Sample records for atomic vapor laser

  1. Atomic-vapor-laser isotope separation

    SciTech Connect (OSTI)

    Davis, J.I.

    1982-10-01T23:59:59.000Z

    This paper gives a brief history of the scientific considerations leading to the development of laser isotope separation (LIS) processes. The close relationship of LIS to the broader field of laser-induced chemical processes is evaluated in terms of physical criteria to achieve an efficient production process. Atomic-vapor LIS processes under development at Livermore are reviwed. 8 figures.

  2. Atomic vapor laser isotope separation of lead-210 isotope

    DOE Patents [OSTI]

    Scheibner, K.F.; Haynam, C.A.; Johnson, M.A.; Worden, E.F.

    1999-08-31T23:59:59.000Z

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207. 5 figs.

  3. Atomic vapor laser isotope separation of lead-210 isotope

    DOE Patents [OSTI]

    Scheibner, Karl F. (Tracy, CA); Haynam, Christopher A. (Pleasanton, CA); Johnson, Michael A. (Pleasanton, CA); Worden, Earl F. (Diablo, CA)

    1999-01-01T23:59:59.000Z

    An isotopically selective laser process and apparatus for removal of Pb-210 from natural lead that involves a one-photon near-resonant, two-photon resonant excitation of one or more Rydberg levels, followed by field ionization and then electrostatic extraction. The wavelength to the near-resonant intermediate state is counter propagated with respect to the second wavelength required to populate the final Rydberg state. This scheme takes advantage of the large first excited state cross section, and only modest laser fluences are required. The non-resonant process helps to avoid two problems: first, stimulated Raman Gain due to the nearby F=3/2 hyperfine component of Pb-207 and, second, direct absorption of the first transition process light by Pb-207.

  4. Coherent Control of Laser Field and Spectroscopy in Dense Atomic Vapor

    E-Print Network [OSTI]

    Li, Hebin

    2011-08-08T23:59:59.000Z

    not be achieved in optical domain. Based on this system, experiments can be conducted to simulate processes in ultra-short laser physics. In particular, we study the carrier-envelope effect of few-cycle pulses and the strong off-resonant excitation by short pulses...

  5. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Paducah Gaseous Diffusion Plant site

    SciTech Connect (OSTI)

    Marmer, G.J.; Dunn, C.P.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Yuen, C.R.; Cleland, J.H. (ed.)

    1991-09-01T23:59:59.000Z

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. The U-235 atoms are ionized when precisely tuned laser light -- of appropriate power, spectral, and temporal characteristics -- illuminates the uranium vapor and selectively photoionizes the U-235 isotope. A programmatic document for use in screening DOE site to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the PGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. 65 refs., 15 tabs.

  6. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Oak Ridge Gaseous Diffusion Plant Site

    SciTech Connect (OSTI)

    Not Available

    1991-09-01T23:59:59.000Z

    In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) technology, with the near-term goal to provide the necessary information to make a deployment decision by November 1992. The U-AVLIS process is based on electrostatic extraction of photoionized U-235 atoms from an atomic vapor stream created by electron-beam vaporization of uranium metal alloy. A programmatic document for use in screening DOE sites to locate the U-AVLIS production plant was developed and implemented in two parts (Wolsko et al. 1991). The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. These sites were then subjected to a more rigorous and detailed comparative analysis for the purpose of developing a short list of reasonable alternative sites for later environmental examination. This environmental site description (ESD) provides a detailed description of the ORGDP site and vicinity suitable for use in an environmental impact statement (EIS). The report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during a site visit. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use, socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3. Following the site description and additional data requirements, Sec. 4 provides a short, qualitative assessment of potential environmental issues. 37 refs., 20 figs., 18 tabs.

  7. Wick for metal vapor laser

    DOE Patents [OSTI]

    Duncan, David B. (Livermore, CA)

    1992-01-01T23:59:59.000Z

    An improved wick for a metal vapor laser is made of a refractory metal cylinder, preferably molybdenum or tungsten for a copper laser, which provides the wicking surface. Alternately, the inside surface of the ceramic laser tube can be metalized to form the wicking surface. Capillary action is enhanced by using wire screen, porous foam metal, or grooved surfaces. Graphite or carbon, in the form of chunks, strips, fibers or particles, is placed on the inside surface of the wick to reduce water, reduce metal oxides and form metal carbides.

  8. Coupling apparatus for a metal vapor laser

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Miller, John L. (Dublin, CA)

    1993-01-01T23:59:59.000Z

    Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

  9. Coupling apparatus for a metal vapor laser

    DOE Patents [OSTI]

    Ball, D.G.; Miller, J.L.

    1993-02-23T23:59:59.000Z

    Coupling apparatus for a large bore metal vapor laser is disclosed. The coupling apparatus provides for coupling high voltage pulses (approximately 40 KV) to a metal vapor laser with a high repetition rate (approximately 5 KHz). The coupling apparatus utilizes existing thyratron circuits and provides suitable power input to a large bore metal vapor laser while maintaining satisfactory operating lifetimes for the existing thyratron circuits.

  10. Atomic vapor spectroscopy in integrated photonic structures

    E-Print Network [OSTI]

    Ritter, Ralf; Pernice, Wolfram; Kübler, Harald; Pfau, Tilman; Löw, Robert

    2015-01-01T23:59:59.000Z

    We investigate an integrated optical chip immersed in atomic vapor providing several waveguide geometries for spectroscopy applications. The narrow-band transmission through a silicon nitride waveguide and interferometer is altered when the guided light is coupled to a vapor of rubidium atoms via the evanescent tail of the waveguide mode. We use grating couplers to couple between the waveguide mode and the radiating wave, which allow for addressing arbitrary coupling positions on the chip surface. The evanescent atom-light interaction can be numerically simulated and shows excellent agreement with our experimental data. This work demonstrates a next step towards miniaturization and integration of alkali atom spectroscopy and provides a platform for further fundamental studies of complex waveguide structures.

  11. Environmental site description for a Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) production plant at the Portsmouth Gaseous Diffusion Plant site

    SciTech Connect (OSTI)

    Marmer, G.J.; Dunn, C.P.; Filley, T.H.; Moeller, K.L.; Pfingston, J.M.; Policastro, A.J.; Cleland, J.H.

    1991-09-01T23:59:59.000Z

    Uranium enrichment in the United States has utilized a diffusion process to preferentially enrich the U-235 isotope in the uranium product. In the 1970s, the US Department of Energy (DOE) began investigating more efficient and cost-effective enrichment technologies. In January 1990, the Secretary of Energy approved a plan for the demonstration and deployment of the Uranium Atomic Vapor Laser isotope Separation (U-AVLIS) technology with the near-term goal to provide the necessary information to make a deployment decision by November 1992. Initial facility operation is anticipated for 1999. A programmatic document for use in screening DOE sites to locate a U-AVLIS production plant was developed and implemented in two parts. The first part consisted of a series of screening analyses, based on exclusionary and other criteria, that identified a reasonable number of candidate sites. The final evaluation, which included sensitivity studies, identified the Oak Ridge Gaseous Diffusion Plant (ORGDP) site, the Paducah Gaseous Diffusion Plant (PGDP) site, and the Portsmouth Gaseous Diffusion Plant (PORTS) site as having significant advantages over the other sites considered. This environmental site description (ESD) provides a detailed description of the PORTS site and vicinity suitable for use in an environmental impact statement (EIS). This report is based on existing literature, data collected at the site, and information collected by Argonne National Laboratory (ANL) staff during site visits. The organization of the ESD is as follows. Topics addressed in Sec. 2 include a general site description and the disciplines of geology, water resources, biotic resources, air resources, noise, cultural resources, land use. Socioeconomics, and waste management. Identification of any additional data that would be required for an EIS is presented in Sec. 3.

  12. Diode pumped alkali vapor fiber laser

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

    2007-10-23T23:59:59.000Z

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  13. Diode pumped alkali vapor fiber laser

    DOE Patents [OSTI]

    Payne, Stephen A. (Castro Valley, CA); Beach, Raymond J. (Livermore, CA); Dawson, Jay W. (Livermore, CA); Krupke, William F. (Pleasanton, CA)

    2006-07-26T23:59:59.000Z

    A method and apparatus is provided for producing near-diffraction-limited laser light, or amplifying near-diffraction-limited light, in diode pumped alkali vapor photonic-band-gap fiber lasers or amplifiers. Laser light is both substantially generated and propagated in an alkali gas instead of a solid, allowing the nonlinear and damage limitations of conventional solid core fibers to be circumvented. Alkali vapor is introduced into the center hole of a photonic-band-gap fiber, which can then be pumped with light from a pump laser and operated as an oscillator with a seed beam, or can be configured as an amplifier.

  14. Copper vapor laser acoustic thermometry system

    DOE Patents [OSTI]

    Galkowski, Joseph J. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    A copper vapor laser (CVL) acoustic thermometry system is disclosed. The invention couples an acoustic pulse a predetermined distance into a laser tube by means of a transducer and an alumina rod such that an echo pulse is returned along the alumina rod to the point of entry. The time differential between the point of entry of the acoustic pulse into the laser tube and the exit of the echo pulse is related to the temperature at the predetermined distance within the laser tube. This information is processed and can provide an accurate indication of the average temperature within the laser tube.

  15. Process for producing enriched uranium having a {sup 235}U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage

    DOE Patents [OSTI]

    Horton, J.A.; Hayden, H.W. Jr.

    1995-05-30T23:59:59.000Z

    An uranium enrichment process capable of producing an enriched uranium, having a {sup 235}U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower {sup 235}U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF{sub 6} tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a {sup 235} U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % {sup 235} U; fluorinating this enriched metallic uranium isotopic mixture to form UF{sub 6}; processing the resultant isotopic mixture of UF{sub 6} in a gaseous diffusion process to produce a final enriched uranium product having a {sup 235}U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low {sup 235}U content UF{sub 6} having a {sup 235}U content of about 0.71 wt. % of the total uranium content of the low {sup 235}U content UF{sub 6}; and converting this low {sup 235}U content UF{sub 6} to metallic uranium for recycle to the atomic vapor laser isotope separation process. 4 figs.

  16. Process for producing enriched uranium having a .sup.235 U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage

    DOE Patents [OSTI]

    Horton, James A. (Livermore, CA); Hayden, Jr., Howard W. (Oakridge, TN)

    1995-01-01T23:59:59.000Z

    An uranium enrichment process capable of producing an enriched uranium, having a .sup.235 U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower .sup.235 U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF.sub.6 tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a .sup.235 U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % .sup.235 U; fluorinating this enriched metallic uranium isotopic mixture to form UF.sub.6 ; processing the resultant isotopic mixture of UF.sub.6 in a gaseous diffusion process to produce a final enriched uranium product having a .sup.235 U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low .sup.235 U content UF.sub.6 having a .sup.235 U content of about 0.71 wt. % of the total uranium content of the low .sup.235 U content UF.sub.6 ; and converting this low .sup.235 U content UF.sub.6 to metallic uranium for recycle to the atomic vapor laser isotope separation process.

  17. alkali atom vapor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    low power requirements, these "chip-scale" atomic Popovic, Zoya 3 Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas M. V. Romalis Physics...

  18. Precision micro drilling with copper vapor lasers

    SciTech Connect (OSTI)

    Chang, J.J.; Martinez, M.W.; Warner, B.E.; Dragon, E.P.; Huete, G.; Solarski, M.E.

    1994-09-02T23:59:59.000Z

    The authors have developed a copper vapor laser based micro machining system using advanced beam quality control and precision wavefront tilting technologies. Micro drilling has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratio up to 1:40 have been consistently drilled on a variety of metals with good quality. For precision trepanned holes, the hole-to-hole size variation is typically within 1% of its diameter. Hole entrance and exit are both well defined with dimension error less than a few microns. Materialography of sectioned holes shows little (sub-micron scale) recast layer and heat affected zone with surface roughness within 1--2 microns.

  19. Metal vapor laser including hot electrodes and integral wick

    DOE Patents [OSTI]

    Ault, Earl R. (Livermore, CA); Alger, Terry W. (Tracy, CA)

    1995-01-01T23:59:59.000Z

    A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube.

  20. Metal vapor laser including hot electrodes and integral wick

    DOE Patents [OSTI]

    Ault, E.R.; Alger, T.W.

    1995-03-07T23:59:59.000Z

    A metal vapor laser, specifically one utilizing copper vapor, is disclosed herein. This laser utilizes a plasma tube assembly including a thermally insulated plasma tube containing a specific metal, e.g., copper, and a buffer gas therein. The laser also utilizes means including hot electrodes located at opposite ends of the plasma tube for electrically exciting the metal vapor and heating its interior to a sufficiently high temperature to cause the metal contained therein to vaporize and for subjecting the vapor to an electrical discharge excitation in order to lase. The laser also utilizes external wicking arrangements, that is, wicking arrangements located outside the plasma tube. 5 figs.

  1. Injection locked oscillator system for pulsed metal vapor lasers

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Ault, Earl R. (Dublin, CA)

    1988-01-01T23:59:59.000Z

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  2. Laser-induced ionization of Na vapor

    SciTech Connect (OSTI)

    Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

    1982-01-01T23:59:59.000Z

    The production of Na/sub 2//sup +/ ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na/sub 2/ molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na/sub 2/ D/sup 1/PI..mu.. Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na/sub 2//sup +/ ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na/sub 2//sup +/ through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na/sub 2/ molecules.

  3. Magnetic field imaging with atomic Rb vapor

    E-Print Network [OSTI]

    Eugeniy E. Mikhailov; I. Novikova; M. D. Havey; F. A. Narducci

    2009-07-27T23:59:59.000Z

    We demonstrate the possibility of dynamic imaging of magnetic fields using electromagnetically induced transparency in an atomic gas. As an experimental demonstration we employ an atomic Rb gas confined in a glass cell to image the transverse magnetic field created by a long straight wire. In this arrangement, which clearly reveals the essential effect, the field of view is about 2 x 2 mm^2 and the field detection uncertainty is 0.14 mG per 10 um x 10 um image pixel.

  4. An ultra-bright atom laser

    E-Print Network [OSTI]

    V. Bolpasi; N. K. Efremidis; M. J. Morrissey; P. Condylis; D. Sahagun; M. Baker; W. von Klitzing

    2013-11-25T23:59:59.000Z

    We present a novel, ultra-bright atom-laser and ultra-cold thermal atom beam. Using rf-radiation we strongly couple the magnetic hyperfine levels of 87Rb atoms in a magnetically trapped Bose-Einstein condensate. At low rf-frequencies gravity opens a small hole in the trapping potenital and a well collimated, extremely bright atom laser emerges from just below the condensate. As opposed to traditional atom lasers based on weak coupling, this technique allows us to outcouple atoms at an arbitrarily large rate. We demonstrate an increase in flux per atom in the BEC by a factor of sixteen compared to the brightest quasi-continuous atom laser. Furthermore, we produce by two orders of magnitude the coldest thermal atom beam to date (200 nK).

  5. Atomic physics: An almost lightless laser

    E-Print Network [OSTI]

    Vuletic, Vladan

    Lasers are often described in terms of a light field circulating in an optical resonator system. Now a laser has been demonstrated in which the field resides primarily in the atomic medium that is used to generate the light.

  6. atomic recoil laser: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Recoil Laser Quantum Physics (arXiv) Summary: We formulate a wave atom optics theory of the Collective Atomic Recoil Laser, where the atomic center-of-mass motion...

  7. Single Molecule DNA Detection with an Atomic Vapor Notch Filter

    E-Print Network [OSTI]

    Uhland, Denis; Widmann, Matthias; Lee, Sang-Yun; Wrachtrup, Jörg; Gerhardt, Ilja

    2015-01-01T23:59:59.000Z

    The detection of single molecules has facilitated many advances in life- and material-sciences. Commonly, it founds on the fluorescence detection of single molecules, which are for example attached to the structures under study. For fluorescence microscopy and sensing the crucial parameters are the collection and detection efficiency, such that photons can be discriminated with low background from a labeled sample. Here we show a scheme for filtering the excitation light in the optical detection of single stranded labeled DNA molecules. We use the narrow-band filtering properties of a hot atomic vapor to filter the excitation light from the emitted fluorescence of a single emitter. The choice of atomic sodium allows for the use of fluorescent dyes, which are common in life-science. This scheme enables efficient photon detection, and a statistical analysis proves an enhancement of the optical signal of more than 15% in a confocal and in a wide-field configuration.

  8. High average power magnetic modulator for metal vapor lasers

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Cook, Edward G. (Livermore, CA); Miller, John L. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A three-stage magnetic modulator utilizing magnetic pulse compression designed to provide a 60 kV pulse to a copper vapor laser at a 4.5 kHz repetition rate is disclosed. This modulator operates at 34 kW input power. The circuit includes a step up auto transformer and utilizes a rod and plate stack construction technique to achieve a high packing factor.

  9. Channelization architecture for wide-band slow light in atomic vapors

    E-Print Network [OSTI]

    Zachary Dutton; Mark Bashkansky; Michael Steiner; John Reintjes

    2005-10-20T23:59:59.000Z

    We propose a ``channelization'' architecture to achieve wide-band electromagnetically induced transparency (EIT) and ultra-slow light propagation in atomic Rb-87 vapors. EIT and slow light are achieved by shining a strong, resonant ``pump'' laser on the atomic medium, which allows slow and unattenuated propagation of a weaker ``signal'' beam, but only when a two-photon resonance condition is satisfied. Our wideband architecture is accomplished by dispersing a wideband signal spatially, transverse to the propagation direction, prior to entering the atomic cell. When particular Zeeman sub-levels are used in the EIT system, then one can introduce a magnetic field with a linear gradient such that the two-photon resonance condition is satisfied for each individual frequency component. Because slow light is a group velocity effect, utilizing differential phase shifts across the spectrum of a light pulse, one must then introduce a slight mismatch from perfect resonance to induce a delay. We present a model which accounts for diffusion of the atoms in the varying magnetic field as well as interaction with levels outside the ideal three-level system on which EIT is based. We find the maximum delay-bandwidth product decreases with bandwidth, and that delay-bandwidth product ~1 should be achievable with bandwidth ~50 MHz (~5 ns delay). This is a large improvement over the ~1 MHz bandwidths in conventional slow light systems and could be of use in signal processing applications.

  10. Laser trapping of {sup 21}Na atoms

    SciTech Connect (OSTI)

    Lu, Zheng-Tian

    1994-09-01T23:59:59.000Z

    This thesis describes an experiment in which about four thousand radioactive {sup 21}Na (t{sub l/2} = 22 sec) atoms were trapped in a magneto-optical trap with laser beams. Trapped {sup 21}Na atoms can be used as a beta source in a precision measurement of the beta-asymmetry parameter of the decay of {sup 21}Na {yields} {sup 21}Ne + {Beta}{sup +} + v{sub e}, which is a promising way to search for an anomalous right-handed current coupling in charged weak interactions. Although the number o trapped atoms that we have achieved is still about two orders of magnitude lower than what is needed to conduct a measurement of the beta-asymmetry parameter at 1% of precision level, the result of this experiment proved the feasibility of trapping short-lived radioactive atoms. In this experiment, {sup 21}Na atoms were produced by bombarding {sup 24}Mg with protons of 25 MeV at the 88 in. Cyclotron of Lawrence Berkeley Laboratory. A few recently developed techniques of laser manipulation of neutral atoms were applied in this experiment. The {sup 21}Na atoms emerging from a heated oven were first transversely cooled. As a result, the on-axis atomic beam intensity was increased by a factor of 16. The atoms in the beam were then slowed down from thermal speed by applying Zeeman-tuned slowing technique, and subsequently loaded into a magneto-optical trap at the end of the slowing path. The last two chapters of this thesis present two studies on the magneto-optical trap of sodium atoms. In particular, the mechanisms of magneto-optical traps at various laser frequencies and the collisional loss mechanisms of these traps were examined.

  11. Methods for reducing the loss of metal in a metal vapor laser

    DOE Patents [OSTI]

    Duncan, David B. (Auburn, CA); Alger, Terry W. (Tracy, CA)

    1990-01-01T23:59:59.000Z

    Methods are provided for reducing loss of metal from a metal vapor laser by collecting metal present outside the hot zone of the laser and introducing or confining it in the hot zone.

  12. Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

    DOE Patents [OSTI]

    Yeung, E.S.; Chang, Y.C.

    1999-06-29T23:59:59.000Z

    The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent. 8 figs.

  13. Metal film deposition by laser breakdown chemical vapor deposition

    SciTech Connect (OSTI)

    Jervis, T.R.

    1985-01-01T23:59:59.000Z

    Dielectric breakdown of gas mixtures can be used to deposit homogeneous thin films by chemical vapor deposition with appropriate control of flow and pressure conditions to suppress gas phase nucleation and particle formation. Using a pulsed CO/sub 2/ laser operating at 10.6 microns where there is no significant resonant absorption in any of the source gases, we have succeeded in depositing homogeneous films from several gas phase precursors by gas phase laser pyrolysis. Nickel and molybdenum from the respective carbonyls and tungsten from the hexafluoride have been examined to date. In each case the gas precursor is buffered to reduce the partial pressure of the reactants and to induce breakdown. The films are spectrally reflective and uniform over a large area. Films have been characterized by Auger electron spectroscopy, x-ray diffraction, pull tests, and resistivity measurements. The highest quality films have resulted from the nickel depositions. Detailed x-ray diffraction analysis of these films yields a very small domain size (approx. 50 A) consistent with rapid quenching from the gas phase reaction zone. This analysis also shows nickel carbide formation consistent with the temperature of the reaction zone and the Auger electron spectroscopy results which show some carbon and oxygen incorporation (8% and 1% respectively). Gas phase transport and condensation of the molybdenum carbonyl results in substantial carbon and oxygen contamination of the molybdenum films requiring heated substrates, a requirement not consistent with the goals of the program to maximize the quench rate of the deposition. Results from tungsten deposition experiments representing a reduction chemistry instead of the decomposition chemistry involved in the carbonyl experiments are also reported.

  14. Broadband laser cooling of trapped atoms with ultrafast pulses

    E-Print Network [OSTI]

    B. B. Blinov; R. N. Kohn Jr.; M. J. Madsen; P. Maunz; D. L. Moehring; C. Monroe

    2005-07-07T23:59:59.000Z

    We demonstrate broadband laser cooling of atomic ions in an rf trap using ultrafast pulses from a modelocked laser. The temperature of a single ion is measured by observing the size of a time-averaged image of the ion in the known harmonic trap potential. While the lowest observed temperature was only about 1 K, this method efficiently cools very hot atoms and can sufficiently localize trapped atoms to produce near diffraction-limited atomic images.

  15. Metal vapor target for precise studies of ion-atom collisions

    SciTech Connect (OSTI)

    Chen, W., E-mail: w.chen@gsi.de; Vorobyev, G.; Herfurth, F.; Hillenbrand, P.-M.; Spillmann, U. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Guo, D. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000 Gansu (China); Trotsenko, S. [Helmholtz-Institut Jena Fröbelstieg 3, 07743 Jena (Germany); Gumberidze, A. [ExtreMe Matter Institute EMMI and Research Division, GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); FIAS Frankfurt Institute for Advanced Studies, 60438 Frankfurt am Main (Germany); Stöhlker, Th. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Helmholtz-Institut Jena Fröbelstieg 3, 07743 Jena (Germany)

    2014-05-15T23:59:59.000Z

    Although different ion-atom collisions have been studied in various contexts, precise values of cross-sections for many atomic processes were seldom obtained. One of the main uncertainties originates from the value of target densities. In this paper, we describe a unique method to measure a target density precisely with a combination of physical vapor deposition and inductively coupled plasma optical emission spectrometry. This method is preliminarily applied to a charge transfer cross-section measurement in collisions between highly charged ions and magnesium vapor. The final relative uncertainty of the target density is less than 2.5%. This enables the precise studies of atomic processes in ion-atom collisions, even though in the trial test the deduction of precise capture cross-sections was limited by other systematic errors.

  16. Storage and Retrieval of Thermal Light in Warm Atomic Vapor

    E-Print Network [OSTI]

    Young-Wook Cho; Yoon-Ho Kim

    2010-07-12T23:59:59.000Z

    We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically-induced transparency (EIT). We first demonstrate slowed-propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown$-$Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics is preserved during the storage and retrieval process.

  17. Numerical investigation of a transient free jet resembling a laser-produced vapor jet

    E-Print Network [OSTI]

    Budair, Mohammed Omar

    Numerical investigation of a transient free jet resembling a laser-produced vapor jet G.M. Arshed in revised form 29 July 2003 Abstract In the present study, the transiently developing free jet emanating from a laser-impacted surface is considered. The jet velocity profiles are varied with time

  18. Measurement of Water Vapor Concentration using Tunable Diode Laser Absorption Spectroscopy

    E-Print Network [OSTI]

    Barrett, Alexander B.

    2010-07-14T23:59:59.000Z

    Tunable diode laser spectroscopy and the Beer-Lambert relation has been used to measure the absorption of water vapor both in an absorption cell and in a shock tube. The purpose of this thesis is to develop a laser diagnostic capable of determining...

  19. Development of laser excited atomic fluorescence and ionization methods

    SciTech Connect (OSTI)

    Winefordner, J.D.

    1991-01-01T23:59:59.000Z

    Progress report: May 1, 1988 to December 31, 1991. The research supported by DE-FG05-88ER13881 during the past (nearly) 3 years can be divided into the following four categories: (1) theoretical considerations of the ultimate detection powers of laser fluorescence and laser ionization methods; (2) experimental evaluation of laser excited atomic fluorescence; (3) fundamental studies of atomic and molecular parameters in flames and plasmas; (4) other studies.

  20. Broadband laser cooling of trapped atoms with ultrafast pulses

    E-Print Network [OSTI]

    Blinov, Boris

    Broadband laser cooling of trapped atoms with ultrafast pulses B. B. Blinov,* R. N. Kohn, Jr., M. J ions in an rf trap using ultrafast pulses from a mode-locked laser. The temperature of a single ion On the other hand, an ultrafast laser whose pulse is a few picoseconds long will naturally have a bandwidth

  1. Loading atom lasers by collectivity-enhanced optical pumping

    SciTech Connect (OSTI)

    Macovei, Mihai A.; Evers, Joerg [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

    2010-01-15T23:59:59.000Z

    The effect of collectivity on the loading of an atom laser via optical pumping is discussed. In our model, atoms in a beam are laser-excited and subsequently spontaneously decay into a trapping state. We consider the case of sufficiently high particle density in the beam such that the spontaneous emission is modified by the particle interaction. We show that the collective effects lead to a better population of the trapping state over a wide range of system parameters, and that the second-order correlation function of the atoms can be controlled by the applied laser field.

  2. Influence of coherent Raman scattering on coherent population trapping in atomic sodium vapor

    SciTech Connect (OSTI)

    Wong, Vincent; Bennink, Ryan S.; Marino, Alberto M.; Boyd, Robert W.; Stroud, C.R. Jr.; Narducci, F.A. [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); EO Sensors Division, Naval Air Systems Command, Patuxent River, Maryland 20670 (United States)

    2004-11-01T23:59:59.000Z

    We study how coherent Stokes and anti-Stokes Raman scattering influence coherent population trapping. In an experiment using an atomic sodium vapor cell we observe induced transparency, induced absorption, and gain features, all of subnatural linewidth. The electromagnetically induced resonance is a peak or a dip depending on which side of the optical transition the fields are tuned to, and thus whether coherent anti-Stokes Raman scattering or coherent Stokes Raman scattering is the dominant process.

  3. Light storage in a room temperature atomic vapor based on coherent population oscillations

    E-Print Network [OSTI]

    M. -A. Maynard; F. Bretenaker; F. Goldfarb

    2014-10-21T23:59:59.000Z

    We report the experimental observation of Coherent Population Oscillation (CPO) based light storage in an atomic vapor cell at room temperature. Using the ultranarrow CPO between the ground levels of a $\\Lambda$ system selected by polarization in metastable $^4$He, such a light storage is experimentally shown to be phase preserving. As it does not involve any atomic coherences it has the advantage of being robust to dephasing effects such as small magnetic field inhomogeneities. The storage time is limited by the population lifetime of the ground states of the $\\Lambda$ system.

  4. Estimation of temporal separation of slow light pulses in atomic vapors by weak measurement

    E-Print Network [OSTI]

    Pardeep Kumar; Shubhrangshu Dasgupta

    2015-03-16T23:59:59.000Z

    We show how two circular polarization components of a linearly polarized pulse, propagating through a coherently driven dilute atomic vapor, can be well resolved in time domain by weak measurement. Slower group velocity of one of the components due to electromagnetically induced transparency leads to a differential group delay between the two components. For low number density, this delay may not be large enough to temporally resolve the two components. We show how this can be enhanced in terms of mean time of arrival of the output pulse through a post-selected polarizer. We demonstrate the idea with all the analytical and numerical results, with a specific example of alkali atoms.

  5. Laser system for secondary cooling of {sup 87}Sr atoms

    SciTech Connect (OSTI)

    Khabarova, K Yu; Slyusarev, S N; Strelkin, S A; Belotelov, G S; Kostin, A S; Pal'chikov, Vitaly G; Kolachevsky, Nikolai N

    2012-11-30T23:59:59.000Z

    A laser system with a narrow generation line for secondary laser cooling of {sup 87}Sr atoms has been developed and investigated. It is planned to use ultracold {sup 87}Sr atoms loaded in an optical lattice in an optical frequency standard. To this end, a 689-nm semiconductor laser has been stabilised using an external reference ultrastable cavity with vibrational and temperature compensation near the critical point. The lasing spectral width was 80 Hz (averaging time 40 ms), and the frequency drift was at a level of 0.3 Hz s{sup -1}. Comparison of two independent laser systems yielded a minimum Allan deviation: 2 Multiplication-Sign 10{sup -14} for 300-s averaging. It is shown that this system satisfies all requirements necessary for secondary cooling of 87Sr atoms using the spectrally narrow {sup 1}S{sub 0} - {sup 3}P{sub 1} transition ({lambda} = 689 nm). (cooling of atoms)

  6. Ultralow-power local laser control of the dimer density in alkali-metal vapors

    E-Print Network [OSTI]

    Jha, Pankaj K; Yi, Zhenhuan; Yuan, Luqi; Sautenkov, Vladimir A; Rostovtsev, Yuri V; Welch, George R; Zheltikov, Aleksei M; Scully, Marlan O

    2011-01-01T23:59:59.000Z

    Ultralow-power diode-laser radiation is employed to induce photodesorption of cesium from a partially transparent thin-film cesium adsorbate on a solid surface. Using resonant Raman spectroscopy, we demonstrate that this photodesorption process enables an accurate local optical control of the density of dimer molecules in alkali-metal vapors.

  7. An atomic-scale analysis of catalytically-assisted chemical vapor deposition of carbon nanotubes

    E-Print Network [OSTI]

    Grujicic, Mica

    Growth of carbon nanotubes during transition-metal particles catalytically-assisted thermal decomposition of the transition-metal particles and onto the surface of carbon nanotubes, carbon atom attachment to the growing. Carbon nanotubes are generally processed by laser ablation of carbon rods e.g. [7], a direct current arc

  8. Four-level atom interferometer with trichromatic laser fields

    SciTech Connect (OSTI)

    Honda, Kazuhito; Kobayashi, Yoshiyuki; Morinaga, Atsuo [Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510 (Japan)

    2007-02-15T23:59:59.000Z

    A four-level atom interferometer comprised of three excited states and one ground state with trichromatic fields coupled between them is investigated using Zeeman sublevels of {sup 3}P{sub 1} and {sup 1}S{sub 0} states of a calcium atom. A theoretical description of the interaction of four-level atoms with trichromatic laser fields is presented and compared with the experimental results of the interference fringes which are generated by the three excited states.

  9. Ultraslow propagation of matched pulses by four-wave mixing in an atomic vapor

    E-Print Network [OSTI]

    V. Boyer; C. F. McCormick; E. Arimondo; P. D. Lett

    2007-03-19T23:59:59.000Z

    We have observed the ultraslow propagation of matched pulses in nondegenerate four-wave mixing in a hot atomic vapor. Probe pulses as short as 70 ns can be delayed by a tunable time of up to 40 ns with little broadening or distortion. During the propagation, a probe pulse is amplified and generates a conjugate pulse which is faster and separates from the probe pulse before getting locked to it at a fixed delay. The precise timing of this process allows us to determine the key coefficients of the susceptibility tensor. The presence of gain in this system makes this system very interesting in the context of all-optical information processing.

  10. Laser-induced nonresonant nuclear excitation in muonic atoms

    E-Print Network [OSTI]

    A. Shahbaz; C. Müller; T. J. Buervenich; C. H. Keitel

    2008-12-13T23:59:59.000Z

    Coherent nuclear excitation in strongly laser-driven muonic atoms is calculated. The nuclear transition is caused by the time-dependent Coulomb field of the oscillating charge density of the bound muon. A closed-form analytical expression for electric multipole transitions is derived and applied to various isotopes; the excitation probabilities are in general very small. We compare the process with other nuclear excitation mechanisms through coupling with atomic shells and discuss the prospects to observe it in experiment.

  11. Long Range Interactions With Laser Cooled Neutral Atoms

    SciTech Connect (OSTI)

    Gattobigio, Giovanni Luca [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne France (France); Dipartimento di Fisica dell'Universita di Ferrara, 44100 Ferrara (Italy); Michaud, Franck; Labeyrie, Guillaume; Kaiser, Robin [Institut Non Lineaire de Nice, Universite de Nice-Sophia-Antipolis, CNRS UMR 661, 1361, route des Lucioles 06560 Valbonne (France); Loureiro, Jorge; Mendonca, Jose Tito; Tercas, Hugo [Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049-001 Lisboa (Portugal); Pohl, Thomas [ITAMP, 60 Garden Street, Cambridge, MA 02138 (United States)

    2008-09-07T23:59:59.000Z

    Multiple scattering of light in a trap of laser cooled neutral atoms leads to repulsion forces between the atoms. The corresponding interactions have long range behavior in 1/r{sup 2} and are thus similar to Coulomb interaction in an one component confined plasma. Consequences of these interactions will be described in this paper, including the limitation of the spatial density one can obtain in such systems and self-sustained oscillations of the cloud.

