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1

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

Han, K. S.

1985-01-01

2

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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.

Han, K. S.

1986-01-01

3

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

4

Solar-pumped photodissociation iodine laser  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

5

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

Han, Kwang S.; Hwang, In Heon

1990-01-01

6

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

7

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

Han, Kwang S.

1987-01-01

8

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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.

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

1988-01-01

9

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

10

Low threshold solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

Solar-pumped lasing of i-C3F7I and n-C4F9I at lower solar concentrations (170 solar constants) and longer gain lengths than previous solar lasers is demonstrated, with potential application to the lasing needs of space. Two xenon arc solar simulators provide an AM0 spectrum over the 60-cm gain length, and output pulse energies of 70 mJ and an average power of 550 mW are achieved. Low pressure lasing times of 600 ms are reached, and the observed 0.074 percent slope efficiency could approach the 0.2 percent maximum theoretical efficiency. Due to less quenching of I(asterisk), n-C4F9I is found to be a superior lasant to i-C3F7I.

Deyoung, R. J.

1986-01-01

11

Direct solar-pumped iodine laser amplifier  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

12

Amplified spontaneous emission in solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

13

A long-pulse amplifier for solar-pumped iodine lasers  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

14

Beam profile measurement of a solar-pumped iodine laser  

NASA Technical Reports Server (NTRS)

Beam profile measurements have been made as a function of time within the laser pulse and C2F5I pressure. Measurements indicate that the profile is determined directly by the optical excitation volume, produced by the solar simulator, and that media distortion plays a minor role compared to the build up of quenching species during the lasing pulse.

De Young, Russell J.

1986-01-01

15

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

NASA Technical Reports Server (NTRS)

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.

Shiner, Christopher S.

1986-01-01

16

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

17

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

NASA Technical Reports Server (NTRS)

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

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

1997-01-01

18

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

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

19

Direct solar pumped laser  

SciTech Connect

A direct solar pumped laser operates on emission from the phosphorescent T1 -> SO transition of a suitable dye molecule used in liquid or solid solution. The first excited singlet electronic state s1 is excited from the ground state so by light from solar concentrators absorbed in the absorption bands of the strong spin-allowed transitions sp <- so, P > or = 1, where the primary absorption band is usually P 1. Excitation of dye molecules to the first triplet state t1 occurs via intersystem crossing from s1 to the triplet state manifold.

Volkin, H.C.

1981-07-28

20

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

NASA Technical Reports Server (NTRS)

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.

Tabibi, Bagher M.; Lee, Ja H.

1991-01-01

21

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

NASA Technical Reports Server (NTRS)

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

Shiner, C. S.

1986-01-01

22

Solar-pumped laser for free space power transmission  

NASA Technical Reports Server (NTRS)

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.

Lee, Ja H.

1989-01-01

23

Advanced solar energy conversion. [solar pumped gas lasers  

NASA Technical Reports Server (NTRS)

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

Lee, J. H.

1981-01-01

24

Solar Pumped Laser Microthruster  

SciTech Connect

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

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

2010-10-08

25

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

NASA Technical Reports Server (NTRS)

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.

Shiner, C. S.

1985-01-01

26

Visible solar-pumped lasers  

NASA Astrophysics Data System (ADS)

We report on two visible solar pumped lasers; a red alexandrite laser with a potential tunability range between 700 and 818 nm, and a frequency doubled Nd:YAG laser operating at 532 nm. Highly concentrated solar energy was obtained by a 3-stage concentrator. An output power of up to 12 W was obtained from the alexandrite laser. The Q-switched Nd:YAG laser employed a type II KTP crystal for intracavity frequency doubling. Q-switching was obtained either passively or actively. In the passive Q-switching version, a water cooled Cr +4:YAG crystal was introduced into the laser cavity acting as both saturable absorber and laser rear mirror, and enforcing high repetition rate operation between 10 and 50 kHz. The average output power at 532 nm was 4.1 W. With an active acousto-optic modulator introduced between the laser rod and the high reflection rear mirror, the average output power at 532 nm and 7.3 kHz repetition rate was 8.7 W.

Lando, Mordechai; Shimony, Yehoshua; Benmair, Roth M. J.; Abramovich, Dov; Krupkin, Vladimir; Yogev, Amnon

1999-10-01

27

Feasibility of solar-pumped dye lasers  

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

28

Solar pumped lasers and their applications  

NASA Astrophysics Data System (ADS)

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

Lee, Ja H.

29

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual progress report, 1 January-30 June 1986  

SciTech Connect

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

Shiner, C.S.

1986-01-01

30

Solar-pumped gas laser development  

NASA Technical Reports Server (NTRS)

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

Wilson, J. W.

1980-01-01

31

Solar-pumped CO laser  

Microsoft Academic Search

This paper describes a method of converting thermal radiation directly into laser radiation at a wavelength of about 5 micrometers. The working fluid for the laser operation is a mixture of carbon monoxide and argon. The source of thermal radiation is assumed to be a solar oven or electrical oven operating in the range of 2000 to 2500 K. The

Charles E. Treanor

1986-01-01

32

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

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

Harries, W. L.

1982-01-01

33

Solar-pumped CO laser  

NASA Astrophysics Data System (ADS)

This paper describes a method of converting thermal radiation directly into laser radiation at a wavelength of about 5 micrometers. The working fluid for the laser operation is a mixture of carbon monoxide and argon. The source of thermal radiation is assumed to be a solar oven or electrical oven operating in the range of 2000 to 2500 K. The use of carbon monoxide as the lasing material presents the advantage that the absorbing lines can be pressure broadened to permit efficient absorption of the thermal radiation without unacceptable increases in vibrational relaxation. Estimates of the efficiency, size, and power loading of such a laser are discussed.

Treanor, Charles E.

34

Scaling studies of solar pumped lasers  

NASA Technical Reports Server (NTRS)

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

Christiansen, W. H.; Chang, J.

1985-01-01

35

Scaling studies of solar pumped lasers  

NASA Astrophysics Data System (ADS)

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

Christiansen, W. H.; Chang, J.

1985-08-01

36

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

NASA Technical Reports Server (NTRS)

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

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

1987-01-01

37

Solar pumped continuous wave carbon dioxide laser  

NASA Technical Reports Server (NTRS)

In an effort to demonstrate the feasibility of a solar pumped laser concept, gain has been measured in a CO2-He laser medium optically pumped by blackbody radiation. Various gas mixtures of CO2 and He have been pumped by blackbody radiation emitted from an electrically heated oven. Using a CO2 laser as a probe, an optical gain coefficient of 1.8 x 10 to the -3rd/cm has been measured at 10.6 microns for a 9:1 CO2-He mixture at an oven temperature of about 1500 K, a gas temperature of about 400 K and a pressure of about 1 torr. This corresponds to a small signal gain coefficient when allowance is made for saturation effects due to the probe beam, in reasonable agreement with a theoretical value.

Yesil, O.; Christiansen, W. H.

1978-01-01

38

Design and chemical synthesis of iodine-containing molecules for application to solar-pumped I* lasers. Semiannual Progress Report, 1 January-30 June 1985  

SciTech Connect

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.

Shiner, C.S.

1985-01-01

39

Theoretical studies of solar pumped lasers  

NASA Technical Reports Server (NTRS)

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.

Harries, Wynford L.

1990-01-01

40

Concepts for efficient high power solar pumped solid state lasers  

Microsoft Academic Search

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

H. Opower; F. Lindner; W. Zittel

1988-01-01

41

Power transmission using a solar-pumped laser  

NASA Astrophysics Data System (ADS)

A lab simulation which demonstrates the power beaming concept, based on solar pumped laser and photovoltaic cell, was performed. The simulation included a parabolic dish, a 3D CPC, a 2D CPC as a laser head for transmission and a photovoltaic cell for converting the laser light into electricity. A waveguide was used in order to obtain a uniform illumination upon the photovoltaic cell. A Nd:YAG laser rod was solar pumped using imaging and nonimaging systems producing 52 Watt laser at sun flux of 830 Watt/m2. In successive experiments the solar cell was exposed to a laser light using Nd:YAG and Alexandrite lasers. The efficiencies achieved were 33% laser to electricity efficiency for the Nd:YAG laser and approximately 40% for the Alexandrite.

Naftali, Nir; Pe'Er, Idit; Yogev, Amnon

1997-10-01

42

Overview and future direction for blackbody solar-pumped lasers  

NASA Technical Reports Server (NTRS)

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

Deyoung, R. J.

1988-01-01

43

Solar-pumped lasers for space power transmission  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

44

Efficiency of continuous-wave solar pumped semiconductor lasers  

NASA Astrophysics Data System (ADS)

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.

Johnson, Stanley; Kppers, Franko; Pau, Stanley

2013-04-01

45

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

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

Anderson, Neal G.

1992-01-01

46

Design of ultrahigh brightness solar-pumped disk laser.  

PubMed

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

Liang, Dawei; Almeida, Joana

2012-09-10

47

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

PubMed

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

Liang, Dawei; Almeida, Joana

2013-10-21

48

Solar Pumped High Power Solid State Laser for Space Applications  

NASA Technical Reports Server (NTRS)

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.

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

49

Solar-pumped electronic-to-vibrational energy transfer lasers  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

50

Direct solar pumping of semiconductor lasers: A feasibility study  

NASA Technical Reports Server (NTRS)

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

Anderson, Neal G.

1991-01-01

51

Highly efficient solar-pumped Nd:YAG laser.  

PubMed

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

Liang, Dawei; Almeida, Joana

2011-12-19

52

Solar-pumped solid state lasers for space - Space power transmission  

Microsoft Academic Search

Comparison of different laser types indicates that solar pumped solid state lasers are the best choice for space-space power transmission, taking into account the conversion efficiency of solar into laser radiation, the system masses, and suitable laser energy converters. Therefore, solid state lasers will be discussed in more detail with regard to system efficiency and thermal problems. The overall system

U. Brauch; H. Opower; W. Wittwer; J. Muckenschnabel

1991-01-01

53

Low-threshold solar-pumped laser using C2F5I  

NASA Technical Reports Server (NTRS)

Solar-pumped lasing was achieved with pentafluoroethyl iodide, C2F5I, a new alkyl-iodide. Output power and energy of 350 mW and 45 mJ were achieved. This lasant was found to have the lowest lasing threshold of any solar-pumped gas laser to date at approximately 100 solar constants. Such low threshold enables the use in space of simple, trough solar collectors.

De Young, R. J.; Weaver, W. R.

1986-01-01

54

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

NASA Astrophysics Data System (ADS)

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

Ogawa, Takayo; Wada, Satoshi; Higuchi, Mikio

2014-02-01

55

Passive Q-switching of high-power solar-pumped Nd:YAG laser  

Microsoft Academic Search

High power lasers operating at high repetition rates at the kilohertz regime are attractive for a variety of applications. Such high repetition rates can be achieved by Q-switching a cw laser using either an acousto-optic, an electro-optic or a passive Q-switch. Since passive Q-switching needs no external electric circuit, it may be valuable for solar pumped lasers to be used

Idit Pe'Er; Nir Naftali; Dov Abramovic; Yoram Noter; Amnon Yogev

1997-01-01

56

Improvement in solar-pumped Nd:YAG laser beam brightness  

NASA Astrophysics Data System (ADS)

Solar-pumped solid-state lasers are promising for renewable extreme-temperature material processing. Here we report a large improvement in solar laser beam brightness by pumping a thin Nd:YAG single crystal rod. A fused silica light guide of 14 mm22 mm rectangular cross-section is used to both transmit and homogenize the concentrated solar radiation from the focal zone of a 2.88 m2 parabolic mirror to the entrance aperture of a modified 2D-CPC flooded pump cavity, within which a 4 mm diameter rod is efficiently pumped. 2.2% slope efficiency is reached. Laser beam brightness figure of merit B is three times higher than that of the most recent solar-pumped Nd:YAG laser by a Fresnel lens. The introduction of the rectangular cross-section light guide has also ensured a much more stable laser emission than previous pumping schemes.

Almeida, J.; Liang, D.; Guillot, E.

2012-10-01

57

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

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

58

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

PubMed

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

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

2009-01-15

59

a 57 W Solar-Pumped Neodymium-Doped YAG Laser  

Microsoft Academic Search

An experiment conducted recently at the National Renewable Energy Laboratory has demonstrated world record efficiency for directly solar-pumped lasers. Using the High Flux Solar Furnace test facility and a tailored non -imaging secondary concentrator, a Nd:YAG crystal lased with a peak power of 57 +\\/- 1 W. With the primary mirror area of 12.12 m^2, each square meter of the

David Gerard Jenkins

1996-01-01

60

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

NASA Technical Reports Server (NTRS)

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

Williams, M. D.

1984-01-01

61

Performance of passive Q-switched, solar-pumped, high-power Nd:YAG lasers  

Microsoft Academic Search

Q-switched, solar-pumped, high power Nd:YAG lasers are attractive for a variety of applications requiring high instantaneous peak power density. The Q-switching can be obtained by an acousto-optic, electro-optic or passive device. Passive Q-switching seems an excellent choice for space as well as for other applications since it neither requires an external driver nor an electrical power supply. In recent years

Yoram Noter; Nir Naftali; Idit Pe'Er; Amnon Yogev; Mordechai Lando; Yehoshua Shimony

1997-01-01

62

High power CW iodine laser pumped by solar simulator  

NASA Technical Reports Server (NTRS)

An iodine photodissociation laser was pumped by a long Ar arc as the solar simulator to produce a 10-W CW output. Continuous lasing for 1 h was achieved with a flow of the laser material n-C3F7I. The 10-W CW output is the highest produced to date and establishes the feasibility of developing a solar-pumped laser for space power transmission.

Lee, Ja H.; Lee, Min H.; Weaver, Willard R.

1987-01-01

63

Threshold pump power of a solar-pumped dye laser  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

64

Kinetic modeling of an IBr solar pumped laser  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

65

Simulation model of a new solar pumped laser system of Fresnel lens in Helwan of Egypt  

NASA Astrophysics Data System (ADS)

A simulation model of a new solar pumped laser system is tested to be run in Helwan in Egypt as an example of an industrial polluted area. The system is based on concentrating the solar radiation using a Fresnel lens on a laser head fixed on a mount tracking the sun during the day and powered by a DC battery. The model is fed by real solar radiation data in the various seasons in order to know the laser power got from such a system in those conditions. The results showed that the output laser power obtained from this system can be up to 6.2 W in spring, 6.8 W in summer, 2.2 W in autumn and 0.4 W in winter.

Abdel-Hadi, Yasser A.

2012-12-01

66

Thermal analysis in a solar pumped laser for Mg energy cycle  

NASA Astrophysics Data System (ADS)

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.

Bagheri, Behgol; Uchidat, Shgeaki

2012-10-01

67

Flashlamp-pumped iodine monobromide laser characteristics  

NASA Technical Reports Server (NTRS)

The operating characteristics of a flashlamp-pumped IBr laser were investigated to evaluate its suitability for solar-pumped laser applications. A peak power of 350 W/sq cm at 2.7 microns was achieved at 12-torr IBr pressure. At 500-J flashlamp energy, the IBr output saturated; a gain of 0.17% per cm was measured for IBr. Neon was found to be effective for enhancing the recombination of the photodissociation products. With neon as a buffer gas, the laser pulse length was extended to 53 microsec. The termination of the laser pulse, within the flashlamp pulse, is thought to be due to the temperature rise in the gas. Increasing the IBr initial temperature decreased the lasing output. At 300 C, output dropped to approximately one-half the room temperature value. The dominant quencher is thought to be atomic iodine. IBr was found to couple better to the flashlamp energy than C3F7I.

Zapata, L. E.; De Young, R. J.

1983-01-01

68

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

69

Comparison of Solar Pumped Nd:YAG and Nd:Cr:GSGG Lasers at Liquid Nitrogen and Room Temperature.  

National Technical Information Service (NTIS)

The comparison of solar pumped laser oscillators made of Nd:YAG and Nd:Cr:GSGG rods was carried out at 77 and 300 K. The comparison included the powers achieved at various output coupling mirrors and a study of the beam divergence. The study shows that go...

U. Brauch J. Muckenschnabel A. Yogev R. Benmair Y. Noter

1989-01-01

70

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

71

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

PubMed

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

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

2014-04-20

72

High-efficiency solar-pumped laser with a grooved Nd:YAG rod.  

PubMed

We test the performances of a Nd:YAG rod with a grooved sidewall in two solar pumped laser setups. In both cases, a Fresnel lens with a surface of 1.03??m2 is used as the primary solar light concentrator. In the first setup, a ceramic conical cavity is used as the secondary concentrator. Maximum output power of 20.3W is obtained, corresponding to a slope efficiency of laser output power with respect to focused solar power of 8.34%. In the second setup, a water tube lens is added in a copper conical cavity to further increase the solar energy concentration; from this setup, 27W output power is obtained, the slope efficiency of laser output power with respect to focused solar power is 9%. In both cases, the performances of the grooved rod are compared with those of an unpolished rod. The efficiency and the beam quality with the grooved rod are superior to those of the unpolished rod. PMID:24979426

Xu, Peng; Yang, Suhui; Zhao, Changming; Guan, Zhu; Wang, Huaxin; Zhang, Yichen; Zhang, Haiyang; He, Tao

2014-06-20

73

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

NASA Technical Reports Server (NTRS)

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

Monson, D. J.

1978-01-01

74

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

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

75

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

NASA Astrophysics Data System (ADS)

Since the first reported Nd:YAG solar laser, researchers have been exploiting parabolic mirrors and heliostats for enhancing laser output performance. We are now investigating the production of an efficient solar-pumped laser for the reduction of magnesium from magnesium oxide, which could be an alternative solution to fossil fuel. Therefore both high conversion efficiency and excellent beam quality are imperative. By using a single fused silica light guide of rectangular cross section, highly concentrated solar radiation at the focal spot of a stationary parabolic mirror is efficiently transferred to a water-flooded V-groove pump cavity. It allows for the double-pass absorption of pump light along a 4mm diameter, 30mm length, 1.1at% Nd:YAG rod. Optimum pumping parameters and solar laser output power are found through ZEMAXTM non-sequential ray-tracing and LASCADTM laser cavity analysis. 11.0 W of multimode laser output power with excellent beam profile is numerically calculated, corresponding to 6.1W/m2 collection efficiency. To validate the proposed pumping scheme, an experimental setup of the double-stage light-guide/V-groove cavity was built. 78% of highly concentrated solar radiation was efficiently transmitted by the fused silica light guide. The proposed pumping scheme can be an effective solution for enhancing solar laser performances when compared to other side-pump configurations.

Almeida, Joana; Liang, Dawei

2011-05-01

76

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

SciTech Connect

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.

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

1987-09-01

77

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

Microsoft Academic Search

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

L. E. Zapata; M. D. Williams

1989-01-01

78

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

79

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

PubMed

We propose a simple and efficient pumping approach for a high-power solar-pumped laser by using a liquid light-guide lens (LLGL) and a hybrid pumping cavity. A 22 m Fresnel lens is used as a primary concentrator to collect natural sunlight; 120 W cw laser power and a 4.3% total slope efficiency are achieved with a 6-mm diameter Nd:YAG rod within a 14-mm diameter LLGL. The corresponded collection efficiency is 30.0 W/m(2), which is 1.5 times larger than the previous record. This result is unexpectedly better than that of Cr:Nd:YAG ceramics. It is because the scattering coefficient of Cr:Nd:YAG ceramics is 0.004cm(1), which is 2 times larger than that of the Nd:YAG crystal, although both have similar saturation gains. PMID:22743490

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

2012-07-01

80

Micro Chemical Oxygen-Iodine Laser (COIL).  

National Technical Information Service (NTIS)

It has been previously proposed to improve the performance and compactness of chemical oxygen-iodine lasers (COIL) through the replacement of some of their macroscale components with arrays of higher-performing microscale (MEMS) components. In this progra...

C. Livermore-Clifford

2007-01-01

81

Overview of iodine generation for oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

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

Jirsek, Vt.

2012-01-01

82

A model for a continuous-wave iodine laser  

NASA Technical Reports Server (NTRS)

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.

Hwang, In H.; Tabibi, Bagher M.

1990-01-01

83

Electric Oxygen Iodine Laser: A Study for Scaling.  

National Technical Information Service (NTIS)

Energy transfer reactions that could potentially limit scaling of the electric oxygen iodine laser (EOIL) were examined. Quenching of excited iodine atoms (I*) by atomic oxygen has been identified as a significant energy loss channel. The rate constant fo...

M. C. Heaven

2009-01-01

84

High-power oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

At VNIIEF work on chemical oxygen-iodine laser (COIL) was begun in 1982 at the Laboratory of Gas-Flow Chemical Lasers. The present report is a review of work performed at this laboratory, the same year generation at the 10 mW level was obtained. A year later the output power was increased up to 180 W. In 1986 optimization of the set-up operation allowed us to increase the laser power up to 900 W. Later a new research set-up was created. In 1990 it produced the output power of approximately 4 kW in 20 seconds.

Kalinovsky, Vitali S.; Kirillov, Gennadi A.; Konovalov, V. V.; Nikolaev, V. D.

1993-04-01

85

Advanced iodine laser for high intensity interactions  

SciTech Connect

The results concerning laser radiation source development capable of focusing radiation into a region of wavelength order designated for obtaining the quasistationary ({tau}{approx}10{sup -9}-10{sup -10} s) fields with strength of 10{sup 9}-10{sup 10} V/cm to investigate atoms behavior in such fields are presented. To solve this problem the iodine laser with the pulse energy of 10{sup 2}-10{sup 4} J is used. Radiation is focused by the objective {approx}1:1. The phase conjugation mirror compensates aberrations of laser beam and optical elements. Under such conditions the radiation intensity in the focal region is expected to be 10{sup 19}-10{sup 21} W/cm{sup 2}.

Kulikov, S. M.; Dolgopolov, Y. V.; Dudov, A. M.; Eroshenko, V. A.; Kochemasov, G. G.; Pevny, S. N.; Rukavishnikov, N. N.; Smirnov, A. B.; Smyshlyaev, S. P.; Sukharev, S. A.; Shkapa, A. F. [Russian Federal Nuclear Center (VNIIEF), Sarov 607190, Nizhni Novgorod Region (Russian Federation)

1997-04-15

86

The standard chemical oxygen-iodine laser kinetics package  

Microsoft Academic Search

This report presents the Air Force Weapons Laboratory Standard Chemical Oxygen-Iodine Laser Kinetics Package. A complete reaction scheme including recommended rate coefficients for modeling the gas phase kinetics of chemical oxygen-iodine lasers (COIL) was established to provide a common basis for the research and development of COIL devices. A review of the experimental kinetic data base from which this model

Glen P. Perram; Gordon D. Hager

1988-01-01

87

Solar-simulator-pumped atomic iodine laser kinetics  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

88

High-power iodine lasers with phase conjugation  

Microsoft Academic Search

The operations at VNIIEF large-sized laser facilities and the VNIIEF advanced projects of laser facilities for ICF and fundamental physics investigations are discussed. Iodine laser and phase conjugation physics are treated. The possibility of the monopulse laser channel development is shown with energy up to 70 kJ in the single beam. The paper presents the brief review of the 10

Gennadiy G. Kochemasov; Stanislav M. Kulikov; Stanislav A. Sukharev

1996-01-01

89

Oxygen-iodine laser in Russian Federal Nuclear Center VNIIEF  

Microsoft Academic Search

The paper reports on the experimental investigations into supersonic oxygen-iodine laser (COIL). Study efficiency results of the COIL unit driven by the singlet oxygen generator (SOG) with twisted gas flow (TA-SOG) are given for supersonic iodine- oxygen mixing at a broadly ranged singlet oxygen pressure and buffer gas flowrate. The measurements were performed for variations of the throat sizes and

Boris A. Vyskubenko; Anatoly A. Adamenkov; Victor V. Bakshin; Vladimir V. Buzoverya; Leonid A. Vdovkin; Yuri N. Deryugin; Valentin I. Efremov; Sergey P. Ilyin; Vladimir V. Kalinovskiy; Yuriy V. Kolobyanin; Vladimir V. Konovalov; Evgeniy A. Kudryashov; Vladimir B. Moiseev; Victor D. Nickolaev

2005-01-01

90

Space interferometry application of laser frequency stabilization with molecular iodine.  

PubMed

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

Leonhardt, Volker; Camp, Jordan B

2006-06-10

91

High-power iodine lasers with phase conjugation  

NASA Astrophysics Data System (ADS)

The operations at VNIIEF large-sized laser facilities and the VNIIEF advanced projects of laser facilities for ICF and fundamental physics investigations are discussed. Iodine laser and phase conjugation physics are treated. The possibility of the monopulse laser channel development is shown with energy up to 70 kJ in the single beam. A brief review is presented of a 10 MJ laser project and the high explosive iodine laser (HE-laser) with phase conjugation is considered as the possible means of solving the ICF problem in the fast ignition concept. We suggest the way of quasi stationary superhigh light field production by the focusing power of laser beams into supersmall volume (wavelength orders size).

Kochemasov, Gennadiy G.; Kulikov, Stanislav M.; Sukharev, Stanislav A.

1996-02-01

92

High-power iodine lasers with phase conjugation  

NASA Astrophysics Data System (ADS)

The operations at VNIIEF large-sized laser facilities and the VNIIEF advanced projects of laser facilities for ICF and fundamental physics investigations are discussed. Iodine laser and phase conjugation physics are treated. The possibility of the monopulse laser channel development is shown with energy up to 70 kJ in the single beam. The paper presents the brief review of the 10 MJ laser project and the high explosive photodissociated iodine laser (HE- laser) with phase conjugation is considered as the possible way of solving the ICF problem in the fast ignition concept. We suggest the way of the quasi stationary superhigh light field production by the focusing of power laser beams into supersmall volume (wavelength order size).

Kochemasov, Gennadiy G.; Kulikov, Stanislav M.; Sukharev, Stanislav A.

1996-04-01

93

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

NASA Technical Reports Server (NTRS)

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.

Cobb, Stephen H.

1991-01-01

94

Gain and Temperature in a Slit Nozzle Supersonic Chemical Oxygen-Iodine Laser with Transonic and Supersonic Injection of Iodine.  

National Technical Information Service (NTIS)

Spatial distributions of the gain and temperature 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 ra...

B. D. Barmashenko D. Furman E. Bruins S. Rosenwaks V. Rybalkin

2002-01-01

95

Oxygen-iodine laser research at RFNC-VNIIEF  

Microsoft Academic Search

The paper presents the most important efforts in the Chemical Oxygen-Iodine Laser (COIL) research carried on at Russian Federal Nuclear Center VNIIEF and some of their results. In particular, they include experimental data on the laser generation output of subsonic COIL on the water vapor concentration in singlet oxygen, calculated generation values of a supersonic COIL having high singlet oxygen

Anatoliy A. Adamenkov; Yuri N. Deryugin; Boris A. Vyskubenko; S. P. Ilyin; V. V. Kalinovsky; Yuriy V. Kolobyanin; V. V. Konovalov; Ivan M. Krukovsky; Evgeniy A. Kudryashov; V. D. Nikolaev

1998-01-01

96

A portable iodine stabilized helium-neon laser  

Microsoft Academic Search

A newly designed iodine stabilized helium-neon (He-Ne) laser is described which is stable to 3 x 10 to the -13th (1000-s sample time) but which exhibits an intensity dependent shift of about 8 kHz\\/W-sq cm. Closer agreement between dissimilar lasers is attained when the internal power densities are approximately equal.

Howard P. Layer

1980-01-01

97

Precision Wavelength Comparisons of Iodine-Stabilized Lasers  

NASA Astrophysics Data System (ADS)

The wavelengths of an Ar+ laser and of a He-Ne laser at 515 nm and 612 nm, respectively, have been compared with the wavelength of a He-Ne laser at 633 nm. All the lasers involved were stabilized by using saturated absorption in iodine-127. The wavelength ratios were related to the He-Ne laser at 633 nm stabilized to the hyperfine component i of the rotational and vibrational transition R(127) 11-5 of iodine. For the Ar+ laser locked to the component a3 of the P(13) 43-0 line, the ratio determined was ?a3/?i = 0.813 081 2954 (1 +/- 5 . 10-10) and for the 612 nm He-Ne laser locked to the component o of the R(47) 9-2 line, the measured ratio was ?o/?i = 0.966 791 6050 (1 +/- 3 . 10-10).

