistry. Co-ordinated measurement of IO by point source (LIF) and spatially averaged (Long Path Differential Optical Absorption Spectroscopy) instruments confirm the presence of IO hotspots due to non-uniform macroalgae distribution at this location (resulting in a spatially variable I2 source). The ratio of point source/spatially averaged IO is determined by meteorological conditions and distance of the instrument from macroalgae beds. Co-located point source I2 (Broadband Cavity Ringdown Spectroscopy) and IO (LIF) measurements correlated on some days but cannot be explained by our current knowledge of iodine chemistry. The influence of NOx on IO has been investigated. The detection of IO by LIF at the Roscoff site shows that IO can survive in a high NOx environment, at a distance from the iodine source region. The LIF measurements display an anti-correlation with NOx. A modelling study shows that this is due to an iodine recycling scheme via IONO2. The effect of NO2 is to initially lead to IO suppression (displayed by an anti-correlation of IO with NOx) and then to prolong the atmospheric lifetime of IO through decomposition of IONO2. Night-time IO was detected on two out of four nights at levels of 1 - 2 pptV, providing further evidence for the presence of night-time IO. The night-time source of I atoms is proposed to be via I2 + NO3 ?? I + INO3, 2,3. Co-located point source measurements of IO and particle number provide clear evidence for the link between IO and new particle formation. Over 18 days of simultaneous measurements, IO and particle number displayed a linear relationship. On all occasions, IO levels increased before an increase in particle number was observed. The influence of IO on the important daytime oxidants OH and HO2 has been investigated by modelling studies. IO was found to decrease the HO2/OH ratio due conversion of HO2 to OH via (HO2 + IO ?? HOI, HOI + h? ?? OH + I). The high levels of IO detected at Roscoff can result in an enhancement of OH at up to 50%. However, the impact of IO on HOx decreases as NOx levels increase, until IO actually results in a decrease in OH (NOx > 1.55 ppbV). Whalley et. al. (2007), J. Atmos. Chem. 58: 19 - 39. Chambers, R. M. et al (1992), Journal of Physical Chemistry, 96, 3321-3331. Saiz-Lopez, A. and J. M. C. Plane (2004), GRL, 31, 19215-19218.

  7. Iodine poisoning

    MedlinePLUS

    Iodine is a naturally occurring chemical. Small amounts are needed for good health. However, large doses can ... Children are especially sensitive to the effects of iodine. NOTE: Iodine is found in certain foods. However, ...

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

    NASA Astrophysics Data System (ADS)

    Masuda, Taizo; Nakamura, Tomonari; Endo, Masamori

    2010-09-01

    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.

  9. 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)

    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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-03-01

    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.

  11. Power optimization of small-scale chemical oxygen-iodine laser with jet-type singlet oxygen generator

    SciTech Connect

    Blayvas, I.; Barmashenko, B.D.; Furman, D.; Rosenwaks, S.; Zagidullin, M.V.

    1996-12-01

    Studies of power optimization of a 5-cm gain length chemical oxygen-iodine laser (COIL) energized by a jet-type singlet oxygen generator (JSOG) are presented. For 10 mmol/s of Cl{sub 2} flow rate, output power of 132 W with chemical efficiency of 14.5% was obtained without a water vapor trap. 163 W and 18% were achieved when coholed (173 K) He was introduced downstream of the JSOG; under these conditions, the small-signal gain was estimated to be 0.32% cm{sup {minus}1}. 190 W and 10.5% were obtained for 20 mmol/s of Cl{sub 2} flow rate. Replacing He by N{sub 2} as a buffer gas resulted in a 13% power decrease only. The main key for increasing the chemical efficiency of a COIL without a water vapor trap for a given iodine-oxygen mixing system is found to be high oxygen pressure and low water vapor pressure inside the reaction zone of the JSOG. The last goal was achieved by optimizing the composition and temperature of the basic hydrogen-peroxide solution (BHP). The experimental results are discussed and related to the composition and flow conditions of the gaseous reactants and of the BHP.

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

    NASA Technical Reports Server (NTRS)

    1982-01-01

    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.

  13. Data acquisition and control system with a programmable logic controller (PLC) for a pulsed chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Yu, Haijun; Li, Guofu; Duo, Liping; Jin, Yuqi; Wang, Jian; Sang, Fengting; Kang, Yuanfu; Li, Liucheng; Wang, Yuanhu; Tang, Shukai; Yu, Hongliang

    2015-02-01

    A user-friendly data acquisition and control system (DACS) for a pulsed chemical oxygen -iodine laser (PCOIL) has been developed. It is implemented by an industrial control computer,a PLC, and a distributed input/output (I/O) module, as well as the valve and transmitter. The system is capable of handling 200 analogue/digital channels for performing various operations such as on-line acquisition, display, safety measures and control of various valves. 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 PCOIL. The DACS system has been programmed using software programmable logic controller (PLC). Using this DACS, more than 200 runs were given performed successfully.

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

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

    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.

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

    SciTech Connect

    Pichugin, S Yu

    2012-09-30

    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)

  16. 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

    SciTech Connect

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

    2009-02-28

    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. (active media)

  17. Optical frequency standard based on a Nd:YAG laser stabilised by saturated absorption resonances in molecular iodine using second-harmonic radiation

    SciTech Connect

    Skvortsov, Mikhail N; Okhapkin, M V; Nevsky, A Yu; Bagaev, Sergei N

    2004-12-31

    The results of studies devoted to the development of the optical frequency standard based on a diode-pumped 1064-nm single-frequency ring Nd:YAG laser with intracavity frequency doubling are presented. The laser frequency was stabilised by saturated absorption resonances in molecular iodine at the second-harmonic frequency of the laser (at 532 nm). The saturated absorption resonances were observed in an external luminescent cell. The relative long-term frequency stability achieved in experiments was {approx}6x10{sup -15}. The physical and technical factors affecting the long-term frequency stability and reproducibility are investigated. (optical metrology and quantum frequency standards)

  18. Laser power transmission

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.

    1992-01-01

    An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

  19. Experimental study on an all gas-phase iodine laser using microwave discharge of Cl2/He as a Cl atoms source

    SciTech Connect

    Tang Shukai; Duo Liping; Jin Yuqi; Yu Haijun; Wang Jian; Sang Fengting

    2006-09-20

    Microwave discharge of a Cl2/He mixture as a simple, clean and efficient Cl atom generator was used for an all gas-phase iodine laser study. Sufficient NCl(a1Delta) was produced through the reaction of HN3+2Cl {yields} NCl(a1Delta)+HCl+N2. The energy transfer reaction of I(2P3/2)+NCl(a1Delta) {yields} I(2P1/2)+NCl(X3Sigma) was observed. A population inversion was observed directly by using a 1315 nm tunable diode laser by scanning the entire line shape of the (3,4) hyperfine transition of iodine, and a small signal gain of 5x10-5 cm-1 was obtained.

  20. Deactivation rate of I{sub 2} molecules (X, v {>=} 30) in the medium of a chemical oxygen-iodine laser

    SciTech Connect

    Pichugin, S Yu

    2008-08-31

    The effective deactivation rate constants are calculated for I{sub 2}(X) molecules at vibrational levels with v {>=} 30 colliding with N{sub 2} and O{sub 2} molecules in the medium of a chemical oxygen-iodine laser. The calculated constants (4x10{sup -12} cm{sup 3} s{sup -1} and 3x10{sup -12} cm{sup 3} s{sup -1}) are less by half plus than the corresponding constants found earlier in the paper of Lawrence et al., where the dissociation of I{sub 2} was neglected in calculations. (lasers, active media)

  1. Iodine monofluoride 140-kW laser - Small signal gain and operating parameters

    NASA Technical Reports Server (NTRS)

    Dlabal, M. L.; Hutchinson, S. B.; Eden, J. G.; Verdeyen, J. T.

    1981-01-01

    Output energies in excess of 4 mJ in a 30-nsec FWHM pulse (140-kW peak power) have been obtained from a discharge-pumped IF laser for a cavity output coupling of 35%. In addition, oscillation on a new transition of the IF (E-A) band at 472.7 nm has been observed. By measurement of the output power of the laser for various values of output mirror transmission, the small signal gain and loss coefficients were found to be (3.1 + or - 0.7)%/cm and 0.3%/cm, respectively.

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

    SciTech Connect

    Berg, M.A.

    1985-09-01

    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)

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

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

    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' 3Π 2u), I II(A 3Π 1u) and O II(a1Δ 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(X1Σ + 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(1Δ). The loss of O II(1Δ) 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.

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

    NASA Astrophysics Data System (ADS)

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

    2007-07-01

    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(aΔg1) 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'Π2u3), I2(AΠ1u3), and O2(aΔg1,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(XΣg +1,v).

  5. Gas-Flow Slab RF Discharge as a Source of Singlet Delta Oxygen for Oxygen Iodine Laser

    NASA Astrophysics Data System (ADS)

    Ionin, Andrey A.; Klimachev, Yurii M.; Kochetov, Igor V.; Napartovich, Anatoly P.; Rulev, Oleg A.; Seleznev, Leonid V.; Sinitsyn, Dmitry V.

    2010-10-01

    Results of experimental and theoretical study of singlet delta oxygen (SDO) production in transverse gas flow RF slab discharge for an electric discharge oxygen-iodine laser are presented. The electric discharge facility operating in both pulse-periodic and CW mode was manufactured: gas flow duct including multi-path cryogenic heat exchanger, dielectric slab channel, and slab electrode system incorporated in the channel for RF discharge ignition. Experiments on SDO production in transverse gas flow RF discharge were carried out. SDO production depending on gas mixture content and pressure, gas flow velocity, low-frequency modulation of RF power and RF discharge power was experimentally studied. It was shown that SDO yield increased with gas pressure decrease, gas flow deceleration and helium dilution of oxygen at the same input power. CW RF discharge was demonstrated to be the most efficient for SDO production at the same averaged input power of RF discharge. SDO yield was demonstrated to be not less than 10%.

  6. Solar Pump

    NASA Technical Reports Server (NTRS)

    Pique, Charles

    1987-01-01

    Proposed pump moves liquid by action of bubbles formed by heat of sun. Tube of liquid having boiling point of 100 to 200 degrees F placed at focal axis of cylindrical reflector. Concentrated sunlight boils liquid at focus, and bubbles of vapor rise in tube, carrying liquid along with them. Pressure difference in hot tube sufficient to produce flow in large loop. Used with conventional flat solar heating panel in completely solar-powered heat-storage system.

  7. Carrier phases for iodine in the Allende meteorite and their associated Xe-129(r)/I-127 ratios - A laser microprobe study

    NASA Technical Reports Server (NTRS)

    Kirschbaum, C.

    1988-01-01

    This paper presents the results of a study of the carrier phases of iodine in the Allende meteorite and their associated Xe-129(r)/I-127 ratios, obtained using a new high-sensitivity low-blank mass spectrometer coupled with a low-blank laser extraction system. Two types of experiments were performed: a survey of the Xe-129(r) amounts in unirradiated specimens of fine-grained assemblages and individual coarse mineral grains, and a study of the relationship between chlorine and iodine in irradiated samples of the inclusions, in which the Xe-129(r)/I-127 ratios were determined for various minerals. As a by-product of these measurements, the Ar-40/Ar-39 ages were obtained along with some results on trapped Xe components. A schematic diagram of the new mass spectrometer system is included.

  8. Generation of singlet oxygen for an oxygen-iodine laser in a radio-frequency discharge

    SciTech Connect

    Braginskii, O V; Vasil'eva, A N; Klopovskii, K S; Kovalev, A S; Lopaev, D V; Mankelevich, Yu A; Popov, N A; Rakhimov, Aleksandr T; Rakhimova, T V

    2005-01-31

    The generation of singlet oxygen (SO) in a radio-frequency discharge (13.56 MHz) in the gas flow was investigated experimentally and theoretically. The oxygen pressure was varied from 2 to 20 Torr and the energy deposition in gas from 10 to 2000 J mmol{sup -1}. The saturation of the SO concentration with increasing the energy deposition was shown to arise from the three-body process of SO quenching by atomic oxygen. Removing atomic oxygen allowed a 2.5-fold increase in the ultimate SO concentration at the discharge output. For an oxygen pressure of 15 Torr, the SO fraction amounts to 10%. (active media. lasers)

  9. Kinetic-fluid dynamics modeling of I{sub 2} dissociation in supersonic chemical oxygen-iodine lasers

    SciTech Connect

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

    2009-09-15

    The mechanism of I{sub 2} dissociation in supersonic chemical oxygen-iodine lasers (COILs) is studied applying kinetic-fluid dynamics modeling, where pathways involving the excited species I{sub 2}(X {sup 1}SIGMA{sub g}{sup +},10<=v<25), I{sub 2}(X {sup 1}SIGMA{sub g}{sup +},25<=v<=47), I{sub 2}(A{sup '} {sup 3}PI{sub 2u}), I{sub 2}(A {sup 3}PI{sub 1u}), O{sub 2}(X {sup 3}SIGMA{sub g}{sup -},v), O{sub 2}(a {sup 1}DELTA{sub g},v), O{sub 2}(b {sup 1}SIGMA{sub g}{sup +},v), and I({sup 2}P{sub 1/2}) as intermediate reactants are included. The gist of the model is adding the first reactant and reducing the contribution of the second as compared to previous models. These changes, recently suggested by Azyazov, et al. [J. Chem. Phys. 130, 104306 (2009)], significantly improve the agreement with the measurements of the gain in a low pressure supersonic COIL for all I{sub 2} flow rates that have been tested in the experiments. In particular, the lack of agreement for high I{sub 2} flow rates, which was encountered in previous models, has been eliminated in the present model. It is suggested that future modeling of the COIL operation should take into account the proposed contribution of the above mentioned reactants.

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

    NASA Astrophysics Data System (ADS)

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

    2010-02-01

    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.

  11. Planar Laser-Induced Iodine Fluorescence Measurements in Rarefied Hypersonic Flow

    NASA Technical Reports Server (NTRS)

    Cecil, Eric; McDaniel, James C.

    2005-01-01

    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.

  12. Design investigation of solar powered lasers for space applications

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

    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.

  13. Iodine Deficiency

    MedlinePLUS

    ... poor iodine intake in pregnancy predicts lower child IQ Read More February 22, 2013 2 New ICCIDD ... Thyroid Diseases & Conditions) Cancer of the Thyroid Public Health Statements Potassium Iodide Corporate Information & Opportunities Tools & Resources ...

  14. The Development and Deployment of a Ground-Based, Laser-Induced Fluorescence Instrument for the In Situ Detection of Iodine Monoxide Radicals

    NASA Technical Reports Server (NTRS)

    Thurlow, M. E.; Co, D. T.; O'Brien, A. S.; Hannun, R. A.; Lapson, L. B.; Hanisco, T. F.; Anderson, J. G.

    2014-01-01

    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 1012. The IO radical is measured by detecting laser-induced fluorescence at wavelengths longer that 500 nm. Tunable visible light is used to pump the A23/2 (v = 2) ? X23/2 (v = 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.

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

    SciTech Connect

    Thurlow, M. E. Hannun, R. A.; Lapson, L. B.; Anderson, J. G.; Co, D. T.; Argonne-Northwestern Solar Energy Research Center and Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208-3113 ; O'Brien, A. S.; Department of Civil and Environmental Engineering, Princeton University, Princeton, New Jersey 08544 ; Hanisco, T. F.; NASA Goddard Space Flight Center, Code 614, Greenbelt, Maryland 20771

    2014-04-15

    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}Π{sub 3/2} (v{sup ′} = 2) ← X{sup 2}Π{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.

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

    PubMed

    Thurlow, M E; Co, D T; O'Brien, A S; Hannun, R A; Lapson, L B; Hanisco, T F; Anderson, J G

    2014-04-01

    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(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(2)?3/2 (v(') = 2) ? X(2)?3/2 (v(?) = 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. PMID:24784629

  17. Quantum-well lasers for direct solar photopumping

    NASA Technical Reports Server (NTRS)

    Unnikrishnan, Sreenath; Anderson, Neal G.

    1993-01-01

    Semiconductor lasers directly photopumped by focused sunlight may be viable sources of coherent light for intersatellite communications and other low-power spaceborne applications. In this work, we theoretically explore the possibility of realizing such devices. We specifically assess solar pumped operation of separate-confinement-quantum-well heterostructure (SCQWH) lasers based on InGaAs, GaAs, and AlGaA, as fabrication technology for these lasers is mature and they can operate at very low thresholds. We develop a model for step-index single-well SCQWH lasers photopumped by sunlight, examine how threshold solar photoexcitation intensities depend upon material and structure parameters, design optimum structures for solar-pumped operation, and identify design tradeoffs. Our results suggest that laser action should be possible in properly designed structures at readily achievable solar concentrations and that optimum designs for solar-pumped SCQWH lasers differ significantly from those for analogous current injection devices.

  18. Generation of iodine L-shell X-rays under excitation of large CF{sub 3}I clusters by femtosecond laser radiation

    SciTech Connect

    Gordienko, Vyacheslav M; Dzhidzhoev, M S; Zhvaniya, I A; Pribytkov, Andrei V; Trubnikov, Dmitrii N; Fedorov, D O

    2012-11-30

    The use of clusters of polyatomic molecules with a relatively low ionisation energy ({approx}10 eV) is proposed for the efficient production of X-ray radiation. We have observed for the first time the generation of characteristic X-ray radiation due to L transitions in iodine atoms under the high-intensity femtosecond laser irradiation of molecular CF{sub 3}I clusters, which were a small admixture to Ar carrier gas. The X-ray conversion efficiency amounts to {approx}10{sup -6} (for a yield of {approx}10{sup 7} photons per pulse), which is an order of magnitude higher than the efficiency we obtained in the case of argon clusters under comparable conditions. (letters)

  19. Chemical oxygen-iodine laser (COIL) beam quality predictions using 3D Navier-Stokes (MINT) and wave optics (OCELOT) codes

    NASA Astrophysics Data System (ADS)

    Lampson, Alan I.; Plummer, David N.; Erkkila, John H.; Crowell, Peter G.; Helms, Charles A.

    1998-05-01

    This paper describes a series of analyses using the 3-d MINT Navier-Stokes and OCELOT wave optics codes to calculate beam quality in a COIL laser cavity. To make this analysis tractable, the problem was broken into two contributions to the medium quality; that associated with microscale disturbances primarily from the transverse iodine injectors, and that associated with the macroscale including boundary layers and shock-like effects. Results for both microscale and macroscale medium quality are presented for the baseline layer operating point in terms of single pass wavefront error. These results show that the microscale optical path difference effects are 1D in nature and of low spatial order. The COIL medium quality is shown to be dominated by macroscale effects; primarily pressure waves generated from flow/boundary layer interactions on the cavity shrouds.

  20. Iodine Satellite

    NASA Technical Reports Server (NTRS)

    Kamhawi, Hani; Dankanich, John; Martinez, Andres; Petro, Andrew

    2015-01-01

    The Iodine Satellite (iSat) spacecraft will be the first CubeSat to demonstrate high change in velocity from a primary propulsion system by using Hall thruster technology and iodine as a propellant. The mission will demonstrate CubeSat maneuverability, including plane change, altitude change and change in its closest approach to Earth to ensure atmospheric reentry in less than 90 days. The mission is planned for launch in fall 2017. Hall thruster technology is a type of electric propulsion. Electric propulsion uses electricity, typically from solar panels, to accelerate the propellant. Electric propulsion can accelerate propellant to 10 times higher velocities than traditional chemical propulsion systems, which significantly increases fuel efficiency. To enable the success of the propulsion subsystem, iSat will also demonstrate power management and thermal control capabilities well beyond the current state-of-the-art for spacecraft of its size. This technology is a viable primary propulsion system that can be used on small satellites ranging from about 22 pounds (10 kilograms) to more than 1,000 pounds (450 kilograms). iSat's fuel efficiency is ten times greater and its propulsion per volume is 100 times greater than current cold-gas systems and three times better than the same system operating on xenon. iSat's iodine propulsion system consists of a 200 watt (W) Hall thruster, a cathode, a tank to store solid iodine, a power processing unit (PPU) and the feed system to supply the iodine. This propulsion system is based on a 200 W Hall thruster developed by Busek Co. Inc., which was previously flown using xenon as the propellant. Several improvements have been made to the original system to include a compact PPU, targeting greater than 80 percent reduction in mass and volume of conventional PPU designs. The cathode technology is planned to enable heaterless cathode conditioning, significantly increasing total system efficiency. The feed system has been designed to include iodine compatible control valves with internal heaters and temperature sensors to coincide with the iodine-compatible thruster. A key advantage to using iodine as a propellant is that it may be stored in the tank as an unpressurized solid on the ground and before flight operations. During operations, the tank is heated to vaporize the propellant. Iodine vapor is then routed through custom flow control valves to control mass flow to the thruster and cathode assembly. The thruster then ionizes the vapor and accelerates it via magnetic and electrostatic fields, resulting in high specific impulse, characteristic of a highly efficient propulsion system. The iSat spacecraft is a 12-unit (12U) CubeSat with dimensions of about 8 inches x 8 inches x 12 inches (20 centimeters x 20 centimeters x 30 centimeters). The spacecraft frame will be constructed from aluminum with a finish to prevent iodine-driven corrosion. The iSat spacecraft includes full three-axis control and will leverage heat generated by spacecraft components and radiators for a passive thermal control system. After the CubeSat has successfully detached from its launch vehicle, it will deploy its solar panels, correct for tip-off and maintain attitude control before ground contact. An initial check-out period of two weeks is planned for testing all subsystems. The spacecraft will charge the power system while in sunlight, using momentum wheels and magnetic torque rods to rotate the vehicle to the required attitude.

  1. Radioactive iodine uptake

    MedlinePLUS

    Iodine uptake test; RAIU ... to swallow a liquid or capsule containing radioactive iodine. After a certain period of time (usually 4 ... have: Diarrhea (may decrease absorption of the radioactive iodine) Had recent CT scans using intravenous or oral ...

  2. Hair Iodine for Human Iodine Status Assessment

    PubMed Central

    Prejac, Juraj; Vinjevi?, Vjeran; Skalnaya, Margarita G.; Mimica, Ninoslav; Drmi?, Stipe; Skalny, Anatoly V.

    2014-01-01

    Background: Today, human iodine deficiency is, after iron, the most common nutritional deficiency in developed European and underdeveloped third world countries. A current biological indicator of iodine status is urinary iodine, which reflects very recent iodine exposure; a long-term indicator of iodine status remains to be identified. Methods: We analyzed hair iodine in a prospective, observational, cross-sectional, and exploratory study involving 870 apparently healthy Croatians (270 men and 600 women). Hair iodine was analyzed with inductively coupled plasma mass spectrometry. Results: The hair iodine median was 0.499??g/g, and was 0.482 and 0.508??g/g for men and women respectively, suggesting no sex-related difference. We studied hair iodine uptake by analyzing the logistic sigmoid saturation curve of the median derivatives to assess iodine deficiency, adequacy, and excess. We estimated overt iodine deficiency to occur when hair iodine concentration was below 0.10.15??g/g. Then there was a saturation range interval of about 0.12.0??g/g where the deposition of iodine in the hair was linearly increasing (R2=0.994). Eventually, the sigmoid curve became saturated at about 2.0??g/g and upward, suggesting excessive iodine exposure. Conclusion: Hair appears to be a valuable and robust biological indicator tissue for assessing long-term iodine status. We propose that an adequate iodine status corresponds with hair iodine uptake saturation of 0.5650.739??g/g (5565%). PMID:24446669

  3. Dependence of the molecular iodine B-state predissociation induced by a femtosecond laser pulse on pulse phase modulation

    SciTech Connect

    Kostyukevich, Yu I; Umanskii, Stanislav Ya

    2011-12-31

    The processes of pumping and laser-induced predissociation of B-states of the I{sub 2} molecule under the action of femtosecond laser pulses are considered theoretically. An analytical formula is derived, which describes the dependence of the predissociation on such parameters of femtosecond pulses as spectral chirp, spectral width and delay time between pulses. The formula is used to calculate numerically the dependence of the predissociation yield on the parameters of the phase modulation of the pump pulse and coupling pulse.

  4. Iodine volatility. [PWR; BWR

    SciTech Connect

    Beahm, E.C.; Shockley, W.E.

    1984-01-01

    The ultimate aim of this program is to couple experimental aqueous iodine volatilities to a fission product release model. Iodine partition coefficients, for inorganic iodine, have been measured during hydrolysis and radiolysis. The hydrolysis experiments have illustrated the importance of reaction time on iodine volatility. However, radiolysis effects can override hydrolysis in determining iodine volatility. In addition, silver metal in radiolysis samples can react to form silver iodide accompanied by a decrease in iodine volatility. Experimental data are now being coupled to an iodine transport and release model that was developed in the Federal Republic of Germany.

  5. Laser welding in space

    NASA Technical Reports Server (NTRS)

    Kaukler, W. F.; Workman, G. L.

    1991-01-01

    Autogenous welds in 304 stainless steel were performed by Nd-YAG laser heating in a simulated space environment. Simulation consists of welding on the NASA KC-135 aircraft to produce the microgravity and by containing the specimen in a vacuum chamber. Experimental results show that the microgravity welds are stronger, harder in the fusion zone, have deeper penetration and have a rougher surface rippling of the weld pool than one-g welds. To perform laser welding in space, a solar-pumped laser concept that significantly increases the laser conversion efficiency and makes welding viable despite the limited power availability of spacecraft is proposed.

  6. 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

    Guerra, Vasco; Kutasi, Kinga; Sa, Paulo A.

    2010-02-15

    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.

  7. Consequences of excess iodine

    PubMed Central

    Leung, Angela M.; Braverman, Lewis E.

    2014-01-01

    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

  8. 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

    Kutaev, Yu F; Mankevich, S K; Nosach, O Yu; Orlov, E P

    2007-07-31

    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)

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

    NASA Astrophysics Data System (ADS)

    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

    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.

  10. Atomic iodine production in a gas flow by decomposing methyl iodide in a dc glow discharge

    SciTech Connect

    Mikheyev, P A; Shepelenko, A A; Voronov, A I; Kupryaev, Nikolai V

    2002-01-31

    The production of atomic iodine for an oxygen - iodine laser is studied by decomposing methyl iodide in a dc glow discharge in a vortex gas flow. The concentration of iodine atoms in discharge products was measured from the atomic iodine absorption of the radiation of a single-frequency tunable diode laser at a wavelength of 1.315 {mu}m. Atomic iodine concentrations sufficient for the operation of an oxygen - iodine laser were obtained. The concentration of atomic iodine amounted to 3.6 x 10{sup 15} cm{sup -3} for a pressure of the carrying argon gas of 15 Torr. The discharge stabilisation by a vortex gas flow allowed the glow discharge to be sustained in a strongly electronegative halogen-containing gas mixture for pressures up to 20 Torr. (active media)

  11. Lasers '85; Proceedings of the Eighth International Conference, Las Vegas, NV, Dec. 2-6, 1985

    SciTech Connect

    Wang, C.P.

    1986-01-01

    The present conference on laser technology development encompasses issues in such areas as VUV and X-ray lasers; optical phase conjugation and nonlinear optics; laser applications in medicine; methods for optical processing; laser and nonlinear spectroscopy; ultrashort-pulse lasers and their applications; frequency selection in pulsed lasers; and interactions between laser beams, material surfaces, and material volumes. Also treated are laser applications in the Strategic Defense Initiative program, chemical laser design and performance, the lasing of biophysical materials, laser diagnostics in fluids and plasma, semiconductor laser diodes and arrays, solid state lasers, radiation- and solar-pumped lasers, laser cavities and propagation, remote sensing with lasers and fiber-optics, coupled resonators and diode lasers, industrial applications of lasers, excimer lasers, optoelectronics, CO/sub 2/ lasers, fiber-optic sensors, alexandrite lasers, free electron lasers, and IR and visible wavelength lasers.

  12. Iodine nutrition and breast feeding.

    PubMed

    Dorea, Jose G

    2002-01-01

    A survey of the databanks Medline and Web of science identified studies dealing with maternal and infant iodine nutrition during breast feeding. The iodine concentration of human milk varies widely due to maternal iodine intake. Mean breast milk iodine concentrations are reported as ranging from 5.4 to 2170 microg/L (median 62 microg/L) in worldwide studies. In the few studies that compared length of lactation, gestation length, and parity number, these factors did not significantly affect milk-iodine concentrations. In studies of maternal iodine deficiency, untreated goiter had no impact on breast milk iodine when compared with controls. Iodine in human milk responds quickly to dietary iodine intake, either supplemented or consumed in natural foods. Easily absorbable iodine from foods, supplemental sources, iodine-based medication or iodine-based antiseptic solutions used during parturition, is taken up by the maternal thyroid and mammary glands through the Na(+)/I(-) symporter system. This transmembrane carrier protein transports iodine against a high concentration gradient. Hormonal iodine in breast milk occurs mainly as T-4, but depending on maternal iodine intake, high concentrations of the inorganic form (iodide) are found. In less developed countries, where natural-food-iodine intake is low, adequate maternal iodine nutritional status depends exclusively on enforcement of food iodination. In industrialized countries, maternal iodine intake has increased as a function of increasing consumption of dairy products. The human infant is sensitive to maternal iodine nutrition during fetal development and later during breast feeding. Environmental factors, not directly related to maternal iodine intake, such as intake of selenium and organochlorine pollutants, can affect thyroid hormone homeostasis in breast-fed infants. In spite of low iodine concentrations found in milk of mothers consuming low-iodine natural foods, long lasting or even life-lasting benefits to the breast-fed infant are demonstrable. PMID:12530582

  13. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  14. COIL operation with iodine atoms generated in a glow discharge

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    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.

  15. Iodine generator for reclaimed water purification

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    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.