  12. Kinetics of laser pulse vaporization of uranium dioxide by mass spectrometry

    SciTech Connect (OSTI)

    Tsai, C.

    1981-11-01T23:59:59.000Z

    Safety analyses of nuclear reactors require knowledge of the evaporation behavior of UO/sub 2/ at temperatures well above the melting point of 3140 K. In this study, rapid transient heating of a small spot on a UO/sub 2/ specimen was accomplished by a laser pulse, which generates a surface temperature excursion. This in turn vaporizes the target surface and the gas expands into vacuum. The surface temperature transient was monitored by a fast-response automatic optical pyrometer. The maximum surface temperatures investigated range from approx. 3700 K to approx. 4300 K. A computer program was developed to simulate the laser heating process and calculate the surface temperature evolution. The effect of the uncertainties of the high temperature material properties on the calculation was included in a sensitivity study for UO/sub 2/ vaporization. The measured surface temperatures were in satisfactory agreements.

  13. Optical emission spectroscopy of metal vapor dominated laser-arc hybrid welding plasma

    SciTech Connect (OSTI)

    Ribic, B.; DebRoy, T. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Burgardt, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2011-04-15T23:59:59.000Z

    During laser-arc hybrid welding, plasma properties affect the welding process and the weld quality. However, hybrid welding plasmas have not been systematically studied. Here we examine electron temperatures, species densities, and electrical conductivity for laser, arc, and laser-arc hybrid welding using optical emission spectroscopy. The effects of arc currents and heat source separation distances were examined because these parameters significantly affect weld quality. Time-average plasma electron temperatures, electron and ion densities, electrical conductivity, and arc stability decrease with increasing heat source separation distance during hybrid welding. Heat source separation distance affects these properties more significantly than the arc current within the range of currents considered. Improved arc stability and higher electrical conductivity of the hybrid welding plasma result from increased heat flux, electron temperatures, electron density, and metal vapor concentrations relative to arc or laser welding.

  14. Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

    E-Print Network [OSTI]

    Toshiyuki Hosoya; Martin Miranda; Ryotaro Inoue; Mikio Kozuma

    2014-12-02T23:59:59.000Z

    We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system, which does not depend on complex nonlinear frequency-doubling, has great importance for implementing transportable optical lattice clocks, and is also useful for investigations on condensed matter physics or quantum information processing using cold atoms.

  15. Intensity-resolved Above Threshold Ionization Yields of Atoms with Ultrashort Laser Pulses

    E-Print Network [OSTI]

    Hart, Nathan Andrew

    2012-10-19T23:59:59.000Z

    The above threshold ionization (ATI) spectra provide a diversity of information about a laser-atom ionization process such as laser intensity, pulse duration, carrier envelope phase, and atomic energy level spacing. However, the spatial distribution...

  16. Rescattering effects in laser-assisted electron-atom bremsstrahlung

    E-Print Network [OSTI]

    Zheltukhin, A N; Frolov, M V; Manakov, N L; Starace, Anthony F

    2015-01-01T23:59:59.000Z

    Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) co...

  17. Rescattering effects in laser-assisted electron-atom bremsstrahlung

    E-Print Network [OSTI]

    A. N. Zheltukhin; A. V. Flegel; M. V. Frolov; N. L. Manakov; Anthony F. Starace

    2015-02-01T23:59:59.000Z

    Rescattering effects in nonresonant spontaneous laser-assisted electron-atom bremsstrahlung (LABrS) are analyzed within the framework of time-dependent effective-range (TDER) theory. It is shown that high energy LABrS spectra exhibit rescattering plateau structures that are similar to those that are well-known in strong field laser-induced processes as well as those that have been predicted theoretically in laser-assisted collision processes. In the limit of a low-frequency laser field, an analytic description of LABrS is obtained from a rigorous quantum analysis of the exact TDER results for the LABrS amplitude. This amplitude is represented as a sum of factorized terms involving three factors, each having a clear physical meaning. The first two factors are the exact field-free amplitudes for electron-atom bremsstrahlung and for electron-atom scattering, and the third factor describes free electron motion in the laser field along a closed trajectory between the first (scattering) and second (rescattering) collision events. Finally, a generalization of these TDER results to the case of LABrS in a Coulomb field is discussed.

  18. Pore evolution during high pressure atomic vapor deposition D. D. Hass Y. Y. Yang H. N. G. Wadley

    E-Print Network [OSTI]

    Wadley, Haydn

    The development of physical vapor deposition systems that employ inert gas jets to entrain and deposit atomic conditions can contain a higher volume fraction of porosity and a different pore morphology to coatings created by conventional, low pressure (\\10-4 Pa) deposition processes. A recent direct simulation Monte

  19. Synthesis of multiferroic Er-Fe-O thin films by atomic layer and chemical vapor deposition

    SciTech Connect (OSTI)

    Mantovan, R., E-mail: roberto.mantovan@mdm.imm.cnr.it; Vangelista, S.; Wiemer, C.; Lamperti, A.; Tallarida, G. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Chikoidze, E.; Dumont, Y. [GEMaC, Université de Versailles St. Quentin en Yvelines-CNRS, Versailles (France); Fanciulli, M. [Laboratorio MDM IMM-CNR, I-20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, Milano (Italy)

    2014-05-07T23:59:59.000Z

    R-Fe-O (R?=?rare earth) compounds have recently attracted high interest as potential new multiferroic materials. Here, we report a method based on the solid-state reaction between Er{sub 2}O{sub 3} and Fe layers, respectively grown by atomic layer deposition and chemical vapor deposition, to synthesize Er-Fe-O thin films. The reaction is induced by thermal annealing and evolution of the formed phases is followed by in situ grazing incidence X-ray diffraction. Dominant ErFeO{sub 3} and ErFe{sub 2}O{sub 4} phases develop following subsequent thermal annealing processes at 850?°C in air and N{sub 2}. Structural, chemical, and morphological characterization of the layers are conducted through X-ray diffraction and reflectivity, time-of-flight secondary ion-mass spectrometry, and atomic force microscopy. Magnetic properties are evaluated by magnetic force microscopy, conversion electron Mössbauer spectroscopy, and vibrating sample magnetometer, being consistent with the presence of the phases identified by X-ray diffraction. Our results constitute a first step toward the use of cost-effective chemical methods for the synthesis of this class of multiferroic thin films.

  20. Photoresponse properties of large-area MoS{sub 2} atomic layer synthesized by vapor phase deposition

    SciTech Connect (OSTI)

    Luo, Siwei; Qi, Xiang, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn; Ren, Long; Hao, Guolin; Fan, Yinping; Liu, Yundan; Han, Weijia; Zang, Chen; Li, Jun; Zhong, Jianxin, E-mail: xqi@xtu.edu.cn, E-mail: jxzhong@xtu.edu.cn [Hunan Key Laboratory for Micro-Nano Energy Materials and Devices, People's Republic of China Laboratory for Quantum Engineering and Micro-Nano Energy Technology, and Faculty of Materials and Optoelectronic Physics, Xiangtan University, Hunan 411105 (China)

    2014-10-28T23:59:59.000Z

    Photoresponse properties of a large area MoS{sub 2} atomic layer synthesized by vapor phase deposition method without any catalyst are studied. Scanning electron microscopy, atomic force microscopy, Raman spectrum, and photoluminescence spectrum characterizations confirm that the two-dimensional microstructures of MoS{sub 2} atomic layer are of high quality. Photoelectrical results indicate that the as-prepared MoS{sub 2} devices have an excellent sensitivity and a good reproducibility as a photodetector, which is proposed to be ascribed to the potential-assisted charge separation mechanism.

  1. Very-high-order harmonic generation from Ar atoms and Ar+ ions in superintense pulsed laser

    E-Print Network [OSTI]

    Chu, Shih-I

    Very-high-order harmonic generation from Ar atoms and Ar+ ions in superintense pulsed laser fields-high-order harmonic generation HHG from Ar atoms and Ar+ ions by means of the self-interaction-free time-order harmonic generation HHG is one of the most rapidly developing topics in the field of laser-atom molecule

  2. Alkali vapor pressure modulation on the 100 ms scale in a single-cell vacuum system for cold atom experiments

    SciTech Connect (OSTI)

    Dugrain, Vincent; Reichel, Jakob [Laboratoire Kastler Brossel, ENS, UPMC, CNRS, 24 rue Lhomond, 75005 Paris (France); Rosenbusch, Peter [LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 av de l’Observatoire, 75014 Paris (France)

    2014-08-15T23:59:59.000Z

    We describe and characterize a device for alkali vapor pressure modulation on the 100 ms timescale in a single-cell cold atom experiment. Its mechanism is based on optimized heat conduction between a current-modulated alkali dispenser and a heat sink at room temperature. We have studied both the short-term behavior during individual pulses and the long-term pressure evolution in the cell. The device combines fast trap loading and relatively long trap lifetime, enabling high repetition rates in a very simple setup. These features make it particularly suitable for portable atomic sensors.

  3. E-Print Network 3.0 - atom-photon pair laser Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    quantum communication and a first... pairs of counterpropagating laser beams for optical cooling. Fluorescence light is collected... photon 5 . This kind of atom-photon...

  4. Ultralow-power local laser control of the dimer density in alkali-metal vapors through photodesorption

    E-Print Network [OSTI]

    Pankaj K. Jha; Konstantin E. Dorfman; Zhenhuan Yi; Luqi Yuan; Vladimir A. Sautenkov; Yuri V. Rostovtsev; George R. Welch; Aleksei M. Zheltikov; Marlan O. Scully

    2012-10-08T23:59:59.000Z

    Ultralow-power diode-laser radiation is employed to induce photodesorption of cesium from a partially transparent thin-film cesium adsorbate on a solid surface. Using resonant Raman spectroscopy, we demonstrate that this photodesorption process enables an accurate local optical control of the density of dimer molecules in alkali-metal vapors.

  5. Laser action in para-quaterphenyl vapor pumped by XeCl* laser radiation

    SciTech Connect (OSTI)

    Danilova, V.I.; Degtyarenko, K.M.; Gruzinskii, V.V.; Kopylova, T.N.; Maier, G.V.; Tarasenko, V.F.

    1980-05-01T23:59:59.000Z

    A new approach is proposed to the search for active media involving a theoretical study of the spectral, luminescence, and lasing properties of organic molecules. Laser action was obtained in gas-phase para-quaterphenyl (lambda/sub l/=361.5 nm) with a low threshold pumping level (1.1 MW/cm/sup 2/). The lasing capacity of some substituted forms of para-quaterphenyl is predicted.

  6. Request for Support for the Conference on Super Intense Laser Atom Physics

    SciTech Connect (OSTI)

    Todd Ditmire

    2004-10-21T23:59:59.000Z

    The Conference on Super Intense Laser Atom Physics (SILAP) was held in November 2003 in Dallas, Texas. The venue for the meeting was South Fork Ranch in the outskirts of Dallas. The topics of the meeting included high harmonic generation and attosecond pulse generation, strong field interactions with molecules and clusters, particle acceleration, and relativistic laser atom interactions.

  7. Improvement by laser quenching of an "atom diode": a one-way barrier for ultra-cold atoms

    E-Print Network [OSTI]

    A Ruschhaupt; J G Muga; M G Raizen

    2006-01-31T23:59:59.000Z

    Different laser devices working as ``atom diodes'' or ``one-way barriers'' for ultra-cold atoms have been proposed recently. They transmit ground state level atoms coming from one side, say from the left, but reflect them when they come from the other side. We combine a previous model, consisting of the stimulated Raman adiabatic passage (STIRAP) from the ground to an excited state and a state-selective mirror potential, with a localized quenching laser which produces spontaneous decay back to the ground state. This avoids backwards motion, provides more control of the decay process and therefore a more compact and useful device.

  8. Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids

    E-Print Network [OSTI]

    Peinke, Joachim

    Control of ultrafast electron dynamics with shaped femtosecond laser pulses: from atoms to solids;1. Introduction In coherent control shaped femtosecond laser pulses are used as a tool to steer the ultrafast focus on advanced control of ultrafast electron dynamics with shaped femtosecond laser pulses

  9. Laser spectroscopic studies of state-dependent collisional quenching of the lifetimes of metastable antiprotonic helium atoms

    E-Print Network [OSTI]

    Hori, M; Torii, H A; Ishikawa, T; Maas, F E; Yamazaki, T; Eades, John; Widmann, E; Kumakara, M; Morita, N; Sugai, I; Horváth, D; Ketzer, B; Hartmann, F J; Maierl, C; Hasinoff, M D; Von Egidy, T; Tamura, H

    1998-01-01T23:59:59.000Z

    Laser spectroscopic studies of state-dependent collisional quenching of the lifetimes of metastable antiprotonic helium atoms

  10. Laser-excited atomic fluorescence spectrometry in a graphite furnace with an

    E-Print Network [OSTI]

    Michel, Robert G.

    must provide high peak energy above sequentially with the analysis time determined primarilyLaser-excited atomic fluorescence spectrometry in a graphite furnace with an optical parametric for electrothermal atomic excited atomic ¯ uorescence spectrometry (LEAFS ) in a absorption spectrometry (ETAAS

  11. Dimensional scaling treatment of stability of atomic anions induced by superintense, high-frequency laser fields

    E-Print Network [OSTI]

    Kais, Sabre

    and often paradoxical electronic properties of atoms induced by high-frequency superintense radiation fields- lization of multiply charged anions of hydrogen10 and doubly charged anions of helium and lithium atoms.11 of molecular anions. II. LASER ATOM INTERACTION We consider a high-frequency monochromatic electric field

  12. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, R.; Loomis, G.E.; Thomas, I.M.

    1999-03-16T23:59:59.000Z

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (ca. 1.10--1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm. 2 figs.

  13. Optical coatings of variable refractive index and high laser-resistance from physical-vapor-deposited perfluorinated amorphous polymer

    DOE Patents [OSTI]

    Chow, Robert (Livermore, CA); Loomis, Gary E. (Livermore, CA); Thomas, Ian M. (Livermore, CA)

    1999-01-01T23:59:59.000Z

    Variable index optical single-layers, optical multilayer, and laser-resistant coatings were made from a perfluorinated amorphous polymer material by physical vapor deposition. This was accomplished by physically vapor depositing a polymer material, such as bulk Teflon AF2400, for example, to form thin layers that have a very low refractive index (.about.1.10-1.31) and are highly transparent from the ultra-violet through the near infrared regime, and maintain the low refractive index of the bulk material. The refractive index can be varied by simply varying one process parameter, either the deposition rate or the substrate temperature. The thus forming coatings may be utilized in anti-reflectors and graded anti-reflection coatings, as well as in optical layers for laser-resistant coatings at optical wavelengths of less than about 2000 nm.

  14. Laser Programs Highlight 1995

    SciTech Connect (OSTI)

    Jacobs, R.R.

    1997-01-31T23:59:59.000Z

    Our contributions to laser science and technology and corresponding applications range from concept to design of the National Ignition Facility, transfer of Atomic Vapor Laser Isotope Separation technology to the private sector, and from new initiatives in industry and defense to micro-optics for improving human vision.

  15. Numerical simulation of transient, incongruent vaporization induced by high power laser

    SciTech Connect (OSTI)

    Tsai, C.H.

    1981-01-01T23:59:59.000Z

    A mathematical model and numerical calculations were developed to solve the heat and mass transfer problems specifically for uranum oxide subject to laser irradiation. It can easily be modified for other heat sources or/and other materials. In the uranium-oxygen system, oxygen is the preferentially vaporizing component, and as a result of the finite mobility of oxygen in the solid, an oxygen deficiency is set up near the surface. Because of the bivariant behavior of uranium oxide, the heat transfer problem and the oxygen diffusion problem are coupled and a numerical method of simultaneously solving the two boundary value problems is studied. The temperature dependence of the thermal properties and oxygen diffusivity, as well as the highly ablative effect on the surface, leads to considerable non-linearities in both the governing differential equations and the boundary conditions. Based on the earlier work done in this laboratory by Olstad and Olander on Iron and on Zirconium hydride, the generality of the problem is expanded and the efficiency of the numerical scheme is improved. The finite difference method, along with some advanced numerical techniques, is found to be an efficient way to solve this problem.

  16. Laser-excited atomic fluorescence of atoms produced in a graphite furnace

    SciTech Connect (OSTI)

    Goforth, D.; Winefordner, J.D.

    1986-11-01T23:59:59.000Z

    Laser-excited atomic fluorescence in a graphite furnace gives detection limits for Pb, Cu, Mn, Sn, Al, In, Li, and Pt, in the picogram to sub-picogram range. The linear dynamic range for these elements varies from 3 to 7 orders of magnitude. A graphite rod, a plain graphite cup, and a slotted graphite cup are compared as the cuvette in the fluorescence system. Detection limits for a pyrolytic coating, a tantalum foil liner, and a tantalum carbide coating of the graphite cuvette are compared. A hydrogen-argon atmosphere, a low-pressure atmosphere, and an argon atmosphere are compared as the atmosphere surrounding the graphite cuvette. Lastly, Cu and Mn are determined in several standard reference materials.

  17. A self-injected, diode-pumped, solid-state ring laser for laser cooling of Li atoms

    E-Print Network [OSTI]

    Miake, Yudai; O'Hara, Kenneth M; Gensemer, Stephen

    2015-01-01T23:59:59.000Z

    We have constructed a solid-state light source for experiments with laser cooled lithium atoms based on a Nd:YVO$_4$ ring laser with second-harmonic generation. Unidirectional lasing, an improved mode selection, and a high output power of the ring laser was achieved by weak coupling to an external cavity which contained the lossy elements required for single frequency operation. Continuous frequency tuning is accomplished by controlling two PZTs in the internal and the external cavities simultaneously. The light source has been utilized to trap and cool fermionic lithium atoms into the quantum degenerate regime.

  18. Inversion symmetry breaking of atomic bound states in strong and short laser fields

    E-Print Network [OSTI]

    Stooß, Veit; Ott, Christian; Blättermann, Alexander; Ding, Thomas; Pfeifer, Thomas

    2015-01-01T23:59:59.000Z

    In any atomic species, the spherically symmetric potential originating from the charged nucleus results in fundamental symmetry properties governing the structure of atomic states and transition rules between them. If atoms are exposed to external electric fields, these properties are modified giving rise to energy shifts such as the AC Stark-effect in varying fields and, contrary to this in a constant (DC) electric field for high enough field strengths, the breaking of the atomic symmetry which causes fundamental changes in the atom's properties. This has already been observed for atomic Rydberg states with high principal quantum numbers. Here, we report on the observation of symmetry breaking effects in Helium atoms for states with principal quantum number n=2 utilizing strong visible laser fields. These findings were enabled by temporally resolving the dynamics better than the sub-optical cycle of the applied laser field, utilizing the method of attosecond transient absorption spectroscopy (ATAS). We ident...

  19. A low phase noise microwave frequency synthesis for a high-performance cesium vapor cell atomic clock

    SciTech Connect (OSTI)

    François, B.; Boudot, R. [FEMTO-ST, CNRS, Université de Franche-Comté, 26 chemin de l'Epitaphe, 25030 Besançon (France); Calosso, C. E. [INRIM, Strada delle Cacce 91, 10135 Torino (Italy); Danet, J. M. [LNE-SYRTE, Observatoire de Paris, CNRS-UPMC, 61 avenue de l'Observatoire, 75014 Paris (France)

    2014-09-15T23:59:59.000Z

    We report the development, absolute phase noise, and residual phase noise characterization of a 9.192?GHz microwave frequency synthesis chain devoted to be used as a local oscillator in a high-performance cesium vapor cell atomic clock based on coherent population trapping (CPT). It is based on frequency multiplication of an ultra-low phase noise 100 MHz oven-controlled quartz crystal oscillator using a nonlinear transmission line-based chain. Absolute phase noise performances of the 9.192?GHz output signal are measured to be ?42, ?100, ?117 dB?rad{sup 2}/Hz and ?129 dB?rad{sup 2}/Hz at 1 Hz, 100 Hz, 1 kHz, and 10 kHz offset frequencies, respectively. Compared to current results obtained in a state-of-the-art CPT-based frequency standard developed at LNE-SYRTE, this represents an improvement of 8 dB and 10 dB at f = 166 Hz and f = 10 kHz, respectively. With such performances, the expected Dick effect contribution to the atomic clock short term frequency stability is reported at a level of 6.2 × 10{sup ?14} at 1 s integration time, that is a factor 3 higher than the atomic clock shot noise limit. Main limitations are pointed out.

  20. Quantum Control of Qubits and Atomic Motion Using Ultrafast Laser Pulses

    E-Print Network [OSTI]

    J. Mizrahi; B. Neyenhuis; K. Johnson; W. C. Campbell; C. Senko; D. Hayes; C. Monroe

    2013-07-01T23:59:59.000Z

    Pulsed lasers offer significant advantages over CW lasers in the coherent control of qubits. Here we review the theoretical and experimental aspects of controlling the internal and external states of individual trapped atoms with pulse trains. Two distinct regimes of laser intensity are identified. When the pulses are sufficiently weak that the Rabi frequency $\\Omega$ is much smaller than the trap frequency $\\otrap$, sideband transitions can be addressed and atom-atom entanglement can be accomplished in much the same way as with CW lasers. By contrast, if the pulses are very strong ($\\Omega \\gg \\otrap$), impulsive spin-dependent kicks can be combined to create entangling gates which are much faster than a trap period. These fast entangling gates should work outside of the Lamb-Dicke regime and be insensitive to thermal atomic motion.

  1. Laser wavelength effects on ionic and atomic emission from tin plasmas D. Campos,a

    E-Print Network [OSTI]

    Harilal, S. S.

    Laser wavelength effects on ionic and atomic emission from tin plasmas D. Campos,a S. S. Harilal centered at 13.5 nm. Spitzer et al.1 reported that tin targets irradiated by a neodymium-doped yttrium alu

  2. Determination of the concentrations of magnesium and aluminum in alloys by laser produced atomic emission spectroscopy 

    E-Print Network [OSTI]

    Ashe, William Monroe

    1997-01-01T23:59:59.000Z

    DETERMINATION OF THE CONCENTRATIONS OF MAGNESIUM AND ALUiiINUM IN ALLOYS BY LASER PRODUCED ATOMIC EMISSION SPECTROSCOPY A Thesis by WILLIAM MONROE ASHE Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the reqmrements for the degree of MASTER OF SCIENCE December 1997 Major Subject: Physics DETERMINATION OF THE CONCENTRATIONS OF MAGNESIUM AND ALUMINUM ALLOYS BY LASER PRODUCED ATOMIC EMISSION SPECTROSCOPY A Thesis by WILLIAM MONROE ASHE...

  3. Slow light propagation and amplification via electromagnetically induced transparency and four-wave mixing in an optically dense atomic vapor

    E-Print Network [OSTI]

    N. B. Phillips; A. V. Gorshkov; I. Novikova

    2009-03-24T23:59:59.000Z

    We experimentally and theoretically analyze the propagation of weak signal field pulses under the conditions of electromagnetically induced transparency (EIT) in hot Rb vapor, and study the effects of resonant four-wave mixing (FWM). In particular, we demonstrate that in a double-$\\Lambda$ system, formed by the strong control field with the weak resonant signal and a far-detuned Stokes field, both continuous-wave spectra and pulse propagation dynamics for the signal field depend strongly on the amplitude of the seeded Stokes field, and the effect is enhanced in optically dense atomic medium. We also show that the theory describing the coupled propagation of the signal and Stokes fields is in good agreement with the experimental observations.

  4. COMBUSTION DRIVEN ATOMIC FLUORINE GENERATORS FOR DF CHEMICAL LASERS Abstract -Conventional high pressure corabustors delivering atomic fluorine for DF chemical

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    compositions assuming frozen isentropic expansion and with or without heat losses in the combustor. The values production at good overall laser power. 1. INTRODUCTION Available references describing combustors for also reactants. Solid propellant com- high production of F atom by thermal equilibrium positions such as NF

  5. Microstructural Evolution During Laser Resolidification of Fe-25 Atom Percent Ge Alloy

    E-Print Network [OSTI]

    Srivastava, Kumar Vaibhav

    selection is discussed using competitive growth kinetics. I. INTRODUCTION TECHNIQUES of rapidly melting the process of laser resolidification. Third, the inti- mate contact of the surface-melted layerMicrostructural Evolution During Laser Resolidification of Fe-25 Atom Percent Ge Alloy KRISHANU

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

    E-Print Network [OSTI]

    Carroll, David L.

    state I. Conventionally, a two-phase (gas-liquid) chemistry singlet oxygen generator (SOG) producesExperimental Effects of Atomic Oxygen on the Development of an Electric Discharge Oxygen Iodine of the electric discharge iodine laser continues, the role of oxygen atoms downstream of the discharge region

  7. Fluctuation properties of laser light after interaction with an atomic system: comparison between two-level and multilevel atomic transitions

    E-Print Network [OSTI]

    Lezama, A; Kastberg, A; Tanzilli, S; Kaiser, R

    2015-01-01T23:59:59.000Z

    The complex internal atomic structure involved in radiative transitions has an effect on the spectrum of fluctuations (noise) of the transmitted light. A degenerate transition has different properties in this respect than a pure two-level transition. We investigate these variations by studying a certain transition between two degenerate atomic levels for different choices of the polarization state of the driving laser. For circular polarization, corresponding to the textbook two-level atom case, the optical spectrum shows the characteristic Mollow triplet for strong laser drive, while the corresponding noise spectrum exhibits squeezing in some frequency ranges. For a linearly polarized drive, corresponding to the case of a multilevel system, additional features appear in both optical and noise spectra. These differences are more pronounced in the regime of a weakly driven transition: whereas the two-level case essentially exhibits elastic scattering, the multilevel case has extra noise terms related to sponta...

  8. RESONANT MULTIPHOTON IONIZATION OF CAESIUM ATOMS BY ULTRA-SHORT LASER PULSES AT 1.06 03BCm

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    610 RESONANT MULTIPHOTON IONIZATION OF CAESIUM ATOMS BY ULTRA-SHORT LASER PULSES AT 1.06 03BCm L. A'atomes de césium, en accordant la fréquence du laser pour qu'il se produise une excitation résonnante à trois photons du niveau 6F. L'expérience a été effectuée en utilisant une impulsion laser de durée 1

  9. Velocity distribution measurements in atomic beams generated using laser induced back-ablation

    E-Print Network [OSTI]

    Denning, A; Lee, S; Ammonson, M; Bergeson, S D

    2008-01-01T23:59:59.000Z

    We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a sub-thermal atomic beam.

  10. Velocity selection of ultra-cold atoms with Fabry-Perot laser devices: improvements and limits

    E-Print Network [OSTI]

    A. Ruschhaupt; F. Delgado; J. G. Muga

    2005-02-28T23:59:59.000Z

    We discuss a method to select the velocities of ultra-cold atoms with a modified Fabry-Perot type of device made of two effective barriers and a well created, respectively, by blue and red detuned lasers. The laser parameters may be used to select the peak and width of the transmitted velocity window. In particular, lowering the central well provides a peak arbitrarily close to zero velocity having a minimum but finite width. The low-energy atomic scattering off this laser device is parameterized and approximate formulae are found to describe and explain its behaviour.

  11. Enhanced reflection via phase compensation from anomalous dispersion in atomic vapor

    SciTech Connect (OSTI)

    Zhang Junxiang; Zhou Haitao [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China); Wang Dawei [Beijing Computational Science Research Center, Beijing 100084 (China); Zhu Shiyao [State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006 (China); Beijing Computational Science Research Center, Beijing 100084 (China); Department of Physics, Hong Kong Baptist University (Hong Kong)

    2011-05-15T23:59:59.000Z

    The phase compensation mechanism induced by anomalous dispersion in the reflection process of four-wave mixing (or reflection from a grating) in a three-level system is investigated, where the four wave vectors do not match in vacuum. An efficiency of the reflected signal of as high as 43% from a hot atomic cell of Cs is observed. The maximum reflection occurs when the frequency of the probe beam (and consequently the frequency of the reflected signal) is slightly red detuned from the transition frequency, which is attributed to the phase compensation from the steep anomalous dispersion accompanied with a strong probe absorption. The dependences of the efficiency on the angle between the coupling and probe lights, on the intensity of the coupling, field and on atomic density are studied. A theoretical model is presented and it is in good agreement with the experimental results.

  12. Helium in chirped laser fields as a time-asymmetric atomic switch

    SciTech Connect (OSTI)

    Kaprálová-Ž?ánská, Petra Ruth, E-mail: kapralova@jh-inst.cas.cz [Department of Radiation and Chemical Physics, Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic); J. Heyrovsky Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague 8 (Czech Republic); Moiseyev, Nimrod, E-mail: nimrod@tx.technion.ac.il [Schulich Faculty of Chemistry and Faculty of Physics, Technion – Israel Institute of Technology, Haifa 32000 (Israel)

    2014-07-07T23:59:59.000Z

    Tuning the laser parameters exceptional points in the spectrum of the dressed laser helium atom are obtained. The weak linearly polarized laser couples the ground state and the doubly excited P-states of helium. We show here that for specific chirped laser pulses that encircle an exceptional point one can get the time-asymmetric phenomenon, where for a negative chirped laser pulse the ground state is transformed into the doubly excited auto-ionization state, while for a positive chirped laser pulse the resonance state is not populated and the neutral helium atoms remains in the ground state as the laser pulse is turned off. Moreover, we show that the results are very sensitive to the closed contour we choose. This time-asymmetric state exchange phenomenon can be considered as a time-asymmetric atomic switch. The optimal time-asymmetric switch is obtained when the closed loop that encircles the exceptional point is large, while for the smallest loops, the time-asymmetric phenomenon does not take place. A systematic way for studying the effect of the chosen closed contour that encircles the exceptional point on the time-asymmetric phenomenon is proposed.

  13. Combined quantum-state preparation and laser cooling of a continuous beam of cold atoms

    SciTech Connect (OSTI)

    Di Domenico, Gianni; Devenoges, Laurent; Dumas, Claire; Thomann, Pierre [Laboratoire Temps-Frequence, Universite de Neuchatel, Avenue de Bellevaux 51, CH-2009 Neuchatel (Switzerland)

    2010-11-15T23:59:59.000Z

    We use two-laser optical pumping on a continuous atomic fountain in order to prepare cold cesium atoms in the same quantum ground state. A first laser excites the F=4 ground state to pump the atoms toward F=3 while a second {pi}-polarized laser excites the F=3{yields}F{sup '}=3 transition of the D{sub 2} line to produce Zeeman pumping toward m=0. To avoid trap states, we implement the first laser in a two-dimensional optical lattice geometry, thereby creating polarization gradients. This configuration has the advantage of simultaneously producing Sisyphus cooling when the optical lattice laser is tuned between the F=4{yields}F{sup '}=4 and F=4{yields}F{sup '}=5 transitions of the D{sub 2} line, which is important to remove the heat produced by optical pumping. Detuning the frequency of the second {pi}-polarized laser reveals the action of a mechanism improving both laser cooling and state-preparation efficiency. A physical interpretation of this mechanism is discussed.

  14. Effects of laser energy and wavelength on the analysis of LiFePO? using laser assisted atom probe tomography

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Santhanagopalan, Dhamodaran [Univ. of California, San Diego, CA (United States); Khalifah, Peter [Stony Brook Univ., NY (United States); Brookhaven National Lab., Upton, NY (United States); Schreiber, Daniel K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Perea, Daniel E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Martens, Richard L. [Univ. of Alabama, Tuscaloosa, AL (United States); Janssen, Yuri [Stony Brook Univ., NY (United States); Meng, Ying Shirley [Univ. of California, San Diego, CA (United States)

    2015-01-01T23:59:59.000Z

    The effects of laser wavelength (355 nm and 532 nm) and laser pulse energy on the quantitative analysis of LiFePO? by atom probe tomography are considered. A systematic investigation of ultraviolet (UV, 355 nm) and green (532 nm) laser assisted field evaporation has revealed distinctly different behaviors. With the use of a UV laser, the major issue was identified as the preferential loss of oxygen (up to 10 at%) while other elements (Li, Fe and P) were observed to be close to nominal ratios. Lowering the laser energy per pulse to 1 pJ/pulse from 50 pJ/pulse increased the observed oxygen concentration to nearer its correct stoichiometry, which was also well correlated with systematically higher concentrations of ¹?O?? ions. Green laser assisted field evaporation led to the selective loss of Li (33% deficiency) and a relatively minor O deficiency. The loss of Li is likely a result of selective dc evaporation of Li between or after laser pulses. Comparison of the UV and green laser data suggests that the green wavelength energy was absorbed less efficiently than the UV wavelength because of differences in absorption at 355 and 532 nm for LiFePO?. Plotting of multihit events on Saxey plots also revealed a strong neutral O? loss from molecular dissociation, but quantification of this loss was insufficient to account for the observed oxygen deficiency.