Bnsch, G.

1983-01-01

98

Oxygen-iodine laser in Russian Federal Nuclear Center VNIIEF  

NASA Astrophysics Data System (ADS)

The paper reports on the experimental investigations into supersonic oxygen-iodine laser (COIL). Study efficiency results of the COIL unit driven by the singlet oxygen generator (SOG) with twisted gas flow (TA-SOG) are given for supersonic iodine- oxygen mixing at a broadly ranged singlet oxygen pressure and buffer gas flowrate. The measurements were performed for variations of the throat sizes and the positions of the iodine injection plane in supersonic nozzle part. The gas pressure at the input of the nozzle unit was varied from 50 to 150 Torr. The chemical efficiency achieved under optimal operational COIL conditions was 33%.

Vyskubenko, Boris A.; Adamenkov, Anatoly A.; Bakshin, Victor V.; Buzoverya, Vladimir V.; Vdovkin, Leonid A.; Deryugin, Yuri N.; Efremov, Valentin I.; Ilyin, Sergey P.; Kalinovskiy, Vladimir V.; Kolobyanin, Yuriy V.; Konovalov, Vladimir V.; Kudryashov, Evgeniy A.; Moiseev, Vladimir B.; Nickolaev, Victor D.

2005-03-01

99

Oxygen-iodine laser research at RFNC-VNIIEF  

NASA Astrophysics Data System (ADS)

The paper presents the most important efforts in the Chemical Oxygen-Iodine Laser (COIL) research carried on at Russian Federal Nuclear Center VNIIEF and some of their results. In particular, they include experimental data on the laser generation output of subsonic COIL on the water vapor concentration in singlet oxygen, calculated generation values of a supersonic COIL having high singlet oxygen pressure at the nozzle inlet, and experiments with the twisted-aerosol- flow singlet oxygen generator (TASOG) for up to 100 Torr pressures. Requirements are discussed for the supersonic high- pressure COIL components, such as singlet oxygen generator and the system for singlet oxygen mixing with iodine.

Adamenkov, Anatoliy A.; Deryugin, Yuri N.; Vyskubenko, Boris A.; Ilyin, S. P.; Kalinovsky, V. V.; Kolobyanin, Yuriy V.; Konovalov, V. V.; Krukovsky, Ivan M.; Kudryashov, Evgeniy A.; Nikolaev, V. D.

1998-12-01

100

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

101

Advancement and problems of fullerene-oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

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

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

2010-01-01

102

Iodine  

MedlinePLUS

... the following: Fish (such as cod and tuna), seaweed, shrimp, and other seafood, which are generally rich ... iodine. Dietary supplements of iodine-containing kelp (a seaweed) are also available. Am I getting enough iodine? ...

103

Absorption of iodine laser pulses in potassium and cesium vapors  

Microsoft Academic Search

The absorption of ns iodine laser pulses at a wavelength of 1.315 mum in potassium and cesium vapors has been measured. At elevated temperature there is considerable absorption in both vapors. The absorption was not saturable at intensities up to 1 GW\\/cm2, but increased with increasing intensity.

Ernst E. Fill

1980-01-01

104

Molecular Iodine Fluorescence Using a Green Helium-Neon Laser  

ERIC Educational Resources Information Center

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

Williamson, J. Charles

2011-01-01

105

Broadband OPCPA pumped by ultra-narrowband gaseous iodine laser  

NASA Astrophysics Data System (ADS)

Amplification of femtosecond pulses using an ultra-narrowband gaseous pulse laser was demonstrated for the first time. A single-shot sub-nanosecond iodine photodissociation laser with a bandwidth of 20 pm was used as a driver in an allstage OPCPA. An externally triggerable OPO tuned to laser line of 1315.24 nm was used in the front end of the iodine laser. Frequency tripled beam at 438 nm was used to pump parametric amplifiers, LBO and KDP crystals. The signal pulses from a Ti:sapphire laser at the central wavelength of 800 nm with a bandwidth of 70 nm (FWHM) were stretched from 12.5 fs to 250 ps and amplified by a factor of 2108. The amplified pulses of typical bandwidth of 50 nm were compressed down to 27 fs. The output power of 0.5 TW was achieved. An optimized amplifier chain and addition of a third nonlinear crystal would enable to generate femtosecond pulses of several terawatts. The broadband pulses at 800 nm central wavelength were amplified in the KDP crystal for the first time, due to the suitable wavelength of the pump pulses. Availability of large aperture KDP crystals promises the generation of petawatt beam at kJ iodine laser facilities.

Novk, O.; Tur?i?ov, H.; Divok, M.; Smr, M.; Huynh, J.; Straka, P.

2012-02-01

106

Chemical oxygen iodine laser (COIL) technology and development  

NASA Astrophysics Data System (ADS)

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

Duff, Edward A.; Truesdell, Keith A.

2004-09-01

107

XeCl laser pumped iodine laser using t-C4F9I  

NASA Technical Reports Server (NTRS)

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.

Hwang, In Heon; Han, Kwang S.

1989-01-01

108

Iodine  

USGS Publications Warehouse

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.

Krukowski, S. T.

2006-01-01

109

Nuclear-driven flashlamp pumping of the atomic iodine laser  

SciTech Connect

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

Miley, G.H.

1992-03-01

110

Nuclear-driven flashlamp pumping of the atomic iodine laser  

NASA Astrophysics Data System (ADS)

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.

Miley, G. H.

1992-03-01

111

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

SciTech Connect

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

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

2005-06-30

112

Experiment on iodine transmutation by laser Compton scattering gamma ray  

NASA Astrophysics Data System (ADS)

A laser Compton scattering gamma-ray based nuclear transmutation is proposed to reduce the hazards of long-lived activity nuclear waste. In accordance with this proposal, a laser Compton scattering gamma-ray facility has been built on NewSUABARU storage ring. The facility provides 17.6 MeV gamma-ray photons, which is applicable to the nuclear transmutation research. In order to investigate the reaction rate of Iodine material, the 23Na127I target is adopted for the irradiation experiment. The results show that the experimental data is close to the simulation result.

Li, D.; Imasaki, K.; Miyamoto, S.; Horikawa, K.; Amano, S.; Mochizuki, T.

2008-05-01

113

Development of the electric discharge oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

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

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

2007-05-01

114

Laser transition in atomic iodine for passive and active SETI  

NASA Astrophysics Data System (ADS)

It is proposed to use the wavelength 1.315 ?m of the laser transition 2P 1/2? 2P 3/2 in atomic iodine both for passive and active SETI. The search for an extraterrestrial signal at this wavelength is promising because an active quantum filter (AQF) with a quantum sensitivity limit and with strong fixing in the spectrum luminescence line of the width less than 0.01 cm -1, has been developed for the noted wavelength. Such AQF is capable of receiving the laser signals, consisting of only a few photons, against the background of emission from a star under study. In addition, the high-energy iodine lasers emitting diffraction-limited nanosecond pulses of energy of 2 kJ in a single beam at the wavelength 1.315 ?m have been created. The spectral tuning of radiation of these lasers allows one to compensate the frequency Doppler shift. A weak absorption of the 1.315 ?m radiation in the Earth atmosphere allows the search for extraterrestrial signals by using the ground optical telescopes equipped with adaptive optical systems.

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

2010-12-01

115

Chemical oxygen-iodine laser (COIL) thermal management  

NASA Astrophysics Data System (ADS)

The chemical oxygen-iodine laser (COIL) has been studied at the Phillips Laboratory since its invention in 1978. One of the most difficult challenges in COIL technology is to produce constant power for more than a few seconds; an essential feature for most applications. The key to developing a laser with these operational characteristics is management of the heat released during the production of singlet delta oxygen. Approximately 10 joules is deposited into the singlet delta oxygen generator (SOG) for every joule extracted as laser power. A recent test series demonstrated run times of 120 seconds at 9 kW by controlling the SOG reaction temperature with a flowing aqueous solution of cold hydroperoxide (BHP). This method of managing the energy released is quite effective but requires a large reservoir of cold BHP.

Truesdell, Keith A.; Helms, Charles A.; Longergan, Thomas; Wisniewski, Charles F.; Scott, Joseph E.; Healey, Keith P.

1995-03-01

116

Applications of the chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

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.

Latham, William P.; Kendrick, Kip R.; Quillen, Brian

2000-01-01

117

Transient regime of stimulated enthalpy scattering of light by ultrasound in iodine lasers  

SciTech Connect

A theoretical investigation is made of the transient regime of stimulated enthalpy scattering of light by ultrasound in iodine lasers. The distinguishing characteristics of such scattering are identified. A comparative analysis is made of the stability of working mixtures of iodine lasers under conditions of stimulated enthalpy scattering and ways of verifying experimentally the theoretical results are considered.

Zuev, V.S.; Korol'kov, K.S.; Nosach, O.Y.; Orlov, E.P.

1984-09-01

118

Iodine  

MedlinePLUS

... Diatomique, Iode Molculaire, Iode Mono-atomique, Iode de Povidone, Iode de Sodium, Iodide, Iodized Salt, Iodure, Iodure ... Numro atomique 53, Periodate de Sodium, Potassium Iodide, Povidone Iodine, Saturated Solution Potassium Iodide, Sel Iod, Sodium ...

119

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

In any lasing medium the emission wavelength should be chosen where there is little self absorption. As emission and absorption spectra for metallic vapors did not seem available, therefore, estimates were made of these cross sections for sodium vapor as functions of wavelength. Although absolute values were not obtained, information on where the emission wavelength should occur became evident. The method of obtaining quantities proportional to the cross sections versus wavelength is outlined. A further comparison based on alternative expressions for the absorption and emission cross sections over a limited wavelength range is made.

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

1984-01-01

120

Theoretical studies of solar-pumped lasers  

NASA Technical Reports Server (NTRS)

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

Harries, Wynford L.

1988-01-01

121

Theoretical studies of solar-pumped lasers  

NASA Astrophysics Data System (ADS)

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

Harries, Wynford L.

1988-06-01

122

Power laser beaming and applications in space  

NASA Technical Reports Server (NTRS)

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.

Lee, Ja H.; Conway, Edmund J.

1991-01-01

123

Standard chemical oxygen-iodine laser kinetics package. Revision. Final report, August 1987March 1988  

Microsoft Academic Search

It has been long recognized that continuous-wave (CW) chemical lasers represent an extremely complex interaction between fluid mechanics, chemical kinetics, and optical physics. The chemical oxygen-iodine laser presents additional problems in that the energy-storage medium, singlet oxygen, is generated by a liquid-gas phase reaction. The kinetics of chemical oxygen-iodine lasers can be divided into five categories: (1) the chemistry of

G. P. Perram; G. D. Hager

1988-01-01

124

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

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

125

Threshold kinetics of a solar-simulator-pumped iodine laser  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

126

Pulse propagation in the amplifier of a high-power iodine laser  

Microsoft Academic Search

Pulse propagations in an amplifier in the case of the photodissociation iodine laser are investigated with the use of semiclassical treatments, especially when the input pulse fed into the amplifier has a width comparable to or shorter than the transverse relaxation time of the amplifier medium. In our semiclassical equations for pulse propagation in an iodine amplifier, the populations of

HIDEAKI SAITO; T. Uchiyama; T. Fujioka

1978-01-01

127

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

NASA Astrophysics Data System (ADS)

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

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

2003-06-01

128

Advanced Nozzle Concepts for the Chemical Oxygen-Iodine Laser (COIL).  

National Technical Information Service (NTIS)

This report results from a contract tasking P. N. Lebedev Physical Institute as follows: Iodine lasers offer the possibility of producing high average powers at a wavelength compatible with conventional fiber optic delivery systems, making them attractive...

V. D. Nikolaev

2006-01-01

129

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

NASA Technical Reports Server (NTRS)

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.

Mcdaniel, J. C., Jr.

1982-01-01

130

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

NASA Astrophysics Data System (ADS)

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.

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

2002-05-01

131

Standard Chemical Oxygen-Iodine Laser Kinetics Package. Final report, August 1987March 1988  

Microsoft Academic Search

This report presents the Air Force Weapons Laboratory Standard Chemical Oxygen-Iodine Laser Kinetics Package. A complete reaction scheme including recommended rate coefficients for modeling the gas-phase kinetics of chemical oxygen-iodine lasers (COIL) was established to provide a common basis for the research and development of COIL devices. A review of the experimental kinetic data base from which this model was

G. P. Perram; G. D. Hager

1988-01-01

132

A 12-kW continuous-wave chemical oxygen-iodine laser  

SciTech Connect

A 12-kW continuous-wave chemical oxygen-iodine laser, provided with an original jet-type singlet oxygen generator, is developed and tested. The experimental and numerical techniques applied for the diagnostics and mathematical simulation of processes in the laser active medium are introduced. Some of the calculation and experimental results are presented. (lasers)

Boreysho, A S; Mal'kov, V M; Savin, Aleksandr V; Vasil'ev, D N; Evdokimov, I M; Trilis, A V; Strakhov, S Yu [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2003-04-30

133

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

Microsoft Academic Search

The overview of experimental research aimed at the research and development of an electric discharge oxygen-iodine laser (DOIL) since the first negative attempt of launching a DOIL in the 1970's is presented. The problem is tightly connected with the development of singlet delta oxygen (SDO) electric generator, which could substitute in future for SDO chemical one used for a high-power

Andrey Ionin

2006-01-01

134

PHYSICAL PROCESSES IN LASERS AND CONTROL OF LASER RADIATION PARAMETERS: Influence of a quenching agent on parameters of stimulated enthalpy scattering in iodine photodissociation lasers  

NASA Astrophysics Data System (ADS)

An analysis is made of the influence of quenching of excited iodine on the parameters of stimulated enthalpy scattering in iodine photodissociation lasers. It is shown that the stability of the active mixtures of these lasers during evolution of stimulated scattering by thermal waves may be improved by selecting a suitable quenching agent and a suitable concentration.

Orlov, E. P.

1989-04-01

135

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

NASA Astrophysics Data System (ADS)

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

Zhou, Songqing; Qu, Pubo; Ren, Weiyan

2013-05-01

136

Laser fusion investigations on high-power photodissociation iodine lasers ISKRA  

NASA Astrophysics Data System (ADS)

At VNIIEF laser fusion investigations are based on photodissociation iodine lasers (the wavelength of radiation (lambda) equals 1.315 micrometers ). The main goals of the investigations are determination of ignition conditions, choice of target types, laser interaction regime, energy and other necessary characteristics. Beginning in 1980 we conducted experiments on irradiation of targets of different types on the one-channel four-beam facility ISKRA-4 producing 10 TW. In the last years ISKRA-4 was upgraded: we realized conversion to the second harmonic and introduced the eight-beam irradiation system. Experiments at the second harmonic yielded 1 kJ of energy and 3 TW of power. In 1989 we built and put into operation the 12-channel facility ISKRA-5 producing energy up to 30 kJ and power up to 120 TW. In 1990 we began a series of target irradiation experiments on this facility. The present work is a review of laser fusion investigations conducted on the facilities ISKRA-4 and ISKRA-5. It contains a brief description of the facilities and of some specific phenomena which occur during monopulse amplification in high-power iodine lasers. Considerable attention is paid to problems of direct-drive targets and experimental results obtained on ISKRA-4 which are given in comparison with the data of model calculations. The work is concluded with the results of first experiments on irradiation of targets with a reversed corona which were conducted on the facility ISKRA-5.

Kochemasov, Gennadiy G.

1993-04-01

137

1.8 watt cw atomic iodine photolysis laser at 1.315 micron  

NASA Astrophysics Data System (ADS)

A 1.8 watt cw photolytically excited atomic iodine laser at 1.315 micron is reported. This power is believed to be the highest level obtained via the cw photolysis of an alkyl-iodide gas like C3F7I. The enhanced laser performance was achieved using a cw microwave excited ultraviolet lamp for the laser's excitation and longitudinal flow for the removal of the quenching by-product I2. Over an excitation length of 25 cm, an average small signal gain coefficient of 2 percent/cm was produced and using a stable resonator, many higher order transverse modes were observed. Its easy operation and high power may make this iodine laser very useful for the experimental testing of peripheral iodine laser technologies.

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

1988-05-01

138

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

NASA Technical Reports Server (NTRS)

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.

Tabibi, Bagher; Venable, Demetrius D.

1989-01-01

139

HE-pumped iodine laser for plasma and high intensity interactions  

SciTech Connect

The amplifier channel energetics of high power iodine laser pumped by the radiation of shock wave front is treated. Conditions are discussed when super-high light field can be obtained by focusing the phase-conjugation of laser radiation. {copyright} {ital 1996 American Institute of Physics.}

Kirillov, G.A.; Kochemasov, G.G.; Kulikov, S.M.; Pevny, S.N.; Sukharev, S.A. [Russian Federal Nuclear Center (VNIIEF), 607200, Arzamas-16, Nizhni Novgorod Region (Russia)

1996-05-01

140

Method, System and Apparatus for an Enhanced Electrically Pumped Oxygen Iodine Laser.  

National Technical Information Service (NTIS)

In one embodiment of the present invention an oxygen iodine laser includes a gas mixing section. Ground state oxygen and a carrier gas are introduced into the first gas mixing section, sometimes separately. The laser includes a discharge region to generat...

D. L. Carroll D. M. King J. T. Verdeyen W. C. Solomon

2005-01-01

141

Optimization of jet singlet oxygen generator for chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Experimental investigation of a jet singlet oxygen generator for a supersonic chemical oxygen-iodine laser was performed aimed to evaluation of the effects of BHP temperature and composition on the water content and other output generator parameters. Laser experiments on a small-scale system were realized to prove the obtained results.

Spalek, Otomar; Kodymova, Jarmila; Zagidullin, Marsel V.; Nikolaev, Valeri D.

1997-04-01

142

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

NASA Astrophysics Data System (ADS)

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.

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

143

Temperature measurement in a compressible flow field using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

The thermometric capability of a two-line fluorescence technique using iodine seed molecules in air is investigated analytically and verified experimentally in a known steady compressible flow field. Temperatures ranging from 165 to 295 K were measured in the flowfield using two iodine transitions accessed with a 30-GHz dye-laser scan near 543 nm. The effect of pressure broadening on temperature measurement is evaluated.

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

1987-01-01

144

Multiphoton ionization of iodine atoms and CF 3I molecules by XeCl laser radiation  

NASA Astrophysics Data System (ADS)

We report about effective ionization of iodine atoms and CF3I molecules under the action of intense XeCl laser radiation (308 nm). The only ion fragment resulting from the irradiation of the CF3I molecules is the I+ ion. We have studied the influence of the intensity, spectral composition, and polarization of the laser radiation used on the intensity of the ion signal and the shape of its time-of-flight peak. Based on the analysis of the results obtained, we have suggested the mechanism of this effect. The conclusion drawn is that the ionization of the iodine atoms by the ordinary XeCl laser with a nonselective cavity results from a three- (2 + 1)-photon REMPI process. This process is in turn due to the presence of accidental two-photon resonances between various spectral components of the laser radiation and the corresponding intermediate excited states of the iodine atom. The probability of ionization of the atoms from their ground state I(2P3/2) by the radiation of the ordinary XeCl laser is more than two orders of magnitude higher than the probability of their ionization from the metastable state I*(2P1/2). The ionization of the CF3I molecules by the XeCl laser radiation occurs as a result of a four-photon process involving the preliminary one-photon dissociation of these molecules and the subsequent (2 + 1)-photon REMPI of the resultant neutral iodine atoms.

Lokhman, V. N.; Ogurok, D. D.; Ryabov, E. A.

2008-01-01

145

LASERS: Efficient chemical oxygen iodine laser with a high total pressure of the active medium  

NASA Astrophysics Data System (ADS)

A new concept of obtaining a high total pressure of the active medium of a chemical oxygen iodine laser (OIL) is proposed and verified. The nozzle unit of the laser consists of the alternating vertical arrays of cylindrical nozzles to produce high-pressure nitrogen jets, plane slotted nozzles for the flow of O2(1?) oxygen, and vertical arrays of cylindrical nozzles to inject the N2 I2 mixture between the first two streams. For a molar chlorine flow rate of 39.2 mmol s-1, the output power was 700 W and the chemical efficiency was 19.7 %. The combined use of the ejector nozzle unit proposed to obtain the active medium and a super-sonic diffuser allows a significant simplification of the ejection system for the exhaust active medium of the OIL.

Zagidullin, M. V.; Nikolaev, V. D.; Svistun, M. I.; Khvatov, N. A.; Heiger, G. D.; Madden, T. J.

2001-01-01

146

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

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

147

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

NASA Astrophysics Data System (ADS)

The paper reports on experimental studies of the active medium gain in supersonic electric-discharge oxygen-iodine laser (DOIL) based on traveling mw discharge. The measurements have included: absolute concentration, yield, and energy efficiency of production of SO in pure oxygen and oxygen-helium mixes at an oxygen partial pressure 3 to 15 Torr. For the gas flow to get rid of atomic oxygen, both heterogeneous mercury oxide coatings of the tube walls and homogeneous additives to the work mix, such as nitrogen oxide, have been used. The active medium of DOIL was formed using a nozzle array of the type of ejector sized as 10*50 mm2. The singlet oxygen-helium mix was supplied through three rows of sonic cylindrical nozzles, while the iodine-carrier gas mix - through two rows of supersonic conical nozzles with a half-opening angle of 10(arc). The gas-phase iodine was produced in a quartz cell filled with iodine crystals. Room-temperature iodine vapors were picked up with a carrier gas (nitrogen or helium) and thus delivered into the nozzle array. The active medium was investigated by the high-resolution laser diode spectroscopy approach that used the laser type Vortex 6025 purchased from New Focus, Inc. The laser medium gain factor was determined by the intra-cavity approach having a sensitivity about 1*10-6 cm-1. The static temperature of the medium was determined from the measurements of gain half-width. The gain of the active medium of electric-discharge OIL has been investigated. The DOIL in use was operating on a mix composed as O2:He=1:1 at a total pressure of 6 Torr and flowrate - about 1 mmol/s. With helium as an iodine carrier gas at a flowrate ~3 mmol/s, we have recorded a positive gain in the DOIL medium.

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

2007-05-01

148

Planar Laser-Induced Iodine Fluorescence Technique for Flow Visualization and Quantitative Measurements in Rarefied Flows  

NASA Astrophysics Data System (ADS)

Planar Laser-Induced Iodine Fluorescence (PLIIF) is a powerful nonintrusive technique for flow visualization and quantitative measurements in continuum and rarefied flows. The technique provides measurements of multiple flowfield parameters in a cross-sectional plan of the flow. A theoretical model of the PLIIF is given, followed by details of the experiments, results and comparison with calculations.

McDaniel, James; Cecil, Eric; Reed, Erin; Codoni, Josh; Boyd, Iain; Alkandry, Hicham

2011-05-01

149

Nonlinear optical generation of radiation near the frequency of the third harmonic of an iodine laser  

Microsoft Academic Search

Nonlinear optical generation of the third harmonic in the vapour of a metal at a frequency close to the tripled frequency of an iodine laser was achieved for the first time. Phase-matching conditions in the presence of a buffer gas and the nonlinear susceptibility were close to the calculated predictions. A change in the energy of the third harmonic pulses

A S Aleksandrovskii; V P Gerasimov; A K Popov; V V Slabko

1996-01-01

150

Application of a telescopic resonator to high-power chemical oxygen-iodine lasers  

Microsoft Academic Search

The application of an intraresonator telescope to high-power chemical oxygen-iodine lasers to decrease the output beam divergence is analyzed and demonstrated. A theoretical formula based on the ABCD matrix theory is developed to analyze the characteristics of the telescopic resonator. Calculations are carried out using Galilean type telescopes with magnification factors in the range of two to four, and our

Sanichiro Yoshida; Kouki Shimizu; Hari Tahil; Ikuzo Tanaka

1994-01-01

151

GAS AND VAPOR LASERS: Interferometric measurements of the atmospheric absorption of iodine laser radiation  

NASA Astrophysics Data System (ADS)

Interferometric measurements were made of the absorption of iodine laser radiation in air. It was found experimentally that the main contribution to the absorption comes from water vapor. The dependence of the absorption cross section for water molecules at ? = 1.315 ?m on the air pressure was determined. Its value at atmospheric pressure was found to be (6.8 + 0.8) 10- 25 cm2. The absorption coefficient measured in dry air was (8.0 + 3.5) 10- 8 cm- 1. The results were compared with calculations. A holographic method developed for analyzing the interferograms made it possible to measure interference fringe shifts of 1/100 of the fringe width or less and to observe the temporal and spatial evolution of a phase inhomogeneity.

Zuev, V. S.; Korol'kov, K. S.; Krylov, A. Yu; Nosach, O. Yu; Poskacheev, A. Yu

1988-10-01

152

Velocity Field Measurements in Rarefied, Hypersonic Flows of Nitrogen Using Laser-Induced Fluorescence of Iodine  

NASA Astrophysics Data System (ADS)

Velocity fields are measured in the shock layer and boundary layer on a plate with a cylindrical fin immersed in a hypersonic, free jet of nitrogen, using laser-induced fluorescence (LIF) of iodine. A sheet beam from a single-mode argon laser at 514 nm is used to excite hyperfine components of the P(13), R(15) and P(48), P(103) blended rotational-vibrational lines in the B-X electronic transition for iodine seeded in the flow. The Doppler broadening and shift of these lines, and the relative rotational line strengths are determined for excitation spectra recorded in a planar grid. Using this measurement technique, estimates for iodine of the mass velocity component and kinetic temperature of translation in the direction of laser propagation, rotational temperature, and relative number density are determined at each point. Sectional planes of the flow over the body are investigated at a spatial resolution on the scale of the molecular mean-free-path in the free jet near the plate leading edge. Two directions within each plane are examined, to determine the velocity vector and to investigate translational non-equilibrium. Predictions from two direct simulation Monte Carlo computations of the flow are compared with the measurements. Large values of slip velocity and temperature jump at the plate surface are observed for iodine. Measurements and DSMC predictions indicate strong translational non-equilibrium effects for the iodine in the shock wave and the thick boundary layer on the plate, and are qualitatively consistent with a bimodal velocity distribution function. As a consequence of the ratio of molecular masses, the translational non-equilibrium of iodine is much greater than for nitrogen.

Cecil, Eric

153

Iodine photodissociation laser SOFIA with MOPO-HF as a solid-state oscillator  

NASA Astrophysics Data System (ADS)

The hybrid iodine photodissociation laser SOFIA has been constructed. The pulse feeding the amplifier chain is the idler wave of an optical parametric oscillator (OPO) tuned to the atomic iodine transition at 1315 nm. This solid-state oscillator enables ps-synchronization to other laser systems. A homemade automatic stabilization of the OPO idler wave as to wavelength and pointing ensures long-term stable operation of the whole system. The active medium of the SOFIA amplifiers is a mixture of C3F7I and He. The SOFIA pulses are frequency-tripled in two KD*P crystals and then serve as the driver in a two-stage optical parametric amplification scheme in which chirped broadband Ti:sapphire laser pulses are amplified (OPCPA).

Dostl, J.; Tur?i?ov, H.; Krlikova, B.; Krl, L.; Huynh, J.

2009-11-01

154

Application of a telescopic resonator to high-power chemical oxygen-iodine lasers  

SciTech Connect

The application of an intraresonator telescope to high-power chemical oxygen-iodine lasers to decrease the output beam divergence is analyzed and demonstrated. A theoretical formula based on the ABCD matrix theory is developed to analyze the characteristics of the telescopic resonator. Calculations are carried out using Galilean type telescopes with magnification factors in the range of two to four, and the high-power chemical oxygen-iodine laser as an analysis model. By locating the telescope at a proper position on the optical axis, the overall telescopic resonator can be conveniently tailored to the hardware of this model laser in a way that the beam divergence and the resonator stability can be improved simultaneously. Experiments are carried out for one of the conditions used in the calculations. Measured divergence angles are in excellent agreement with the theoretical values.

Yoshida, Sanichiro; Shimizu, Kouki; Tahil, Hari; Tanaka, Ikuzo (Inst. of Research and Innovation, Chiba (Japan). Laser Lab.)