  16. Deep well solar pump

    SciTech Connect

    Vanek, J.

    1990-02-06

    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.

  17. Spaceborne Photonics Institute

    NASA Technical Reports Server (NTRS)

    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

    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.

  18. Relative quantum yield of I-asterisk(2P1/2) in the tunable laser UV photodissociation of i-C3F7I and n-C3F7I - Effect of temperature and exciplex emission

    NASA Technical Reports Server (NTRS)

    Smedley, J. E.; Leone, S. R.

    1983-01-01

    Wavelength-specific relative quantum yields of metastable I from pulsed laser photodissociation of i-C3F7I and n-C3F7I in the range 265-336 nm are determined by measuring the time-resolved infrared emission from the atomic I(P-2(1/2) P-2(3/2) transition. It is shown that although this yield appears to be unity from 265 to 298 nm, it decreases dramatically at longer wavelengths. Values are also reported for the enhancement of emission from metastable I due to exciplex formation at several temperatures. The exciplex formation emission increases linearly with parent gas pressure, but decreases with increasing temperature. Absorption spectra of i- and n-C3F7I between 303 and 497 K are presented, and the effect of temperature on the quantum yields at selected wavelengths greater than 300 nm, where increasing the temperature enhances the absorption considerably, are given. The results are discussed in regard to the development of solar-pumped iodine lasers.

  19. Prediction of I2P 1/2-->2P 3/2 transition lineshapes from 3-D, time dependent simulations of chemical oxygen-iodine laser (COIL) flowfields

    NASA Astrophysics Data System (ADS)

    Madden, Timothy J.

    2008-02-01

    The lineshape of the I2P 1/2-->2P 3/2 transition provides a means to ascertain a variety of useful information regarding the performance of the chemical oxygen-iodine laser (COIL). The value at the center of the lineshape, commonly referred to as the 'line center,' is proportional to the laser amplification on the I2P 1/2-->2P 3/2 transition. The infinite integral of the lineshape is proportional to the number density of the ground and excited states of atomic iodine in the gas, indicating the degree of I II dissociation. And the width of the lineshape indicates the amount of broadening of the transition, both due to collisional and Doppler shift effects. As the Doppler shift is proportional to velocity, the width of the transition can be used to estimate the degree of random molecular motion in the gas, expressed in macroscopic terms as temperature. A Doppler shift to the frequencies in the transition can also occur through the straight-line, bulk motion of the gas, and this can be used to examine the velocity field of the gas. However, the flow may experience rotation through the presence of eddies carried within the gas, and these too may contribute to the Doppler shift of the lineshape frequencies. Given that eddies by virtue of their positive and negative velocity components can induce positive and negative Doppler shift, the widening of the lineshape is similar to thermal motion which also includes positive and negative velocities. Thus, when interpreting transition lineshapes, if some account is not made for both thermal and rotational motion, the effect of either physical process will be over-estimated. The work discussed here is oriented toward examining the interplay between the gas dynamics and the lineshape of the I2P 1/2-->2P 3/2 transition, and in turn determine the ramifications for the use of spectroscopic lineshape based diagnostics and interpretation of their data. These efforts in turn are directly linked to efforts improve the understanding of the physical processes underlying chemical lasers, as excursions outside the traditional operational parameter space become increasingly necessary.

  20. Iodine Clock Reaction.

    ERIC Educational Resources Information Center

    Mitchell, Richard S.

    1996-01-01

    Describes a combination of solutions that can be used in the study of kinetics using the iodine clock reaction. The combination slows down degradation of the prepared solutions and can be used successfully for several weeks. (JRH)

  1. Iodine in diet

    MedlinePLUS

    ... daily recommendations by eating seafood, iodized salt, and plants grown in iodine-rich soil. When buying salt make sure it is labeled "iodized." The Food and Nutrition Board at the Institute of Medicine recommends the ...

  2. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  3. Radioactive Iodine (I-131) Therapy for Hyperthyroidism

    MedlinePLUS

    ... small dose of radioactive iodine I-131 (an isotope of iodine that emits radiation) is swallowed, it ... accelerating the metabolism. Radioactive iodine (I-131), an isotope of iodine that emits radiation, is used for ...

  4. Control of polarized iodine atom branching ratio in NaI photodissociation

    SciTech Connect

    Hosseini, Babak H.; Sadeghpour, H.R.; Balakrishnan, N.

    2005-02-01

    We report branching ratios between the ground and excited states of iodine atoms in the photodissociation of sodium iodide. We employ wave packet propagation techniques to study the optimal production of polarized iodine atoms and find experimentally realizable laser parameters to control the outcome. Application of a learning algorithm shows that the product branching can be controlled by suitably varying the time delay, the chirp, and the relative phase of the pump and control laser pulses. Periodic modulation of the polarized iodine atom branching ratio as a function of the delay between the firing of the two ultrashort laser pulses provides interesting insights into the photodissociation process.

  5. Iodine deficiency disorders in Europe.

    PubMed Central

    Delange, F.; Bürgi, H.

    1989-01-01

    Recent data on iodine excretion in the urine of adults, adolescents and newborns and on the iodine content of breast milk indicate a high prevalence of iodine deficiency (moderate in many cases and severe in a few) in many European countries. These cases may manifest as subclinical hypothyroidism in neonates and as goitre in adolescents and adults. Lack of iodine causes not only goitre, but also mental deficiency, hearing loss and other neurological impairments, and short stature due to thyroid insufficiency during fetal development and childhood. Although iodinated salt is available theoretically in most countries where it is needed, its quality and share of the market are often unsatisfactory. In many countries where only household salt is iodinated the iodine content has been set too low owing to an overestimation of household salt consumption. Governments are therefore urged to pass legislation and provide means for efficient iodination of salt wherever this is necessary. PMID:2670299

  6. Volatilization of iodine from vegetation

    NASA Astrophysics Data System (ADS)

    Amiro, B. D.; Johnston, F. L.

    Gaseous emissions of iodine were measured from bean plant foliage. A gamma-emitting iodine tracer, Na 125I, was taken up by the plants from a hydroponic growth medium and released to a cuvette atmosphere. The dynamics of the flux were studied using a flow-through gamma detector. The relationship between leaf radioactive tracer activity and growth-medium activity was linear, as was the relationship between the iodine flux and both leaf and growth-medium activity. Iodine flux and leaf conductance to water responded similarly to changes in light levels, suggesting that the stomata may partially control the flux. The flux was inhibited by aeration of the hydroponic growth medium, and we postulate that methylation causes the iodine flux. Iodine emissions from living vegetation probably contribute <0.1 % to the stable iodine concentration in the atmosphere above terrestrial areas. However, this pathway may be a direct route for radioactive iodine transport from contaminated soils to the atmosphere.

  7. Epidemiology of iodine deficiency: Salt iodisation and iodine status.

    PubMed

    Andersson, Maria; de Benoist, Bruno; Rogers, Lisa

    2010-02-01

    Universal salt iodisation (USI) and iodine supplementation are highly effective strategies for preventing and controlling iodine deficiency. USI is now implemented in nearly all countries worldwide, and two-thirds of the world's population is covered by iodised salt. The number of countries with iodine deficiency as a national public health problem has decreased from 110 in 1993 to 47 in 2007. Still one-third of households lack access to adequately iodised salt. Iodine deficiency remains a major threat to the health and development of populations around the world, particularly in children and pregnant women in low-income countries. Data on iodine status are available from 130 countries and approximately one-third of the global population is estimated to have a low iodine intake based on urinary iodine (UI) concentrations. Insufficient control of iodine fortification levels has led to excessive iodine intakes in 34 countries. The challenges ahead lie in ensuring higher coverage of adequately iodised salt, strengthening regular monitoring of salt iodisation and iodine status in the population, together with targeted interventions for vulnerable population groups. PMID:20172466

  8. Iodine Deficiency Disorders in the Iodine-Replete Environment

    PubMed Central

    Nyenwe, Ebenezer A.; Dagogo-Jack, Samuel

    2009-01-01

    Background Iodine deficiency disorders (IDD) constitute significant public health problems in parts of the world with poor iodine nutrition, but have been eradicated in North America and other regions. We herein report three cases of iodine deficiency disorders (IDD) which occurred in women living in iodine-replete environments. Methods The clinical presentation, biochemical findings, and radiological features of the patients were analyzed and presented in three case reports. The radiological features are illustrated in sonographic and scintigraphic images. A literature review and discussion which highlight the risk factors, pathogenesis, ancillary investigations and rational treatment of iodine deficiency goiter and hypothyroidism are provided. Results All of our three patients were young females, aged 24–38 years, who had goiter. Two of them presented with goitrous hypothyroidism. Radioactive iodine scintigraphy showed a characteristic finding of diffusely increased uptake (in the absence of clinical and biochemical evidence of hyperthyroidism). This scintigraphic pattern was found to be pathognomonic. Dietary iodine supplementation alone resulted in complete remission of IDD in the subjects, including the two patients with hypothyroidism. Conclusion IDD can occur in iodine replete-environments. A high index of suspicion is needed to recognize these cases. It is pertinent that the correct diagnosis be made to avoid unwarranted life-long thyroxine therapy in patients presenting with goiter and hypothyroidism, which is easily treatable with iodized salt. These cases underscore the need for considering iodine deficiency in the etiologic diagnosis of goiter and hypothyroidism, even in iodine sufficient regions. PMID:19155752

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

    NASA Astrophysics Data System (ADS)

    Zhou, Junbo; Hao, Shan; Gao, Liping

    2014-04-01

    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 μg 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.

  10. [Allergy to iodinated drugs and to foods rich in iodine: Iodine is not the allergenic determinant].

    PubMed

    Dewachter, Pascale; Mouton-Faivre, Claudie

    2015-11-01

    "Iodine allergy" does not exist. The concept of "iodine allergy" should be abandoned since it may result in inappropriate measures such as drug, food or environmental eviction. Immediate or non-immediate allergic hypersensitivity to iodinated contrast media is not infrequent. The corresponding allergens have not been identified. Iodine is not involved. Immediate or non-immediate allergic hypersensitivity to povidone iodine is rare. The corresponding allergen is povidone in case of immediate hypersensitivity while nonoxynol might be involved during non-immediate hypersensitivity. Seafood allergens belong to a group of muscle proteins. Immediate drug hypersensitivity or food hypersensitivity is assessed by immediate-reading skin tests while non-immediate drug hypersensitivity is investigated by delayed-reading skin testing. Combined histamine and tryptase measurement is invaluable during the diagnostic approach of immediate hypersensitivity. Other biological tests are being evaluated. Allergic hypersensitivity to iodinated contrast agents does not contraindicate the use of other iodinated drugs. PMID:26387623

  11. High-performance iodine fiber frequency standard.

    PubMed

    Lurie, Anna; Baynes, Fred N; Anstie, James D; Light, Philip S; Benabid, Fetah; Stace, Thomas M; Luiten, Andre N

    2011-12-15

    We have constructed a compact and robust optical frequency standard based around iodine vapor loaded into the core of a hollow-core photonic crystal fiber (HC-PCF). A 532 nm laser was frequency locked to one hyperfine component of the R(56) 32-0 (127)I(2) transition using modulation transfer spectroscopy. The stabilized laser demonstrated a frequency stability of 2.3×10(-12) at 1 s, almost an order of magnitude better than previously reported for a laser stabilized to a gas-filled HC-PCF. This limit is set by the shot noise in the detection system. We present a discussion of the current limitations to the performance and a route to improve the performance by more than an order of magnitude. PMID:22179880

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

    NASA Technical Reports Server (NTRS)

    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

    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.

  13. Hermetic optical-fiber iodine frequency standard.

    PubMed

    Light, Philip S; Anstie, James D; Benabid, Fetah; Luiten, Andre N

    2015-06-15

    We have built an optical-frequency standard based on interrogating iodine vapor that has been trapped within the hollow core of a hermetically sealed kagome-lattice photonic crystal fiber. A frequency-doubled Nd:YAG laser locked to a hyperfine component of the P(142)37-0 I2127 transition using modulation transfer spectroscopy shows a frequency stability of 3×10(-11) at 100 s. We discuss the impediments in integrating this all-fiber standard into a fully optical-fiber-based system, and suggest approaches that could improve performance of the frequency standard substantially. PMID:26076241

  14. Iodine removal using silver mordenite

    SciTech Connect

    Bridges, N.

    1985-07-18

    Iodine is released to the off-gas during uranium dissolution in the annular dissolvers in F-Canyon. The iodine is currently removed by reaction with silver nitrate coated Berl saddles. Iodine removal has been adequate but the average life of the iodine reactor bed has been less than expected. Failure of the iodine reactor is usually indicated by a high reactor differential pressure. Pluggage of the reactor is due primarily to entrainment of dissolver solution into the reactor and degradation of the Berl saddles. In addition to frequent replacements, it has become more difficult to obtain Berl saddles coated with silver nitrate at SRP. This TA authorizes the use of silver mordenite for iodine adsorption instead of the Berl saddles.

  15. Iodine addition using triiodide solutions

    NASA Technical Reports Server (NTRS)

    Rutz, Jeffrey A.; Muckle, Susan V.; Sauer, Richard L.

    1992-01-01

    The study develops: a triiodide solution for use in preparing ground service equipment (GSE) water for Shuttle support, an iodine dissolution method that is reliable and requires minimal time and effort to prepare, and an iodine dissolution agent with a minimal concentration of sodium salt. Sodium iodide and hydriodic acid were both found to dissolve iodine to attain the desired GSE iodine concentrations of 7.5 +/- 2.5 mg/L and 25 +/- 5 mg/L. The 1.75:1 and 2:1 sodium iodide solutions produced higher iodine recoveries than the 1.2:1 hydriodic acid solution. A two-hour preparation time is required for the three sodium iodide solutions. The 1.2:1 hydriodic acid solution can be prepared in less than 5 min. Two sodium iodide stock solutions (2.5:1 and 2:1) were found to dissolve iodine without undergoing precipitation.

  16. Iodine dynamics in soils

    NASA Astrophysics Data System (ADS)

    Shetaya, W. H.; Young, S. D.; Watts, M. J.; Ander, E. L.; Bailey, E. H.

    2012-01-01

    We investigated changes in iodine (129I) solubility and speciation in nine soils with contrasting properties (pH, Fe/Mn oxides, organic carbon and iodine contents), incubated for nine months at 10 and 20 C. The rate of 129I sorption was greater in soils with large organic carbon contents (%SOC), low pH and at higher temperatures. Loss of iodide (I-) from solution was extremely rapid, apparently reaching completion over minutes-hours; iodate (IO3-) loss from solution was slower, typically occurring over hours-days. In all soils an apparently instantaneous sorption reaction was followed by a slower sorption process for IO3-. For iodide a faster overall reaction meant that discrimination between the two processes was less clear. Instantaneous sorption of IO3- was greater in soils with high Fe/Mn oxide content, low pH and low SOC content, whereas the rate of time-dependent sorption was greatest in soils with higher SOC contents. Phosphate extraction (0.15 M KH2PO4) of soils, ?100 h after 129I spike addition, indicated that concentrations of sorbed inorganic iodine (129I) were very low in all soils suggesting that inorganic iodine adsorption onto oxide phases has little impact on the rate of iodine assimilation into humus. Transformation of dissolved inorganic 129IO3- and 129I- to sorbed organic forms was modelled using a range of reaction- and diffusion-based approaches. Irreversible and reversible first order kinetic models, and a spherical diffusion model, adequately described the kinetics of both IO3- and I- loss from the soil solution but required inclusion of a distribution coefficient (kd) to allow for instantaneous adsorption. A spherical diffusion model was also collectively parameterised for all the soils studied by using pH, soil organic carbon concentration and combined Fe + Mn oxide content as determinants of the model parameters (kd and D/r2). The kinetic model parameters were not directly related to a single soil parameter; inclusion of pH, SOC, oxide content and temperature was necessary to describe the observed behaviour. From the temperature-dependence of the sorption data the activation energy (Ea) for 129IO3- transformation to organic forms was estimated to be ?43 kJ mol-1. The Ea value was independent of %SOC and was consistent with a reaction mechanism slower than pore diffusion or physical adsorption, but faster than most surface reactions.

  17. Iodine neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Ahmed, Kazi Fariduddin

    A new technique, Iodine Neutron Capture Therapy (INCT) is proposed to treat hyperthyroidism in people. Present thyroid therapies, surgical removal and 131I treatment, result in hypothyroidism and, for 131I, involve protracted treatment times and excessive whole-body radiation doses. The new technique involves using a low energy neutron beam to convert a fraction of the natural iodine stored in the thyroid to radioactive 128I, which has a 24-minute half-life and decays by emitting 2.12-MeV beta particles. The beta particles are absorbed in and damage some thyroid tissue cells and consequently reduce the production and release of thyroid hormones to the blood stream. Treatment times and whole-body radiation doses are thus reduced substantially. This dissertation addresses the first of the several steps needed to obtain medical profession acceptance and regulatory approval to implement this therapy. As with other such programs, initial feasibility is established by performing experiments on suitable small mammals. Laboratory rats were used and their thyroids were exposed to the beta particles coming from small encapsulated amounts of 128I. Masses of 89.0 mg reagent-grade elemental iodine crystals have been activated in the ISU AGN-201 reactor to provide 0.033 mBq of 128I. This activity delivers 0.2 Gy to the thyroid gland of 300-g male rats having fresh thyroid tissue masses of ˜20 mg. Larger iodine masses are used to provide greater doses. The activated iodine is encapsulated to form a thin (0.16 cm 2/mg) patch that is then applied directly to the surgically exposed thyroid of an anesthetized rat. Direct neutron irradiation of a rat's thyroid was not possible due to its small size. Direct in-vivo exposure of the thyroid of the rat to the emitted radiation from 128I is allowed to continue for 2.5 hours (6 half-lives). Pre- and post-exposure blood samples are taken to quantify thyroid hormone levels. The serum T4 concentration is measured by radioimmunoassay at different times after exposure as an indicator of thyroid function. Cell damage is assessed by postmortem histopathologic examination. The intent of this endeavor is to relate radiation dose, T4 concentration in the blood stream and cellular damage. This information will help better understand the dose response relationship of thyroid cells exposed to ionizing radiation.

  18. Beamed laser power in support of near-earth missions

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.; Schuster, Gregory L.; Weaver, Willard; Humes, Donald H.

    1989-01-01

    It was found that solar-pumped laser-beamed power is lighter than photovoltaic for power requirements of 150 KWe and above, and is competitive with combined photovoltaic/solar-dynamic over the entire power range investigated. A space station supported by laser-beamed power can be a lower-g facility (reduced drag) than with PV or PV + SD power; has greater freedom of orientation (small receiver moves rather than large arrays or concentrators); and requires less structure (arrays, alpha joints, booms) permitting easier control and fewer vibrational modes. Laser power beaming offers a revolutionary concept for planning designing, and powering large orbiting spacecraft.

  19. Criteria for the evaluation of laser solar energy converter systems

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1985-01-01

    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.

  20. Global Modelling of Tropospheric Iodine

    NASA Astrophysics Data System (ADS)

    Chipperfield, Martyn; Breider, Tom; Mantle, Hannah; Hossaini, Ryan; Mann, Graham; Plane, John

    2013-04-01

    Halogen species play an important role in tropospheric chemistry. Iodine is believed to enhance catalytic ozone loss (acting synergistically with bromine) and can lead to the formation of new particles. Recent observations have increased our knowledge on the role of iodine but key processes need to be tested and quantified by inclusion in numerical models. We describe the development of an iodine chemistry scheme within the TOMCAT global 3-D chemical transport model (CTM). The existing model contained a detailed tropospheric chemistry scheme (including bromine) along with the GLOMAP aerosol scheme. The new iodine scheme contains a treatment of organic source gas emissions along with a simple parameterisation of I2 emission from the ocean based on ozone deposition. The model has been integrated at a horizontal resolution of 2.8 x 2.8 degrees and is forced by ECMWF analyses for annual integrations. We have used the model, coupled to a detailed size-resolved aerosol microphysics module, to study iodine chemistry in the troposphere. The model reproduces observed CH3I distributions. Mixing ratios of other organic iodine compounds are small due to shorter lifetimes. Our simulations show the observed IO at Cape Verde in the Tropical East Atlantic cannot be reproduced with the measured organic iodine source fluxes alone and requires an additional iodine source, in agreement with other studies. Our simulations show iodine chemistry significantly perturbs tropospheric ozone. Emissions of organic iodine species result in a 17 Tg reduction in the troposphere ozone burden. The dominant iodine-driven ozone sink is the reaction of HO2 + IO (175 Tg O3 yr-1).

  1. Iodine Atoms Structured in (SN)x

    NASA Astrophysics Data System (ADS)

    Isoda, Seiji; Kawaguchi, Akiyoshi; Uemura, Akio; Katayama, Ken-ichi

    1985-05-01

    Electron diffraction pattern of iodinated (SN)x shows that iodine atoms are structured as a chain along the molecular axis of (SN)x. High resolution electron micrograph and its optical transform show that the crystalline lattice is severely distorted by iodination, but the (\\bar{1}02) plane is comparatively stable for iodine invasion. Iodine atoms are considered to be settled on the (\\bar{1}02) plane, where iodine atoms are structured as iodine chains and the two iodine chains tend to pair.

  2. Hypothyroidism following iodine-131 therapy

    SciTech Connect

    Hays, M.T.

    1982-02-01

    A teaching editorial dealing with the hypothyroidism side effect of Iodine-131 radiotherapy is presented. The author reviews two articles in this issue of the Journal of Nuclear Medicine on the subject, discusses Graves' disease, Iodine 125 radiotherapy, and the patient-physician relationship when dealing with the problem. (JMT)

  3. Iodine-Catalyzed Polysaccharide Esterification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A review is provided of the recent reports to use iodine-catalyzed esterification reaction to produce esters from polysaccharides. The process entails reaction of the polysaccharide with an acid anhydride in the presence of a catalytic level of iodine, and in the absence of additional solvents. T...

  4. Resonant Raman scattering of polymeric sulfur nitride modified by iodine

    NASA Astrophysics Data System (ADS)

    Tubino, R.; Piseri, L.; Carcano, G.; Pollini, I.

    1980-04-01

    Resonance Raman spectra of (SNI y) x crystals have been measured at 150 K. The energies of the principal Raman lines of the chromophore (109 and 154 cm -1) and their intensity behaviour with exciting laser frequency are consistent with the formation of a charge-transfer complex in which iodine enters the interfiber regions of the (SN) x lattice as I 5- or I 3- linked to distorted I 2 units. This structural model is supported by comparison of these Raman data with the excitation profiles of the chromophoric group in starch-iodine and α-cyclodextrine-iodine complexes. Possible mechanisms for the conductivity increase on the basis of the proposed charge transfer model are also discussed.

  5. Iodine Tagging Velocimetry in a Mach 10 Wake

    NASA Technical Reports Server (NTRS)

    Balla, Robert Jeffrey

    2013-01-01

    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%.

  6. A high dietary iodine increases thyroid iodine stores and iodine concentration in blood serum but has little effect on muscle iodine content in pigs.

    PubMed

    Schne, F; Zimmermann, Christina; Quanz, G; Richter, G; Leiterer, M

    2006-02-01

    There is still iodine deficiency in many populations, which justifies efforts to increase this trace element in food such as milk, eggs and meat by fortifying compound animal feeds with extra iodine. The iodine requirement of growing pigs is in the order of 100-200?g/kg feed (as a supplement) and the effects of this dosage range or higher on pork iodine concentration should be determined including the action of relevant iodine antagonists in feed, e.g., rapeseed. In three experiments on a total of 208 pigs [Pietrain(LandraceLarge White)] the iodine concentration of meat (m. longissimus) - 71 samples -, blood serum - 100 samples - and of the thyroid - 100 samples - was analysed by intracoupled plasma-MS. In Experiment 1, 410 pigs received diets without or with rapeseed cake (0 and 3.2mmol glucosinolates/kg diet) either with 125 or with 250?g iodine/kg. In Experiment 2, the three groups with 46 pigs each were fed high iodine diets (1200?g supplementary iodine/kg) without or with 100 or 150g solvent extracted rapeseed meal/kg diet (0; 0.8 and 1.2mmol glucosinolates/kg). In Experiment 3, 310 pigs received either 600?g iodine/kg feed (1) or the 5-fold dosage (600+2400?g iodine/kg diet) administered 7 days (2) or 18 days (3) before slaughtering. The group means of pork iodine content were in the relatively small range from 3 to 16?g/kg, which contrasted to the enormously varying dosage range from 125 to 3000?g iodine/kg diet. There was a certain iodine dosage effect in Experiment 3 when - in comparison to the control - a 3-fold higher meat iodine concentration resulted from a 5-fold higher diet iodine concentration. In Experiment 1 with the low iodine offer, rapeseed cake with glucosinolates decreased the serum iodine level whereas in Experiment 2 this did not happen due to higher iodine fed and lower glucosinolates exposure. The thyroid iodine reflected the dietary iodine better than blood serum iodine and the serum better than muscle. However, in Experiment 2, 1200?g iodine/kg diet produced only half the serum iodine concentration than half as much dietary iodine in Experiment 3 (600?g iodine/kg diet), which may result from rapid elimination of blood iodine and a higher urinary excretion by longer duration of feed withdrawal before blood sampling. The muscle of pigs has to be classified as a low iodine food. Thus, there are no possibilities to concentrate this trace element reproducibly in amounts relevant for human nutrition in pork. PMID:22061566

  7. Regioselective, Molecular Iodine-Mediated C3 Iodination of Quinolines.

    PubMed

    Sun, Kai; Lv, Yunhe; Wang, Junjie; Sun, Jingjing; Liu, Lulu; Jia, Mingyang; Liu, Xin; Li, Zhenduo; Wang, Xin

    2015-09-18

    A novel and convenient method has been developed for the regioselective iodination of quinolines at their C3 position under metal-free conditions. Iodinated quinolines, which are popular building blocks in organic and medicinal chemistry, can be prepared in gram quantities and good yields using this method and further derivatized to give increasingly complex compounds. Preliminary mechanistic studies have shown that this reaction most likely occurs via a radical intermediate. PMID:26235562

  8. Iodine deficiency and neonatal hypothyroidism*

    PubMed Central

    Kochupillai, N.; Pandav, C. S.; Godbole, M. M.; Mehta, M.; Ahuja, M. M. S.

    1986-01-01

    The incidence of neonatal hypothyroidism, as reflected in cord-blood thyroxine and thyrotropin levels, varied from 0.6% to 13.3% in iodine-deficient and normal regions of India (selected districts of Uttar Pradesh and Kerala and the city of Delhi), depending on the degree of environmental iodine deficiency. In populations with a high incidence of neonatal hypothyroidism, an increased prevalence of nerve deafness and a shift to the left in the distribution of IQ scores (towards lower scores) have been demonstrated. These indications of mild brain damage suggest that nutritional iodine deficiency can present in other ways than goitre or cretinism. Determination of the incidence of neonatal hypothyroidism using dried cord-blood spot screening appears to be the most useful and reliable method to assess the risk of brain damage in iodine-deficient areas. PMID:3490923

  9. Immobilization of iodine in concrete

    DOEpatents

    Clark, Walter E.; Thompson, Clarence T.

    1977-04-12

    A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3-20 wt. % iodine as Ba(IO.sub.3).sub.2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO.sub.3).sub.2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. BACKGROUND OF THE INVENTION This invention was made in the course of, or under a contract with the Energy Research and Development Administration. It relates in general to reactor waste solidification and more specifically to the immobilization of fission product radioactive iodine recovered from irradiated nuclear fuel for underground storage.

  10. Lithium-iodine pacemaker cell

    SciTech Connect

    Schneider, A.A.; Snyder, S.E.; DeVan, T.; Harney, M.J.; Harney, D.E.

    1980-01-01

    The lithium-iodine pacemaker cell is described as supplied by several manufacturers. The features of each design are discussed along with their effect on energy density, self-discharge and shape of the discharge curve. Differences in performance characteristics are related to morphology of the lithium iodine electrolyte and to the form of the cathode. A new, high-drain cell is mentioned which can supply 60 /mu/a/cm/sup 2/. 10 refs.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

    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.

  12. PRODUCTION OF RADIOACTIVE IODINE.

    SciTech Connect

    SCHLYER,D.J.

    2001-08-08

    Probably the most widely used cyclotron produced radiohalogen is I-123. It has gradually replaced I-131 as the isotope of choice for diagnostic radiopharmaceuticals containing radioiodine. It gives a much lower radiation dose to the patient and the gamma ray energy of 159 keV is ideally suited for use in a gamma camera. The gamma ray will penetrate tissue very effectively without excessive radiation dose. For this reason, it has in many instances replaced the reactor produced iodine-131 (Lambrecht and Wolf 1973). A great number of radiopharmaceuticals have been labeled using I-123 and the number is increasing. One of the most promising uses of I-123 is in the imaging of monoclonal antibodies to localize and visualize tumors. However, preclinical and clinical experiences with radiolabeled antibodies have not realized the expectations regarding specificity and sensitivity of tumor localization with these agents. It appears that much of the administered activity is not associated with the tumor site and only a small fraction actually accumulates there. Work continues in this area and tumor-associated antigens can be targets for specific antibody reagents.