  15. Effects of laser energy and wavelength on the analysis of LiFePO? using laser assisted atom probe tomography

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Santhanagopalan, Dhamodaran; Khalifah, Peter; Schreiber, Daniel K.; Perea, Daniel E.; Martens, Richard L.; Janssen, Yuri; Meng, Ying Shirley

    2015-01-01T23:59:59.000Z

    The effects of laser wavelength (355 nm and 532 nm) and laser pulse energy on the quantitative analysis of LiFePO? by atom probe tomography are considered. A systematic investigation of ultraviolet (UV, 355 nm) and green (532 nm) laser assisted field evaporation has revealed distinctly different behaviors. With the use of a UV laser, the major issue was identified as the preferential loss of oxygen (up to 10 at%) while other elements (Li, Fe and P) were observed to be close to nominal ratios. Lowering the laser energy per pulse to 1 pJ/pulse from 50 pJ/pulse increased the observed oxygenmore »concentration to nearer its correct stoichiometry, which was also well correlated with systematically higher concentrations of ¹?O?? ions. Green laser assisted field evaporation led to the selective loss of Li (33% deficiency) and a relatively minor O deficiency. The loss of Li is likely a result of selective dc evaporation of Li between or after laser pulses. Comparison of the UV and green laser data suggests that the green wavelength energy was absorbed less efficiently than the UV wavelength because of differences in absorption at 355 and 532 nm for LiFePO?. Plotting of multihit events on Saxey plots also revealed a strong neutral O? loss from molecular dissociation, but quantification of this loss was insufficient to account for the observed oxygen deficiency.« less

  16. Fluctuation properties of laser light after interaction with an atomic system: comparison between two-level and multilevel atomic transitions

    E-Print Network [OSTI]

    A. Lezama; R. Rebhi; A. Kastberg; S. Tanzilli; R. Kaiser

    2015-03-09T23:59:59.000Z

    The complex internal atomic structure involved in radiative transitions has an effect on the spectrum of fluctuations (noise) of the transmitted light. A degenerate transition has different properties in this respect than a pure two-level transition. We investigate these variations by studying a certain transition between two degenerate atomic levels for different choices of the polarization state of the driving laser. For circular polarization, corresponding to the textbook two-level atom case, the optical spectrum shows the characteristic Mollow triplet for strong laser drive, while the corresponding noise spectrum exhibits squeezing in some frequency ranges. For a linearly polarized drive, corresponding to the case of a multilevel system, additional features appear in both optical and noise spectra. These differences are more pronounced in the regime of a weakly driven transition: whereas the two-level case essentially exhibits elastic scattering, the multilevel case has extra noise terms related to spontaneous Raman transitions. We also discuss the possibility to experimentally observe these predicted differences for the commonly encountered case where the laser drive has excess noise in its phase quadrature.

  17. Nonlinear dynamics of ionization stabilization of atoms in intense laser fields

    E-Print Network [OSTI]

    Michael Norman; C. Chandre; T. Uzer; Peijie Wang

    2014-12-06T23:59:59.000Z

    We revisit the stabilization of ionization of atoms subjected to a superintense laser pulse using nonlinear dynamics. We provide an explanation for the lack of complete ionization at high intensity and for the decrease of the ionization probability as intensity is increased. We investigate the role of each part of the laser pulse (ramp-up, plateau, ramp-down) in this process. We emphasize the role of the choice for the ionization criterion, energy versus distance criterion.

  18. Laser scattering by density fluctuations of ultra-cold atoms in a magneto-optical trap

    E-Print Network [OSTI]

    J. T. Mendonça; H. Terças

    2011-04-06T23:59:59.000Z

    We study the spectrum of density fluctuations in the ultra-cold gas of neutral atoms, confined in a magneto-optical trap. We determine the corresponding amplitude and spectra of laser light scattered by this medium. We derive an expression for the dynamical structure function, by using a test particle method. We propose to use the collective laser scattering as a diagnostic method for the microscopic properties of the ultra-cold matter. This will also allow us to check on the atomic correlations which are mediated by the collective mean field inside the gas.

  19. Comparison of precursor infiltration into polymer thin films via atomic layer deposition and sequential vapor infiltration using in-situ quartz crystal microgravimetry

    SciTech Connect (OSTI)

    Padbury, Richard P.; Jur, Jesse S., E-mail: jsjur@ncsu.edu [Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-07-01T23:59:59.000Z

    Previous research exploring inorganic materials nucleation behavior on polymers via atomic layer deposition indicates the formation of hybrid organic–inorganic materials that form within the subsurface of the polymer. This has inspired adaptations to the process, such as sequential vapor infiltration, which enhances the diffusion of organometallic precursors into the subsurface of the polymer to promote the formation of a hybrid organic–inorganic coating. This work highlights the fundamental difference in mass uptake behavior between atomic layer deposition and sequential vapor infiltration using in-situ methods. In particular, in-situ quartz crystal microgravimetry is used to compare the mass uptake behavior of trimethyl aluminum in poly(butylene terephthalate) and polyamide-6 polymer thin films. The importance of trimethyl aluminum diffusion into the polymer subsurface and the subsequent chemical reactions with polymer functional groups are discussed.

  20. Laser safety information for the Atomic, Molecular and Optical (AMO) Physics Labs at Lehigh University modified from the laser safety program developed by the office of Environmental

    E-Print Network [OSTI]

    Huennekens, John

    1 Laser safety information for the Atomic, Molecular and Optical (AMO) Physics Labs at Lehigh University modified from the laser safety program developed by the office of Environmental Health and Safety using the following reference materials: I. American National Standards for Safe Use of Lasers - ANSI Z

  1. Method using laser irradiation for the production of atomically clean crystalline silicon and germanium surfaces

    DOE Patents [OSTI]

    Ownby, Gary W. (Knoxville, TN); White, Clark W. (Oak Ridge, TN); Zehner, David M. (Lenoir City, TN)

    1981-01-01T23:59:59.000Z

    This invention relates to a new method for removing surface impurities from crystalline silicon or germanium articles, such as off-the-shelf p- or n-type wafers to be doped for use as junction devices. The principal contaminants on such wafers are oxygen and carbon. The new method comprises laser-irradiating the contaminated surface in a non-reactive atmosphere, using one or more of Q-switched laser pulses whose parameters are selected to effect melting of the surface without substantial vaporization thereof. In a typical application, a plurality of pulses is used to convert a surface region of an off-the-shelf silicon wafer to an automatically clean region. This can be accomplished in a system at a pressure below 10.sup.-8 Torr, using Q-switched ruby-laser pulses having an energy density in the range of from about 60 to 190 MW/cm.sup.2.

  2. Development of laser excited atomic fluorescence and ionization methods. Final technical progress report, May 1, 1988--December 31, 1991

    SciTech Connect (OSTI)

    Winefordner, J.D.

    1991-12-31T23:59:59.000Z

    Progress report: May 1, 1988 to December 31, 1991. The research supported by DE-FG05-88ER13881 during the past (nearly) 3 years can be divided into the following four categories: (1) theoretical considerations of the ultimate detection powers of laser fluorescence and laser ionization methods; (2) experimental evaluation of laser excited atomic fluorescence; (3) fundamental studies of atomic and molecular parameters in flames and plasmas; (4) other studies.

  3. One-atom correlated-emission laser RID C-6638-2008

    E-Print Network [OSTI]

    Kim, Ho-Joon; Khosa, Ashfaq H.; Lee, Hai-Woong; Zubairy, M. Suhail

    2008-01-01T23:59:59.000Z

    One-atom correlated-emission laser Ho-Joon Kim,1,2 Ashfaq H. Khosa,1 Hai-Woong Lee,1,2 and M. Suhail Zubairy1,3 1Centre for Quantum Physics, COMSATS Institute of Information Technology, Islamabad, Pakistan 2Department of Physics, Korea Advanced...

  4. Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural transformations: Molecular dynamics study

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    Time-resolved diffraction profiles and atomic dynamics in short-pulse laser-induced structural Short pico- and femtosecond pulse laser irradiation has the ability to bring material into a highly dynamics simulations of a 20 nm Au film irradiated with 200 fs laser pulses of different intensity

  5. Four-level atomic interferometer driven by shaped ultrafast laser pulses

    SciTech Connect (OSTI)

    Clow, Stephen; Weinacht, Thomas [Department of Physics, Stony Brook University, Stony Brook, New York 11794 (United States)

    2010-08-15T23:59:59.000Z

    We analyze the behavior of a four-state, two-path atomic interferometer driven by shaped ultrafast laser pulses. The laser pulses interact with atomic rubidium, exciting the atoms to the 5D state via two intermediate resonances (the 5P{sub 1/2} and 5P{sub 3/2}). The relative phase of the two paths can be modified by applying a varying spectral phase at the wavelength corresponding to one of the resonant transitions for each pathway. We trace out the behavior of the system from the simplest case of weak-field excitation with resonant fields to strong-field excitation with a broadband source. Our measurements and analysis reveal that while interference is observed for all field strengths and spectral widths, the character of the interference changes substantially.

  6. Modeling and control of entanglement dynamics in laser cooling of trapped atoms

    E-Print Network [OSTI]

    Maryam Roghani; Heinz-Peter Breuer; Hanspeter Helm

    2011-08-01T23:59:59.000Z

    We discuss the dynamical behavior of the entanglement between the internal and the external degrees of freedom of a trapped atom in electromagnetically-induced transparency (EIT) laser cooling. It is shown that essential features of the intricate entanglement dynamics observed in full numerical simulations of the underlying quantum master equation can be understood in terms of a two-state model on the basis of Landau-Zener splittings in the atom-laser field Hamiltonian. An extension of this model to an effective non-Hermitian Hamiltonian is constructed which describes the decay of entanglement by spontaneous emission processes. We also discuss schemes for the control of entanglement and demonstrate that a permanent entanglement can be imprinted on trapped atoms through a rapid switch off of the driving fields. Finally, we point out fundamental distinctions between the entanglement created in EIT cooling and in the cooling scheme based on velocity-selective coherent population trapping.

  7. Collective Atomic Recoil Laser as a synchronization transition

    E-Print Network [OSTI]

    J. Javaloyes; M. Perrin; A. Politi

    2007-12-11T23:59:59.000Z

    We consider here a model previously introduced to describe the collective behavior of an ensemble of cold atoms interacting with a coherent electromagnetic field. The atomic motion along the self-generated spatially-periodic force field can be interpreted as the rotation of a phase oscillator. This suggests a relationship with synchronization transitions occurring in globally coupled rotators. In fact, we show that whenever the field dynamics can be adiabatically eliminated, the model reduces to a self-consistent equation for the probability distribution of the atomic "phases". In this limit, there exists a formal equivalence with the Kuramoto model, though with important differences in the self-consistency conditions. Depending on the field-cavity detuning, we show that the onset of synchronized behavior may occur through either a first- or second-order phase transition. Furthermore, we find a secondary threshold, above which a periodic self-pulsing regime sets in, that is immediately followed by the unlocking of the forward-field frequency. At yet higher, but still experimentally meaningful, input intensities, irregular, chaotic oscillations may eventually appear. Finally, we derive a simpler model, involving only five scalar variables, which is able to reproduce the entire phenomenology exhibited by the original model.

  8. Steven Chu: Laser Cooling and Trapping of Atoms

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebookScholarshipSpiraling LaserAppropriationsLabAll of us

  9. Laser-assisted free-free transition in electron-atom collisions

    SciTech Connect (OSTI)

    Sinha, C. [Theoretical Physics Department, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700032, West Bengal (India); Bhatia, A. K. [Solar Physics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

    2011-06-15T23:59:59.000Z

    The free-free transition is studied for an electron-hydrogen atom system in the ground state at very low incident energies in the presence of an external homogeneous, monochromatic, and linearly polarized laser field. The incident electron is considered to be dressed by the laser field in a nonperturbative manner by choosing the Volkov solutions in both the initial and final channels. The space part of the scattering wave function for the electron is solved numerically by taking into account the effect of electron-exchange interactions, short-range interactions, as well as of long-range interactions. The laser-assisted differential as well as total elastic cross sections are calculated for single-photon absorption or emission in the soft photon limit, the laser intensity being much less than the atomic field intensity. A strong suppression is noted in the laser-assisted cross sections as compared to the field-free situations. A significant difference is noted in the singlet and the triplet cross sections.

  10. Laser Irradiated Enhancement of the Atomic Electron Capture Rate in search of New Physics

    E-Print Network [OSTI]

    Takaaki Nomura; Joe Sato; Takashi Shimomura

    2007-06-16T23:59:59.000Z

    Electron capture processes are important in the search for new physics. In this context, a high capture rate is desired. We investigate the possibility of enhancing the electron capture rate by irradiating laser beam to ''atom''. The possibility of such enhancement can be understood as a consequence of an enhancement of the electron wave function at the origin, $\\Psi (0)$, through an increased effective mass of the electron. We find that an order of magnitude enhancement can be realized by using a laser with intensity on the order of $10^{10}$ W/mm$^2$ and a photon energy on the order of $10^{-3}$ eV.

  11. Determination of the concentrations of magnesium and aluminum in alloys by laser produced atomic emission spectroscopy

    E-Print Network [OSTI]

    Ashe, William Monroe

    1997-01-01T23:59:59.000Z

    in forensic studies. It would be able to analyze the residue left at a crime scene, or analyze the layers of paint on the ceiling of the Sistine Chapel. ~ It can be used to analyze the ratio of ionic to atomic species ejected by a sample that has been... density per pulse at the focus point of the laser are important. A "short" laser pulse will eject a relatively small amount of material. However, pulses that have a duration on the order of a millisecond can dig deep holes into the sample. In OES a...

  12. Hydrogen-assisted laser-induced resonant transitions between metastable states of antiprotonic helium atoms

    E-Print Network [OSTI]

    Ketzer, B; Von Egidy, T; Maierl, C; Pohl, R; Eades, John; Widmann, E; Yamazaki, T; Kumakura, M; Morita, N; Hayano, R S; Hori, Masaki; Ishikawa, T; Torii, H A; Sugai, I; Horváth, D

    1997-01-01T23:59:59.000Z

    Laser resonance transitions between normally metastable states of antiprotonic helium atoms were observed making use of state dependent quenching effects caused by small admixtures of \\htwo\\ molecules. By selectively shortening the lifetimes of states with higher principal quantum number $n$ as compared to those of lower $n$, this method for the first time provides access to all initially populated metastable states of \\pbar\\hep\\ atoms. This was demonstrated by observing the transitions $(n,l)=(38,l)\\rightarrow (39,l+1),\\ l=35,36,37$ and $(n,l)=(37,l)\\rightarrow (38,l+1),\\ l=34,35,36$.

  13. Crystalline SiGe films grown on Si substrates using laser-assisted plasma-enhanced chemical vapor deposition at low temperature

    SciTech Connect (OSTI)

    Lee, C.-T.; Cheng, J.-H.; Lee, H.-Y. [Institute of Microelectronics, Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China) and Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan, Taiwan 701 (China); Department of Electro-Optical Engineering, National Cheng Kung University, Tainan, Taiwan 701 (China)

    2007-08-27T23:59:59.000Z

    Compared with conventional plasma-enhanced chemical vapor deposition, laser-assisted plasma-enhanced chemical vapor deposition (LAPECVD) can be used to deposit crystalline SiGe films on Si substrates at low temperature. In the LAPECVD system, a CO{sub 2} laser with a wavelength of 10.6 {mu}m was utilized to assist the pyrolytical decomposition of SiH{sub 4} and GeH{sub 4} reactant gases. The resultant Si{sub 0.78}Ge{sub 0.22} films were obtained and verified through the use of the Auger electron spectroscopy measurement. As the diffraction pattern of a glancing incident angle X-ray diffraction measurement had indicated, several significant diffraction peaks corresponding to a diamond-cubic structure at (111) (220), and (311) were clearly observed. Crystalline SiGe films were also identified by the electron diffraction pattern of high-resolution transmission electron microscopy images.

  14. CO-CATALYTIC ABSORPTION LAYERS FOR CONTROLLED LASER-INDUCED CHEMICAL VAPOR DEPOSITION OF CARBON NANOTUBES

    E-Print Network [OSTI]

    Michaelis, F.B.; Weatherup, R.S.; Bayer, B.C.; Bock, M.C.D; Sugime, H.; Caneva, S.; Robertson, J.; Baumberg, J.J.; Hofmann, S.

    2014-02-24T23:59:59.000Z

    ,38 by atomic layer deposition (ALD) using a Cambridge Nanotech Savannah system and a 200°C process with tri[methyl]aluminium and water both carried in a N2(20 sccm) flow for 200 cycles 39,40. Ta layers are sputter deposited (100W, 35sccm Ar, 3.5×10-3 mbar... it is optically compensated). Thermal CVD. CNT growth is also carried out in a custom-built cold-wall CVD chamber with a resistive graphite heater element. Samples are heated to ~670°C and annealed for 5 min in a non-reducing (~10-3 mbar vacuum) or reducing...

  15. Exploring Ramsey-coherent population trapping atomic clock realized with pulsed microwave modulated laser

    SciTech Connect (OSTI)

    Yang, Jing; Yun, Peter [Key Laboratory of Atomic Frequency Standards, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Tian, Yuan; Tan, Bozhong [Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Gu, Sihong, E-mail: shgu@wipm.ac.cn [Key Laboratory of Atomic Frequency Standards, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (China); Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-03-07T23:59:59.000Z

    A scheme for a Ramsey-coherent population trapping (CPT) atomic clock that eliminates the acousto-optic modulator (AOM) is proposed and experimentally studied. Driven by a periodically microwave modulated current, the vertical-cavity surface-emitting laser emits a continuous beam that switches between monochromatic and multichromatic modes. Ramsey-CPT interference has been studied with this mode-switching beam. In eliminating the AOM, which is used to generate pulsed laser in conventional Ramsey-CPT atomic clock, the physics package of the proposed scheme is virtually the same as that of a conventional compact CPT atomic clock, although the resource budget for the electronics will slightly increase as a microwave switch should be added. By evaluating and comparing experimentally recorded signals from the two Ramsey-CPT schemes, the short-term frequency stability of the proposed scheme was found to be 46% better than the scheme with AOM. The experimental results suggest that the implementation of a compact Ramsey-CPT atomic clock promises better frequency stability.

  16. High-Resolved X-ray Spectra of Hollow Atoms in a Femtosecond Laser-Produced Solid Plasma

    E-Print Network [OSTI]

    Umstadter, Donald

    High-Resolved X-ray Spectra of Hollow Atoms in a Femtosecond Laser-Produced Solid Plasma A. Ya and interpreted for the ¢rst time. It is shown that such spectra were generated by multicharged hollow ions-ray spectra of nano- and subnanosecond laser produced plasmas were intensively investigated during the last 20

  17. Effects of free-electron-laser field fluctuations on the frequency response of driven atomic resonances

    E-Print Network [OSTI]

    G. M. Nikolopoulos; P. Lambropoulos

    2012-09-11T23:59:59.000Z

    We study the effects of field fluctuations on the total yields of Auger electrons, obtained in the excitation of neutral atoms to a core-excited state by means of short-wavelength free-electron-laser pulses. Beginning with a self-contained analysis of the statistical properties of fluctuating free-electron-laser pulses, we analyse separately and in detail the cases of single and double Auger resonances, focusing on fundamental phenomena such as power broadening and ac Stark (Autler-Townes) splitting. In certain cases, field fluctuations are shown to influence dramatically the frequency response of the resonances, whereas in other cases the signal obtained may convey information about the bandwidth of the radiation as well as the dipole moment between Auger states.

  18. Laser sustained discharge nozzle apparatus for the production of an intense beam of high kinetic energy atomic species

    DOE Patents [OSTI]

    Cross, J.B.; Cremers, D.A.

    1986-01-10T23:59:59.000Z

    Laser sustained discharge apparatus for the production of intense beams of high kinetic energy atomic species is described. A portion of the plasma resulting from a laser sustained continuous optical discharge which generates energetic atomic species from a gaseous source thereof is expanded through a nozzle into a region of low pressure. The expanded plasma contains a significant concentration of the high kinetic energy atomic species which may be used to investigate the interaction of surfaces therewith. In particular, O-atoms having velocities in excess of 3.5 km/s can be generated for the purpose of studying their interaction with materials in order to develop protective materials for spacecraft which are exposed to such energetic O-atoms during operation in low earth orbit.

  19. Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

    SciTech Connect (OSTI)

    NONE

    1998-02-15T23:59:59.000Z

    A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.

  20. Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons

    SciTech Connect (OSTI)

    Bob Schoenlein

    2009-07-14T23:59:59.000Z

    July 7, 2009 Berkeley Lab summer lecture: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science

  1. Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons

    ScienceCinema (OSTI)

    Bob Schoenlein

    2010-01-08T23:59:59.000Z

    July 7, 2009 Berkeley Lab summer lecture: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science

  2. Bistable Photon Emission from a Solid-State Single-Atom Laser

    E-Print Network [OSTI]

    Neill Lambert; Franco Nori; Christian Flindt

    2015-05-29T23:59:59.000Z

    We predict a dynamical bistability in the photon emission from a solid-state single-atom laser comprised of a microwave cavity coupled to a voltage-biased double quantum dot. The switching rates of the bistability can be extracted from the average electrical current and the shot noise in the quantum dots. Using large-deviation techniques we demonstrate that the full counting statistics of emitted photons is captured by the universal shape of a tilted ellipse whose form can be controlled by modulating the electronic transport in the quantum dots. Our prediction is robust against moderate electronic decoherence and dephasing due to phonons and may be tested using current technology.

  3. Laser Measurements of the Density Shifts of Resonance Lines in Antiprotonic Helium Atoms and Stringent Constraint on the Antiproton Charge and Mass

    E-Print Network [OSTI]

    Torii, H A; Hori, Masaki; Ishikawa, T; Morita, N; Kumakura, M; Sugai, I; Yamazaki, T; Ketzer, B; Hartmann, F J; Von Egidy, T; Pohl, R; Maierl, C; Horváth, D; Eades, John; Widmann, E

    1998-01-01T23:59:59.000Z

    Laser Measurements of the Density Shifts of Resonance Lines in Antiprotonic Helium Atoms and Stringent Constraint on the Antiproton Charge and Mass

  4. 526 OPTICS LETTERS / Vol. 17, No. 7 / April 1, 1992 Improved magneto-optic trapping in a vapor cell

    E-Print Network [OSTI]

    Gibble, Kurt

    to remain proportional to d4, the required laser power must in- crease as d3. Monroe et al.6 have shown-optic trap in a vapor cell and cap- turing atoms in the low-velocity tail of the thermal distribution distribution, which is proportional to v3 for v

  5. Isotropically sensitive optical filter employing atomic resonance transitions

    DOE Patents [OSTI]

    Marling, John B. (Livermore, CA)

    1981-01-01T23:59:59.000Z

    An ultra-high Q isotropically sensitive optical filter or optical detector employing atomic resonance transitions. More specifically, atomic resonance transitions utilized in conjunction with two optical bandpass filters provide an optical detector having a wide field of view (.about.2.pi. steradians) and very narrow acceptance bandwidth approaching 0.01 A. A light signal to be detected is transmitted through an outer bandpass filter into a resonantly absorbing atomic vapor, the excited atomic vapor then providing a fluorescence signal at a different wavelength which is transmitted through an inner bandpass filter. The outer and inner bandpass filters have no common transmission band, thereby resulting in complete blockage of all optical signals that are not resonantly shifted in wavelength by the intervening atomic vapor. Two embodiments are disclosed, one in which the light signal raises atoms contained in the atomic vapor from the ground state to an excited state from which fluorescence occurs, and the other in which a pump laser is used to raise the atoms in the ground state to a first excited state from which the light signal then is resonantly absorbed, thereby raising the atoms to a second excited state from which fluorescence occurs. A specific application is described in which an optical detector according to the present invention can be used as an underwater detector for light from an optical transmitter which could be located in an orbiting satellite.

  6. Breakthrough: X-ray Laser Captures Atoms and Molecules in Action

    ScienceCinema (OSTI)

    Bergmann, Uwe

    2014-05-21T23:59:59.000Z

    The Linac Coherent Light Source at SLAC is the world's most powerful X-ray laser. Just two years after turning on in 2009, breakthrough science is emerging from the LCLS at a rapid pace. A recent experiment used the X-rays to create and probe a 2-million-degree piece of matter in a controlled way for the first time-a significant leap toward understanding the extreme conditions found in the hearts of stars and giant planets, and a finding which could further guide research into nuclear fusion, the mechanism that powers the sun. Upcoming experiments will investigate the fundamental, atomic-scale processes behind such phenomena as superconductivity and magnetism, as well as peering into the molecular workings of photosynthesis in plants.

  7. Breakthrough: X-ray Laser Captures Atoms and Molecules in Action

    SciTech Connect (OSTI)

    Bergmann, Uwe

    2012-04-26T23:59:59.000Z

    The Linac Coherent Light Source at SLAC is the world's most powerful X-ray laser. Just two years after turning on in 2009, breakthrough science is emerging from the LCLS at a rapid pace. A recent experiment used the X-rays to create and probe a 2-million-degree piece of matter in a controlled way for the first time-a significant leap toward understanding the extreme conditions found in the hearts of stars and giant planets, and a finding which could further guide research into nuclear fusion, the mechanism that powers the sun. Upcoming experiments will investigate the fundamental, atomic-scale processes behind such phenomena as superconductivity and magnetism, as well as peering into the molecular workings of photosynthesis in plants.

  8. Optical pumping of a He(2{sup 3}{ital S}) metastable atom beam using a diode laser

    SciTech Connect (OSTI)

    Wallace, C.D.; Bixler, D.L.; Monroe, T.J.; Dunning, F.B.; Walters, G.K. [Department of Physics and the Rice Quantum Institute, Rice University, P. O. Box 1892, Houston, Texas 77251 (United States)] [Department of Physics and the Rice Quantum Institute, Rice University, P. O. Box 1892, Houston, Texas 77251 (United States)

    1995-01-01T23:59:59.000Z

    Use of a commercial 1.083 {mu}m laser diode to optically pump a collimated He (2{sup 3}{ital S}) metastable atom beam is described. Stable, efficient optical pumping is achieved resulting in polarizations that approach 100%. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  9. Coherence properties of Bose-Einstein condensates and atom lasers Wolfgang Ketterle and Hans-Joachim Miesner

    E-Print Network [OSTI]

    Coherence properties of Bose-Einstein condensates and atom lasers Wolfgang Ketterle and Hans of a Bose-Einstein condensate, and summarize the experimental evidence obtained thus far. It is shown that the mean-field energy of a condensate is a measure of second-order coherence. ``Release

  10. Innovative lasers for uranium isotope separation. Final report, September 1, 1989--April 1, 1993

    SciTech Connect (OSTI)

    Brake, M.L.; Gilgenbach, R.M.

    1993-07-01T23:59:59.000Z

    Copper vapor laser have important applications to uranium atomic vapor laser isotope separation (AVLIS). We have investigated two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated in three separate experimental configurations. The first examined the application of CW (0-500W) power and was found to be an excellent method for producing an atomic copper vapor from copper chloride. The second used a pulsed (5kW, 0.5--5 kHz) signal superimposed on the CW signal to attempt to produce vaporization, dissociation and excitation to the laser states. Enhanced emission of the optical radiation was observed but power densities were found to be too low to achieve lasing. In a third experiment we attempted to increase the applied power by using a high power magnetron to produce 100 kW of pulsed power. Unfortunately, difficulties with the magnetron power supply were encountered leaving inconclusive results. Detailed modeling of the electromagnetics of the system were found to match the diagnostics results well. An electron beam pumped copper vapor system (350 kV, 1.0 kA, 300 ns) was investigated in three separate copper chloride heating systems, external chamber, externally heated chamber and an internally heated chamber. Since atomic copper spectral lines were not observed, it is assumed that a single pulse accelerator is not capable of both dissociating the copper chloride and exciting atomic copper and a repetitively pulsed electron beam generator is needed.

  11. Electron-ion dynamics in laser-assisted desorption of hydrogen atoms from H-Si(111) surface

    SciTech Connect (OSTI)

    Bubin, Sergiy; Varga, Kalman [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)

    2011-09-15T23:59:59.000Z

    In the framework of real time real space time-dependent density functional theory we have studied the electron-ion dynamics of a hydrogen-terminated silicon surface H-Si(111) subjected to intense laser irradiation. Two surface fragments of different sizes have been used in the simulations. When the intensity and duration of the laser exceed certain levels (which depend on the wavelength) we observe the desorption of the hydrogen atoms, while the underlying silicon layer remains essentially undamaged. Upon further increase of the laser intensity, the chemical bonds between silicon atoms break as well. The results of the simulations suggest that with an appropriate choice of laser parameters it should be possible to remove the hydrogen layer from the H-Si(111) surface in a matter of a few tens of femtoseconds. We have also observed that at high laser field intensities (2-4 V/A in this work) the desorption occurs even when the laser frequency is smaller than the optical gap of the silicon surface fragments. Therefore, nonlinear phenomena must play an essential role in such desorption processes.

  12. Interaction of wide-band-gap single crystals with 248-nm excimer laser radiation. XI. The effect of water vapor and temperature on laser desorption

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    . Significantly, introducing water vapor lowers the particle velocities and thus the effective surface temperature systems, simultaneous electronic excitation and exposure to aggressive chemicals can acceler- ate etching-induced neutral particle desorption and surface erosion on single- crystal sodium chloride in the presence of low

  13. Quantum cascade laser investigations of CH{sub 4} and C{sub 2}H{sub 2} interconversion in hydrocarbon/H{sub 2} gas mixtures during microwave plasma enhanced chemical vapor deposition of diamond

    SciTech Connect (OSTI)

    Ma Jie; Cheesman, Andrew; Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Hay, Kenneth G.; Wright, Stephen; Langford, Nigel; Duxbury, Geoffrey [Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG (United Kingdom); Mankelevich, Yuri A. [Skobel'tsyn Institute of Nuclear Physics, Moscow State University, Leninskie Gory, Moscow 119991 (Russian Federation)

    2009-08-01T23:59:59.000Z

    CH{sub 4} and C{sub 2}H{sub 2} molecules (and their interconversion) in hydrocarbon/rare gas/H{sub 2} gas mixtures in a microwave reactor used for plasma enhanced diamond chemical vapor deposition (CVD) have been investigated by line-of-sight infrared absorption spectroscopy in the wavenumber range of 1276.5-1273.1 cm{sup -1} using a quantum cascade laser spectrometer. Parameters explored include process conditions [pressure, input power, source hydrocarbon, rare gas (Ar or Ne), input gas mixing ratio], height (z) above the substrate, and time (t) after addition of hydrocarbon to a pre-existing Ar/H{sub 2} plasma. The line integrated absorptions so obtained have been converted to species number densities by reference to the companion two-dimensional (r,z) modeling of the CVD reactor described in Mankelevich et al. [J. Appl. Phys. 104, 113304 (2008)]. The gas temperature distribution within the reactor ensures that the measured absorptions are dominated by CH{sub 4} and C{sub 2}H{sub 2} molecules in the cool periphery of the reactor. Nonetheless, the measurements prove to be of enormous value in testing, tensioning, and confirming the model predictions. Under standard process conditions, the study confirms that all hydrocarbon source gases investigated (methane, acetylene, ethane, propyne, propane, and butane) are converted into a mixture dominated by CH{sub 4} and C{sub 2}H{sub 2}. The interconversion between these two species is highly dependent on the local gas temperature and the H atom number density, and thus on position within the reactor. CH{sub 4}->C{sub 2}H{sub 2} conversion occurs most efficiently in an annular shell around the central plasma (characterized by 1400CH{sub 4} is favored in the more distant regions where T{sub gas}<1400 K. Analysis of the multistep interconversion mechanism reveals substantial net consumption of H atoms accompanying the CH{sub 4}->C{sub 2}H{sub 2} conversion, whereas the reverse C{sub 2}H{sub 2}->CH{sub 4} process only requires H atoms to drive the reactions; H atoms are not consumed by the overall conversion.

  14. Image Storage in Hot Vapors

    E-Print Network [OSTI]

    L. Zhao; T. Wang; Y. Xiao; S. F. Yelin

    2007-10-22T23:59:59.000Z

    We theoretically investigate image propagation and storage in hot atomic vapor. A $4f$ system is adopted for imaging and an atomic vapor cell is placed over the transform plane. The Fraunhofer diffraction pattern of an object in the object plane can thus be transformed into atomic Raman coherence according to the idea of ``light storage''. We investigate how the stored diffraction pattern evolves under diffusion. Our result indicates, under appropriate conditions, that an image can be reconstructed with high fidelity. The main reason for this procedure to work is the fact that diffusion of opposite-phase components of the diffraction pattern interfere destructively.

  15. Room-temperature cw operation of InGaP/InGaAlP visible light laser diodes on GaAs substrates grown by metalorganic chemical vapor deposition

    SciTech Connect (OSTI)

    Ishikawa, M.; Ohba, Y.; Sugawara, H.; Yamamoto, M.; Nakanisi, T.

    1986-01-20T23:59:59.000Z

    Room-temperature cw operation for InGaP/InGaAlP double heterostructure (DH) laser diodes on GaAs substrates was achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapor deposition using methyl metalorganics. A lasing wavelength of 679 nm and a threshold current of 109 mA at 24C were obtained for an inner stripe structure laser diode with a 250- m-long and 7- m stripe geometry. The laser operated at up to 51C. The characteristic temperature T0 was 87 K at around room temperature. The lowest threshold current density, 5.0 kA/cmS, was obtained with a 20- m stripe width laser diode under room-temperature pulsed operation.

  16. Interferences of real trajectories and the emergence of quantum features in electron-atom scattering in a strong laser field

    SciTech Connect (OSTI)

    Cerkic, A. [Federal Meteorological Institute, Bardakcije 12, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2006-03-15T23:59:59.000Z

    Using the example of electron-atom scattering in a strong laser field, it is shown that the oscillatory structure of the scattered electron spectrum can be explained as a consequence of the interference of the real electron trajectories in terms of Feynman's path integral. While in previous work on quantum-orbit theory the complex solutions of the saddle-point equations were considered, we show here that for the electron-atom scattering with much simpler real solutions a satisfactory agreement with the strong-field-approximation results can be achieved. Real solutions are applicable both for the direct (low-energy) and the rescattering (high-energy) plateau in the scattered electron spectrum. In between the plateaus and beyond the rescattering cutoff good results can be obtained using the complex (quantum) solutions and the uniform approximation. The interference of real solutions is related to the recent attosecond double-slit experiment in time.

  17. Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons (LBNL Summer Lecture Series)

    SciTech Connect (OSTI)

    Schoenlein, Robert (Deputy Director, Advanced Light Source) [Deputy Director, Advanced Light Source

    2009-07-07T23:59:59.000Z

    Summer Lecture Series 2009: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science.

  18. Using Lasers and X-rays to Reveal the Motion of Atoms and Electrons (LBNL Summer Lecture Series)

    ScienceCinema (OSTI)

    Schoenlein, Robert [Deputy Director, Advanced Light Source

    2011-04-28T23:59:59.000Z

    Summer Lecture Series 2009: The ultrafast motion of atoms and electrons lies at the heart of chemical reactions, advanced materials with exotic properties, and biological processes such as the first event in vision. Bob Schoenlein, Deputy Director for Science at the Advanced Light Source, will discuss how such processes are revealed by using laser pulses spanning a millionth of a billionth of a second, and how a new generation of light sources will bring the penetrating power of x-rays to the world of ultrafast science.