1994-01-01

155

Flow Measurements of Translational-Rotational Nonequilibrium Using Laser-Induced Iodine Fluorescence  

NASA Astrophysics Data System (ADS)

A shock wave impingement flow was studied under low temperature, low density conditions in a hypersonic free-jet wind tunnel. A sharp-edged flat plate was placed at zero incidence in the hypersonic core of a free-jet of nitrogen gas at Mach 12; a right circular cylinder mounted in the middle of the plate projected out normal to the plate surface. The oblique shock produced at the plate leading edge impinged on the detached bow shock wave produced by the cylinder. The symmetry plane in the flow was studied using a laser sheet-beam probe from a narrow-bandwidth laser source, which induced fluorescence in iodine molecules seeded in the gas. Fluorescence patterns produced by the sheet-beam were recorded by a charge-coupled device camera as the laser frequency was tuned in increments over a range spanning two distinct absorption lines in the iodine spectrum. The fluorescence intensity-versus-laser excitation frequency data recorded at each pixel was least-squares fitted to a nonequilibrium model of the iodine spectrum to estimate local translational and rotational temperature, velocity, and density. Contour plots of these results are presented at a resolution equal to roughly one mean-free-path of the oncoming flow at the plate leading edge. Profile plots of translational and rotational temperature on the plate are presented.

Cecil, Eric; McDaniel, James C.

2011-05-01

156

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

NASA Technical Reports Server (NTRS)

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

Seasholtz, Richard G.; Buggele, Alvin E

1997-01-01

157

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

SciTech Connect

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

Miley, G.H.

1992-03-01

158

Operational characteristics of high-pressure subsonic mode chemical oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

High-pressure subsonic mode operation of chemical oxygen- iodine laser (COIL) is studied. In this mode, the singlet oxygen generated by the liquid-jet singlet oxygen generator (SOG) is directly utilized in the optical cavity without supersonic expansion. Drastic reduction of the required vacuum pump capacity, and iodine consumption was obtained. We have demonstrated a 25.0 percent of chemical efficiency with a small-scale device. The scale-up version of the COIL is developed and initial tests are conducted. The device is so designed that it will operate for 2 hours at 1kW laser output. Due to the inadequate heat exchanger of basic hydrogen peroxide (BHP), performance of the system was not yet satisfactory. However, a 30-minute continuous operation o the counter-flow type jet SOG with recirculation of BHP was demonstrated for the first time.

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

2000-05-01

159

Use of basic deuterium peroxide in the chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

The chemical oxygen-iodine laser (COIL) uses a reaction of gaseous chorine and aqueous solution of basic oxygen peroxide (BHP) to produce oxygen singlet delta molecules, O2(1(Delta) ). Quenching of O2(1(Delta) ) during its extraction from the BHP solution and quenching of excited atomic iodine I* by water vapor from the O2(1(Delta) ) production process are well-known parasitic effects in COIL. This paper shows that both of these effects can be significantly reduced by replacing the hydrogen 1H1 isotope atoms in BHP by the 1H2 isotope atoms. In addition to restoring laser power lost to parasitic quenching, use of basic deuterium peroxide (BDP) rather than BHP is expected to allow generation of O2(1(Delta) ) at elevated temperature. This approach promises to save refrigerant, reduce the risk of BDP freezing, and delay precipitation of salt form BDP solution. Methods for producing BDP are outlined.

Vetrovec, John; Yang, Tientsai T.; Copeland, Drew A.

2000-05-01

160

A pared-down gas-phase kinetics for the chemical oxygen-iodine laser medium  

NASA Astrophysics Data System (ADS)

Kinetic data obtained in the last decade has resulted in revisions of some mechanisms of excitation and deactivation of excited states in the chemical oxygen-iodine laser (COIL) medium. This review considers new kinetic data and presents analyses of the mechanisms of pumping and quenching of electronically and vibrationally excited states in the oxygen-iodine laser media. An effective three-level model of I2 molecule excitation and relaxation has been developed. The calculated effective rate constants for deactivation of I2(X,11 ? ? ? 24) by O2, N2, He and CO2 are presented. A simplified kinetic package for the COIL active medium is recommended. This model consists of a 30-reaction set with 14 species. The results of calculations utilizing simplified model are in good agreement with the experimental data.

Pichugin, S. Yu.; Heaven, M. C.

2013-11-01

161

REVIEW: Excited states in the active media of oxygen iodine lasers  

NASA Astrophysics Data System (ADS)

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 O2 and I2 molecules are considered, and dissociation mechanisms of I2 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.

Azyazov, V. N.

2009-11-01

162

Theoretic and experimental studies on development of photodissociation laser pumped by solar light  

NASA Astrophysics Data System (ADS)

Being presented are the results of theoretical and experimental studies aimed at development of solar-pumped photo-dissociation laser fulfilled by RNTs "Applied Chemistry," Ioffe Physical Technical Institute and RFNC-VNIIEF. The model iodine laser concept was developed, and its parameters were calculated and experimentally optimized. The spectrum of xenon lamps was explored and its identical to solar spectrum features were demonstrated. The products of photolysis were studied in the active medium as well as the possibility of laser radiation conversion into the electrical one.

Andreev, Vladimir M.; Baboshin, V.; Eroshenko, V. A.; Fokanov, V. P.; Kargin, V. A.; Pavlov, A. B.; Shvartz, M.; Sobolev, Serge K.; Vinogradsky, Leonid M.

2004-06-01

163

PHYSICAL PROCESSES IN LASERS AND CONTROL OF LASER RADIATION PARAMETERS: Control of the duration of optical pulses from an oxygen-iodine chemical laser  

NASA Astrophysics Data System (ADS)

It is shown that long radiation pulses needed in applications of lasers in technology may be emitted efficiently by an oxygen-iodine chemical laser. Slow photolysis can increase the output pulse duration to approximately 1 ms while retaining a high efficiency. Calculations yield the dependence of the lasing characteristics on all the parameters of interest. It is demonstrated that at high active medium pressures (up to 100 Torr) and low iodine concentrations, the pulse duration may be regulated with a high specific output energy and a high photolysis efficiency.

Zagidullin, M. V.; Zaikin, A. P.; Igoshin, Valerii I.

1989-04-01

164

Active-medium inhomogeneities and optical quality of radiation of supersonic chemical oxygen-iodine lasers  

SciTech Connect

Optical inhomogeneities of the active medium of a supersonic chemical oxygen-iodine laser (COIL) and their effect on the radiation parameters are studied in the case when an unstable resonator is used. Classification of optical inhomogeneities and the main factors affecting the quality of COIL radiation are considered. The results of numerical simulation of a three-dimensional gas-dynamic active medium and an unstable optical resonator in the diffraction approximation are presented. The constraints in the fabrication of large-scale COILs associated with a deterioration of the optical quality of radiation are determined. (lasers)

Boreysho, A S; Druzhinin, S L; Lobachev, V V; Savin, A V; Strakhov, S Yu; Trilis, A V [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2007-09-30

165

Unstable resonators of high-power chemical oxygen-iodine lasers  

SciTech Connect

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)

Savin, A V; Strakhov, S Yu; Druzhinin, S L [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2006-09-30

166

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

NASA Astrophysics Data System (ADS)

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 ?. It is shown that the simplified two-level laser model satisfactorily predicts the output characteristics of OILs with a stable resonator at ?d <= 7. Efficient energy extraction from the OIL active medium is achieved in the case of ?d = 5 - 7, ? = 4 - 8.

Mezhenin, A. V.; Azyazov, V. N.

2012-12-01

167

GENETIC ALGORITHMS AND OPTIMIZING CHEMICAL OXYGEN-IODINE LASERS  

Microsoft Academic Search

This paper presents results from the first known application of the genetic algorithm (GA) technique for optimizing the performance of a laser system (chemical, solid-state, or gaseous). The effects of elitism, single point and uniform crossover, creep mutation, different random number seeds, population size, niching and the number of children per pair of parents on the performance of the GA

David L. Carroll

1996-01-01

168

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

169

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

NASA Astrophysics Data System (ADS)

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

Gao, Zhi; Hu, Limin; Shen, Yiqing

2004-05-01

170

Comparison of one- and three-dimensional computational fluid dynamics models of the supersonic chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A simple one-dimensional (1D) computational fluid dynamics (CFD) model of the chemical oxygen iodine laser (COIL) with supersonic mixing is compared with three-dimensional (3D) CFD models and with experimental measurements of the COIL parameters. Dependence of the gain, iodine dissociation fraction and temperature at the resonator optical axis and of the output lasing power on the iodine flow rate predicted by the 1D model is in good agreement with that found using 3D models and experimental results. Hence the 1D model can be used instead of much more complicated 3D models for estimates of the working parameters of supersonic COILs.

Brami-Rosilio, I.; Barmashenko, B. D.; Rosenwaks, S.

2012-09-01

171

DEVELOPMENT OF ADVANCED PHOTOLYTIC IODINE LASER (PIL) CUTTING AND JOINING TECHNOLOGIES FOR MANUFACTURING  

SciTech Connect

An evaluation was made of the Photolytic Iodine Laser (PIL) being developed by Advanced Optical Equipment and Services Corporation for metalworking applications. This laser operates in the infrared region of the spectrum and was anticipated to have a very small focal spot size and very low divergence. With these properties, it would be very effective at making small welds and narrow slots in metals. The program was of limited success due to low power output from the laser as well as power and positional instability. Some narrow slots were made and evaluated. The PIL may have applications in the electronics industry, even at low power, if the instability in the beam power and position can be solved.

MUSTALESKI, T.; RICHEY, M

1998-09-01

172

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

NASA Astrophysics Data System (ADS)

In an electric discharge oxygen-iodine laser, laser action at 1315 nm on the I(2P1/2)-->I(2P3/2) transition of atomic iodine is obtained by a near resonant energy transfer from O2(a 1?) which is produced using a low-pressure electric discharge. The discharge production of atomic oxygen, ozone, and other excited species adds higher levels of complexity to the postdischarge kinetics which are not encountered in a classic purely chemical O2(a 1?) generation system. Mixing effects are also present. In this paper we present postdischarge modeling results obtained using a modified version of the BLAZE-II gas laser code. A 28 species, 105 reaction chemical kinetic reaction set for the postdischarge kinetics is presented. Calculations were performed to ascertain the impact of a two stream mixing mechanism on the numerical model and to study gain as a function of reactant mass flow rates. The calculations were compared with experimental data. Agreement with experimental data was improved with the addition of new kinetics and the mixing mechanism.

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

2006-07-01

173

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

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

174

Comparing the efficiency of supersonic oxygen-iodine laser with different mixing designs  

NASA Astrophysics Data System (ADS)

The paper presents experimental studies of supersonic oxygen-iodine laser (OIL) using twisted-flow singlet oxygen generator (SOG) over a wide range of the singlet oxygen pressures and the buffer gas flow rates. The experiments used different designs of the nozzle unit and mixing system for singlet oxygen and iodine gas with the carrier gas (such as nitrogen or helium). For a wide range of the key parameters, the study looked at the efficiency of supersonic OIL with variation of the singlet oxygen pressure. The measurements were made for different positions of the iodine injection plane with respect to the critical cross-section (both in the subsonic part of the nozzle and in the supersonic flow). The gas pressure at the nozzle unit entry was varied from 50 to 250 Torr. The total pressure loss have been found for different mixing designs. Experimental curves are given for energy performance and chemical efficiency of the supersonic OIL as a function of the key parameters. Comparison is made between the calculated and experimental data. For the optimum conditions of OIL operation, chemical efficiency of 25-30% has been achieved.

Vyskubenko, Boris A.; Adamenkov, A. A.; Bakshin, V. V.; Efremov, V. I.; Ilyin, S. P.; Kolobyanin, Yu. V.; Krukovsky, I. M.; Kudryashov, E. A.; Moiseyev, V. B.

2003-12-01

175

Enhancement of the efficiency and control of emission parameters of an unstable-resonator chemical oxygen-iodine laser  

SciTech Connect

The outlook is considered for the development of a high-power supersonic flowing chemical oxygen-iodine laser operating as an amplifier and controlled by radiation from a master oscillator by using an unstable resonator with a hole-coupled mirror. The influence of the seed radiation intensity, the coupling-hole diameter, the active-medium length, and the magnification factor on the parameters of laser radiation is analysed. It is shown that the use of such resonators is most advisable in medium-power oxygen-iodine lasers for which classical unstable resonators are inefficient because of their low magnification factors. The use of unstable resonators with a hole-coupled mirror and injection provides the control of radiation parameters and a considerable increase in the output power and brightness of laser radiation. (control of laser radiation parameters)

Boreisho, A S; Lobachev, V V; Savin, A V; Strakhov, S Yu; Trilis, A V [Institute of Laser Instruments and Technologies, D F Ustinov 'VOENMEKh' Baltic State Technical University, St Petersburg (Russian Federation)

2007-07-31

176

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

NASA Astrophysics Data System (ADS)

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

palek, Otomar; Jirsek, Vt; ?ensk, Miroslav; Kodymov, Jarmila

2010-09-01

177

Centrifugal spray generator of singlet oxygen for a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

A centrifugal spray generator of singlet oxygen, O2(1?g), for driving a chemical oxygen-iodine laser was developed and its operation was experimentally studied. Modeling of the liquid separation from the gas flow showed that the separator designed could remove droplets larger than 0.5 ?m from gas, which is very important for the laser operation. This result was confirmed by experiments. Experimental studies proved that O2(1?g) could be produced with a high efficiency (chlorine utilization 0.68-0.87 and O2(1?g) yield 0.35-0.7) even at very high generator pressures (25-70 kPa), which cannot be attained by other O2(1?g) generators.

palek, O.; Hrub, J.; ?ensk, M.; Jirsek, V.; Kodymov, J.

2010-09-01

178

Removal of Water Vapor in a Mist Singlet Oxygen Generator for Chemical Oxygen Iodine Laser  

NASA Astrophysics Data System (ADS)

The mist singlet oxygen generator (Mist-SOG) for a chemical oxygen iodine laser (COIL) has been developed in order to increase basic hydrogen peroxide (BHP) utilization. It was clarified that the Mist-SOG generated much more water vapor than conventional SOGs because the heat capacity of BHP is small. The water vapor deactivates the excited iodine and depresses the laser power. Therefore, a jet-cold trap was developed in order to remove the water vapor while maintaining a minimum deactivation of singlet oxygen. In this method, a nozzle was used to spray chilled H2O2 at 238 K as a thin layer directly to the gas flow to achieve a large specific surface area for water vapor. As a result, the water vapor mole fraction was reduced to 7% from 18% with the BHP utilization of 21% at the Cl2 consumption rate of 3.5 mmol/s (Cl2 input flow rate of 8.0 mmol/s) for 65-?m-diameter BHP droplets.

Muto, Shigeki; Endo, Masamori; Nanri, Kenzo; Fujioka, Tomoo

2004-02-01

179

Singlet oxygen generator for a solar powered chemically pumped iodine laser  

NASA Technical Reports Server (NTRS)

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

Busch, G. E.

1984-01-01

180

BRIEF COMMUNICATIONS: Relative stability of working mixtures of iodine photodissociation lasers in the presence of stimulated enthalpy scattering  

Microsoft Academic Search

A flashlamp-pumped iodine laser was investigated and it was found that the ratios of the experimentally measured depths of dips in the profiles of inhomogeneity waves in various working mixtures were equal to the ratios of the transient values of the gain in the case of the theoretically calculated stimulated enthalpy scattering. These observations were used as the basis of

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

1985-01-01

181

NONLINEAR OPTICAL PHENOMENA: Nonlinear optical generation of radiation near the frequency of the third harmonic of an iodine laser  

Microsoft Academic Search

Nonlinear optical generation of the third harmonic in the vapour of a metal at a frequency close to the tripled frequency of an iodine laser was achieved for the first time. Phase-matching conditions in the presence of a buffer gas and the nonlinear susceptibility were close to the calculated predictions. A change in the energy of the third harmonic pulses

A. S. Aleksandrovskii; V. P. Gerasimov; A. K. Popov; V. V. Slabko

1996-01-01

182

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

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

183

BRIEF COMMUNICATIONS: Regeneration of the active mixture of an iodine laser pumped by radiation from an open discharge  

Microsoft Academic Search

A chromatographic mass-spectroscopic analysis was made of the spent mixture in an iodine laser and amplifier pumped by an open high-current discharge. It was found that the chemical processes differed for the driven regime (amplifier) and the free-lasing regime (laser). This difference should result in the production of a larger quantity of I2 in the driven regime which may give

L. K. Gavrilina; V. S. Zuev; V. A. Katulin; N. N. Korzhavina; Yu S. Leonov; Yu I. Morozov; A. L. Petrov

1982-01-01

184

Sub-Doppler spectroscopy of molecular iodine around 541 nm with a novel solid state laser source  

Microsoft Academic Search

We report high resolution sub-Doppler spectroscopy of molecular iodine hyperfine transitions around 541 nm. A novel solid state source, based on a diode laser, a Yb+ fiber amplifier and a periodically-poled KTiOPO4 crystal, was developed, having a continuous tunability range of 1.2 THz. The performance of this crystal for doubling 1083 nm laser radiation is demonstrated for the first time,

P. Cancio Pastor; P. Zeppini; A. Arie; P. De Natale; G. Giusfredi; G. Rosenman; M. Inguscio

2000-01-01

185

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

NASA Technical Reports Server (NTRS)

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

Walker, Gilbert H.; Heinbockel, John H.

1987-01-01

186

Oxygen atom density and thermal energy control in an electric-oxygen iodine laser  

NASA Astrophysics Data System (ADS)

Experiments[1] with Electric Oxygen-Iodine Laser (ElectricOIL) heat exchanger technology have demonstrated improved control of oxygen atom density and thermal energy, with minimal quenching of O2(a1?), and increasing small signal gain from 0.26% cm-1 to 0.30% cm-1. Heat exchanger technological improvements were achieved through both experimental and modeling studies, including estimation of O2(a1?) surface quenching coefficients for select ElectricOIL materials downstream of a radio-frequency discharge-driven singlet oxygen generator. Estimation of O2(a1?) quenching coefficients is differentiated from previous studies by inclusion of oxygen atoms, historically scrubbed using HgO[2-4] or AgO[5]. High-fidelity, time-dependent and steady-state simulations are presented using the new BLAZE-VI multi-physics simulation suite[6] and compared to data.

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

2014-02-01

187

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

188

Regeneration of basic hydrogen peroxide for chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Regeneration of Basic Hydrogen Peroxide (BHP) for Chemical Oxygen Iodine Laser (COIL) has been studied. The apparatus is an electrolyte H2O2 generator, which is composed of anode chamber, cathode chamber with gas diffusion electrode and cation exchange membrane. BHP containing 5 to 10 weight percent (wt%) of H2O2 is supplied to the apparatus and the change in the H2O2 concentration is measured for various operational conditions. A 5.11wt% BHP is regenerated with current efficiency of 92% and a 10.4wt% BHP is regenerated with current efficiency of 73%. It is found that the BHP flow rate and temperature of the BHP are critical to obtain high current efficiency.

Hano, Masami; Wakita, Syuhei; Uno, Masaharu; Endo, Masamori; Nanri, Kenzo; Takeda, Shuzaburo; Fujioka, Tomoo

2003-11-01

189

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

NASA Astrophysics Data System (ADS)

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

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

2003-08-01

190

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

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

191

Lasing in supersonic chemical oxygen-iodine lasers: recent modeling and comparison with experiment  

NASA Astrophysics Data System (ADS)

Simple models are developed, describing the power extraction in chemical oxygen-iodine lasers (COILs) with stable and unstable resonators. For stable resonators the model is applied to the ejector high pressure COIL and the results are compared with the experimental data (see also a preceding paper by Rosenwaks et al.). The positive and negative branch unstable resonators with cylindrical mirrors that have been recently used in COILs are studied theoretically using a geometrical optics model. The optical extraction efficiency, spatial distributions of the intracavity radiation intensity in the flow direction and the intensity in the far field are calculated for both kinds of resonators as a function of both the resonator and COIL parameters. The optimal resonator magnifications corresponding to the maximum intensity in the far field are found.

Barmashenko, Boris D.; Waichman, Karol; Rosenwaks, Salman

2010-09-01

192

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

NASA Astrophysics Data System (ADS)

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.

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

2000-01-01

193

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

SciTech Connect

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

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

2010-12-29

194

CONTROL OF LASER RADIATION PARAMETERS: Enhancement of the efficiency and control of emission parameters of an unstable-resonator chemical oxygeniodine laser  

NASA Astrophysics Data System (ADS)

The outlook is considered for the development of a high-power supersonic flowing chemical oxygeniodine laser operating as an amplifier and controlled by radiation from a master oscillator by using an unstable resonator with a hole-coupled mirror. The influence of the seed radiation intensity, the coupling-hole diameter, the active-medium length, and the magnification factor on the parameters of laser radiation is analysed. It is shown that the use of such resonators is most advisable in medium-power oxygeniodine lasers for which classical unstable resonators are inefficient because of their low magnification factors. The use of unstable resonators with a hole-coupled mirror and injection provides the control of radiation parameters and a considerable increase in the output power and brightness of laser radiation.

Boreisho, A. S.; Lobachev, V. V.; Savin, A. V.; Strakhov, S. Yu; Trilis, A. V.

2007-07-01

195

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

PubMed

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?gg(-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 110kDa, 40kDa, 27kDa, 20kDa and 10kDa. 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

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

2014-09-01

196

Multiphase reacting flow modeling of singlet oxygen generators for chemical oxygen iodine lasers.  

SciTech Connect

Singlet oxygen generators are multiphase flow chemical reactors used to generate energetic oxygen to be used as a fuel for chemical oxygen iodine lasers. In this paper, a theoretical model of the generator is presented along with its solutions over ranges of parameter space and oxygen maximizing optimizations. The singlet oxygen generator (SOG) is a low-pressure, multiphase flow chemical reactor that is used to produce molecular oxygen in an electronically excited state, i.e. singlet delta oxygen. The primary product of the reactor, the energetic oxygen, is used in a stage immediately succeeding the SOG to dissociate and energize iodine. The gas mixture including the iodine is accelerated to a supersonic speed and lased. Thus the SOG is the fuel generator for the chemical oxygen iodine laser (COIL). The COIL has important application for both military purposes--it was developed by the US Air Force in the 1970s--and, as the infrared beam is readily absorbed by metals, industrial cutting and drilling. The SOG appears in various configurations, but the one in focus here is a crossflow droplet generator SOG. A gas consisting of molecular chlorine and a diluent, usually helium, is pumped through a roughly rectangular channel. An aqueous solution of hydrogen peroxide and potassium hydroxide is pumped through small holes into the channel and perpendicular to the direction of the gas flow. So doing causes the solution to become aerosolized. Dissociation of the potassium hydroxide draws a proton from the hydrogen peroxide generating an HO{sub 2} radical in the liquid. Chlorine diffuses into the liquid and reacts with the HO{sub 2} ion producing the singlet delta oxygen; some of the oxygen diffuses back into the gas phase. The focus of this work is to generate a predictive multiphase flow model of the SOG in order to optimize its design. The equations solved are the so-called Eulerian-Eulerian form of the multiphase flow Navier-Stokes equations wherein one set of the equations represents the gas phase and another equation set of size m represents the liquid phase. In this case, m is representative of the division of the liquid phase into distinct representations of the various droplet sizes distributed in the reactor. A stabilized Galerkin formulation is used to solve the equation set on a computer. The set of equations is large. There are five equations representing the gas phase: continuity, vector momentum, heat. There are 5m representing the liquid phase: number density, vector momentum, heat. Four mass transfer equations represent the gas phase constituents and there are m advection diffusion equations representing the HO{sub 2} ion concentration in the liquid phase. Thus we are taking advantage of and developing algorithms to harness the power of large parallel computing architectures to solve the steady-state form of these equations numerous times so as to explore the large parameter space of the equations via continuation methods and to maximize the generation of singlet delta oxygen via optimization methods. Presented here will be the set of equations that are solved and the methods we are using to solve them. Solutions of the equations will be presented along with solution paths representing varying aerosol loading-the ratio of liquid to gas mass flow rates-and simple optimizations centered around maximizing the oxygen production and minimizing the amount of entrained liquid in the gas exit stream. Gas-entrained liquid is important to minimize as it can destroy the lenses and mirrors present in the lasing cavity.

Salinger, Andrew Gerhard; Pawlowski, Roger Patrick; Hewett, Kevin B. (Air Force Research Laboratory, Albuquerque, NM); Madden, Timothy J. (Air Force Research Laboratory, Albuquerque, NM); Musson, Lawrence Cale

2008-08-01

197

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

SciTech Connect

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.

Lambert, Joseph G. [Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104 (United States); Hernandez-Diaz, Carlos; Williamson, J. Charles [Department of Chemistry, Willamette University, Salem, Oregon 97301 (United States)

2010-01-15

198

Parametric studies of a small-scale chemical oxygen-iodine laser/jet generator system: recent achievements  

NASA Astrophysics Data System (ADS)

Recent results of parametric studies of an efficient supersonic chemical oxygen-iodine laser are presented. The laser is energized by a jet type singlet oxygen generator, operated without primary buffer gas and applies simple nozzle geometry and transonic mixing of iodine and oxygen. Output power of 190 W with chemical efficiency of 18% was obtained in a 5 cm gain length for Cl2 flow rate of 11.8 mmole/s. The power is studied as a function of the distance between the optical axis and the supersonic nozzle exit plane, the molar flow rates of various reagents, the BHP and gas pressures in the generator, the type of the secondary buffer gas (N2 or He) and the stagnation temperature of the gas. It is found that the power under the present operation conditions is almost unaffected by water vapor in the medium. The role of buffer gas under different conditions is discussed.

Furman, Dov; Barmashenko, Boris D.; Rosenwaks, Salman

1998-05-01

199

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

NASA Astrophysics Data System (ADS)

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.

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

2003-12-01

200

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

NASA Astrophysics Data System (ADS)

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

Novk, O.; Tur?i?ov, H.; Smr, M.; Huynh, J.; Pfeifer, M.; Straka, P.

2012-09-01

201

Cavity-enhanced absorption: detection of nitrogen dioxide and iodine monoxide using a violet laser diode  

NASA Astrophysics Data System (ADS)

We present an application of cavity-enhanced absorption spectroscopy with an off-axis alignment of the cavity formed by two spherical mirrors and with time integration of the cavity-output intensity for detection of nitrogen dioxide (NO2) and iodine monoxide (IO) radicals using a violet laser diode at ?=404.278 nm. A noise-equivalent (1?? root-mean-square variation of the signal) fractional absorption for one optical pass of 4.510-8 was demonstrated with a mirror reflectivity of 0.99925, a cavity length of 0.22 m and a lock-in-amplifier time constant of 3 s. Noise-equivalent detection sensitivities towards nitrogen dioxide of 1.81010 molecule cm-3 and towards the IO radical of 3.3109 molecule cm-3 were achieved in flow tubes with an inner diameter of 4 cm for a lock-in-amplifier time constant of 3 s. Alkyl peroxy radicals were detected using chemical titration with excess nitric oxide (RO2+NO-->RO+NO2). Measurement of oxygen-atom concentrations was accomplished by determining the depletion of NO2 in the reaction NO2+O-->NO+O2. Noise-equivalent concentrations of alkyl peroxy radicals and oxygen atoms were 31010 molecule cm-3 in the discharge-flow-tube experiments.

Kasyutich, V. L.; Bale, C. S. E.; Canosa-Mas, C. E.; Pfrang, C.; Vaughan, S.; Wayne, R. P.

202

Singlet oxygen generation in gas discharge for oxygen-iodine laser pumping  

NASA Astrophysics Data System (ADS)

The possibility of development of effective discharged singlet oxygen (SO) generator (DSOG) for oxygen-iodine laser (OIL) is studied in detail. Researches of kinetics of oxygen atoms and oxygen molecules in the lowest metastable singlet states have been carried out in the different discharges and its afterglow (DC discharges, E-beam controlled discharge and RF discharges) in both CW and pulsed mode in a wide range of conditions (pressures, gas mixtures, energy deposits etc.). The models developed for all the discharges have allowed us to analyze SO generation and loss mechanisms and to find out the key-parameters controlling the highest SO yield. It is shown that in addition to spatial plasma uniformity at low E/N and high specific energy deposit per oxygen molecule, DSOG must be oxygen atom free to avoid fast three-body quenching of SO by atomic oxygen with increasing pressure and thereby to provide pressure scaling (in tens Torrs) for applying to real OIL systems.

Lopaev, D. V.; Braginsky, O. V.; Klopovsky, K. S.; Kovalev, A. S.; Mankelevich, Yu. A.; Popov, N. A.; Rakhimov, A. T.; Rakhimova, T. V.; Vasilieva, A. N.