  13. Development of an online method for quantification of maritime molecular iodine and other gaseous iodine containing inorganic compounds

    NASA Astrophysics Data System (ADS)

    Götz, Sven; Hoffmann, Thorsten

    2014-05-01

    The atmospheric chemistry of iodine is important in multiple ways. The focus lies on the ability to influence the oxidizing capacity of the atmosphere, i.e. by destruction of ozone, and the formation of iodine oxide particles (IOP), i.e. the influence on condensation nuclei (CCN). Using a variation of techniques, like differential optical absorption spectroscopy (DOAS), laser-induced fluorescence (LIF), inductively coupled plasma mass spectrometry (ICP-MS) and atmospheric pressure chemical ionization with tandem mass spectrometry (APCI-MS/MS), the reactive iodine species of atomic iodine (I), molecular iodine (I2), iodine monoxide (IO) and iodine dioxide (OIO) have all been detected in the atmosphere from Antarctica to the equatorial marine boundary layer (MBL). In the past few years there have been active research on IO, especially after revealing significant levels in open ocean measurements, OIO and higher iodine oxides. In addition to atmospheric measurements, significant developments in laboratory kinetics, photochemistry and heterogeneous chemistry of iodine species have been accomplished. [1] Here we introduce an online-method for detecting gaseous molecular iodine and other gaseous iodine-containing inorganic compounds such as HOI, which is a further development of the technique used by Carpenter et al. [2]. The method is based on selective photolytic dissociation of the analytes, followed by oxidization and particle formation of the iodine compounds. The particles are than size-segregated and detected by a scanning mobility particle sizer (SMPS) system. Initial IOP forming is performed in a reaction chamber providing specific wavelengths according to corresponding bond dissociation thresholds. Atmospheric samples can also be pre concentrated by diffusion denuder (with α Cyclodextrin modified and immobilised silica coating) [3-5] and afterwards released by thermodesorption. First attempts of quantification are carried out by external calibration using an iodine diffusion source and aqueous solution of hypoiodic acid [6]. Preliminary results will be shown. [1] Saiz-Lopez, A.; Plane, J. M.C.; Baker, A. R.; Carpenter, L. J., von Glasow, R.; Gómez Martín, J. C.; McFiggans, G.; Saunders, R. W.; Chem. Rev., 2012, 112, 1773 1804 [2] Carpenter, L. J.; MacDonald, S. M.; Shaw, M. D.; Kumar, R.; Saunders, R.W.; Parthipan, R.; Wilson, J.; Plane, J. M. C.; Nature Geoscience, 2013, 6, 108 111 [3] Huang, R. J.; Hoffmann, T.; Anal. Chemistry, 2009, 81, 1777 1783 [4] Liu, M.; Da, S. L.; Feng, Y. Q.; Li, L. S.; Anal. Chim. Acta, 2005, 533, 89 95. [5] Tsai, M.-Y.; Hsu, C. C.; Chen, P. H.; Lin, C. S.; Chen, A.; Surface Science, 2011, 257, 8640-8646. [6] Muntean, N.; Thuy, L. B.; Kály-Kullai, K.; Wittmann, M.; Noszticzius, Z.; Onel, L.; Furrow, S. D.; J. Phys. Chem. A, 2012, 116, 6630 6642

  14. Frequency locking to the center of a 532 nm iodine absorption line by using stimulated brillouin scattering from a single-mode fiber.

    PubMed

    Eloranta, E W; Razenkov, I A

    2006-03-01

    A simple method for frequency locking a frequency-doubled Nd:YAG laser to the center of line 1109 of the iodine absorption spectrum is described. The 31.6 GHz frequency shift provided by stimulated-Brillouin scattering from a single-mode silica fiber provides a probe signal that lies on the edge of line 1105 of the iodine spectrum. We adjust the frequency of the laser to maintain the transmission of a 5 cm iodine absorption cell at a value that places the unshifted laser line in the center of line 1109. PMID:16570410

  15. Iodine, thyroid autoimmunity and cancer.

    PubMed

    Fiore, Emilio; Latrofa, Francesco; Vitti, Paolo

    2015-03-01

    This review focuses on two different topics: (a) iodine and autoimmune thyroid disease (AITD) and (b) AITD and papillary thyroid carcinoma (PTC). Iodine intake modifies the expression of thyroid diseases and has been associated with induction of AITD. Thyroglobulin (Tg) is an important target in iodine-induced autoimmune response due to post-translational modifications of iodinated Tg, as suggested in animal models. We have shown that the unmasking of a cryptic epitope on Tg contributes to iodine-induced thyroid autoimmunity in humans. The relationship between AITD and PTC has been suggested in many studies. The presence of two different mechanisms has been hypothesized, one typical of AITD and the other of an immune reaction to PTC. We have shown that in AITD, the pattern of Tg recognition by anti-Tg antibodies (TgAb) is 'restricted' to the immunodominant regions of Tg, while in patients with non-AITD, such as nodular goiter and PTC devoid of thyroid lymphocytic infiltration at histology, TgAb show a less restricted epitopic pattern and bind also to other regions of Tg. Thyroid function may also affect the frequency of PTC, the risk of cancer increasing with serum TSH levels. We have shown that this mechanism, rather than thyroiditis per se, plays a major role in the association of PTC with Hashimoto's thyroiditis, as a consequence of the autoimmune process leading to a progressive increase of serum TSH in these patients. PMID:25960959

  16. Enabling lunar and space missions by laser power transmission

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Nealy, J. E.; Humes, D. H.; Meador, W. E.

    1992-01-01

    Applications are proposed for laser power transmission on the Moon. A solar-pumped laser in lunar orbit would beam power to the lunar surface for conversion into either electricity or propulsion needs. For example, lunar rovers could be much more flexible and lighter than rovers using other primary power sources. Also, laser power could be absorbed by lunar soil to create a hard glassy surface for dust-free roadways and launch pads. Laser power could also be used to power small lunar rockets or orbital transfer vehicles, and finally, photovoltaic laser converters could power remote excavation vehicles and human habitats. Laser power transmission is shown to be a highly flexible, enabling primary power source for lunar missions.

  17. The Absorption Spectrum of Iodine Vapour

    ERIC Educational Resources Information Center

    Tetlow, K. S.

    1972-01-01

    A laboratory experiment is described which presents some molecular parameters of iodine molecule by studying iodine spectrum. Points out this experiment can be conducted by sixth form students in high school laboratories. (PS)

  18. Towards graphene iodide: iodination of graphite oxide

    NASA Astrophysics Data System (ADS)

    imek, Petr; Klmov, Kate?ina; Sedmidubsk, David; Jankovsk, Ond?ej; Pumera, Martin; Sofer, Zden?k

    2014-11-01

    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

  19. Perchlorate, iodine and the thyroid

    PubMed Central

    Leung, Angela M.; Pearce, Elizabeth N.; Braverman, Lewis E.

    2014-01-01

    In pharmacologic doses, perchlorate inhibits thyroidal iodine uptake and subsequently decreases thyroid hormone production. Although pharmacologic doses may be used in the treatment of hyperthyroidism, recent literature has focussed on the detection of low levels of perchlorate in the environment, groundwater and foodstuffs and their potential adverse effects on human thyroid function. This is of particular concern to the developing foetus and infant, whose normal neurodevelopment depends on adequate iodine intake for the production of thyroid hormones. Further research is needed to clarify the potential health effects of low-level chronic environmental perchlorate exposure. The health impact of environmental perchlorate may be dependent upon adequate iodine intake and should be interpreted in combination with other environmental exposures that are also potential thyroidal endocrine disruptors. PMID:20172477

  20. Mineral resource of the month: iodine

    USGS Publications Warehouse

    Polyak, Désirée E.

    2009-01-01

    The article focuses on iodine, its benefits and adverse effects, and its production and consumption. It states that iodine is essential to humans for it produces thyroid hormones to nourish thyroid glands but excessive intake could cause goiter, hyperthyroidism or hypothyroidism. U.S. laws require salt iodization to help prevent diseases. Chile and Japan are the world's leading iodine producer while in the U.S. iodine is mined from deep well brines in northern Oklahoma.

  1. Sublimation of Iodine at Various Pressures

    ERIC Educational Resources Information Center

    Leenson, Ilya A.

    2005-01-01

    Various phenomena that are observed in the process of heating solid iodine in closed vessels at different pressures and temperatures are described. When solid iodine is heated in an evacuated ampoule where the pressure is less than 10(super -3), no noticeable color appears and immediate condensation of tiny iodine crystals is visible higher up on

  2. Sublimation of Iodine at Various Pressures

    ERIC Educational Resources Information Center

    Leenson, Ilya A.

    2005-01-01

    Various phenomena that are observed in the process of heating solid iodine in closed vessels at different pressures and temperatures are described. When solid iodine is heated in an evacuated ampoule where the pressure is less than 10(super -3), no noticeable color appears and immediate condensation of tiny iodine crystals is visible higher up on…

  3. 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...

  4. Laser Welding in Space

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Kaukler, William F.

    1989-01-01

    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.

  5. Advanced prototype automated iodine monitor system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    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.

  6. Synthesis and characterization of iodinated polystyrene

    SciTech Connect

    Overturf, G.E. III; Buckley, S.R.; Cook, R.C.

    1992-11-19

    A method to selectively iodinate monodisperse 100,000 molecular weight polystyrene has been developed by performing an electrophilic aromatic substitution on the polymer in which the degree of iodination is limited stoichiometrically. The iodination electrophile used was trifluoroacetyl hypoidite which yielded polymers with up to 1.4 atom % iodine (i.e substitution of a single iodine atom on 20% of the rings) under mild conditions with virtually no degradation in the polydispersity of polystyrene. This report documents the work performed in the areas of synthesis and polymer characterization. 29 figs, 9 refs, 9 tabs.

  7. An iodine-based frequency reference for space applications

    NASA Astrophysics Data System (ADS)

    Schuldt, Thilo; Johann, Ulrich; Doeringshoff, Klaus; Kovalchuk, Evgeny; Peters, Achim; Braxmaier, Claus; Pahl, Julia; Stuehler, Johannes; Franz, Matthias

    We present the development of an iodine-based frequency reference for future potential applications in space, including the gravitational wave detector LISA/eLISA (Laser Interferometer Space Antenna), the mini SpaceTime Asymmetry Research (mSTAR) program, the aperture-synthesis telescope Darwin and the GRACE (Gravity Recovery and Climate Experiment) follow on mission/NGGM (Next Generation Gravity Mission) exploring Earth's gravity. Based on a state-of-the-art laboratory iodine frequency reference, setups on elegant breadboard (EBB) and engineering model (EM) level were realized, taking into account specific design criteria for space compatibility such as compactness and robustness. Both setups employ modulation transfer spectroscopy (MTS) in combination with balanced detection. They use a baseplate made of glass material in combination with a dedicated easy-to-handle assembly-integration technology (adhesive bonding) ensuring high pointing stability of the two counter-propagating laser beams in the iodine cell and therefore high long-term stability. The EBB setup utilizes a commercial off-the-shelf 30 cm long iodine cell in triple-pass configuration, the EM setup a specifically designed and manufactured compact iodine cell made of fused silica in a nine-pass configuration with a specific robust cold finger design. Both setups were characterized in beat measurements with a ULE cavity setup. Similar frequency stabilities of about 1*10 (-14) at an integration time of 1 s and below 5*10 (-15) at integration times between 10 s and 100 s were demonstrated. These values are comparable to the currently best laboratory setups. The EM setup was further subjected to environmental testing including thermal cycling and vibrational testing. Financial support by the German Space Agency DLR with funds provided by the Federal Ministry of Economics and Technology (BMWi) under grant numbers 50 QT 1102 and 50 QT 1201 is highly appreciated. The authors thank Jan Hrabina and Josef Lazar from the Institute of Scientific Instruments of the Academy of Sciences of the Czech Republic, Brno, for fruitful discussions on the realization of the multipass iodine cell.

  8. Towards graphene iodide: iodination of graphite oxide.

    PubMed

    imek, Petr; Klmov, Kate?ina; Sedmidubsk, David; Jankovsk, Ond?ej; Pumera, Martin; Sofer, Zden?k

    2015-01-01

    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. PMID:25407247

  9. An innovative approach for iodine supplementation using iodine-rich phytogenic food.

    PubMed

    Weng, Huan-Xin; Liu, Hui-Ping; Li, De-Wang; Ye, Mingli; Pan, Lehua; Xia, Tian-Hong

    2014-08-01

    Iodine, as one of the essential trace elements for human body, is very important for the proper function of thyroid gland. In some regions, people are still suffering from iodine deficiency disorder(IDD). How to provide an effective and cost-efficient iodine supplementation has been a public health issue for many countries. In this review, a novel iodine supplementation approach is introduced. Different from traditional iodine salt supplement, this approach innovatively uses cultivated iodine-rich phytogenic food as the supplement. These foods are cultivated using alga-based organic iodine fertilizer. The feasibility, mechanics of iodine absorption of plants from soil and the bioavailability of iodine-rich phytogenic food are further discussed. PMID:24504625

  10. Mechanism of iodine uptake by cabbage: effects of iodine species and where it is stored.

    PubMed

    Weng, Huan-Xin; Hong, Chun-Lai; Yan, Ai-Lan; Pan, Le-Hua; Qin, Ya-Chao; Bao, Lü-Ting; Xie, Ling-Li

    2008-10-01

    Iodine-enhanced vegetable has been proven to be an effective way to reduce iodine deficiency disorders in many regions. However, the knowledge about what mechanisms control plant uptake of iodine and where iodine is stored in plants is still very limited. A series of controlled experiments, including solution culture, pot planting, and field experiments were carried out to investigate the uptake mechanism of iodine in different forms. A new methodology for observing the iodine distribution within the plant tissues, based on AgI precipitation reaction and transmission electron microscope techniques, has been developed and successfully applied to Chinese cabbage. Results show that iodine uptake by Chinese cabbage was more effective when iodine was in the form of IO(3) (-) than in the form of I(-) if the concentration was low (<0.5 mg L(-1)), but the trend was opposite if iodine concentration was 0.5 mg L(-1) or higher. The uptake was more sensitive to metabolism inhibitor in lower concentration of iodine, which implies that the uptake mechanism transits from active to passive as the iodine concentration increases, especially when the iodine is in the form of IO(3) (-). The inorganic iodine fertilizer provided a quicker supply for plant uptake, but the higher level of iodine was toxic to plant growth. The organic iodine fertilizer (seaweed composite) provided a more sustainable iodine supply for plants. Most of the iodine uptake by the cabbage is intercepted and stored in the fibrins in the root while the iodine that is transported to the above-ground portion (shoots and leaves) is selectively stored in the chloroplasts. PMID:18521548

  11. Hypervalent Iodine Iodinative Decarboxylation Of Cubyl And Homocubyl Carboxylic Acids

    NASA Astrophysics Data System (ADS)

    Moriarty, Robert M.; Khosrowshahi, Jaffar S.; Dalecki, Tomasz

    1988-05-01

    The hypervalent iodine oxidative decarboxylation of homocubyl and cubyl mono- and di-carboxylic acids is reported; the carboxylic acid is treated with PhI(OAc)2CC14-I2 under irradiation conditions and 80-90% of the derived iodo compound is obtained. Systematic functionalization of cubane is an important synthetic goal. The two main methods of cubane synthesis involve sequential Favorskii ring contractions to yield first a homocubyl carboxylic acid, and theh after a second Favorskii reaction, a 1,41,2 or 1,33 cubyl dicarboxylic acid. As a consequence of this synthetic procedure the carboxy group is a logical starting functionality for subsequent synthetic transformation in the cubyl ring system. The carboxy group has been converted ,into a nitro group in the synthesis of 1,4-dinitrocubane4 and halogenodecarboxylation has been effected.596 In a basically different approach Eaton et al., used ortho-lithiation of the der td carboxamide etc a site for ortho-iodination.7 Introduction of an iodo group onto the cubyl system is especially desirable because hypervalent iodine synthetic methodology may be employed in order to effect displacement reactions. This scheme has been successfully applied by Eaton et al.8 in tim cubyl system for R-IC12+ R-C1 R-I(OAC)2+ R-OAc where R=1- iodo-2-N,N-di-isopropylcarbox-amido-5-methylcubane.

  12. Biologically available iodine in goitrogenic diets

    SciTech Connect

    Van Middlesworth, L.

    1985-01-01

    Eight different sources of low-iodine diet (LID) were tested in mice over 14 years. The available iodine in each diet was measured by isotopic equilibration. Commercially prepared Remington diets contained 6.8 to 69.3 ng available iodine/g, and the results were usually different from shipment to shipment. Some samples produced greatly enlarged thyroids. The Remington diets from two sources were occasionally low in iodine but produced little thyroid enlargement. Between 1977 and 1980 only one shipment of Remington diet was found to contain less than 10 ng available I/g, and it resulted in large goiters. Since 1980 other compositions of LID have been used, but they caused additional abnormalities during breeding or chronic feeding. A low-iodine wheat diet produced goiter in mice more readily than in rats. In the course of testing for unavailable forms of dietary iodine, it was found that only 34.2% of thyroxine iodine was available to the thyroid iodine pool of mice. It is concluded that unidentified nutritional deficiency or dietary contaminants can alter the goitrogenic response to restricted iodine intake. Furthermore, at least one natural form of potential dietary iodine is incompletely available to mice.

  13. Geochemical Cycling of Iodine Species in Soils

    SciTech Connect

    Hu, Q; Moran, J E; Blackwood, V

    2007-08-23

    Iodine is an important element in studies of environmental protection and human health, global-scale hydrologic processes and nuclear nonproliferation. Biogeochemical cycling of iodine in soils is complex, because iodine occurs in multiple oxidation states and as inorganic and organic species that may be hydrophilic, atmophilic, and biophilic. In this study, we applied new analytical techniques to study the content and speciation of stable iodine in representative surface soils, and sorption and transport behavior of iodine species (iodide, iodate, and 4-iodoaniline) in sediments collected at numerous nuclear facilities in the United States, where anthropogenic {sup 129}I from prior nuclear fuel processing activities poses an environmental risk. The surface soil samples were chosen for their geographic locations (e.g., near the ocean or nuclear facilities) and for their differing physico-chemical characteristics (organic matter, texture, etc). Extracted solutions were analyzed by IC and ICP-MS methods to determine iodine concentrations and to examine iodine speciation (iodide, iodate, and organic iodine). In natural soils, iodine is mostly (nearly 90% of total iodine) present as organic species, while inorganic iodine becomes important (up to 50%) only in sediments with low organic matter. Results from laboratory column studies, aimed at examining transport of different iodine species, showed much greater retardation of 4-iodoaniline than iodide or iodate. Careful attention must be given to potential interconversion among species when interpreting the biogeochemical behavior of iodine in the environment. In addition to speciation, input concentration and residence time effects will influence the biogeochemical cycling of anthropogenic 129I deposited on surface soils.

  14. Iodine status in pregnancy and household salt iodine content in rural Bangladesh.

    PubMed

    Shamim, Abu Ahmed; Christian, Parul; Schulze, Kerry J; Ali, Hasmot; Kabir, Alamgir; Rashid, Mahbubur; Labrique, Alain; Salamatullah, Qauzi; West, Keith P

    2012-04-01

    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

  15. Effects of iodine intake and teat-dipping practices on milk iodine concentrations in dairy cows.

    PubMed

    Castro, S I Borucki; Berthiaume, R; Robichaud, A; Lacasse, P

    2012-01-01

    Two studies were conducted to determine the effects of dietary iodine and teat-dipping practices on iodine concentrations in milk. In the first study, 63 cows in mid lactation were assigned to a 33 factorial design in which the main effects were dietary iodine levels (0.3, 0.6, and 0.9 mg of dietary I/kg of dry matter) and 3 different postdip managements (chlorhexidine with dip cup, 1% iodine dip cup, and 1% iodine by manual spray). During the 13-d pre-experimental period and the 15-d experimental period, noniodized sanitizers were used in premilking management. During the pre-experimental period, the levels of milk iodine averaged 241.25.8 ?g/kg, and no relationship was found with lactation number, days in milk, or milk production. Milk iodine concentrations increased linearly with iodine intake. Although teat dipping with 1% iodine had no effect on milk iodine concentration, the same solution applied by spraying greatly increased milk iodine levels. The second study was conducted to determine the effects of udder preparation before milking on milk iodine concentrations. Thirty-two lactating cows were assigned to 4 treatments: no predip (Con); predip with a predip solution containing 0.5% iodine+complete cleaning (Comp); predip with a postdip solution containing 1% iodine+complete cleaning (Post); and predip with a predip solution containing 0.5% iodine+incomplete cleaning (Inc). During the 14-d pre-experimental period and the 19-d experimental period, cows were fed the same diet, and noniodized sanitizers were used for postmilking dipping. During the last week of treatment, milk iodine averaged 164, 189, 218, and 2529.8 ?g/kg for Con, Comp, Post, and Inc, respectively. Preplanned orthogonal contrasts indicated that predipping with a 0.5% iodine predip solution completely wiped off (Comp) tended to increase milk iodine content above that of the control and that the iodine content of Post and Inc were higher than that of the Comp treatment. The results of the first experiment confirm that, to preserve milk safety, iodine should not be fed above requirements. Spraying iodine-based teat-dipping solutions results in large increases in milk iodine content and should be avoided. Predipping teats with an iodine-based sanitizer is an acceptable practice, but must be performed with the appropriate product and completely wiped off before milking. PMID:22192200

  16. Iodine cyanide as volumetric oxidant.

    PubMed

    Paul, R C; Chauhan, R K; Sharma, N C; Parkash, R

    1971-11-01

    Iodine cyanide has been developed as an oxidant for the determination of iodide, sulphite, thiosulphate, thiocyanate, arsenic (III), antimony(III), tin(II), mercury(I), iron(II), ascorbic acid and beta-naphthol in dilute aqueous mineral acids, glacial acetic acid and 1:1 acetic acid-acetic anhydride mixture, with visual and potentiometric methods of end-point detection. PMID:18960997

  17. [Iodine resorption from PVP-iodine preparations after their use in humans].

    PubMed

    Glöbel, B; Glöbel, H; Andres, C

    1984-09-14

    The absorption of iodine from iodine-containing PVP preparations and the possibility of iodide being split off from the organic compound were tested in subjects with normal thyroid function after they had used PVP-iodine as mouth-antiseptic (15 subjects), vaginal gel (20 subjects) or liquid soap (20 subjects). Serum I-, T3, T4, TSH and urinary iodide excretion were measured, as an index of thyroid function, before and after the PVP application. Increase in iodine supply was up to 2 mg daily in the test subjects. The overwhelming proportion of the absorbed iodine (greater than 75%) was as organically bound iodine. In none of the subjects was there evidence of developing hyper- or hypothyroidism as a result of the additional iodine supply. Approximate values for the biological half-life and the distribution volume of total iodine in the body were also obtained. PMID:6479032

  18. Effect of iodine disinfectant source and water quality parameters on soluble iodine speciation

    NASA Technical Reports Server (NTRS)

    Silverstein, Joann; Hurst, Charles; Barkley, Robert; Dunham, Andrew

    1993-01-01

    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.

  19. Injection of iodine to the stratosphere

    NASA Astrophysics Data System (ADS)

    Saiz-Lopez, A.; Baidar, S.; Cuevas, C. A.; Koenig, T. K.; Fernandez, R. P.; Dix, B.; Kinnison, D. E.; Lamarque, J.-F.; Rodriguez-Lloveras, X.; Campos, T. L.; Volkamer, R.

    2015-08-01

    We report a new estimation of the injection of iodine into the stratosphere based on novel daytime (solar zenith angle < 45°) aircraft observations in the tropical tropopause layer and a global atmospheric model with the most recent knowledge about iodine photochemistry. The results indicate that significant levels of total reactive iodine (0.25-0.7 parts per trillion by volume), between 2 and 5 times larger than the accepted upper limits, can be injected into the stratosphere via tropical convective outflow. At these iodine levels, modeled iodine catalytic cycles account for up to 30% of the contemporary ozone loss in the tropical lower stratosphere and can exert a stratospheric ozone depletion potential equivalent to, or even larger than, that of very short-lived bromocarbons. Therefore, we suggest that iodine sources and chemistry need to be considered in assessments of the historical and future evolution of the stratospheric ozone layer.

  20. Atmospheric science: marine aerosols and iodine emissions.

    PubMed

    McFiggans, Gordon

    2005-02-10

    O'Dowd et al. describe the formation of marine aerosols from biogenic iodine and the growth of these aerosols into cloud-condensation nuclei (CCN). Based on chamber and modelling results, the authors suggest that biogenic organic iodine compounds emitted from macroalgae may be responsible for coastal particle bursts and that production of these compounds in the open ocean could increase CCN there too. It has since been shown that coastal particles are more likely to be produced from the photooxidation of molecular iodine. Moreover, I contend that open-ocean particle production and cloud enhancement do not result from emissions of organic iodine at atmospheric levels. For iodine particles to affect cloud properties over the remote ocean, an additional source of iodine is necessary as organic precursors cannot be responsible. PMID:15703706

  1. Exploding conducting film laser pumping apparatus

    DOEpatents

    Ware, K.D.; Jones, C.R.

    1984-04-27

    The 342-nm molecular iodine and the 1.315-..mu..m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

  2. Iodine chemistry in the water column of the Chesapeake Bay: Evidence for organic iodine forms

    NASA Astrophysics Data System (ADS)

    Luther, George W.; Ferdelman, Timothy; Culberson, Charles H.; Kostka, Joel; Wu, Jingfeng

    1991-03-01

    During the summer of 1987, we collected and analysed Chesapeake Bay water samples for the inorganic iodine species: iodide (by cathodic-stripping squarewave voltammetry) and iodate (by differential pulse polarography); and total iodine (by hypochlorite oxidation of the seawater sample to iodate). The difference between the sum of the inorganic iodine species and the total iodine was significant for about one-third of the samples collected from the Bay. Thus, in these samples, a third (or more) 'new' form(s) of iodine was present. These samples were primarily from oxygen-saturated surface waters of high biological activity (primary productivity and bacterial processes). This 'new' form can make up as much as 70% of the total iodine. Waters containing low oxygen concentrations showed less of this 'new' form of iodine whereas anoxic and sulphidic bottom waters contained only iodide. This 'new' form of iodine is organic in nature and probably non-volatile. It may reside in the peptide and humic fractions. Only reduced iodine (iodide and organic iodine) was detected in waters from the northern section of the Bay, whereas only iodide and iodate were detected in the southern section of the Bay. In only two samples were iodide, iodate and the 'new' form of iodine found to coexist. Iodide and organic iodine are probably cycled in the surface waters of the northern section of the Bay via a combination of biogeochemical and photochemical processes which produce the reactive intermediates, molecular iodine and hypoiodous acid. These react quickly with reduced inorganic and organic compounds to maintain the reduced forms of iodine in the water column. Only total iodine is conservative throughout the estuary. The inorganic iodine forms can be used as geochemical tracers.

  3. Determining median urinary iodine concentration that indicates adequate iodine intake at population level.

    PubMed Central

    Delange, François; de Benoist, Bruno; Burgi, Hans

    2002-01-01

    OBJECTIVE: Urinary iodine concentration is the prime indicator of nutritional iodine status and is used to evaluate population-based iodine supplementation. In 1994, WHO, UNICEF and ICCIDD recommended median urinary iodine concentrations for populations of 100- 200 micro g/l, assuming the 100 micro g/l threshold would limit concentrations <50 micro g/l to iodine in iodine-replete populations (schoolchildren and adults) and the proportion of concentrations <50 micro g/l. METHOD: A questionnaire on frequency distribution of urinary iodine in iodine-replete populations was circulated to 29 scientific groups. FINDINGS: Nineteen groups reported data from 48 populations with median urinary iodine concentrations >100 micro g/l. The total population was 55 892, including 35 661 (64%) schoolchildren. Median urinary iodine concentrations were 111-540 (median 201) micro g/l for all populations, 100-199 micro g/l in 23 (48%) populations and >/=200 micro g/l in 25 (52%). The frequencies of values <50 micro g/l were 0-20.8 (mean 4.8%) overall and 7.2% and 2.5% in populations with medians of 100-199 micro g/l and >200 micro g/l, respectively. The frequency reached 20% only in two places where iodine had been supplemented for <2 years. CONCLUSION: The frequency of urinary iodine concentrations <50 micro g/l in populations with median urinary iodine concentrations >/=100 micro g/l has been overestimated. The threshold of 100 micro g/l does not need to be increased. In populations, median urinary iodine concentrations of 100-200 micro g/l indicate adequate iodine intake and optimal iodine nutrition. PMID:12219154

  4. Salivary gland dysfunction following radioactive iodine therapy

    SciTech Connect

    Wiesenfeld, D.; Webster, G.; Cameron, F.; Ferguson, M.M.; MacFadyen, E.E.; MacFarlane, T.W.

    1983-02-01

    Radioactive iodine is used extensively for the treatment of thyrotoxicosis and thyroid carcinoma. Iodine is actively taken up by the salivary glands and, following its use, salivary dysfunction may result as a consequence of radiation damage. The literature is reviewed and a case is reported in which a patient presented with a significant increase in caries rate attributed to salivary dysfunction following radioactive iodine therapy for a thyroid carcinoma.

  5. Disposal of radioactive iodine in space

    NASA Technical Reports Server (NTRS)

    Burns, R. E.; Defield, J. G.

    1978-01-01

    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.

  6. Towards the eradication of iodine-deficiency disorders in Brazil through a salt iodination programme

    PubMed Central

    Medeiros-Neto, G. A.

    1988-01-01

    Iodine-deficiency disorders have been a serious public health problem in Brazil because of the failure of a salt iodination programme established in 1953. The reasons for this failure were logistical, e.g., potassium iodide was not supplied to all salt-producers, iodination of salt was largely erratic, and part of the population at risk used only non-refined salt, which was not iodinated. In 1978 a task force was therefore formed to implement measures to eliminate iodine-deficiency disorders from the country. For this purpose, potassium iodate was distributed, free-of-charge, to all salt mills and an iodate dosing spray was supplied without cost to small salt producers. Also, regional laboratories for determining iodine in salt were set up, inspectors made regular visits to the salt mills, and samples of salt from commerce and from the producers were analysed. More than 90% of the samples contained 10-30 mg iodine per kg. In three typical areas of the country with endemic goitre the urinary excretion of iodine increased from an average of less than 40 ?g iodine to 125 38 ?g iodine per g creatinine. In conclusion, the salt iodination programme was a complete success and could serve as a model for other countries with a high prevalence of iodine-deficiency disorders. PMID:3264765

  7. [CME: Radioactive iodine therapy in thyroid cancer].