  19. Laser frequency stabilization to highly excited state transitions using electromagnetically induced transparency in a cascade system

    E-Print Network [OSTI]

    R. P. Abel; A. K. Mohapatra; M. G. Bason; J. D. Pritchard; K. J. Weatherill; U. Raitzsch; C. S. Adams

    2009-03-05T23:59:59.000Z

    We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency (EIT). Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D2 transition and a second laser to a transition from the intermediate state to a Rydberg state with principal quantum number n=19 - 70. A combined laser linewidth of 280 kHz over a 0.1 ms time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of strong optical transitions.

  20. Observation of double resonant laser induced transitions in the $v = n - l - 1 = 2$ metastable cascade of antiprotonic helium-4 atoms

    E-Print Network [OSTI]

    Hayano, R S; Tamura, H; Torii, H A; Hori, Masaki; Maas, F E; Morita, N; Kumakura, M; Sugai, I; Hartmann, F J; Daniel, H; Von Egidy, T; Ketzer, B; Pohl, R; Horváth, D; Eades, John; Widmann, E; Yamazaki, T

    1997-01-01T23:59:59.000Z

    A new laser-induced resonant transition in the $v=n-l-1=2$ metastable cascade of antiprotonic $^4$He atoms has been found by using a double resonance technique. This was done by setting the first laser to the already known 470.724 nm resonance ($(n,l)=(37,34)\\rightarrow (36,33)$), while the $(38,35)\\rightarrow (37,34)$ transition was searched for with the second laser. The resonant transition was found at wavelength of 529.622$\\pm$0.003 nm, showing excellent agreement with a recent prediction of Korobov.

  1. Effect of Induced Spin-Orbit Coupling for Atoms via Laser Fields

    E-Print Network [OSTI]

    Xiong-Jun Liu; Mario F. Borunda; Xin Liu; Jairo Sinova

    2008-11-17T23:59:59.000Z

    We propose an experimental scheme to study spin-orbit coupling effects in a of two-dimensional (2D) Fermi atomic gas cloud by coupling its internal electronic states (pseudospins) to radiation in a delta configuration. The induced spin-orbit coupling can be of the Dresselhaus and Rashba type with and without a Zeeman term. We show that the optically induced spin-orbit coupling can lead to a spin-dependent effective mass under appropriate condition, with one of them able to be tuned between positive and negative effective mass. As a direct observable we show that in the expansion dynamics of the atomic cloud the initial atomic cloud splits into two clouds for the positive effective mass case regime, and into four clouds for the negative effective mass regime.

  2. Frequency response of an atomic resonance driven by weak free-electron-laser fluctuating pulses

    E-Print Network [OSTI]

    G M Nikolopoulos; P Lambropoulos

    2014-01-20T23:59:59.000Z

    Motivated by recent experiments pertaining to the interaction of weak SASE-FEL pulses with atoms and molecules, we investigate the conditions under which such interactions can be described in the framework of a simple phase-diffusion model with decorrelated atom-field dynamics. The nature of the fluctuations that are inevitably present in SASE-FEL pulses is shown to play a pivotal role in the success of the decorrelation. Our analysis is performed in connection with specific recent experimental results from FLASH in the soft X-ray regime.

  3. Variable emissivity laser thermal control system

    DOE Patents [OSTI]

    Milner, Joseph R. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  4. Comparative investigation of third- and fifth-harmonic generation in atomic and molecular gases driven by midinfrared ultrafast laser pulses

    SciTech Connect (OSTI)

    Ni Jielei; Yao Jinping; Zeng Bin; Chu Wei; Li Guihua; Zhang Haisu; Jing Chenrui [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Chin, S. L. [Department of Physics, Engineering Physics and Optics, and Center for Optics, Photonics and Laser (COPL), Laval University, Laval, Quebec, G1K 7P4 (Canada); Cheng, Y.; Xu, Z. [State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, P.O. Box 800-211, Shanghai 201800 (China)

    2011-12-15T23:59:59.000Z

    We report on the comparative experimental investigation on third- and fifth-harmonic generation (THG and FHG) in atomic and molecular gases driven by midinfrared ultrafast laser pulses at a wavelength of {approx}1500 nm. We observe that the conversion efficiencies of both the THG and FHG processes saturate at similar peak intensities close to {approx}1.5 x 10{sup 14} W/cm{sup 2} for argon, nitrogen, and air, whose ionization potentials are close to each other. Near the saturation intensity, the ratio of yields of the FHG and THG reaches {approx}10{sup -1} for all the gases. Our results show that high-order Kerr effect seems to exist; however, contribution from the fourth-order Kerr refractive index coefficient alone is insufficient to balance the Kerr self-focusing without the assistance of plasma generation.

  5. Bose-Einstein condensation of a system of two-level atoms in resonant interaction with a single-running-wave-mode laser field 

    E-Print Network [OSTI]

    Wang, Xinfeng

    2001-01-01T23:59:59.000Z

    In this thesis, we study the influence of a single-running-wave-mode laser field to the critical temperature T[] of Bose-Einstein condensation(BEC) of a system of two-level bosonic atoms. Using a simple model, we obtain the dispersion relation...

  6. Laser-induced resonant transitions in the v=n-l-1=2 and 3 metastable cascades of antiprotonic $^{3}He atoms

    E-Print Network [OSTI]

    Torii, H A; Ishikawa, T; Maas, F E; Hayano, R S; Morita, N; Kumakura, M; Sugai, I; Ketzer, B; Daniel, H; Hartmann, F J; Pohl, R; Schmidt, R; Von Egidy, T; Horváth, D; Eades, John; Widmann, E; Yamazaki, T

    1996-01-01T23:59:59.000Z

    Laser-induced resonant transitions in metastable antiprotonic ^3He atoms have been found. The observed transitions at wavelengths 593.388 \\pm 0.001~nm and at 463.947 \\pm 0.002~nm have been respectively ascribed to the (n,l)~=~(38,34)\\,\\rightarrow\\,(37,33) and the (36 33)\\,\\rightarrow\\,(35,32) transitions.

  7. High passive-stability diode-laser design for use in atomic-physics experiments

    E-Print Network [OSTI]

    Cook, Eryn C; Brown-Heft, Tobias L; Garman, Jeffrey C; Steck, Daniel A

    2012-01-01T23:59:59.000Z

    We present the design and performance characterization of an external cavity diode-laser system optimized for high stability, low passive spectral linewidth, low cost, and ease of in-house assembly. The main cavity body is machined from a single aluminum block for robustness to temperature changes and mechanical vibrations, and features a stiff and light diffraction-grating arm to suppress low-frequency mechanical resonances. The cavity is vacuum-sealed, and a custom-molded silicone external housing further isolates the system from acoustic noise and temperature fluctuations. Beam shaping, optical isolation, and fiber coupling are integrated, and the design is easily adapted to many commonly used wavelengths. Resonance data, passive-linewidth data, and passive stability characterization of the new design demonstrate that its performance exceeds published specifications for commercial precision diode-laser systems. The design is fully documented and freely available.

  8. Measuring molecular electric dipoles using trapped atomic ions and ultrafast laser pulses

    E-Print Network [OSTI]

    Jordi Mur-Petit; Juan José García-Ripoll

    2015-01-12T23:59:59.000Z

    We study a hybrid quantum system composed of an ion and an electric dipole. We show how a trapped ion can be used to measure the small electric field generated by a classical dipole. We discuss the application of this scheme to measure the electric dipole moment of cold polar molecules, whose internal state can be controlled with ultrafast laser pulses, by trapping them in the vicinity of a trapped ion.

  9. Ultrafast laser control of backward superfluorescence towards standoff sensing

    SciTech Connect (OSTI)

    Ariunbold, Gombojav O. [Texas A and M University, College Station, Texas 77843 (United States); National University of Mongolia, Ulaanbaatar 210646 (Mongolia); Baylor University, Waco, Texas 76798 (United States); Sautenkov, Vladimir A. [Texas A and M University, College Station, Texas 77843 (United States); Joint Institute for High Temperatures, Russian Academy of Sciences, Moscow 125412 (Russian Federation); P. N. Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Rostovtsev, Yuri V. [University of North Texas, Denton, Texas 76203 (United States); Scully, Marlan O. [Texas A and M University, College Station, Texas 77843 (United States); Baylor University, Waco, Texas 76798 (United States); Princeton University, Princeton, New Jersey 08544 (United States)

    2014-01-13T23:59:59.000Z

    We study infrared backward cooperative emission in a rubidium vapor induced by ultrafast two-photon optical excitations. The laser coherent control of the backward emission is demonstrated by using a pair of 100 fs pulses with a variable time delay. The temporal variation (quantum beat) of the backward beam intensity due to interference of atomic transitions in the rubidium atomic level system 5S-5P-5D is produced and controlled. Based on the obtained experimental results, we discuss possible applications of the developed approach for creation of an effective “guide star” in the sodium atomic layer in the upper atmosphere (mesosphere)

  10. Sub-Doppler resonances in the back-scattered light from random porous media infused with Rb vapor

    E-Print Network [OSTI]

    Villalba, S; Lenci, L; Bloch, D; Lezama, A; Failache, H

    2013-01-01T23:59:59.000Z

    We report on the observation of sub-Doppler resonances on the back-scattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and the back-scattered light probes it. Some specificities of the observed spectra reflect the transient atomic evolution under confinement inside the pores. Simplicity, robustness and potential miniaturization are appealing features of this system as a spectroscopic reference.

  11. Determination of transient atomic structure of laser-excited materials from time-resolved diffraction data

    SciTech Connect (OSTI)

    Giret, Yvelin [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan) [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom); Naruse, Nobuyasu; Murooka, Yoshie; Yang, Jinfeng; Tanimura, Katsumi [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan)] [The Institute of Scientific and Industrial Research (ISIR), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Daraszewicz, Szymon L.; Duffy, Dorothy M.; Shluger, Alexander L. [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom)] [Department of Physics and Astronomy, University College London, Gower Street, WC1E 6BT London (United Kingdom)

    2013-12-16T23:59:59.000Z

    The time evolution of the Bragg peaks of photo-excited gold nanofilms is measured using transmission ultrafast electron diffraction (UED) with 3.0 MeV electron pulses and the corresponding structure evolution is calculated using two-temperature molecular dynamics (2T-MD). The good agreement obtained between the measured and calculated Bragg peaks, over the full experimental timescale, enables the lattice temperature effects and the structural changes to be disentangled for the first time. The agreement demonstrates that 2T-MD is a reliable method for solving the inverse problem of structure determination of laser irradiated metals in UED measurements.

  12. Optical atomic magnetometer

    DOE Patents [OSTI]

    Budker, Dmitry; Higbie, James; Corsini, Eric P

    2013-11-19T23:59:59.000Z

    An optical atomic magnetometers is provided operating on the principles of nonlinear magneto-optical rotation. An atomic vapor is optically pumped using linearly polarized modulated light. The vapor is then probed using a non-modulated linearly polarized light beam. The resulting modulation in polarization angle of the probe light is detected and used in a feedback loop to induce self-oscillation at the resonant frequency.

  13. Beyond the single-atom response in absorption lineshapes: Probing a dense, laser-dressed helium gas with attosecond pulse trains

    E-Print Network [OSTI]

    Liao, Chen-Ting; Camp, Seth; Schafer, Kenneth J; Gaarde, Mette B

    2015-01-01T23:59:59.000Z

    We investigate the absorption line shapes of laser-dressed atoms beyond the single-atom response, by using extreme ultraviolet (XUV) attosecond pulse trains to probe an optically thick helium target under the influence of a strong infrared (IR) field. We study the interplay between the IR-induced phase shift of the microscopic time-dependent dipole moment and the resonant-propagation-induced reshaping of the macroscopic XUV pulse. Our experimental and theoretical results show that as the optical depth increases, this interplay leads initially to a broadening of the IR-modified line shape, and subsequently to the appearance of new, narrow features in the absorption line.

  14. Safety approaches for high power modular laser operation

    SciTech Connect (OSTI)

    Handren, R.T.

    1993-03-01T23:59:59.000Z

    Approximately 20 years ago, a program was initiated at the Lawrence Livermore National Laboratory (LLNL) to study the feasibility of using lasers to separate isotopes of uranium and other materials. Of particular interest has been the development of a uranium enrichment method for the production of commercial nuclear power reactor fuel to replace current more expensive methods. The Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) Program has progressed to the point where a plant-scale facility to demonstrate commercial feasibility has been built and is being tested. The U-AVLIS Program uses copper vapor lasers which pump frequency selective dye lasers to photoionize uranium vapor produced by an electron beam. The selectively ionized isotopes are electrostatically collected. The copper lasers are arranged in oscillator/amplifier chains. The current configuration consists of 12 chains, each with a nominal output of 800 W for a system output in excess of 9 kW. The system requirements are for continuous operation (24 h a day, 7 days a week) and high availability. To meet these requirements, the lasers are designed in a modular form allowing for rapid change-out of the lasers requiring maintenance. Since beginning operation in early 1985, the copper lasers have accumulated over 2 million unit hours at a >90% availability. The dye laser system provides approximately 2.5 kW average power in the visible wavelength range. This large-scale laser system has many safety considerations, including high-power laser beams, high voltage, and large quantities ({approximately}3000 gal) of ethanol dye solutions. The Laboratory`s safety policy requires that safety controls be designed into any process, equipment, or apparatus in the form of engineering controls. Administrative controls further reduce the risk to an acceptable level. Selected examples of engineering and administrative controls currently being used in the U-AVLIS Program are described.

  15. Doppler- and recoil-free laser excitation of Rydberg states via three-photon transitions

    SciTech Connect (OSTI)

    Ryabtsev, I. I.; Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospekt Lavrentyeva 13, 630090 Novosibirsk (Russian Federation)

    2011-11-15T23:59:59.000Z

    Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a starlike geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a particular laser excitation scheme 5S{sub 1/2}{yields}5P{sub 3/2}{yields}6S{sub 1/2}{yields}nP in Rb atoms have shown that, compared to the one- and two-photon laser excitation, this approach provides much narrower linewidth and longer coherence time for both cold atom samples and hot vapors, if the intermediate one-photon resonances of the three-photon transition are detuned by more than respective single-photon Doppler widths. This method can be used to improve fidelity of Rydberg quantum gates and precision of spectroscopic measurements in Rydberg atoms.

  16. Cold molecules formation by shaping with light the short-range interaction between cold atoms: photoassociation with strong laser pulses

    E-Print Network [OSTI]

    M. Vatasescu

    2009-06-10T23:59:59.000Z

    The paper investigates cold molecules formation in the photoassociation of two cold atoms by a strong laser pulse applied at short interatomic distances, which lead to a molecular dynamics taking place in the light-induced (adiabatic) potentials. A two electronic states model in the cesium dimer is used to analyse the effects of this strong coupling regime and to show specific results: i) acceleration of the ground state population to the inner zone due to a non-impulsive regime of coupling at short and intermediate interatomic distances; ii) formation of cold molecules in strongly bound levels of the ground state, where the population at the end of the pulse is much bigger than the population photoassociated in bound levels of the excited state; iii) the final momentum distribution of the ground state wavepacket keeping the signatures of the maxima in the initial wavefunction continuum. It is shown that the topology of the light-induced potentials plays an important role in dynamics.

  17. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  18. Calibrated vapor generator source

    DOE Patents [OSTI]

    Davies, John P. (Idaho Falls, ID); Larson, Ronald A. (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Hall, Harold J. (Idaho Falls, ID); Stoddard, Billy D. (Idaho Falls, ID); Davis, Sean G. (Idaho Falls, ID); Kaser, Timothy G. (Idaho Falls, ID); Conrad, Frank J. (Albuquerque, NM)

    1995-01-01T23:59:59.000Z

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  19. Isotope Enrichment Detection by Laser Ablation - Dual Tunable Diode Laser Absorption Spectrometry

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2009-07-01T23:59:59.000Z

    The rapid global expansion of nuclear energy is motivating the expedited development of new safeguards technology to mitigate potential proliferation threats arising from monitoring gaps within the uranium enrichment process. Current onsite enrichment level monitoring methods are limited by poor sensitivity and accuracy performance. Offsite analysis has better performance, but this approach requires onsite hand sampling followed by time-consuming and costly post analysis. These limitations make it extremely difficult to implement comprehensive safeguards accounting measures that can effectively counter enrichment facility misuse. In addition, uranium enrichment by modern centrifugation leads to a significant proliferation threat, since the centrifuge cascades can quickly produce a significant quantity of highly enriched uranium (HEU). The Pacific Northwest National Laboratory is developing an engineered safeguards approach having continuous aerosol particulate collection and uranium isotope analysis to provide timely detection of HEU production in a low enriched uranium facility. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy, to characterize the 235U/238U isotopic ratio by subtle differences in atomic absorption wavelengths arising from differences in each isotope’s nuclear mass, volume, and spin (hyperfine structure for 235U). Environmental sampling media is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes a 10 to 20-µm sample diameter. The ejected plasma forms a plume of atomic vapor. A plume for a sample containing uranium has atoms of the 235U and 238U isotopes present. Tunable diode lasers are directed through the plume to selectively excite each isotope and their presence is detected by monitoring absorbance signals on a shot-to-shot basis. Single-shot detection sensitivity approaching the femtogram range and abundance uncertainty less than 10% have been demonstrated with measurements on surrogate materials. In this paper we present measurement results on samples containing background materials (e.g., dust, minerals, soils) laced with micron-sized target particles having isotopic ratios ranging from 1 to 50%.

  20. Coherent cooling of atoms in a frequency-modulated standing laser wave: Wave function and stochastic trajectory approaches

    SciTech Connect (OSTI)

    Argonov, V. Yu., E-mail: argonov@poi.dvo.ru [Russian Academy of Sciences, Pacific Oceanological Institute (Russian Federation)

    2014-11-15T23:59:59.000Z

    The wave function of a moderately cold atom in a stationary near-resonant standing light wave delocalizes very fast due to wave packet splitting. However, we show that frequency modulation of the field can suppress packet splitting for some atoms whose specific velocities are in a narrow range. These atoms remain localized in a small space for a long time. We demonstrate and explain this effect numerically and analytically. We also demonstrate that the modulated field can not only trap but also cool the atoms. We perform a numerical experiment with a large atomic ensemble having wide initial velocity and energy distributions. During the experiment, most of atoms leave the wave while the trapped atoms have a narrow energy distribution.

  1. Optical Precursors in Rubidium Vapor and Their Relation to Superradiance

    E-Print Network [OSTI]

    Yang, Wenlong

    2012-10-19T23:59:59.000Z

    Optical precursor is the sharp optical pulse front that does not show delay in absorptive media. In this thesis, optical precursor behavior in rubidium (Rb) vapor was investigated in the picoseconds regime. An amplified femtosecond laser was shaped...

  2. Atomic magnetometer

    DOE Patents [OSTI]

    Schwindt, Peter (Albuquerque, NM); Johnson, Cort N. (Albuquerque, NM)

    2012-07-03T23:59:59.000Z

    An atomic magnetometer is disclosed which uses a pump light beam at a D1 or D2 transition of an alkali metal vapor to magnetically polarize the vapor in a heated cell, and a probe light beam at a different D2 or D1 transition to sense the magnetic field via a polarization rotation of the probe light beam. The pump and probe light beams are both directed along substantially the same optical path through an optical waveplate and through the heated cell to an optical filter which blocks the pump light beam while transmitting the probe light beam to one or more photodetectors which generate electrical signals to sense the magnetic field. The optical waveplate functions as a quarter waveplate to circularly polarize the pump light beam, and as a half waveplate to maintain the probe light beam linearly polarized.

  3. ATOMIC PHYSICS DMITRY BUDKER | DEREK F. KIMBALL | DAVID P. DEMILLE

    E-Print Network [OSTI]

    Pines, Alexander

    symmetries, atomic magnetometers and frequency comb metrology with ultra-short laser pulses. Dmitry Budker

  4. Solid-state source of atomic oxygen for low-temperature oxidation processes: Application to pulsed laser deposition of TiO{sub 2}:N films

    SciTech Connect (OSTI)

    Ojima, Daiki; Chiba, Tetsuya; Shima, Kazunari; Hiramatsu, Hidenori; Hosono, Hideo; Hayashi, Katsuro [Materials and Structures Laboratory, Tokyo Institute of Technology, R3-34, Nagatsuta 4259, Yokohama 226-8503 (Japan)

    2012-02-15T23:59:59.000Z

    An atomic oxygen (AO) source has been redesigned to coordinate with a pulsed laser deposition system and used to grow nitrogen-doped TiO{sub 2} films by deposition of TiN and simultaneous irradiation of the substrate with AO. The AO source uses an incandescently heated thin tube of zirconia as an oxygen permeation media to generate pure AO of low kinetic energy. The emission flux is calibrated using a silver-coated quartz crystal microbalance. The thin shape of the probe and transverse emission geometry of this emission device allow the emission area to be positioned close to the substrate surface, enhancing the irradiation flux at the substrate. AO irradiation is crucial for formation of TiO{sub 2} phases via oxidation of the deposited TiN laser plume, and is effective for decrease of the substrate temperature for crystallization of anatase phase to as low as around 200 deg. C.

  5. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neturons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

  6. Nuclear reactivity control using laser induced polarization

    DOE Patents [OSTI]

    Bowman, Charles D. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    A control element for reactivity control of a fission source provides an atomic density of .sup.3 He in a control volume which is effective to control criticality as the .sup.3 He is spin-polarized. Spin-polarization of the .sup.3 He affects the cross section of the control volume for fission neutrons and hence, the reactivity. An irradiation source is directed within the .sup.3 He for spin-polarizing the .sup.3 He. An alkali-metal vapor may be included with the .sup.3 He where a laser spin-polarizes the alkali-metal atoms which in turn, spin-couple with .sup.3 He to spin-polarize the .sup.3 He atoms.

  7. High-Precision Structural Studies of the Antiproton Helium Atom $\\overline{p}^{4}He^+$ by Observing Laser Resonances with $\\Delta v = \\Delta (n-l-1) = 2$

    E-Print Network [OSTI]

    Yamazaki, T; Eades, John; Kumakura, M; Morita, N; Torii, H A; Hori, Masaki; Ishikawa, T; Maas, F E; Tamura, H; Hayano, R S; Sugai, I; Fujita, Y; Ketzer, B; Daniel, H; Hartmann, F J; Hasinoff, M D; Pohl, R; Schmidt, R; Von Egidy, T; Horváth, D

    1997-01-01T23:59:59.000Z

    Very weak laser resonances of unfavoured transitions $(n,l) \\rightarrow (n+1,l-1)$ have been observed in metastable \\={p}$^4$He$^+$ atoms by using a pulsed antiproton beam. The observed wavelengths (713.578 $\\pm$ 0.006 nm for $l$ = 34 and 726.095 $\\pm$ 0.004 nm for $l$ = 35), as well as those of the known favoured transitions, are to a few ppm accounted for by a recent variational calculation of Korobov, which includes the relativistic correction.

  8. Integration of the AVLIS (atomic vapor laser isotopic separation) process into the nuclear fuel cycle. [Effect of AVLIS feed requirements on overall fuel cycle

    SciTech Connect (OSTI)

    Hargrove, R.S.; Knighton, J.B.; Eby, R.S.; Pashley, J.H.; Norman, R.E.

    1986-08-01T23:59:59.000Z

    AVLIS RD and D efforts are currently proceeding toward full-scale integrated enrichment demonstrations in the late 1980's and potential plant deployment in the mid 1990's. Since AVLIS requires a uranium metal feed and produces an enriched uranium metal product, some change in current uranium processing practices are necessitated. AVLIS could operate with a UF/sub 6/-in UF/sub 6/-out interface with little effect to the remainder of the fuel cycle. This path, however, does not allow electric utility customers to realize the full potential of low cost AVLIS enrichment. Several alternative processing methods have been identified and evaluated which appear to provide opportunities to make substantial cost savings in the overall fuel cycle. These alternatives involve varying levels of RD and D resources, calendar time, and technical risk to implement and provide these cost reduction opportunities. Both feed conversion contracts and fuel fabricator contracts are long-term entities. Because of these factors, it is not too early to start planning and making decisions on the most advantageous options so that AVLIS can be integrated cost effectively into the fuel cycle. This should offer economic opportunity to all parties involved including DOE, utilities, feed converters, and fuel fabricators. 10 refs., 11 figs., 2 tabs.

  9. Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

    SciTech Connect (OSTI)

    Venkatraman, V.; Kang, S.; Affolderbach, C.; Mileti, G., E-mail: gaetano.mileti@unine.ch [Laboratoire Temps-Fréquence, University of Neuchâtel, Neuchâtel 2000 (Switzerland); Shea, H. [Microsystems for Space Technologies Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel 2002 (Switzerland)

    2014-02-03T23:59:59.000Z

    Miniature (vapor-cell based devices using optical pumping of alkali atoms, such as atomic clocks and magnetometers, today mostly employ vertical-cavity surface-emitting lasers as pump light sources. Here, we report on the demonstration of optical pumping in a microfabricated alkali vapor resonance cell using (1) a microfabricated Rb discharge lamp light source, as well as (2) a conventional glass-blown Rb discharge lamp. The microfabricated Rb lamp cell is a dielectric barrier discharge (DBD) light source, having the same inner cell volume of around 40?mm{sup 3} as that of the resonance cell, both filled with suitable buffer gases. A miniature (?2?cm{sup 3} volume) test setup based on the M{sub z} magnetometer interrogation technique was used for observation of optical-radiofrequency double-resonance signals, proving the suitability of the microfabricated discharge lamp to introduce efficient optical pumping. The pumping ability of this light source was found to be comparable to or even better than that of a conventional glass-blown lamp. The reported results indicate that the micro-fabricated DBD discharge lamp has a high potential for the development of a new class of miniature atomic clocks, magnetometers, and quantum sensors.

  10. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    SciTech Connect (OSTI)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T.

    1994-10-01T23:59:59.000Z

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of uranium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed.

  11. Evaporation monitoring and composition control of alloy systems with widely differing vapor pressures

    SciTech Connect (OSTI)

    Anklam, T.M.; Berzins, L.V.; Braun, D.G.; Haynam, C.; McClelland, M.A.; Meier, T. [Lawrence Livermore National Lab., CA (United States)

    1994-12-31T23:59:59.000Z

    Lawrence Livermore National Laboratory is developing sensors and controls to improve and extend electron beam materials processing technology to alloy systems with constituents of widely varying vapor pressure. The approach under development involves using tunable lasers to measure the density and composition of the vapor plume. A laser based vaporizer control system for vaporization of a uranium-iron alloy has been previously demonstrated in multi-hundred hour, high rate vaporization experiments at LLNL. This paper reviews the design and performance of the uranium vaporization sensor and control system and discusses the extension of the technology to monitoring of titanium vaporization. Data is presented from an experiment in which titanium wire was fed into a molten niobium pool. Laser data is compared to deposited film composition and film cross sections. Finally, the potential for using this technique for composition control in melting applications is discussed.

  12. Laser damage properties of TiO{sub 2}/Al{sub 2}O{sub 3} thin films grown by atomic layer deposition

    SciTech Connect (OSTI)

    Wei Yaowei; Liu Hao; Sheng Ouyang; Liu Zhichao; Chen Songlin; Yang Liming

    2011-08-20T23:59:59.000Z

    Research on thin film deposited by atomic layer deposition (ALD) for laser damage resistance is rare. In this paper, it has been used to deposit TiO{sub 2}/Al{sub 2}O{sub 3} films at 110 deg. C and 280 deg. C on fused silica and BK7 substrates. Microstructure of the thin films was investigated by x-ray diffraction. The laser-induced damage threshold (LIDT) of samples was measured by a damage test system. Damage morphology was studied under a Nomarski differential interference contrast microscope and further checked under an atomic force microscope. Multilayers deposited at different temperatures were compared. The results show that the films deposited by ALD had better uniformity and transmission; in this paper, the uniformity is better than 99% over 100 mm {Phi} samples, and the transmission is more than 99.8% at 1064 nm. Deposition temperature affects the deposition rate and the thin film microstructure and further influences the LIDT of the thin films. As to the TiO{sub 2}/Al{sub 2}O{sub 3} films, the LIDTs were 6.73{+-}0.47 J/cm{sup 2} and 6.5{+-}0.46 J/cm{sup 2} at 110 deg. C on fused silica and BK7 substrates, respectively. The LIDTs at 110 deg. C are notably better than 280 deg. C.

  13. MOLECULARPHYSICS, 1984, VOL. 52, No. 3, 541-566 An investigation of the laser optogalvanic effect for atoms

    E-Print Network [OSTI]

    Cohen, Ronald C.

    . flames [1], positive column DC discharges [2-4], hollow cathode DC discharges [4] and radiofrequency discharges [5], that lasers operating throughout the visible and infrared have been employed as radiation

  14. Simultaneous electromagnetically induced transparency for two circularly polarized lasers coupled to the same linearly polarized laser in a four-level atomic system in the W scheme

    SciTech Connect (OSTI)

    Bahrim, Cristian; Nelson, Chris [Department of Physics, Lamar University, P.O. Box 10046, Beaumont, Texas 77710 (United States)

    2011-03-15T23:59:59.000Z

    Electromagnetic induced transparency (EIT) can be produced in a four-level atomic system in the W scheme using a linearly polarized optical field for simultaneously slowing down two {sigma}{sup +} and {sigma}{sup -} circularly polarized optical fields. This four-level atomic system can be set up with a |{sup 1}S{sub 0}> ground state and three Zeeman levels of the |{sup 1}P{sub 1}> excited state of any alkali-metal atom placed in a weak magnetic field. We apply our W scheme to ultracold magnesium atoms for neglecting the collisional dephasing. Atomic coherences are reported after solving a density matrix master equation including radiative relaxations from Zeeman states of the |{sup 1}P{sub 1}> multiplet to the |{sup 1}S{sub 0}> ground state. The EIT feature is analyzed using the transit time between the normal dispersive region and the EIT region. The evolution of the EIT feature with the variation of the coupling field is discussed using an intuitive dressed-state representation. We analyze the sensitivity of an EIT feature to pressure broadening of the excited Zeeman states.

  15. Quantum control of qubits and atomic motion using ultrafast laser J. Mizrahi B. Neyenhuis K. G. Johnson

    E-Print Network [OSTI]

    Monroe, Christopher

    as tick marks. In the context of coherent control, this feature can be used to directly bridge large to control diverse quantum systems, including multilevel atoms [5], molecules [6], semiconductor spin states

  16. Apparatus and method to control atmospheric water vapor composition and concentration during dynamic cooling of biological tissues in conjunction with laser irradiations

    DOE Patents [OSTI]

    Nelson, J. Stuart (Laguna Niguel, CA); Anvari, Bahman (Houston, TX); Tanenbaum, B. Samuel (Irvine, CA); Milner, Thomas E. (Austin, TX)

    1999-01-01T23:59:59.000Z

    Cryogen spray cooling of skin surface with millisecond cryogen spurts is an effective method for establishing a controlled temperature distribution in tissue and protecting the epidermis from nonspecific thermal injury during laser mediated dermatological procedures. Control of humidity level, spraying distance and cryogen boiling point is material to the resulting surface temperature. Decreasing the ambient humidity level results in less ice formation on the skin surface without altering the surface temperature during the cryogen spurt. For a particular delivery nozzle, increasing the spraying distance to 85 millimeters lowers the surface temperature. The methodology comprises establishing a controlled humidity level in the theater of operation of the irradiation site of the biological tissues before and/or during the cryogenic spray cooling of the biological tissue. At cold temperatures calibration was achieved by mounting a thermistor on a thermoelectric cooler. The thermal electric cooler was cooled from from 20.degree. C. to about -20.degree. C. while measuring its infrared emission.

  17. Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas M. V. Romalis

    E-Print Network [OSTI]

    Romalis, Mike

    Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas M. V. Romalis; published 7 December 2010) Optical pumping of an optically thick atomic vapor typically requires a quenching the atoms. We show that optical pumping of a trace contamination of Rb present in K metal results in a 4

  18. Atomic magnetometer for human magnetoencephalograpy.

    SciTech Connect (OSTI)

    Schwindt, Peter; Johnson, Cort N.

    2010-12-01T23:59:59.000Z

    We have developed a high sensitivity (<5 fTesla/{radical}Hz), fiber-optically coupled magnetometer to detect magnetic fields produced by the human brain. This is the first demonstration of a noncryogenic sensor that could replace cryogenic superconducting quantum interference device (SQUID) magnetometers in magnetoencephalography (MEG) and is an important advance in realizing cost-effective MEG. Within the sensor, a rubidium vapor is optically pumped with 795 laser light while field-induced optical rotations are measured with 780 nm laser light. Both beams share a single optical axis to maximize simplicity and compactness. In collaboration with neuroscientists at The Mind Research Network in Albuquerque, NM, the evoked responses resulting from median nerve and auditory stimulation were recorded with the atomic magnetometer and a commercial SQUID-based MEG system with signals comparing favorably. Multi-sensor operation has been demonstrated with two AMs placed on opposite sides of the head. Straightforward miniaturization would enable high-density sensor arrays for whole-head magnetoencephalography.

  19. Laser Processing of Metals and Polymers

    SciTech Connect (OSTI)

    Senthilraja Singaravelu

    2012-05-31T23:59:59.000Z

    A laser offers a unique set of opportunities for precise delivery of high quality coherent energy. This energy can be tailored to alter the properties of material allowing a very flexible adjustment of the interaction that can lead to melting, vaporization, or just surface modification. Nowadays laser systems can be found in nearly all branches of research and industry for numerous applications. Sufficient evidence exists in the literature to suggest that further advancements in the field of laser material processing will rely significantly on the development of new process schemes. As a result they can be applied in various applications starting from fundamental research on systems, materials and processes performed on a scientific and technical basis for the industrial needs. The interaction of intense laser radiation with solid surfaces has extensively been studied for many years, in part, for development of possible applications. In this thesis, I present several applications of laser processing of metals and polymers including polishing niobium surface, producing a superconducting phase niobium nitride and depositing thin films of niobium nitride and organic material (cyclic olefin copolymer). The treated materials were examined by scanning electron microscopy (SEM), electron probe microanalysis (EPMA), atomic force microscopy (AFM), high resolution optical microscopy, surface profilometry, Fourier transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD). Power spectral density (PSD) spectra computed from AFM data gives further insight into the effect of laser melting on the topography of the treated niobium.