2004-09-01

203

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

NASA Astrophysics Data System (ADS)

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

Jirsek, V.; Hrub, J.; palek, O.; ?ensk, M.; Kodymov, J.

2010-09-01

204

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

205

Strong-field ionization of molecular iodine traced with XUV pulses from a free-electron laser  

NASA Astrophysics Data System (ADS)

Ultrafast dynamics of a molecular wave packet created by a strong 120-fs near-infrared (800 nm) laser pulse in iodine has been probed by synchronized 13.4-nm, 35-fs extreme-ultraviolet pulses delivered by the free-electron laser facility in Hamburg, FLASH. The kinetic energy release of the multiply charged ionic fragments reveals three essential steps of strong-field-induced molecular fragmentation dynamics: (i) The creation of I22+ and (I22+)* molecular ions proceeds within (75 15) fs full-width-at-half-maximum. (ii) With the onset of the I22+ fragmentation the probability to lose a further electron within the same optical laser pulse rises with increasing I+I+ internuclear separation and reaches its maximum after 30 fs with respect to the pulse maximum. (iii) Charge separation into the I22+?I2++I dissociative channel with an asymmetric charge distribution is completed after (121 22) fs.

Krikunova, Maria; Maltezopoulos, Theophilos; Wessels, Philipp; Schlie, Moritz; Azima, Armin; Gaumnitz, Thomas; Gebert, Thomas; Wieland, Marek; Drescher, Markus

2012-10-01

206

Quantitative measurement of transverse injector and free stream interaction in a nonreacting SCRAMJET combustor using laser-induced iodine fluorescence  

NASA Technical Reports Server (NTRS)

A preliminary quantitative study of the compressible flowfield in a steady, nonreacting model SCRAMJET combustor using laser-induced iodine fluorescence (LIIF) is reported. Measurements of density, temperature, and velocity were conducted with the calibrated, nonintrusive, optical technique for two different combustor operating conditions. First, measurements were made in the supersonic flow over a rearward-facing step without transverse injection for comparison with calculated pressure profiles. The second configuration was staged injection behind the rearward-facing step at an injection dynamic pressure ratio of 1.06. These experimental results will be used to validate computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields.

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

1987-01-01

207

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

208

A simplified analytic model for gain saturation and power extraction in the flowing chemical oxygen-iodine laser  

SciTech Connect

This paper describes the development of a simplified saturation model (SSM) for predicting power extraction from a chemical oxygen-iodine laser (COIL). Using the Fabry-Perot gain saturation assumption, analytic expressions for COIL extraction efficiency are presented for both constant-density and variable-density cavity conditions. The model treats mirror scattering, nonsaturable distributed losses, and diffractive losses from the mode-limiting aperture and is shown to be in excellent agreement with experimental COIL power extraction data. A comparison of the model with the Rigrod power extraction model is presented showing that the Rigrod model accurately predicts COIL extraction efficiency only in the limit that the COIL device no longer behaves as a transfer laser.

Hager, G.D.; Helms, C.A.; Truesdell, K.A. [Phillips Lab., Kirtland AFB, NM (United States)] [Phillips Lab., Kirtland AFB, NM (United States); Plummer, D.; Erkkila, J.; Crowell, P. [Logicon RDA, Albuquerque, NM (United States)] [Logicon RDA, Albuquerque, NM (United States)

1996-09-01

209

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

SciTech Connect

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.

Chukalovsky, A. A.; Rakhimova, T. V.; Klopovsky, K. S.; Mankelevich, Yu. A.; Proshina, O. V. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2011-03-15

210

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, ...

211

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

NASA Technical Reports Server (NTRS)

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

1982-01-01

212

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

PubMed

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

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

2007-07-26

213

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  

Microsoft Academic Search

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

Lavern A. Schlie; Robert D. Rathge

1992-01-01

214

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

Microsoft Academic Search

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

Zongmin Hu; Zonglin Jiang; Rhoshin Myong; Taehwan Cho

2008-01-01

215

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

216

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

NASA Astrophysics Data System (ADS)

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

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

2011-02-01

217

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

SciTech Connect

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

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

2012-09-30

218

Simulation and optimization of hybrid wind-solar-pumped-storage power system  

Microsoft Academic Search

wind-solar-pumped-storage power system is brought forward, which is based on traditional hybrid wind-solar power system, and which storages energy by using pumped-storage. The mathematical models of main components of the system are brought forward. The optimization method is by using improved heredity arithmetic. Aim to the island the system model is brought forward, an d the optimization method is applied,

Ren Yan; Li Yanpin

2011-01-01

219

Buffer gas mixing with active gas on chemical oxygen-iodine laser performance with jet type SOG  

NASA Astrophysics Data System (ADS)

The increasing of stagnation pressure and Re number of gas flow is a very important for supersonic oxygen-iodine laser (COIL). This goal can be achieved with the aid of high pressure singlet oxygen generator (SOG) and high dilution of oxygen with buffer gas of high molecular weight downstream of SOG. The study of COIL operated with jet type SOG at 10 and 20 mmole/s of chlorine flow rate and 50 torr output of pure oxygen is presented. Two experimental set-up were tested. In the first one the mixing of chlorine with buffer gas was provided upstream of SOG gas inlet. In the second one the pure chlorine was injected into SOG and oxygen was mixed with buffer gas downstream of SOG outlet. The stability of jet SOG in the first set-up strongly depended on partial buffer gas pressure and its molecular weight: at higher pressures and molecular weight the stability of SOG operation was worse. In the second set-up the operation of SOG didn't depend on buffer gas pressure and its molecular weight. COIL output power was highest for first set-up with dilution of chlorine by buffer gas until SOG stable operated. In the second set-up the output power was in twice less and strongly depend on type and position of buffer gas injector between SOG and iodine injector. This dependence strongly demonstrated the importance of gas mixing to molecular level for achieving highest COIL power. Another problem considered in this work is connected with BHP heating that important for recirculation of liquid in long time duration COIL operating system. The correlation of BHP heating and O2(1(Delta) ) yield is presented. It is shown that nacsent O2(1(Delta) ) yield is close to 100%.

Zagidullin, Marsel V.; Nikolaev, Valeri D.; Svistun, Michael I.; Safonov, Vladimir S.; Ufimtsev, Nikolay I.

1996-03-01

220

Development of a mist singlet oxygen generator for a chemical oxygen-iodine laser  

NASA Astrophysics Data System (ADS)

Mist singlet oxygen generator (Mist-SOG) has been developed in order to increase the BHP utilization. On the other hand, Mist-SOG generates much more water vapor than conventional SOG because the heat capacity of the BHP is small. It is well known that the water vapor deactivates the excited iodine. In order to remove the water vapor, we developed a jet-cold trap. In this method, a nozzle sprayed a chilled H2O2 at 238K with a thin layer form to the gas flow directly in order to get the large specific surface for the water vapor. As a result of experiment, Water vapor partial pressure reduced from 3.3 Torr at the BHP flow rate of 2.2 ml/s and Cl2 flow rate of 3.5 mmol/s for the 65?m BHP droplets.

Muto, Shigeki; Endo, Masamori; Nanri, Kenzo; Fujioka, Tomoo

2003-11-01

221

Iodine monofluoride 140kW laser: small signal gain and operating parameters  

Microsoft Academic Search

Output energies in excess of 4 mJ in a approx.30-nsec FWHM pulse (approx.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

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

1981-01-01

222

Iodine monofluoride 140-kW laser: small signal gain and operating parameters  

SciTech Connect

Output energies in excess of 4 mJ in a approx.30-nsec FWHM pulse (approx.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 +- 0.7)%-cm/sup -1/ and approx.0.3%-cm/sup -1/, respectively.

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

1981-02-01

223

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

SciTech Connect

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

Berg, M.A.

1985-09-01

224

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

NASA Astrophysics Data System (ADS)

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

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

2012-02-01

225

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

226

Numerical study on the performance of nozzle flow for supersonic chemical oxygeniodine lasers  

Microsoft Academic Search

Laser performance is greatly dependent on its operating conditions due to the strong coupling among multi-physics such as\\u000a gas-dynamics, chemical reaction kinetics and optics in the mixing nozzle of COIL. In this paper, 3D CFD technology is used\\u000a to simulate the mixing and reactive flow of subsonic cross jet scheme at different conditions. Results obtained show that\\u000a the jet penetration

Zongmin Hu; Junming L; Zonglin Jiang; Rho-Shin Myong; Tae-Hwan Cho

2008-01-01

227

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)

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.

Kirschbaum, C.

1988-01-01

228

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

NASA Astrophysics Data System (ADS)

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

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

2010-02-01

229

Numerical study on the performance of nozzle flow for supersonic chemical oxygen-iodine lasers  

NASA Astrophysics Data System (ADS)

Laser performance is greatly dependent on its operating conditions due to the strong coupling among multi-physics such as gas-dynamics, chemical reaction kinetics and optics in the mixing nozzle of COIL. In this paper, 3D CFD technology is used to simulate the mixing and reactive flow of subsonic cross jet scheme at different conditions. Results obtained show that the jet penetration depth plays a dominant role in the spatial distribution of small signal gains. In the case of over-penetration, unsteady flow structures are induced by impinging between the opposing jets. The optimum spatial distribution of the chemical performance cannot be obtained even if the full penetration condition is achieved through the subsonic transverse jet mixing scheme in the COIL nozzle flow.

Hu, Zongmin; L, Junming; Jiang, Zonglin; Myong, Rho-Shin; Cho, Tae-Hwan

2008-04-01

230

Planar Laser-Induced Iodine Fluorescence Measurements in Rarefied Hypersonic Flow  

NASA Technical Reports Server (NTRS)

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

Cecil, Eric; McDaniel, James C.

2005-01-01

231

Design investigation of solar powered lasers for space applications  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

232

In-situ measurements of iodine monoxide at coastal and open-ocean locations using laser induced fluorescence spectroscopy  

NASA Astrophysics Data System (ADS)

The halogen oxides, IO and BrO, have traditionally been measured using the Long Path-Differential Optical Absorption Spectroscopy (LP-DOAS) technique. Laser Induced Fluorescence (LIF), however, provides a sensitive and selective alternative method to detect IO. LIF provides a point-source measurement of IO; comparison of IO data taken using LIF and LP-DOAS can help determine local sources of iodine at coastal sites. In-situ techniques, such as LIF, also allow a direct comparison with other co-located in-situ instruments, improving the understanding of the chemical interactions that occur. Furthermore the size, weight and flexibility of such instruments mean that they are readily deployable on ship and aircraft platforms, as well as at ground-based sites. The University of Leeds LIF-IO instruments have been operational since 2006; data taken at three contrasting locations will be presented. IO measurements were made at the Mace Head Observatory on the west coast of Ireland in 2007. The site is predominantly impacted by background air-masses from the north Atlantic. An anti-correlation between IO concentration and tidal height during the day was observable; a maximum of 33 pptV was observed during the lowest tides. A comparison with concurrent LP-DOAS measurements demonstrates local hot-spots of IO production. The release of I2 from a narrow strip of macro-algae, specifically laminaria, along this coastline acts as the major iodine source. In-situ IO measurements were also made at a second coastal site, in Roscoff, France as part of the Reactive Halogens in the Marine Boundary Layer (RHaMBLe) project. This stretch of coastline is also impacted by macro-algae and high concentrations of IO were again observable at low-tide. In contrast to Mace Head, the Roscoff site was influenced by local pollution. A negative correlation between IO and NO2 was observed during low-tide periods; a positive correlation between IO and new particle bursts was also recorded. This work demonstrates the influence of the halogen chemistry upon local air quality and climate. As part of the second leg of the RHaMBLe project a cruise took place on-board the RV Discovery in the tropical marine boundary layer. IO measurements were made close to the Canary Islands. Simultaneous measurements of IO (and BrO) were made from the Cape Verde Islands using LP-DOAS, along with measurements of OH and HO2 made using Fluorescence Assay by Gas Expansion (FAGE). Although present at much lower concentrations in the open-ocean (IO = 1.4 pptV, BrO = 2.5 pptV), the halogen oxides were found to increase the OH concentration (the dominant tropospheric oxidiser) by up to 12 % and consequently reduce the CH4 lifetime (an important greenhouse gas) by a corresponding 12 % in this region. This finding has significant implications for global models that currently exclude halogen chemistry.

Commane, R.; Whalley, L. K.; Furneaux, K. L.; Ingham, T.; Bloss, W. J.; Heard, D. E.

2008-12-01

233

Solar-Powered Laser Communications System for Space.  

National Technical Information Service (NTIS)

Space communications with the Nd:YAG laser offers extended operating life due to the use of direct solar pumping of the laser. Solar radiation is converted directly to laser light. A laser communications system now in final development will allow the tran...

J. D. Barry

1977-01-01

234

Optical characterization of Er-doped glasses for solar-pumped laser applications  

NASA Astrophysics Data System (ADS)

Quantum efficiencies of Er3+-doped silicate, phosphate, tellurite and fluoride glasses have been examined under simulated sunlight excitation. The quantum efficiency of the whole emission bands was obtained as about 75 % for fluoride glass and about 2 % for silicate glass. The maximum quantum efficiency of the emission band at 1530 nm was about 35 % for fluoride glass and about 17 % for silicate glass. The product of the stimulated emission cross-section and the emission lifetime ?st?f was about 4610-24 cm2 sec for fluoride glass and about 5410-24 cm for silicate glass. These values are about 2-4 times larger than that of Nd-doped glasses.

Suzuki, Takenobu; Iwata, Yasuyuki; Nogata, Kohei; Mizuno, Shintaro; Ito, Hiroshi; Hasegawa, Kazuo; Ohishi, Yasutake

2013-03-01

235

Tracing iodine  

NASA Astrophysics Data System (ADS)

Pierangelo Metrangolo and Giuseppe Resnati celebrate the bicentenary of the discovery of iodine - a good time to also bring to its conclusion an international project that aims to define and categorize halogen bonding.

Metrangolo, Pierangelo; Resnati, Giuseppe

2011-03-01

236

Iodine and Pregnancy  

MedlinePLUS

... or visit us online at: www.OTISpregnancy.org . Iodine and Pregnancy This sheet talks about iodine during ... advice from your health care provider. What is iodine? Iodine is a naturally occurring element that our ...

237

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

PubMed

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

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

238

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

NASA Astrophysics Data System (ADS)

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 A2?3/2 (v' = 2) ? X2?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.

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

239

Experimental research on a new solar pump-free lithium bromide absorption refrigeration system with a second generator  

Microsoft Academic Search

This paper is concerned with experimental research on a new solar pump-free lithium bromide absorption refrigeration system with a second generator. By using the second generator together with a lunate thermosiphon elevation tube, the required minimum driving temperature of the heat source is only 68C compared to above 100C in traditional absorption refrigeration systems. Based on the horizontal-tube falling-film method,

Gu Yaxiu; Wu Yuyuan; Ke Xin

2008-01-01

240

Iodine Investigators!  

NSDL National Science Digital Library

In this activity on page 7 of the PDF, learners use iodine to identify foods that contain starch. Compare the starch content of a ripe banana, an overripe banana, milk, and flour mixed with water. Use this experiment to introduce learners to starch and how our bodies use starch to break down nutrients during digestion. Safety notes: DO NOT eat any tested foods or the iodine. Wear goggles. Follow the safety tips on the bottom of page 7 as well as Milli's safety tips on page 5.

Society, American C.

2009-01-01

241

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

242

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

Microsoft Academic Search

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

P. G. Kryukov

1995-01-01

243

Blackbody-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping. Previously announced in STAR as N83-10420

Christiansen, W. H.; Insuik, R. J.

1983-07-01

244

Enabling lunar and space missions by laser power transmission  

Microsoft Academic Search

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

R. J. De Young; J. E. Nealy; D. H. Humes; W. E. Meador

1992-01-01

245

Iodine and thyroid function  

PubMed Central

Severe iodine deficiency causes hypothyroidism that results in impaired somatic growth and motor development in children. Mild and moderate iodine deficiencies cause multifocal autonomous growth of thyroid, which results in thyrotoxicosis. On the other hand, iodine excess is associated with the development of hypothyroidism and thyroid autoimmunity. In areas of iodine deficiency, a sudden increase in iodine intake is associated with transient hyperthyroidism. Recent studies demonstrated that long-term thyroid function of subjects who experienced both iodine deficiency and iodine excess during childhood tended to be abnormal despite optimization of their current iodine intake. Iodine status in the Korean Peninsula is very unique because people in the Republic of Korea have been shown to have predominantly excessive iodine levels, whereas the Democratic People's Republic of Korea is known to be an iodine-deficient area. Further research is warranted to verify the optimal ranges of iodine intake and to clarify the effects of iodine intake on thyroid disorders in the Korean Peninsula.

2014-01-01

246

Iodination of phenol.  

National Technical Information Service (NTIS)

Phenol is iodinated in aqueous solution at pH 5 (acetate buffer) by elemental iodine or, if the iodine is present as iodide, enzymatically controlled by peroxidases. Generally mono-, di- and triiodophenols are obtained, the overall product composition bei...

J. V. Christiansen A. Feldthus L. Carlsen

1990-01-01

247

Hair iodine for human iodine status assessment.  

PubMed

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 0.1-0.15??g/g. Then there was a saturation range interval of about 0.1-2.0??g/g where the deposition of iodine in the hair was linearly increasing (R(2)=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 0.565-0.739??g/g (55-65%). PMID:24446669

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

2014-06-01

248

An Electronic Transition Chemical Laser.  

National Technical Information Service (NTIS)

This report covers unclassified laser research performed at the Air Force Weapons Laboratory. The two reports included herein describe the first operation of an oxygen-iodine chemical laser and the first transverse flow high efficiency oxygen-iodine chemi...

W. E. McDermott N. R. Pchelkin D. J. Bernard R. R. Bousek

1978-01-01

249

A blackbody radiation-pumped CO2 laser experiment  

NASA Astrophysics Data System (ADS)

Thermal radiation from a high temperature oven was used as an optical pump to achieve lasing from CO2 mixtures. Laser output as a function of blackbody temperature and gas conditions is described. This achievement represents the first blackbody cavity pumped laser and has potential for solar pumping.

Christiansen, W. H.; Insuik, R. J.; Deyoung, R. J.

1982-09-01

250

Enabling Lunar and Space Missions by Laser Power Transmission.  

National Technical Information Service (NTIS)

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...

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

1992-01-01

251

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

SciTech Connect

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.

Kostyukevich, Yu I; Umanskii, Stanislav Ya [N N Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow (Russian Federation)

2011-12-31

252

Iodine and Pregnancy  

PubMed Central

Iodine is a necessary element for the production of thyroid hormone. We will review the impact of dietary iodine status on thyroid function in pregnancy. We will discuss iodine metabolism, homeostasis, and nutritional recommendations for pregnancy. We will also discuss the possible effects of environmental contaminants on iodine utilization in pregnant women.

Yarrington, Christina; Pearce, Elizabeth N.

2011-01-01

253

Laser welding in space  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

254

Laser ablation and 131-iodine: a 24-month pilot study of combined treatment for large toxic nodular goiter.  

PubMed

Context: It is normally recognized that the preferred treatment in large toxic thyroid nodules should be thyroidectomy. Objective: The aim of the study was to assess the efficacy of combined laser ablation treatment (LAT) and radioiodine 131 (131I) treatment of large thyroid toxic nodules with respect to rapidity of control of local symptoms, of hyperthyroidism, and of reduction of administered 131I activity in patients at refusal or with contraindications to surgery. Design and Setting: We conducted a pilot study at a single center specializing in thyroid care. Patients: Fifteen patients were treated with LAT, followed by 131I (group A), and a series of matched consecutive patients were treated by 131I only (group B). Intervention(s): Laser energy was delivered with an output power of 3 W (1800 J per fiber per treatment) through two 75-mm, 21-gauge spinal needles. Radioiodine activity was calculated to deliver 200 Gy to the hyperfunctioning nodule. Main Outcome Measure(s): Thyroid function, thyroid peroxidase antibody, thyroglobulin antibody, ultrasound, and local symptoms were measured at baseline and up to 24 months. Results: Nodule volume reduction at 24 months was: 71.3 13.4 vs 47.4 5.5%, group A (LAT+131I) vs group B (131I), respectively; P < .001). In group A (LAT+131I), a reduction in radioiodine-administered activity was obtained (-21.1 8.1%). Local symptom score demonstrated a more rapid reduction in group A (LAT+131I). In three cases, no 131I treatment was needed after LAT. Conclusions: In this pilot study, combined LAT/131I treatment induced faster and greater improvement of local and systemic symptoms compared to 131I only. This approach seems a possible alternative to thyroidectomy in patients at refusal of surgery. PMID:24684455

Chianelli, M; Bizzarri, G; Todino, V; Misischi, I; Bianchini, A; Graziano, F; Guglielmi, R; Pacella, C M; Gharib, H; Papini, E

2014-07-01

255

Iodine and thyroid function.  

PubMed

Severe iodine deficiency causes hypothyroidism that results in impaired somatic growth and motor development in children. Mild and moderate iodine deficiencies cause multifocal autonomous growth of thyroid, which results in thyrotoxicosis. On the other hand, iodine excess is associated with the development of hypothyroidism and thyroid autoimmunity. In areas of iodine deficiency, a sudden increase in iodine intake is associated with transient hyperthyroidism. Recent studies demonstrated that long-term thyroid function of subjects who experienced both iodine deficiency and iodine excess during childhood tended to be abnormal despite optimization of their current iodine intake. Iodine status in the Korean Peninsula is very unique because people in the Republic of Korea have been shown to have predominantly excessive iodine levels, whereas the Democratic People's Republic of Korea is known to be an iodine-deficient area. Further research is warranted to verify the optimal ranges of iodine intake and to clarify the effects of iodine intake on thyroid disorders in the Korean Peninsula. PMID:24926457

Chung, Hye Rim

2014-03-01

256

Iodinated humic acids  

NASA Astrophysics Data System (ADS)

Humic acids are iodinated by elemental iodine and, if the iodine is present as iodide, by peroxidase-mediated reactions. It is demonstrated that iodination of humic acids leads to a product with a uniform distribution of iodine. It could not be unambiguously verified whether the enzymatically mediated iodination is a direct reaction between a peroxidase-iodine complex and the humic acid molecule or a two-step reaction in which the enzyme creates elemental iodine, which consecutively reacts with the humic acid. Based on a simple model of a reaction between sites in the humic acids available for iodination and the electrophilic iodinating species, it was concluded that the reaction should be described as an equilibrium with a logarithmic equilibrium constant of approximately 4. The number of sites available for iodination was, in the humic acids studied, determined to be approximately 410-4 per gram humic acid. The different parameters influencing the enzymatically controlled iodination of humic acids are discussed.

Christiansen, Jesper V.; Carlsen, Lars

257

[Iodine deficiency during pregnancy ].  

PubMed

Iodine is an essential micronutrient, it would be administered every day with our diet. The main role of this micronutrient is the synthesis of thyroid hormone. Thyroid hormones are related with brain development and metabolic regulation. Iodine deficit is related with goitre, and an important problem "diseases related with iodine deficiency", including high rate of neonatal mortality, decrease of intelligence, delayed of growth, high rate of aborts and congenital abnormalities.A risk group is pregnant women. Some authors have been demonstrated the utility of iodine supplementation during pregnancy. A systematic review of Cochrane group has shown that iodine supplementation during pregnancy decreased neonatal mortality RR 0.71 (0.56-0.9), and decrease the incidence of cretinism in children under 4 years RR 0.27 (0.12-0.6). As final recommendations, a program in pregnant women must be development to treat with iodine such as we make with folic acid. Pills with iron and iodine (1 mg iron and 25 ug iodine) have been demonstrated better results that pills with iodine. Tablets are the main presentation due to the role of the women in our Society and the work time. Programs of iodine enriched salt have been demonstrated a follow up of 50%. PMID:16386080

de Luis, D A; Aller, R; Izaola, O

2005-09-01

258

Iodination of hydroxyanthraquinones  

SciTech Connect

A method is proposed for the iodination of hydroxyanthraquinones with iodine and iodic acid in acetic acid in the presence of sodium acetate. The iodination of 2-hydroxyanthraquinone leads to 1,3-diioso-2-hydroxyanthraquinone. In the case of 1-hydroxyanthraquinone it is possible to obtain either 2-iodo-1-hydroxyanthraquinone or 2,4-diiodo-1-hydroxyanthraquinone. 4-Iodo-1-methoxyanthraquinone is formed during the iodination of 1-methoxyanthraquinone. The 2,6-diiodo, 2,7-diiodo, and 3-iodo derivatives were obtained from 1,5-, 1,8-, and 1,2-dihydroxyanthraquinones.

Galevskaya, T.P.; Moroz, A.A.; Myasnikova, R.N.; Shvartsberg, M.S.

1988-07-20

259

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

SciTech Connect

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.

Wang, C.P.

1986-01-01

260

Laser satellite power systems  

SciTech Connect

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.

Walbridge, E.W.

1980-01-01

261

Iodination of Cobrotoxin.  

National Technical Information Service (NTIS)

Neither maximal nor submaximal iodination of cobrotoxin, a neurotoxic protein isolated from the venom of the Taiwan cobra (Naja naja atra) with IC1 at pH 9-0, caused any loss of lethality or antigenicity. Only tyrosine residues in cobrotoxin were iodinate...

C. C. Chang C. C. Yang J. S. Huang K. H. Ling S. S. Liu

1972-01-01

262

Organic iodine chemistry  

Microsoft Academic Search

A shared-cost action on Organic Iodine Chemistry has been completed as part of the CEC 4th Framework programme on Nuclear Fission Safety. Organisations from four EC countries are involved in an integrated programme of experiments and analysis to help clarify the phenomenology, and to increase confidence in the modelling of iodine behaviour in containment. The project is focused on identifying

S Dickinson; H. E Sims; E Belval-Haltier; D Jacquemain; C Poletiko; F Funke; S Hellmann; T Karjunen; R Zilliacus

2001-01-01

263

Spaceborne Photonics Institute  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

264

AlGaAs-GaAs quantum-well lasers for direct solar photopumping  

NASA Technical Reports Server (NTRS)

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

Unnikrishnan, Sreenath; Anderson, Neal G.

1991-01-01

265

Iodine Clock Reaction.  

ERIC Educational Resources Information Center

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)

Mitchell, Richard S.

1996-01-01

266

Iodine in Finnish foods.  

PubMed

The iodine content of Finnish foods was analysed and the average daily intake of iodine estimated according to national food consumption statistics. The average calculated intake was 340 micrograms/d/person, although an extensive seasonal variation was found in the estimate for the summer season (280 micrograms) and for the winter season (400 micrograms). The intake is from 4 to 5 times greater now than it was in the mid 1950's, when endemic goitre was common in Finland. The most significant sources of iodine in the average Finnish diet are dairy products, which also cause the seasonal variation in intake. Iodized table salt and eggs are other important sources. The present level of intake can be considered adequate and the further intensification of prohylactic practices with iodine unnecessary. PMID:7085204

Varo, P; Saari, E; Paaso, A; Koivistoinen, P

1982-01-01

267

The Iodination of Dicarbahexaboranes.  

National Technical Information Service (NTIS)

The Al2I6-catalyzed iodination of 4,5-C2B4H8 produces the enantiomorphs 3-IC2B4H7 and 6-IC2B4H7. No HI was observed. The iodination of C2B4H6 (with Al2I6 at 75C.) similarly formed H2 and a 20% yield of 2-IC2B4H5. The nmr and mass spectra of these iodocarb...

T. J. Reilly A. B. Burg

1972-01-01

268

(Iodine and tellurium chemistry)  

SciTech Connect

The traveler worked with scientists from Great Britain, France, Canada, and the Federal Republic of Germany to produce a program and structure for the Second CSNI Specialists' Workshop on the Chemistry of Iodine in Reactor Safety. This workshop will be held on June 2--3, 1988, in Toronto, Canada. In addition to planning the workshop, there were informal discussions about the status of iodine research in the Federal Republic of Germany and in Canada.

Beahm, E.C.