    PubMed

    Steinert, Hans C; Aberle, Susanne

    2015-11-11

    Differentiated thyroid carcinomas represent about 90% of all thyroid tumors and are divided in papillary and follicular carcinomas. Their prognosis is good, however, recurrences are not rare. Their ability to accumulate iodine is used for the radioactive iodine treatment. The aim of the postoperative radioactive iodine ablation therapy is the complete elimination of remnant thyroid cells and sensitive staging (Fig. 1). The recurrence rate decreases after a complete thyroid ablation. Furthermore, thyroglobulin can be used as a sensitive tumor marker. Radioactive iodine treatment by itself describes the therapy of metastases. An exception is the papillary microcarcinoma, which in general is treated by a lobectomy alone. PMID:26558927

  8. Automated iodine monitor system. [for aqueous solutions

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The feasibility of a direct spectrophotometric measurement of iodine in water was established. An iodine colorimeter, was built to demonstrate the practicality of this technique. The specificity of this method was verified when applied to an on-line system where a reference solution cannot be used, and a preliminary design is presented for an automated iodine measuring and controlling system meeting the desired specifications. An Automated iodine monitor/controller system based on this preliminary design was built, tested, and delivered to the Johnson Space Center.

  9. Chalcogenide aerogels as sorbents for radioactive iodine

    SciTech Connect

    Subrahmanyam, Kota S.; Sarma, Debajit; Malliakas, Christos; Polychronopoulou, Kyriaki; Riley, Brian J.; Pierce, David A.; Chun, Jaehun; Kanatzidis, Mercouri G.

    2015-04-14

    Iodine (129I) is one of the radionuclides released in nuclear fuel reprocessing and poses risk to public safety due to its involvement in human metabolic processes. In order to prevent the leaching of hazardous radioactive iodine into the environment, its effective capture and sequestration is pivotal. In the context of finding a suitable matrix for capturing radioactive iodine the chalcogels, NiMoS4, CoMoS4, Sb4Sn4S12, Zn2Sn2S6, and CoSx (x = 4-5) were explored as iodine sorbents. All the chalcogels showed high uptake, reaching up to 225 mass% (2.25 g/g) of the final mass owing to strong chemical and physical iodine-chalcogen interactions. Analysis of the iodine-loaded specimens revealed that the iodine chemically reacted with Sb4Sn4S12, Zn2Sn2S6, and CoSx to form metal complexes SbI3, SnI4, and, KI respectively. The NiMoS4 and CoMoS4 chalcogels did not appear to undergo a chemical reaction with iodine since iodide complexes were not observed with these samples. Once heated, the iodine-loaded chalcogels released iodine in the temperature range of 75 °C to 220 °C, depending on the nature of iodine speciation. In the case of Sb4Sn4S12 and Zn2Sn2S6 iodine release was observed around 150 °C in the form of SnI4 and SbI3, respectively. The NiMoS4, CoMoS4, and CoSx released iodine at ~75 °C, which is consistent with physisorbed iodine. Preliminary investigations on consolidation of iodine-loaded Zn2Sn2S6 with Sb2S3 as a glass forming additive showed the content of iodine in consolidated glass ingots at around 25 mass%.

  10. Dietary restriction causing iodine-deficient goitre.

    PubMed

    Cheetham, Tim; Plumb, Emma; Callaghan, James; Jackson, Michael; Michaelis, Louise

    2015-08-01

    Iodine-deficient goitre was common in some parts of the UK prior to the introduction of salt iodisation. Many contemporary salt preparations do not contain much iodine, and there are renewed concerns about the iodine status of the population. We present a boy with severe allergy who developed goitre and significant thyroid dysfunction in association with an iodine-deficient 'food-restricted' diet. The case highlights the importance of a comprehensive nutritional assessment in all children on multiple food restrictions. PMID:26069028

  11. A resonance Raman/iodine Moessbauer investigation of the starch-iodine structure: aqueous solution and iodine vapor preparations. Interim report

    SciTech Connect

    Teitelbaum, R.C.; Ruby, S.L.; Marks, T.J.

    1980-03-05

    The structure of the blue-black iodine complex of amylose (the linear, helical component of starch) prepared either from iodine and iodide in aqueous solution or from crystalline amylose and iodine vapor, has been studied by resonance Raman and iodine-129 Moessbauer spectroscopy. In both cases it is concluded that the identity of the major chromophore is essentially the same: the pentaiodide (I(5-1)) anion. For the material prepared from iodine vapor, the iodide required for (I(5-1)) formation is produced by hydrolysis or alcoholysis of iodine. The other product of this reaction, a hypoiodite, has been assigned in the iodine Moessbauer spectrum.

  12. Lasing in atomic iodine with a nuclear-pumped XeBr* flash lamp

    SciTech Connect

    Williams, W.H.; Miley, G.H. )

    1993-04-12

    Excitation of the atomic iodine laser with a nuclear-pumped flash lamp is reported. The energetic reaction of thermal neutrons from a pulsed research reactor with [sup 3]He was used to excite the XeBr* excimer, and its spontaneous fluorescence at 282 nm, in turn, used to excite the iodine lasant ([ital i]-C[sub 3]F[sub 7]I). The peak fluorescence intensity was approximately twice the lasing threshold. Laser output at 1.31 [mu]m closely followed the neutron flux shape (over the 12 ms pulse), suggesting long pulse or cw operation is feasible. This represents the first laser pumped with a nuclear-driven flash lamp.

  13. Laser Fine-Adjustment Thruster For Space Vehicles

    SciTech Connect

    Rezunkov, Yu. A.; Egorov, M. S.; Repina, E. V.; Safronov, A. L.; Rebrov, S. G.

    2010-05-06

    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.

  14. Iodine transport analysis in the ESBWR.

    SciTech Connect

    Kalinich, Donald A.; Gauntt, Randall O.; Young, Michael Francis; Longmire, Pamela

    2009-03-01

    A simplified ESBWR MELCOR model was developed to track the transport of iodine released from damaged reactor fuel in a hypothesized core damage accident. To account for the effects of iodine pool chemistry, radiolysis of air and cable insulation, and surface coatings (i.e., paint) the iodine pool model in MELCOR was activated. Modifications were made to MELCOR to add sodium pentaborate as a buffer in the iodine pool chemistry model. An issue of specific interest was whether iodine vapor removed from the drywell vapor space by the PCCS heat exchangers would be sequestered in water pools or if it would be rereleased as vapor back into the drywell. As iodine vapor is not included in the deposition models for diffusiophoresis or thermophoresis in current version of MELCOR, a parametric study was conducted to evaluate the impact of a range of iodine removal coefficients in the PCCS heat exchangers. The study found that higher removal coefficients resulted in a lower mass of iodine vapor in the drywell vapor space.

  15. An Iodine Fluorescence Quenching Clock Reaction

    ERIC Educational Resources Information Center

    Weinberg, Richard B.; Muyskens, Mark

    2007-01-01

    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…

  16. An Iodine Fluorescence Quenching Clock Reaction

    ERIC Educational Resources Information Center

    Weinberg, Richard B.; Muyskens, Mark

    2007-01-01

    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

  17. Thioamination of Alkenes with Hypervalent Iodine Reagents.

    PubMed

    Mizar, Pushpak; Niebuhr, Rebecca; Hutchings, Matthew; Farooq, Umar; Wirth, Thomas

    2016-01-01

    An efficient thioamination of alkenes mediated by iodine(III) reagents is described. The use of different sulfur nucleophiles allows the flexible synthesis of 1,2-aminothiols from alkenes. By employing chiral iodine(III) reagents, a stereoselective version of the thioamination protocol has also been developed. PMID:26660291

  18. Iodine deficiency in vegetarians and vegans.

    PubMed

    Krajcovicov-Kudlckov, M; Buckov, K; Klimes, I; Sebokov, E

    2003-01-01

    Iodine content in food of plant origin is lower in comparison with that of animal origin due to a low iodine concentration in soil. Urinary iodine excretion was assessed in 15 vegans, 31 lacto- and lacto-ovovegetarians and 35 adults on a mixed diet. Iodine excretion was significantly lower in alternative nutrition groups - 172 microg/l in vegetarians and 78 microg/l in vegans compared to 216 microg/l in subjects on a mixed diet. One fourth of the vegetarians and 80% of the vegans suffer from iodine deficiency (iodine excretion value below 100 microg/l) compared to 9% in the persons on a mixed nutrition. The results show that under conditions of alternative nutrition, there is a higher prevalence of iodine deficiency, which might be a consequence of exclusive or prevailing consumption of food of plant origin, no intake of fish and other sea products, as well as reduced iodine intake in the form of sea salt. PMID:12748410

  19. Thioamination of Alkenes with Hypervalent Iodine Reagents

    PubMed Central

    Mizar, Pushpak; Niebuhr, Rebecca; Hutchings, Matthew; Farooq, Umar; Wirth, Thomas

    2016-01-01

    An efficient thioamination of alkenes mediated by iodine(III) reagents is described. The use of different sulfur nucleophiles allows the flexible synthesis of 1,2-aminothiols from alkenes. By employing chiral iodine(III) reagents, a stereoselective version of the thioamination protocol has also been developed. PMID:26660291

  20. On the structure of carotenoid iodine complexes.

    PubMed

    Lutnaes, Bjart Frode; Krane, Jostein; Liaaen-Jensen, Synnove

    2004-10-01

    Previous work on carotenoid-iodine complexes is briefly reviewed. The formation of iodine complexes of beta,beta-carotene and of (3R,3' R )-beta,beta-carotene-3,3'-diol (zeaxanthin) has been studied by modern methods including UV/VIS/NIR, IR MS, EPR, ENDOR and NMR (1H, 1H-1H COSY, TOCSY, 2D ROESY, 1H-13C HSQC and 1H-13C HMBC) spectroscopy, and chemical reactions monitored by HPLC, TLC and spectral analysis (VIS, MS, 1H NMR). beta,beta-Carotene formed a solid complex C40H56 x 4I with iodine in hexane and a solvent complex with lambdamax 1010 nm in chlorinated solvents. Iodine was not covalently bound to the carotene. Spectroscopic and chemical evidence is consistent with the representation of the beta,beta-carotene-iodine complex containing iodine in a pi complex with cationic/radical cationic properties. Extensive E/Z isomerisation was noted for all quenching products obtained in acetone, with thiosulfate, by dilution, or by reaction with nucleophile (MeOH). Key products obtained from the beta,beta-carotene-iodine complex were 4',5'-didehydro-4,5'-retro-beta,beta-carotene (isocarotene) and 4-methoxy-beta,beta-carotene. The zeaxanthin-iodine complex was not suitable for a practical synthesis of (3S,3'S)-4',5'-didehydro-4,5'-retro-beta,beta-carotene-3,3'-diol (eschscholtzxanthin). PMID:15455156

  1. Spectral properties of molecular iodine in absorption cells filled to specified saturation pressure.

    PubMed

    Hrabina, Jan; Šarbort, Martin; Acef, Ouali; Burck, Frédéric Du; Chiodo, Nicola; Holá, Miroslava; Číp, Ondřej; Lazar, Josef

    2014-11-01

    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

  2. Iodine concentration of organic and conventional milk: implications for iodine intake.

    PubMed

    Bath, Sarah C; Button, Suzanne; Rayman, Margaret P

    2012-04-01

    Iodine is required for adequate thyroid hormone production, which is essential for brain development, particularly in the first trimester of pregnancy. Milk is the principal source of iodine in UK diets, and while small studies in Europe have shown organic milk to have a lower iodine concentration than conventional milk, no such study has been conducted in Britain. In view of the increasing popularity of organic milk in the UK, we aimed to compare the iodine concentration of retail organic and conventional milk and to evaluate regional influences in iodine levels. Samples of organic milk (n 92) and conventional milk (n 80), purchased from retail outlets in sixteen areas of the UK (southern England, Wales and Northern Ireland), were analysed for iodine using inductively coupled plasma MS. The region of origin of the milk was determined from information on the label. Organic milk was 421 % lower in iodine content than conventional milk (median iodine concentration 1445 v. 2495 ng/g; P < 0001). There was no difference in the iodine concentration of either conventional or organic milk by area of purchase. However, a difference was seen in iodine concentration of organic milk by region of origin (P < 0001). The lower iodine concentration of organic milk has public-health implications, particularly in view of emerging evidence of iodine deficiency in UK population sub-groups, including pregnant women. Individuals who choose organic milk should be aware that their iodine intake may be compromised and should ensure adequate iodine intake from alternative sources. PMID:21781365

  3. Immobilization of iodine in soil-water systems and its relation to iodine species

    NASA Astrophysics Data System (ADS)

    Shimamoto, Y.; Takahashi, Y.

    2009-12-01

    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.

  4. The importance of iodine in public health.

    PubMed

    Lazarus, John H

    2015-08-01

    Iodine (I) deficiency has been known for more than a century and is known to cause cretinism at the extreme end of the spectrum but also, importantly, impaired development and neurocognition in areas of mild deficiency. The WHO has indicated that median urinary iodine of 100-199 μg/l in a population is regarded as indicative of an adequate iodine intake. The understanding of the spectrum of iodine deficiency disorders led to the formation of The International Council for the Control of Iodine Deficiency Disorders which has promulgated the use of household iodized salt and the use of such salt in food processing and manufacture. Iodine deficiency is particularly important in pregnancy as the fetus relies on maternal thyroxine (T4) exclusively during the first 14 weeks and also throughout gestation. As this hormone is critical to brain and nervous system maturation, low maternal T4 results in low child intelligence quotient. The recommendation for I intake in pregnancy is 250 μg/day to prevent fetal and child brain function impairment. During the past 25 years, the number of countries with I deficiency has reduced to 32; these still include many European developed countries. Sustainability of adequate iodine status must be achieved by continuous monitoring and where this has not been performed I deficiency has often recurred. More randomized controlled trials of iodine supplementation in pregnancy are required in mild iodine-deficient areas to inform public health strategy and subsequent government action on suitable provision of iodine to the population at risk. PMID:25663362

  5. Thermochemistry of small iodine species

    NASA Astrophysics Data System (ADS)

    ulkov, K.; Federi?, J.; Louis, F.; Cantrel, L.; Demovi?, L.; ?ernuk, I.

    2013-11-01

    We present a systematic study of the thermochemistry for a set of iodine species relevant to atmospheric chemistry. The reactions include H, O and I atoms and H2, OH, HI, I2, iodine monoxide, hypoiodous acid (HOI) and H2O species. The calculations presented were performed using completely renormalized coupled cluster theory including single, double and non-iterative triple substitutions in conjunction with the ANO-RCC basis sets developed for scalar relativistic calculations. The second-order spin-free Douglas-Kroll-Hess Hamiltonian was used to account for the scalar relativistic effects. The calculations also included spin-orbit corrections and semi-core correlation contributions. The resulting reaction enthalpies and Gibbs energies at 298 K have been compared with the experimental data. On the basis of a set of selected reactions we suggest an updated value for ? f H298K of HOI based on the set of isogyric reactions: -69.0 3.7 kJ mol-1.

  6. Use of iodine for water disinfection: iodine toxicity and maximum recommended dose.

    PubMed Central

    Backer, H; Hollowell, J

    2000-01-01

    Iodine is an effective, simple, and cost-efficient means of water disinfection for people who vacation, travel, or work in areas where municipal water treatment is not reliable. However, there is considerable controversy about the maximum safe iodine dose and duration of use when iodine is ingested in excess of the recommended daily dietary amount. The major health effect of concern with excess iodine ingestion is thyroid disorders, primarily hypothyroidism with or without iodine-induced goiter. A review of the human trials on the safety of iodine ingestion indicates that neither the maximum recommended dietary dose (2 mg/day) nor the maximum recommended duration of use (3 weeks) has a firm basis. Rather than a clear threshold response level or a linear and temporal dose-response relationship between iodine intake and thyroid function, there appears to be marked individual sensitivity, often resulting from unmasking of underlying thyroid disease. The use of iodine for water disinfection requires a risk-benefit decision based on iodine's benefit as a disinfectant and the changes it induces in thyroid physiology. By using appropriate disinfection techniques and monitoring thyroid function, most people can use iodine for water treatment over a prolonged period of time. PMID:10964787

  7. Rechargeable Lithium-Iodine Batteries with Iodine/Nanoporous Carbon Cathode.

    PubMed

    Zhao, Qing; Lu, Yanying; Zhu, Zhiqiang; Tao, Zhanliang; Chen, Jun

    2015-09-01

    Rechargeable Li-iodine batteries are attractive electrochemical energy storage systems because iodine cathode provides the possibility of high energy density, wide abundance and low cost. However, the safety risk caused by low thermostability of iodine and the self-discharge reaction due to high solvency of iodine in aprotic solvent are target issues to be considered. Herein, we designed a room-temperature "solution-adsorption" method to prepare a thermostable iodine-carbon cathode by utilizing the strong adsorption of nanoporous carbon. Meanwhile, Li-iodine batteries constructed by the as-prepared cathode and ether-based electrolyte with the addition of LiNO3 showed negligible self-discharge reaction, high rate and long cycling performance. The reversible reactions of I2/LiI3 and LiI3/LiI in Li-iodine batteries were also proved with in situ Raman measurement. For the demonstration of application, soft-package batteries with Al-plastic film were assembled, displaying energy densities of 475 Wh/kg by mass of Li and iodine, and 136 Wh/kg by total mass of the battery. The use of nanoporous carbon to adsorb iodine at room-temperature represents a new and promising direction for realizing high-performance cathode for rechargeable Li-iodine batteries. PMID:26241461

  8. Urinary Iodine Clearance following Iodinated Contrast Administration: A Comparison of Euthyroid and Postthyroidectomy Subjects

    PubMed Central

    Ho, Janice D.; Tsang, James F.; Scoggan, Kylie A.; Leslie, William D.

    2014-01-01

    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

  9. Current global iodine status and progress over the last decade towards the elimination of iodine deficiency.

    PubMed Central

    Andersson, Maria; Takkouche, Bahi; Egli, Ines; Allen, Henrietta E.; de Benoist, Bruno

    2005-01-01

    OBJECTIVE: To estimate worldwide iodine nutrition and monitor country progress towards sustained elimination of iodine deficiency disorders. METHODS: Cross-sectional data on urinary iodine (UI) and total goitre prevalence (TGP) in school-age children from 1993-2003 compiled in the WHO Global Database on Iodine Deficiency were analysed. The median UI was used to classify countries according to the public health significance of their iodine nutrition status. Estimates of the global and regional populations with insufficient iodine intake were based on the proportion of each country's population with UI below 100 microg/l. TGP was computed for trend analysis over 10 years. FINDINGS: UI data were available for 92.1% of the world's school-age children. Iodine deficiency is still a public health problem in 54 countries. A total of 36.5% (285 million) school-age children were estimated to have an insufficient iodine intake, ranging from 10.1% in the WHO Region of the Americas to 59.9% in the European Region. Extrapolating this prevalence to the general population generated an estimate of nearly two billion individuals with insufficient iodine intake. Iodine intake was more than adequate, or excessive, in 29 countries. Global TGP in the general population was 15.8%. CONCLUSION: Forty-three countries have reached optimal iodine nutrition. Strengthened UI monitoring is required to ensure that salt iodization is having the desired impact, to identify at-risk populations and to ensure sustainable prevention and control of iodine deficiency. Efforts to eliminate iodine deficiency should be maintained and expanded. PMID:16175826

  10. An evaluation of the suitability of laser-induced fluorescence for measurements of fission-product iodine sorptivity in the MHTGR [modular high-temperature gas-cooled reactor

    SciTech Connect

    Sherrow, S.A.

    1989-07-01

    Experiments and calculations indicate that laser-induced fluorescence (LIF) lacks the sensitivity needed for sorptivity measurements of I{sub 2} or other molecular species at partial pressures below 10{sup {minus}11} atm. Although the technique may have sufficient sensitivity for measurements of atomic species, the species of interest are, in all likelihood, not atomic. Methods of measurement which would allow the determination of species are proposed. 9 refs., 6 figs.

  11. Acquired hypothyroidism due to iodine deficiency in an American child.

    PubMed

    Brooks, Merrian J; Post, Ernest M

    2014-11-01

    Acquired hypothyroidism secondary to iodine deficiency is rarely reported in iodine-replete environments. The case of a 9-year-old patient with severe acquired hypothyroidism due to iodine deficiency is presented. His deficiency occurred because of a restrictive diet used to control eosinophilic esophagitis. Hypothyroidism and iodine deficiency were quickly corrected with a kelp supplement. PMID:25003378

  12. History of U.S. Iodine Fortification and Supplementation

    PubMed Central

    Leung, Angela M.; Braverman, Lewis E.; Pearce, Elizabeth N.

    2012-01-01

    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

  13. [Characteristics of iodine uptake and accumulation by vegetables].

    PubMed

    Hong, Chun-Lai; Weng, Huan-Xin; Yan, Ai-Lan; Xie, Ling-Li

    2007-10-01

    With seaweed iodine and KI as exogenous iodine sources, a pot experiment was conducted to study the characteristics of iodine uptake and accumulation by pakchoi cabbage, celery, capsicum, and radish. The results showed that the iodine content in the edible parts of test vegetables increased with increasing amount of exogenous iodine, but the iodine accumulation rate differed with the kinds of vegetables, in the order of pakchoi > celery > radish > capsicum. The majority of iodine was accumulated in roots, with lesser amount transferred to shoots. The distribution of iodine in vegetables was commonly in the order of root > leaf > stem > fruit, but the iodine in radish is lower in its rhizome than in its shoot. Low concentrations (0-25 mg x kg(-1)) of exogenous iodine had little effects on the growth of vegetables, while high concentrations (> or = 50 mg x kg(-1)) of it had inhibitory effects, resulting in a decreased vegetable biomass. The sensitivity of test vegetables to the adverse effect of exogenous iodine was in the order of capsicum > pachoi > celery > radish. Compared with seaweed iodine, KI decreased the biomass of first cutting significantly (P < 0.05), but for the second cutting, little difference was observed between these two iodine sources. The uptake and accumulation of these two iodine sources by vegetables also differed with cuttings, i.e., the first cutting vegetables absorbed more KI, while the second cutting vegetables absorbed more seaweed iodine (P < 0.05), suggesting that seaweed iodine had a longer efficacy than KI. PMID:18163316

  14. Computation of iodine species concentrations in water

    NASA Technical Reports Server (NTRS)

    Schultz, John R.; Mudgett, Paul D.; Flanagan, David T.; Sauer, Richard L.

    1994-01-01

    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.

  15. Method and apparatus for removing iodine from a nuclear reactor coolant

    DOEpatents

    Cooper, Martin H.

    1980-01-01

    A method and apparatus for removing iodine-131 and iodine-125 from a liquid sodium reactor coolant. Non-radioactive iodine is dissolved in hot liquid sodium to increase the total iodine concentration. Subsequent precipitation of the iodine in a cold trap removes both the radioactive iodine isotopes as well as the non-radioactive iodine.

  16. Effect of chronic douching with polyvinylpyrrolidone-iodine on iodine absorption and thyroid function

    SciTech Connect

    Safran, M.; Braverman, L.E.

    1982-07-01

    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.

  17. Method for immobilizing radioactive iodine

    DOEpatents

    Babad, Harry; Strachan, Denis M.

    1980-01-01

    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.

  18. A model to secure a stable iodine concentration in milk

    PubMed Central

    Trøan, Gisken; Dahl, Lisbeth; Meltzer, Helle Margrete; Abel, Marianne Hope; Indahl, Ulf Geir; Haug, Anna; Prestløkken, Egil

    2015-01-01

    Background Dairy products account for approximately 60% of the iodine intake in the Norwegian population. The iodine concentration in cow's milk varies considerably, depending on feeding practices, season, and amount of iodine and rapeseed products in cow fodder. The variation in iodine in milk affects the risk of iodine deficiency or excess in the population. Objective The first goal of this study was to develop a model to predict the iodine concentration in milk based on the concentration of iodine and rapeseed or glucosinolate in feed, as a tool to securing stable iodine concentration in milk. A second aim was to estimate the impact of different iodine levels in milk on iodine nutrition in the Norwegian population. Design Two models were developed on the basis of results from eight published and two unpublished studies from the past 20 years. The models were based on different iodine concentrations in the fodder combined with either glucosinolate (Model 1) or rapeseed cake/meal (Model 2). To illustrate the impact of different iodine concentrations in milk on iodine intake, we simulated the iodine contribution from dairy products in different population groups based on food intake data in the most recent dietary surveys in Norway. Results The models developed could predict iodine concentration in milk. Cross-validation showed good fit and confirmed the explanatory power of the models. Our calculations showed that dairy products with current iodine level in milk (200 µg/kg) cover 68, 49, 108 and 56% of the daily iodine requirements for men, women, 2-year-old children, and pregnant women, respectively. Conclusions Securing a stable level of iodine in milk by adjusting iodine concentration in different cow feeds is thus important for preventing excess intake in small children and iodine deficiency in pregnant and non-pregnant women. PMID:26689316

  19. Probing starch-iodine interaction by atomic force microscopy.

    PubMed

    Du, Xiongwei; An, Hongjie; Liu, Zhongdong; Yang, Hongshun; Wei, Lijuan

    2014-01-01

    We explored the interaction of iodine with three crystalline type starches, corn, potato, and sweet potato starches using atomic force microscopy. Results revealed that starch molecules aggregated through interaction with iodine solution as well as iodine vapor. Detailed fine structures such as networks, chains, and super-helical structures were found in iodide solution tests. The nanostructures formed due to iodine adsorption could help to understand the formation and properties of the starch-iodine complex. PMID:24338992

  20. [Iodine content in breast milk of nursing mother in norme and premature birth].

    PubMed

    Sen'kevich, O A; Sirotina, Z V; Koval'ski?, Iu G; Golik, L S

    2008-01-01

    Iodine content in breast milk depends on the consumption level of iodine. Iodine deficiency in mothers results in inadequate iodine status of neonates. Premature birth effect on iodine excretion with urine and iodine content in breast milk was investigated. Breast milk iodine concentrations did not differ for healthy women and women with premature birth, but the values were lower than the optimal value. Iodine supplements at any gestation stage normalized iodine content in breast milk. PMID:19227869

  1. Low Iodine Diet for Preparation for Radioactive Iodine Therapy in Differentiated Thyroid Carcinoma in Korea

    PubMed Central

    2013-01-01

    Preparation for radioactive iodine (RAI) therapy includes an increased serum thyroid stimulating hormone level and a low iodine diet (LID). Because of extremely high iodine intake, some physicians have advocated a more stringent LID for greater than 2 weeks in Korean patients with thyroid cancer prior to RAI therapy; however, it is very difficult to maintain a stringent LID for a longer period of time. According to recent reports in Korea, a nonstringent, simple LID for only 1 week might be enough prior to RAI therapy, if the patients can be educated intensively by specially trained staff. The measurement of simple urinary iodine concentration (UIC; µg/L) may underestimate daily iodine excretion in patients with a urinary volume of more than 1 L/day and can also be affected by dilution status. Simple UIC had a weaker correlation than the iodine/creatinine (I/Cr) ratio. Therefore, the urinary I/Cr ratio can replace 24-hour urine iodine excretion instead of simple UIC, although it may overestimate iodine intake in patients with malnutrition or poor muscle mass. The measurement of serum iodine level might be useful as an adjunct parameter for assessing LID preparation, but its sensitivity and specificity were relatively low compared to the urinary I/Cr ratio. PMID:24396673

  2. Low iodine diet for preparation for radioactive iodine therapy in differentiated thyroid carcinoma in Korea.

    PubMed

    Chung, Jae Hoon

    2013-09-01

    Preparation for radioactive iodine (RAI) therapy includes an increased serum thyroid stimulating hormone level and a low iodine diet (LID). Because of extremely high iodine intake, some physicians have advocated a more stringent LID for greater than 2 weeks in Korean patients with thyroid cancer prior to RAI therapy; however, it is very difficult to maintain a stringent LID for a longer period of time. According to recent reports in Korea, a nonstringent, simple LID for only 1 week might be enough prior to RAI therapy, if the patients can be educated intensively by specially trained staff. The measurement of simple urinary iodine concentration (UIC; g/L) may underestimate daily iodine excretion in patients with a urinary volume of more than 1 L/day and can also be affected by dilution status. Simple UIC had a weaker correlation than the iodine/creatinine (I/Cr) ratio. Therefore, the urinary I/Cr ratio can replace 24-hour urine iodine excretion instead of simple UIC, although it may overestimate iodine intake in patients with malnutrition or poor muscle mass. The measurement of serum iodine level might be useful as an adjunct parameter for assessing LID preparation, but its sensitivity and specificity were relatively low compared to the urinary I/Cr ratio. PMID:24396673

  3. Nuclear pumped laser research at the Jet Propulsion Laboratory

    NASA Technical Reports Server (NTRS)

    Russell, G. R.

    1979-01-01

    Using a partially nuclear excited xenon flashlamp to pump an iodine laser, laser pulse shapes were analyzed with and without nuclear flashlamp augmentation. The pulse shapes indicate that the deposition of nuclear energy is equally as effective as electrical energy deposition in producing laser pulse energy output. The amplification of the E-beam pumped CF3I was measured at pressures of several atmospheres. Preliminary data shows that, for a part of the iodine laser pulse, amplification of almost a factor of two is measured. This measurement indicates that the gain in an E-beam pumped CF3I is an order of magnitude greater than in the coaxial laser tube.

  4. 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 combination, research results, and ongoing clinical trials.