  20. Isotope Enrichment Detection by Laser Ablation - Laser Absorption Spectrometry: Automated Environmental Sampling and Laser-Based Analysis for HEU Detection

    SciTech Connect (OSTI)

    Anheier, Norman C.; Bushaw, Bruce A.

    2010-01-01T23:59:59.000Z

    The global expansion of nuclear power, and consequently the uranium enrichment industry, requires the development of new safeguards technology to mitigate proliferation risks. Current enrichment monitoring instruments exist that provide only yes/no detection of highly enriched uranium (HEU) production. More accurate accountancy measurements are typically restricted to gamma-ray and weight measurements taken in cylinder storage yards. Analysis of environmental and cylinder content samples have much higher effectiveness, but this approach requires onsite sampling, shipping, and time-consuming laboratory analysis and reporting. Given that large modern gaseous centrifuge enrichment plants (GCEPs) can quickly produce a significant quantity (SQ ) of HEU, these limitations in verification suggest the need for more timely detection of potential facility misuse. The Pacific Northwest National Laboratory (PNNL) is developing an unattended safeguards instrument concept, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely analysis of enrichment levels within low enriched uranium facilities. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy to characterize the uranium isotopic ratio through subtle differences in atomic absorption wavelengths. Environmental sampling (ES) media from an integrated aerosol collector is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes material from a 10 to 20-µm diameter spot of the surface of the sampling media. The plume of ejected material begins as high-temperature plasma that yields ions and atoms, as well as molecules and molecular ions. We concentrate on the plume of atomic vapor that remains after the plasma has expanded and then cooled by the surrounding cover gas. Tunable diode lasers are directed through this plume and each isotope is detected by monitoring absorbance signals on a shot-to-shot basis. The media is translated by a micron resolution scanning system, allowing the isotope analysis to cover the entire sample surface. We also report, to the best of our knowledge, the first demonstration of laser-based isotopic measurements on individual micron-sized particles that are minor target components in a much larger heterogeneous mix of ‘background’ particles. This composition is consistent with swipe and environmental aerosol samples typically collected for safeguards ES purposes. Single-shot detection sensitivity approaching the femtogram range and relative isotope abundance uncertainty better than 10% has been demonstrated using gadolinium isotopes as surrogate materials.

  1. Vapor spill monitoring method

    DOE Patents [OSTI]

    Bianchini, Gregory M. (Livermore, CA); McRae, Thomas G. (Livermore, CA)

    1985-01-01T23:59:59.000Z

    Method for continuous sampling of liquified natural gas effluent from a spill pipe, vaporizing the cold liquified natural gas, and feeding the vaporized gas into an infrared detector to measure the gas composition. The apparatus utilizes a probe having an inner channel for receiving samples of liquified natural gas and a surrounding water jacket through which warm water is flowed to flash vaporize the liquified natural gas.

  2. Use of a diode laser to measure the polarization of an optically pumped ensemble of He(2{sup 3}{ital S}) atoms

    SciTech Connect (OSTI)

    Wallace, C.D.; Bixler, D.L.; Huang, D.; Wagman, A.H.; Dunning, F.B.; Walters, G.K. [Department of Physics and the Rice Quantum Institute, Rice University, Houston, Texas 77005-1892 (United States)] [Department of Physics and the Rice Quantum Institute, Rice University, Houston, Texas 77005-1892 (United States)

    1996-04-01T23:59:59.000Z

    A simple technique is described for determining the polarization of He(2{sup 3}{ital S}) atoms contained in an active discharge or afterglow. The polarization (and alignment) is obtained by measuring the attenuation of a circularly polarized probe beam provided by a 1.083 {mu}m laser diode whose output frequency is scanned to allow separate measurements on the 2{sup 3}{ital S}{sub 1}{r_arrow}2{sup 3}{ital P}{sub 0}, 2{sup 3}{ital S}{sub 1}{r_arrow}2{sup 3}{ital P}{sub 1}, and 2{sup 3}{ital S}{sub 1}{r_arrow}2{sup 3}{ital P}{sub 2} transitions. {copyright} {ital 1996 American Institute of Physics.}

  3. Multiphoton ionization and high-order harmonic generation of He, Ne, and Ar atoms in intense pulsed laser fields: Self-interaction-free time-dependent density-functional theoretical approach

    E-Print Network [OSTI]

    Chu, Shih-I; Tong, Xiao-Min

    2001-06-12T23:59:59.000Z

    We present a detailed study of the multiphoton ionization and high-order harmonic generation (HHG) processes of rare-gas atoms (He, Ne, and Ar) in intense pulsed laser fields by means of a self-interaction-free time-dependent density...

  4. JOURNAL DE PHYSIQUE ColZoque C9, suppZe'ment au nO1l, Tome 41, novembre 1980, page C9-449 A POTENTIAL ATOMIC IODINE LASER PUMPED BY ELECTRICALLY GENERATED 'A OXYGEN

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -449 A POTENTIAL ATOMIC IODINE LASER PUMPED BY ELECTRICALLY GENERATED 'A OXYGEN G. Fournier, J. Bonnet and D ation. This paper shows that an electron generator of 1~ oxygen [21 . A condition beam controlled discharge could be an for lasing is a concentration ratio ['A] / efficient oxygen generator to lase with C3z

  5. Continuous-wave laser oscillation on the 1315 nm transition of atomic iodine pumped by O2,,a1

    E-Print Network [OSTI]

    Carroll, David L.

    oxygen generator. There are many system issues having to do with weight, safety, and the ability.1063/1.1883317 The classic chemical oxygen-iodine laser COIL system1 operates on the I 2 P1/2 I 2 P3/2 electronic transi transfer between the metastable excited singlet oxygen molecule, O2 a1 de- noted as O2 1 hereafter

  6. Studies of silicon cluster--metal atom compound formation in a supersonic molecular beam

    SciTech Connect (OSTI)

    Beck, S.M.

    1987-10-01T23:59:59.000Z

    The first observation of a reaction between a metal atom and silicon in a supersonic jet to form metal atom silicon clusters is reported. Using the technique of laser vaporization supersonic expansion with metal carbonyl seeded carrier gas, clusters of the form MSi/sub n/ have been detected by ArF and KrF laser photoionization time-of-flight mass spectrometry. Three transition metals have been investigated, Cr, Mo, and W. The dominant product cluster peaks observed in the mass spectra obtained for all three metals corresponds to identical but remarkable cluster stoichiometries. The dominant peaks have formulas given by MSi/sub n/ where n = 15 and n = 16. The metal--semiconductor clusters are relatively more stable towards photofragmentation than the bare silicon cluster of the same size. The observation of these new species may be relevant to reactions which occur at the interface between a silicon wafer and deposited metals.

  7. Two-mode single-atom laser as a source of entangled light RID A-5077-2009 

    E-Print Network [OSTI]

    Kiffner, M.; Zubairy, M. Suhail; Evers, J.; Keitel, C. H.

    2007-01-01T23:59:59.000Z

    with the atom on the #5;b#6;? #5;d#6; transi- tion. In the rotating-wave approximation, the interaction of the atom with the cavity modes is described by the Hamil- tonian HC = #2;g1a1#5;a#6;#7;c#5; + #2;g2a2#5;b#6;#7;d#5; + H.c. #1;1#2; Here aj #1;aj?#2... mode from the #5;b#6;? #5;d#6; transition, #3;1 = #1;1 ? #4;ac, #3;2 = #1;2 ? #4;bd. #1;2#2; The resonance frequencies on the #5;a#6;? #5;c#6; and #5;b#6;? #5;d#6; tran- sitions have been labeled by #4;ac and #4;bd, respectively. In addition...

  8. Melt and vapor characteristics in an electron beam evaporator

    SciTech Connect (OSTI)

    Blumenfeld, L.; Fleche, J.L.; Gonella, C. [DCC/DPE/SPEA Centre d`Etudes de Saclay, Gif-sur-Yvette (France)

    1994-12-31T23:59:59.000Z

    We compare the free surface temperatures T{sub s}, calculated by two methods, in cerium or copper evaporation experiments. The first method considers properties of the melt: by an empirical law we take into account turbulent thermal convection, instabilities and craterization of the free surface. The second method considers the vapor flow expansion and connects T{sub s} to the measured terminal parallel temperature and the terminal mean parallel velocity of the vapor jet, by Direct Simulation Monte Carlo calculations including an atom-atom inelastic collision algorithm. The agreement between the two approaches is better for cerium than for copper in the high craterization case. The analysis, from the point of view of the properties of the melt, of the terminal parameters of the vapor jet for the high beam powers shows that T{sub s} and the Knudsen number at the vapor source reach a threshold when the beam power increases.

  9. Variable emissivity laser thermal control system

    DOE Patents [OSTI]

    Milner, J.R.

    1994-10-25T23:59:59.000Z

    A laser thermal control system for a metal vapor laser maintains the wall temperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser. 8 figs.

  10. Laser cooling with ultrafast pulse trains

    E-Print Network [OSTI]

    David Kielpinski

    2003-06-14T23:59:59.000Z

    We propose a new laser cooling method for atomic species whose level structure makes traditional laser cooling difficult. For instance, laser cooling of hydrogen requires vacuum-ultraviolet laser light, while multielectron atoms need laser light at many widely separated frequencies. These restrictions can be eased by laser cooling on two-photon transitions with ultrafast pulse trains. Laser cooling of hydrogen, antihydrogen, and carbon appears feasible, and extension of the technique to molecules may be possible.

  11. Temperature dependent vapor pressures of chlorinated catechols, syringols, and syringaldehydes

    SciTech Connect (OSTI)

    Lei, Y.D.; Shiu, W.Y.; Boocock, D.G.B. [Univ. of Toronto, Ontario (Canada). Dept. of Chemical Engineering and Applied Chemistry] [Univ. of Toronto, Ontario (Canada). Dept. of Chemical Engineering and Applied Chemistry; Wania, F. [WECC Wania Environmental Chemists Corp., Toronto, Ontario (Canada)] [WECC Wania Environmental Chemists Corp., Toronto, Ontario (Canada)

    1999-03-01T23:59:59.000Z

    The vapor pressures of nine chlorinated catechols, syringols, and syringaldehydes were determined as a function of temperature with a gas chromatographic retention time technique. The vapor pressures at 298.15 K were in the range of 0.02--1 Pa, and the enthalpies of vaporization, between 68 and 82 kJ/mol. The validity of the technique was established by a calibration involving four chlorinated phenols with well-known vapor pressures. Using these data and previously reported solubility data, Henry`s law constants for these substances and some chlorinated guaiacols and veratrols were estimated. The vapor pressure of these substances tends to decrease with increasing polarity and an increasing number of chlorine atoms. Henry`s law constants decrease sharply with increasing polarity, suggesting that methylation can result in a significant increase in a chemical`s potential for volatilization from water.

  12. Diagnostic probes for particle and molecule distributions in laser-generated plumes

    SciTech Connect (OSTI)

    Kimbrell, S.M.

    1990-10-17T23:59:59.000Z

    Laser microprobe analysis (LMA) offers good spatial and depth resolution for solid sampling of virtually any material. Coupled with numerous optical spectroscopic and mass spectrometric detection methods, LMA is a powerful analytical tool. Yet, fundamental understanding of the interaction between the laser and the sample surface leading to the formation of the high temperature plasma (plume) is far from complete. To better understand the process of plume formation, an imaging method based on acousto-optic laser beam deflection has been coupled with light scattering methods and absorption methods to record temporal and spatial maps of the particle and molecule distributions in the plume with good resolution. Because particles can make up a major fraction of the vaporized material under certain operating conditions, they can reflect a large loss of atomic signal for elemental analysis, even when using auxiliary excitation to further vaporized the particles. Characterization of the particle size distributions in plumes should provide insight into the vaporization process and information necessary for studies of efficient particle transfer. Light scattering methods for particle size analysis based on the Mie Theory are used to determine the size of particles in single laser-generated plumes. The methods used, polarization ratio method and dissymmetry ratio method, provide good estimates of particle size with good spatial and temporal resolution for this highly transient system. Large particles, on the order of 0.02-0.2{mu}m in radius, were observed arising directly from the sample surface and from condensation.

  13. Use of a diode laser to measure the spin polarization of an optically-pumped ensemble of He(2{sup 3}S) atoms

    SciTech Connect (OSTI)

    Bixler, D.L.; Wallace, C.D.; Huang, D.; Wagman, A.H.; Dunning, F.B.; Walters, G.K.

    1996-05-01T23:59:59.000Z

    A polarized He{sup +} ion source based on spin conservation in Penning ionization reactions involving polarized He(2{sup 3}S) atoms contained in an optically-pumped, rf-excited helium discharge is being developed for surface studies. To optimize source performance, the He(2{sup 3}S) polarization must be determined. The authors have devised a technique for doing this that involves measuring the attenuation of a circularly-polarized probe beam provided by a 1.083 {mu}m DBR diode laser whose output frequency is scanned by varying the drive current to allow separate measurements on the 2{sup 3}S{sub 1}-2{sup 3}P{sub 0}, 2{sup 3}P{sub 1} and 2{sup 3}P{sub 2} transitions. As will be discussed, several independent expressions for the polarization (and alignment) can be derived from the experimental data thus providing valuable internal consistency checks. The technique is simple to implement and reliable in operation.

  14. Vapor generation methods for explosives detection research. ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Vapor generation methods for explosives detection research. Vapor generation methods for explosives detection research. Abstract: The generation of calibrated vapor samples of...

  15. Electrolyte vapor condenser

    DOE Patents [OSTI]

    Sederquist, R.A.; Szydlowski, D.F.; Sawyer, R.D.

    1983-02-08T23:59:59.000Z

    A system is disclosed for removing electrolyte from a fuel cell gas stream. The gas stream containing electrolyte vapor is supercooled utilizing conventional heat exchangers and the thus supercooled gas stream is passed over high surface area passive condensers. The condensed electrolyte is then drained from the condenser and the remainder of the gas stream passed on. The system is particularly useful for electrolytes such as phosphoric acid and molten carbonate, but can be used for other electrolyte cells and simple vapor separation as well. 3 figs.

  16. Dimensional scaling treatment with relativistic corrections for stable multiply charged atomic ions in high-frequency super-intense laser fields

    E-Print Network [OSTI]

    Kais, Sabre

    in high-frequency super-intense laser fields Ross D. Hoehn, Jiaxiang Wang, and Sabre Kais Citation-intense laser fields Ross D. Hoehn,1 Jiaxiang Wang,2 and Sabre Kais1,a) 1 Departments of Chemistry and Physics

  17. Detection of transient fluorine atoms

    SciTech Connect (OSTI)

    Loge, G.W.; Nereson, N.; Fry, H.A.

    1986-01-01T23:59:59.000Z

    A KrF eximer laser with a fluence of 50 mJ/cm/sup 2/ was used to photolyze either uranium hexafluoride or molecular fluorine, yielding a transient number density of fluorine atoms. The rise and decay of the atomic fluorine density was observed by transient absorption of a 25-..mu..m Pb-salt diode laser. To prevent the diode laser wavelength from drifting out of resonance with the atomic fluorine line, part of the beam was split off and sent through a microwave discharge fluorine atom cell. This allowed a wavelength modulation-feedback technique to be used to lock the diode laser wavelength onto the atomic line. The remaining diode laser beam was made collinear with the eximer laser beam using a LiF window with a 45/sup 0/ angle of incidence to reflect the infrared beam while transmitting most of the uv beam. Using this setup along with a transient digitizer to average between 100 and 200 transient absorption profiles, fluorine atom number densities on the order of 10/sup 14/ cm/sup -3/ in a 1.7 m pathlength were detected. The signals observed were about a factor of two less than expected from known photolysis and atomic fluorine absorption cross-sections. 2 refs., 4 figs.

  18. Organic vapor jet printing system

    DOE Patents [OSTI]

    Forrest, Stephen R

    2012-10-23T23:59:59.000Z

    An organic vapor jet printing system includes a pump for increasing the pressure of an organic flux.

  19. Stratified vapor generator

    DOE Patents [OSTI]

    Bharathan, Desikan (Lakewood, CO); Hassani, Vahab (Golden, CO)

    2008-05-20T23:59:59.000Z

    A stratified vapor generator (110) comprises a first heating section (H.sub.1) and a second heating section (H.sub.2). The first and second heating sections (H.sub.1, H.sub.2) are arranged so that the inlet of the second heating section (H.sub.2) is operatively associated with the outlet of the first heating section (H.sub.1). A moisture separator (126) having a vapor outlet (164) and a liquid outlet (144) is operatively associated with the outlet (124) of the second heating section (H.sub.2). A cooling section (C.sub.1) is operatively associated with the liquid outlet (144) of the moisture separator (126) and includes an outlet that is operatively associated with the inlet of the second heating section (H.sub.2).

  20. VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

    SciTech Connect (OSTI)

    Eric M. Suuberg; Vahur Oja

    1997-07-01T23:59:59.000Z

    This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

  1. Method for enhanced atomization of liquids

    DOE Patents [OSTI]

    Thompson, Richard E. (27121 Puerta del Oro, Mission Viejo, CA 92691); White, Jerome R. (44755 Wyandotte, Hemet, CA 92544)

    1993-01-01T23:59:59.000Z

    In a process for atomizing a slurry or liquid process stream in which a slurry or liquid is passed through a nozzle to provide a primary atomized process stream, an improvement which comprises subjecting the liquid or slurry process stream to microwave energy as the liquid or slurry process stream exits the nozzle, wherein sufficient microwave heating is provided to flash vaporize the primary atomized process stream.

  2. E-Print Network 3.0 - atomic emission detection Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    laser pulse exciting both atoms... degree in Heralded entanglement of arbitrary degree in remote atoms by ... Source: Hensinger, Winfried - Department of Physics and Astronomy,...

  3. To estimate vapor pressure easily

    SciTech Connect (OSTI)

    Yaws, C.L.; Yang, H.C. (Lamar Univ., Beaumont, TX (USA))

    1989-10-01T23:59:59.000Z

    Vapor pressures as functions of temperature for approximately 700 major organic chemical compounds are given. The tabulation also gives the temperature range for which the data are applicable. Minimum and maximum temperatures are denoted by TMIN and TMAX. The Antoine equation that correlates vapor pressure as a function of temperature is described. A representative comparison of calculated and actual data values for vapor pressure is shown for ethyl alcohol. The coefficient tabulation is based on both literature (experimental data) and estimated values.

  4. Infrared emission from the substrate of GaAs-based semiconductor lasers Mathias Ziegler,1,a

    E-Print Network [OSTI]

    Peinke, Joachim

    by metal- organic vapor phase epitaxy on a n-type GaAs substrate. The red-emitting laser employs an InGaP

  5. Water Vapor Experiment Concludes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1DOE AwardsDNitrateEnergyNews3 Water Vapor

  6. ARM Water Vapor IOP

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP Update Information on new,Scanning Radar323ARM Water Vapor IOP

  7. Vapor Transport in Dry Soils

    SciTech Connect (OSTI)

    Gee, Glendon W.; Ward, Anderson L.

    2001-11-16T23:59:59.000Z

    Water-vapor movement in soils is a complex process, controlled by both diffusion and advection and influenced by pressure and thermal gradients acting across tortuous flow paths. Wide-ranging interest in water-vapor transport includes both theoretical and practical aspects. Just how pressure and thermal gradients enhance water-vapor flow is still not completely understood and subject to ongoing research. Practical aspects include dryland farming (surface mulching), water harvesting (aerial wells), fertilizer placement, and migration of contaminants at waste-sites. The following article describes the processes and practical applications of water-vapor transport, with emphasis on unsaturated (dry) soil systems.

  8. Vaporization of zinc from scrap

    SciTech Connect (OSTI)

    Ozturk, B.; Fruehan, R.J. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    1996-12-31T23:59:59.000Z

    The rate of zinc vaporization from galvanized scrap was measured using a thermogravimetric apparatus along with chemical analysis. It is found that the rate of zinc vaporization is very fast in nitrogen and carbon monoxide atmospheres at temperatures higher than 950 C. At lower temperature rate decreases with decreasing temperature and is controlled by the gas phase mass transport. The simultaneous oxidation and vaporization of zinc occurs when the samples were heated in carbon dioxide and air. The current experimental results indicate that almost all of the zinc from scrap vaporizes during the heating process in a very short period of time after the temperature reaches above 850 C.

  9. Enhancing extreme ultraviolet photons emission in laser produced plasmas for advanced lithography

    E-Print Network [OSTI]

    Harilal, S. S.

    subjected to laser beam energy with different intensities and laser wavelength to dual-beam lasers, i of vapor expansion rate, which can be produced as a result of droplet heating by pre-pulse laser energy, and the remaining part of the laser heats the plasma instead of inter- acting with the target. For obtaining

  10. Laser removal of sludge from steam generators

    DOE Patents [OSTI]

    Nachbar, Henry D. (Ballston Lake, NY)

    1990-01-01T23:59:59.000Z

    A method of removing unwanted chemical deposits known as sludge from the metal surfaces of steam generators with laser energy is provided. Laser energy of a certain power density, of a critical wavelength and frequency, is intermittently focused on the sludge deposits to vaporize them so that the surfaces are cleaned without affecting the metal surface (sludge substrate). Fiberoptic tubes are utilized for laser beam transmission and beam direction. Fiberoptics are also utilized to monitor laser operation and sludge removal.

  11. Vapor spill pipe monitor

    DOE Patents [OSTI]

    Bianchini, G.M.; McRae, T.G.

    1983-06-23T23:59:59.000Z

    The invention is a method and apparatus for continually monitoring the composition of liquefied natural gas flowing from a spill pipe during a spill test by continually removing a sample of the LNG by means of a probe, gasifying the LNG in the probe, and sending the vaporized LNG to a remote ir gas detector for analysis. The probe comprises three spaced concentric tubes surrounded by a water jacket which communicates with a flow channel defined between the inner and middle, and middle and outer tubes. The inner tube is connected to a pump for providing suction, and the probe is positioned in the LNG flow below the spill pipe with the tip oriented partly downward so that LNG is continuously drawn into the inner tube through a small orifice. The probe is made of a high thermal conductivity metal. Hot water is flowed through the water jacket and through the flow channel between the three tubes to provide the necessary heat transfer to flash vaporize the LNG passing through the inner channel of the probe. The gasified LNG is transported through a connected hose or tubing extending from the probe to a remote ir sensor which measures the gas composition.

  12. Effects of Laser Energy and Wavelength on the Analysis of LiFePO4...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Laser Energy and Wavelength on the Analysis of LiFePO4 Using Laser Assisted Atom Probe Tomography. Effects of Laser Energy and Wavelength on the Analysis of LiFePO4 Using Laser...

  13. Laser Cooling of Matter INTRODUCTION

    E-Print Network [OSTI]

    Kaiser, Robin

    - velopment of techniques that have allowed the ion motion to be cooled into the ground state of the confiningLaser Cooling of Matter INTRODUCTION Laser cooling of neutral atoms in the past decades has been a breakthrough in the understanding of their dy- namics and led to the seminal proposals of laser cooling

  14. Nuclear heated and powered metal excimer laser

    SciTech Connect (OSTI)

    Womack, D.R.

    1982-02-11T23:59:59.000Z

    A laser uses heat and thermionic electrical output from a nuclear reactor in which heat generated by the reactor is utilized to vaporize metal lasants. Voltage output from a thermionic converter is used to create an electric discharge in the metal vapors. In one embodiment the laser vapors are excited by a discharge only. The second embodiment utilizes fission coatings on the inside of heat pipes, in which fission fragment excitation and ionization is employed in addition to a discharge. Both embodiments provide efficient laser systems that are capable of many years of operation without servicing. Metal excimers are the most efficient electronic transition lasers known with output in the visible wavelengths. Use of metal excimers, in addition to their efficiency and wavelengths, allows utilization of reactor waste heat which plagues many nuclear pumped laser concepts.

  15. High average power magnetic modulator for copper lasers

    SciTech Connect (OSTI)

    Cook, E.G.; Ball, D.G.; Birx, D.L.; Branum, J.D.; Peluso, S.E.; Langford, M.D.; Speer, R.D.; Sullivan, J.R.; Woods, P.G.

    1991-06-14T23:59:59.000Z

    Magnetic compression circuits show the promise of long life for operation at high average powers and high repetition rates. When the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory needed new modulators to drive their higher power copper lasers in the Laser Demonstration Facility (LDF), existing technology using thyratron switched capacitor inversion circuits did not meet the goal for long lifetimes at the required power levels. We have demonstrated that magnetic compression circuits can achieve this goal. Improving thyratron lifetime is achieved by increasing the thyratron conduction time, thereby reducing the effect of cathode depletion. This paper describes a three stage magnetic modulator designed to provide a 60 kV pulse to a copper laser at a 4. 5 kHz repetition rate. This modulator operates at 34 kW input power and has exhibited MTBF of {approx}1000 hours when using thyratrons and even longer MTBFs with a series of stack of SCRs for the main switch. Within this paper, the electrical and mechanical designs for the magnetic compression circuits are discussed as are the important performance parameters of lifetime and jitter. Ancillary circuits such as the charge circuit and reset circuit are shown. 8 refs., 5 figs., 1 tab.

  16. Laser Programs, the first 25 years, 1972-1997

    SciTech Connect (OSTI)

    Campbell, E.M.

    1998-03-04T23:59:59.000Z

    Welcome to Laser Programs. I am pleased that you can share in the excitement of 25 years of history since we began as a small program of 125 people to our current status as a world premier laser and applied science research team of over 1700 members. It is fitting that this program, which was founded on the dream of developing inertial confinement fusion technology, should celebrate this anniversary the same year that the ground is broken for the National Ignition Facility (NIF). Also at the same time, we are feeling the excitement of moving forward the Atomic Vapor Laser Isotope Separation (AVLIS) technology toward private sector use and developing many alternate scientific applications and technologies derived from our core programs. It is through the hard work of many dedicated scientists, engineers, technicians, and administrative team members that we have been able to accomplish the remarkable internationally recognized achievements highlighted here. I hope this brochure will help you enjoy the opportunity to share in the celebration and pride of our scientific accomplishments; state-of-the-art facilities; and diligent, dedicated people that together make our Laser Programs and Lawrence Livermore National Laboratory the best in the world.

  17. Vapor Retarder Classification - Building America Top Innovation...

    Energy Savers [EERE]

    the Top Innovation. See an example of vapor retarder best practices in action. Find other case studies of Building America projects across the country that utilizes vapor retarder...

  18. Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid-Vapor Pressure Isotope Effects

    E-Print Network [OSTI]

    Chickos, James S.

    Enthalpies of Vaporization and Vapor Pressures of Some Deuterated Hydrocarbons. Liquid hydrocarbons and their perdeuterated analogues have been determined by correlation-gas chromatography of cyclohexane-d12 and benzene-d6. Other hydrocarbons studied include the perdeuterated forms of hexane, toluene

  19. Passive vapor extraction feasibility study

    SciTech Connect (OSTI)

    Rohay, V.J.

    1994-06-30T23:59:59.000Z

    Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft{sup 3}/min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft{sup 3}/min air flow rates, passive vapor extraction is more cost effective below 100 ppm.

  20. atom transfer reactions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2d-PIC simulation of atomic clusters in intense laser fields F. Greschik and H.-J. Kull, Plasma Physics and Fusion Websites Summary: properties of atomic clusters (Ditmire et al....

  1. Symposium on atomic spectroscopy (SAS-83): abstracts and program

    SciTech Connect (OSTI)

    Not Available

    1983-09-01T23:59:59.000Z

    Abstracts of papers given at the symposium are presented. Session topics include: Rydbergs, optical radiators, and planetary atoms; highly ionized atoms; ultraviolet radiation; theory, ion traps, and laser cooling; beam foil; and astronomy. (GHT)

  2. Optical isotope shift and hyperfine structure measurements in preparation of the ultra-sensitive detection of krypton atoms using stepwise laser excitation and field ionization 

    E-Print Network [OSTI]

    Lassen, Jens

    1996-01-01T23:59:59.000Z

    of the laser and a Gaussian distribution the numerical value of the time of flight bmadening differs slightly [I 8]. T A ?& ? f d t[E, exp( ? 2r / d) cos(to, t)] exp( ? i mt) 0 I(?& ? AA* = C*expI ? (fo ? m, )d/(2v~2)' J E:=E, cos(fo, t) Svfa~-:5. 6...

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

    E-Print Network [OSTI]

    Carroll, David L.

    peroxide and Cl2 gas. Logistic issues with this chemical sin- glet oxygen generator motivated many by a radio-frequency-excited electric discharge sustained in a dry air-He­NO gas mixture. Active oxygen American Institute of Physics. DOI: 10.1063/1.2957678 The classical chemical oxygen iodine laser COIL re

  4. Kinetics of wet sodium vapor complex plasma

    SciTech Connect (OSTI)

    Mishra, S. K., E-mail: nishfeb@rediffmail.com [Institute for Plasma Research (IPR), Gandhinagar 382428 (India); Sodha, M. S. [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)] [Centre of Energy Studies, Indian Institute of Technology Delhi (IITD), New Delhi 110016 (India)

    2014-04-15T23:59:59.000Z

    In this paper, we have investigated the kinetics of wet (partially condensed) Sodium vapor, which comprises of electrons, ions, neutral atoms, and Sodium droplets (i) in thermal equilibrium and (ii) when irradiated by light. The formulation includes the balance of charge over the droplets, number balance of the plasma constituents, and energy balance of the electrons. In order to evaluate the droplet charge, a phenomenon for de-charging of the droplets, viz., evaporation of positive Sodium ions from the surface has been considered in addition to electron emission and electron/ion accretion. The analysis has been utilized to evaluate the steady state parameters of such complex plasmas (i) in thermal equilibrium and (ii) when irradiated; the results have been graphically illustrated. As a significant outcome irradiated, Sodium droplets are seen to acquire large positive potential, with consequent enhancement in the electron density.

  5. Chemical vapor deposition of group IIIB metals

    DOE Patents [OSTI]

    Erbil, A.

    1989-11-21T23:59:59.000Z

    Coatings of Group IIIB metals and compounds thereof are formed by chemical vapor deposition, in which a heat decomposable organometallic compound of the formula given in the patent where M is a Group IIIB metal, such as lanthanum or yttrium and R is a lower alkyl or alkenyl radical containing from 2 to about 6 carbon atoms, with a heated substrate which is above the decomposition temperature of the organometallic compound. The pure metal is obtained when the compound of the formula 1 is the sole heat decomposable compound present and deposition is carried out under nonoxidizing conditions. Intermetallic compounds such as lanthanum telluride can be deposited from a lanthanum compound of formula 1 and a heat decomposable tellurium compound under nonoxidizing conditions.

  6. Production of higher quality bio-oils by in-line esterification of pyrolysis vapor

    DOE Patents [OSTI]

    Hilten, Roger Norris; Das, Keshav; Kastner, James R; Bibens, Brian P

    2014-12-02T23:59:59.000Z

    The disclosure encompasses in-line reactive condensation processes via vapor phase esterification of bio-oil to decease reactive species concentration and water content in the oily phase of a two-phase oil, thereby increasing storage stability and heating value. Esterification of the bio-oil vapor occurs via the vapor phase contact and subsequent reaction of organic acids with ethanol during condensation results in the production of water and esters. The pyrolysis oil product can have an increased ester content and an increased stability when compared to a condensed pyrolysis oil product not treated with an atomized alcohol.

  7. Fabrication of nano-structural arrays by channeling pulsed atomic beams through pulsed-laser standing-waves under off-resonant condition

    E-Print Network [OSTI]

    Zhu, Xiangdong

    Fabrication of nano-structural arrays by channeling pulsed atomic beams through pulsed 1998 We show that it is feasible to produce one- and two-dimensional nano-structure arrays by passing the reduced dimensions are of the order of nanometers (10 9 m . In particular, nano

  8. Portable vapor diffusion coefficient meter

    DOE Patents [OSTI]

    Ho, Clifford K. (Albuquerque, NM)

    2007-06-12T23:59:59.000Z

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  9. FY14 Progress Report for PL12-LaserSPec SIMS-PD08: Laser Photoionization of Sputtered Neutral atoms in PNNL SIMS and Applications in Nuclear Materials and Environmental Analyses

    SciTech Connect (OSTI)

    Willingham, David G.; Naes, Benjamin E.; Fahey, Albert J.; Thompson, Sandra E.; Cloutier, Janet M.

    2014-12-18T23:59:59.000Z

    A continuous wave (CW) Ar ion laser producing photons at 244 nm (doubled from the fundamental wavelength at 488nm) was used to ionize neutrals sputtered from representative lanthanide (neodymium oxide, Nd2O3) and actinide (uranium oxide, U3O8) containing materials in the modified Cameca ims-4f at PNNL.

  10. Vapor deposition of hardened niobium

    DOE Patents [OSTI]

    Blocher, Jr., John M. (Columbus, OH); Veigel, Neil D. (Columbus, OH); Landrigan, Richard B. (Columbus, OH)

    1983-04-19T23:59:59.000Z

    A method of coating ceramic nuclear fuel particles containing a major amount of an actinide ceramic in which the particles are placed in a fluidized bed maintained at ca. 800.degree. to ca. 900.degree. C., and niobium pentachloride vapor and carbon tetrachloride vapor are led into the bed, whereby niobium metal is deposited on the particles and carbon is deposited interstitially within the niobium. Coating apparatus used in the method is also disclosed.

  11. Method for laser machining explosives and ordnance

    DOE Patents [OSTI]

    Muenchausen, Ross E.; Rivera, Thomas; Sanchez, John A.

    2003-05-06T23:59:59.000Z

    Method for laser machining explosives and related articles. A laser beam is directed at a surface portion of a mass of high explosive to melt and/or vaporize the surface portion while directing a flow of gas at the melted and/or vaporized surface portion. The gas flow sends the melted and/or vaporized explosive away from the charge of explosive that remains. The method also involves splitting the casing of a munition having an encased explosive. The method includes rotating a munition while directing a laser beam to a surface portion of the casing of an article of ordnance. While the beam melts and/or vaporizes the surface portion, a flow of gas directed at the melted and/or vaporized surface portion sends it away from the remaining portion of ordnance. After cutting through the casing, the beam then melts and/or vaporizes portions of the encased explosive and the gas stream sends the melted/vaporized explosive away from the ordnance. The beam is continued until it splits the article, after which the encased explosive, now accessible, can be removed safely for recycle or disposal.