1988-03-16

269

IODINE AND THE THYROID  

PubMed Central

1. Amphibian metamorphosis depends upon the amount of iodine secured by the larv; the greater the quantity the more rapid the differentiation. 2. Bromine is physiologically inert when fed even in large quantities to frog larv, hence it cannot be substituted for iodine. Bromine feeding has no effect on the thyroid. 3. Iodine is the active constituent of the thyroid gland, in the Anura at any rate, and functions within the body by stimulating intracellular oxidations; it is apparently specific in its action. 4. The basal metabolism of patients suffering from athyreosis, whose metabolism is 40 per cent below normal, is very likely held at this figure and prevented from sinking lower to the death point by the introduction of iodine into the body through food and water. 5. The thyroid gland is an organ the function of which is the extraction from the circulation, storage, and supplying to the organism, under the pressure of its needs, the small quantities of iodine taken into the body. The chief function of this gland then is the utilization of iodine in small quantities.

Swingle, W. W.

1919-01-01

270

Iodine supplementation in the newborn.  

PubMed

Iodine deficiency can be defined as the world's greatest single cause of preventable brain damage. Fetal and neonatal hypothyroidism, caused by iodine deficiency can be prevented prior to conception and then during pregnancy and lactation when an adequate iodine supplementation is ensured. Extremely low birth weight preterm babies risk having a negative iodine balance status in the first weeks of life, exacerbating the hypothyroxinaemia of the prematurity. It is important to ensure that these babies are provided with an adequate iodine intake from the first days of life. Mothers and newborns should avoid environmental iodine excess during pregnancy or lactation. PMID:24448111

Ghirri, Paolo; Lunardi, Sara; Boldrini, Antonio

2014-01-01

271

Lasers.  

ERIC Educational Resources Information Center

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)

Schewe, Phillip F.

1981-01-01

272

Iodine deficiency disorders in Europe.  

PubMed Central

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.

Delange, F.; Burgi, H.

1989-01-01

273

Photoacoustic Studies on Iodine.  

NASA Astrophysics Data System (ADS)

A photoacoustic cavity was constructed which employs a temperature-controlled cylindrical cavity with optical windows at either end. It was operated in the lowest longitudinal mode using a small electret microphone for detecting the acoustic signal and a photomultiplier tube for detecting the optical signal. Molecular Iodine was used as the specimen gas and argon as the buffer gas. The photoacoustic characteristics of the system were studied. Iodine molecules, excited periodically by intensity modulated optical radiation (xenon discharge), de-excited by non-radiative processes which result in pressure waves having the same modulation frequency as that of the light. These pressure waves are detected as acoustical pulses by the microphone situated in the wall of the cavity. Studies were conducted for different pressures of buffer gas (100 torr to 800 torr) at several different Iodine pressures in the range between 0.3 and 1 torr. The longitudinal mode of excitation provides an opportunity to compare the response of the cavity under acoustical excitation with that under optical excitation. The relevant parameters in the investigation were: Q, the quality factor of the cavity; the resonant frequency, partial pressures of argon and Iodine; temperature; and the signal amplitude. It was found that the Q of the cavity was well -behaved following the theoretically predicted dependence on SQRT.(P and on T('- 3/4). The absorption coefficient of Iodine determined photometrically, increased with increasing argon pressure up to a limiting value of pressure that depended on Iodine concentration. The photoacoustic signal showed a similar increase with increasing argon pressure. This signal reached a limiting value at a pressure which corresponded closely with that found optically. This is taken to indicate that the extinction coefficient of Iodine in argon, at the level of dilution used in these studies, depends on the argon pressure. A method was developed for measuring the concentration of Iodine at low levels through application of the shift in the frequency of the longitudinal mode resonance of the cavity. Also, resonance technique was employed for determining the velocity of sound in argon. A value of 307.7 M/sec was established as compared with the value of 319 M/sec as reported in various standard handbooks.

Bhan, Avtar N.

274

Waveguide CO\\/sub 2\\/ lasers pumped by broad-band radiation  

Microsoft Academic Search

A quasi-CW CO[sub 2] laser system pumped transversely by broad-band radiation from high-temperature tantalum foils was developed in the laboratory for investigating the feasibility of a space-based solar-pumped laser system. Large-bore metal-dielectric waveguides (5 and 8 mm) using sapphire were successfully applied in this system because of better energy extraction and smaller cavity losses. Computational modeling of source pumping power

J. J. Change; W. H. Christiansen

1993-01-01

275

Iodine status in pregnancy.  

PubMed

The iodine status of 429 pregnant women in different trimesters from the lower socio-economic strata of the urban slums of Bombay was assessed using clinical and biochemical parameters. The total goitre rate (TGR) of 45% and a visible goitre rate (VGR) of 3.04% was observed. There was an evident increase in the TGR during the months of pregnancy. The urinary iodine excretion pattern revealed mild iodine deficiency. 55% of the women had urinary iodine excretion less than 5 mcg/dl with 13.2% having less than 2 mcg/dl. Elevated T3 and T4 levels were observed in 64 and 40% respectively of the women surveyed, while only 1.8% of them had TSH levels higher than the normal range. No significant difference in the levels of thyroid hormone (T3 or T4) was noted between the euthyroid and goitrous subjects. The mean TSH levels in euthyroid women were however significantly higher than those with signs of goitre. PMID:24352142

Dodd, N S; Madan, J

1993-09-01

276

Laser development for laser fusion applications research. Progress report, October 1977--March 1978  

SciTech Connect

Research progress is reported on three laser programs being developed for the commercialization of laser-fusion energy. The lasers include iodine, hydrogen fluoride and Group VI atoms (e.g., O, S, Se, Te). (TFD)

Not Available

1978-06-01

277

Two and three-photon absorption of iodine molecules via dissociative states  

Microsoft Academic Search

Iodine vapor was irradiated by focused dye laser light in the range of 450-610 nm. As a consequence of the irradiation of the laser light tuned near the dissociation level of the B state (approximately 500 nm), emission bands were observed at 385, 342, 287 and 270 nm by two- or three-photon absorption. When the energy of the laser light

K. Kasatani; M. Kawasaki; H. Sato; Y. Tanaka; K. Shibuya; K. Obi; I. Tanaka

1981-01-01

278

High-performance iodine fiber frequency standard.  

PubMed

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 2.310(-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

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

2011-12-15

279

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

280

Iodine Generator for Reclaimed Water Purification.  

National Technical Information Service (NTIS)

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 disp...

F. H. Schubert J. D. Powell R. A. Wynveen

1977-01-01

281

Intraluminal iodination of thyroglobulin  

SciTech Connect

The intraluminal distribution of newly synthesized (injection of (/sup 3/H)leucine) and newly iodinated (injection of Na/sup 125/I) proteins in thyroids of rats given T4 for 2 days was studied with quantitative electron microscopic autoradiography. Three, 4.5, and 6 h after (/sup 3/H)leucine about 90%, 85%, and 65%, respectively, of the luminal label was confined to the microvillus region. This distribution differed from that of newly iodinated protein; already 2 min after injection only about 30% of the grains was located over the microvillus region. The remaining 70% of the grains located outside the microvillus region formed a gradient towards the center of the lumen. The grain distributions 30 min and 2 h after Na/sup 125/I were similar to that present after 2 min. The distribution of grains after pulse labeling with Na/sup 125/I (injected 2 min before propylthiouracil and 2 h before fixation) was also similar to that found in rats injected with Na/sup 125/I alone, indicating that diffusion of labeled proteins in the lumen was very slow in T4-treated rats. A slow diffusion was also suggested by the presence of an unlabeled peripheral ring in follicle lumens of T4-treated rats injected with Na/sup 125/I 48 h before fixation. In normal rats given (/sup 3/H)leucine 3 h before fixation or Na/sup 125/I 1 h or 48 h before fixation the grains were homogeneously distributed in most follicle lumens. Together our findings indicate that (1) administration of T4 has effects on the diffusion properties of the colloid; (2) iodine is incorporated not only into newly synthesized thyroglobulin recently delivered to the follicle lumen but also into molecules already stored in the lumen; (3) a portion of the iodine incorporated into proteins is bound to molecules which are not in direct contact with thyroperoxidase in the apical plasma membrane.

Ofverholm, T.; Ericson, L.E.

1984-03-01

282

Iodine addition using triiodide solutions  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

283

[Iodine prophylaxis following nuclear accidents].  

PubMed

Radioactive iodine isotopes may be released to air to a varying degree during accidents with nuclear reactors. Iodine tablets, taken before or shortly after such release, protect against intake of radioactive iodine isotopes, but not against other radionuclides. Iodine prophylaxis can be a relevant countermeasure in Norway and will be implemented according to recommendations from the Crisis Committee for Nuclear and Radiological Emergencies. The Chernobyl accident confirmed that the risk for radiogenic thyroid cancer is much higher for foetuses and children and adolescents under 18 years. An epidemiological study showed that intake of iodine tablets could reduce the risk for thyroid cancer by a factor of three. For children, the WHO has therefore recommended a 10 mGy avertable dose to the thyroid. The Norwegian Radiation Protection Authority acknowledge the WHO guidelines and advise that the first priority of all emergency preparedness planning for potential releases that can cause dispersion of radioactive iodine, should be given to the protection of pregnant and breast-feeding women, newborns and children under 18 years. Iodine tablets should be taken immediately (preferably not later than a few hours) in situations where inhalation of radioactive iodine may occur. It should be underlined that iodine prophylaxis is one of several emergency countermeasures; other measures are sheltering and evacuation. The latter two countermeasures will protect not only from intake of radioactive iodine, but also against other radionuclides that may be released. Based on the present risk assessment in Norway, iodine tablets have been distributed to the counties north of Salten. In addition, there is an emergency stockpile of iodine tablets in Oslo. PMID:17205086

Jaworska, Alicja

2007-01-01

284

Criteria for the evaluation of laser solar energy converter systems  

NASA Technical Reports Server (NTRS)

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

Harries, W. L.

1985-01-01

285

The concept of a nuclear-laser rocket engine  

NASA Astrophysics Data System (ADS)

A concept for an hybrid nuclear-laser rocket engine is described. The use of a solar-pumped laser is proposed to resolve temperature limitations in the combustion chamber. The propulsive mass, normally heated in the active zone to 1000-2500 K, can be ultimately heated by laser energy to 20,000-30000 K, increasing the exhaust velocity of the propulsive mass. This would lead to a significant reduction in fuel mass requirement. A scenario for application of the system in Earth-Mars flight is described.

Osadchi, V. N.; Yudo, O. A.

1994-06-01

286

Iodine speciation in the Nile River estuary  

Microsoft Academic Search

During high- and low-flood periods, surface and bottom water samples were collected along the Nile River estuary for the voltammetric determination of dissolved iodine species. Iodine occurs in the estuary as iodate, iodide and organic iodine. Total iodine increases with salinity, showing a source feature in surface and bottom waters during high-flow indicating iodine input. During low-flow, total iodine showed

M. A. R Abdel-Moati

1999-01-01

287

Iodine Atoms Structured in (SN)x  

NASA Astrophysics Data System (ADS)

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.

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

1985-05-01

288

Global Modelling of Tropospheric Iodine  

NASA Astrophysics Data System (ADS)

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).

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

2013-04-01

289

Iodine content of food groups  

Microsoft Academic Search

The iodine content of several kinds of foods representing different product groups available on the Swiss market was analyzed by isotope dilution inductively coupled plasma mass spectrometry using the enriched long-lived nuclide 129I. Considerable variations in levels of iodine between single foodstuffs within food groups were found, which also applied for levels in different food groups. The contribution of the

M. Haldimann; A. Alt; A. Blanc; K. Blondeau

2005-01-01

290

Endemic goiter associated with high iodine intake.  

PubMed Central

OBJECTIVES: This study assessed the relation of iodine content of household water to thyroid size and urinary iodine excretion in an area with high iodine concentration in the water. METHODS: The iodine content of household water and indicators of iodine status (thyroid size and urinary iodine level) were assessed in selected villages in Jiangsu Province, China. RESULTS: Water iodine levels were positively correlated with urinary iodine levels and indicators of thyroid size at the township level. CONCLUSIONS: Excess iodine in household water was the likely cause of endemic goiter and elevated urinary iodine levels in the study area. This finding affects public health policy on the institution of universal salt iodization for the elimination of iodine deficiency disorders.

Zhao, J; Wang, P; Shang, L; Sullivan, K M; van der Haar, F; Maberly, G

2000-01-01

291

Laser-fusion program. Semiannual report, January--June 1973  

SciTech Connect

Brief discussions are given for each of the following areas of research covered during this report period: solid-state laser program, design analysis, component development, diagnostics, gas lasers, chemical lasers---the iodine laser, basic studies and advanced concepts, laser propagation, laser plasmas, laser fusion, isotope separation, and program resources. (MOW)

Sussman, S.S. (ed.)

1973-08-22

292

A Resonance Raman/Iodine Moessbauer Investigation of the Starch-Iodine Structure: Aqueous Solution and Iodine Vapor Preparations.  

National Technical Information Service (NTIS)

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 -12...

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

1980-01-01

293

Resonance Raman\\/iodine Moessbauer investigation of the starch-iodine structure: aqueous solution and iodine vapor preparations  

Microsoft Academic Search

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

Robert C. Teitelbaum; Stanley L. Ruby; Tobin J. Marks

1980-01-01

294

Urinary Iodine Concentrations Indicate Iodine Deficiency in Pregnant Thai Women but Iodine Sufficiency in Their School-Aged Children  

Microsoft Academic Search

The median urinary iodine concentration (UI) in school-aged children is recommended for assessment of iodine nutrition in populations. If the median UI is adequate in school-aged children, it is usually assumed iodine intakes are also adequate in the remaining population, including pregnant women. But iodine requirements sharply increase during pregnancy. In this study, our aim was to measure UI in

S. Gowachirapant; P. Winichagoon; L. Wyss; B. Tong; J. Baumgartner; A. Melse-Boonstra; M. B. Zimmermann

2009-01-01

295

Iodine-123 generator/iodination kit: a preliminary report  

SciTech Connect

Preliminary results are described of a xenon-123 filled device to serve as a combination iodine-123 generator/iodination kit. Xenon-123 is produced in the Brookhaven Linac Isotope Producer (BLIP) by the reaction /sup 127/I(p, 5n)/sup 123/Xe. The device consists of a small glass ampoule containing an internal glass breakseal and a flanged neck on which is crimped a multi-injection type septum. The ampoule contains a hydrogen sulfide atmosphere to assure that the iodine generated from the decay of the xenon is in the form of iodide. Following an adequate period for xenon-123 to decay (this period can be used for shipment), a needle is forced through the septum breaking the seal and residual gases are pumped off. The iodine-123 in the form of iodide can then be rinsed from the ampoule with any desired solvent or reagent added directly to the device to carry out an iodination in an enclosed environment. Preliminary results of both iodine recovery and iodinations have been promising.

Richards, P; Prach, T; Srivastava, S C; Meinken, G E

1980-01-01

296

Structure of polyvinylpyrrolidone-iodine (povidone-iodine).  

PubMed

Hydrogen triiodide adducts were prepared from N,N-dimethylacetamide, N-alkylpyrrolidone derivatives, and polyvinylpyrrolidone, and their structures were investigated by IR spectra and X-ray structure analyses and compared with the structure of povidone-iodine USP. The results suggest that the iodine in povidone-iodine USP is complexed by the polymer such that a proton is fixed via a short hydrogen bond between two carbonyl groups of two pyrrolidone rings and that a triiodide anion is bound ionically to this cation. PMID:529040

Schenck, H U; Simak, P; Haedicke, E

1979-12-01

297

Iodine Tagging Velocimetry in a Mach 10 Wake  

NASA Technical Reports Server (NTRS)

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

Balla, Robert Jeffrey

2013-01-01

298

Lasers.  

National Technical Information Service (NTIS)

The optical laser was first developed in 1960. Among the first medical applications for lasers was the dermatologic application of this Ruby laser in 1964. Since that time, the application of lasers in medical and surgical uses has grown quite extensively...

J. A. Werkhaven R. H. Ossoff D. Harris

1991-01-01

299

Radioactive Iodine Treatment for Hyperthyroidism  

MedlinePLUS

... for Hyperthyroidism Share: Fact Sheet Radioactive Iodine for Hyperthyroidism April, 2012 Download PDFs English Zulu Espanol Editors ... V. Hennessey, MD Leonard Wartofsky, MD What is hyperthyroidism? The thyroid gland, located at the front of ...

300

Evolutionary Optimization of Three-Photon Absorption in Molecular Iodine  

Microsoft Academic Search

We report on the application of an evolutionary algorithm to a noisy, dynamic optimization problem in chemistry: the maximization of three-photon absorption in molecular iodine. An evolution strategy is used in real-time in a closed loop experiment to search the space of physically realizable phase-modulated femtosecond laser pulses. The probability of three-photon absorption is estimated by measuring UV fluorescence. With

Robert Burbidge; Jem J. Rowland; Ross D. King; Nicholas T. Form; Benjamin J. Whitaker

2007-01-01

301

Croatia has reached iodine sufficiency.  

PubMed

This study was performed in 2002, 6 yr after the introduction of a new regulation on salt iodination with 25 mg KI/kg of salt. The aim of the study was to evaluate whether further significant positive results of improved iodine intake could be observed among schoolchildren in Croatia. A total of 927 schoolchildren of both sexes, aged 6-12 yr, were included in the study. In Croatia, with a population of 4,437,460 the research was implemented in four major geographical regions: the Northwestern, Slavonia, Northern Adriatic and Dalmatian regions. Investigations included randomly selected pupils from regional centers and neighboring smaller towns or villages. The results have revealed that thyroid volumes were within the normal range according to the provisional WHO/ICCIDD reference values for sonographic thyroid volume in iodine-replete school-age children, updated in 2001. A significant improvement in medians of urinary iodine excretion was detected in 2002: from 9 microg/dl in 1991 to 14.6 microg/dl in Zagreb, from 4.3 microg/dl in 1995 to 13.1 microg/dl in Split, from 9.4 microg/dl in 1997 to 14.2 microg/dl in Rijeka and from 13.4 microg/dl in 1997 to 14.7 microg/dl in Osijek. An overall median of 14.0 microg/dl of urinary iodine excretion was detected in Croatian schoolchildren. The control of salt at different levels, from production to consumption, including salt produced in all three Croatian salt plants and imported salt, revealed that Croatian salt is adequately iodized. From severe iodine deficiency before the 1950s, through mild-to-moderate iodine deficiency in the 1990s, Croatia has now reached iodine sufficiency. PMID:14669828

Kusi?, Z; Novosel, S A; Dabeli?, N; Punda, M; Roncevi?, S; Labar, Z; Lukinac, Lj; Nthig-Hus, D; Stanici?, A; Kai?-Rak, A; Mesaros-Kanjski, E; Karner, I; Smoje, J; Milanovi?, N; Kataleni?, M; Juresa, V; Sarnavka, V

2003-08-01

302

Lithium-iodine pacemaker cell  

SciTech Connect

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.

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

1980-01-01

303

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

NASA Astrophysics Data System (ADS)

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 ? 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.; Gmez Martn, 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.; Kly-Kullai, K.; Wittmann, M.; Noszticzius, Z.; Onel, L.; Furrow, S. D.; J. Phys. Chem. A, 2012, 116, 6630 6642

Gtz, Sven; Hoffmann, Thorsten

2014-05-01

304

The illusion of environmental iodine deficiency.  

PubMed

The distribution of endemic goitre in England and Wales was compared with the distribution of environmental iodine (atmospheric deposition, soil, surface water). Despite a very clear goitre belt through the west of England and Wales there was no patterning in the environmental iodine distribution. A clear seasonal variation in depositional iodine exists, with an unusually high concentration of iodine in March 1997. The temporal variation in iodine concentration is determined at the monthly and not the annual level. The presence of endemic goitre is no indicator of how iodine is distributed in the environment or vice versa! PMID:12901092

Stewart, A G; Carter, J; Parker, A; Alloway, B J

2003-03-01

305

Enabling lunar and space missions by laser power transmission  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

306

The changing epidemiology of iodine deficiency.  

PubMed

Globally, about 2 thousand million people are affected by iodine deficiency. Although endemic goitre is the most visible sign of iodine deficiency, its most devastating consequence is brain damage causing mental retardation in children. The relationship between iodine deficiency and brain damage was not clearly established until the 1980s when the term iodine deficiency disorders (IDDs), which encompass a spectrum of conditions caused by iodine deficiency, was introduced. This paradigm shift in the understanding of the clinical consequences of iodine deficiency led to a change in iodine deficiency assessment. The median urinary iodine excretion level has been recommended as the preferred indicator for monitoring population iodine deficiency status since 2001. The 2007 WHO urinary iodine data in schoolchildren from 130 countries revealed that iodine intake is still insufficient in 47 countries. Furthermore, about one-third of countries lack national estimates of the prevalence of iodine deficiency. The picture that has emerged from available data worldwide over the past two decades is that IDDs are not confined to remote, mountainous areas in developing countries, but are a global public health problem that affects most countries, including developed countries and island nations. The recognition of the universality of iodine deficiency highlights the need to develop and apply new strategies to establish and maintain sustainable IDD elimination and strengthen regular monitoring programmes. PMID:22473332

Li, Mu; Eastman, Creswell J

2012-07-01

307

Organic chemistry: A tuxedo for iodine atoms  

Microsoft Academic Search

Iodine atoms can be fitted with a chemical jacket to control the conversion of simple carbon chains into complex iodine-containing molecules. Previously, such reactions were only possible with enzymes.

Phil S. Baran; Thomas J. Maimone

2007-01-01

308

The Absorption Spectrum of Iodine Vapour  

ERIC Educational Resources Information Center

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)

Tetlow, K. S.

1972-01-01

309

Iodine Deficiency Common in Pregnancy, Pediatricians Warn  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Iodine Deficiency Common in Pregnancy, Pediatricians Warn Processed foods ... pregnant and breast-feeding women are deficient in iodine and should take a daily supplement containing iodide, ...

310

Iodine Deficiency in Vegetarians and Vegans  

Microsoft Academic Search

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 ?g\\/l in vegetarians and 78 ?g\\/l

I. Klime; E. ebokov

2003-01-01

311

Mineral resource of the month: iodine  

USGS Publications Warehouse

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.

Polyak, Dsire E.

2009-01-01

312

Perchlorate, iodine and the thyroid.  

PubMed

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

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

2010-02-01

313

Sublimation of Iodine at Various Pressures  

ERIC Educational Resources Information Center

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

Leenson, Ilya A.

2005-01-01

314

Iodine losses during Winkler titrations  

NASA Astrophysics Data System (ADS)

An experiment designed to measure iodine loss during the aliquot version of the Winkler titration for dissolved oxygen in seawater shows that 0.01-0.03 ml l -1 equivalent oxygen is lost at typical oceanic concentrations in the method presently used. A standardization technique, which mimics that employed during the titration of seawater samples, compensates for this iodine loss throughout the oceanic range. This result, contradicting an earlier report by GREEN and CARRITT (1966, Analyst, 91, 207-208), demonstrates that the whole-bottle method of oxygen titration is not to be preferred over the aliquot method.

Knapp, George P.; Stalcup, Marvel C.; Stanley, Robert J.

1991-01-01

315

The short- and long-term frequency stabilization of an injection-locked Nd:YAG laser in reference to a FabryPerot cavity and an iodine saturated absorption line  

Microsoft Academic Search

We have developed a wideband frequency-stabilized injection-locked Nd:YAG laser as a light source for the laser interferometric gravitational wave detector, in which short-term frequency stability of the laser improves the sensitivity of the interferometer and the long-term frequency stability aims for the stable long-time operation of the interferometer. The frequency of a 2-W injection-locked laser is locked to both a

Mitsuru Musha; Takeshi Kanaya; Ken'ichi Nakagawa; Ken-ichi Ueda

2000-01-01

316

Laser Welding in Space  

NASA Technical Reports Server (NTRS)

Solidification type welding process experiments in conditions of microgravity were performed. The role of convection in such phenomena was examined and convective effects in the small volumes obtained in the laser weld zone were observed. Heat transfer within the weld was affected by acceleration level as indicated by the resulting microstructure changes in low gravity. All experiments were performed such that both high and low gravity welds occurred along the same weld beam, allowing the effects of gravity alone to be examined. Results indicate that laser welding in a space environment is feasible and can be safely performed IVA or EVA. Development of the hardware to perform the experiment in a Hitchhiker-g platform is recomended as the next step. This experiment provides NASA with a capable technology for welding needs in space. The resources required to perform this experiment aboard a Shuttle Hitchhiker-pallet are assessed. Over the four year period 1991 to 1994, it is recommended that the task will require 13.6 manyears and $914,900. In addition to demonstrating the technology and ferreting out the problems encountered, it is suggested that NASA will also have a useful laser materials processing facility for working with both the scientific and the engineering aspects of materials processing in space. Several concepts are also included for long-term optimization of available solar power through solar pumping solid state lasers directly for welding power.

Workman, Gary L.; Kaukler, William F.

1989-01-01

317

Advanced prototype automated iodine monitor system  

NASA Technical Reports Server (NTRS)

The technique of detecting and measuring parts-per-million concentrations of aqueous iodine by direct spectrophotometric means is discussed, and development of a prototype Automated Iodine Monitoring/Controller System (AIMS) is elaborated. The present effort is directed primarily toward reducing the power requirement and the weight of the AIMS. Other objectives include determining the maximum concentration of iodine that can be dissolved in an alcohol solution, and in an aqueous potassium iodide solution. Also discussed are the effects of a no flow condition on iodine measurements and the effect of pH on spectrophotometric iodine determinations.

1976-01-01

318

Enzymic Iodination of Milk Proteins  

Microsoft Academic Search

RECENTLY, Pitney and Russell Fraser1 have reported studies in which they utilized, as a model system for antithyroid drug evaluation, a procedure based on that of Keston2 for the enzymic iodination of milk proteins. This has prompted us to outline some of our observations with a similar system using purified milk enzymes and proteins. Native casein in a finely suspensible

Mary T. McQuillan; R. K. Morton; P. G. Stanley; V. M. Trikojus

1954-01-01

319

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

PubMed

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

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

2014-08-01

320

Transcutaneous iodine absorption in adult patients with thyroid cancer disinfected with povidone-iodine at operation.  

PubMed

Povidone-iodine is used as disinfection in patients undergoing many kinds of operations. Several cases of thyroid dysfunction induced by transcutaneous absorption of povidone-iodine have been reported in small infants. However, transcutaneous absorption was not clearly reported in adults. The aim of this study was to assess transcutaneous absorption of iodine in patients who received single topical application with povidoneiodine and serial changes of urinary iodine excretion under the condition with a simple iodine-restricted diet in Japan, an iodine-sufficient area. Sixty-eight patients with thyroid carcinoma undergoing total thyroidectomy received single skin disinfection with either povidone-iodine (group A; n = 47) or chlohexidine gluconate, a noniodine containing biguanide (group B; n = 21). In group A, urinary iodine excretion on the first day after operation increased up to 7 times that of the preoperative value. The amounts of urinary iodine correlated positively with operating time. Increased urinary iodine, however, returned to preoperative values on the third or fifth day after operation. In group B, there was no increase in urinary iodine excretion and urinary iodine excretion was ranged from 54 to 193 microg/g of creatinine on the third day of operation. In conclusion, a large amount of povidone-iodine was absorbed through healthy skin even in adults. This may possibly interfere with scintigraphy or radioactive iodine treatment, or cause thyroid disinfection in susceptible patients. PMID:16029128

Tomoda, Chisato; Kitano, Hiroya; Uruno, Takashi; Takamura, Yuuki; Ito, Yasuhiro; Miya, Akihiro; Kobayashi, Kaoru; Matsuzuka, Fumio; Amino, Nobuyuki; Kuma, Kanji; Miyauchi, Akira

2005-06-01

321

Precise frequency measurements of iodine hyperfine transitions at 671 nm.  