  5. Teaching the Rovibronic Spectroscopy of Molecular Iodine

    ERIC Educational Resources Information Center

    Williamson, J. Charles

    2007-01-01

    The rovibronic spectroscopy of molecular iodine provides a clearer understanding of the electronic potential parameters of various systems to the undergraduate students. The technique also helps them to test the various other quantum mechanical concepts.

  6. The Electronic Spectrum of Iodine Revisited.

    ERIC Educational Resources Information Center

    McNaught, Ian J.

    1980-01-01

    Presents equations and techniques for calculating and interpreting many of the spectroscopically important parameters associated with the ground and second excited states of the iodine molecule. (Author/CS)

  7. Modeling the complex bromate-iodine reaction.

    PubMed

    Machado, Priscilla B; Faria, Roberto B

    2009-05-01

    In this article, it is shown that the FLEK model (ref 5 ) is able to model the experimental results of the bromate-iodine clock reaction. Five different complex chemical systems, the bromate-iodide clock and oscillating reactions, the bromite-iodide clock and oscillating reactions, and now the bromate-iodine clock reaction are adequately accounted for by the FLEK model. PMID:19361181

  8. The chlorate-iodine clock reaction.

    PubMed

    Oliveira, Andr P; Faria, Roberto B

    2005-12-28

    A clock reaction produced by mixing chlorate and iodine solutions in perchloric acid media is reported. This is the first example of a clock reaction using chlorate as a reagent. Increasing chlorate and acid concentration reduces the induction period. Changing the initial iodine concentration does not affect the length of the induction period. The discovery of this clock reaction opens the possibility that a new family of oscillation reactions can be built using chlorate as reagent. PMID:16366551

  9. Iodine: a pathfinder for petroleum deposits

    SciTech Connect

    Gallagher, A.V.

    1983-03-01

    The relationship between oil and gas fields and high concentrations of iodine in water is well known. Iodine is a good, indirect surface indicator of areas favorable for oil and gas accumulations. Humic substances are the main initial source of iodine in subsurface waters. At the high temperatures achieved during burial, structural degradation of large molecules of unsaponified organic matter and of insoluble residues and bitumens also provide a source of iodine. Samples are taken from the top 2 to 4 in. (5 to 10 cm) of the soil and are analyzed for total iodine content. Depth appears to influence the extent of iodide fixation by clay soils. Clays obtained from different depths of soils located within the water table do not record any difference in iodide fixation; however, identification of the sand/clay ratio in the 170 mesh soil sample is important. High iodine concentrations occur about the perimeter of a surface geochemical anomaly. This surface expression of the reduction chimney, the so-called halo effect, is associated with oil and gas anomalies. A typical anomaly exhibits values greater than two standard deviations above the statistical mean. Iodine is an effective pathfinder in surface prospecting because of: (1) the simplicity of taking and non-critical handling required of the surface samples, (2) the ability to integrate a detailed survey into an earlier reconnaissance survey, and (3) relatively low-cost analysis permits a greater sampling density, which provides better identification and definition of anomalies. Iodine, as all geochemical parameters, should not be used by itself, but rather in combination with other geochemical techniques, and the results should be cross-correlated for an optimum confidence level.

  10. Regenerable Iodine Water-Disinfection System

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

    1994-01-01

    Iodinated resin bed for disinfecting water regenerated to extend useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle manually controlled readily automated to start and stop according to signals from concentration sensors. Further benefit of regeneration is bed provides highly concentrated biocide source when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

  11. Exploding conducting film laser pumping apparatus

    DOEpatents

    Ware, Kenneth D.; Jones, Claude R.

    1986-01-01

    Exploding conducting film laser optical pumping apparatus. The 342-nm molecular iodine and the 1.315-.mu.m atomic iodine lasers have been optically pumped by intense light from exploding-metal-film discharges. Brightness temperatures for the exploding-film discharges were approximately 25,000 K. Although lower output energies were achieved for such discharges when compared to exploding-wire techniques, the larger surface area and smaller inductance inherent in the exploding-film should lead to improved efficiency for optically-pumped gas lasers.

  12. Urinary iodine excretion in healthy Mexican adults.

    PubMed

    Flores-Rebollar, Armando; Lendechy Velzquez, Marisol; Castro Snchez, Andrea; Lpez Carrasco, Guadalupe; Ruiz Juvera, Ada

    2014-09-01

    The iodine nutritional status of a population is mainly measured by urinary iodine excretion (UI) and thyroid volume determined by ultrasound (US). The surveillance of nutritional iodine levels in the Mexican population has been insufficient. Our aim was to determine the UI in random samples from adults living in an urban area. We selected a sample of healthy individuals over the age of 18 that were students, physicians or administrative personnel at our Institution and had no known thyroid disease. Thyroid volume was determined by ultrasound in all volunteers as well as thyroid hormones and antithyroid antibodies and a urine sample was obtained. One hundred and two volunteers with a median age of 29, participated in the study. The group's median UI was 221 ?g/L, interquartile range (IQR) (135.0 to 356.8) and no differences were observed between genders: women had a UI of 218.0 ?g/L IQR (129.0 a 351.0) vs. 223.0 ?g/L IQR (138.0 to 374.0) in males, p 0.941. Excessive dietary iodine intake was established in 31.4% of all volunteers according to their UI, placing them at risk of thyroid dysfunction. It is fundamental to evaluate the national iodine nutritional status in Mexico. We discuss the current status of the nutritional state in the Americas, emphasizing that in Latin America and the observed tendency in the region to ingest a diet high in iodine. PMID:26137791

  13. Study of iodine diffusion in silicon carbide

    NASA Astrophysics Data System (ADS)

    Friedland, E.; van der Berg, N. G.; Malherbe, J. B.; Kuhudzai, R. J.; Botha, A. J.; Wendler, E.; Wesch, W.

    2010-10-01

    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.

  14. Modern and past volcanic degassing of iodine

    NASA Astrophysics Data System (ADS)

    Bureau, H.; Auzende, A.-L.; Marocchi, M.; Raepsaet, C.; Munsch, P.; Testemale, D.; Mézouar, M.; Kubsky, S.; Carrière, M.; Ricolleau, A.; Fiquet, G.

    2016-01-01

    We have monitored iodine degassing from a melt to a water vapor during decompression (i.e. magma ascent). Experiments have been performed by combining diamond anvil cells experiments with synchrotron X-rays fluorescence analysis. Partition coefficients DIfluid/melt measured for a pressure and temperature range of 0.1-1.8 GPa and 500-900 °C, range from 41 to 1.92, values for room conditions DIfluid/glass (quenched samples) are equal to or higher than 350. We show that iodine degassing with water is earlier and much more efficient than for lighter halogen elements, Cl and Br. Iodine is totally degassed from the silicate melt at room conditions. By applying these results to modern volcanology, we calculate an annual iodine flux for subduction related volcanism of 0.16-2.4 kt yr-1. We suggest that the natural iodine degassing may be underestimated, having possible consequences on the Earth's ozone destruction cycle. By applying this results to the Early Earth, we propose a process that may explain the contrasted signature of I, Br and Cl, strongly depleted in the bulk silicate Earth, the most depleted being iodine, whereas fluorine is almost enriched. The Earth may have lost heavy halogen elements during an early water degassing process from the magma ocean.

  15. Prospects of a visible (green) chemical laser

    SciTech Connect

    Herbelin, J.M.

    1986-07-01

    The experimental conditions for a 1.25-kW visible (green) chemical laser are detailed. In this system, a supersonic oxygen--iodine laser is optically coupled straightforwardly to a nitrogen flouride DFlike supersonic flow. The design conditions presented here are based on previously unpublished experimental and theoretical results that are shown to be in good agreement.

  16. Theoretical studies of solar lasers and converters

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.

    1990-01-01

    The research described consisted of developing and refining the continuous flow laser model program including the creation of a working model. The mathematical development of a two pass amplifier for an iodine laser is summarized. A computer program for the amplifier's simulation is included with output from the simulation model.

  17. Effect of iodine disinfection products on higher plants

    NASA Technical Reports Server (NTRS)

    Janik, D.; Macler, B.; Macelroy, R. D.; Thorstenson, Y.; Sauer, R.

    1989-01-01

    Iodine is used to disinfect potable water on United States spacecraft. Iodinated potable water will likely be used to grow plants in space. Little is known about the effects of iodine disinfection products on plants. Seeds of select higher plants were germinated in water iodinated using the Shuttle Microbial Check Valve, and water to which measured amounts of iodine was added. Percent germination was decreased in seeds of most species germinated in iodinated water. Beans were most affected. Germination rates, determined from germination half-times, were decreased for beans germinated in iodinated water, and water to which iodide was added. Development was retarded and rootlets were conspicuously absent in bean and several other plant species germinated in iodinated water. Iodide alone did not elicit these responses. Clearly iodine disinfection products can affect higher plants. These effects must be carefully considered for plant experimentation and cultivation in space, and in design and testing of closed environmental life support systems.

  18. Iodine derivatives of chemically modified gum Arabic microspheres.

    PubMed

    Ganie, Showkat A; Ali, Akbar; Mazumdar, Nasreen

    2015-09-20

    Acetylated gum Arabic (AGA) derivatives with different degrees of substitution (DS 0.97-2.74) were synthesized using acetyl chloride and a base under varying reaction conditions. The AGA derivatives were obtained in the form of microspheres and thereafter stable iodine products were prepared by doping the microspheres with an iodinating agent, iodine monochloride (ICl). The reaction between electrophilic iodine and polar carbonyl groups was studied by FT-IR, (1)H-NMR, and UV-VIS spectroscopies. The products were also characterized by DSC, TGA and SEM studies. The incorporated iodine was released in aqueous medium as iodide ions (I(-)). A reaction scheme has been proposed for the iodination and de-iodination of the gum derivatives. This work suggests that the iodine derivatives of modified gum Arabic could be used as a source of iodide ions which is the nutritional form of iodine. PMID:26050909

  19. A solar simulator-pumped gas laser for the direct conversion of solar energy

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    Most proposed space power systems are comprised of three general stages, including the collection of the solar radiation, the conversion to a useful form, and the transmission to a receiver. The solar-pumped laser, however, effectively eliminates the middle stage and offers direct photon-to-photon conversion. The laser is especially suited for space-to-space power transmission and communication because of minimal beam spread, low power loss over large distances, and extreme energy densities. A description is presented of the first gas laser pumped by a solar simulator that is scalable to high power levels. The lasant is an iodide C3F7I that as a laser-fusion driver has produced terawatt peak power levels.

  20. Iodine status in pre-school children prior to mandatory iodine fortification in Australia.

    PubMed

    Skeaff, Sheila; Zhao, Ying; Gibson, Robert; Makrides, Maria; Zhou, Shao Jia

    2014-04-01

    The iodine status of children between the ages of 5 and 15 years has been routinely assessed in many countries, but few studies have examined iodine status in pre-school children. We conducted a cross-sectional study of pre-school children living in Adelaide, South Australia, between 2005 and 2007. Children 1-5 years old were identified using a unique sampling strategy to ensure that the study population was representative. A 3-day weighed diet record, a blood sample and a urine sample were obtained from each child. The median urinary iodine concentration (UIC) of the children (n = 279) was 129 g L(-1), indicating iodine sufficiency (normal range: 100-199 g L(-1)), but 35% of the children had a UIC < 100 g L(-1). The median thyroglobulin concentration of children (n = 217) was 24 g L(-1) and thyroglobulin concentration declined with increasing age (P = 0.024). The mean daily iodine intake was 76 g. The intake of iodine was lower than expected and highlights difficulties in accurately assessing iodine intakes. Further studies are needed to monitor dietary changes and iodine status in this age group since the implementation of mandatory fortification of bread with iodised salt in Australia in 2009. PMID:22642303

  1. Mixed-layered bismuth-oxygen-iodine materials for capture and waste disposal of radioactive iodine

    DOEpatents

    Krumhansl, James L; Nenoff, Tina M

    2013-02-26

    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.

  2. Mixed-layered bismuth--oxygen--iodine materials for capture and waste disposal of radioactive iodine

    DOEpatents

    Krumhansl, James L; Nenoff, Tina M

    2015-01-06

    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.

  3. Effects of Increased Iodine Intake on Thyroid Disorders

    PubMed Central

    Sun, Xin; Shan, Zhongyan

    2014-01-01

    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

  4. Iodine-129 Dose in LLW Disposal Facility Performance Assessments

    SciTech Connect

    Wilhite, E.L.

    1999-10-15

    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.

  5. 40 CFR 415.430 - Applicability; description of the iodine production subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... iodine production subcategory. 415.430 Section 415.430 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Iodine Production Subcategory § 415.430 Applicability; description of the iodine production... iodine....

  6. 40 CFR 415.430 - Applicability; description of the iodine production subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... iodine production subcategory. 415.430 Section 415.430 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Iodine Production Subcategory § 415.430 Applicability; description of the iodine production... iodine....

  7. 40 CFR 415.430 - Applicability; description of the iodine production subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... iodine production subcategory. 415.430 Section 415.430 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Iodine Production Subcategory § 415.430 Applicability; description of the iodine production... iodine....

  8. 40 CFR 415.430 - Applicability; description of the iodine production subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... iodine production subcategory. 415.430 Section 415.430 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Iodine Production Subcategory § 415.430 Applicability; description of the iodine production... iodine....

  9. 40 CFR 415.430 - Applicability; description of the iodine production subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... iodine production subcategory. 415.430 Section 415.430 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Iodine Production Subcategory § 415.430 Applicability; description of the iodine production... iodine....

  10. Low-level seaweed supplementation improves iodine status in iodine-insufficient women.

    PubMed

    Combet, Emilie; Ma, Zheng Feei; Cousins, Frances; Thompson, Brett; Lean, Michael E J

    2014-09-14

    Iodine insufficiency is now a prominent issue in the UK and other European countries due to low intakes of dairy products and seafood (especially where iodine fortification is not in place). In the present study, we tested a commercially available encapsulated edible seaweed (Napiers Hebridean Seagreens® Ascophyllum nodosum species) for its acceptability to consumers and iodine bioavailability and investigated the impact of a 2-week daily seaweed supplementation on iodine concentrations and thyroid function. Healthy non-pregnant women of childbearing age, self-reporting low dairy product and seafood consumption, with no history of thyroid or gastrointestinal disease were recruited. Seaweed iodine (712 μg, in 1 g seaweed) was modestly bioavailable at 33 (interquartile range (IQR) 28-46) % of the ingested iodine dose compared with 59 (IQR 46-74) % of iodine from the KI supplement (n 22). After supplement ingestion (2 weeks, 0·5 g seaweed daily, n 42), urinary iodine excretion increased from 78 (IQR 39-114) to 140 (IQR 103-195) μg/l (P< 0·001). The concentrations of thyroid-stimulating hormone increased from 1·5 (IQR 1·2-2·2) to 2·1 (IQR 1·3-2·9) mIU/l (P< 0·001), with two participants having concentrations exceeding the normal range after supplement ingestion (but normal free thyroxine concentrations). There was no change in the concentrations of other thyroid hormones after supplement ingestion. The seaweed was palatable and acceptable to consumers as a whole food or as a food ingredient and effective as a source of iodine in an iodine-insufficient population. In conclusion, seaweed inclusion in staple foods would serve as an alternative to fortification of salt or other foods with KI. PMID:25006699

  11. Noise-immune laser receiver - transmitters with the quantum sensitivity limit

    SciTech Connect

    Kutaev, Yu F; Mankevich, S K; Nosach, O Yu; Orlov, E P

    2009-11-30

    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)

  12. First application of an online method for quantification of maritime molecular iodine and hypoiodic acid in maritime aerosol during PEGASO cruise

    NASA Astrophysics Data System (ADS)

    Götz, Sven; Dall'Osto, Manuel; Simó, Rafel; Hoffmann, Thosten

    2015-04-01

    The atmospheric chemistry of iodine is important in multiple ways. The focus lies on the ability to influence the oxidizing capacity of the atmosphere, i.e. by destruction of ozone, and the formation of iodine oxide particles (IOP), i.e. the influence on condensation nuclei (CCN). Using a variation of techniques, like differential optical absorption spectroscopy (DOAS), laser-induced fluorescence (LIF), inductively coupled plasma mass spectrometry (ICP-MS) and atmospheric pressure chemical ionization with tandem mass spectrometry (APCI-MS/MS), the reactive iodine species of atomic iodine (I), molecular iodine (I2), iodine monoxide (IO) and iodine dioxide (OIO) have all been detected in the atmosphere from Antarctica to the equatorial marine boundary layer (MBL). In the past few years there have been active research on IO, especially after revealing significant levels in open ocean measurements, and higher iodine oxides. In addition to atmospheric measurements, significant developments in laboratory kinetics, photochemistry and heterogeneous chemistry of iodine species have been accomplished. [1] Here we introduce the first field application of an online-method for detecting gaseous molecular iodine and HOI, which is a further development of a technique [2] based on selective photolytic dissociation, followed by oxidization and particle formation of iodine compounds. The particles are than size-segregated and detected by a scanning mobility particle sizer (SMPS) system. Initial IOP forming is performed in a reaction chamber providing specific wavelengths according to corresponding bond dissociation thresholds. Additionally offline sampling of iodine and iodine containing interhalogenes with coated diffusion denuders [3] were carried out throughout the cruise to compare both methods after analysis with GC/MS. Furthermore filter samples were taken to perform non-target analysis of organic compounds by UHPLC/ESI(+/-)-HR-MS. Preliminary results of iodine related analysis from the PEGASO cruise (plankton-derived emissions of trace gases and aerosols in the southern ocean) will be shown. [1] Saiz-Lopez, A.; Plane, J. M.C.; Baker, A. R.; Carpenter, L. J., von Glasow, R.; Gómez Martín, J. C.; McFiggans, G.; Saunders, R. W.; Chem. Rev., 2012, 112, 1773-1804 [2] MacDonald, S. M.; Gómez Martin, J. C.; Chance, R.; Warriner, S.; Saiz-Lopez, A.; Carpenter, L. J., Plane, J. M. C.; Atmos. Chem. Phys., 2014, 14, 5841-5852 [3] Huang, R. J.; Hoffmann, T.; Anal. Chemistry, 2009, 81, 1777-1783

  13. Risk of Suboptimal Iodine Intake in Pregnant Norwegian Women

    PubMed Central

    Brantsæter, Anne Lise; Abel, Marianne Hope; Haugen, Margaretha; Meltzer, Helle Margrete

    2013-01-01

    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 μg/day and 150 μg/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 μg/day from food and 166 μg/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 μg/day, 42.0% had iodine intake below 150 μg/day and only 21.7% reached the WHO/UNICEF/ICCIDD recommendation of 250 μg/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 μg/L) confirmed insufficient iodine intake. Public health strategies are needed to improve and secure the iodine status of pregnant women in Norway. PMID:23389302

  14. Milk and meat iodine content: relation to human health.

    PubMed

    Hemken, R W

    1980-05-15

    The amount of iodine consumed by human beings in the United States has increased over the past 10 to 15 years. Although there is no direct evidence of an increased human iodine toxicity problem because of the increased intake, there is some concern that if this trend continues, the greater iodine concentration may contribute to an increase in thyroid disorders. Because iodine content in milk has increased by 300% to 500% over the past 10 to 15 years, factors contributing to this increase have been studied. Organic iodine additions to the feed supply have contributed to large increases in iodine content in milk from some farms, and are considered the main factor contributing to the large increase in iodine content in milk values. Iodine teat dips and udder washes contribute to the increased iodine content of milk but generally do not result in increases of more than 150 micrograms/L. Iodine-sanitizing agents used on milking equipment or in milk transfer and storage equipment can contribute large amounts if improperly used, but the frequency of this problem is small. Iodine content in meat does increase with increased iodine intake, but the transfer of iodine to meat is relatively lower than it is to milk. PMID:7216884

  15. Iodine Supplementation: Usage with a Grain of Salt

    PubMed Central

    Prete, Alessandro; Corsello, Salvatore Maria

    2015-01-01

    Iodine supplementation through salt iodization is a worldwide, effective strategy for preventing iodine deficiency-related problems. Its safety and efficacy profile has been extensively investigated, and benefits far outweigh the potential iodine-induced risks. Moreover, iodine supplementation during pregnancy in order to avoid brain damage in the newborn is considered a mainstay of preventive medicine. Exposure to high amounts of iodine is actually well tolerated in most cases and can be unrecognized. Nevertheless, at-risk individuals may develop thyroid dysfunction even when they are exposed to increases in iodine intake universally considered as safe. Iodine-induced thyroid disorders include thyroid autoimmunity, thyrotoxicosis, iodine-induced goiter, and hypothyroidism. Moreover, a relationship between iodine intake and histotype distribution of differentiated thyroid cancer has been observed, with a progressive shift from follicular to papillary thyroid cancer. To date, evaluating iodine status in a clinical setting has limitations, and assessing the actual risk for each individual can be challenging, since it is influenced by personal history, genetics, and environmental factors. In conclusion, iodine supplementation programs need to be continued and strengthened, but iodine should be used with a grain of salt, because a growing number of susceptible individuals will be exposed to the risk of developing iodine-induced thyroid disorders. PMID:25873950

  16. Chamber studies of atmospheric iodine chemistry

    NASA Astrophysics Data System (ADS)

    Buxmann, J.; Njera, J.; Schmitt, S.; Bleicher, S.; Phler, D.; Horbanski, M.; Platt, U.; Zetzsch, C.; Bloss, W. J.

    2012-12-01

    Iodine chemistry has been shown to occur through much of the marine boundary layer (MBL). It leads to significant impacts upon atmospheric oxidising capacity, ozone levels and particle number concentration; however, there are major uncertainties in our knowledge of the iodine chemical reaction system, which limit our ability to accurately quantify these impacts using atmospheric models. In this work we report the results of novel atmospheric simulation chamber experiments, to study aspects of the fast gas-phase inorganic iodine oxide chemistry. We consider two specific issues here: First, in the presence of moderate levels of NO2, most current models predict that most active iodine should exist as INO3 (whose lifetime is controlled primarily by photolysis) and that levels of IO and OIO should be minimal. This is in contrast to observations from recent field measurements from semi-polluted coastal MBL locations which find significant levels of IO in the presence of NOx. Explanations include possible reactions of INO3 with I or O3 regenerating IO, or errors in the INO3 photochemical parameters. Second, while ozone loss is almost universally cited as a reason to study atmospheric iodine chemistry, calculations of the actual ozone destruction rate which results from a given iodine source term are rather uncertain - as we do not have quantitative understanding of the fate of the many potential iodine oxide species formed. This limits our ability to predict the steady state IO levels which will exist in equilibrium with a given iodine source term, and the resulting ozone loss rate. Recent field measurements in the MBL struggle to reconcile the observed IO with the measured iodine sources - indicating that additional sources exist, or alternatively that the model representation of the gas-phase iodine sink via higher iodine oxides is incorrect. We report the results from experiments performed in a 3.5 m3 indoor PTFE atmospheric simulation chamber located at BayCEER. Iodine species were produced from the controlled addition of a range of precursor molecules (I2, CH2I2, CH3I), photolysed using a solar simulator. I atoms and IO radicals were monitored using resonance fluorescence (the first such chamber measurements performed) and cavity-enhanced differential optical absorption spectroscopy, respectively. Experiments across a range of conditions were used to investigate the IOx-O3-NOx system. The data suggest that INO3 photolysis is rapid, dominating removal in the MBL and reducing the need for additional INO3 reactions to explain the field data, and determine the in situ chemical ozone removal rate resulting from a given iodine source strength / production rate. These results are considered in the context of previous laboratory and chamber studies, and their consequences for interpretation of atmospheric field data are discussed.

  17. Design of TEM00 mode side-pumped Nd:YAG solar laser

    NASA Astrophysics Data System (ADS)

    Almeida, Joana; Liang, Dawei

    2014-12-01

    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.

  18. Effect of iodine disinfection products on higher plants.

    PubMed

    Janik, D; Macler, B; Thorstenson, Y; Sauer, R; MacElroy, R D

    1989-01-01

    Iodine is used to disinfect potable water on United States spacecraft. Iodinated potable water will likely be used to grow plants in space. Little is known about the effects of iodine disinfection products on plants. Seeds of select higher plants were germinated in water iodinated using the Shuttle Microbial Check Valve, and water to which measured amounts of iodide was added. Percent germination was decreased in seeds of most species germinated in iodinated water. Beans were most affected. Germination rates, determined from germination half-times, were decreased for beans germinated in iodinated water, and water to which iodide was added. Development was retarded and rootlets were conspicuously absent in bean and several other plant species germinated in iodinated water. Iodide alone did not elicit these responses. Clearly iodine disinfection products can affect higher plants. These effects must be carefully considered for plant experimentation and cultivation in space, and in design and testing of closed environmental life support systems. PMID:11537380

  19. Iodination of organic compounds via organoborane intermediates: new methods

    SciTech Connect

    Gooch, E.E. III

    1981-01-01

    The incorporation of iodine into organic molecules can be accomplished through the use of organoboranes as synthetic intermediates. However, the iodination of organoboranes with molecular iodine is not suitable for the efficient incorporation of radioiodine into organic molecules since one-half of the radionuclide is lost as iodide. The iodination of organoboranes, vinylboronic acids and arylboronic acids was studied, using iodine monochloride or sodium iodide/chloramine-T. Both synthetic methods were rapid and efficient methods for iodinating organic substrates, including those with functional groups. The reactions provided maximum utilization of radioiodine in the synthesis of iodine-125 labeled compounds, both in preliminary tracer studies, and in experiments using carrier-free iodine-125.

  20. Effect of iodine disinfection products on higher plants

    NASA Astrophysics Data System (ADS)

    Janik, D.; Macler, B.; Thorstenson, Y.; Sauer, R.; MacElroy, R. D.

    Iodine is used to disinfect potable water on United States spacecraft. Iodinated potable water will likely be used to grow plants in space. Little is known about the effects of iodine disinfection products on plants. Seeds of select higher plants were germinated in water iodinated using the Shuttle Microbial Check Valve, and water to which measured amounts of iodide was added. Percent germination was decreased in seeds of most species germinated in iodinated water. Beans were most affected. Germination rates, determined from germination half-times, were decreased for beans germinated in iodinated water, and water to which iodide was added. Development was retarded and rootlets were conspicuously absent in bean and several other plant species germinated in iodinated water. Iodide alone did not elicit these responses. Clearly iodine disinfection products can affect higher plants. These effects must be carefully considered for plant experimentation and cultivation in space, and in design and testing of closed environmental life support systems.

  1. Iodine Propulsion Advantages for Low Cost Mission Applications and the Iodine Satellite (ISAT) Technology Demonstration

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.; Schumacher, Daniel M.

    2015-01-01

    The NASA Marshall Space Flight Center Science and Technology Office is continuously exploring technology options to increase performance or reduce cost and risk to future NASA missions including science and exploration. Electric propulsion is a prevalent technology known to reduce mission costs by reduction in launch costs and spacecraft mass through increased post launch propulsion performance. The exploration of alternative propellants for electric propulsion continues to be of interest to the community. Iodine testing has demonstrated comparable performance to xenon. However, iodine has a higher storage density resulting in higher ?V capability for volume constrained systems. Iodine's unique properties also allow for unpressurized storage yet sublimation with minimal power requirements to produce required gas flow rates. These characteristics make iodine an ideal propellant for secondary spacecraft. A range of mission have been evaluated with a focus on low-cost applications. Results highlight the potential for significant cost reduction over state of the art. Based on the potential, NASA has been developing the iodine Satellite for a near-term iodine Hall propulsion technology demonstration. Mission applications and progress of the iodine Satellite project are presented.

  2. Mode-locking in a laser with a coherent absorber

    NASA Astrophysics Data System (ADS)

    Arkhipov, M. V.; Arkhipov, R. M.; Shimko, A. A.; Babushkin, I.

    2015-02-01

    Mode-locking in a cw narrowband tunable dye laser whose cavity contains absorbing cells with molecular iodine vapor has been studied experimentally. When the wavelength of radiation of the dye laser is tuned to absorption lines of molecular iodine vapor in a cell in the cavity, short pulses following with a period equal to or multiple of the round-trip time of light around the cavity appear. The duration of the generated pulses is about 1 ns, which is much shorter than the phase memory time in iodine vapor. In such a situation, modelocking occurs owing to the coherent character of the interaction of laser radiation with narrow absorption resonances in molecular iodine vapor.

  3. The Ozone-Iodine-Chlorate Clock Reaction

    PubMed Central

    Sant'Anna, Rafaela T. P.; Monteiro, Emily V.; Pereira, Juliano R. T.; Faria, Roberto B.

    2013-01-01

    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

  4. Povidone iodine: features of critical systemic absorption.

    PubMed

    Lakhal, K; Faidherbe, J; Choukhi, R; Boissier, E; Capdevila, X

    2011-01-01

    Povidone iodine (PI), a skin antiseptic, is sometimes used internally but this procedure exposes to potentially lethal iodine absorption. Indeed, a 41-year-old woman, with no relevant medical history, developed a transient hypotension, anuric renal failure, hemolysis, coagulopathy and uterine infarction after intra-uterine injection of PI as a dye to check the fallopian tube patency (hydrotubation). Iodemia peaked at 6929 ?g/dL (normal range 3.4-8.0 ?g/dL), and decreased over the 9 days of renal replacement therapy. Extreme caution should be exercised when PI is in contact with a mucosa, the early recognition of iodine toxicity being of utmost importance to rapidly prompt renal replacement therapy. The main purpose of this report is to highlight the clinical features of PI absorption, whatever the route of administration. PMID:21680134

  5. The ozone-iodine-chlorate clock reaction.

    PubMed

    Sant'Anna, Rafaela T P; Monteiro, Emily V; Pereira, Juliano R T; Faria, Roberto B

    2013-01-01

    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

  6. [Iodine deficiency in infancy - a risk for cognitive development].