  12. Initiation of nuclear reactions under laser irradiation of Au nanoparticles in the aqueous solution of Uranium salt

    E-Print Network [OSTI]

    A. V. Simakin; G. A. Shafeev

    2009-11-29T23:59:59.000Z

    Laser exposure of suspension of either gold or palladium nanoparticles in aqueous solutions of UO2Cl2 of natural isotope abundance was experimentally studied. Picosecond Nd:YAG lasers at peak power from 1011 to 1013 W/cm2 at the wavelength of 1064 and 355 nm were used as well as a visible-range Cu vapor laser at peak power of 1010 W/cm2. The composition of colloidal solutions before and after laser exposure was analyzed using atomic absorption and gamma spectroscopy between 0.06 and 1 MeV range of photon energy. A real-time gamma-spectroscopy was used to characterize the kinetics of nuclear reactions during laser exposure. It was found that laser exposure initiated nuclear reactions involving both 238U and 235U nuclei via different channels in H2O and D2O. The influence of saturation of both the liquid and nanoparticles by gaseous H2 and D2 on the kinetics of nuclear transformations was found. Possible mechanisms of observed processes are discussed.

  13. atomic vapor deposited: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    deposition onto micro- and nanopowders14 and coating of nanoparticle films15 as well as aerogel coating of porous materials that exhibit ultrahigh-aspect ratios.12,13 To date,...

  14. Modeling Nonlinear Magneto-optical Effects in Atomic Vapors

    E-Print Network [OSTI]

    Rochester, Simon Michael

    2010-01-01T23:59:59.000Z

    10.1 Doppler-free transit effect . . . . . . . . . . . .10.2 Doppler-broadened transit effect . . . . . . . . . 10.3Doppler-free transit effect . . . . . . . . . . . . . . . . . . . . . .

  15. Site-Specific Laser Modification of MgO nanoclusters: Towards...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Laser Modification of MgO nanoclusters: Towards Atomic-Scale Surface Structuring. Site-Specific Laser Modification of MgO nanoclusters: Towards Atomic-Scale Surface Structuring....

  16. Electrical, optical, and material characterizations of blue InGaN light emitting diodes submitted to reverse-bias stress in water vapor condition

    SciTech Connect (OSTI)

    Chen, Hsiang, E-mail: hchen@ncnu.edu.tw; Chu, Yu-Cheng; Chen, Yun-Ti; Chen, Chian-You [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, No. 1, University Road, Puli, Nantou County 54561, Taiwan (China); Shei, Shih-Chang [Department of Electrical Engineering, National University of Tainan, No.33, Sec. 2, Shulin St., West Central Dist., Tainan City 70005, Taiwan (China)

    2014-09-07T23:59:59.000Z

    In this paper, we investigate degradation of InGaN/GaN light emitting diodes (LEDs) under reverse-bias operations in water vapor and dry air. To examine failure origins, electrical characterizations including current-voltage, breakdown current profiles, optical measurement, and multiple material analyses were performed. Our findings indicate that the diffusion of indium atoms in water vapor can expedite degradation. Investigation of reverse-bias stress can help provide insight into the effects of water vapor on LEDs.

  17. Noisy quadrature of squeezed light and laser cooling

    E-Print Network [OSTI]

    G. M. Saxena; A. Agarwal

    2008-07-01T23:59:59.000Z

    The laser cooling of atoms is a result of the combined effect of doppler shift, light shift and polarization gradient. These are basically undesirable phenomena. However, they combine gainfully in realizing laser cooling and trapping of the atoms. In this paper we discuss the laser cooling of atoms in the presence of the squeezed light with the decay of atomic dipole moment into noisy quadrature. We show that the higher decay rate of the atomic dipole moment into the noisy quadrature, which is also an undesirable effect, may contribute in realizing larger cooling force vis-a-vis normal laser light.

  18. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    1998-01-01T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition.

  19. Laser ablation based fuel ignition

    DOE Patents [OSTI]

    Early, J.W.; Lester, C.S.

    1998-06-23T23:59:59.000Z

    There is provided a method of fuel/oxidizer ignition comprising: (a) application of laser light to a material surface which is absorptive to the laser radiation; (b) heating of the material surface with the laser light to produce a high temperature ablation plume which emanates from the heated surface as an intensely hot cloud of vaporized surface material; and (c) contacting the fuel/oxidizer mixture with the hot ablation cloud at or near the surface of the material in order to heat the fuel to a temperature sufficient to initiate fuel ignition. 3 figs.

  20. Vapor deposition of thin films

    DOE Patents [OSTI]

    Smith, David C. (Los Alamos, NM); Pattillo, Stevan G. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Sattelberger, Alfred P. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

    A highly pure thin metal film having a nanocrystalline structure and a process of preparing such highly pure thin metal films of, e.g., rhodium, iridium, molybdenum, tungsten, rhenium, platinum, or palladium by plasma assisted chemical vapor deposition of, e.g., rhodium(allyl).sub.3, iridium(allyl).sub.3, molybdenum(allyl).sub.4, tungsten(allyl).sub.4, rhenium(allyl).sub.4, platinum(allyl).sub.2, or palladium(allyl).sub.2 are disclosed. Additionally, a general process of reducing the carbon content of a metallic film prepared from one or more organometallic precursor compounds by plasma assisted chemical vapor deposition is disclosed.

  1. Deep superconducting magnetic traps for neutral atoms and molecules J. G. E. Harris,a)

    E-Print Network [OSTI]

    Harris, Jack

    2003 We describe the design, construction and performance of three realizations of a high of the coils into a cryogenic vacuum environment suitable for producing cold atoms and molecules. © 2004 atomic vapors away from material walls, thereby breaking thermal contact be- tween the trapped atoms

  2. Cavity cooling of a single atom P. Maunz, T. Puppe, I. Schuster, N. Syassen, P. W. H. Pinkse & G. Rempe

    E-Print Network [OSTI]

    Rempe, Gerhard

    .............................................................. Cavity cooling of a single atom P ............................................................................................................................................................................. All conventional methods to laser-cool atoms rely on repeated cycles of optical pumping the dissipative mechanism required to remove entropy from the atom. However, alternative cooling methods have been

  3. Vacuum vapor deposition gun assembly

    DOE Patents [OSTI]

    Zeren, Joseph D. (Boulder, CO)

    1985-01-01T23:59:59.000Z

    A vapor deposition gun assembly includes a hollow body having a cylindrical outer surface and an end plate for holding an adjustable heat sink, a hot hollow cathode gun, two magnets for steering the plasma from the gun into a crucible on the heat sink, and a shutter for selectively covering and uncovering the crucible.

  4. Hydrogen Cars and Water Vapor

    E-Print Network [OSTI]

    Colorado at Boulder, University of

    misidentified as "zero-emissions vehicles." Fuel cell vehicles emit water vapor. A global fleet could have, with discernible effects on people and ecosystems. The broad environmental effects of fuel cell vehicles. This cycle is currently under way with hydrogen fuel cells. As fuel cell cars are suggested as a solution

  5. Intense Femtosecond Laser Interactions with Ions in

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ), ultra-short laser light with atoms and molecules has led to the discovery of new phenomena such as bondIntense Femtosecond Laser Interactions with Ions in Beams and Traps A thesis presented through a re-scattering process where an electron is ionized, propagated in the laser field and is driven

  6. Recirculating wedges for metal-vapor plasma tubes

    DOE Patents [OSTI]

    Hall, J.P.; Sawvel, R.M.; Draggoo, V.G.

    1994-06-28T23:59:59.000Z

    A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior. 8 figures.

  7. Stimulated emission of ultraviolet radiation by vapors of complex molecules

    SciTech Connect (OSTI)

    Barkova, L.A.; Gruzinskii, V.V.; Danilova, V.I.; Degtyarenko, K.M.; Kopylova, T.N.; Kuznetsov, A.L.

    1981-08-01T23:59:59.000Z

    Lasing was observed in vapors of new organic compounds: para-terphenyl, 2-phenylbenzoxazole, 2-(n-tolyl) benzoxazole, 2-(n-methoxyphenyl) benzoxazole, 2-(n-dimethylaminophenyl) benzoxazole, 2-biphenylbenzoxazole, 2-(..cap alpha..-naphthyl) benzoxazole, and also 1,4-di(n-phenylethynyl) benzole, and para-quaterphenyl pumped transversely by XeCl excimer laser radiation at lambda/sub p/ = 308 nm. The lasing bands without tuning covered the 330--370 nm range. The shortest-wavelength maximum (333.5 nm) was observed for 2-(n-methoxyphenyl) benzoxazole. An analysis was made of the lasing ability of the molecules.

  8. Recirculating wedges for metal-vapor plasma tubes

    DOE Patents [OSTI]

    Hall, Jerome P. (Livermore, CA); Sawvel, Robert M. (Modesto, CA); Draggoo, Vaughn G. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior.

  9. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, Barbara K. (Charleston, WV)

    1991-01-01T23:59:59.000Z

    Volatilized metal compounds retard vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  10. Safeguards Verification Measurements using Laser Ablation, Absorbance Ratio Spectrometry in Gaseous Centrifuge Enrichment Plants

    SciTech Connect (OSTI)

    Anheier, Norman C.; Cannon, Bret D.; Kulkarni, Gourihar R.; Munley, John T.; Nelson, Danny A.; Qiao, Hong (Amy) [Amy; Phillips, Jon R.

    2012-07-17T23:59:59.000Z

    Laser Ablation Absorbance Ratio Spectrometry (LAARS) is a new verification measurement technology under development at the US Department of Energy (DOE) Pacific Northwest National Laboratory (PNNL). LAARS uses three lasers to ablate and then measure the relative isotopic abundance of uranium compounds. An ablation laser is tightly focused on uranium-bearing solids, producing a small atomic uranium vapor plume. Two collinear wavelength-tuned spectrometry lasers transit through the plume and the absorbance of U-235 and U-238 isotopes are measured to determine U-235 enrichment. The measurement is independent of chemical form and degree of dilution with nuisance dust and other materials. LAARS has high relative precision and detection limits approaching the femtogram range for U-235. The sample is scanned and assayed point-by-point at rates reaching 1 million measurements/hour, enabling LAARS to detect and analyze uranium in trace samples. The spectrometer is assembled using primarily commercially available components and features a compact design and automated analysis.Two specific gaseous centrifuge enrichment plant (GCEP) applications of the spectrometer are currently under development: 1) LAARS-Environmental Sampling (ES), which collects and analyzes aerosol particles for GCEP misuse detection and 2) LAARS-Destructive Assay (DA), which enables onsite enrichment DA sample collection and analysis for protracted diversion detection. The two applications propose game-changing technological advances in GCEP safeguards verification.

  11. Optimization of process parameters for pulsed laser milling of micro-channels on AISI H13 tool steel

    E-Print Network [OSTI]

    Ozel, Tugrul

    selection Laser milling process a b s t r a c t This paper focuses on understanding the influence of laser. Whenever metals are used, the laser beam heats, melts and vaporizes the metal (metal sublimation), whileOptimization of process parameters for pulsed laser milling of micro-channels on AISI H13 tool

  12. LBNL-42730 1 Collisional Perturbation of States in Atomic Ytterbium by Helium and Neon

    E-Print Network [OSTI]

    Pines, Alexander

    LBNL-42730 1 Collisional Perturbation of States in Atomic Ytterbium by Helium and Neon D-photon radiative decays from the 3 P0 state to the ground state #12;LBNL-42730 2 are strictly forbidden by the J=0 transitions for the proposed PNC experiment in a vapor cell. #12;LBNL-42730 3 In a vapor cell experiment

  13. Comparative analysis of the high-order harmonic generation in the laser ablation plasmas prepared on the surfaces of complex and atomic targets

    SciTech Connect (OSTI)

    Ganeev, R. A. [Scientific Association Akadempribor, Academy of Sciences of Uzbekistan, Akademgorodok, Tashkent 100125 (Uzbekistan); Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581 (Japan); Milosevic, D. B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2008-07-15T23:59:59.000Z

    We analyzed high-order harmonic generation from the plasma plumes prepared on the surfaces of complex targets. The studies of In-Ag targets showed that the characteristics of the high-order harmonics from the double-target plume were the same as those from the single-target plasmas. For the chromium-tellurium plasma, the enhancements of the 29th and 27th harmonics were obtained, thus indicating the appearance of the enhancement properties from both components of the double-target plasma. These comparative studies also showed higher enhancement of a single harmonic in the case of atomic plasma (Sb) with regard to the molecular one (InSb). The additional component can only decrease the enhancement factor of the medium, due to the change of the oscillator strength and spectral distribution of the transitions involved in the resonance enhancement of the specific harmonic order. The theoretical calculations have shown the enhancement of specific harmonics for the Sb, Te, and Cr plasmas in the double-target configurations.

  14. Vapor canister heater for evaporative emissions systems

    SciTech Connect (OSTI)

    Bishop, R.P.; Berg, P.G.

    1987-01-01T23:59:59.000Z

    Automotive evaporative emissions systems use a charcoal canister to store evaporative hydrocarobn emissions. These stored vapors are later purged and burned during engine operation. Under certain conditions the engine cannot completely purge the canister of the stored fuel vapors, which results in a decreased vapor storage capacity in the canister. A self-regulating PTC (Positive Temperature Coefficient) heater has been developed to warm the purge air as it enters the canister, in order to provide thermal energy for increased release of the vapors from charcoal sites. This paper describes the construction and operation of the vapor canister heater as it relates to improved evaporative emission system performance.

  15. Means and method for vapor generation

    DOE Patents [OSTI]

    Carlson, Larry W. (Oswego, IL)

    1984-01-01T23:59:59.000Z

    A liquid, in heat transfer contact with a surface heated to a temperature well above the vaporization temperature of the liquid, will undergo a multiphase (liquid-vapor) transformation from 0% vapor to 100% vapor. During this transition, the temperature driving force or heat flux and the coefficients of heat transfer across the fluid-solid interface, and the vapor percentage influence the type of heating of the fluid--starting as "feedwater" heating where no vapors are present, progressing to "nucleate" heating where vaporization begins and some vapors are present, and concluding with "film" heating where only vapors are present. Unstable heating between nucleate and film heating can occur, accompanied by possibly large and rapid temperature shifts in the structures. This invention provides for injecting into the region of potential unstable heating and proximate the heated surface superheated vapors in sufficient quantities operable to rapidly increase the vapor percentage of the multiphase mixture by perhaps 10-30% and thereby effectively shift the multiphase mixture beyond the unstable heating region and up to the stable film heating region.

  16. Final Report: Cooling Molecules with Laser Light

    SciTech Connect (OSTI)

    Di Rosa, Michael D. [Los Alamos National Laboratory

    2012-05-08T23:59:59.000Z

    Certain diatomic molecules are disposed to laser cooling in the way successfully applied to certain atoms and that ushered in a revolution in ultracold atomic physics, an identification first made at Los Alamos and which took root during this program. Despite their manipulation into numerous achievements, atoms are nonetheless mundane denizens of the quantum world. Molecules, on the other hand, with their internal degrees of freedom and rich dynamical interplay, provide considerably more complexity. Two main goals of this program were to demonstrate the feasibility of laser-cooling molecules to the same temperatures as laser-cooled atoms and introduce a means for collecting laser-cooled molecules into dense ensembles, a foundational start of studies and applications of ultracold matter without equivalence in atomic systems.

  17. Picoseconds-Laser Modification of Thin Films

    SciTech Connect (OSTI)

    Gakovic, Biljana; Trtica, Milan [Institute of Nuclear Sciences 'VINCA' 522, 11001 Belgrade (Serbia and Montenegro); Batani, Dimitri; Desai, Tara; Redaelli, Renato [Dipartimento di Fisica 'G. Occhialini', Universita' degli Studi Milano-Bicocca, Piazza della Scienza 3, Milan 20126 (Italy)

    2006-04-07T23:59:59.000Z

    The interaction of a Nd:YAG laser, pulse duration of 40 ps, with a titanium nitride (TiN) and tungsten-titanium (W-Ti) thin films deposited at silicon was studied. The peak intensity on targets was up to 1012 W/cm2. Results have shown that the TiN surface was modified, by the laser beam, with energy density of {>=}0.18 J/cm2 ({lambda}laser= 532 nm) as well as of 30.0 J/cm2 ({lambda}laser= 1064 nm). The W-Ti was surface modified with energy density of 5.0 J/cm2 ({lambda}laser= 532 nm). The energy absorbed from the Nd:YAG laser beam is partially converted to thermal energy, which generates a series of effects such as melting, vaporization of molten materials, dissociation and ionization of the vaporized material, appearance of plasma, etc. The following morphological changes of both targets were observed: (i) The appearance of periodic microstructures, in the central zone of the irradiated area, for laser irradiation at 532 nm. Accumulation of great number of laser pulses caused film ablation and silicon modification. (ii) Hole formation on the titanium nitride/silicon target was registered at 1064 nm. The process of the Nd:YAG laser interaction with both targets was accompanied by plasma formation above the target.

  18. Laser Interactions in Nanomaterials Synthesis David B. Geohegan1,2

    E-Print Network [OSTI]

    Pennycook, Steve

    Laser Interactions in Nanomaterials Synthesis David B. Geohegan1,2 , Alex A. Puretzky1,2 , Chris. Laser interactions with materials have unique advantages to explore the rapid synthesis, processing, laser vaporization of solids into background gases provides a wide range of processing conditions

  19. Predictive Modeling for Glass-Side Laser Scribing of Thin Film Photovoltaic Cells

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    with reduced thermal effect. Film side laser scribing is governed by heating, melting and vaporizing of selective films. Glass side laser scribing is a thermal-mechanical process which involves stress inducedPredictive Modeling for Glass-Side Laser Scribing of Thin Film Photovoltaic Cells Hongliang Wang

  20. Coherent instabilities in random lasers

    SciTech Connect (OSTI)

    Andreasen, Jonathan; Sebbah, Patrick; Vanneste, Christian [Laboratoire de Physique de la Matiere Condensee, CNRS UMR 6622, Universite de Nice-Sophia Antipolis, Parc Valrose, F-06108, Nice Cedex 02 (France)

    2011-08-15T23:59:59.000Z

    A numerical study is presented of random lasers as a function of the pumping rate above the threshold for lasing. Depending on the leakiness of the system resonances, which is typically larger in random lasers compared to conventional lasers, we observe that the stationary lasing regime becomes unstable above a second threshold. Coherent instabilities are observed as self pulsation at a single frequency of the output intensity, population inversion, as well as the atomic polarization. We find these Rabi oscillations have the same frequency everywhere in the random laser despite the fact that the field intensity strongly depends on the spatial location.

  1. Method of physical vapor deposition of metal oxides on semiconductors

    DOE Patents [OSTI]

    Norton, David P. (Knoxville, TN)

    2001-01-01T23:59:59.000Z

    A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

  2. Optical method of atomic ordering estimation

    SciTech Connect (OSTI)

    Prutskij, T. [Instituto de Ciencias, BUAP, Privada 17 Norte, No 3417, col. San Miguel Huyeotlipan, Puebla, Pue. (Mexico); Attolini, G. [IMEM/CNR, Parco Area delle Scienze 37/A - 43010, Parma (Italy); Lantratov, V.; Kalyuzhnyy, N. [Ioffe Physico-Technical Institute, 26 Polytekhnicheskaya, St Petersburg 194021, Russian Federation (Russian Federation)

    2013-12-04T23:59:59.000Z

    It is well known that within metal-organic vapor-phase epitaxy (MOVPE) grown semiconductor III-V ternary alloys atomically ordered regions are spontaneously formed during the epitaxial growth. This ordering leads to bandgap reduction and to valence bands splitting, and therefore to anisotropy of the photoluminescence (PL) emission polarization. The same phenomenon occurs within quaternary semiconductor alloys. While the ordering in ternary alloys is widely studied, for quaternaries there have been only a few detailed experimental studies of it, probably because of the absence of appropriate methods of its detection. Here we propose an optical method to reveal atomic ordering within quaternary alloys by measuring the PL emission polarization.

  3. Control of flow through a vapor generator

    DOE Patents [OSTI]

    Radcliff, Thomas D.

    2005-11-08T23:59:59.000Z

    In a Rankine cycle system wherein a vapor generator receives heat from exhaust gases, provision is made to avoid overheating of the refrigerant during ORC system shut down while at the same time preventing condensation of those gases within the vapor generator when its temperature drops below a threshold temperature by diverting the flow of hot gases to ambient and to thereby draw ambient air through the vapor generator in the process. In one embodiment, a bistable ejector is adjustable between one position, in which the hot gases flow through the vapor generator, to another position wherein the gases are diverted away from the vapor generator. Another embodiment provides for a fixed valve ejector with a bias towards discharging to ambient, but with a fan on the downstream side of said vapor generator for overcoming this bias.

  4. Atom Interferometry

    ScienceCinema (OSTI)

    Mark Kasevich

    2010-01-08T23:59:59.000Z

    Atom de Broglie wave interferometry has emerged as a tool capable of addressing a diverse set of questions in gravitational and condensed matter physics, and as an enabling technology for advanced sensors in geodesy and navigation. This talk will review basic principles, then discuss recent applications and future directions. Scientific applications to be discussed include measurement of G (Newton?s constant), tests of the Equivalence Principle and post-Newtonian gravity, and study of the Kosterlitz-Thouless phase transition in layered superfluids. Technology applications include development of precision gryoscopes and gravity gradiometers. The talk will conclude with speculative remarks looking to the future: Can atom interference methods be sued to detect gravity waves? Can non-classical (entangled/squeezed state) atom sources lead to meaningful sensor performance improvements?

  5. Overview of chemical vapor infiltration

    SciTech Connect (OSTI)

    Besmann, T.M.; Stinton, D.P.; Lowden, R.A.

    1993-06-01T23:59:59.000Z

    Chemical vapor infiltration (CVI) is developing into a commercially important method for the fabrication of continuous filament ceramic composites. Current efforts are focused on the development of an improved understanding of the various processes in CVI and its modeling. New approaches to CVI are being explored, including pressure pulse infiltration and microwave heating. Material development is also proceeding with emphasis on improving the oxidation resistance of the interfacial layer between the fiber and matrix. This paper briefly reviews these subjects, indicating the current state of the science and technology.

  6. Vapor phase modifiers for oxidative coupling

    DOE Patents [OSTI]

    Warren, B.K.

    1991-12-17T23:59:59.000Z

    Volatilized metal compounds are described which are capable of retarding vapor phase alkane conversion reactions in oxidative coupling processes that convert lower alkanes to higher hydrocarbons.

  7. Laser Welding of Aluminum and Aluminum Alloys

    E-Print Network [OSTI]

    Eagar, Thomas W.

    .. ) Laser Welding of Aluminum and Aluminum Alloys Welds made with sharp bevel-groove weld aluminum and by aluminum alloy 5456 have been studied. The results indicate that initial absorption varies, many aluminum alloys contain magnesium or zinc, which are easily vaporized and thereby form a plasma

  8. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, V.J.; Johnson, S.A.

    1999-08-03T23:59:59.000Z

    A vapor sample detection method is described where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample. 13 figs.

  9. Near real time vapor detection and enhancement using aerosol adsorption

    DOE Patents [OSTI]

    Novick, Vincent J. (Downers Grove, IL); Johnson, Stanley A. (Countryside, IL)

    1999-01-01T23:59:59.000Z

    A vapor sample detection method where the vapor sample contains vapor and ambient air and surrounding natural background particles. The vapor sample detection method includes the steps of generating a supply of aerosol that have a particular effective median particle size, mixing the aerosol with the vapor sample forming aerosol and adsorbed vapor suspended in an air stream, impacting the suspended aerosol and adsorbed vapor upon a reflecting element, alternatively directing infrared light to the impacted aerosol and adsorbed vapor, detecting and analyzing the alternatively directed infrared light in essentially real time using a spectrometer and a microcomputer and identifying the vapor sample.

  10. Experimental investigation of the latent heat of vaporization in aqueous nanofluids

    SciTech Connect (OSTI)

    Lee, Soochan; Phelan, Patrick E., E-mail: phelan@asu.edu; Dai, Lenore; Prasher, Ravi; Gunawan, Andrey [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287-6106 (United States); Taylor, Robert A. [School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney 2052 (Australia)

    2014-04-14T23:59:59.000Z

    This paper reports an experimental investigation of the latent heat of vaporization (h{sub fg}) in nanofluids. Two different types of nanoparticles, graphite and silver, suspended in deionized water were exposed to a continuous laser beam (130 mW, 532?nm) to generate boiling. The latent heat of vaporization in the nanofluids was determined by the measured vapor mass generation and the heat input. To ensure that the measured h{sub fg} values are independent of heating method, the experiments were repeated with an electrically heated hot wire as a primary heat input. These experiments show considerable variation in the h{sub fg} of nanofluids. That is, graphite nanofluid exhibits an increased h{sub fg} and silver nanofluid shows a decrease in h{sub fg} compared to the value for pure water. As such, these results indicate that relatively low mass fractions of nanoparticles can apparently create large changes in h{sub fg}.

  11. Atomic Scale Characterization of Compound Semiconductors using Atom Probe Tomography: Preprint

    SciTech Connect (OSTI)

    Gorman, B. P.; Guthrey, H.; Norman, A. G.; Al-Jassim, M.; Lawrence, D.; Prosa, T.

    2011-07-01T23:59:59.000Z

    Internal interfaces are critical in determining the performance of III-V multijunction solar cells. Studying these interfaces with atomic resolution using a combination of transmission electron microscopy (TEM), atom probe tomography (APT), and density functional calculations enables a more fundamental understanding of carrier dynamics in photovoltaic (PV) device structures. To achieve full atomic scale spatial and chemical resolution, data acquisition parameters in laser pulsed APT must be carefully studied to eliminate surface diffusion. Atom probe data with minimized group V ion clustering and expected stoichiometry can be achieved by adjusting laser pulse power, pulse repetition rate, and specimen preparation parameters such that heat flow away from the evaporating surface is maximized. Applying these improved analysis conditions to III-V based PV gives an atomic scale understanding of compositional and dopant profiles across interfaces and tunnel junctions and the initial stages of alloy clustering and dopant accumulation. Details on APT experimental methods and future in-situ instrumentation developments are illustrated.

  12. Tropospheric water vapor and climate sensitivity

    SciTech Connect (OSTI)

    Schneider, E.K.; Kirtman, B.P.; Lindzen, R.S. [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)] [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States)

    1999-06-01T23:59:59.000Z

    Estimates are made of the effect of changes in tropospheric water vapor on the climate sensitivity to doubled carbon dioxide (CO{sub 2}) using a coarse resolution atmospheric general circulation model coupled to a slab mixed layer ocean. The sensitivity of the model to doubled CO{sub 2} is found as the difference between the equilibrium responses for control and doubled CO{sub 2} cases. Clouds are specified to isolate the water vapor feedback. Experiments in which the water vapor distribution is specified rather than internally calculated are used to find the contribution of water vapor in various layers and latitude belts to the sensitivity. The contribution of water vapor in layers of equal mass to the climate sensitivity varies by about a factor of 2 with height, with the largest contribution coming from layers between 450 and 750 mb, and the smallest from layers above 230 mb. The positive feedback on the global mean surface temperature response to doubled CO{sub 2} from water vapor above 750 mb is about 2.6 times as large as that from water vapor below 750 mb. The feedback on global mean surface temperature due to water vapor in the extratropical free troposphere is about 50% larger than the feedback due to the lower-latitude free troposphere water vapor. Several important sources of nonlinearity of the radiative heating rates were identified in the process of constructing the specified cloud and water vapor fields. These are (1) the interaction of clouds and solar radiation, which produces much more reflection of solar radiation for time mean clouds than for the instantaneous clouds; (2) the correlation of clouds and water vapor, which produces less downward longwave radiation at the ground for correlated clouds and water vapor than when these fields are independent; and (3) the interaction of water vapor with long wave radiation, which produces less downward longwave radiation at the ground of the average over instantaneous water vapor distributions than of the time mean water vapor distribution.

  13. ccsd-00001508,version1-1May2004 Realization of a magnetically guided atomic beam in the collisional regime

    E-Print Network [OSTI]

    Boyer, Edmond

    to periodically re- plenish with new condensates a gas sample held in an optical dipole trap. The second-Einstein condensation (BEC) [2] and pulsed "atom lasers" extracted from the condensate [3]. These advances in atom atom laser"). The first possibility [4] consists in using the "standard" condensation procedure

  14. Towards a quantum gas microscope for fermionic atoms

    E-Print Network [OSTI]

    Ramasesh, Vinay (Vinay V.)

    2012-01-01T23:59:59.000Z

    This thesis reports the achievement of a two-species apparatus for use in an upcoming experiment with fermionic ultracold atomic gases. First, we describe the construction of a laser system capable of cooling and trapping ...

  15. atomic power generation: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    a squeezed atom laser is to use Queensland, University of 420 A Silicon-Based Micro Gas Turbine Engine for Power Generation CERN Preprints Summary: This paper reports on our...

  16. LNG fire and vapor control system technologies

    SciTech Connect (OSTI)

    Konzek, G.J.; Yasutake, K.M.; Franklin, A.L.

    1982-06-01T23:59:59.000Z

    This report provides a review of fire and vapor control practices used in the liquefied natural gas (LNG) industry. Specific objectives of this effort were to summarize the state-of-the-art of LNG fire and vapor control; define representative LNG facilities and their associated fire and vapor control systems; and develop an approach for a quantitative effectiveness evaluation of LNG fire and vapor control systems. In this report a brief summary of LNG physical properties is given. This is followed by a discussion of basic fire and vapor control design philosophy and detailed reviews of fire and vapor control practices. The operating characteristics and typical applications and application limitations of leak detectors, fire detectors, dikes, coatings, closed circuit television, communication systems, dry chemicals, water, high expansion foam, carbon dioxide and halogenated hydrocarbons are described. Summary descriptions of a representative LNG peakshaving facility and import terminal are included in this report together with typical fire and vapor control systems and their locations in these types of facilities. This state-of-the-art review identifies large differences in the application of fire and vapor control systems throughout the LNG industry.

  17. Quantitative organic vapor-particle sampler

    DOE Patents [OSTI]

    Gundel, Lara (Berkeley, CA); Daisey, Joan M. (Walnut Creek, CA); Stevens, Robert K. (Cary, NC)

    1998-01-01T23:59:59.000Z

    A quantitative organic vapor-particle sampler for sampling semi-volatile organic gases and particulate components. A semi-volatile organic reversible gas sorbent macroreticular resin agglomerates of randomly packed microspheres with the continuous porous structure of particles ranging in size between 0.05-10 .mu.m for use in an integrated diffusion vapor-particle sampler.

  18. 6, 80698095, 2006 Water vapor in Asian

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of Sciences, Beijing, China 2 National Center for Atmospheric Research, Boulder, CO, USA Received: 23 May 2006 vapor from European Center for Medium-Range Weather20 Forecasts (ECMWF) analyses. 1 Introduction Upper Tropospheric Water Vapor (UTWV) is a key greenhouse gas which exerts a major influence on the energy balance

  19. Integrated rig for the production of boron nitride nanotubes via the pressurized vapor-condenser method

    DOE Patents [OSTI]

    Smith, Michael W; Jordan, Kevin C

    2014-03-25T23:59:59.000Z

    An integrated production apparatus for production of boron nitride nanotubes via the pressure vapor-condenser method. The apparatus comprises: a pressurized reaction chamber containing a continuously fed boron containing target having a boron target tip, a source of pressurized nitrogen and a moving belt condenser apparatus; a hutch chamber proximate the pressurized reaction chamber containing a target feed system and a laser beam and optics.

  20. Light Transport in Cold Atoms and Thermal Decoherence G. Labeyrie,1,* D. Delande,2

    E-Print Network [OSTI]

    Light Transport in Cold Atoms and Thermal Decoherence G. Labeyrie,1,* D. Delande,2 R. Kaiser,1 experimentally and theoretically how coherent transport of light inside a cold atomic vapor is affected motivated by astrophysical purposes, wave transport in opaque media was first analyzed by means

  1. HANFORD CHEMICAL VAPORS WORKER CONCERNS & EXPOSURE EVALUATION

    SciTech Connect (OSTI)

    ANDERSON, T.J.

    2006-12-20T23:59:59.000Z

    Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors.

  2. An Alkali-Vapor Cell with Metal Coated Windows for Efficient Application of an Electric Field

    E-Print Network [OSTI]

    Sarkisyan, D; Guena, J; Lintz, M; Bouchiat, M A; Sarkisyan, David; Gu\\'{e}na, Jocelyne; Lintz, Michel; Bouchiat, Marie-Anne

    2005-01-01T23:59:59.000Z

    We describe the implementation of a cylindrical T-shaped alkali-vapor cell for laser spectroscopy in the presence of a longitudinal electric field. The two windows are used as two electrodes of the high-voltage assembly, which is made possible by a metallic coating which entirely covers the inner and outer sides of the windows except for a central area to let the laser beams in and out of the cell. This allows very efficient application of the electric field, up to 2 kV/cm in a rather dense superheated vapor, even when significant photoemission takes place at the windows during pulsed laser irradiation. The body of the cell is made of sapphire or alumina ceramic to prevent large currents resulting from surface conduction observed in cesiated glass cells. The technique used to attach the monocrystalline sapphire windows to the cell body causes minimal stress birefringence in the windows. In addition, reflection losses at the windows can be made very small. The vapor cell operates with no buffer gas and has no ...