PubMed

We report absolute frequency measurements on the a(1), a(10), and a(15) hyperfine components of the R(78) 4-6 line of (127)I(2). An external-cavity diode laser system at 671 nm is frequency-stabilized to the saturated absorption center obtained by modulation transfer spectroscopy in an iodine vapor cell. Its absolute frequency is measured by an optical frequency comb. The effect of pressure shift is investigated to obtain the absolute transition frequency at zero pressure. Our determination of the line centers reaches a precision of better than 40 kHz and will provide useful input for theoretical calculations. This frequency-stabilized laser can be used as a reference laser for the spectroscopy of lithium D lines. PMID:23458797

Huang, Yao-Chin; Chen, Hsuan-Chen; Chen, Shih-En; Shy, Jow-Tsong; Wang, Li-Bang

2013-03-01

322

Fourier-transform IR spectroscopic observation of gaseous nitrosyl iodine, nitryl iodine, and iodine nitrate  

SciTech Connect

Using the photolysis of I[sub 2]-NO[sub x]-N[sub 2], mixtures the nitrogen oxyiodines nitrosyl iodine (INO), nitryl iodine (INO[sub 2]), and iodine nitrate (IONO[sub 2]) have been produced in situ in the gas phase in a large glass reaction chamber and their infrared absorption spectra were recorded in the range 600-4,000 cm[sup [minus]1] at 298 [plus minus] 2 K. This is the first report of the IR gas-phase spectra of these compounds and also the very first report of the IR spectrum of IONO[sub 2]. IONO[sub 2] was observed to decay in the dark with a first-order rate coefficient of [approximately] 3.2 [times] 10[sup [minus]2] s[sup [minus]1] under the experimental conditions of the study. Although it is not clear if the decay is due entirely to thermal decay, it is much higher than the value generally used in model simulations of iodine chemistry in the troposphere; repercussions for the atmospheric iodine cycle are briefly discussed. Nitrogen pentoxide (N[sub 2]O[sub 5]) was also a product in the I[sub 2]-NO[sub 2]-N[sub 2] photolysis system used to produce IONO[sub 2]. The formation of N[sub 2]O[sub 5] is thought to involve the photolysis of IONO[sub 2] to give NO[sub 3] radicals, which with NO[sub 2] rapidly establish an equilibrium with N[sub 2]O[sub 5]. The possible use of this system as a continuous source of NO[sub 3] radicals for laboratory experiments is also considered.

Barnes, I.; Becker, K.H.; Starcke, J. (Bergische Univ., Wuppertal (Germany))

1991-11-28

323

International Symposium on Gas Flow and Chemical Lasers, 8th, Madrid, Spain, Sept. 10-14, 1990, Proceedings  

Microsoft Academic Search

Papers are presented on current research developments and applications related to high-powered lasers. Recent advances in excimer laser technology, electron-beam-pumped excimer lasers, discharge technology for excimer lasers, and pulsed XeF lasers are examined. Consideration is given to short-wavelength lasers, chemical oxygen iodine lasers, and vibrational chemical lasers. Papers are presented on CO2, CO, N2O lasers, coupled CO2 lasers, laser induced

Jose M. Orza; C. Domingo

1991-01-01

324

Geochemical Cycling of Iodine Species in Soils  

SciTech Connect

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.

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

2007-08-23

325

The role of iodine in human growth and development  

Microsoft Academic Search

Iodine is an essential component of the hormones produced by the thyroid gland. Thyroid hormones, and therefore iodine, are essential for mammalian life. Iodine deficiency is a major public health problem; globally, it is estimated that two billion individuals have an insufficient iodine intake. Although goiter is the most visible sequelae of iodine deficiency, the major impact of hypothyroidism due

Michael B. Zimmermann

2011-01-01

326

Laser spectroscopy and a home-built laser diode  

NSDL National Science Digital Library

A compilation of several project manuscripts completed by Bethel University undergraduates in PHY330, Optics during spring semester of 2010. The first describes iodine spectroscopy experiments using a New Focus Velocity tunable diode laser. The second project is rubidium spectroscopy performed using a home-built laser similar to the one used in the workshop. The workshop spectroscopy demonstration is a combination of these two projects, using a home-built stabilized diode laser at 633 nm to do simple Iodine spectroscopy. The final manuscript below describes the wavemeter work and operartion, written by a recent Bethel University physics graduate, Sarah Anderson.

2011-01-11

327

Theoretical studies of solar lasers and converters  

NASA Technical Reports Server (NTRS)

A second computer program was developed for the simulation of an n - C3F7I iodine laser. The computer program is given in Appendix A and a typical output from the computer program is illustrated in Appendix B.

Heinbockel, John H.

1988-01-01

328

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

NASA Technical Reports Server (NTRS)

Investigations of iodine species distribution of various aqueous solutions of iodine disinfectants and water from equilibrated suspensions of triodide and pentaiodide resins were done at the University of Colorado for the Center for Space Environmental Health during 1992 and 1993. Direct measurements of three individual iodine species: I(-), I2 and I3(-), were made. In addition three measures of total titratable iodine species were used. It has been found that I2 and I3(-) solutions produce a significant fraction of the non-disinfecting species iodine I(-), ranging from 50 to 80% of added iodine, respectively, at pH values of approximately 5. Correspondingly, I2 solutions produce more than twice the concentration of disinfecting iodine species per mass iodine dose than I3(-) solutions. Both I(-) and I2 species were found in aqeuous extracts of pentaiodide resin, although no soluble species were detected with triiodide resin.

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

1993-01-01

329

Storable, consumable pre-nascent iodine  

US Patent & Trademark Office Database

This discovery is storable, pre-nascent iodine that activates and: produces nascent iodine over a two-to-three-hour period within the body when diluted in water and consumed. The iodine is in a low concentration in a tincture of grain alcohol. A quantity of tincture is submerged in a glass container in an electrolytic bath between two electrodes and subjected to a specific amperage for a period of time. This action causes the diatomic bond of the iodine molecule to be broken with the iodine atom receiving excitation energy from the magnetic field. When diluted and consumed into the body, the nascent iodine is able to produce significant beneficial effects in the body.

2012-12-04

330

Exploding conducting film laser pumping apparatus  

DOEpatents

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.

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

1984-04-27

331

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy  

Microsoft Academic Search

The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine

Michel L. Schlegel; Pascal Reiller; Florence Mercier-Bion; Nicole Barr; Valrie Moulin

2006-01-01

332

Salivary gland dysfunction following radioactive iodine therapy  

SciTech Connect

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.

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

1983-02-01

333

Chemical Species of Iodine in Some Seaweeds II. Iodine-Bound Biological Macromolecules  

Microsoft Academic Search

The distribution of iodine in various biological macromolecules in Sargassum kjellmanianum was studied using neutron activation analysis combined with chemical and biochemical separation techniques. The results indicate that iodine is mainly bound with protein, part of iodine with pigment and polyphenol, and little with polysaccharides, such as algin, fucoidan and cellulose. This result is significant for the mechanism of enriching

Xiaolin Hou; Xiaojun Yan; Chifang Chai

2000-01-01

334

Molecular environment of iodine in naturally iodinated humic substances: Insight from X-ray absorption spectroscopy  

NASA Astrophysics Data System (ADS)

The molecular environment of iodine in reference inorganic and organic compounds, and in dry humic and fulvic acids (HAs and FAs) extracted from subsurface and deep aquifers was probed by iodine L 3-edge X-ray absorption spectroscopy. The X-ray absorption near-edge structure (XANES) of iodine spectra from HAs and FAs resembled those of organic references and displayed structural features consistent with iodine forming covalent bonds with organic molecules. Simulation of XANES spectra by linear combination of reference spectra suggested the predominance of iodine forming covalent bonds to aromatic rings (aromatic-bound iodine). Comparison of extended X-ray absorption fine structure (EXAFS) spectra of reference and samples further showed that iodine was surrounded by carbon shells at distances comparables to those for references containing aromatic-bound iodine. Quantitative analysis of EXAFS spectra indicated that iodine was bound to about one carbon at a distance d (I-C) of 2.01(4)-2.04(9) , which was comparable to the distances observed for aromatic-bound iodine in references (1.99(1)-2.07(6) ), and significantly shorter than that observed for aliphatic-bound iodine (2.15(2)-2.16(2) ). These results are in agreement with previous conclusions from X-ray photoelectron spectroscopy and from electrospray ionization mass spectrometry. These results collectively suggest that the aromatic-bound iodine is stable in the various aquifers of this study.

Schlegel, Michel L.; Reiller, Pascal; Mercier-Bion, Florence; Barr, Nicole; Moulin, Valrie

2006-11-01

335

Automated iodine monitor system. [for aqueous solutions  

NASA Technical Reports Server (NTRS)

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.

1973-01-01

336

Amniotic fluid iodine concentrations do not vary in pregnant women with varying iodine intake.  

PubMed

Iodine deficiency is an important clinical and public health problem. Its prevention begins with an adequate intake of iodine during pregnancy. International agencies recommend at least 200 microg iodine per d for pregnant women. We assessed whether iodine concentrations in the amniotic fluid of healthy pregnant women are independent of iodine intake. This cross-sectional, non-interventional study included 365 consecutive women who underwent amniocentesis to determine the fetal karyotype. The amniocentesis was performed with abdominal antisepsis using chlorhexidine. The iodine concentration was measured in urine and amniotic fluid. The study variables were the intake of iodized salt and multivitamin supplements or the prescription of a KI supplement. The mean level of urinary iodine was 139.0 (SD 94.5) microg/l and of amniotic fluid 15.81 (SD 7.09) microg/l. The women who consumed iodized salt and those who took a KI supplement had significantly higher levels of urinary iodine than those who did not (P = 0.01 and P = 0.004, respectively). The urinary iodine levels were not significantly different in the women who took a multivitamin supplement compared with those who did not take this supplement, independently of iodine concentration or multivitamin supplement. The concentrations of iodine in the amniotic fluid were similar, independent of the dietary iodine intake. Urine and amniotic fluid iodine concentrations were weakly correlated, although the amniotic fluid values were no higher in those women taking a KI supplement. KI prescription at recommended doses increases the iodine levels in the mother without influencing the iodine levels in the amniotic fluid. PMID:18205989

Garca-Fuentes, Eduardo; Gallo, Manuel; Garca, Laureano; Prieto, Stephanie; Alcaide-Torres, Javier; Santiago, Piedad; Velasco, Ins; Soriguer, Federico

2008-06-01

337

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

Microsoft Academic Search

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

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

1980-01-01

338

Consuming iodine enriched eggs to solve the iodine deficiency endemic for remote areas in Thailand  

PubMed Central

Background Evidence showed that the occurrence of iodine deficiency endemic areas has been found in every provinces of Thailand. Thus, a new pilot programme for elimination of iodine deficiency endemic areas at the community level was designed in 2008 by integrating the concept of Sufficient Economic life style with the iodine biofortification of nutrients for community consumption. Methods A model of community hen egg farm was selected at an iodine deficiency endemic area in North Eastern part of Thailand. The process for the preparation of high content iodine enriched hen food was demonstrated to the farm owner with technical transfer in order to ensure the sustainability in the long term for the community. The iodine content of the produced iodine enriched hen eggs were determined and the iodine status of volunteers who consumed the iodine enriched hen eggs were monitored by using urine iodine excretion before and after the implement of iodine enrichment in the model farm. Results The content of iodine in eggs from the model farm were 93.57 ?g per egg for the weight of 55 - 60 g egg and 97.76 ?g for the weight of 60 - 65 g egg. The biological active iodo-organic compounds in eggs were tested by determination of the base-line urine iodine of the volunteer villagers before and after consuming a hard boiled iodine enriched egg per volunteer at breakfast for five days continuous period in 59 volunteers of Ban Kew village, and 65 volunteers of Ban Nong Nok Kean village. The median base-line urine iodine level of the volunteers in these two villages before consuming eggs were 7.00 and 7.04 ?g/dL respectively. After consuming iodine enriched eggs, the median urine iodine were raised to the optimal level at 20.76 ?g/dL for Ban Kew and 13.95 ?g/dL for Ban Nong Nok Kean. Conclusions The strategic programme for iodine enrichment in the food chain with biological iodo-organic compound from animal origins can be an alternative method to fortify iodine in the diet for Iodine Deficiency Endemic Areas at the community level in Thailand.

2010-01-01

339

Iodine deficiency in pregnancy and the effects of maternal iodine supplementation on the offspring: a review.  

PubMed

The World Health Organization (WHO) recently increased their recommended iodine intake during pregnancy from 200 to 250 microg/d and suggested that a median urinary iodine (UI) concentration of 150-249 microg/L indicates adequate iodine intake in pregnant women. Thyrotropin concentrations in blood collected from newborns 3-4 d after birth may be a sensitive indicator of even mild iodine deficiency during late pregnancy; a <3% frequency of thyrotropin values >5 mU/L indicates iodine sufficiency. New reference data and a simple collection system may facilitate use of the median UI concentration as an indicator of iodine status in newborns. In areas of severe iodine deficiency, maternal and fetal hypothyroxinemia can cause cretinism and adversely affect cognitive development in children; to prevent fetal damage, iodine should be given before or early in pregnancy. Whether mild-to-moderate maternal iodine deficiency produces more subtle changes in cognitive function in offspring is unclear; no controlled intervention studies have measured long-term clinical outcomes. Cross-sectional studies have, with few exceptions, reported impaired intellectual function and motor skills in children from iodine-deficient areas, but many of these studies were likely confounded by other factors that affect child development. In countries or regions where <90% of households are using iodized salt and the median UI concentration in school-age children is <100 microg/L, the WHO recommends iodine supplementation in pregnancy and infancy. PMID:19088150

Zimmermann, Michael B

2009-02-01

340

STUDY OF IODINE METABOLISM BY AN \\  

Microsoft Academic Search

By means of a prolonged administration, over a period of several weeks, ; of a constant amount of iodie labelled with I¹³¹ of known specific ; radioactivity, the stable iodine in the organism can be progressively replaced by ; the labelled iodine administered; after 4 or 5 weeks isotopic equilibrium'' is ; effectively reached. From then on, by measuring the

Cl. Simon; F. Morel

1957-01-01

341

Behavior of iodine in the Redox process  

Microsoft Academic Search

Experience already gained in the Bismuth Phosphate Process plants indicates that about 80 per cent of the iodine present in irradiated uranium is evolved during the dissolving process. Uranium irradiated under the present Hanford schedule and cooled 60 days contains about 300 curies of active iodine (largely i¹³¹) per ton. Dissolver solution prepared from such metal will, then, contain about

J. S. Kane; R. E. Burns

1952-01-01

342

The geochemistry of iodine a review  

Microsoft Academic Search

Iodine has long been recognised as an important element environmentally. Despite this there are many gaps in our knowledge of its geochemistry and even where information is available much of this is based on old data which, in the light of recent data, are suspect.Iodine forms few independent minerals and is unlikely to enter most rock-forming minerals. In igneous rocks

Ronald Fuge; Christopher C. Johnson

1986-01-01

343

Iodine transport analysis in the ESBWR.  

SciTech Connect

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.

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

2009-03-01

344

Prevalence of iodine deficiency disorders in adolescents.  

PubMed

In the present study the iodine status of 300 adolescent boys and girls was assessed by clinical examination and biochemical tests. The clinical examination revealed the total goitre rate (TGR) to be 65.2% among boys, and 69.6% among girls. The visible goitre rate (VGR) was 17.7% among boys and 21.1% among girls. Nutritional status of all adolescents was found to be poor as compared to their well-nourished counterparts. Using discriminant analysis it was found that age, height and weight of the adolescents were significantly related to goitre grade (p < 0.001), and they are important in prediction of goitre. Mild and moderate iodine deficiency were found to be prevalent among the adolescents. On the basis of urinary iodine/creatinine ratio, 38% of the adolescents were found to be suffering from mild iodine deficiency, i.e. average urinary iodine excretion between 50-100 mcg iodine/g creatinine. Moderate iodine deficiency (< 50 mcg iodine/g creatinine) was found to be prevalent among 12.4% of the adolescents. The results of this study indicate a high prevalence of mild and moderate IDD among the adolescents studied. PMID:1459681

Dodd, N S; Godhia, M L

1992-01-01

345

Mechanistic Role of Iodine in Breast Carcinogenesis.  

National Technical Information Service (NTIS)

There is both considerable interest and ignorance in the possible role of iodine in the etiology and prognosis of breast cancer. This project is the first step in elucidating a mechanistic role for iodine in breast carcinogenesis. The data that we have be...

K. S. Iwamoto

2005-01-01

346

Iodine generator for disinfecting reclaimed water  

NASA Technical Reports Server (NTRS)

System dispenses iodine into water tank automatically in quantities varying from 0.5 to 20 ppm. It stores 180-day supply of iodine crystals, sufficient to support six people consuming water at rate of 4.5 to 13.6 kg per person per day.

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

1974-01-01

347

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

NASA Astrophysics Data System (ADS)

Iodine tends to accumulate in thyroid, and radioactive 131I and 129I are threatening to human health both short-term and long-term, respectively. It is thus important to understand iodine behavior in surface environments. Possible iodine species are I-, IO3-, I2, and organo-iodine species. X-ray absorption near-edge structure (XANES) and high performance liquid chromatography (HPLC) connected to ICP-MS were used to determine iodine species in soil and pore water, respectively. Soil and pore water samples were collected at depths of 0 to 12 cm near a tube well in Yoro, Chiba, Japan, where surface soil is flooded with brine containing iodine of 5.8 mg/L. Soil samples were also collected at depths of 0 to 90 cm in Yakushima Island, Kagoshima, Japan. The soil samples were frozen, and iodine K-edge XANES were measured at BL01B1, SPring-8 (Hyogo, Japan). Soil samples were buried into resin and prepared as thin sections, and mapping of iodine in soil grain was obtained using ?-XRF analysis at BL37XU, SPring-8. HPLC-ICP-MS, equipped with anion exchange or size exclusion column, was used to determine iodine species in pore water. Yoro: The depth profile of iodine concentration in soil correlates quite well with that of organic carbon content. XANES spectra are almost identical to that of humic substances at any depth (Fig. 1). Iodine mapping shows that iodine exists in organic matter more than clay minerals and iron rich mineral. Iodine in pore water exists as I- and organic iodine bound to dissolved humic substances at 0-6 cm, and mainly as I- at 9-12 cm, respectively. Thus, iodine tends to be bound to organic materials in soil as organic iodine, where as iodine in pore water exists mainly as I-. Yakushima: Iodine concentration is higher in volcanic ash soil layer (25-55 cm) than surface organic rich soil layer (0-25 cm). XANES spectrum of volcanic ash soil was different from those of reference materials (Fig. 1). Volcanic ash soil in Yakushima contains imogolite and allophane. Iodide has greater affinity to imogolite than ferrihydrite[1]. It is suggested that clay minerals, such as imogolite, are also important to retain iodine especially in volcanic ash soils. [1] Yu et al. 1996, Geochim. Cosmochim. Acta 60, 4945-4956. Fig. 1 XANES spectra of standard materials and soil samples.

Shimamoto, Y.; Takahashi, Y.

2009-12-01

348

Lasers - Present and future research  

NASA Astrophysics Data System (ADS)

Laser research is reviewed in regards to applications and with particular attention to work in French laboratories. Inertial confinement fusion requires high energy deposition in 0.1-10 ns times, and efforts to devise suitable laser systems are outlined. Exciplex lasers are presented, including halogen and rare-gas halide lasers, rare gas and alkaline dimers, and trimer lasers. Optical and chemical pumping of iodine lasers are examined, and applications for photochemistry, isotope separation, and spectroscopy are discussed. Military uses of low energy CO2 waveguide lasers and chemical and CO2 lasers as weapons are mentioned, along with research intended for industrial applications of lasers. Finally, work in progress for optical telecommunications and free electron lasers, in addition to X ray and nuclear pumped lasers, is indicated.

Philippe, P.

1981-11-01

349

Risk of Suboptimal Iodine Intake in Pregnant Norwegian Women  

PubMed Central

Pregnant women and infants are exceptionally vulnerable to iodine deficiency. The aims of the present study were to estimate iodine intake, to investigate sources of iodine, to identify predictors of low or suboptimal iodine intake (defined as intakes below 100 ?g/day and 150 ?g/day) in a large population of pregnant Norwegian women and to evaluate iodine status in a sub-population. Iodine intake was calculated based on a validated Food Frequency Questionnaire in the Norwegian Mother and Child Cohort. The median iodine intake was 141 ?g/day from food and 166 ?g/day from food and supplements. Use of iodine-containing supplements was reported by 31.6%. The main source of iodine from food was dairy products, contributing 67% and 43% in non-supplement and iodine-supplement users, respectively. Of 61,904 women, 16.1% had iodine intake below 100 ?g/day, 42.0% had iodine intake below 150 ?g/day and only 21.7% reached the WHO/UNICEF/ICCIDD recommendation of 250 ?g/day. Dietary behaviors associated with increased risk of low and suboptimal iodine intake were: no use of iodine-containing supplements and low intake of milk/yogurt, seafood and eggs. The median urinary iodine concentration measured in 119 participants (69 ?g/L) confirmed insufficient iodine intake. Public health strategies are needed to improve and secure the iodine status of pregnant women in Norway.

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

2013-01-01

350

[Analytical aspects of the semiquantitative determination of urinary iodine using ferroin: value of rapid screening for iodine deficiency or excess].  

PubMed

Iodine is an essential element for thyroid hormone synthesis. Iodine disorders induced biological and/to clinical expression of thyroid dysfunction. Inappropriate iodine intake (by default or by excess) is worrying in terms of public health in France regarding the iodine deficiency and the frequency of iatrogen iodine overloads. Urinary iodine determination which generally implicates the use of a cerimetric method, is an useful tool to evaluate iodine intakes. In this study, we described the analytical aspects of a semiquantitative method of urinary iodine using a redox indicator, ferroin. This method allows the screening of iodine excess or deficiency in a short time (< 3 hours) with a good specificity and sensitivity. Since this assay does not require specific apparatus, it could be easily developed in clinical chemistry laboratories for the detection of inappropriate iodine intakes, and could be useful for prevention programs of iodine deficiency. PMID:15297242

Plantin-Carrenard, E; Cattan, F; Aurengo, A; Dumrat, B; Foglietti, M-J; Beaudeux, J-L

2004-01-01

351

Thermochemistry of small iodine species  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

352

Urinary iodine concentrations indicate iodine deficiency in pregnant Thai women but iodine sufficiency in their school-aged children.  

PubMed

The median urinary iodine concentration (UI) in school-aged children is recommended for assessment of iodine nutrition in populations. If the median UI is adequate in school-aged children, it is usually assumed iodine intakes are also adequate in the remaining population, including pregnant women. But iodine requirements sharply increase during pregnancy. In this study, our aim was to measure UI in pairs of pregnant women and their school-aged children from the same family, who were sharing meals, to directly assess whether a household food basket that supplies adequate iodine to school-aged children also meets the needs of pregnant women. UI was measured in spot urine samples from pairs (n = 302) of healthy pregnant mothers and their school-aged children in metropolitan Bangkok, Thailand. A dietary questionnaire was completed. The UI [median (range)] in the pregnant women {108 (11-558) microg/L [0.85 (0.086-4.41) micromol/L]} were lower than those of their school-aged children {200 (25-835) microg/L [1.58 (0.20-6.52) micromol/L]} (P < 0.001), indicating optimal iodine status in the children but mild-to-moderate iodine deficiency in their pregnant mothers. The estimated iodine intakes in the 2 groups were in the range of 130-170 microg/d. There was a modest positive correlation between UI in the pairs (r = 0.253; P < 0.01). A higher frequency of seafood meals was a significant predictor of UI in both groups, but household use of iodized salt was not. These data suggest the median UI in school-aged children should not be used as a surrogate for monitoring iodine status in pregnancy in central Thailand; pregnant women should be directly monitored. PMID:19403711

Gowachirapant, Sueppong; Winichagoon, Pattanee; Wyss, Laura; Tong, Bennan; Baumgartner, Jeannine; Melse-Boonstra, Alida; Zimmermann, Michael B

2009-06-01

353

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

PubMed Central

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.

Backer, H; Hollowell, J

2000-01-01

354

Iodine speciation in rain, snow and aerosols  

NASA Astrophysics Data System (ADS)

Iodine oxides, such as iodate, should be the only thermodynamically stable sink species for iodine in the troposphere. However, field observations have increasingly found very little iodate and significant amounts of iodide and soluble organically bound iodine (SOI) in precipitation and aerosols. The aim of this study was to investigate iodine speciation, including the organic fraction, in rain, snow, and aerosols in an attempt to further clarify aqueous phase iodine chemistry. Diurnal aerosol samples were taken with a 5 stage cascade impactor and a virtual impactor (PM2.5) from the Mace Head research station, Ireland, during summer 2006. Rain was collected from Australia, New Zealand, Patagonia, Germany, Ireland, and Switzerland and snow was obtained from Greenland, Germany, Switzerland, and New Zealand. Aerosols were extracted from the filters with water and all samples were analysed for total soluble iodine (TSI) by inductively coupled plasma mass spectrometry (ICP-MS) and iodine speciation was determined by coupling an ion chromatography unit to the ICP-MS. The median concentration of TSI in aerosols from Mace Head was 222 pmol m-3 (summed over all impactor stages) of which the majority was associated with the SOI fraction (median day: 904%, night: 942% of total iodine). Iodide exhibited higher concentrations than iodate (median 6% vs. 1.2% of total iodine), and displayed significant enrichment during the day compared to the night. Interestingly, up to 5 additional, presumably anionic iodo-organic peaks were observed in all IC-ICP-MS chromatograms, composing up to 15% of the TSI. Soluble organically bound iodine was also the dominant fraction in all rain and snow samples, with lesser amounts of iodide and iodate (iodate was particularly low in snow). Two of the same unidentified peaks found in aerosols were also observed in precipitation from both Southern and Northern Hemispheres. This suggests that these species are transferred from the aerosols into precipitation and that they have either a relatively long lifetime or are rapidly recycled. It is thought that SOI is formed by reactions between HOI or I2 and organic matter derived from the ocean surface layer. SOI may then photolytically decompose to yield iodide and the unidentified species. The data in this study show that iodine oxides are the least abundant species in rain, snow, and aerosols and therefore considerably more effort is required on aqueous phase iodine chemistry for a holistic understanding of the iodine cycle.

Gilfedder, B. S.; Lai, S. C.; Petri, M.; Biester, H.; Hoffmann, T.

2008-10-01

355

History of U.S. Iodine Fortification and Supplementation  

PubMed Central

Iodine is a micronutrient required for thyroid hormone production. This review highlights the history of the discovery of iodine and its uses, discusses the sources of iodine nutrition, and summarizes the current recommendations for iodine intake with a focus on women of childbearing age.

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

2012-01-01

356

Effect of iodine disinfection products on higher plants  

Microsoft Academic Search

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

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

1989-01-01

357

Re-emergence of iodine deficiency in Australia  

Microsoft Academic Search

Iodine is an essential nutrient for human growth and development. The thyroid gland is dependent upon iodine for production of thyroid hormone. It is a common perception that iodine deficiency is not a major public health concern in mainland Australia, with sporadic studies carried out about a decade ago showing average urinary iodine excretion levels of around 200 g\\/day. Recent

Mu Li; Gary Ma; Karmala Guttikonda; Steven C Boyages; Creswell J Eastman

2001-01-01

358

The nutritional iodine supply of Belgian neonates is still insufficient  

Microsoft Academic Search

Belgium used to be affected by mild iodine deficiency. Improvement in iodine nutrition has been recently documented in schoolchildren in Belgium in spite of the absence of any systematic programme of iodine supplementation. The question arises as to whether this 'silent iodine prophylaxis' affected also the neonates. A total of 185 random urine samples were collected from 90 full term

Roberta Ciardelli; Dominique Haumont; Danielle Gnat; Franoise Vertongen; Franois Delange

2002-01-01

359

Method and apparatus for removing iodine from a nuclear reactor coolant  

DOEpatents

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.

Cooper, Martin H. (Monroeville, PA)

1980-01-01

360

Computation of iodine species concentrations in water  

NASA Technical Reports Server (NTRS)

During an evaluation of the use of iodine as a water disinfectant and the development of methods for measuring various iodine species in water onboard Space Freedom, it became necessary to compute the concentration of the various species based on equilibrium principles alone. Of particular concern was the case when various amounts of iodine, iodide, strong acid, and strong base are added to water. Such solutions can be used to evaluate the performance of various monitoring methods being considered. The authors of this paper present an overview of aqueous iodine chemistry, a set of nonlinear equations which can be used to model the above case, and a computer program for solving this system of equations using the Newton-Raphson method. The program was validated by comparing results over a range of concentrations and pH values with those previously presented by Gottardi for a given pH. Use of this program indicated that there are multiple roots to many cases and selecting an appropriate initial guess is important. Comparison of program results with laboratory results for the case when only iodine is added to water indicates the program gives high pH values for the iodine concentrations normally used for water disinfection. Extending the model to include the effects of iodate formation results in the computer pH values being closer to those observed, but the model with iodate does not agree well for the case in which base is added in addition to iodine to raise the pH. Potential explanations include failure to obtain equilibrium conditions in the lab, inaccuracies in published values for the equilibrium constants, and inadequate model of iodine chemistry and/or the lack of adequate analytical methods for measuring the various iodine species in water.