    PubMed

    Remer, T; Johner, S A; Gärtner, R; Thamm, M; Kriener, E

    2010-08-01

    Severe iodine deficiency during pregnancy seriously influences fetal brain development and in the worst case induces cretinism. Recent studies have shown that even a mild iodine deficiency during pregnancy and during the first years of life adversely affects brain development. The World Health Organisation (WHO) considers iodine deficiency as the most common preventable cause of early childhood mental deficiency. In this context, the insufficient production of the four iodine atoms containing thyroxine seems to play a causal role, i. e., due to the iodine substrate deficiency the neuronally particularly relevant free-thyroxine level falls. Due to the very limited iodine storage capacity, the infantile thyroid is eminently dependent on an adequate and steady iodine supply. In the first month of life, when milk is the only energy- and nutrient provider, infants fed a commercial formula regularly have a sufficient iodine supply. However, breastfed infants, who depend on maternal iodine status, frequently show an inadequate iodine intake. Furthermore, iodine intake is critical when complementary food (CF) is introduced. Especially homemade CF is poor in iodine, but also commercial CFs are only partly fortified. A simultaneous inadequate iodine supply of the breastfeeding mother and the preferential use of mostly iodine-poor organic milk cannot ensure an adequate iodine supply of the infant. In terms of an improvement of nutrient supply, especially concerning an unhindered brain development, the corresponding German reference value for iodine intake of infants until age 4 month should be raised from currently 40 microg/d to at least 60 microg/d (WHO-reference: 90 microg/d). PMID:20665419

  7. Iodine related grain growth in vapour deposited ZnS

    NASA Astrophysics Data System (ADS)

    Iwata, Hiroshi; Suzuki, Satoshi; Sasaki, Yasushi

    1992-12-01

    Large grain size ZnS crystals have been grown by CVD using H 2S, Zn vapour and a small amount of iodine gas. It was found that the grain size strongly depended on the partial pressure of iodine gas, but not the concentration of iodine in ZnS. The grain size is likely to be determined by the hydrogen content of ZnS, and the iodine's role is the removal of hydrogen from ZnS.

  8. Dynamics of production of iodine atoms by dissociation of iodides in a pulsed self-sustained discharge

    SciTech Connect

    Vagin, Nikolai P; Kochetov, Igor' V; Napartovich, A P; Yuryshev, Nikolai N

    2013-07-31

    Absorption at the laser transition has been used for the first time to assess the evolution of concentration of iodine atoms in a pulsed self-sustained discharge in mixtures of iodides with a buffer gas such as molecular nitrogen and helium. Dynamics of the iodine atom production is studied by the method of absorption spectroscopy. The dissociation of C{sub n}F{sub 2n+1}I and CnH{sub 2n+1}I (n = 1, 2) iodides is investigated. The energy required to produce atomic iodine is evaluated. The experimental data obtained for CF{sub 3}I are compared with the results of numerical simulations, their reasonable agreement being demonstrated. (active media)

  9. Particles and iodine compounds in coastal Antarctica

    NASA Astrophysics Data System (ADS)

    Roscoe, Howard K.; Jones, Anna E.; Brough, Neil; Weller, Rolf; Saiz-Lopez, Alfonso; Mahajan, Anoop S.; Schoenhardt, Anja; Burrows, John P.; Fleming, Zoe L.

    2015-07-01

    Aerosol particle number concentrations have been measured at Halley and Neumayer on the Antarctic coast, since 2004 and 1984, respectively. Sulphur compounds known to be implicated in particle formation and growth were independently measured: sulphate ions and methane sulphonic acid in filtered aerosol samples and gas phase dimethyl sulphide for limited periods. Iodine oxide, IO, was determined by a satellite sensor from 2003 to 2009 and by different ground-based sensors at Halley in 2004 and 2007. Previous model results and midlatitude observations show that iodine compounds consistent with the large values of IO observed may be responsible for an increase in number concentrations of small particles. Coastal Antarctica is useful for investigating correlations between particles, sulphur, and iodine compounds, because of their large annual cycles and the source of iodine compounds in sea ice. After smoothing all the measured data by several days, the shapes of the annual cycles in particle concentration at Halley and Neumayer are approximated by linear combinations of the shapes of sulphur compounds and IO but not by sulphur compounds alone. However, there is no short-term correlation between IO and particle concentration. The apparent correlation by eye after smoothing but not in the short term suggests that iodine compounds and particles are sourced some distance offshore. This suggests that new particles formed from iodine compounds are viable, i.e., they can last long enough to grow to the larger particles that contribute to cloud condensation nuclei, rather than being simply collected by existing particles. If so, there is significant potential for climate feedback near the sea ice zone via the aerosol indirect effect.

  10. [Overall child development: beyond pharmacological iodine supplementation].

    PubMed

    Gaviln, Enrique; Jimnez de Gracia, Laura

    2013-12-01

    Iodine deficiency is a factor that may compromise child development, but is not the only one. Other health determinants, some of them outside the healthcare system, are able to influence development. Fighting iodine deficiency may be a pragmatic and useful strategy if it is found to be not maleficent, beneficial to health, and cost-effective, and does not make us lose the notion that child development goes beyond psychomotor or cognitive performance. This article analyzes such constraints from a critical point of view. PMID:23916171

  11. Iododerma following topical povidone-iodine application.

    PubMed

    Aliagaoglu, Cihangir; Turan, Hakan; Uslu, Esma; Albayrak, Hulya; Yazici, Serkan; Kaya, Ertugrul

    2013-10-01

    A 43-year-old male patient presented with two well-demarcated, elevated plaques, measuring 4?cm in diameter, with yellow-black crusts over it that appeared 3?d earlier. With the help of history, physical examination and histopathological features, the patient was diagnosed with iododerma secondary to topical povidone-iodine use. Iododerma develops frequently after oral or intravenous but rarely after topical use of iodine. Its pathogenesis is not well-known though it is widely believed that it is a delayed hypersensitivity reaction. PMID:23560395

  12. Facile Oxidative Rearrangements Using Hypervalent Iodine Reagents

    PubMed Central

    Singh, Fateh V; Rehbein, Julia; Wirth, Thomas

    2012-01-01

    Aromatic substituents migrate in a novel oxidative cyclization mediated by iodine(III) reagents. 4-Arylbut-3-enoic acids are cyclized and rearranged to 4-arylfuran-2(5H)-ones by hypervalent iodine compounds in good to excellent yields under mild reaction conditions. Other ring sizes are also accessible. The mechanism of the reaction is described in detail, and calculations highlight the cationic nature of the intermediates in the rearrangement. The fast access to heavily substituted furanones is used for the synthesis of biologically active derivatives. PMID:24551514

  13. Regenerable Iodine Water-Disinfection System

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L.; Colombo, Gerald V.; Jolly, Clifford D.

    1994-01-01

    Iodinated resin bed for disinfecting water regenerated to extend its useful life. Water flows through regeneration bed of crystalline iodine during regeneration. At other times, flow diverted around regeneration bed. Although regeneration cycle was manually controlled in demonstration, readily automated to start and stop according to signals and stop according to signals from concentration sensors. Further benefit of regeneration is that regeneration bed provides highly concentrated biocide source (200 mg/L) when needed. Concentrated biocide used to superiodinate system after contamination from routine maintenance or unexpected introduction of large concentration of microbes.

  14. A quantitative model of the biogeochemical transport of iodine

    NASA Astrophysics Data System (ADS)

    Weng, H.; Ji, Z.; Weng, J.

    2010-12-01

    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.

  15. Vitamin E ameliorates iodine-induced cytotoxicity in thyroid.

    PubMed

    Yu, Jiashu; Shan, Zhongyan; Chong, Wei; Mao, Jinyuan; Geng, Yuxiu; Zhang, Caixia; Xing, Qian; Wang, Weiwei; Li, Ningna; Fan, Chenling; Wang, Hong; Zhang, Hongmei; Teng, Weiping

    2011-06-01

    Acute and excessive iodine supplementation leads to iodine-induced thyroid cytotoxicity. Excessive oxidative stress has been suggested to be one of the underlying mechanisms in the development of thyroid cytotoxicity. The aim of this study was to investigate whether vitamin E (VE), an important antioxidant, could ameliorate iodine-induced thyroid cytotoxicity. A goiter was induced in rats by feeding a low-iodine (LI) diet for 12 weeks. Involution of hyperplasia was obtained by administering a twofold physiological dose of iodine in feeding water with/without the supplementation of 25-, 50-, or 100-fold physiological dose of VE in the LI diet for 4 weeks. In iodine-supplemented rats, thyroid epithelial cell ultrastructure injuries remained and were more severe. Relative weights of iodine-induced involuting glands were significantly reduced compared with the goiter, but still higher than control. Immunohistochemistry indicated that the expression of 4-hydroxynonenal, 8-hydroxyguanine, peroxiredoxin 5, and CD68 in thyroid increased (P<0.01), whereas thioredoxin reductase 1 decreased (P<0.01). VE supplementation attenuated thyroid cytotoxicity induced by iodine. A 50-fold VE dose was optimal in attenuating twofold iodine-induced thyroid cytotoxicity. However, VE supplementation did not reduce the weight or relative weight of the iodine-induced involuting gland. These results show that excess iodine leads to thyroid damage and VE supplementation can partly ameliorate iodine-induced thyroid cytotoxicity. PMID:21406454

  16. Tomato fruits: a good target for iodine biofortification

    PubMed Central

    Kiferle, Claudia; Gonzali, Silvia; Holwerda, Harmen T.; Ibaceta, Rodrigo Real; Perata, Pierdomenico

    2013-01-01

    Iodine is a trace element that is fundamental for human health: its deficiency affects about two billion people worldwide. Fruits and vegetables are usually poor sources of iodine; however, plants can accumulate iodine if it is either present or exogenously administered to the soil. The biofortification of crops with iodine has therefore been proposed as a strategy for improving human nutrition. A greenhouse pot experiment was carried out to evaluate the possibility of biofortifying tomato fruits with iodine. Increasing concentrations of iodine supplied as KI or KIO3 were administered to plants as root treatments and the iodine accumulation in fruits was measured. The influences of the soil organic matter content or the nitrate level in the nutritive solution were analyzed. Finally, yield and qualitative properties of the biofortified tomatoes were considered, as well as the possible influence of fruit storage and processing on the iodine content. Results showed that the use of both the iodized salts induced a significant increase in the fruit’s iodine content in doses that did not affect plant growth and development. The final levels ranged from a few mg up to 10 mg iodine kg - 1 fruit fresh weight and are more than adequate for a biofortification program, since 150 μg iodine per day is the recommended dietary allowance for adults. In general, the iodine treatments scarcely affected fruit appearance and quality, even with the highest concentrations applied. In contrast, the use of KI in plants fertilized with low doses of nitrate induced moderate phytotoxicity symptoms. Organic matter-rich soils improved the plant’s health and production, with only mild reductions in iodine stored in the fruits. Finally, a short period of storage at room temperature or a 30-min boiling treatment did not reduce the iodine content in the fruits, if the peel was maintained. All these results suggest that tomato is a particularly suitable crop for iodine biofortification programs. PMID:23818889

  17. Laser-powered lunar base

    NASA Technical Reports Server (NTRS)

    Costen, R.; Humes, Donald H.; Walker, G. H.; Williams, M. D.; Deyoung, Russell J.

    1989-01-01

    The objective was to compare a nuclear reactor-driven Sterling engine lunar base power source to a laser-to-electric converter with orbiting laser power station, each providing 1 MW of electricity to the lunar base. The comparison was made on the basis of total mass required in low-Earth-orbit for each system. This total mass includes transportation mass required to place systems in low-lunar orbit or on the lunar surface. The nuclear reactor with Sterling engines is considered the reference mission for lunar base power and is described first. The details of the laser-to-electric converter and mass are discussed. The next two solar-driven high-power laser concepts, the diode array laser or the iodine laser system, are discussed with associated masses in low-lunar-orbit. Finally, the payoff for laser-power beaming is summarized.

  18. Source And Sink Of Iodine For Drinking Water

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  19. Dry method for recycling iodine-loaded silver zeolite

    DOEpatents

    Thomas, Thomas R.; Staples, Bruce A.; Murphy, Llewellyn P.

    1978-05-09

    Fission product iodine is removed from a waste gas stream and stored by passing the gas stream through a bed of silver-exchanged zeolite until the zeolite is loaded with iodine, passing dry hydrogen gas through the bed to remove the iodine and regenerate the bed, and passing the hydrogen stream containing the hydrogen iodide thus formed through a lead-exchanged zeolite which adsorbs the radioactive iodine from the gas stream and permanently storing the lead-exchanged zeolite loaded with radioactive iodine.

  20. Iodine deficiency: consequences and progress toward elimination.

    PubMed

    Maberly, Glen F; Haxton, David P; van der Haar, Frits

    2003-12-01

    While traditionally associated with cretinism and goiter, iodine deficiency has broad effects on central nervous system development that can occur in the absence of either condition. Any maternal iodine deficiency results in a range of intellectual, motor, and hearing deficits in offspring. This loss in intellectual capacity limits educational achievement of populations and the economic prowess of nations. Progress made since the historic World Summit for Children in 1990 has been outstanding. Approximately 70% of households in the world used iodized salt by 2000, compared with less than 20% in 1990. It is estimated that at least 85 million newborns out of 130 million annual births are protected from a loss in learning ability that would otherwise have occurred. The elimination of iodine deficiency, by expedient production, marketing, and universal consumption of iodized salt, represents a significant development effort in public nutrition. Although globally iodine nutrition has greatly improved, 20% to 30% of pregnancies and thus newborns still do not fully benefit from the use of iodized salt. Countries where success is in evidence could rapidly revert back to deficiency if vigilance is not maintained. Just as success came through concerted public-private-civic actions, making sure that this is expanded and will steadily go on requires continuous collaboration. PMID:17016950

  1. Iodine retention during evaporative volume reduction

    DOEpatents

    Godbee, H.W.; Cathers, G.I.; Blanco, R.E.

    1975-11-18

    An improved method for retaining radioactive iodine in aqueous waste solutions during volume reduction is disclosed. The method applies to evaporative volume reduction processes whereby the decontaminated (evaporated) water can be returned safely to the environment. The method generally comprises isotopically diluting the waste solution with a nonradioactive iodide and maintaining the solution at a high pH during evaporation.

  2. METHOD OF REMOVING RADIOACTIVE IODINE FROM GASES

    DOEpatents

    Silverman, L.

    1962-01-23

    A method of removing radioactive iodine from a gaseous medium is given in which the gaseous medium is adjusted to a temperature not exceeding 400 deg C and then passed over a copper fibrous pad having a coating of cupric sulfide deposited thereon. An ionic exchange on the pad results in the formation of cupric iodide and the release of sulfur. (AEC)

  3. Iodine as propellant for electric space propulsion

    NASA Astrophysics Data System (ADS)

    Grondein, Pascaline; Chabert, Pascal; Aanesland, Ane

    2014-10-01

    In PEGASES (an electric gridded thruster) both positive and negative ions are expelled after extraction from an ion-ion plasma formed downstream a localized magnetic field placed a few centimeters from the ionization region. For this thruster concept, we believe that Iodine is the best candidate. Its advantages are multiple: heavy and therefore good for high thrust, low ionization threshold and high electronegativity (the latter crucial for PEGASES) leading to high ion-ion densities and low RF power, at solid state at STP with a high vapor, and finally inexpensive. Iodine is also di-atomic and therefore energy loss in dissociation processes are reduced compared to SF6. We present here a dedicated experimental set-up intended for iodine experiments. The injection system consists of an evaporation chamber with temperature controlled gas lines and vacuum chamber to control condensation. A global model of the iodine electronegative plasma will be developed to compare and predict the plasma behavior and composition inside the thruster. The main challenge in this model is to reproduce the conditions of a strongly segregated plasma with two regions: one with rather high electron temperature and low electronegativity and the other an ion-ion plasma with low temperature.

  4. Arthur von Hubl and the Iodine Value

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The iodine value is still one of the most commonly applied indices in fatty acid chemistry. Its introduction was a milestone in analyzing fats and oils as well as describing their structure-property relationships, although it can be considered largely outdated because modern analytical methods such...

  5. Photoionization of atomic iodine and atomic tellurium

    SciTech Connect

    Berkowitz, J.; Batson, C.H.; Goodman, G.L.

    1980-01-01

    The photoionization yield curve is presented for atomic iodine from 645 A to the ionization threshold, made using a thermal atomic beam source and photoionization mass spectrometry. This information is also presented for tellurium from 670 A to the ionization threshold.

  6. Radioactive iodine separations and waste forms development.

    SciTech Connect

    Krumhansl, James Lee; Nenoff, Tina Maria; Garino, Terry J.; Rademacher, David

    2010-04-01

    Reprocessing nuclear fuel releases gaseous radio-iodine containing compounds which must be captured and stored for prolonged periods. Ag-loaded mordenites are the leading candidate for scavenging both organic and inorganic radioiodine containing compounds directly from reprocessing off gases. Alternately, the principal off-gas contaminant, I2, and I-containing acids HI, HIO3, etc. may be scavenged using caustic soda solutions, which are then treated with bismuth to put the iodine into an insoluble form. Our program is focused on using state-of-the-art materials science technologies to develop materials with high loadings of iodine, plus high long-term mechanical and thermal stability. In particular, we present results from research into two materials areas: (1) zeolite-based separations and glass encapsulation, and (2) in-situ precipitation of Bi-I-O waste forms. Ag-loaded mordenite is either commercially available or can be prepared via a simple Ag+ ion exchange process. Research using an Ag+-loaded Mordenite zeolite (MOR, LZM-5 supplied by UOP Corp.) has revealed that I2 is scavenged in one of three forms, as micron-sized AgI particles, as molecular (AgI)x clusters in the zeolite pores and as elemental I2 vapor. It was found that only a portion of the sorbed iodine is retained after heating at 95o C for three months. Furthermore, we show that even when the Ag-MOR is saturated with I2 vapor only roughly half of the silver reacted to form stable AgI compounds. However, the Iodine can be further retained if the AgI-MOR is then encapsulated into a low temperature glass binder. Follow-on studies are now focused on the sorption and waste form development of Iodine from more complex streams including organo-iodine compounds (CH3I). Bismuth-Iodate layered phases have been prepared from caustic waste stream simulant solutions. They serve as a low cost alternative to ceramics waste forms. Novel compounds have been synthesized and solubility studies have been completed using competing groundwater anions (HCO3-, Cl- and SO42-). Distinct variations in solubility were found that related to the structures of the materials.

  7. Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.

    PubMed

    Gong, Tingting; Zhang, Xiangru

    2013-11-01

    The dissolved iodine species that dominate aquatic systems are iodide, iodate and organo-iodine. These species may undergo transformation to one another and thus affect the formation of iodinated disinfection byproducts during disinfection of drinking waters or wastewater effluents. In this study, a fast, sensitive and accurate method for determining these iodine species in waters was developed by derivatizing iodide and iodate to organic iodine and measuring organic iodine with a total organic iodine (TOI) measurement approach. Within this method, organo-iodine was determined directly by TOI measurement; iodide was oxidized by monochloramine to hypoiodous acid and then hypoiodous acid reacted with phenol to form organic iodine, which was determined by TOI measurement; iodate was reduced by ascorbic acid to iodide and then determined as iodide. The quantitation limit of organo-iodine or sum of organo-iodine and iodide or sum of organo-iodine, iodide and iodate was 5 ?g/L as I for a 40 mL water sample (or 2.5 ?g/L as I for an 80 mL water sample, or 1.25 ?g/L as I for a 160 mL water sample). This method was successfully applied to the determination of iodide, iodate and organo-iodine in a variety of water samples, including tap water, seawater, urine and wastewater. The recoveries of iodide, iodate and organo-iodine were 91-109%, 90-108% and 91-108%, respectively. The concentrations and distributions of iodine species in different water samples were obtained and compared. PMID:24075720

  8. A Review: Radiographic Iodinated Contrast Media-Induced Thyroid Dysfunction

    PubMed Central

    Leung, Angela M.; Braverman, Lewis E.; Brent, Gregory A.; Pearce, Elizabeth N.

    2015-01-01

    Context: Thyroid hormone production is dependent on adequate iodine intake. Excess iodine is generally well-tolerated, but thyroid dysfunction can occur in susceptible individuals after excess iodine exposure. Radiological iodinated contrast media represent an increasingly common source of excess iodine. Objective: This review will discuss the thyroidal response after acute exposure to excess iodine; contrast iodine-induced thyroid dysfunction; risks of iodine-induced thyroid dysfunction in vulnerable populations, such as the fetus, neonate, and patients with impaired renal function; and recommendations for the assessment and treatment of contrast iodine-induced thyroid dysfunction. Methods: Data for this review were identified by searching PubMed, Google Scholar, and references from relevant articles from 1948 to 2014. Conclusions: With the increase in the use of computed tomography scans in the United States, there is increasing risk of contrast-induced thyroid dysfunction. Patients at risk of developing iodine-induced thyroid dysfunction should be closely monitored after receiving iodinated contrast media and should be treated as needed. PMID:25375985

  9. Adsorption properties of iodine-doped activated carbon fiber.

    PubMed

    Yang, Cheol-Min; Kaneko, Katsumi

    2002-02-01

    Iodine-doped activated carbon fibers (ACFs) were prepared by the iodine immersion method on pitch-based ACF. Then iodine-doped ACFs were heated in argon at 523 K for 4 h and at 673 K for 2 h. The iodine structure of the resultant iodine-doped ACFs was examined using X-ray photoelectron spectroscopy. The micropore structures were determined by N(2) adsorption at 77 K. The surface area and micropore volume of iodine-doped ACFs are less than those of pristine ACFs. However, the pore width does not change with the iodine doping. The effects of iodine doping on adsorption properties of ACFs for H(2)O and NO at 303 K were examined. The iodine doping affected remarkably the adsorptivities of ACFs for H(2)O and NO. In particular, iodine-doped ACFs treated at 673 K show enhanced adsorptivities for H(2)O and NO. This result suggests that iodine molecules doped on the micropores should be charged by heat treatment at 673 K. PMID:16290381

  10. [Effect and effectiveness of iodine brine baths in a spa].

    PubMed

    Eichler, I; Winkler, R

    1994-01-01

    On the occasion of closing the research department of the Paracelsus Institute in the iodine salt spa, Bad Hall, the results of more than 30 years' research work in this institute are summarized. This work concerned the therapeutic effects of iodine on circulatory illnesses, especially hypertension, bronchitis and degenerative eye diseases. Controlled studies in patients showed significant cure effects of the iodine springs. Other studies demonstrated an influence of iodine on peripheral blood vessels, blood viscosity, connective tissue and vision and demonstrated the scavenger function of iodine, too. The different therapeutic forms of iodine administration (baths, sprays, iontophoresis, drinking cures) are described and the potential side effects of a cure in an iodine spa, notably temporary hypothyroidism, are mentioned. PMID:8023520

  11. Additional studies for the spectrophotometric measurement of iodine in water

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Previous work in iodine spectroscopy is briefly reviewed. Continued studies of the direct spectrophotometric determination of aqueous iodine complexed with potassium iodide show that free iodine is optimally determined at the isosbestic point for these solutions. The effects on iodine determinations of turbidity and chemical substances (in trace amounts) is discussed and illustrated. At the levels tested, iodine measurements are not significantly altered by such substances. A preliminary design for an on-line, automated iodine monitor with eventual capability of operating also as a controller was analyzed and developed in detail with respect single beam colorimeter operating at two wavelengths (using a rotating filter wheel). A flow-through sample cell allows the instrument to operate continuously, except for momentary stop flow when measurements are made. The timed automatic cycling of the system may be interrupted whenever desired, for manual operation. An analog output signal permits controlling an iodine generator.

  12. Metabolic engineering of the iodine content in Arabidopsis

    PubMed Central

    Landini, Martina; Gonzali, Silvia; Kiferle, Claudia; Tonacchera, Massimo; Agretti, Patrizia; Dimida, Antonio; Vitti, Paolo; Alpi, Amedeo; Pinchera, Aldo; Perata, Pierdomenico

    2012-01-01

    Plants are a poor source of iodine, an essential micronutrient for human health. Several attempts of iodine biofortification of crops have been carried out, but the scarce knowledge on the physiology of iodine in plants makes results often contradictory and not generalizable. In this work, we used a molecular approach to investigate how the ability of a plant to accumulate iodine can be influenced by different mechanisms. In particular, we demonstrated that the iodine content in Arabidopsis thaliana can be increased either by facilitating its uptake with the overexpression of the human sodium-iodide symporter (NIS) or through the reduction of its volatilization by knocking-out HOL-1, a halide methyltransferase. Our experiments show that the iodine content in plants results from a balance between intake and retention. A correct manipulation of this mechanism could improve iodine biofortification of crops and prevent the release of the ozone layer-threatening methyl iodide into the atmosphere. PMID:22468225

  13. Iodine Revolatilization in a Grand Gulf Loca

    SciTech Connect

    Beahm, E.C.; Weber, C.F.

    1999-01-01

    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.

  14. A rate equation approach to gain saturation effects in laser mode calculations

    NASA Technical Reports Server (NTRS)

    Roberts, Lila F.

    1990-01-01

    Space exploration and research require large amounts of power. Solar pumped laser systems have been shown to have the potential for meeting the performance requirements necessary for power transmission in space. The successful design of laser systems for these applications will depend, in part, on having a clear understanding of the development of the dynamical processes in the laser cavity and on the effects that changes in physical and design parameters have on laser performance. In particular, it is necessary to know the amplitude and phase distributions of the laser beam at the output aperture when steady state operation is achieved in order to determine the far-field power distribution. The output from the laser will depend on the active medium, the optical environment of the active material and on the gain distribution in the active region as laser action builds up and reaches steady state. An important component in the design process will be a realistic model of the active laser cavity. A computer model of the laser cavity, based on Huygens' principle was developed. The code calculates the amplitude and phase of an optical wave reflected back and forth between the mirrors of a laser cavity. The original code assumes a gain distribution which does not change with the buildup of oscillations in the cavity. A step in the direction of realism is the inclusion of a saturable gain medium in the cavity. The objective is to incorporate saturation effects into the existing computer model.

  15. Long-term migration of iodine in sedimentary rocks based on iodine speciation and 129I/127I ratio

    NASA Astrophysics Data System (ADS)

    Togo, Y.; Takahashi, Y.; Amano, Y.; Matsuzaki, H.; Suzuki, Y.; Muramatsu, Y.; Iwatsuki, T.

    2012-12-01

    [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.

  16. Iodine excretion has decreased in Denmark between 2004 and 2010--the importance of iodine content in milk.

    PubMed

    Rasmussen, Lone B; Carl, Allan; Jrgensen, Torben; Knuthsen, Pia; Krejbjerg, Anne; Perrild, Hans; Bjergved, Lena; Sloth, Jens J; Laurberg, Peter; Ovesen, Lars

    2014-12-28

    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

  17. Development and validation of an iodine-specific FFQ to estimate iodine intake in Australian pregnant women.

    PubMed

    Condo, Dominique; Makrides, Maria; Skeaff, Sheila; Zhou, Shao J

    2015-03-28

    Adequate iodine is important during pregnancy to ensure optimal growth and development of the offspring. We validated an iodine-specific FFQ (I-FFQ) for use in Australian pregnant women. A forty-four-item I-FFQ was developed to assess iodine intake from food and was administered to 122 pregnant women at 28 weeks gestation. Iodine supplement use was captured separately at 28 weeks gestation. Correlation between iodine intake from food estimated using the I-FFQ and a 4 d weighed food record as well as correlation between total iodine intake and 24 h urinary iodine excretion (UIE), 24 h urinary iodine concentration (UIC), spot UIC and thyroid function were assessed at 28 weeks gestation. A moderate correlation between the two dietary methods was shown (r 0349, P< 0001), and it was strengthened with the addition of iodine supplements (r 0876, P<0001). There was a fair agreement (k= 028, P<0001) between the two dietary measures in the classification of women as receiving adequate (?160 ?g/d) or inadequate (<160 ?g/d) iodine intake from food, but the limits of agreement from the Bland-Altman plot were large. Total iodine intake was associated with 24 h UIE (? = 0488, P<0001) but not with spot UIC. Iodine intake from food using the I-FFQ was assessed at study entry (<20 weeks gestation) in addition to 28 weeks gestation, and there was a strong correlation in iodine intake at the two time points (r 0622, P<0001), which indicated good reproducibility. In conclusion, the I-FFQ provides a valid tool for estimating iodine intake in pregnant women and can be used to screen women who are at risk of inadequate intake. PMID:25744430

  18. Quantification of total iodine in intact granular starches of different botanical origin exposed to iodine vapor at various water activities.

    PubMed

    Manion, Bruce; Ye, Mei; Holbein, Bruce E; Seetharaman, Koushik

    2011-11-01

    Iodine has been used as an effective tool for studying both the structure and composition of dispersed starch and starch granules. In addition to being employed to assess relative amylose contents for starch samples, it has been used to look at the molecular mobility of the glucose polymers within intact starch granules based on exposure to iodine vapor equilibrated at different water activities. Starches of different botanical origin including corn, high amylose corn, waxy corn, potato, waxy potato, tapioca, wheat, rice, waxy rice, chick pea and mung bean were equilibrated to 0.33, 0.75, 0.97 water activities, exposed to iodine vapor and then absorbance spectra and LAB color were determined. In addition, a new iodine quantification method sensitive to <0.1% iodine (w/w) was employed to measure bound iodine within intact granular starch. Amylose content, particle size distribution of granules, and the density of the starch were also determined to explore whether high levels of long linear glucose chains and the surface area-to-volume ratio were important factors relating to the granular iodine binding. Results showed, in all cases, starches complexed more iodine as water content increased and waxy starches bound less iodine than their normal starch counterparts. However, much more bound iodine could be measured chemically with waxy starches than was expected based on colorimetric determination. Surface area appeared to be a factor as smaller rice and waxy rice starch granules complexed more iodine, while the larger potato and waxy potato granules complexed less than would be expected based on measured amylose contents. Corn, high amylose corn, and wheat, known to have starch granules with extensive surface pores, bound higher levels of iodine suggesting pores and channels may be an important factor giving iodine vapor greater access to bind within the granules. Exposing iodine vapor to moisture-equilibrated native starches is an effective tool to explore starch granule architecture. PMID:21962455

  19. Laboratory studies on tropospheric iodine chemistry: bridging the atomic, molecular and particle scale

    NASA Astrophysics Data System (ADS)

    Gomez Martin, J.; Saunders, R. W.; Blitz, M. A.; Mahajan, A. S.; Plane, J. M.