  3. Stacked vapor fed amtec modules

    DOE Patents [OSTI]

    Sievers, Robert K. (North Huntingdon, PA)

    1989-01-01T23:59:59.000Z

    The present invention pertains to a stacked AMTEC module. The invention includes a tubular member which has an interior. The member is comprised of a ion conductor that substantially conducts ions relative to electrons, preferably a beta"-alumina solid electrolyte, positioned about the interior. A porous electrode for conducting electrons and allowing sodium ions to pass therethrough, and wherein electrons and sodium ions recombine to form sodium is positioned about the beta"-alumina solid electrolyte. The electrode is operated at a temperature and a pressure that allows the recombined sodium to vaporize. Additionally, an outer current collector grid for distributing electrons throughout the porous electrode is positioned about and contacts the porous electrode. Also included in the invention is transporting means for transporting liquid sodium to the beta"-alumina solid electrolyte of the tubular member. A transition piece is positioned about the interior of the member and contacts the transporting means. The transition piece divides the member into a first cell and a second cell such that each first and second cell has a beta"-alumina solid electrolyte, a first and second porous electrode and a grid. The transition piece conducts electrons from the interior of the tubular member. There is supply means for supplying sodium to the transporting means. Preferably the supply means is a shell which surrounds the tubular member and is operated at a temperature such that the vaporized sodium condenses thereon. Returning means for returning the condensed sodium from the shell to the transporting means provides a continuous supply of liquid sodium to the transporting means. Also, there are first conducting means for conducting electric current from the transition piece which extends through the shell, and second conducting means for conducting electric current to the grid of the first cell which extends through the shell.

  4. Measuring Atomic Properties with an Atom Interferometer

    E-Print Network [OSTI]

    Roberts, Tony David

    2006-06-28T23:59:59.000Z

    Two experiments are presented which measure atomic properties using an atom interferometer. The interferometer splits the sodium de Broglie wave into two paths,

  5. Quantitative Infrared Intensity Studies of Vapor-PhaseGlyoxal...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal, and 2,3-Butanedione (Diacetyl) with Quantitative Infrared Intensity Studies of Vapor-Phase Glyoxal,Methylglyoxal,...

  6. Absolute integrated intensities of vapor-phase hydrogen peroxide...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Absolute integrated intensities of vapor-phase hydrogen peroxide (H202) in the mid-infrared at atmospheric pressure. Absolute integrated intensities of vapor-phase hydrogen...

  7. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. | EMSL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Acidic Polymers for Chemical Vapor Sensing. Hydrogen-Bond Acidic Polymers for Chemical Vapor Sensing. Abstract: A review with 171 references. Hydrogen-bond acidic polymers for...

  8. MEASUREMENT OF ION BEAM FROM LASER ION SOURCE FOR RHIC Takeshi Kanesue, Kyushu University, Fukuoka 819-0395, Japan

    E-Print Network [OSTI]

    , vaporized and becomes plasma which is called laser ablation plasma then plasma expand adiabatically perpendicular to the target surface. Properties of Laser ablation plasma such as charge state distribution, and emittance of Au ions extracted from laser ablation plasma was measured. SINGLY CHARGED ION PRODUCTION We

  9. Investigation of the effect of water content, thickness and optical properties on laser ablation of biological tissue

    E-Print Network [OSTI]

    Vaidyanathan, Varadarajan

    1991-01-01T23:59:59.000Z

    HEAT TRANSFER WITHIN TISSUE DENATUREAT ION, COAGULATION AND NECROSIS OF CELLS B I 0 C MEri I C AL PROPERTIES ABLATION: VAPORIZATION AND PYROLYSIS Fig. 1. Events in laser ablation of tissue A. The use of lasers in medicine Lasers are being used...

  10. Gain narrowing in few-atom systems

    E-Print Network [OSTI]

    Tom Savels; Allard P. Mosk; Ad Lagendijk

    2006-05-31T23:59:59.000Z

    Using a density matrix approach, we study the simplest systems that display both gain and feedback: clusters of 2 to 5 atoms, one of which is pumped. The other atoms supply feedback through multiple scattering of light. We show that, if the atoms are in each other's near-field, the system exhibits large gain narrowing and spectral mode redistribution. The observed phenomena are more pronounced if the feedback is enhanced. Our system is to our knowledge the simplest exactly solvable microscopic system which shows the approach to laser oscillation.

  11. Hybrid Optical Pumping of Optically Dense Alkali-Metal Vapor without Quenching Gas

    SciTech Connect (OSTI)

    Romalis, M. V. [Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

    2010-12-10T23:59:59.000Z

    Optical pumping of an optically thick atomic vapor typically requires a quenching buffer gas, such as N{sub 2}, to prevent radiation trapping of unpolarized photons which would depolarize the atoms. We show that optical pumping of a trace contamination of Rb present in K metal results in a 4.5 times higher polarization of K than direct optical pumping of K in the absence of N{sub 2}. Such spin-exchange polarization transfer from optically thin species is useful in a variety of areas, including spin-polarized nuclear scattering targets and electron beams, quantum-nondemolition spin measurements, and ultrasensitive magnetometry.

  12. Laser peening for reducing hydrogen embrittlement

    DOE Patents [OSTI]

    Hackel, Lloyd A.; Zaleski, Tania M.; Chen, Hao-Lin; Hill, Michael R.; Liu, Kevin K.

    2010-05-25T23:59:59.000Z

    A laser peening process for the densification of metal surfaces and sub-layers and for changing surface chemical activities provides retardation of the up-take and penetration of atoms and molecules, particularly Hydrogen, which improves the lifetime of such laser peened metals. Penetration of hydrogen into metals initiates an embrittlement that leaves the material susceptible to cracking.

  13. Magneto-Optical Cooling of Atoms Mark G. Raizen1

    E-Print Network [OSTI]

    Raizen, Mark G.

    , it was not clear how to optimally integrate the above techniques, and a direct comparison with laser coolingMagneto-Optical Cooling of Atoms Mark G. Raizen1 , Dmitry Budker2,3 , Simon Rochester3 , Julia, Weizmann Institute of Science, Rehovot, Israel Abstract We propose an alternative method to laser cooling

  14. Laser Assisted Plasma Arc Welding

    SciTech Connect (OSTI)

    FUERSCHBACH,PHILLIP W.

    1999-10-05T23:59:59.000Z

    Experiments have been performed using a coaxial end-effecter to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (< 1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  15. LASER MATERIALS PROCESSING Wenwu Zhang, Ph.D.

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    Center Schenectady, New York Y. Lawrence Yao, Ph.D. Columbia University New York, New York (1. (1)34.2 UNDERSTANDING OF LASER ENERGY 34.2.1 Basic Principles of Lasers Lasers are photon energy medium, the resonator optics, the pumping system, and the cooling system. The atomic energy level

  16. Single-mode, frequency-stabilized LNA ring laser

    SciTech Connect (OSTI)

    Soletsky, P.A.; Bixler, D.L.; Dunning, F.B. (Department of Physics and the Rice Quantum Institute, Rice University, Houston, Texas 77251 (United States))

    1994-11-01T23:59:59.000Z

    A single-mode, frequency-stabilized LNA (lanthanum neodymium magnesium hexaluminate) ring laser developed for application in optical pumping and optical manipulation of He(2 [sup 3][ital S]) metastable atoms is described. This laser routinely provides output powers [approx gt]300 mW at 1.083 [mu]m when pumped with 5 W from an argon-ion laser.

  17. Laser-assisted nuclear photoeffect

    E-Print Network [OSTI]

    Anis Dadi; Carsten Müller

    2012-04-17T23:59:59.000Z

    Proton emission from nuclei via the nuclear photoeffect in the combined electromagnetic fields of a gamma-ray photon and an intense laser wave is studied. An S-matrix approach to the process is developed by utilizing methods known from the theory of nonperturbative laser-atom interactions. As a specific example, photo-proton ejection from halo nuclei is considered. We show that, due to the presence of the laser field, rich sideband structures arise in the photo-proton energy spectra. Their dependence on the parameters and relative orientation of the photon fields is discussed.

  18. Recovering hydrocarbons from hydrocarbon-containing vapors

    DOE Patents [OSTI]

    Mirza, Zia I. (La Verne, CA); Knell, Everett W. (Los Alamitos, CA); Winter, Bruce L. (Danville, CA)

    1980-09-30T23:59:59.000Z

    Values are recovered from a hydrocarbon-containing vapor by contacting the vapor with quench liquid consisting essentially of hydrocarbons to form a condensate and a vapor residue, the condensate and quench fluid forming a combined liquid stream. The combined liquid stream is mixed with a viscosity-lowering liquid to form a mixed liquid having a viscosity lower than the viscosity of the combined liquid stream to permit easy handling of the combined liquid stream. The quench liquid is a cooled portion of the mixed liquid. Viscosity-lowering liquid is separated from a portion of the mixed liquid and cycled to form additional mixed liquid.

  19. VOLUME 82, NUMBER 26 P HY S I CA L R E V I E W L E T T E R S 28 JUNE 1999 LaserDriven Atomic Pump

    E-Print Network [OSTI]

    , and by the wind force Fw caused by the reflection of conduction electrons from these atoms. Since F d usually, as schematically depicted in Fig. 1, by exerting on it the wind force Fw , due to the absorption of electron are driven by the direct force F d due to the external field that is locally modified at the atomic site

  20. VOLUME 82, NUMBER 26 P H Y S I C A L R E V I E W L E T T E R S 28 JUNE 1999 Laser-Driven Atomic Pump

    E-Print Network [OSTI]

    by the direct force Fd due to the external field that is locally modified at the atomic site, and by the wind in Fig. 1, by exerting on it the wind force Fw, due to the absorption of electron momenta. The direct force Fw caused by the reflection of conduction electrons from these atoms. Since Fd usually dominates

  1. Mobile and remote inertial sensing with atom interferometers

    E-Print Network [OSTI]

    Boyer, Edmond

    Mobile and remote inertial sensing with atom interferometers B. Barrett, P.-A. Gominet, E. Cantin for equivalence principle tests. We also discuss fu- ture applications of this technology, such as remote sensing on laser-cooling and trapping neutral atoms [6, 7, 8, 9, 10] which eventually led to two nobel prizes

  2. Experimental Investigation of Excited-State Lifetimes in Atomic Ytterbium

    SciTech Connect (OSTI)

    Bowers, C.J.; Budker, D.; Commins, E.D.; DeMille, D.; Freedman, S.J.; Nguyen, A.-T.; Shang, S.-Q.; /UC, Berkeley; Zolotorev, M.; /SLAC

    2011-11-15T23:59:59.000Z

    Lifetimes of 21 excited states in atomic Yb were measured using time-resolved fluorescence detection following pulsed laser excitation. The lifetime of the 4f{sup 14}5d6s {sup 3}D{sub 1} state, which is of particular importance for a proposed study of parity nonconservation in atoms, was measured to be 380(30) ns.

  3. Novel rubidium atomic beam with an alkali dispenser source

    SciTech Connect (OSTI)

    Roach, Timothy M.; Henclewood, Dwayne [College of the Holy Cross, Worcester, Massachusetts 01610 (United States)

    2004-11-01T23:59:59.000Z

    We describe a novel atomic beam apparatus with a resistively heated alkali dispenser source and a cold-pumped intermediate chamber. Using laser fluorescence spectroscopy we have measured the atomic density to be 3x10{sup 11} atoms/m{sup 3} and the total flux to be 5x10{sup 8} atoms/s in a 0.3 cm diameter beam. We have also characterized the velocity distribution of the source based on the Doppler-shifted fluorescence spectrum. The compact geometry, flexibility, and simplicity of the beam may make it useful as an optical frequency reference or for experiments on atom-cooling.

  4. Roles of additives and surface control in slurry atomization

    SciTech Connect (OSTI)

    Tsai, S.C.

    1990-07-10T23:59:59.000Z

    Airblast atomization of micronized coal water slurry is carried out using twin-fluid jet atomizers of various distributor designs. Drop size and size distribution are measured using the laser diffraction technique. We found that the atomized drop sizes of micronized coal water slurries substantially decrease as the atomizing air pressure exceeds a threshold value. We also found that the atomized drop size, represented by the mass median diameter (MMD) can be described by the wave mechanism-based models in terms of three non-dimensional groups, namely, slurry-to-air mass ratio, the Weber number, and the Ohnesorge number. 11 refs.

  5. REPORT ON ATOMIZATION TESTS FOR PROJECT TITLED - BIODIESEL BLENDS IN MICROTURBINE.

    SciTech Connect (OSTI)

    KRISHNA,C.R.

    2007-01-01T23:59:59.000Z

    The injectors for the Capstone turbine have the general design shown in figure 1 below. It consists of an airblast atomizer with a cylindrical fuel nozzle and an annular air passage surrounding it. The airblast atomizer is surrounded by a 'mixing tube' with circular holes just downstream of the atomizer outlet and swirler holes further downstream. During operation, these holes bring 'hot' air/gases to help vaporize and provide premixed fuel and air for combustion downstream of the 'mixing' tube.

  6. Optical penetration sensor for pulsed laser welding

    DOE Patents [OSTI]

    Essien, Marcelino (Albuquerque, NM); Keicher, David M. (Albuquerque, NM); Schlienger, M. Eric (Albuquerque, NM); Jellison, James L. (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    An apparatus and method for determining the penetration of the weld pool created from pulsed laser welding and more particularly to an apparatus and method of utilizing an optical technique to monitor the weld vaporization plume velocity to determine the depth of penetration. A light source directs a beam through a vaporization plume above a weld pool, wherein the plume changes the intensity of the beam, allowing determination of the velocity of the plume. From the velocity of the plume, the depth of the weld is determined.

  7. Quantum to Classical Transition in a Single-Ion Laser

    E-Print Network [OSTI]

    François Dubin; Carlos Russo; Helena G. Barros; Andreas Stute; Christoph Becher; Piet O. Schmidt; Rainer Blatt

    2010-02-18T23:59:59.000Z

    Stimulated emission of photons from a large number of atoms into the mode of a strong light field is the principle mechanism for lasing in "classical" lasers. The onset of lasing is marked by a threshold which can be characterised by a sharp increase in photon flux as a function of external pumping strength. The same is not necessarily true for the fundamental building block of a laser: a single trapped atom interacting with a single optical radiation mode. It has been shown that such a "quantum" laser can exhibit thresholdless lasing in the regime of strong coupling between atom and radiation field. However, although theoretically predicted, a threshold at the single-atom level could not be experimentally observed so far. Here, we demonstrate and characterise a single-atom laser with and without threshold behaviour by changing the strength of atom-light field coupling. We observe the establishment of a laser threshold through the accumulation of photons in the optical mode even for a mean photon number substantially lower than for the classical case. Furthermore, self-quenching occurs for very strong external pumping and constitutes an intrinsic limitation of single-atom lasers. Moreover, we find that the statistical properties of the emitted light can be adjusted for weak external pumping, from the quantum to the classical domain. Our observations mark an important step towards fundamental understanding of laser operation in the few-atom limit including systems based on semiconductor quantum dots or molecules.

  8. Atomic Rydberg Reservoirs for Polar Molecules

    E-Print Network [OSTI]

    Zhao, Bo; Pupillo, Guido; Zoller, Peter

    2011-01-01T23:59:59.000Z

    We discuss laser dressed dipolar and Van der Waals interactions between atoms and polar molecules, so that a cold atomic gas with laser admixed Rydberg levels acts as a designed reservoir for both elastic and inelastic collisional processes. The elastic scattering channel is characterized by large elastic scattering cross sections and repulsive shields to protect from close encounter collisions. In addition, we discuss a dissipative (inelastic) collision where a spontaneously emitted photon carries away (kinetic) energy of the collision partners, thus providing a significant energy loss in a single collision. This leads to the scenario of rapid thermalization and cooling of a molecule in the mK down to the \\mu K regime by cold atoms.

  9. Atomic Rydberg Reservoirs for Polar Molecules

    E-Print Network [OSTI]

    Bo Zhao; Alexander Glätzle; Guido Pupillo; Peter Zoller

    2011-12-18T23:59:59.000Z

    We discuss laser dressed dipolar and Van der Waals interactions between atoms and polar molecules, so that a cold atomic gas with laser admixed Rydberg levels acts as a designed reservoir for both elastic and inelastic collisional processes. The elastic scattering channel is characterized by large elastic scattering cross sections and repulsive shields to protect from close encounter collisions. In addition, we discuss a dissipative (inelastic) collision where a spontaneously emitted photon carries away (kinetic) energy of the collision partners, thus providing a significant energy loss in a single collision. This leads to the scenario of rapid thermalization and cooling of a molecule in the mK down to the \\mu K regime by cold atoms.

  10. Chemical vapor infiltration using microwave energy

    DOE Patents [OSTI]

    Devlin, David J. (Los Alamos, NM); Currier, Robert P. (Los Alamos, NM); Laia, Jr., Joseph R. (Los Alamos, NM); Barbero, Robert S. (Santa Cruz, NM)

    1993-01-01T23:59:59.000Z

    A method for producing reinforced ceramic composite articles by means of chemical vapor infiltration and deposition in which an inverted temperature gradient is utilized. Microwave energy is the source of heat for the process.

  11. Chemical vapor deposition of functionalized isobenzofuran polymers

    E-Print Network [OSTI]

    Olsson, Ylva Kristina

    2007-01-01T23:59:59.000Z

    This thesis develops a platform for deposition of polymer thin films that can be further tailored by chemical surface modification. First, we explore chemical vapor deposition of functionalized isobenzofuran films using ...

  12. An advanced vapor-compression desalination system 

    E-Print Network [OSTI]

    Lara Ruiz, Jorge Horacio Juan

    2006-04-12T23:59:59.000Z

    Currently, the two dominant desalination methods are reverse osmosis (RO) and multi-stage flash (MSF). RO requires large capital investment and maintenance, whereas MSF is too energy intensive. An innovative vapor-compression desalination system...

  13. Modeling of LNG Pool Spreading and Vaporization

    E-Print Network [OSTI]

    Basha, Omar 1988-

    2012-11-20T23:59:59.000Z

    In this work, a source term model for estimating the rate of spreading and vaporization of LNG on land and sea is introduced. The model takes into account the composition changes of the boiling mixture, the varying thermodynamic properties due...

  14. Chemical vapor deposition of antimicrobial polymer coatings

    E-Print Network [OSTI]

    Martin, Tyler Philip, 1977-

    2007-01-01T23:59:59.000Z

    There is large and growing interest in making a wide variety of materials and surfaces antimicrobial. Initiated chemical vapor deposition (iCVD), a solventless low-temperature process, is used to form thin films of polymers ...

  15. Solid-Vapor Sorption Refrigeration Systems 

    E-Print Network [OSTI]

    Graebel, W.; Rockenfeller, U.; Kirol, L.

    1991-01-01T23:59:59.000Z

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract.... Complex compounds have a number of advantages as working media, including: 43 SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL Engineer Rocky Research Boulder city, NV DR. UWE ROCKENFELLER President Rocky Research Boulder city, NV MR...

  16. ccsd-00005837,version2-10Jul2005 Partially ferromagnetic electromagnet for trapping and cooling neutral atoms to

    E-Print Network [OSTI]

    Boyer, Edmond

    lasers. INTRODUCTION The realization of Bose-Einstein condensates (BECs) of a dilute gas of trapped atoms of 87 Rb atoms to quantum degeneracy. Pure Bose-Einstein condensates containing 106 atoms are routinely, 9]. It is therefore expected that the use of Bose-Einstein condensed atoms will advance the field

  17. Two-color Laser Desorption of Nanostructured MgO Thin Films....

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Two-color Laser Desorption of Nanostructured MgO Thin Films. Two-color Laser Desorption of Nanostructured MgO Thin Films. Abstract: Neutral magnesium atom emission from...

  18. Apparatus for precision micromachining with lasers

    DOE Patents [OSTI]

    Chang, J.J.; Dragon, E.P.; Warner, B.E.

    1998-04-28T23:59:59.000Z

    A new material processing apparatus using a short-pulsed, high-repetition-rate visible laser for precision micromachining utilizes a near diffraction limited laser, a high-speed precision two-axis tilt-mirror for steering the laser beam, an optical system for either focusing or imaging the laser beam on the part, and a part holder that may consist of a cover plate and a back plate. The system is generally useful for precision drilling, cutting, milling and polishing of metals and ceramics, and has broad application in manufacturing precision components. Precision machining has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratios up to 1:40 have been consistently drilled with good surface finish on a variety of metals. Micromilling and microdrilling on ceramics using a 250 W copper vapor laser have also been demonstrated with good results. Materialographic sections of machined parts show little (submicron scale) recast layer and heat affected zone. 1 fig.

  19. Apparatus for precision micromachining with lasers

    DOE Patents [OSTI]

    Chang, Jim J. (Dublin, CA); Dragon, Ernest P. (Danville, CA); Warner, Bruce E. (Pleasanton, CA)

    1998-01-01T23:59:59.000Z

    A new material processing apparatus using a short-pulsed, high-repetition-rate visible laser for precision micromachining utilizes a near diffraction limited laser, a high-speed precision two-axis tilt-mirror for steering the laser beam, an optical system for either focusing or imaging the laser beam on the part, and a part holder that may consist of a cover plate and a back plate. The system is generally useful for precision drilling, cutting, milling and polishing of metals and ceramics, and has broad application in manufacturing precision components. Precision machining has been demonstrated through percussion drilling and trepanning using this system. With a 30 W copper vapor laser running at multi-kHz pulse repetition frequency, straight parallel holes with size varying from 500 microns to less than 25 microns and with aspect ratios up to 1:40 have been consistently drilled with good surface finish on a variety of metals. Micromilling and microdrilling on ceramics using a 250 W copper vapor laser have also been demonstrated with good results. Materialogroaphic sections of machined parts show little (submicron scale) recast layer and heat affected zone.

  20. Active optical frequency standards using cold atoms: perspectives and challenges

    E-Print Network [OSTI]

    Kazakov, Georgy A

    2015-01-01T23:59:59.000Z

    We consider various approaches to the creation of a high-stability active optical frequency standard, where the atomic ensemble itself produces a highly stable and accurate frequency signal. The short-time frequency stability of such standards may overcome the stability of lasers stabilized to macroscopic cavities which are used as local oscillators in the modern optical frequency standard systems. The main idea is to create a "superradiant" laser operating deep in the bad cavity regime, where the decay rate of the cavity field significantly exceeds the decoherence rate of the lasing transition. Two main approaches towards the realization of an active optical frequency standard have been proposed already: the optical lattice laser, and the atomic beam laser. We consider these and some alternative approaches, and discuss the parameters for atomic ensembles necessary to attain the metrology relevant level of short-time frequency stability, and various effects and main challenges critical for practical implement...

  1. Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser/Time-of-Flight Mass Spectrometry

    E-Print Network [OSTI]

    Goddard III, William A.

    Prediction of the Size Distributions of Methanol-Ethanol Clusters Detected in VUV Laser distributions and geometries of vapor clusters equilibrated with methanol-ethanol (Me-Et) liquid mixtures were distributions of vapor clusters equilibrated with liquids, ranging from neat alcohols1,2 to methanol-ethanol (Me

  2. Very-high-order harmonic generation from Ar atoms and Ar+ ions in superintense pulsed laser fields: An ab initio self-interaction-free time-dependent density-functional approach

    E-Print Network [OSTI]

    Carrera, Juan J.; Chu, Shih-I; Tong, Xiao-Min

    2005-06-21T23:59:59.000Z

    We present an ab initio nonpertubative investigation of the mechanisms responsible for the production of very-high-order harmonic generation (HHG) from Ar atoms and Ar+ ions by means of the self-interaction-free time-dependent density...

  3. Driven Ratchets for Cold Atoms

    E-Print Network [OSTI]

    Renzoni, F

    2011-01-01T23:59:59.000Z

    Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical systems, and indeed ratchets have been realized with a variety of solid state devices, with optical trap setups as well as with synthetic molecules and granular gases. The present article reviews recent experimental realizations of ac driven ratchets with cold atoms in driven optical lattices. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system allowed us to realize experimentally rocking and gating ratchets, and to precisely investigate the relationship between symmetry and transport in these ratchets, both for the case of periodic and quasiperiodic driving.

  4. Driven Ratchets for Cold Atoms

    E-Print Network [OSTI]

    F. Renzoni

    2011-12-05T23:59:59.000Z

    Brownian motors, or ratchets, are devices which "rectify" Brownian motion, i.e. they can generate a current of particles out of unbiased fluctuations. The ratchet effect is a very general phenomenon which applies to a wide range of physical systems, and indeed ratchets have been realized with a variety of solid state devices, with optical trap setups as well as with synthetic molecules and granular gases. The present article reviews recent experimental realizations of ac driven ratchets with cold atoms in driven optical lattices. This is quite an unusual system for a Brownian motor as there is no a real thermal bath, and both the periodic potential for the atoms and the fluctuations are determined by laser fields. Such a system allowed us to realize experimentally rocking and gating ratchets, and to precisely investigate the relationship between symmetry and transport in these ratchets, both for the case of periodic and quasiperiodic driving.

  5. Page 1Laser Safety Training Laser Institute of America Laser Safety Laser Institute of America

    E-Print Network [OSTI]

    Farritor, Shane

    Page 1Laser Safety Training © Laser Institute of America 1 Laser Safety © Laser Institute of America Laser Safety: Hazards, Bioeffects, and Control Measures Laser Institute of America Gus Anibarro Education Manager 2Laser Safety © Laser Institute of America Laser Safety Overview Laser Safety Accidents

  6. axial free-electron laser: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    but works at shortof the development of electron tubes and atomic lasers. Theyelectron energy and using higher harmonics, and efficiencies of 60% were common. While the Motz...

  7. alamos free-electron laser: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    but works at shortof the development of electron tubes and atomic lasers. Theyelectron energy and using higher harmonics, and efficiencies of 60% were common. While the Motz...

  8. Experimental Realization of an Optical One-Way Barrier for Neutral Atoms Jeremy J. Thorn, Elizabeth A. Schoene, Tao Li, and Daniel A. Steck

    E-Print Network [OSTI]

    Steck, Daniel A.

    atoms and molecules not amenable to standard laser-cooling techniques. In our experiment, atoms: atoms falling into ``dark states'' decouple from the cooling lasers. However, cooling techniques based but reflected from the other, is a realization of Maxwell's demon and has important implications for cooling

  9. Laser Telecommunication timeLaser beam

    E-Print Network [OSTI]

    La Rosa, Andres H.

    Laser Telecommunication Experiment Laser time Laser beam intensity timeLaser beam Laser battery Laser connected to a circuit without a modulator. Bottom graph illustrates what happen when a modulating signal is superimposed to the DC voltage driving the laser Laser beam intensity DC Input voltage DC

  10. Nitric Oxide Production from Surface Recombination of Oxygen and Nitrogen Atoms

    E-Print Network [OSTI]

    Martín, Pino

    of hypersonic reentry vehicles. In the Earth's atmosphere, oxygen and nitrogen atoms are generated in the shock1 Nitric Oxide Production from Surface Recombination of Oxygen and Nitrogen Atoms Dusan A. Pejakovi from the recombination of oxygen and nitrogen atoms on quartz. The experiments employ two-photon laser

  11. Laser theory in manifest Lindblad form

    E-Print Network [OSTI]

    C. Henkel

    2007-05-06T23:59:59.000Z

    We discuss the laser theory for a single-mode laser with nonlinear gain. We focus in particular on a micromaser which is pumped with a dilute beam of excited atoms crossing the laser cavity. In the weak-coupling regime, an expansion in the coupling strength is developed that preserves the Lindblad form of the master equation, securing the positivity of the density matrix. This expansion breaks rapidly down above threshold. This can be improved with an alternative approach, not restricted to weak coupling: the Lindblad operators are expanded in orthogonal polynomials adapted to the probability distribution for the atom-laser interaction time. Results for the photon statistics and the laser linewidth illustrate the theory.

  12. Stationary light in cold atomic gases

    E-Print Network [OSTI]

    Gor Nikoghosyan; Michael Fleischhauer

    2009-09-16T23:59:59.000Z

    We discuss stationary light created by a pair of counter-propagating control fields in Lambda-type atomic gases with electromagnetically induced transparency for the case of negligible Doppler broadening. In this case the secular approximation used in the discussion of stationary light in hot vapors is no longer valid. We discuss the quality of the effective light-trapping system and show that in contrast to previous claims it is finite even for vanishing ground-state dephasing. The dynamics of the photon loss is in general non exponential and can be faster or slower than in hot gases.

  13. Laser microphone

    DOE Patents [OSTI]

    Veligdan, James T. (Manorville, NY)

    2000-11-14T23:59:59.000Z

    A microphone for detecting sound pressure waves includes a laser resonator having a laser gain material aligned coaxially between a pair of first and second mirrors for producing a laser beam. A reference cell is disposed between the laser material and one of the mirrors for transmitting a reference portion of the laser beam between the mirrors. A sensing cell is disposed between the laser material and one of the mirrors, and is laterally displaced from the reference cell for transmitting a signal portion of the laser beam, with the sensing cell being open for receiving the sound waves. A photodetector is disposed in optical communication with the first mirror for receiving the laser beam, and produces an acoustic signal therefrom for the sound waves.

  14. Transverse-type laser assembly using induced electrical discharge excitation and method

    DOE Patents [OSTI]

    Ault, E.R.

    1994-04-19T23:59:59.000Z

    A transverse-type laser assembly is disclosed herein. This assembly defines a laser cavity containing a vapor or gaseous substance which lases when subjected to specific electrical discharge excitation between a pair of spaced-apart electrodes located within the cavity in order to produce a source of light. An arrangement located entirely outside the laser cavity is provided for inducing a voltage across the electrodes within the cavity sufficient to provide the necessary electrical discharge excitation to cause a vapor substance between the electrodes to lase. 3 figures.

  15. Vapor scavenging by atmospheric aerosol particles

    SciTech Connect (OSTI)

    Andrews, E.

    1996-05-01T23:59:59.000Z

    Particle growth due to vapor scavenging was studied using both experimental and computational techniques. Vapor scavenging by particles is an important physical process in the atmosphere because it can result in changes to particle properties (e.g., size, shape, composition, and activity) and, thus, influence atmospheric phenomena in which particles play a role, such as cloud formation and long range transport. The influence of organic vapor on the evolution of a particle mass size distribution was investigated using a modified version of MAEROS (a multicomponent aerosol dynamics code). The modeling study attempted to identify the sources of organic aerosol observed by Novakov and Penner (1993) in a field study in Puerto Rico. Experimentally, vapor scavenging and particle growth were investigated using two techniques. The influence of the presence of organic vapor on the particle`s hydroscopicity was investigated using an electrodynamic balance. The charge on a particle was investigated theoretically and experimentally. A prototype apparatus--the refractive index thermal diffusion chamber (RITDC)--was developed to study multiple particles in the same environment at the same time.

  16. Laser ignition

    DOE Patents [OSTI]

    Early, James W.; Lester, Charles S.

    2004-01-13T23:59:59.000Z

    Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.

  17. Specific energy for pulsed laser rock drilling.

    SciTech Connect (OSTI)

    Xu, Z.; Reed, C. B.; Kornecki, G.; Gahan, B. C.; Parker, R. A.; Batarseh, S.; Graves, R. M.; Figueroa, H.; Skinner, N.; Technology Development

    2003-02-01T23:59:59.000Z

    Application of advanced high power laser technology to oil and gas well drilling has been attracting significant research interests recently among research institutes, petroleum industries, and universities. Potential laser or laser-aided oil and gas well drilling has many advantages over the conventional rotary drilling, such as high penetration rate, reduction or elimination of tripping, casing, and bit costs, and enhanced well control, perforating and side-tracking capabilities. The energy required to remove a unit volume of rock, namely the specific energy (SE), is a critical rock property data that can be used to determine both the technical and economic feasibility of laser oil and gas well drilling. When a high power laser beam is applied on a rock, it can remove the rock by thermal spallation, melting, or vaporization depending on the applied laser energy and the way the energy is applied. The most efficient rock removal mechanism would be the one that requires the minimum energy to remove a unit volume of rock. Samples of sandstone, shale, and limestone were prepared for laser beam interaction with a 1.6 kW pulsed Nd:yttrium-aluminum-garnet laser beam to determine how the beam size, power, repetition rate, pulse width, exposure time and energy can affect the amount of energy transferred to the rock for the purposes of spallation, melting, and vaporization. The purpose of the laser rock interaction experiment was to determine the optimal parameters required to remove a maximum rock volume from the samples while minimizing energy input. Absorption of radiant energy from the laser beam gives rise to the thermal energy transfer required for the destruction and removal of the rock matrix. Results from the tests indicate that each rock type has a set of optimal laser parameters to minimize specific energy (SE) values as observed in a set of linear track and spot tests. As absorbed energy outpaces heat diffusion by the rock matrix, local temperatures can rise to the melting points of the minerals and quickly increase observed SE values. Tests also clearly identified the spallation and melting zones for shale samples while changing the laser power. The lowest SE values are obtained in the spalling zone just prior to the onset of mineral melt. The laser thermally spalled and saw mechanically cut rocks show similarity of surface microstructure. The study also found that increasing beam repetition rate within the same material removal mechanism would increase the material removal rate, which is believed due to an increase of maximum temperature, thermal cycling frequency, and intensity of laser-driven shock wave within the rock.

  18. Laser induced thermophoresis and particulate deposition efficiency

    SciTech Connect (OSTI)

    Cipolla, J.; Morse, T.F.; Wang, C.Y.

    1983-07-01T23:59:59.000Z

    The interaction of laser radiation and an absorbing aerosol in a tube flow has been considered. The aerosol is produced by external heating of reactants as in the MCVD (Modified Chemical Vapor Deposition) process to produce submicron size particles in the manufacture of optical fiber preforms. These are subsequently deposited by thermophoretic forces on the inner wall of the tube as they are convected by a Poiseuille velocity profile. Axial laser radiation in the tube interacts with the absorbing particles, and the laser heating of the gas induces additional thermophoretic forces that markedly increase the efficiency of particulate deposition. A particle concentration dependent absorption coefficient that appears in the energy equation couples the energy equation to the equation of particle conservation, so that a non-linear set of coupled partial integrodifferential equations must be solved. Numerical solutions for aerosol particle trajectories, and thus deposition efficiencies, have been obtained. It is shown that laser enhanced thermophoresis markedly improves the deposition efficiency.