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

1994-01-01

361

[Iodine content of mother's milk--Hungarian representative survey, 2006].  

PubMed

In Hungary, except for some small area, iodine content of soil, cultivated crops and potable water is low; therefore the iodine intake of Hungarian population is lower than the amount recommended by international organizations. The high iodine intake for pregnant and nursing women is important to ensure the appropriate iodine intake of fetus and nursing babies, as well. Aim: The objective of the study was to get a comprehensive picture of iodine content of mother's milk and to make recommendation for the level of iodine supplementation for pregnant and nursing women. Methods: Following a country-wide sampling, iodine content of 72 human milk samples were analyzed by inductively coupled plasma-mass spectrometry. Results: Iodine intake in 42 percent of babies is lower than the recommended amount which could remarkably influence the physical and mental development of infants. Conclusions: Iodine supplementation and consumption of food with high iodine content is highly recommended during pregnancy and nursing. PMID:19592336

Griff, Tams; Czak, Klra; Lugasi, Andrea; Martos, Eva

2009-07-26

362

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

SciTech Connect

Daily vaginal douching with polyvinylpyrrolidone-iodine in 12 euthyroid volunteers for 14 days resulted in a significant increase in serum total iodine concentration and urine iodine excretion. The increase in serum total iodine was associated with a marked decrease in 24-hour /sup 123/I uptake by the thyroid and a small but significant increase in serum thyrotropin (TSH) concentration. However, values for serum TSH never rose above the normal range. No significant changes in serum thyroxine (T4), free T4 index (FTI), or triiodothyronine concentrations were observed, although serum T4 and FTI did decrease slightly during treatment. The findings suggest that iodine is absorbed across the vaginal mucosa and that the subsequent increase in serum total iodine does induce subtle increases in serum TSH concentration. There was no evidence, however, of overt hypothyroidism in these euthyroid women.

Safran, M.; Braverman, L.E.

1982-07-01

363

A novel concept to derive iodine status of human populations from frequency distribution properties of a hair iodine concentration.  

PubMed

Today, human iodine deficiency is next to iron the most common nutritional deficiency in developed European and underdeveloped third world countries, respectively. A current biological indicator of iodine status is urinary iodine that reflects the very recent iodine exposure, whereas some long term indicator of iodine status remains to be identified. 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 the inductively coupled plasma mass spectrometry (ICP MS). Population (n870) hair iodine (IH) respective median was 0.499?gg(-1) (0.482 and 0.508?gg(-1)) for men and women, respectively, suggesting no sex related difference. We studied the hair iodine uptake by the logistic sigmoid saturation curve of the median derivatives to assess iodine deficiency, adequacy and excess. We estimated the overt iodine deficiency to occur when hair iodine concentration is below 0.15?gg(-1). Then there was a saturation range interval of about 0.15-2.0?gg(-1) (r(2)=0.994). Eventually, the sigmoid curve became saturated at about 2.0?gg(-1) and upward, suggesting excessive iodine exposure. Hair appears to be a valuable and robust long term biological indicator tissue for assessing the iodine body status. We propose adequate iodine status to correspond with the hair iodine (IH) uptake saturation of 0.565-0.739?gg(-1) (55-65%). PMID:24629671

Prejac, J; Vinjevi?, V; Drmi?, S; Skalny, A A; Mimica, N; Mom?ilovi?, B

2014-04-01

364

A povidone-iodine medicated dressing.  

PubMed

The iodine content of a tulle gras-type dressing medicated with povidone-iodine (Poviderm) has been measured and its potential efficacy in wound care explored by means of laboratory models. Simple tests demonstrated the ready diffusibility and antibacterial activity of povidone-iodine. Wound models clearly showed that the limiting factor for useful dressing life is extent of exudation. It seems likely that this dressing would provide good topical antibacterial prophylaxis and may reduce the bacterial burden of colonised wounds. The dressing should help contain wound bacteria and thus assist infection control. PMID:9791357

Lawrence, J C

1998-07-01

365

Method for immobilizing radioactive iodine  

DOEpatents

Radioactive iodine, present as alkali metal iodides or iodates in an aqueous solution, is incorporated into an inert solid material for long-term storage by adding to the solution a stoichiometric amount with respect to the formation of a sodalite (3M.sub.2 O.3Al.sub.2 O.sub.3. 6SiO.sub.2.2MX, where M=alkali metal; X=I.sup.- or IO.sub.3.sup.-) of an alkali metal, alumina and silica, stirring the solution to form a homogeneous mixture, drying the mixture to form a powder, compacting and sintering the compacted powder at 1073 to 1373 K (800.degree. to 1100.degree. C.) for a time sufficient to form sodalite.

Babad, Harry (Richland, WA); Strachan, Denis M. (Richland, WA)

1980-01-01

366

Autoradiography for iodine-125 seeds  

SciTech Connect

To study the interior design of model 6702 and 6711 iodine-125 seeds, contact autoradiographs were performed using mammography film. Improved resolution was obtained using a pin-hole camera with a hole of 0.1 mm [times] 0.1 mm. With these techniques, qualitative determination of the relative activity distribution within each seed was possible. The number of the activated resin spheres and the positions of the centers of these spheres can be exactly determined. A model calculation shows that variations in the arrangement of the activated spheres within a seed have a moderate influence on the dose distribution at source distances below 10 mm. Knowing the exact source configuration may be useful when comparing dose calculations with measured data for model 6702 [sup 125]I seeds which are currently employed in ophthalmic plaque and implant therapy of other tumors. 16 refs., 5 figs., 2 tabs.

Alberti, W.; Divoux, S. (Alfried Krupp Krankenhaus, Essen (Germany)); Pothmann, B.; Tabor, P. (Universitaetsklinikum, Essen (Germany)); Hermann, K.P.; Harder, D. (Universitaet Goettingen (Germany))

1993-04-02

367

Impact of iodine supplementation of dairy cows on milk production and iodine concentrations in milk  

Microsoft Academic Search

AIM: To determine the effect of iodine supplementation on milk production and iodine concentrations in milk for pasture-fed, seasonally calving dairy cows.METHODS: The study was run over two consecutive seasons on the same dairy farm. In Trial One, 294 Friesian dairy cows were either untreated or injected intramuscularly three times with iodised oil (2,370 mg iodine\\/dose) at the start of

ND Grace; GC Waghorn

2005-01-01

368

Iodine stress corrosion cracking of Zircaloy reactor cladding: iodine chemistry (a review)  

Microsoft Academic Search

This review covers chemical aspects of the iodine stress corrosion cracking (ISCC) pellet-cladding interaction (PCI) failures which have occurred in some reactors with UO2 fuel in unlined Zircaloy tubes. The cracking mechanism is discussed in relation to chemical factors. Cesium and iodine are released as fission products and form CsI but its dissociation iodine pressure p(I) is many orders of

P. S Sidky

1998-01-01

369

Evaluation of Accessibility of Iodinated Salt and Nutritional Iodine Status during Pregnancy  

PubMed Central

Background: To assess accessibility of iodinated salt and urinary iodine concentrations (UIC) during pregnancy. This cross-sectional study was carried out between October and December, 2009 in Urmia County, West Azerbaijan (WA), Iran. Methods: Data on demographic characteristics and iodinated salt accessibility were gathered through a questionnaire at 1st trimester. Household salt samples and urine samples (1st and 3rd trimesters) were analyzed for iodine content. Pregnant women (n=490) at 1st trimester were interviewed. Of these, 490 subjects (12 prenatal care centers) were enrolled. Results: All participants declared that they were exclusive users of iodinated salt. Segregation of the household salt samples according to iodine content (0, 8, 15 and 30 ppm) revealed that the respective distributions were 3.3%, 1.4%, 23.7% and 71.6%. Median UIC levels at 1st and 3rd trimesters were 73.5 ?g/L and 114?g/L respectively. Accordingly, 86% and 70% of participants exhibited UIC < 150 ?g/L. Conclusion: Median UIC during pregnancy in WA is markedly lower than those previously reported for regions with adequate iodine status in the country. Thus, extra iodine is needed to maintain adequate iodine store during gestation. In addition, this preliminary study reveals that a significant proportion (28%) of the household salt samples had low iodine content (? 15 ppm) although a level (>20 and <40 ppm) is mandatory in Iran. Further studies are deemed necessary to elucidate the cause(s) for manifestation iodine deficiency among pregnant women despite 20 years after iodine fortification strategy.

Rostami, R; Beiranvand, A; Khakhali, HR; Salary, S; Aghasi, MR; Nourooz-Zadeh, J

2012-01-01

370

Iodination and stability of somatostatin analogues: comparison of iodination techniques. A practical overview.  

PubMed

For iodination ((125/127)I) of tyrosine-containing peptides, chloramin-T, Pre-Coated Iodo-Gen() tubes and Iodo-Beads() (Pierce) are commonly used for in vitro radioligand investigations and there have been reliant vendors hereof for decades. However, commercial availability of these radio-iodinated peptides is decreasing. For continuation of our research in this field we investigated and optimized (radio-)iodination of somatostatin analogues. In literature, radioiodination using here described somatostatin analogues and iodination techniques are described separately. Here we present an overview, including High Performance Liquid Chromatography (HPLC) separation and characterisation by mass spectrometry, to obtain mono- and di-iodinated analogues. Reaction kinetics of (125/127)I iodinated somatostatin analogues were investigated as function of reaction time and concentration of reactants, including somatostatin analogues, iodine and oxidizing agent. To our knowledge, for the here described somatostatin analogues, no (127)I iodination and optimization are described. (Radio-)iodinated somatostatin analogues could be preserved with a >90% radiochemical purity for 1 month after reversed phase HPLC-purification. PMID:23339762

de Blois, Erik; Chan, Ho Sze; Breeman, Wouter A P

2012-01-01

371

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

PubMed Central

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.

2013-01-01

372

Nuclear pumped laser research at the Jet Propulsion Laboratory  

NASA Technical Reports Server (NTRS)

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.

Russell, G. R.

1979-01-01

373

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

Code of Federal Regulations, 2011 CFR

... Applicability; description of the iodine production subcategory. 415.430...MANUFACTURING POINT SOURCE CATEGORY Iodine Production Subcategory 415.430 Applicability; description of the iodine production subcategory. The...

2011-07-01

374

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

Code of Federal Regulations, 2012 CFR

... Applicability; description of the iodine production subcategory. 415.430...MANUFACTURING POINT SOURCE CATEGORY Iodine Production Subcategory 415.430 Applicability; description of the iodine production subcategory. The...

2012-07-01

375

Teaching the Rovibronic Spectroscopy of Molecular Iodine  

ERIC Educational Resources Information Center

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.

Williamson, J. Charles

2007-01-01

376

Tositumomab and Iodine I 131 Tositumomab  

Cancer.gov

This page contains brief information about tositumomab and iodine I 131 tositumomab and a collection of links to more information about the use of this drug, research results, and ongoing clinical trials.

377

The Electronic Spectrum of Iodine Revisited.  

ERIC Educational Resources Information Center

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)

McNaught, Ian J.

1980-01-01

378

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

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

379

Regenerable Iodine Water-Disinfection System  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

380

Iodine - Its possible role in tropospheric photochemistry  

Microsoft Academic Search

A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to

W. L. Chameides; D. D. Davis

1980-01-01

381

HRT MOCKUP IODINE REMOVAL AND RECOMBINER TESTS  

Microsoft Academic Search

Tests have been run in the HRT core system mockup which demonstrate that ; iodine can be successfully removed from dry steam by a silver bed. Such a bed is ; recommended to prevent iodine poisoning of the HRT recombiner catalyst. An added ; advantage will be removal of I¹³⁵ from circulation, whereby reducing ; neutron losses a Xe¹³⁵, a

Harley

1958-01-01

382

Absence of bacterial resistance to povidone iodine.  

PubMed Central

Povidone iodine is now being increasingly used in hospitals as an antiseptic. The possible habituation of bacteria to iodine was studied by serial passage of two strains of Pseudomonas aeruginosa, two strains of Escherichia coli, two strains of Klebsiella aerogenes, and one strain of Serratia marcescens in subinhibitory concentrations. After 20 passages, no significant change was observed in the minimal inhibitory concentration, minimal bactericidal concentration, and killing times between parent strains and 20th subcultures under standardized conditions.

Houang, E T; Gilmore, O J; Reid, C; Shaw, E J

1976-01-01

383

Chemical laser systems analysis  

SciTech Connect

This paper presents a means by which the chemical laser device weight can be minimized with respect to its performance and the device power minimized with respect to the target range. Chemical laser performance parameters such as the specific power and nozzle power flux are then used in conjunction with weight and propagation models to determine system effectiveness. A measure of merit is given by which systems can be contrasted. An illustrative example is included in which DF and Iodine laser systems are compared for an airborne scenario. 14 references.

Doughty, J.R.

1988-11-01

384

Exploding conducting film laser pumping apparatus  

DOEpatents

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.

Ware, Kenneth D. (San Diego, CA); Jones, Claude R. (Los Alamos, NM)

1986-01-01

385

Theoretical studies of solar lasers and converters  

NASA Technical Reports Server (NTRS)

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.

Heinbockel, John H.

1990-01-01

386

Effect of iodine disinfection products on higher plants  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

387

Ultraviolet gas-discharge lamp on iodine molecules  

NASA Astrophysics Data System (ADS)

The emission characteristics of a pulsed-periodic UV radiation source are reported. The source excited by a pulsed-periodic capacitive discharge initiated in helium-iodine vapor, neon-iodine vapor, or krypton-iodine vapor mixtures radiates in the spectral range 200-450 nm. It is shown that most of the plasma radiation power concentrates in the integral line of the iodine atom (206.2 nm) and in the D'- A' band of the iodine molecule with a maximum at 342 nm. The radiation intensity of the lamp is optimized in accordance with the partial pressure of the inert gases. The discharge plasma parameters that are of interest for simulating the process kinetics and the output characteristics of an UV source based on molecular iodine, atomic iodine, and xenon iodide are calculated in helium-iodine vapor and xenon-iodine vapor mixtures.

Shuaibov, A. K.; Minya, A. I.; Gomoki, Z. T.; Kalyuzhnaya, A. G.; Shchedrin, A. I.

2010-08-01

388

Optical design method for controlling laser beam profiles  

Microsoft Academic Search

By properly designing the laser optical resonator, an optimal match between brightness and coherence can be achieved. This paper discusses one such design for an oxygen iodine laser and shows measured beam profiles. The laser mode was shaped and optically relayed to a test specimen. Very uniform beams of high brightness were measured at the plane of the test sample.

Burton D. O'Neil; Vance A. Hedin; Carol E. Hines

1994-01-01

389

Maternal Iodine Status and Thyroid Volume during Pregnancy: Correlation with Neonatal Iodine Intake  

Microsoft Academic Search

Differences in pregnancy-associated alterations in thyroid vol- ume and urinary iodine (UI) excretion have been attributed to geographical variations in dietary iodine intake. In this study, ultrasound-measured thyroid volume and UI excretion were as- sessed during the 3 trimesters of pregnancy, at delivery, and at 6 weeks postpartum. Urine specimens also were obtained from moth- ers and both breast- and

P. P. A. Smyth; A. M. T. HETHERTON; D. F. SMITH; M. RADCLIFF; C. O'HERLIHY

1997-01-01

390

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

PubMed

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

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

2014-04-01

391

The iodine status of grazing sheep as monitored by concentrations of iodine in milk.  

PubMed

The iodine nutrition of grazing ewes was assessed from milk iodine concentrations. In 54 flocks sampled throughout Victoria, the mean milk iodine concentrations in ewes ranged from 79 to 1831 micrograms/l. In 2 flocks where newborn lambs had goitre the concentrations in ewes ranged from 45 to 98 micrograms/l. A marked seasonal variation was apparent when ewes in a flock were sampled at monthly intervals over 2 years. Milk iodine concentrations were highest at the end of summer, and were lowest in spring. In grazing ewes the milk iodine concentrations remained relatively constant throughout the day. In ewes given single oral doses of up to 2 mg iodine, milk iodine concentrations increased to maximum within 5 h, the increment being related to the dose administered, and decreased to pretreatment concentrations within 24 h. Milk iodine concentrations in ewes given 1 ml iodised oil intramuscularly remained significantly higher than untreated ewes in the same flock for 16 months after treatment. The effectiveness of the single injection was still apparent after 2 consecutive pregnancies in the ewes. PMID:6093759

Azuolas, J K; Caple, I W

1984-07-01

392

Addition of chlorine during water purification reduces iodine content of drinking water and contributes to iodine deficiency.  

PubMed

Drinking water is the major natural source of iodine in many European countries. In the present study, we examined possible sites of iodine loss during the usual water purification process.Water samples from 6 sites during the technological process were taken and analyzed for iodine content. Under laboratory circumstances, prepared iodine in water solution has been used as a model to test the effect of the presence of chlorine. Samples from the purification sites revealed that in the presence of chlorine there is a progressive loss of iodine from the water. In the chlorine concentrations employed in the purification process, 24-h chlorine exposure eliminated more than 50% of iodine when the initial iodine concentration was 250 ?g/l or less. Iodine was completely eliminated if the starting concentration was 16 ?g/l.We conclude that chlorine used during water purification may be a major contributor to iodine deficiency in European communities. PMID:21623158

Samson, L; Czegeny, I; Mezosi, E; Erdei, A; Bodor, M; Cseke, B; Burman, K D; Nagy, E V

2012-01-01

393

Iodine overload and severe hypothyroidism in a premature neonate.  

PubMed

Use of iodinated skin disinfectants in the perinatal period can result in significant iodine overload of the neonate and transient hypothyroidism. The authors report a case of unusually severe hypothyroidism requiring L-thyroxine (L-T4) replacement therapy in a premature neonate after prolonged use of iodinated skin disinfectants for a complex skin lesion. Neonatal iodine overload should be minimized, and in cases with significant iodine exposure, thyroid-stimulating hormone should be monitored, especially in preterm neonates who are exquisitely sensitive to the antithyroid effects of iodine excess. PMID:15750908

Khashu, Minesh; Chessex, Philippe; Chanoine, Jean-Pierre

2005-02-01

394

[Application of iodine metabolism analysis methods in thyroid diseases].  

PubMed

The main physiological role of iodine in the body is to synthesize thyroid hormone. Both iodine deficiency and iodine excess can lead to severe thyroid diseases. While its role in thyroid diseases has increasingly been recognized, few relevant platforms and techniques for iodine detection have been available in China. This paper summarizes the advantages and disadvantages of currently iodine detection methods including direct titration, arsenic cerium catalytic spectrophotometry, chromatography with pulsed amperometry, colorimetry based on automatic biochemistry, inductively coupled plasma mass spectrometry, so as to optimize the iodine nutrition for patients with thyroid diseases. PMID:23987480

Han, Jian-hua; Qiu, Ling

2013-08-01

395

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

DOEpatents

Materials and methods of synthesizing mixed-layered bismuth oxy-iodine materials, which can be synthesized in the presence of aqueous radioactive iodine species found in caustic solutions (e.g. NaOH or KOH). This technology provides a one-step process for both iodine sequestration and storage from nuclear fuel cycles. It results in materials that will be durable for repository conditions much like those found in Waste Isolation Pilot Plant (WIPP) and estimated for Yucca Mountain (YMP). By controlled reactant concentrations, optimized compositions of these mixed-layered bismuth oxy-iodine inorganic materials are produced that have both a high iodine weight percentage and a low solubility in groundwater environments.

Krumhansl, James L; Nenoff, Tina M

2013-02-26

396

[Iodine and thyroid: what a clinic should know].  

PubMed

The World Health Organization considers iodine deficiency as a major worldwide cause of mental and development diseases, estimating that about 13% of the world population is affected by diseases caused by iodine deficiency. Iodine is a trace element necessary for the synthesis of thyroid hormones which, since it cannot be formed by the organism, must be taken regularly with food. Fish and shellfish are generally a good source, because the ocean contains a considerable amount of iodine. On the contrary, plants which grow in iodine-deficient soils are poor in this element, as well as meat and other animal products fed in plants low in iodine. Salt is the best way for iodine supplementation. Cooking the food with iodized salt is a desirable practice because it guarantees the presence of this element. There are also other methods to provide iodine to the general population, such as adding iodine to drinking water or taking supplements of iodine. In pregnancy is recommended iodine supplementation, except in patients with known thyroid disorders. Iodine is an essential component of thyroid hormones (T4 and T3). Inadequate iodine intake leads to inadequate thyroid hormone production. The most important consequences of iodine deficiency, in the general population are goiter and hypothyroidism, and in the severe cases, mental retardation, cretinism and increased neo-natal and infant mortality. The International Council for the Control of Iodine Deficiency Disorders (ICCIDD) formed in 1985, with the only aim of achieving optimal iodine nutrition in the world, in cooperation with UNICEF and WHO. In Portugal, recent studies show significant deficiencies in pregnancy and The Portuguese Society of Endocrinology Diabetes and Metabolism, in partnership with General Directorate of Health, proposed an iodine supplementation during pregnancy with 150-200g/day. PMID:23069238

Santana Lopes, Maria; Jcome de Castro, Joo; Marcelino, Mafalda; Oliveira, Maria Joo; Carrilho, Francisco; Limbert, Edward

2012-01-01

397

EURRECA-Estimating iodine requirements for deriving dietary reference values.  

PubMed

Iodine is an essential component of thyroid hormones, and current recommendations for intake are based on urinary iodine excretion, assessment of thyroid size, thyroidal iodine accumulation and turnover, radioactive iodine uptake, balance studies, and epidemiological studies. Dietary iodine is rapidly and almost completely absorbed. The prevalence of inadequate iodine intake is high: 29% of the world's population lives in iodine-deficient areas and 44% of Europe remains mildly iodine deficient. To assess current data and update evidence for setting dietary recommendations for iodine, the EURRECA Network of Excellence has undertaken systematic review and evaluation of (i) the usefulness of iodine status biomarkers (ii) the relationship between iodine status biomarkers and dietary iodine intake, and (iii) the relationship between iodine intake and health outcomes (endemic goiter, hypothyroidism, and cognitive function). This review summarizes the main research outputs: the key findings of the literature review, results of the meta-analyses, and discussion of the main conclusions. Currently, data for relevant intake-status-health relationships for iodine are limited, particularly for population groups such as children under two years, pregnant women, and the elderly. The EURRECA Network developed best practice guidelines for the identification of pertinent iodine studies based on a systematic review approach. This approach aimed to identify comparable data, suitable for meta-analysis, for different countries and across all age ranges. When new data are available, the EURRECA Network best practice guidelines will provide a better understanding of iodine requirements for different health outcomes which could be used to set evidence-based dietary iodine recommendations for optimal health. PMID:23952087

Risti?-Medi?, Danijela; Novakovi?, Romana; Glibeti?, Maria; Gurinovi?, Mirjana

2013-01-01

398

Chamber studies of atmospheric iodine chemistry  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

399

Observations of iodine monoxide columns from satellite  

NASA Astrophysics Data System (ADS)

Iodine species in the troposphere are linked to ozone depletion and new particle formation. In this study, a full year of iodine monoxide (IO) columns retrieved from measurements of the SCIAMACHY satellite instrument is presented, coupled with a discussion of their uncertainties and the detection limits. The largest amounts of IO are found near springtime in the Antarctic. A seasonal variation of iodine monoxide in Antarctica is revealed with high values in springtime, slightly less IO in the summer period and again larger amounts in autumn. In winter, no elevated IO levels are found in the areas accessible to satellite measurements. This seasonal cycle is in good agreement with recent ground-based measurements in Antarctica. In the Arctic region, no elevated IO levels were found in the period analysed. This implies that different conditions with respect to iodine release exist in the two Polar Regions. To investigate possible release mechanisms, comparisons of IO columns with those of tropospheric BrO, and ice coverage are described and discussed. Some parallels and interesting differences between IO and BrO temporal and spatial distributions are identified. Overall, the large spatial coverage of satellite retrieved IO data and the availability of a long-term dataset provide new insight about the abundances and distributions of iodine compounds in the troposphere.

Schnhardt, A.; Richter, A.; Wittrock, F.; Kirk, H.; Oetjen, H.; Roscoe, H. K.; Burrows, J. P.

2008-02-01

400

Iodine - Its possible role in tropospheric photochemistry  

NASA Technical Reports Server (NTRS)

A detailed study of the photochemistry of iodine and its oxides indicates that iodine species may play an important role in the tropospheric photochemical system. Methyl iodide, often observed in the marine troposphere with an average concentration of 5-10 ppt, is photolyzed and thereby produces I atoms. Chemical interactions with O3, HxOy, and NOx cause I to be converted to other inorganic compounds such as IO, HOI, IONO2, and I2. The production of these species and their subsequent recycling back to I can lead to the catalytic removal of tropospheric O3, the enhancement of the NO2/NO ratio, the destruction of HxOy free radicals, and the conversion of HO2 to OH. Ultimately, tropospheric inorganic iodine is removed by heterogeneous processes. Calculations using a numerical model to simulate tropospheric photochemistry indicate that iodine may have a strong impact upon the atmospheric O3-NOx-HxOy system. The magnitude of these effects is dependent upon the value of several uncertain rate constants and the primary source distributions of CH3I and other organic and inorganic iodine compounds.

Chameides, W. L.; Davis, D. D.

1980-01-01

401

Iodine chemical forms in LWR severe accidents  

SciTech Connect

Calculated data from seven severe accident sequences in light-water reactor plants were used to assess the chemical forms of iodine in containment. In most of the calculations for the seven sequences, iodine entering containment from the reactor coolant system was almost entirely in the form of CsI with very small contributions of I or HI. The largest fraction of iodine in forms other than CsI was a total of 3.2% as I plus HI. Within the containment, the CsI will deposit onto walls and other surfaces, as well as in water pools, largely in the form of iodide (I{sup {minus}}). The radiation induced conversion of I{sup {minus}} in water pools into I{sub 2} is strongly dependent on pH. In systems where the pH was controlled above 7, little additional elemental iodine would be produced in the containment atmosphere. When the pH falls below 7, it may be assumed that it is not being controlled, and large fractions of iodine as I{sub 2} within the containment atmosphere may be produced. 16 refs.

Beahm, E.C.; Weber, C.F.; Kress, T.S.; Parker, G.W.

1991-01-01

402

Iodine isothermal migration behaviour in titanium nitride  

NASA Astrophysics Data System (ADS)

Titanium nitride is one of the inert matrixes proposed to surround the fuel in gas cooled fast reactor (GFR) systems. These reactors will operate at high temperature and refractory materials with a high chemical stability and good mechanical properties are required. Furthermore, a total retention of the most volatile fission products, such as I, Xe or Cs, by the inert matrix is needed during the in-pile process. The isothermal migration of iodine in TiN was studied by implanting 800 keV I ++ ions in sintered samples at an ion fluence of 5 10 15 cm -2. Thermal treatments were performed under secondary vacuum at temperatures ranging from 1200 to 1700 C. Iodine concentration profiles were determined by 2.5 MeV ?-particle elastic backscattering. The migration of iodine seems to be correlated with point defects created by implanted ions near the surface. The Arrhenius plot corresponding to iodine detrapping is curved with possibly two straight-line regions which could indicate either the presence of two types of traps, or a strong dependence of trap's concentration on temperature above 1500 C. The activation energies associated with each linear region of the Arrhenius plot were found to be: Ea = 2.4 0.2 eV below 1500 C and E=11.40.2 eV above 1500 C. Nitrogen evaporation from TiN surface under secondary vacuum was proposed as a contributing factor to the enhanced mobility of iodine at high temperature.

Gavarini, S.; Jaffrezic, H.; Martin, P.; Peaucelle, C.; Toulhoat, N.; Cardinal, S.; Moncoffre, N.; Pichon, C.; Tribet, M.

2008-02-01

403

Iodination of organic compounds via organoborane intermediates: new methods  

SciTech Connect

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.

Gooch, E.E. III

1981-01-01

404

Effect of iodine disinfection products on higher plants  

NASA Astrophysics Data System (ADS)

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.

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

405

History of endemic goiter in Croatia: from severe iodine deficiency to iodine sufficiency.  