    2008-12-01

    High mixing ratios of the iodine oxides IO and OIO have been observed in the polar, mid-latitude and tropical marine boundary layer (MBL). The impact of the iodine chemistry on the oxidizing capacity of the MBL is well documented. Moreover, there is evidence showing that the bursts of new particles measured in coastal regions are produced by the biogenic emission of iodine containing precursors, followed by the photochemical production and condensation of iodine oxide vapours. Airborne measurements of particle growth rates show that these particles can reach significant sizes where they can contribute to the regional aerosol loading, thus suggesting a potential impact on climate on a regional or global scale. Within the frame of the INSPECT project (INorganic Secondary Particle Evolution, Chemistry and Transport) we wish to understand at a fundamental level the tendency for the iodine oxides formed from IO and OIO recombination to condense into particles. Elemental analysis of iodine oxide particles (IOP) made in the laboratory shows that they have the empirical formula I2O5. The major question is how this happens: through formation of I2O5 in the gas phase, followed by polymerization, or by condensation of various IxOy to form amorphous iodine oxides, which subsequently rearrange to I2O5. We are studying the gas phase photochemistry leading to nucleation of IOP, their growth kinetics, aspects of their heterogeneous chemistry, and their properties as ice condensation nuclei. In order to bridge the molecular and the particle scales, a wide variety of techniques are being used, including CRDS, ARAS, LIF, UV-VIS spectroscopy, PI-TOF-MS and mobility particle size scanning. The results obtained so far provide new and interesting insights to the problem. From the gas phase point of view, a unit iodine atom quantum yield from OIO photolysis has been now established across its strong visible spectral bands. This result implies a short lifetime of OIO and explains why in general it could not be observed during daytime in the field. This is also consistent with recently observed ozone depletion events possibly correlated to high concentrations of IO. On the other hand, atmospheric modelling shows that the rate of formation of condensable iodine vapours decreases when a high OIO photolysis rate is considered, although the modelled values are still consistent with the rates of particle formation observed in the MBL. On the particle scale, the role of water and sulphuric acid vapour uptake on the formation and growth of IOP has been studied by analysis of the observed changes to measured particle size distribution data. In the case of water, hygroscopic growth factors have been determined at different ambient relative humidities, while for H2SO4 the uptake coefficient onto IOP has been evaluated. The experimental data suggests the possibility of a ternary nucleation route involving iodine oxide-water-acid vapours. Currently, pulsed laser photolysis coupled to PI-TOF-MS is being used to study the transition regime between the gas and particle phase. With this technique it is possible to resolve small clusters up to 1200 amu with sufficient resolution to determine, e.g., whether I2O4 or I2O5 is the condensable unit of IOP.

  20. Reaction of gaseous mercury with molecular iodine, atomic iodine, and iodine oxide radicals - Kinetics, product studies, and atmospheric implications

    NASA Astrophysics Data System (ADS)

    Raofie, F.; Snider, G.; Ariya, P.

    2008-12-01

    Mercury is present in the Earth's atmosphere mainly in elemental form. The chemical transformation of mercury in the atmosphere may influence its bioaccumulation in the human food chain as well as its global cycling. We carried out the first kinetic and product studies of the reactions of gaseous mercury with molecular iodine, atomic iodine, and iodine oxide radicals at tropospheric pressure (similar to 740 Torr) and 296 2 K in air and in N2 (1 Torr = 133.3 Pa). Atomic iodine was formed using UV photolysis of CH2I2. IO radicals were formed by the UV photolysis of CH2I2 in the presence of ozone The reaction kinetics were studied using absolute rate techniques with gas chromatographic and mass spectroscopic detection (GC-MS). The measured rate coefficient for the reaction of Hg{0} with I2 was < (1.27 0.58) 10-19 cm3 molecule-1 s-1. The reaction products were analyzed in the gas phase from the suspended aerosols and from deposits on the walls of the reaction chambers using six complementary methods involving chemical ionization and electron impact mass spectrometry, GC-MS, a MALDI-TOF mass spectrometer, a cold vapor atomic fluorescence spectrometer (CVAFS), and a high-resolution transmission electron microscope (HRTEM) coupled to an energy dispersive spectrometer (EDS). The major reaction products identified were HgI2, HgO, and HgIO or HgOI. The implications of the results are discussed with regards to both the chemistry of atmospheric mercury and its potential implications in the biogeochemical cycling of mercury.

  1. Iodine-xenon studies and the relax mass spectrometer

    NASA Astrophysics Data System (ADS)

    Gilmour, J. D.; Ash, R. D.; Lyon, I. C.; Johnston, W. A.; Hutchison, R.; Bridges, J. C.; Turner, G.

    1994-07-01

    RELAX combines a resonance ionization ion source with a cryogenic sample concentrator to achieve ultrasensitivity. Gas is extracted from samples using either a continuous wave laser microprobe based on an argon-ion laser or a filament microfurnace. Recent refinements in the operating procedure have resulted in optimum sensitivities such that detection rates of 1 cps are achieved from fewer than 500 atoms. A Xe-128 spike reservoir has also been added and characterized, allowing accurate determinations of absolute amounts of gas. We have completed a preliminary study of the iodine-xenon system in samples from the Bjurbole and Parnallee meteorites. Bjurbole chondrules ranging in mass from 5.45 mg to 260 micrograms were analyzed by laser microprobe. The results from these samples are consistent with an effectively uniform formation age, suggesting that the use of Bjurbole chondrules for calibration of this chronometer can be extended to samples in this size range. Samples from two chondrules from the Parnallee meteorite have been analyzed to date. An alpha-cristobalite-bearing chondrule (designated CB1) was found to have a formation age 4.62 +/- 0.44 Ma after Bjurboele, while a porphyritic olivine macrochondrule appears to have been reset after the decay of I-129(t1/2 17 Ma). Consideration of these results alongside Ar-Ar data from the macrochondrule and whole rock samples suggests that Parnallee has a complex history: The macrochondrule underwent an early postcrystallization degassing event but appears to have been essentially unaffected by the later (1.9 Ga) partial resetting of the bulk meteorite.

  2. Stabilisation of microalgae: Iodine mobilisation under aerobic and anaerobic conditions.

    PubMed

    Han, Wei; Clarke, William; Pratt, Steven

    2015-10-01

    Mobilisation of iodine during microalgae stabilisation was investigated, with the view of assessing the potential of stabilised microalgae as an iodine-rich fertiliser. An iodine-rich waste microalgae (0.35 0.05 mg I g(-1) VS(added)) was stabilised under aerobic and anaerobic conditions. Iodine mobilisation was linearly correlated with carbon emission, indicating iodine was in the form of organoiodine. Comparison between iodine and nitrogen mobilisation relative to carbon emission indicated that these elements were, at least in part, housed separately within the cells. After stabilisation, there were 0.22 0.05 and 0.19 0.01 mg g(-1) VS(added) iodine remaining in the solid in the aerobic and anaerobic processed material respectively, meaning 38 5.0% (aerobic) and 50 8.6% (anaerobic) of the iodine were mobilised, and consequently lost from the material. The iodine content of the stabilised material is comparable to the iodine content of some seaweed fertilisers, and potentially satisfies an efficient I-fertilisation dose. PMID:26141281

  3. Safety of iodine based water sterilization for travelers.

    PubMed

    Goodyer, L; Behrens, R H

    2000-01-01

    The recent report by Khan et al. of an unexpectedly high concentration of free iodine in water filters, which may have led to the high proportion of abnormal thyroid function tests in Peace Corps workers, is of concern for travel advisors when asked to recommend suitable means of water sterilization. Many travelers use iodine based filters and/or chemicals for purification of water when traveling in areas with contaminated water supplies and may therefore be at risk of excess iodine intake. Aside from iodine impregnated resin filtration systems, tetraglycine hydroperiodide tablets, tincture of iodine 2% and more commonly, chlorine-based proprietary products are widely used to sterilize water for drinking, and usually purchased by travelers without advice on how they should be used. A single tetraglycine hydroperiodide tablet in a liter of water releases 8 mg of iodine in comparison to the 10 mg/liter released from the iodinated resin pumps described by Khan et al. Although the instructions for using iodine tincture are imprecise, the normal recommendation is 5 drops per liter of water, increasing this to 12 drops where Giardia cysts may be present. The lower of the two doses would yield about 2 mg/liter of free iodine per liter depending on the pipette used, although, because of the potassium iodide present in the formulation, a total of 4 mg iodine would be available for absorption. PMID:10689241

  4. Stability of added iodine in processed cereal foods.

    PubMed

    Thomson, B M

    2009-01-01

    The stability of iodine from iodized salt was measured in white bread, grain bread, sweet biscuits and the breakfast cereals, Weetbix (a flaked, pressed, wheat product), Ricies (a puffed rice product) and toasted muesli, as part of the New Zealand Government's initiatives to address the public health issue of low iodine intake by most New Zealanders. Triplicate runs of each product were manufactured by commercial food manufacturers between September 2006 and May 2007 with iodized and non-iodized salt. Triplicate samples were taken at various steps during processing of each food and analysed for moisture and iodine content. Iodine concentration was determined by inductively coupled plasma-mass spectrometry following an alkaline digestion. Iodine, at the equivalent of 25-65 mg of iodine per kg salt, was 100% retained in each of the selected foods from the time of mixing to the final product. These results imply that all iodine added via salt at the time of manufacture is available for consumption but not necessarily bioavailable. These data can be used for modelling the impact of strategies to increase iodine exposure. Salt as an ingredient is not a good predictor of iodine intake due to the inhomogeneity of iodine in iodized salt. PMID:19680867

  5. Relationship between Virucidal Efficacy and Free Iodine Concentration of Povidone-Iodine in Buffer Solution.

    PubMed

    Wada, Hideki; Nojima, Yasuhiro; Ogawa, Satoko; Hayashi, Nobuyuki; Sugiyama, Noriyoshi; Kajiura, Takumi; Ueda, Tomofumi; Morimoto, Shota; Yokota, Katuhiro

    2016-01-01

    Povidone-iodine solutions prepared to various concentrations (0.01, 0.1, 1 and 10%) with 0.2M phosphate buffer (pH 7.0) (PVP-I PB) were analyzed to determine their free iodine concentrations using membrane permeation cells, and their inactivation effects on three viruses (influenza A virus, poliovirus type 1 and adenovirus type 3) were examined. The free iodine concentrations in the 0.01-10% PVP-I PB were determined to be 1.84, 4.88, 1.58 and 0.17 ppm (approximate values), respectively, with the maximum obtained for the 0.1% solution. The virucidal efficacy of these PVP-I PB against poliovirus type 1 and adenovirus type 3 was found to be generally dependent on free iodine concentration, with the 0.1% solution being the most effective. Influenza A virus was inactivated with an action time of 15 s at all four concentrations examined. The results of this study suggested an association between free iodine concentration and virucidal efficacy for the 0.01-10% PVP-I PB. PMID:27009506

  6. Models of iodine behavior in reactor containments

    SciTech Connect

    Weber, C.F.; Beahm, E.C.; Kress, T.S.

    1992-10-01

    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.

  7. An Iodine Fluorescence Quenching Clock Reaction

    NASA Astrophysics Data System (ADS)

    Weinberg, Richard B.

    2007-05-01

    A fluorescent clock reaction is described that is based on the principles of the Landolt iodine reaction but uses the potent fluorescence quenching properties of triiodide to abruptly extinguish the ultraviolet fluorescence of optical brighteners present in liquid laundry detergents. The reaction uses easily obtained household products. One variation illustrates the sequential steps and mechanisms of the reaction; other variations maximize the dramatic impact of the demonstration; and a variation that uses liquid detergent in the Briggs Rauscher reaction yields a striking oscillating luminescence. The iodine fluorescence quenching clock reaction can be used in the classroom to explore not only the principles of redox chemistry and reaction kinetics, but also the photophysics of fluorescent pH probes and optical quenching.

  8. Iodine-125 radiation of posterior uveal melanoma

    SciTech Connect

    Packer, S.

    1987-12-01

    Twenty-eight cases of posterior choroidal melanoma were treated with iodine-125 in gold eye plaques. Eleven cases were located within 3.0 mm of the optic nerve (group A), nine were within 3.0 mm of the fovea (group B), and eight were within 3.0 mm of the optic nerve and fovea (group C). The mean follow-up of group A was 46.3 months; group B, 25.5 months; and group C, 42.7 months. Complications included macular edema, cataract and tumor growth. Visual acuity remained within two lines of that tested preoperatively for 4 of 11 patients in group A, 4 of 9 in group B, and 5 of 8 in group C. These results with iodine-125 suggest it as an appropriate treatment for patients with choroidal melanoma located near optic nerve and/or macula.

  9. Therapeutic implications of iodine-125 cytotoxicity

    SciTech Connect

    Bloomer, W.D.; McLaughlin, W.H.; Adelstein, S.J.

    1982-11-01

    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.

  10. Therapeutic implications of iodine-125 cytotoxicity

    SciTech Connect

    Bloomer, W.D.; McLaughlin, W.H.; Adelstein, S.J.

    1982-11-01

    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.

  11. Iodine-catalyzed etherification of morroniside.

    PubMed

    Sunghwa, Fortunatus; Sakurai, Hiroaki; Saiki, Ikuo; Koketsu, Mamoru

    2009-01-01

    In this study, we describe a highly selective etherification procedure of unprotected morroniside catalyzed by molecular iodine in acetone. The etherification reaction furnished 7-O-alkyl ether derivatives in reasonable yields within few hours under neutral conditions. Studies of the obtained products on cytotoxicity activity in colon 26-L5 cell line were examined. Among the tested compounds, 7-O-dodecylmorroniside showed moderate cytotoxic activity, having IC50 values equal to 20.9 microM. PMID:19122330

  12. 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)

    Armytage, Rosalind M. G.; Jephcoat, Andrew P.; Bouhifd, M. A.; Porcelli, Donald

    2013-07-01

    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=1.250.65 (2 s.d.) (Fe metal system) and Dmet/sil=4.331.41 (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.

  13. Inhibitory effect of low-dose inorganic iodine on thyroidal radioactive iodine uptake in healthy Japanese adults.

    PubMed

    Kunii, Yo; Uruno, Takashi; Mukasa, Koji; Sekiya, Kenichi; Iwaku, Kenji; Suzuki, Akifumi; Sugino, Kiminori; Yoshimura Noh, Jaeduk; Ito, Koichi

    2016-01-31

    In the event of a nuclear power plant accident, prophylactic administration of potassium iodide (KI) is recommended to prevent thyroid damage due to uptake of radioiodine. To assess the inhibitory effect of low-dose inorganic iodine on thyroidal radioactive iodine uptake (RAIU) in healthy adults without dietary iodine restriction, single or repeated doses of 10 mg inorganic iodine solution were given to 22 Japanese volunteers, 18 men and 4 women with the mean age of 35.7 years, between 2011 and 2013. Changes in urinary iodine excretion, thyroid function and 24-hour RAIU were also evaluated. The median 24-hour RAIU without iodine restriction was 13 % (range, 5-26 %). A single-dose of 10 mg inorganic iodine suppressed the median 24-hour RAIU measured one hour after iodine administration to 3 % (range, 1-7 %) and, in 90.9% of 22 participants their 24-hour RAIU was < 5 %. For seven participants given 10 mg of inorganic iodine daily for 14 days, the median 24-hour RAIU measured at 24 hours after the last administration of iodine was 6 % (range, 2-12 %), although the inhibitory effect was diminished in two participants. Serum thyroid stimulating hormone concentration was slightly elevated in three participants without decreased serum FT3 and FT4 levels. We conclude that a single-dose of 10 mg inorganic iodine is sufficient to inhibit RAIU in adults, although the inhibitory effect of repeated-dose on RAIU is diminished when KI is given once daily. The dose, duration or interval of iodine administration should be evaluated in iodine-sufficient regions in a future. PMID:26560237

  14. Iodine source apportionment in the Malawian diet.

    PubMed

    Watts, M J; Joy, E J M; Young, S D; Broadley, M R; Chilimba, A D C; Gibson, R S; Siyame, E W P; Kalimbira, A A; Chilima, B; Ander, E L

    2015-01-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg(-1) in maize grain, 0.008 mg kg(-1) in roots and tubers, but 0.155 mg kg(-1) in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg(-1). Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 ?g d(-1) compared to an adult requirement of 150 ?g d(-1). Despite low dietary-I intake from food, median UICs were 203 ?g L(-1) with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 ?g d(-1) based on consumption of 2?L d(-1). PMID:26503697

  15. Iodine source apportionment in the Malawian diet

    PubMed Central

    Watts, M. J.; Joy, E. J. M.; Young, S. D.; Broadley, M. R.; Chilimba, A. D. C.; Gibson, R. S.; Siyame, E. W. P.; Kalimbira, A. A.; Chilima, B.; Ander, E. L.

    2015-01-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg−1 in maize grain, 0.008 mg kg−1 in roots and tubers, but 0.155 mg kg−1 in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg−1. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d−1 compared to an adult requirement of 150 μg d−1. Despite low dietary-I intake from food, median UICs were 203 μg L−1 with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d−1 based on consumption of 2 L d−1. PMID:26503697

  16. Iodine source apportionment in the Malawian diet

    NASA Astrophysics Data System (ADS)

    Watts, M. J.; Joy, E. J. M.; Young, S. D.; Broadley, M. R.; Chilimba, A. D. C.; Gibson, R. S.; Siyame, E. W. P.; Kalimbira, A. A.; Chilima, B.; Ander, E. L.

    2015-10-01

    The aim of this study was to characterise nutritional-I status in Malawi. Dietary-I intakes were assessed using new datasets of crop, fish, salt and water-I concentrations, while I status was assessed for 60 women living on each of calcareous and non-calcareous soils as defined by urinary iodine concentration (UIC). Iodine concentration in staple foods was low, with median concentrations of 0.01 mg kg‑1 in maize grain, 0.008 mg kg‑1 in roots and tubers, but 0.155 mg kg‑1 in leafy vegetables. Freshwater fish is a good source of dietary-I with a median concentration of 0.51 mg kg‑1. Mean Malawian dietary-Iodine intake from food, excluding salt, was just 7.8 μg d‑1 compared to an adult requirement of 150 μg d‑1. Despite low dietary-I intake from food, median UICs were 203 μg L‑1 with only 12% defined as I deficient whilst 21% exhibited excessive I intake. Iodised salt is likely to be the main source of dietary I intake in Malawi; thus, I nutrition mainly depends on the usage and concentration of I in iodised salt. Drinking water could be a significant source of I in some areas, providing up to 108 μg d‑1 based on consumption of 2 L d‑1.

  17. Iodine deficiency disorders (IDD) control in India

    PubMed Central

    Pandav, Chandrakant S.; Yadav, Kapil; Srivastava, Rahul; Pandav, Rijuta; Karmarkar, M.G.

    2013-01-01

    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

  18. Radioactive iodine therapy in cats with hyperthyroidism

    SciTech Connect

    Turrel, J.M.; Feldman, E.C.; Hays, M.; Hornof, W.J.

    1984-03-01

    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.

  19. Photochemistry of halogen pyrimidines: iodine release studies.

    PubMed

    Rahn, R O

    1992-07-01

    The feasibility of using direct iodide (I-) measurements to monitor the photochemistry of the halogenated pyrimidines 5-iodocytosine and 5-iodouracil and their corresponding deoxynucleosides was examined. Radiation from either a germicidal lamp (lambda = 254 nm) or a sunlamp (lambda greater than 290 nm) was employed to induce homolytic splitting of the carbon-iodine bond and the release of iodine atoms. These atoms combine to form I2 which reacts with water to ultimately form I- and iodate (IO3-). The formation of I- was followed using either high performance liquid chromatography with electrochemical detection or a specific ion electrode. IO3- was assayed spectroscopically following its conversion to triiodide. The yields of I- relative to starting material destroyed were either close to the theoretical limit of 83% or higher depending upon (a) the compound being irradiated, (b) the irradiation wavelength and (c) the extent of exposure. Yields of iodide greater than 83% are generally accounted for by a concomitant reduction in the yield of iodate such that the sum I(-) + IO3- is approx. 100%. Because iodate is photochemically reduced to iodide by 254 nm but not sunlamp irradiation, exhaustive irradiation at 254 nm converts all of the iodate present to iodide. These studies have application to the use of photochemical methods for quantitating the percent substitution of iodinated pyrimidines in DNA, and should be useful in following the photochemistry of IdUrd and IdCyd substituted DNA. PMID:1508985

  20. Wind-bias correction method for narrowband sodium Doppler lidars using iodine absorption spectroscopy.

    PubMed

    Yuan, Tao; Yue, Jia; She, Chiao-Yao; Sherman, James P; White, Michael A; Harrell, Sean D; Acott, Phillip E; Krueger, David A

    2009-07-10

    We present a technique to measure the frequency chirp introduced by the laser pulse amplification process in the transmitter of the Colorado State University sodium lidar system. This chirp causes a systematic radial wind bias that must be removed from the reported wind measurements. An iodine absorption line located near the lidar operating wavelength of 589.16 nm is used for real-time monitoring and measurement of the chirp for the correction of radial wind bias. This technique has been thoroughly characterized in the laboratory and validated by field testing, facilitating simultaneous measurements of temperature and horizontal wind in the mesopause region of the atmosphere (80-105 km). PMID:19593351

  1. Advances in Synthetic Applications of Hypervalent Iodine Compounds.

    PubMed

    Yoshimura, Akira; Zhdankin, Viktor V

    2016-03-01

    The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C-C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of using hypervalent iodine compounds as an environmentally sustainable alternative to heavy metals. PMID:26861673

  2. Treating amiodarone-induced thyrotoxicosis with radioactive iodine.

    PubMed

    Iskandar, Said B; Jordan, Richard M; Richard, M Jordan; Peiris, Alan N

    2004-09-01

    Amiodarone use in the United States is increasing including a role in advanced cardiac life support protocols. There has been a significant increase in hypothyroidism, destructive thyroiditis (type II), and iodine-induced thyrotoxicosis (type I) with amiodarone. Preexisting thyroid disease and status of iodine intake can determine the nature of iodine-induced thyroid disease. Treating amiodarone-induced thyrotoxicosis (AIT) may include traditional antithyroid agents, glucocorticoids, and surgery. Usually, it is assumed the radioactive iodine uptake (RAIU) will be low, and this choice as a treatment modality is excluded at the initial visit. We report a satisfactory outcome in a patient with AIT using radioactive iodine. The role of radioactive iodine in treating AIT is reviewed PMID:15497570

  3. Air Density Measurements in a Mach 10 Wake Using Iodine Cordes Bands

    NASA Technical Reports Server (NTRS)

    Balla, Robert J.; Everhart, Joel L.

    2012-01-01

    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.

  4. An experimental research on the mixing process of supersonic oxygen-iodine parallel streams

    NASA Astrophysics Data System (ADS)

    Wang, Zengqiang; Sang, Fengting; Zhang, Yuelong; Hui, Xiaokang; Xu, Mingxiu; Zhang, Peng; Zhao, Weili; Fang, Benjie; Duo, Liping; Jin, Yuqi

    2014-12-01

    The O2(1Δ)/I2 mixing process is one of the most important steps in chemical oxygen-iodine laser (COIL). Based on the chemical fluorescence method (CFM), a diagnostic system was set up to image electronically excited fluorescent I2(B3П0) by means of a high speed camera. An optimized data analysis approach was proposed to analyze the mixing process of supersonic oxygen-iodine parallel streams, employing a set of qualitative and quantitative parameters and a proper percentage boundary threshold of the fluorescence zone. A slit nozzle bank with supersonic parallel streams and a trip tab set for enhancing the mixing process were designed and fabricated. With the diagnostic system and the data analysis approach, the performance of the trip tab set was examined and is demonstrated in this work. With the mixing enhancement, the fluorescence zone area was enlarged 3.75 times. We have studied the mixing process under different flow conditions and demonstrated the mixing properties with different iodine buffer gases, including N2, Ar, He and CO2. It was found that, among the four tested gases, Ar had the best penetration ability, whilst He showed the best free diffusion ability, and both of them could be well used as the buffer gas in our experiments. These experimental results can be useful for designing and optimizing COIL systems.

  5. Xenon and iodine reveal multiple distinct exotic xenon components in Efremovka "nanodiamonds"

    NASA Astrophysics Data System (ADS)

    Gilmour, J. D.; Holland, G.; Verchovsky, A. B.; Fisenko, A. V.; Crowther, S. A.; Turner, G.

    2016-03-01

    We identify new xenon components in a nanodiamond-rich residue from the reduced CV3 chondrite Efremovka. We demonstrate for the first time that these, and the previously identified xenon components Xe-P3 and Xe-P6, are associated with elevated I/Xe ratios. The 129I/127I ratio associated with xenon loss from these presolar compositions during processing on planetesimals in the early solar system was (0.369 ± 0.019) × 10-4, a factor of 3-4 lower than the canonical value. This suggests either incorporation of iodine into carbonaceous grains before the last input of freshly synthesized 129I to the solar system's precursor material, or loss of noble gases during processing of planetesimals around 30 Myr after solar system formation. The xenon/iodine ratios and model closure ages were revealed by laser step pyrolysis analysis of a neutron-irradiated, coarse-grained nanodiamond separate. Three distinct low temperature compositions are identified by characteristic I/Xe ratios and 136Xe/132Xe ratios. There is some evidence of multiple compositions with distinct I/Xe ratios in the higher temperature releases associated with Xe-P6. The presence of iodine alongside Q-Xe and these components in nanodiamonds constrains the pathway by which extreme volatiles entered the solid phase and may facilitate the identification of their carriers. There is no detectable iodine contribution to the presolar Xe-HL component, which is released at intermediate temperatures; this suggests a distinct trapping process. Releases associated with the other components all include significant contributions of 128Xe produced from iodine by neutron capture during reactor irradiation. We propose a revised model relating the origin of Xe-P3 (which exhibits an s-process deficit) through a "Q-process" to the Q component (which makes the dominant contribution to the heavy noble gas budget of primitive material). The Q-process incorporates noble gases and iodine into specific carbonaceous phases with mass dependent fractionation relative to the ambient composition. Q-Xe is dominated by the products of this "Q-process" occurring shortly before or during solar system formation. Carriers that trapped xenon by earlier Q-process events were altered, perhaps by supernova shocks, converting some Q carriers into P3 carriers. Unlike Q carriers, these carriers preserve the isotopic signature of the xenon they trapped through oxidation of samples in the laboratory. P3 carriers thus disproportionately sample xenon that was incorporated before galactic chemical evolution had produced the solar xenon signature by enriching ambient xenon with s-process material.

  6. Electrolytic trapping of iodine from process gas streams

    DOEpatents

    Horner, Donald E.; Mailen, James C.; Posey, Franz A.

    1977-01-25

    A method for removing molecular, inorganic, and organic forms of iodine from process gas streams comprises the electrolytic oxidation of iodine in the presence of cobalt-III ions. The gas stream is passed through the anode compartment of a partitioned electrolytic cell having a nitric acid anolyte containing a catalytic amount of cobalt to cause the oxidation of effluent iodine species to aqueous soluble species.

  7. [Iodine deficiency in pregnancy--a continuing public health problem].

    PubMed

    Szybi?ski, Zbigniew

    2005-01-01

    Iodine prophylaxis in Poland started in 1997 and is based on mandatory iodzation of household salt with 20-40 mg KI/ 1 kg, supplementation of bottle fed infants with iodized formulas with 10,0 microg KI/100 ml, and a voluntary supplementation of pregnant and breast feeding women with additional 100-150 microg of iodine/ day. Last evaluation of efficacy of the iodine prophylaxis performed in 2003 by WHO and International Council for the Control of Iodine Deficiency Disorders allocated Poland within the group of the European countries with sufficient iodine supplementation on the population level. However according to data of the Institute of Mather and Chield in Poland, around 50 % of pregnant women only is additionally supplemented with iodine. Iodine deficiency during pregnancy even as a moderate iodine deficiency, creates a risk of mental retardation, perinatal complication like low and very low births weigt of neonates with increased perinatal mortality rate and late consequences in adult life: metabolic syndrom and type 2 diabetes. Another limitation of the actual model of iodine prophylaxis in Poland, it is too high consumption of natrum chloride (over 5,0 g of household salt/day/ capita). It is around 50% over WHO recommendation. Intensive preventive program against hypertension, type 2 diabetes, atherosclerosis, osteoporosis and some neoplasmatic diseases includes limitation of natrum chloride consumption- as one of the risk factors. Therefore new scope of the National Programme for Elimination of Iodine Deficiency will include: a special prorgramme for the iodization of animal food according to european standard, increased rate of pregnant women additionally supplemented with iodine, strengthening public awarness on necessary increase of milk consumption especially in pregnancy and in children and continouse monitoring system of biologic effects and technologic quality of the model of iodine prophylaxis. PMID:16335675

  8. Engineering planetary lasers for interstellar communication. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Sherwood, Brent

    1988-01-01

    Transmitting large amounts of data efficiently among neighboring stars will vitally support any eventual contact with extrasolar intelligence, whether alien or human. Laser carriers are particularly suitable for high-quality, targeted links. Space laser transmitter systems designed by this work, based on both demonstrated and imminent advanced space technology, could achieve reliable data transfer rates as high as 1 kb/s to matched receivers as far away as 25 pc, a distance including over 700 approximately solar-type stars. The centerpiece of this demonstration study is a fleet of automated spacecraft incorporating adaptive neural-net optical processing active structures, nuclear electric power plants, annular momentum control devices, and ion propulsion. Together the craft sustain, condition, modulate, and direct to stellar targets an infrared laser beam extracted from the natural mesospheric, solar-pumped, stimulated CO2 emission recently discovered at Venus. For a culture already supported by mature interplanetary industry, the cost of building planetary or high-power space laser systems for interstellar communication would be marginal, making such projects relevant for the next human century. Links using high-power lasers might support data transfer rates as high as optical frequencies could ever allow. A nanotechnological society such as we might become would inevitably use 10 to the 20th power b/yr transmission to promote its own evolutionary expansion out of the galaxy.

  9. Efforts to Consolidate Chalcogels with Adsorbed Iodine

    SciTech Connect

    Riley, Brian J.; Pierce, David A.; Chun, Jaehun

    2013-08-28

    This document discusses ongoing work with non-oxide aerogels, called chalcogels, that are under development at the Pacific Northwest National Laboratory as sorbents for gaseous iodine. Work was conducted in fiscal year 2012 to demonstrate the feasibility of converting Sn2S3 chalcogel without iodine into a glass. This current document summarizes the work conducted in fiscal year 2013 to assess the consolidation potential of non-oxide aerogels with adsorbed iodine. The Sn2S3 and Sb13.5Sn5S20 chalcogels were selected for study. The first step in the process for these experiments was to load them with iodine (I2). The I2 uptake was ~68 mass% for Sn2S3 and ~50 mass% for Sb13.5Sn5S20 chalcogels. X-ray diffraction (XRD) of both sets of sorbents showed that metal-iodide complexes were formed during adsorption, i.e., SnI4 for Sn2S3 and SbI3 for Sb13.5Sn5S20. Additionally, metal-sulfide-iodide complexes were formed, i.e., SnSI for Sn2S3 and SbSI for Sb13.5Sn5S20. No XRD evidence for unreacted iodine was found in any of these samples. Once the chalcogels had reached maximum adsorption, the consolidation potential was assessed. Here, the sorbents were heated for consolidation in vacuum-sealed quartz vessels. The Sb13.5Sn5S20 chalcogel was heated both (1) in a glassy carbon crucible within a fused quartz tube and (2) in a single-containment fused quartz tube. The Sn2S3 chalcogel was only heated in a single-containment fused quartz tube. In both cases with the single-containment fused quartz experiments, the material consolidated nicely. However, in both cases, there were small fractions of metal iodides not incorporated into the final product as well as fused quartz particles within the melt due to the sample attacking the quartz wall during the heat treatment. The Sb13.5Sn5S20 did not appear to attack the glassy carbon crucible so, for future experiments, it would be ideal to apply a coating, such as pyrolytic graphite, to the inner walls of the fused quartz vessel to prevent melt attack.

  10. Iodine accumulation in sea urchin larvae is dependent on peroxide.

    PubMed

    Miller, Ashley E M; Heyland, Andreas

    2013-03-01

    Iodine has many important biological functions and its concentrations vary with the environment. Recent research has provided novel insights into iodine uptake mechanisms in marine bacteria and kelp through hydrogen peroxide-dependent diffusion (PDD). This mechanism is distinct from sodium-dependent mechanisms known from vertebrates. In vertebrates, iodine accumulates in the thyroid gland by the action of the apical iodide transporter (AIT) and the sodium/iodide symporter (NIS). Neither of these proteins has, thus far, been identified outside of the chordates, and PDD (as an iodine uptake mechanism) has never been studied in animals. Using (125)I as a marker for total iodine influx, we tested iodine uptake via sodium-dependent transport versus PDD in embryos and larvae of the sea urchin Strongylocentrotus purpuratus. We found that iodine uptake in S. purpuratus is largely independent of NIS/AIT. Instead, we found that uptake is dependent on the presence and production of hydrogen peroxide, indicating that sea urchin larvae use PDD as a mechanism for iodine acquisition. Our data, for the first time, provide conclusive evidence for this mechanism in an animal. Furthermore, our data provide preliminary evidence that sodium-dependent iodine uptake via active transporter proteins is a synapomorphy of vertebrates. PMID:23155081

  11. Recent experiences with iodine water disinfection in Shuttle

    NASA Technical Reports Server (NTRS)

    Gibbons, Randall E.; Flanagan, David T.; Schultz, John R.; Sauer, Richard L.; Slezak, Terry N.

    1990-01-01

    Microbial proliferation in the STS potable water system is prevented by maintaining a 2-5 ppm iodine residual. The iodine is added to fuel cell water by an iodinated ion exchange resin in the Microbial Check Valve (MCV). Crew comments indicated excessive iodine in the potable water. To better define the problem, a method of in-flight iodine analysis was developed. Inflight analysis during STS-30 and STS-28 indicated iodine residuals were generally in the 9-13 ppm range. It was determined that the high iodine residual was caused by MCV influent temperatures in excess of 120 F. This is well above the MCV operating range of 65-90 F. The solution to this problem was to develop a resin suitable for the higher temperatures. Since 8 months were required to formulate a MCV resin suitable for the higher temperatures, a temporary solution was necessary. Two additional MCV's were installed on the chilled and ambient water lines leading into the galley to remove the excess iodine. These reduced the iodine residual to 3-4 ppm during STS-33, STS-34, STS-36 and STS-32. A high-temperature resin was formulated and initially flown on STS-31.

  12. Mission and System Advantages of Iodine Hall Thrusters

    NASA Technical Reports Server (NTRS)

    Dankanich, John W.; Szabo, James; Pote, Bruce; Oleson, Steve; Kamhawi, Hani

    2014-01-01

    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.

  13. Medical effects of iodine disinfection products in spacecraft water

    NASA Technical Reports Server (NTRS)

    Sauer, Richard L.; Janik, Daniel S.; Thorstenson, Yvonne R.

    1987-01-01

    Various iodination products (IDPs), including iodinated and iodine-induced new compounds, will be present in the iodine-disinfected water that is expected to be used by crews on the NASA Space Station and on long duration missions. The metabolic intermediaries created by such a process may be more important to crew health than the parent IDPs, and reclamation and recycling may be expected to produce additional products. These medical effects may be expressed in crews as hypersensitivity, allergic, acute toxic, and chronic toxic reactions, as well as modifications of immune system response.

  14. Selenium deficiency mitigates hypothyroxinemia in iodine-deficient subjects.

    PubMed

    Vanderpas, J B; Contempr, B; Duale, N L; Deckx, H; Bebe, N; Longomb, A O; Thilly, C H; Diplock, A T; Dumont, J E

    1993-02-01

    Studies were performed to assess the role of combined selenium and iodine deficiency in the etiology of endemic myxedematous cretinism in a population in Zaire. One effect of selenium deficiency may be to lower glutathione peroxidase activity in the thyroid gland, thus allowing hydrogen peroxide produced during thyroid hormone synthesis to be cytotoxic. In selenium-and-iodine-deficient humans, selenium supplementation may aggravate hypothyroidism by stimulating thyroxin metabolism by the selenoenzyme type I iodothyronine 5'-deiodinase. Selenium supplementation is thus not indicated without iodine or thyroid hormone supplementation in cases of combined selenium and iodine deficiencies. PMID:8427203

  15. Study of molecular iodine, iodate ions, iodide ions, and triiodide ions solutions absorption in the UV and visible light spectral bands

    NASA Astrophysics Data System (ADS)

    Kireev, S. V.; Shnyrev, S. L.

    2015-07-01

    The paper reports on experimental studies concerning the absorption spectra of molecular iodine and its \\text{IO}3- , I-, \\text{I}3- anions in the spectral band of 180-600?nm. Values of the absorption cross-sections of the above mentioned substances have been measured, and relations of absorption coefficients to concentrations have been studied. The results obtained demonstrate that the spectral band under consideration is likely to be successfully used for simultaneous real-time detection of substances containing iodine with an absorption method using laser emission sources in the UV and visible light spectral bands.

  16. Method for the simultaneous preparation of Radon-211, Xenon-125, Xenon-123, Astatine-211, Iodine-125 and Iodine-123

    DOEpatents

    Mirzadeh, Saed; Lambrecht, Richard M.

    1987-01-01

    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.

  17. Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey.

    PubMed

    Vandevijvere, Stefanie; Amsalkhir, Sihame; Mourri, Ahmed Bensouda; Van Oyen, Herman; Moreno-Reyes, Rodrigo

    2013-06-28

    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

  18. Method for gettering organic, inorganic and elemental iodine in aqueous solutions

    DOEpatents

    Beahm, Edward C.; Shockley, William E.

    1990-01-01

    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.

  19. Development of safe infrared gas lasers

    NASA Astrophysics Data System (ADS)

    Mainuddin; Singhal, Gaurav; Tyagi, R. K.; Maini, A. K.

    2013-04-01

    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.

  20. Kinetics of iodine monofluoride excitation by energetic nitrogen

    NASA Astrophysics Data System (ADS)

    Piper, L. G.; Marinelli, W. J.; Green, B. D.; Rawlins, W. T.; Murphy, H. C.

    1985-10-01

    We studied the production and loss of IF (Iodine MonoFluoride) in our flow system using a laser-induced fluorescence diagnostic for measuring IF number densities. We related the production of F-atoms to the residence time of CF4 in the microwave discharge and found a yield of about 0.3 F-atoms per CF4 molecule under typical operating conditions. We identified flow conditions that produce complete reaction of CF3I in the injector and showed that a negligible amount of IF is destroyed in the injector under these conditions. Some loss of IF in the main flow tube was found at low flow velocities; however, this loss appeared to be negligible at higher velocities and permitted us to operate in a regime where IF number densities were directly related to the amount of CF3I flowing into the injector. We also found that operation of the injector using excess CF3I resulted in the deposition of an optically opaque thin film on the reactor walls. This required us to operate in excess F-atoms and eliminated the need to measure absolute F-atom number densities.

  1. Iodine Affects Differentiation and Migration Process in Trophoblastic Cells.

    PubMed

    Olivo-Vidal, Zendy Evelyn; Rodrguez, Roci Coutio; Arroyo-Helguera, Omar

    2016-02-01

    Iodine deficiency is associated with oxidative stress increase and preeclampsia during gestation, suggesting that iodine concentration plays an important role in the normal placenta physiology. The question raised is to analyze the effect of iodine deficiency on oxidative stress, viability, differentiation, and migration process and changes in the expression of differentiation and migration markers. Iodine deprivation was done using potassium perchlorate (KCLO4) to block sodium iodide symporter (NIS) transporter and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid DIDS to inhibit pendrine (PEN) transport for 3-48h. Then trophoblast cells were treated with low iodine doses of 5-500?M and high iodine doses of 100-5000?M. Oxidative stress, viability, and human chorionic gonadotropin (hGC) were measured by colorimetric methods. Migration throphoblast cells were evaluated by both wound healing and Boyden chamber assays. Changes in mRNA expression were analyzed by real-time RT-PCR. Iodine deprivation induces a significant increase of reactive oxygen species (ROS), viability, and migration process vs control cells. We found a significant overregulation in the mRNA's peroxisome proliferator-activated receptor (PPAR-gamma), Snail, and matrix metalloproteinase-9 (MMP-9) mRNA's in cells deprived of iodine, as well as a down glial cell missing-1 (GCM-1) regulation, hGC, pregnancy-associated plasma protein-A (PAPP-A), and E-cadherin mRNA expression. The expression of hypoxic induction factor alpha (HIF?) mRNA does not change with iodine deprivation. In cells deprived of iodine, supplementinglow iodine doses (5-500?M) does not induce any significant changes in viability. However, ROS and migration process were decreased, although we found an increased human chorionic gonadotropin (hCG) secretion as a differentiation marker. In addition, we found that PPAR-gamma, Snail, and MPP-9 mRNAs expression are downregulated with low iodine doses, in contrast with GCM-1, PAPP-A, hGC, and E-cadherin that increase their expression vs cells deprived of iodine. High iodine doses (1000-5000?M) have shown cytotoxic effects. Based on our results, iodine is important for keeping the proliferation/differentiation balance in the placenta. PMID:26152853

  2. Interdisciplinary aspects of iodine prophylaxis in German Democratic Republic.

    PubMed

    Bauch, K; Anke, M; Gürtler, H; Hesse, V; Knappe, G; Körber, R; von Kozierowski, F; Meng, W; Thomas, G; Ulrich, F E

    1989-06-01

    Endemic goiter still occurs in several European countries. Alimentary iodine deficiency could be proved as the main cause of endemic prevalence. Extensive epidemiologic surveys showed the great medical and economical impact of this matter for the GDR. Over 200 million Marks might be spent for diagnosis and treatment of thyroid patients per year. Also in the field of veterinary medicine and animal production iodine deficiency plays an important role. Under the conditions of iodine deficiency the fodder containing nitrate and glucosinolates (e.g. bruised rape extraction) results in additional goitrogenic effects (so-called indirect or relative iodine deficiency). Due to iodine deficiency disorders considerable losses of yields in cattle, pigs and sheep occurred. The content of iodine in animal products used for human nutrition was subsequently low. Considering the ecological implication of these problems an Interdisciplinary Iodine Commission within the Society for Endocrinology and Diseases of Metabolism of the GDR was established. Together with the governement authorities it worked out corresponding recommendations for the prophylaxis and control of its efficiency. In 1986 the iodination of most of the packed salt (32 mg KIO3/kg = = 19 mg I/kg) and the administration of iodinated mineral mixtures for the animal production were started for pigs in the whole territory of GDR and for cattle in the southern counties of the GDR only. These activities have been accompanied by information of TV as well as in the newspapers and medical journals. Thus, an improved supply of iodine to the population through iodinated table salt and animal products can be taken into account. The efficiency of these prophylactic measures is controlled interdisciplinarily.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2776697

  3. Global 3-D model studies of tropospheric iodine

    NASA Astrophysics Data System (ADS)

    Mantle, Hannah; Chipperfield, Martyn; Hossaini, Ryan; Feng, Wuhu; Plane, John; Breider, Tom; Mann, Graham

    2014-05-01

    Halogen species play an important role in tropospheric chemistry. Iodine is believed to enhance catalytic ozone loss (acting synergistically with bromine) and can lead to the formation of new particles. Recent observations have increased our knowledge on the role of iodine but key processes need to be tested and quantified by inclusion in numerical models. We describe the development of an iodine chemistry scheme within the TOMCAT global 3-D chemical transport model (CTM). The existing model contained a detailed tropospheric chemistry scheme (including bromine) along with the GLOMAP aerosol scheme. The new iodine scheme contains a treatment of organic source gas emissions along with a new parameterisation of HOI and I2 emission from the ocean based on recent laboratory work. The model has been integrated at a horizontal resolution of 2.8o x 2.8o and is forced by ECMWF analyses for annual integrations. We have used the model, coupled to a detailed size-resolved aerosol microphysics module, to study iodine chemistry in the troposphere. We will present comparisons with a range of surface, ship-borne, aircraft and satellite observations. The model reproduces observed surface CH3I distributions. Mixing ratios of other organic iodine compounds are small due to shorter lifetimes. Our simulations show the observed IO at Cape Verde in the Tropical East Atlantic cannot be reproduced with the measured organic iodine source fluxes alone and requires an additional iodine source, in agreement with other studies. Inclusion of the inorganic source improves the agreement, but the model still underestimates the largest observed OI, with HOI being the most abundant Iy species. Our simulations show iodine chemistry significantly perturbs tropospheric ozone. Emissions of organic iodine species result in a 17 Tg reduction in the troposphere ozone burden. The dominant iodine-driven ozone sink is the reaction of HO2 + IO (175 Tg O3 yr-1).

  4. Iodine Sorbent Performance in FY 2012 Deep Bed Tests

    SciTech Connect

    Nick Soelberg; Tony Watson

    2012-08-01

    Nuclear fission results in the production of fission products and activation products, some of which tend to be volatile during used fuel reprocessing and evolve in gaseous species into the reprocessing facility off-gas systems. Analyses have shown that I-129, due to its radioactivity, high potential mobility in the environment, and high longevity (half life of 15.7 million years), can require control efficiencies of up to 1,000x or higher to meet regulatory emission limits. Iodine capture is an important aspect of the Separations and Waste Forms Campaign Off-gas Sigma Team (Jubin 2011, Pantano 2011). Deep-bed iodine sorption tests for both silver-functionalized Aerogel and silver zeolite sorbents were performed during Fiscal Year 2012. These tests showed that: • Decontamination factors were achieved that exceed reasonably conservative estimates for DFs needed for used fuel reprocessing facilities in the U.S. to meet regulatory requirements for I-129 capture. • Silver utilizations approached or exceeded 100% for high inlet gas iodine concentrations, but test durations were not long enough to approach 100% silver utilization for lower iodine concentrations. • The depth of the mass transfer zone was determined for both low iodine concentrations (under 10 ppmv) and for higher iodine concentrations (between 10-50 ppmv); the depth increases over time as iodine is sorbed. • These sorbents capture iodine by chemisorption, where the sorbed iodine reacts with the silver to form very non-volatile AgI. Any sorbed iodine that is physisorbed but not chemically reacted with silver to form AgI might not be tightly held by the sorbent. The portion of sorbed iodine that tends to desorb because it is not chemisorbed (reacted to form AgI) is small, under 1%, for the AgZ tests, and even smaller, under 0.01%, for the silver-functionalized Aerogel.

  5. Intermolecular Cyclopropanation of Styrenes Using Iodine and Visible Light via Carbon-Iodine Bond Cleavage.

    PubMed

    Usami, Kaoru; Nagasawa, Yoshitomo; Yamaguchi, Eiji; Tada, Norihiro; Itoh, Akichika

    2016-01-01

    The intermolecular cyclopropanation of aromatic olefins with activated methylene compounds using iodine and visible light irradiation was described. This reaction proceeds under rare-metal-free conditions. Styrenes with various substituted groups (alkyl and electron-withdrawing groups) provided corresponding cyclopropanes in moderate to good yields. PMID:26654114

  6. Iodine deficiency, other trace elements, and goitrogenic factors in the etiopathogeny of iodine deficiency disorders (IDD).

    PubMed

    Thilly, C H; Vanderpas, J B; Bebe, N; Ntambue, K; Contempre, B; Swennen, B; Moreno-Reyes, R; Bourdoux, P; Delange, F

    1992-01-01

    Severe goiter, cretinism, and the other iodine deficiency disorders (IDD) have their main cause in the lack of availability of iodine from the soil linked to a severe limitation of food exchanges. Apart from the degrees of severity of the iodine deficiency, the frequencies and symptomatologies of cretinism and the other IDD are influenced by other goitrogenic factors and trace elements. Thiocyanate overload originating from consumption of poorly detoxified cassava is such that this goitrogenic factor aggravates a relative or a severe iodine deficiency. Very recently, a severe selenium deficiency has also been associated with IDD in the human population, whereas in animals, it has been proven to play a role in thyroid function either through a thyroidal or extrathyroidal mechanism. The former involves oxidative damages mediated by free radicals, whereas the latter implies an inhibition of the deiodinase responsible for the utilization of T4 into T3. One concludes that: 1. Goiter has a multifactorial origin; 2. IDD are an important public health problem; and 3. IDD are a good model to study the effects of other trace elements whose actions in many human metabolisms have been somewhat underestimated. PMID:1375059

  7. Absolute frequency measurement for the emission transitions of molecular iodine in the 982 - 985 nm range

    SciTech Connect

    Matyugin, Yu A; Ignatovich, S M; Kuznetsov, Sergei A; Nesterenko, M I; Okhapkin, M V; Pivtsov, V S; Skvortsov, Mikhail N; Bagaev, Sergei N

    2012-03-31

    We report high-precision frequency measurements of the separate hyperfine structure (HFS) components of the emission B - X system transitions of {sup 127}I{sub 2} molecules in the 982 - 985 nm range. To resolve the HFS of the emission lines, advantage was taken of the method of three-level laser spectroscopy. The function of exciting radiation was fulfilled by the second harmonic of a cw Nd : YAG laser, and the probe radiation in the 968 - 998 nm range was generated by an external-cavity diode laser. The output Nd : YAG laser frequency was locked to an HFS component of the absorption transition and the probing laser radiation to the emission transition component. When both frequencies were locked to HFS components with a common upper level, the output diode laser frequency was precisely equal to the emission transition frequency. The output frequency of the thus stabilised diode laser was measured with the help of a femtosecond optical frequency synthesiser based on a Ti : sapphire laser. We present the results of the absolute frequency measurements of 20 HFS components belonging to six vibrational - rotational transitions of the B - X system of iodine [R56(32 - 48)a1, P58(32 - 48)a1, P85(33 - 48)a1, R87(33 - 48a1, R88(33 - 48)a10] and all 15 components of the R86(33 - 48) line. The relative measurement uncertainty is equal to 7 Multiplication-Sign 10{sup -10} and is determined by the frequency instability of the diode laser radiation.

  8. Electrodeposition of a tellurium-iodine compound

    SciTech Connect

    Bigelis, V.M.

    1988-01-01

    Forming more stable tellurium in iodide solution was investigated. Solutions with a large excess of iodide ions were prepared and radiotracers measured the current yields of tellurium. A platinum sheet was used as cathode, a tellurium rod was the anode, and a saturated silver-silver chloride electrode was the reference electrode. Electrodeposition and polarization measurements were conducted by a potentiostat. Polarization curves were obtained. Iodine 125 and tellurium 123m were used in the radiochemical analysis of the deposition yield and rate. Radioactivity measurements were made with a Ge(Li) detector.

  9. Isostrychnine synthesis mediated by hypervalent iodine reagent.

    PubMed

    Jacquemot, Guillaume; Maertens, Gatan; Canesi, Sylvain

    2015-05-18

    Althought there are several reported synthetic routes to strychnine, one of the most widely recognized alkaloids, we report an unexplored route with an oxidative dearomatizing process mediated by hypervalent iodine as the key step. The new syntheses of isostrychnine and strychnine have been achieved from an readily available phenol in nine and ten steps. In addition to the key step, these syntheses involve an aza Michael-ether-enol tandem transformation, two heck type cyclizations, a reductive isomerization, and a double reductive amination in cascade leading to the alkaloid main core. PMID:25832293

  10. The addition of iodine to tetramethylammonium iodide

    USGS Publications Warehouse

    Foote, H.W.; Fleischer, M.

    1953-01-01

    The system tetramethylammonium iodide-iodine-toluene has been studied by the solubility method at 6 and at 25??. The compounds (CH3)4NI3, (CH3)4NI5 and (CH3)4NI11 were found to be stable phases at both temperatures. In addition, the compound (CH3)4NI10 was found at 6?? and the compound (CH3)4NI9 at 25??. The dissociation pressures of the compounds at these temperatures were calculated from the solubility data.

  11. Viscosity of high-temperature iodine

    NASA Technical Reports Server (NTRS)

    Kang, Steve H.; Kunc, Joseph A.

    1991-01-01

    The viscosity coefficient of iodine in the temperature range 500 - 3000 K is calculated. Because of the low dissociation energy of the I2 molecules, the dissociation degree of the gas increases quickly with temperature, and I + I2 and I + I collisions must be taken into account in calculation of viscosity at temperatures greater than 1000 deg. Several possible channels for atom-atom interaction are considered, and the resulting collision integrals are averaged over all the important channels. It is also shown that the rigid-sphere model is inaccurate in predictions of the viscosity.

  12. Effects of diuretics on iodine uptake in non-toxic goitre: comparison with low-iodine diet.

    PubMed

    Kapucu, L Ozlem; Azizoglu, Firat; Ayvaz, Goksun; Karakoc, Ayhan

    2003-09-01

    Low-iodine diet has been employed to achieve iodine depletion prior to radioiodine (RI) therapy. However, treatment with diuretics may be more effective than low-iodine diet in causing iodine depletion and subsequent increase in RI uptake by the thyroid. Fifty-five patients with non-toxic goitre were given 0.20 MBq RI p.o. on the first day of the study and thyroid uptake was measured. In 15 patients, a low-iodine diet was started and continued for 14 days. The remaining 40 patients received furosemide 40 mg/day orally for 5 days with an unrestricted diet. On the 15th day of the study, all patients were given 0.20 MBq RI p.o. and thyroid RI uptake was measured again. Additionally, 24-h urinary iodine excretion and RI clearance were measured on the 1st and 6th days in 21 patients from the furosemide group and on the 1st and 15th days in eight patients from the diet group. Furosemide administration led to a 58.40% increase in iodine uptake over the baseline value, which was significantly higher than the increase caused by low-iodine diet (17.22%) ( P<0.0001). Urinary excretion of RI decreased in both groups similarly (furosemide, 29.45%; low-iodine diet, 21.06%; P=0.33). Iodine clearance also decreased in each group similarly (10.61% vs 7.53%, P=0.53). Treatment with furosemide prior to administration of RI increases the uptake of RI by the thyroid more effectively than does low-iodine diet. PMID:12845488

  13. Determination of iodine to compliment mass spectrometric measurements

    SciTech Connect

    Hohorst, F.A.

    1994-11-01

    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.

  14. Iodine Deficiency in Australia: Be Alarmed. Opinions & Perspectives

    ERIC Educational Resources Information Center

    McElduff, Aidan; Beange, Helen

    2004-01-01

    Iodine deficiency, the leading preventable cause of intellectual impairment in the world (World Health Organization, 1999), has reappeared in Australia. Recently, we identified the re-emergence of iodine deficiency in Sydney (Gunton, Hams, Fiegert & McElduff, 1999). This has been confirmed locally (Li, Ma, Boyages & Eastman, 2001) and…

  15. Povidone iodine skin absorption: an ex-vivo study.

    PubMed

    Nesvadbova, Martina; Crosera, Matteo; Maina, Giovanni; Larese Filon, Francesca

    2015-06-15

    Povidone iodine is a water-soluble complex used to disinfect the skin surface and it exerts prolonged germicidal action against a broad spectrum of germs. Indeed, it is often applied on burned skin, large wounds, deep tissues or mucosa. Notably some surgical hand-scrub solutions, which are considered safe antiseptics, contain large amounts of iodine that can be absorbed by skin. The aim of present study was to study the skin absorption of iodine after the application on the skin of povidone-iodine solution, used by health care workers during surgical procedure. We use Franz diffusion static cells with human skin. After 24h from the beginning of our measurement the iodine concentration in the receiving compartment was 11.596.3?g/cm(2). The medium flux calculated was 0.730.33?g/cm(2)/h with a lag time of 8.91.5h. These in vitro results confirmed that povidone iodine could pass through the skin in a relevant amount that can explain the clinical findings in burned or surgically treated patients. In professional use the repetitive contact with povidone iodine, also as soap, can cause iodine skin permeation that must be considered when the washing procedures are repeated more than 20 times a day. PMID:25858112

  16. Comparison of methods for iodine analysis in foods.

    PubMed

    Judprasong, K; Jongjaithet, N; Chavasit, V

    2016-02-15

    Spectrophotometric and ICP-MS methodology for iodine determination was compared. Samples were alkali dry-ashed, dissolved in water, and iodine assayed by spectrophotometry and by ICP-MS. Iodine content in the studied foods ranged from 3 to 1304μg/100g. There was no significant difference (p>0.05) between iodine values determined spectrophotometrically using an external calibration curve and values determined using a standard addition. Foods containing low iodine concentrations (4-25μg/100g) also showed no significant difference (p>0.05) between iodine concentrations determined spectrophotometrically and concentrations determined by ICP-MS. For food items with more than 25μg/100g, the spectrophotometric methods yielded markedly higher (p<0.05) concentrations than the standard ICP-MS method (relative positive bias 25-122%), especially in foods with high sodium and/or iron contents. A catalytic effect of sodium and iron on the Sandell and Kolthoff reaction, leading to false high values in the spectrophotometric determination of iodine was demonstrated. ICP-MS is recommended for iodine determination in foods. PMID:26433281

  17. 21 CFR 520.1157 - Iodinated casein tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iodinated casein tablets. 520.1157 Section 520.1157 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS 520.1157 Iodinated...

  18. 21 CFR 520.1157 - Iodinated casein tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iodinated casein tablets. 520.1157 Section 520.1157 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS 520.1157 Iodinated...

  19. 21 CFR 520.1157 - Iodinated casein tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iodinated casein tablets. 520.1157 Section 520.1157 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS 520.1157 Iodinated casein tablets. (a) Specifications. Each 1-gram...

  20. [Effects of cooking methods on iodine content in iodized salt].

    PubMed

    Shi, L; Zhou, R; Wang, G

    1998-11-30

    Effects of cooking methods and variety of foods on the retention of iodine content in food with iodized salt were studied. Vegetables from market and usual cooking methods were selected, including procedures of various cooking methods. The samples were fixed by potassium carbonate, ashed with zinc sulfate at 550 degrees C, then determined by colorimetric method with Ce-As-I catalytical reaction. The different cooking methods had different effects on the retention of iodine, in general, the retention of iodine by stewing of steaming was higher than by stir-frying. The effect of various vegetables on the retention of iodine was also different. The retention of iodine after stir-frying was 84.2%, 56.9%, 44.5%, 36.6% for fruit-bearing vegetables, leafy vegetables, roots and beans. The retention of iodine after stewing was 66.1%, 53.4%, 47.0%, and 43.2% for fruit-bearing vegetables, roots, beans and meat. The stability of organic iodine in food is higher than that of inorganic iodine. PMID:11939033