PubMed

At the time after the Second World War, endemic goiter was present in most parts of Croatia with a prevalence of more than 50% and presence of cretinism. In the village of Rude near Zagreb, goiter was detected in 85% of school children with 2.3% of cretins in the village population. In 1953 the first regulation on obligatory salt iodination, requiring 10 mg of potassium iodide (KI) per kg of salt was established in former Yugoslavia. A three-fold reduction of goiter prevalence, together with disappearance of cretinism was recorded ten years later In 1992, the National Committee for Eradication of Goiter was founded. The survey performed during 1991-1993 exhibited prevalence of goiter among school children between 8% and 35% and urinary iodine excretion under 10 microg/dL in most of the children from continental parts of the country. The new obligatory regulation, requiring 25 mg of KI/kg of salt, was proposed by the National Comittee and finally established in 1996. In 2002 thyroid volumes and medians of urinary iodine excretion were normal according to the ICCIDD criteria. Overall median of urinary iodine excretion for schoolchildren in Croatia was 14 ug/dL. Croatia crossed a path from severe iodine deficiency detected in the 1950's to the period of mild to moderate iodine deficiency during the 1990's, and finally, nowadays, iodine sufficiency has been achieved. PMID:16117293

Kusi?, Zvonko; Juki?, Tomislav

2005-06-01

406

Theoretical studies of lasers and converters  

NASA Technical Reports Server (NTRS)

Discussed here is Doppler broadening and its effects upon the stimulated emission cross-section connecting an upper level with a lower level in an iodine laser. The stimulated emission cross section is given. The level transitions for the iodine laser are illustrated as are the relative intensities of these transitions. Also discussed is the Voigt profile, which considers the effect of both Doppler broadening and collision broadening upon the absorption line shape. The equations describing the Voigt profile were added to the continuous flow laser model laser simulation program. The results were compared with the standard absorption profile reported in an earlier study. There seems to be no advantage to using the Voigt profile as the laser power output is relatively insensitive to changes in the absorption cross section at the pressures being considered for a space laser. One disadvantage of using the Voigt profile is the excessive numerical computations required by the additional equations.

Heinbockel, John H.

1991-01-01

407

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

SciTech Connect

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)

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

2013-07-31

408

Highly adhesive metal plating on Zylon fiber via iodine pretreatment  

Microsoft Academic Search

Highly adhesive metal plating was performed on poly(p-phenylene-2,6-benzobisoxazole) fiber named Zylon via iodine pretreatment followed by electroless plating. First, iodine components were selectively doped into the inner part of the fiber near the surface through iodine vapor exposure. The doped iodine was converted to palladium iodide particles by treating with palladium chloride solution. After the reduction of the iodide to

Ummul Khair Fatema; Yasuo Gotoh

2011-01-01

409

Behaviour of iodine in the terrestrial environment. An investigation of the possible enzymatically controlled iodination of humic acid.  

National Technical Information Service (NTIS)

Literature on the geochemistry of iodine is surveyed, focusing on fundamental chemical aspects which influence the migration behaviour of iodine in the terrestrial environment. It is stated that the organic fraction in soil plays the predominant role in t...

J. V. Christiansen

1990-01-01

410

COMPARISON OF IODINE131 METABOLISM IN DIFFERENT STRAINS OF MICE  

Microsoft Academic Search

Thyroidal iodine metabolism was studied in four strains of mice by use ; of I¹³¹. Strain differences were found for iodine uptake, release rate ; from thyroid, and conversion raXio. Seasonal differences of iodine uptake were ; found in all strains. There was no apparent relationship between aii strains. ; There was no apparent relationship between these three parameters of

T. Tsuchiya; J. Hayakawa; T. Sugahara

1962-01-01

411

Regenerable Iodine Water-Disinfection System  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

412

Oxygen centered radicals in iodine chemical oscillators.  

PubMed

The existence of free radicals in iodine-based oscillatory systems has been debated for some time. Recently, we have reported the presence of reactive oxygen species (ROS) in the iodide-peroxide system in acidic medium, which is common to all iodine--based oscillatory systems ( J. Phys. Chem. A 2011 , 115 , 2247--2249 ). In this work, the goal was to identify the ROS produced in this system using an EPR spin trap which can distinguish between hydroxyl (HO()) and hydroperoxyl (HOO()) radicals. The formation of the hydroperoxyl radical was observed and a possible explanation for the low EPR signal of hydroxyl radical was proposed. PMID:21692499

Stanisavljev, Dragomir R; Milenkovi?, Maja C; Mojovi?, Milos D; Popovi?-Bijeli?, Ana D

2011-07-14

413

Hydrolysis of iodine: equilibria at high temperatures  

SciTech Connect

The hydrolysis (or disproportionation) of molecular iodine to form iodate and iodide ions has been studied by emf measurements over the temperature range, 3.8/sup 0/ to 209.0/sup 0/C. The interpretation of these results required a knowledge of the formation constant for triiodide ion and the acid dissociation constant of iodic acid, both of which were measured as a function of temperature. The resulting thermodynamic data have been incorporated into a general computer model describing the hydrolysis equilibria of iodine as a function of initial concentration, pH and temperature.

Palmer, D.A.; Ramette, R.W.; Mesmer, R.E.

1984-01-01

414

Facile Oxidative Rearrangements Using Hypervalent Iodine Reagents  

PubMed Central

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.

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

2012-01-01

415

Effect of Vaginal Douching with PovidoneIodine during Early Pregnancy on the Iodine Supply to Mother and Fetus  

Microsoft Academic Search

Vaginal douching with polyvinylpyrrolidone iodine (PVP-I) during pregnancy results in maternal iodine overload and increases the iodine content of amniotic fluid. We evaluated the possible effects of this therapy on the thyroid of the fetus by investigating 62 women with a mean duration of amenorrhea of 20 weeks who solicited controlled abortion. Nineteen of them douched daily with PVP-I for

J. Mahillon; W. Peers; P. Bourdoux; A. M. Ermans; F. Delangeb

1989-01-01

416

Multiple-photon laser-induced fluorescence. [HS and DS radicals  

SciTech Connect

The technique of multiple-photon laser-induced fluorescence has been used to study the spectroscopy and dynamics of atoms, molecules, and free radicals. Among the species investigated were iodine atoms (I), carbon monoxide (CO), molecular iodine (I/sub 2/), and HS and DS radicals. 7 figures.

Tiee, J.J.; Ferris, M.J.; Loge, G.W.; Wampler, F.B.; Hartford, A.

1982-01-01

417

An iodine mass-balance for Lake Constance, Germany: Insights into iodine speciation changes and fluxes  

NASA Astrophysics Data System (ADS)

Lake Constance is one of Europe's largest oligotrophic lakes and provides a water source for more than 4.5 million people in Germany and Switzerland. We present here a 12 month study on iodine concentrations, speciation and fluxes to and from the lake to gain a quantitative understanding of the limnic iodine cycle. Monthly water samples were obtained from all major tributaries (14) and the outflow to construct a mass-balance model. Sediment traps were also deployed in the lake for two years at two different stations. Total soluble iodine (TSI) in aqueous samples were analysed by ICP-MS and speciation (iodide, iodate and soluble organically bound iodine, SOI) by ion chromatography-ICP-MS. Iodine concentrations in the Alpine tributaries (1-2 ?g l -1) decreased over the summer months due to increasing proportions of snow and glacial melt water from the Alps, while iodine levels in the lowland rivers (2-10 ?g l -1) increased over the summer. Deposition of TSI to the catchment (16,340 kg I yr -1) was similar to the TSI out-flux by rivers (16,000 kg I yr -1). By also including the particulate riverine iodine flux out of the catchment (12,350 kg I yr -1) it is shown that the catchment is a net source of iodine, with the highest particulate fluxes coming from the Alpine rivers. The total TSI flux to the lake was 16,770 kg I yr -1, the largest proportion coming from the Alpenrhein (43%), followed by the Schussen (8%) and Bregenzer Ach (7.7%). Overall the mass-balance for TSI in the lake was negative, with more iodine flowing out of the lake than in (-2050 kg I yr -1; 12% of TSI in-flux). To maintain mass-balance, 8.8 ?g I m -2 d -1 from the Obersee and 23 ?g I m -2 d -1 from the Untersee must be released from the sediments into the water column. Thus, in comparison with the total iodine flux to the sediments measured by the sediment traps (4762-8075 kg I yr -1), up to 39% of the deposited iodine may be mobilised back into the lake. SOI was the dominant iodine fraction entering the lake, with a total flux of 10,290 kg I yr -1 (64% of TSI input), followed by iodate (3120 kg I yr -1) and iodide (2760 kg I yr -1). Net formation of SOI from iodide and iodate was also noted within the lake, with an estimated production of 6560 kg I yr -1, suggesting a strong role for biology in iodine cycling. In conclusion, organically bound iodine was the dominant iodine species in aqueous and solid phases in Lake Constance, despite low DOC concentrations (<2 mg l -1), and thus is expected to play an important role in iodine cycling in most freshwater environments.

Gilfedder, B. S.; Petri, M.; Wessels, M.; Biester, H.

2010-06-01

418

Preparation of Iodine-125 - Labeled Insulin for Radioimmunoassay: Comparison of Chloramine T and Iodogen Iodination.  

National Technical Information Service (NTIS)

Stoichiometric iodination of porcine insulin was performed to the general method of Hunter and Greenwood with modifications recommended by Roth. These method was compared with radioidination using Iodogen. Films of Iodogen react rapidly in the solid phase...

I. T. Toledo e Souza D. Giannella Neto B. L. Wajchenberg

1988-01-01

419

Source And Sink Of Iodine For Drinking Water  

NASA Technical Reports Server (NTRS)

Proposed system for controlling concentration of iodine in potable water exploits temperature dependence of equilibrium partition of iodine between solution in water and residence in ion-exchange resin. Used to maintain concentration of iodine sufficient to kill harmful microbes, but not so great to make water unpalatable. Requires little attention, yet controls concentration of iodine more precisely than iodination and deiodination by manual techniques. Conceived for use aboard spacecraft, system has terrestrial applications in regions where water must be kept potable, resupply difficult, and system must operate largely unattended.

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

1991-01-01

420

Micromethod for the Rapid Determination of Serum Protein-Bound Iodine and Total Serum Iodine  

Microsoft Academic Search

A modification is presentedof the chloric acid method for the rapid determination of serum protein-bound iodine and total serum iodine requiring less than 0.5 ml. serum for duplicate determinations. The time required for the entire procedure is lessthan two hours. Byadjusting the amountsof reagents used and by varying the time of digestion, the need for constant and continuoussupervisionis eliminated. 'IE1HEDETERMINATION

Eli Gardiner; Arthur Bums

421

ASSESSMENT OF IODINE NUTRITION STATUS AMONG SCHOOL AGE CHILDREN OF NEPAL BY URINARY IODINE ASSAY  

Microsoft Academic Search

The present study was undertaken to evaluate the iodine status of Nepalese school age children by measuring urinary iodine excretion (UIE). A population based cross-sectional study was conducted during November-December 2006 among 1,094 school age children. Spot urine samples were collected from all children and UIE was measured during February to March 2007 by an ammonium persulfate digestion microplate (APDM)

B Gelal; M Aryal; BK Lal Das; B Bhatta; M Lamsal; N Baral

2009-01-01

422

Iodine status in pregnant women and their newborns: are our babies at risk of iodine deficiency?  

Microsoft Academic Search

Objectives: To determine whether pregnant women and their newborns show evidence of iodine deficiency, and to examine the correlation between maternal urine iodine concentration (UIC) and newborn thyroid-stimulating hormone (TSH) level. Design: A cross-sectional study. Setting: Hospital antenatal care services (March-May 2004) and private obstetrician clinics (June 2004) in the Central Coast area of New South Wales. Participants: 815 pregnant

Cheryl A Travers; Kamala Guttikonda; Carol A Norton; Peter R Lewis; Lyndall J Mollart; Bridget Wilcken; Creswell J Eastman; Steven C Boyages

2006-01-01

423

Iodine insufficiency: a global health problem?  

PubMed

As a result of collaborative efforts with international organizations and the salt industry, many developing and developed countries practice universal salt iodization (USI) or have mandatory salt fortification programs. As a consequence, the prevalence of iodine deficiency decreased dramatically. The United States and Canada are among the few developed countries that do not practice USI. Such an undertaking would require evidence of deficiency among vulnerable population groups, including pregnant women, newborns, and developing infants. Government agencies in the United States rely heavily on data from NHANES to assess the iodine status of the general population and pregnant women in particular. NHANES data suggest that pregnant women in the United States remain mildly deficient. This is important, because the developing fetus is dependent on maternal iodine intake for normal brain development throughout pregnancy. Professional societies have recommended that pregnant and lactating women, or those considering pregnancy, consume a supplement providing 150 ?g iodine daily. The United States and Canada collaborate on the daily recommended intake and are also confronted with the challenge of identifying the studies needed to determine if USI is likely to be beneficial to vulnerable population groups without exposing them to harm. PMID:24038248

Swanson, Christine A; Pearce, Elizabeth N

2013-01-01

424

Microwave harmonic mixing in iodine doped polyacetylene  

NASA Astrophysics Data System (ADS)

Measurements of the temperature dependence of the conductivity and of the microwave harmonic mixing (MHM) signal produced by the non-ohmic behavior of iodine doped polyacetylene in the metallic regime are reported. The experimental results are consistent with fluctuation induced tunneling conduction between fibers. The theory has been adapted for low electric field strengths and microwave frequencies.

Mayr, W.; Philipp, A.; Seeger, K.

1982-07-01

425

Effect of povidone iodine on thyroid functions and urine iodine levels in caesarean operations.  

PubMed

Abstract Objective: In the present study, the effects of povidone iodine (PI) used during Caesarean operations on maternal thyroid hormones and urine iodine levels in the infant and the mother were investigated. Design: Twenty-seven patients were allocated to the PI group I (Gr I), and 28 to the non-PI group (Group II). Maternal preoperative and 24th-h postoperative free T3 (fT3), freeT4 (fT4), TSH, and urine iodine levels were determined, as well as infant urine iodine values. Results: In both groups, fT3 levels before and after the operation were found to be reduced (p?iodine levels of the mothers increased 25% in Gr I, but only 2% in Gr II. Conclusions: The absorption of PI by the skin was found to lead to changes in fT3, TSH, and urine iodine excretion values in the mothers. The findings of this study of Caesarean operations, which have a short duration, might be a signal to be careful of thyroid hormone effects in operations lasting longer. PMID:24060143

Findik, Rahime Bedir; Yilmaz, Gulsen; Celik, Huseyin Tugrul; Yilmaz, Fatma Meric; Hamurcu, Ugur; Karakaya, Jale

2014-07-01

426

Determination of iodide, iodate and organo-iodine in waters with a new total organic iodine measurement approach.  

PubMed

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

Gong, Tingting; Zhang, Xiangru

2013-11-01

427

Clinical and biological consequences of iodine deficiency during pregnancy.  

PubMed

The main change in thyroid function associated with the pregnant state is the requirement of an increased production of thyroid hormone that depends directly upon the adequate availability of dietary iodine and integrity of the glandular machinery. In healthy pregnant women, physiological adaptation takes place when the iodine intake is adequate, while this is replaced by pathological alterations when there is a deficient iodine intake. Pregnancy acts typically, therefore, as a revelator of underlying iodine restriction. Iodine deficiency has important repercussions for both the mother and the fetus, leading to hypothyroxinemia, sustained glandular stimulation and finally goitrogenesis. Furthermore, because severe iodine deficiency may be associated with an impairment in the psychoneurointellectual outcome in the progeny, because both mother and offspring are exposed to iodine deficiency during gestation (and the postnatal period), and because iodine deficiency is still prevalent today in several large regions of the world, iodine supplements should be given systematically to pregnant and breastfeeding mothers. Particular attention is required to ensure that pregnant women receive an adequate iodine supply, in order to reach the ideal recommended nutrient intake of 250 microg iodine/day. PMID:17684390

Glinoer, Daniel

2007-01-01

428

A rate equation approach to gain saturation effects in laser mode calculations  

NASA Technical Reports Server (NTRS)

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.

Roberts, Lila F.

1990-01-01

429

The challenges of iodine supplementation: a public health programme perspective.  

PubMed

An adequate iodine intake during pregnancy, lactation and early childhood is particularly critical for optimal brain development of the foetus and of children 7-24 months of age. While the primary strategy for sustainable elimination of iodine deficiency remains universal salt iodisation, the World Health Organization and the United Nations Children's Fund recommend a complementary strategy of iodine supplements as a temporary measure when salt iodisation could not be implemented. This article aims to review current evidence on efficacy and implications of implementing iodine supplementation as a public health measure to address iodine deficiency. Iodine supplementation seems unlikely to reach high coverage in a rapid, equitable and sustained way. Implementing the programme requires political commitment, effective and efficient supply, distribution and targeting, continuous education and communication and a robust monitoring system. Thus, universal salt iodisation should remain the primary strategy to eliminate iodine deficiency. PMID:20172473

Untoro, Juliawati; Timmer, Arnold; Schultink, Werner

2010-02-01

430

Additional studies for the spectrophotometric measurement of iodine in water  

NASA Technical Reports Server (NTRS)

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.

1972-01-01

431

Metabolic engineering of the iodine content in Arabidopsis  

PubMed Central

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.

Landini, Martina; Gonzali, Silvia; Kiferle, Claudia; Tonacchera, Massimo; Agretti, Patrizia; Dimida, Antonio; Vitti, Paolo; Alpi, Amedeo; Pinchera, Aldo; Perata, Pierdomenico

2012-01-01

432

Influence of dietary iodine on the iodine content of pork and the distribution of the trace element in the body  

Microsoft Academic Search

BackgroundMillions of people worldwide still suffer from iodine deficiency disorders. Besides salt iodination, iodine is added to animal\\u000a feed to concentrate it in food of animal origin (milk, eggs, meat). Otherwise possible adverse effects of high supplementation\\u000a should be avoided.\\u000a \\u000a \\u000a \\u000a Aim of the studyThe objective of the study was to evaluate the iodine content of pork at various feed iodine

Katrin Franke; Friedrich Schne; Andreas Berk; Matthias Leiterer; Gerhard Flachowsky

2008-01-01

433

Iodine Revolatilization in a Grand Gulf Loca  

SciTech Connect

The TRENDS models are applied at each time step to each control volume. Significant amounts of water occur only in the wetwell and drywell sump (the refueling pool is not a factor, as discussed earlier). In Fig. 2, we show the radiolytic acid production feeding into each of these pools. Since the water is initially neutral and no chemical additives are present, the acid additions are the major factors affecting pH. In Fig. 3, we see the downward trend of pH resulting from these acid additions. The conversion of iodide (I{sup {minus}}) to molecular iodine (I{sub 2}) is most noticeable in the wetwell, since this is the repository of most iodide and HCl. Gradually, during the transient small amounts of more volatile iodine are formed. While iodide remains the dominant form, noticeable amounts of I{sub 2} and intermediate species are created. Once produced in water, some I{sub 2} is free to evaporate into airspace. Fig. 4 indicates the increase in all airborne iodine throughout the transient. This is compared to the MELCOR result for CsI aerosol, which decreases dramatically due to containment sprays. The I{sub 2} in the airspace can be vented to the enclosure building or the environment. In the present accident sequence, the only path to the environment was through the SGTS, which was assumed to operate as in MELCOR. However, both are dwarfed by the MELCOR gaseous release during the first 12 h because MELCOR does not model spray washout of gaseous iodine. Steadily increasing throughout the transient, the revolatilization release is eventually more than an order-or-magnitude higher than the MELCOR aerosol release. Also, 99% of iodine flowing directly through the SGTS was retained in filters. The remaining 1% was released to the environment. In addition, a small flow bypassing the SGTS filters vented directly into the environment. The total released from these two paths is shown in Fig. 5.

Beahm, E.C.; Weber, C.F.

1999-01-01

434

Long-term migration of iodine in sedimentary rocks based on iodine speciation and 129I/127I ratio  

NASA Astrophysics Data System (ADS)

[Introduction] 129I is one of the available indexes of long-term migration of groundwater solutes, because of its long half-life (15.7 million years) and low sorption characteristics. The Horonobe underground research center (Japan Atomic Energy Agency), at which are conducted research and development of fundamental techniques on geological disposal of high-level radioactive waste, is an appropriate site for natural analogue studies, because iodine concentration in groundwater is high in this area. To predict iodine behavior in natural systems, speciation of iodine is essential because of different mobility among each species. In this study, we determined iodine speciation and129I/127I isotope ratios of rock and groundwater samples to investigate long term migration of iodine. [Methods] All rock and groundwater samples were collected at Horonobe underground research center. The region is underlain mainly by Neogene to Quaternary marine sedimentary rocks, the Wakkanai Formation (Wk Fm, siliceous mudstones), and the overlying Koetoi Formation (Kt Fm, diatomaceous mudstones). Iodine species in rock samples were determined by iodine K-edge X-ray absorption near edge structure (SPring-8 BL01B1). Thin sections of rock samples were prepared, and iodine mapping were obtained by micro-XRF analysis (SPring-8 BL37XU). Iodine species (IO3-, I-, and organic I) in groundwater were separately detected by high performance liquid chromatography connected to ICP-MS. The 129I/127I ratios in groundwater and rock samples were measured by accelerator mass spectrometry (MALT, Univ. of Tokyo). Iodine in rock samples were separated by pyrohydrolysis and water extraction. [Results and discussion] Concentration of iodine in groundwater varied widely and was much higher than that of seawater showing a high correlation with that of chlorine (R2 = 0.90). Species of iodine in groundwater was mainly I-. Iodine in rock samples decreased near the boundary between Wk and Kt Fms. Iodine K-edge XANES showed that iodine in rock was a mixture of organic and inorganic iodine. According to iodine and carbon mapping in micrometer scale, iodine was accumulated locally and correlated with carbon, suggesting that iodine existed as organic iodine. The 129I/127I isotope ratios in groundwater were lower than those in rocks and almost constant at various depths, demonstrating that iodine in groundwater was released from layers deeper than co-existing rocks. According to these results, migration of iodine in this area can be expected as follows. (i) During sedimentation of Wk and Kt Fms, iodine was accumulated as organic iodine in siliceous sediments. (ii) Iodine was released as I- from the layers deeper than Wk Fm during diagenetic processes. Subsequently, iodine rich groundwater was distributed to Wk and Kt Fms due to the compaction of the layers. (iii) During uplift and denudation processes, both iodine and chlorine were diluted by meteoric water from the surface. Iodine distribution coefficient (Kd = [I concentration in rock]/[I concentration in groundwater]) of Kt Fm is higher than that in Wk Fm. Diatomaceous mudstones might be more effective than siliceous mudstones as natural barrier for 129I released from deep underground radioactive waste repository. This suggestion should be reinforced by laboratory experiments in future studies.

Togo, Y.; Takahashi, Y.; Amano, Y.; Matsuzaki, H.; Suzuki, Y.; Muramatsu, Y.; Iwatsuki, T.

2012-12-01

435

Efficient flashlamp-pumped IBr laser  

NASA Technical Reports Server (NTRS)

The operating characteristics and scaling parameters of a flashlamp-pumped, 4-m-long IBr laser were investigated to further evaluate its potential as a solar-pumped laser. A peak power of 3 kW/sq cm at 2.7 microns was achieved at 4-Torr IBr pressure. A gain of 0.07 per m was measured at a maximum capacitor discharge energy of 4 kJ. The threshold input power necessary for lasing was found to decrease by a factor of 4 and the laser pulse width increased fourfold as the active gain length was increased from 1 to 4 m. A maximum pulse width of 120 microseconds was achieved with 10-Torr argon diluent added to 4-Torr IBr. Quenching of the excited state by the parent molecule was shown to be unimportant for pressures less than 4-Torr IBr. An intrinsic efficiency in the range of 12 percent has been measured for flashlamp-pumped IBr.

Zapata, L. E.; De Young, R. J.

1985-01-01

436

Reaction of gaseous mercury with molecular iodine, atomic iodine, and iodine oxide radicals - Kinetics, product studies, and atmospheric implications  

NASA Astrophysics Data System (ADS)

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.

Raofie, F.; Snider, G.; Ariya, P.

2008-12-01

437

Compact cw supersonic chemical oxygen-iodine laser (COIL)  

NASA Astrophysics Data System (ADS)

A closed-loop flowing basic hydrogen peroxide (BHP) system with real-time cooling was constructed and coupled to a supersonic COIL, resulting in a 20-min. continuous run at an average power of 500 W. An overall BHP heat transfer coefficient of 150 BTU/(hr(DOT)ft2(DOT) degree(s)F) was measured.

Phipps, Steven P.; Helms, Charles A.; Truesdell, Keith A.; Healey, Keith P.

1995-03-01

438

Iodine stress corrosion cracking of Zircaloy reactor cladding: iodine chemistry (a review)  

NASA Astrophysics Data System (ADS)

This review covers chemical aspects of the iodine stress corrosion cracking (ISCC) pellet-cladding interaction (PCI) failures which have occurred in some reactors with UO 2 fuel in unlined Zircaloy tubes. The cracking mechanism is discussed in relation to chemical factors. Cesium and iodine are released as fission products and form CsI but its dissociation iodine pressure p(I) is many orders of magnitude greater than chemical thermodynamic calculations predict, due to radiolysis. This enhanced p(I) can form ZrI 4 in regions where Zr is exposed (not protected by surface scale) and a van Arkel vapour transport reaction then causes rapid Zr transport from localised cladding areas, i.e. pitting, which later becomes a crack site. Requirements are a critical strain rate (which cracks protective scale), iodine pressure and time, i.e. a power ramp. Factors include that a stress caused by a power ramp may relax before the required gap chemistry is achieved and that a ramp also releases short-lived I and Cs fission products which add to the iodine pressure available.

Sidky, P. S.

1998-07-01

439

The impact of iodine supplementation and bread fortification on urinary iodine concentrations in a mildly iodine deficient population of pregnant women in South Australia.  

PubMed

Mild iodine deficiency during pregnancy can have significant effects on fetal development and future cognitive function. The purpose of this study was to characterise the iodine status of South Australian women during pregnancy and relate it to the use of iodine-containing multivitamins. The impact of fortification of bread with iodized salt was also assessed. Women (n?=?196) were recruited prospectively at the beginning of pregnancy and urine collected at 12, 18, 30, 36 weeks gestation and 6 months postpartum. The use of a multivitamin supplement was recorded at each visit. Spot urinary iodine concentrations (UIC) were assessed. Median UICs were within the mildly deficient range in women not taking supplements (<90 ?g/L). Among the women taking iodine-containing multivitamins UICs were within WHO recommendations (150-249 ?g/L) for sufficiency and showed an increasing trend through gestation. The fortification of bread with iodized salt increased the median UIC from 68 ?g/L to 84 ?g/L (p?=?.011) which was still in the deficient range. Pregnant women in this region of Australia were unlikely to reach recommended iodine levels without an iodine supplement, even after the mandatory iodine supplementation of bread was instituted in October 2009. PMID:23497409

Clifton, Vicki L; Hodyl, Nicolette A; Fogarty, Paul A; Torpy, David J; Roberts, Rachel; Nettelbeck, Ted; Ma, Gary; Hetzel, Basil

2013-01-01

440

The impact of iodine supplementation and bread fortification on urinary iodine concentrations in a mildly iodine deficient population of pregnant women in South Australia  

PubMed Central

Mild iodine deficiency during pregnancy can have significant effects on fetal development and future cognitive function. The purpose of this study was to characterise the iodine status of South Australian women during pregnancy and relate it to the use of iodine-containing multivitamins. The impact of fortification of bread with iodized salt was also assessed. Women (n?=?196) were recruited prospectively at the beginning of pregnancy and urine collected at 12, 18, 30, 36weeks gestation and 6months postpartum. The use of a multivitamin supplement was recorded at each visit. Spot urinary iodine concentrations (UIC) were assessed. Median UICs were within the mildly deficient range in women not taking supplements (<90?g/L). Among the women taking iodine-containing multivitamins UICs were within WHO recommendations (150249?g/L) for sufficiency and showed an increasing trend through gestation. The fortification of bread with iodized salt increased the median UIC from 68?g/L to 84?g/L (p?=?.011) which was still in the deficient range. Pregnant women in this region of Australia were unlikely to reach recommended iodine levels without an iodine supplement, even after the mandatory iodine supplementation of bread was instituted in October 2009.

2013-01-01

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