  19. Method and Apparatus for Concentrating Vapors for Analysis

    DOE Patents [OSTI]

    Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

    2008-10-07T23:59:59.000Z

    An apparatus and method are disclosed for pre-concentrating gaseous vapors for analysis. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable. Vapors sorbed and concentrated within the bed of the apparatus can be thermally desorbed achieving at least partial separation of vapor mixtures. The apparatus is suitable, e.g., for preconcentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than for direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications.

  20. Laser device

    DOE Patents [OSTI]

    Scott, Jill R. (Idaho Falls, ID); Tremblay, Paul L. (Idaho Falls, ID)

    2007-07-10T23:59:59.000Z

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  1. Remote generation of entanglement for individual atoms via optical fibers

    E-Print Network [OSTI]

    Y. Q. Guo; H. Y. Zhong; Y. H. Zhang; H. S. Song

    2008-05-29T23:59:59.000Z

    The generation of atomic entanglement is discussed in a system that atoms are trapped in separate cavities which are connected via optical fibers. Two distant atoms can be projected to Bell-state by synchronized turning off the local laser fields and then performing a single quantum measurement by a distant controller. The distinct advantage of this scheme is that it works in a regime that $\\Delta\\approx\\kappa\\gg g$, which makes the scheme insensitive to cavity strong leakage. Moreover, the fidelity is not affected by atomic spontaneous emission.

  2. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2003-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.

  3. Adsorption of water vapor on reservoir rocks

    SciTech Connect (OSTI)

    Not Available

    1993-07-01T23:59:59.000Z

    Progress is reported on: adsorption of water vapor on reservoir rocks; theoretical investigation of adsorption; estimation of adsorption parameters from transient experiments; transient adsorption experiment -- salinity and noncondensible gas effects; the physics of injection of water into, transport and storage of fluids within, and production of vapor from geothermal reservoirs; injection optimization at the Geysers Geothermal Field; a model to test multiwell data interpretation for heterogeneous reservoirs; earth tide effects on downhole pressure measurements; and a finite-difference model for free surface gravity drainage well test analysis.

  4. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, T.

    1988-03-15T23:59:59.000Z

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself. 4 figs.

  5. Thermal electric vapor trap arrangement and method

    DOE Patents [OSTI]

    Alger, Terry (Tracy, CA)

    1988-01-01T23:59:59.000Z

    A technique for trapping vapor within a section of a tube is disclosed herein. This technique utilizes a conventional, readily providable thermal electric device having a hot side and a cold side and means for powering the device to accomplish this. The cold side of this device is positioned sufficiently close to a predetermined section of the tube and is made sufficiently cold so that any condensable vapor passing through the predetermined tube section is condensed and trapped, preferably within the predetermined tube section itself.

  6. Free-Electron Laser FLASH Injector Laser

    E-Print Network [OSTI]

    FLASH. Free-Electron Laser in Hamburg FLASH Injector Laser Laser 1 Laser 2 Next steps Siegfried | FLASH Meeting | 16-Nov-2009 FLASH. Free-Electron Laser in Hamburg Laser 1 System Overview fround trip A 541 (2005) 467­477 #12;Siegfried Schreiber | FLASH Meeting | 16-Nov-2009 FLASH. Free-Electron Laser

  7. Atom chip apparatus for experiments with ultracold rubidium and potassium gases

    SciTech Connect (OSTI)

    Ivory, M. K.; Ziltz, A. R.; Fancher, C. T.; Pyle, A. J.; Sensharma, A.; Chase, B.; Field, J. P.; Garcia, A.; Aubin, S., E-mail: saaubi@wm.edu [Department of Physics, College of William and Mary, Williamsburg, Virginia 23187 (United States); Jervis, D. [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)] [Department of Physics, University of Toronto, Toronto, Ontario M5S 1A7 (Canada)

    2014-04-15T23:59:59.000Z

    We present a dual chamber atom chip apparatus for generating ultracold {sup 87}Rb and {sup 39}K atomic gases. The apparatus produces quasi-pure Bose-Einstein condensates of 10{sup 4} {sup 87}Rb atoms in an atom chip trap that features a dimple and good optical access. We have also demonstrated production of ultracold {sup 39}K and subsequent loading into the chip trap. We describe the details of the dual chamber vacuum system, the cooling lasers, the magnetic trap, the multicoil magnetic transport system, the atom chip, and two optical dipole traps. Due in part to the use of light-induced atom desorption, the laser cooling chamber features a sufficiently good vacuum to also support optical dipole trap-based experiments. The apparatus is well suited for studies of atom-surface forces, quantum pumping and transport experiments, atom interferometry, novel chip-based traps, and studies of one-dimensional many-body systems.

  8. Feedback Cooling of a Single Neutral Atom

    E-Print Network [OSTI]

    Markus Koch; Christian Sames; Alexander Kubanek; Matthias Apel; Maximilian Balbach; Alexei Ourjoumtsev; Pepijn W. H. Pinkse; Gerhard Rempe

    2010-10-15T23:59:59.000Z

    We demonstrate feedback cooling of the motion of a single rubidium atom trapped in a high-finesse optical resonator to a temperature of about 160 \\mu K. Time-dependent transmission and intensity-correlation measurements prove the reduction of the atomic position uncertainty. The feedback increases the 1/e storage time into the one second regime, 30 times longer than without feedback. Feedback cooling therefore rivals state-of-the-art laser cooling, but with the advantages that it requires less optical access and exhibits less optical pumping.

  9. Atom trap trace analysis of krypton isotopes

    SciTech Connect (OSTI)

    Bailey, K.; Chen, C. Y.; Du, X.; Li, Y. M.; Lu, Z.-T.; O'Connor, T. P.; Young, L.

    1999-11-17T23:59:59.000Z

    A new method of ultrasensitive isotope trace analysis has been developed. This method, based on the technique of laser manipulation of neutral atoms, has been used to count individual {sup 85}Kr and {sup 81}Kr atoms present in a natural krypton gas sample with isotopic abundances in the range of 10{sup {minus}11} and 10{sup {minus}13}, respectively. This method is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 x 10{sup {minus}7}. System improvements could increase the efficiency by many orders of magnitude.

  10. atom-atom collisions: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Atomic Safronova, Marianna 3 Atom-atom correlations in colliding Bose-Einstein condensates Quantum Physics (arXiv) Summary: We analyze atom-atom correlations in the s-wave...

  11. Possible applications of powerful pulsed CO{sub 2}-lasers in tokamak reactors

    SciTech Connect (OSTI)

    Nastoyashchii, A.F.; Morozov, I.N. [Troitsk Inst. for Innovation and Fusion Research, Moscow (Russian Federation); Hassanein, A. [Argonne National Lab., IL (United States)

    1998-08-01T23:59:59.000Z

    Applications of powerful pulsed CO{sub 2}-lasers for injection of fuel tablets or creation of a protective screen from the vapor of light elements to protect against the destruction of plasma-facing components are discussed, and the corresponding laser parameters are determined. The possibility of using CO{sub 2}-lasers in modeling the phenomena of powerful and energetic plasma fluxes interaction with a wall, as in the case of a plasma disruption, is considered.

  12. VOLUME 84, NUMBER 17 P H Y S I C A L R E V I E W L E T T E R S 24 APRIL 2000 Laser Cooling of Atoms, Ions, or Molecules by Coherent Scattering

    E-Print Network [OSTI]

    Vuletic, Vladan

    and is accompanied by strong heating due to force fluctuations [5]. In this Letter, we point out a general optical, and for strongly coupled single atoms heating has been observed recently [10]. In contrast to previous proposals-frequency beam coupling to all transitions simulta- neously is prevented by the requirement for Doppler cool- ing

  13. Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions 

    E-Print Network [OSTI]

    Kirol, L.

    1987-01-01T23:59:59.000Z

    Chemical heat pumps utilizing liquid-vapor reactions can be configured in forms analogous to electric drive vapor-compression heat pumps and heat activated absorption heat pumps. Basic thermodynamic considerations eliminate some heat pumps and place...

  14. Moisture Durability of Vapor Permeable Insulating Sheathing (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2013-10-01T23:59:59.000Z

    In this project, Building America team Building Science Corporation researched some of the ramifications of using exterior, vapor permeable insulation on retrofit walls with vapor permeable cavity insulation. Retrofit strategies are a key factor in reducing exterior building stock consumption.

  15. Vapor intrusion modeling : limitations, improvements, and value of information analyses

    E-Print Network [OSTI]

    Friscia, Jessica M. (Jessica Marie)

    2014-01-01T23:59:59.000Z

    Vapor intrusion is the migration of volatile organic compounds (VOCs) from a subsurface source into the indoor air of an overlying building. Vapor intrusion models, including the Johnson and Ettinger (J&E) model, can be ...

  16. OPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL

    E-Print Network [OSTI]

    Stanford University

    OPTIMIZATION OF INJECTION INTO VAPOR-DOMINATED GEOTHERMAL RESERVOIRS CONSIDERING ADSORPTION governing the behavior of vapor- dominated geothermal reservoirs. These mechanisms affect both was to determine the most effective injection strategy once these two effects are considered. Geothermal reservoir

  17. Ultrashort pulse laser deposition of thin films

    DOE Patents [OSTI]

    Perry, Michael D. (Livermore, CA); Banks, Paul S. (Livermore, CA); Stuart, Brent C. (Fremont, CA)

    2002-01-01T23:59:59.000Z

    Short pulse PLD is a viable technique of producing high quality films with properties very close to that of crystalline diamond. The plasma generated using femtosecond lasers is composed of single atom ions with no clusters producing films with high Sp.sup.3 /Sp.sup.2 ratios. Using a high average power femtosecond laser system, the present invention dramatically increases deposition rates to up to 25 .mu.m/hr (which exceeds many CVD processes) while growing particulate-free films. In the present invention, deposition rates is a function of laser wavelength, laser fluence, laser spot size, and target/substrate separation. The relevant laser parameters are shown to ensure particulate-free growth, and characterizations of the films grown are made using several diagnostic techniques including electron energy loss spectroscopy (EELS) and Raman spectroscopy.

  18. Advancing Explosives Detection Capabilities: Vapor Detection

    ScienceCinema (OSTI)

    Atkinson, David

    2014-07-24T23:59:59.000Z

    A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

  19. Vaporization of synthetic fuels. Final report. [Thesis

    SciTech Connect (OSTI)

    Sirignano, W.A.; Yao, S.C.; Tong, A.Y.; Talley, D.

    1983-01-01T23:59:59.000Z

    The problem of transient droplet vaporization in a hot convective environment is examined. The main objective of the present study is to develop an algorithm for the droplet vaporization which is simple enough to be feasibly incorporated into a complete spray combustion analysis and yet will also account for the important physics such as liquid-phase internal circulation, unsteady droplet heating and axisymmetric gas-phase convection. A simplified liquid-phase model has been obtained based on the assumption of the existence of a Hill's spherical vortex inside the droplet together with some approximations made in the governing diffusion equation. The use of the simplified model in a spray situation has also been examined. It has been found that droplet heating and vaporization are essentially unsteady and droplet temperature is nonuniform for a significant portion of its lifetime. It has also been found that the droplet vaporization characteristic can be quite sensitive to the particular liquid-phase and gas-phase models. The results of the various models are compared with the existing experimental data. Due to large scattering in the experimental measurements, particularly the droplet diameter, no definite conclusion can be drawn based on the experimental data. Finally, certain research problems which are related to the present study are suggested for future studies.

  20. Chemical vapor deposition of mullite coatings

    DOE Patents [OSTI]

    Sarin, Vinod (Lexington, MA); Mulpuri, Rao (Boston, MA)

    1998-01-01T23:59:59.000Z

    This invention is directed to the creation of crystalline mullite coatings having uniform microstructure by chemical vapor deposition (CVD). The process comprises the steps of establishing a flow of reactants which will yield mullite in a CVD reactor, and depositing a crystalline coating from the reactant flow. The process will yield crystalline coatings which are dense and of uniform thickness.

  1. Program performs vapor-liquid equilibrium calculations

    SciTech Connect (OSTI)

    Rice, V.L.

    1982-06-28T23:59:59.000Z

    A program designed for the Hewlett-Packard HP-41CV or 41C calculators solves basic vapor-liquid equilibrium problems, including figuring the dewpoint, bubblepoint, and equilibrium flash. The algorithm uses W.C. Edmister's method for predicting ideal-solution K values.

  2. Effects of capillarity and vapor adsorption in the depletion of vapor-dominated geothermal reservoirs

    SciTech Connect (OSTI)

    Pruess, Karsten; O'Sullivan, Michael

    1992-01-01T23:59:59.000Z

    Vapor-dominated geothermal reservoirs in natural (undisturbed) conditions contain water as both vapor and liquid phases. The most compelling evidence for the presence of distributed liquid water is the observation that vapor pressures in these systems are close to saturated vapor pressure for measured reservoir temperatures (White et al., 1971; Truesdell and White, 1973). Analysis of natural heat flow conditions provides additional, indirect evidence for the ubiquitous presence of liquid. From an analysis of the heat pipe process (vapor-liquid counterflow) Preuss (1985) inferred that effective vertical permeability to liquid phase in vapor-dominated reservoirs is approximately 10{sup 17} m{sup 2}, for a heat flux of 1 W/m{sup 2}. This value appears to be at the high end of matrix permeabilities of unfractured rocks at The Geysers, suggesting that at least the smaller fractures contribute to liquid permeability. For liquid to be mobile in fractures, the rock matrix must be essentially completely liquid-saturated, because otherwise liquid phase would be sucked from the fractures into the matrix by capillary force. Large water saturation in the matrix, well above the irreducible saturation of perhaps 30%, has been shown to be compatible with production of superheated steam (Pruess and Narasimhan, 1982). In response to fluid production the liquid phase will boil, with heat of vaporization supplied by the reservoir rocks. As reservoir temperatures decline reservoir pressures will decline also. For depletion of ''bulk'' liquid, the pressure would decline along the saturated vapor pressure curve, while for liquid held by capillary and adsorptive forces inside porous media, an additional decline will arise from ''vapor pressure lowering''. Capillary pressure and vapor adsorption effects, and associated vapor pressure lowering phenomena, have received considerable attention in the geothermal literature, and also in studies related to geologic disposal of heat generating nuclear wastes, and in the drying of porous materials. Geothermally oriented studies were presented by Chicoine et al. (1977), Hsieh and Ramey (1978, 1981), Herkelrath et al. (1983), and Nghiem and Ramey (1991). Nuclear waste-related work includes papers by Herkelrath and O'Neal (1985), Pollock (1986), Eaton and Bixler (1987), Pruess et al. (1990), Nitao (1990), and Doughty and E'ruess (1991). Applications to industrial drying of porous materials have been discussed by Hamiathy (1969) arid Whitaker (1977). This paper is primarily concerned with evaluating the impact of vapor pressure lowering (VPL) effects on the depletion behavior of vapor-dominated reservoirs. We have examined experimental data on vapor adsorption and capillary pressures in an effort to identify constitutive relationships that would be applicable to the tight matrix rocks of vapor-dominated systems. Numerical simulations have been performed to evaluate the impact of these effects on the depletion of vapor-dominated reservoirs.

  3. Axion Dark Matter Detection using Atomic Transitions

    E-Print Network [OSTI]

    P. Sikivie

    2014-09-09T23:59:59.000Z

    Dark matter axions may cause transitions between atomic states that differ in energy by an amount equal to the axion mass. Such energy differences are conveniently tuned using the Zeeman effect. It is proposed to search for dark matter axions by cooling a kilogram-sized sample to milliKelvin temperatures and count axion induced transitions using laser techniques. This appears an appropriate approach to axion dark matter detection in the $10^{-4}$ eV mass range.

  4. Modeling engine oil vaporization and transport of the oil vapor in the piston ring pack on internal combustion engines

    E-Print Network [OSTI]

    Cho, Yeunwoo, 1973-

    2004-01-01T23:59:59.000Z

    A model was developed to study engine oil vaporization and oil vapor transport in the piston ring pack of internal combustion engines. With the assumption that the multi-grade oil can be modeled as a compound of several ...

  5. Electromagnetically induced transparency with broadband laser pulses D. D. Yavuz

    E-Print Network [OSTI]

    Yavuz, Deniz

    Electromagnetically induced transparency with broadband laser pulses D. D. Yavuz Department pulses inside an atomic medium using electromag- netically induced transparency. Extending the suggestion.65. k Over the last decade, counterintuitive optical effects using electromagnetically induced

  6. Laser Desorption of Large Molecules: Mechanisms and Models

    E-Print Network [OSTI]

    Vertes, Akos

    sought intensively. Medium (keV) and high (MeV) energy ions or atoms impinging on a solid surface turned of the scope of investigations. This was especially true in mass spectrometry, where the separation as a possible way to promote vaporization over decomposition [1,2]. Pyrolysis mass spectrometry was the first

  7. Biocavity Lasers

    SciTech Connect (OSTI)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05T23:59:59.000Z

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  8. Laser ignition

    DOE Patents [OSTI]

    Early, James W. (Los Alamos, NM); Lester, Charles S. (San Juan Pueblo, NM)

    2002-01-01T23:59:59.000Z

    In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.

  9. Atomic structure, electrical properties, and infrared range optical properties of diamondlike carbon films containing

    E-Print Network [OSTI]

    Wei, Qiuming

    , and elastic modulus.4 Furthermore, unlike polycrystalline diamond films pre- pared by chemical vapor, infrared (IR) transparent, and chemically inert.3 High-quality DLC films can rival diamond films in terms- tigations have confirmed that ultraviolet (UV) pulsed laser ablation of a high-purity polycrystalline

  10. Characterization of a Tunable Optical Parametric Oscillator Laser System for Multielement Flame

    E-Print Network [OSTI]

    Michel, Robert G.

    spectrum to allow for the determination of as many elements as possible, together with high peak energy to enable the atomic energy levels to be optically saturated by the laser, and high average power to allow Laser Excited Atomic Fluorescence Spectrometry of Cobalt, Copper, Lead, Manganese, and Thallium

  11. Industrial Heat Pumps Using Solid/Vapor Working Fluids

    E-Print Network [OSTI]

    Rockenfeller, U.

    with vapor re-compression recovery systems. The state-of-the-art heat pump equipment employing liquid/vapor working fluids fulfills the requirements only in some applications. The employment of solid/vapor complex compounds leads to 'nore cost effective... allows for firing temperatures much higher than possible with liquid/vapor systems. The high energy density per unit mass and the independence of the vapor pressure from the refrigerant concentration (p = f (T), p "# f( x)) over a wide range leads...

  12. Investigation of anti-Relaxation coatings for alkali-metal vapor cells using surface science techniques

    SciTech Connect (OSTI)

    Seltzer, S. J.; Michalak, D. J.; Donaldson, M. H.; Balabas, M. V.; Barber, S. K.; Bernasek, S. L.; Bouchiat, M.-A.; Hexemer, A.; Hibberd, A. M.; Jackson Kimball, D. F.; Jaye, C.; Karaulanov, T.; Narducci, F. A.; Rangwala, S. A.; Robinson, H. G.; Shmakov, A. K.; Voronov, D. L.; Yashchuk, V. V.; Pines, A.; Budker, D.

    2010-10-11T23:59:59.000Z

    Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10?000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of C=C double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials.

  13. Coherent flash of light emitted by a cold atomic cloud

    SciTech Connect (OSTI)

    Chalony, M. [Institut Non Lineaire de Nice, Universite de Nice Sophia-Antipolis, CNRS, F-06560 Valbonne (France); Pierrat, R. [Institut Langevin, ESPCI ParisTech, CNRS UMR 7587, 10 rue Vauquelin, F-75005 Paris (France); Delande, D. [Laboratoire Kastler Brossel, UPMC-Paris 6, ENS, CNRS, 4 Place Jussieu, F-75005 Paris (France); Wilkowski, D. [Institut Non Lineaire de Nice, Universite de Nice Sophia-Antipolis, CNRS, F-06560 Valbonne (France); Centre for Quantum Technologies, National University of Singapore, 117543 Singapore (Singapore)

    2011-07-15T23:59:59.000Z

    When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the atomic scatterers. We analyze quantitatively its temporal properties and show very good agreement with theoretical predictions. Based on complementary experiments, the phase of the coherent field is reconstructed without interferometric tools.

  14. Laser program annual report, 1979

    SciTech Connect (OSTI)

    Coleman, L.W.; Strack, J.R. (eds.)

    1980-03-01T23:59:59.000Z

    This volume contains four sections that covers the areas of target design, target fabrication, diagnostics, and experiments. Section 3 reports on target design activities, plasma theory and simulation, code development, and atomic theory. Section 4 presents the accomplishments of the target fabrication group, and Section 5 presents results of diagnostic developments and applications for the year. The results of laser-target experiments are presented. (MOW)

  15. Evaluation of tropospheric water vapor profiling using eye-safe, infrared differential absorption lidar

    SciTech Connect (OSTI)

    Rye, B.J. [Colorado Univ., Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences]|[National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Technology Lab.; Machol, J.L.; Grund, C.J.; Hardesty, R.M. [National Oceanic and Atmospheric Administration, Boulder, CO (United States). Environmental Technology Lab.

    1996-05-14T23:59:59.000Z

    Continuous, high quality profiles of water vapor, free of systematic bias, and of moderate temporal and spatial resolution are fundamental to the success of the ARM CART program. In addition, these should be acquired over long periods at low operational and maintenance cost. The development and verification of realistic climate model parameterizations for clouds and net radiation balance, and the correction of other CART site sensor observations for interferences due to the presence of water vapor are critically dependent on water vapor profile measurements. To date, application of profiles have been limited by vertical resolution and uniqueness and high operating cost, or diminished daytime performance, lack of eye-safety, and high maintenance cost. Recent developments in infrared laser and detector technology make possible compact IR differential absorption lidar (DIAL) systems at eye-safe wavelengths. In the studies reported here, we develop DIAL system performance models and examine the potential of solving some of the shortcomings of previous methods using parameters representative of current technologies. These simulations are also applied to determine the strengths and weaknesses unique to the DIAL method for this application.

  16. ccsd-00000648(version1):29Sep2003 Damping rates of the atomic velocity in Sisyphus cooling

    E-Print Network [OSTI]

    an impressive progress in laser cooling techniques, and nowdays it is possible to prepare and manipulate veryccsd-00000648(version1):29Sep2003 Damping rates of the atomic velocity in Sisyphus cooling Laurent of the damping process of the atomic velocity in Sisyphus cooling. The relaxation rates of the atomic kinetic

  17. A high-pressure atomic force microscope for imaging in supercritical...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of fluid density fluctuations that change the fluid refractive index and hence the laser path. We demonstrate with our apparatus in-situ atomic scale imaging of a calcite...

  18. Bose-Einstein condensation in atomic hydrogen T. J. Greytak 1

    E-Print Network [OSTI]

    a remote chance of obtaining Bose-Einstein condensation. Using a quantum theory of corresponding states cooling of atoms allowed the alkali vapors to be pre-cooled to temperatures low enough that evaporative cooling could be used to take them into the sub-µK realm. Since 1995, many fruitful experiments have been

  19. Microfabricated alkali vapor cell with anti-relaxation wall coating

    SciTech Connect (OSTI)

    Straessle, R.; Pétremand, Y.; Briand, D.; Rooij, N. F. de, E-mail: nico.derooij@epfl.ch [Institute of Microengineering (IMT), Sensors, Actuators and Microsystems Laboratory (SAMLAB), Ecole Polytechnique Fédérale de Lausanne EPFL, 2000 Neuchâtel (Switzerland); Pellaton, M.; Affolderbach, C.; Mileti, G., E-mail: gaetano.mileti@unine.ch [Laboratoire Temps-Fréquence (LTF), Institut de Physique, Université de Neuchâtel, 2000 Neuchâtel (Switzerland)

    2014-07-28T23:59:59.000Z

    We present a microfabricated alkali vapor cell equipped with an anti-relaxation wall coating. The anti-relaxation coating used is octadecyltrichlorosilane and the cell was sealed by thin-film indium-bonding at a low temperature of 140?°C. The cell body is made of silicon and Pyrex and features a double-chamber design. Depolarizing properties due to liquid Rb droplets are avoided by confining the Rb droplets to one chamber only. Optical and microwave spectroscopy performed on this wall-coated cell are used to evaluate the cell's relaxation properties and a potential gas contamination. Double-resonance signals obtained from the cell show an intrinsic linewidth that is significantly lower than the linewidth that would be expected in case the cell had no wall coating but only contained a buffer-gas contamination on the level measured by optical spectroscopy. Combined with further experimental evidence this proves the presence of a working anti-relaxation wall coating in the cell. Such cells are of interest for applications in miniature atomic clocks, magnetometers, and other quantum sensors.

  20. Growth of graphene underlayers by chemical vapor deposition

    SciTech Connect (OSTI)

    Fabiane, Mopeli; Khamlich, Saleh; Bello, Abdulhakeem; Dangbegnon, Julien; Momodu, Damilola; Manyala, Ncholu, E-mail: ncholu.manyala@up.ac.za [Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa)] [Department of Physics, Institute of Applied Materials, SARChI Chair in Carbon Technology and Materials, University of Pretoria, Pretoria 0028 (South Africa); Charlie Johnson, A. T. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)] [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

    2013-11-15T23:59:59.000Z

    We present a simple and very convincing approach to visualizing that subsequent layers of graphene grow between the existing monolayer graphene and the copper catalyst in chemical vapor deposition (CVD). Graphene samples were grown by CVD and then transferred onto glass substrates by the bubbling method in two ways, either direct-transfer (DT) to yield poly (methyl methacrylate) (PMMA)/graphene/glass or (2) inverted transfer (IT) to yield graphene/PMMA/glass. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to reveal surface features for both the DT and IT samples. The results from FE-SEM and AFM topographic analyses of the surfaces revealed the underlayer growth of subsequent layers. The subsequent layers in the IT samples are visualized as 3D structures, where the smaller graphene layers lie above the larger layers stacked in a concentric manner. The results support the formation of the so-called “inverted wedding cake” stacking in multilayer graphene growth.

  1. Aerosol chemical vapor deposition of metal oxide films

    DOE Patents [OSTI]

    Ott, Kevin C. (4745 Trinity Dr., Los Alamos, NM 87544); Kodas, Toivo T. (5200 Noreen Dr. NE., Albuquerque, NM 87111)

    1994-01-01T23:59:59.000Z

    A process of preparing a film of a multicomponent metal oxide including: forming an aerosol from a solution comprised of a suitable solvent and at least two precursor compounds capable of volatilizing at temperatures lower than the decomposition temperature of said precursor compounds; passing said aerosol in combination with a suitable oxygen-containing carrier gas into a heated zone, said heated zone having a temperature sufficient to evaporate the solvent and volatilize said precursor compounds; and passing said volatilized precursor compounds against the surface of a substrate, said substrate having a sufficient temperature to decompose said volatilized precursor compounds whereby metal atoms contained within said volatilized precursor compounds are deposited as a metal oxide film upon the substrate is disclosed. In addition, a coated article comprising a multicomponent metal oxide film conforming to the surface of a substrate selected from the group consisting of silicon, magnesium oxide, yttrium-stabilized zirconium oxide, sapphire, or lanthanum gallate, said multicomponent metal oxide film characterized as having a substantially uniform thickness upon said FIELD OF THE INVENTION The present invention relates to the field of film coating deposition techniques, and more particularly to the deposition of multicomponent metal oxide films by aerosol chemical vapor deposition. This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  2. Atomizing nozzle and process

    DOE Patents [OSTI]

    Anderson, I.E.; Figliola, R.S.; Molnar, H.M.

    1993-07-20T23:59:59.000Z

    High pressure atomizing nozzle includes a high pressure gas manifold having a divergent expansion chamber between a gas inlet and arcuate manifold segment to minimize standing shock wave patterns in the manifold and thereby improve filling of the manifold with high pressure gas for improved melt atomization. The atomizing nozzle is especially useful in atomizing rare earth-transition metal alloys to form fine powder particles wherein a majority of the powder particles exhibit particle sizes having near-optimum magnetic properties.

  3. Apparatus and method for photochemical vapor deposition

    DOE Patents [OSTI]

    Jackson, Scott C. (Wilmington, DE); Rocheleau, Richard E. (Wilmington, DE)

    1987-03-31T23:59:59.000Z

    A photochemical vapor deposition apparatus includes a reactor housing having a window in one wall above a reaction chamber in the housing. A transparent curtain divides the reaction chamber into a reaction zone and a flush zone. At least one substrate is mounted in the reaction zone in light communication with the window so that ultraviolet radiation may penetrate through the window into the reaction zone. The window is kept clear by a gas flowing through the flush zone.

  4. Solid-Vapor Sorption Refrigeration Systems

    E-Print Network [OSTI]

    Graebel, W.; Rockenfeller, U.; Kirol, L.

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract... Complex compound sorption reactions are ideally suited for use in refrigeration cycles as an economically viable alternative to CFC refrigerants. Complex compound refrigeration provides a number of energy-saving advantages over present refrigeration...

  5. DuPont Chemical Vapor Technical Report

    SciTech Connect (OSTI)

    MOORE, T.L.

    2003-10-03T23:59:59.000Z

    DuPont Safety Resources was tasked with reviewing the current chemical vapor control practices and providing preventive recommendations on best commercial techniques to control worker exposures. The increased focus of the tank closure project to meet the 2024 Tri-Party Agreement (TPA) milestones has surfaced concerns among some CH2MHill employees and other interested parties. CH2MHill is committed to providing a safe working environment for employees and desires to safely manage the tank farm operations using appropriate control measures. To address worker concerns, CH2MHill has chartered a ''Chemical Vapors Project'' to integrate the activities of multiple CH2MHill project teams, and solicit the expertise of external resources, including an independent Industrial Hygiene expert panel, a communications consultant, and DuPont Safety Resources. Over a three-month time period, DuPont worked with CH2MHill ESH&Q, Industrial Hygiene, Engineering, and the independent expert panel to perform the assessment. The process included overview presentations, formal interviews, informal discussions, documentation review, and literature review. DuPont Safety Resources concluded that it is highly unlikely that workers in the tank farms are exposed to chemicals above established standards. Additionally, the conventional and radiological chemistry is understood, the inherent chemical hazards are known, and the risk associated with chemical vapor exposure is properly managed. The assessment highlighted management's commitment to addressing chemical vapor hazards and controlling the associated risks. Additionally, we found the Industrial Hygiene staff to be technically competent and well motivated. The tank characterization data resides in a comprehensive database containing the tank chemical compositions and relevant airborne concentrations.

  6. Vapor-phase heat-transport system

    SciTech Connect (OSTI)

    Hedstrom, J.C.

    1983-01-01T23:59:59.000Z

    A vapor-phase heat-transport system is being tested in one of the passive test cells at Los Alamos. The system consists of one selective-surface collector and a condenser inside a water storage tank. The refrigerant, R-11, can be returned to the collector by gravity or with a pump. Results from several operating configurations are presented, together with a comparison with other passive systems. A new self-pumping concept is presented.

  7. Combined rankine and vapor compression cycles

    DOE Patents [OSTI]

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19T23:59:59.000Z

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  8. High volume fuel vapor release valve

    SciTech Connect (OSTI)

    Gimby, D.R.

    1991-09-03T23:59:59.000Z

    This patent describes a fuel vapor release valve for use in a vehicle fuel system. It comprises a valve housing 10 placed in a specific longitudinal orientation, the valve housing 10 defining an interior cavity 22 having an inlet 20 for admitting fuel vapor and an outlet 14 for discharging such fuel vapor; a valve member 24 positioned in the cavity 22 for movement between an outlet 14 opening position and an outlet 14 closing position, the valve member 24 including a cap member 34 having a seat surface 36 for mating with the outlet 14 and an orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 extending through the cap member 34 providing a passageway from the outlet 14 to the cavity 22, the orifice 42 having a lesser radius than the outlet 14; the valve member 24 further including a plug member 30 engaged with the cap member 34 for movement between an orifice 42 opening position and an orifice 42 closing position; and, a valve housing tilt responsive means for moving the valve member 24 to an outlet 14 and orifice 42 closing position in response to tilting of the valve 10 about its longitudinal axis whereby, upon the return of the valve 10 to its specified longitudinal orientation, the plug member 30 first moves to an orifice 42 opening position and the cap member 34 subsequently moves to an outlet 14 opening position.

  9. Light storage via coherent population oscillation in a thermal cesium vapor

    E-Print Network [OSTI]

    A. J. F. de Almeida; J. Sales; M. -A. Maynard; T. Laupretre; F. Bretenaker; D. Felinto; F. Goldfarb; J. W. R. Tabosa

    2014-09-19T23:59:59.000Z

    We report on the storage of light via the phenomenon of Coherent Population Oscillation (CPO) in an atomic cesium vapor at room temperature. In the experiment the optical information of a probe field is stored in the CPO of two ground states of a Lambda three-level system formed by the Zeeman sublevels of the hyperfine transition F = 3 - F' = 2 of cesium D2 line. We show directly that this CPO based memory is very insensitive to stray magnetic field inhomogeneities and presents a lifetime which is mainly limited only by atomic motion. A theoretical simulation of the measured spectra was also developed and is in very good agreement with the experiment.

  10. Drop shaping by laser-pulse impact

    E-Print Network [OSTI]

    Klein, Alexander L; Visser, Claas Willem; Lhuissier, Henri; Sun, Chao; Snoeijer, Jacco H; Villermaux, Emmanuel; Lohse, Detlef; Gelderblom, Hanneke

    2015-01-01T23:59:59.000Z

    We study the hydrodynamic response of a falling drop hit by a laser pulse. Combining high-speed with stroboscopic imaging we report that a millimeter-sized dyed water drop hit by a milli-Joule nanosecond laser-pulse deforms and propels forward at several meters per second, until it eventually fragments. We show that the drop motion results from the recoil momentum imparted at the drop surface by water vaporization. We measure the propulsion speed and the time-deformation law of the drop, complemented by boundary integral simulations. We explain the drop propulsion and shaping in terms of the laser pulse energy and drop surface tension. These findings are crucial for the generation of extreme ultraviolet (EUV) light in lithography machines.

  11. Laser assisted arc welding for aluminum alloys

    SciTech Connect (OSTI)

    Fuerschbach, P.W.

    2000-01-01T23:59:59.000Z

    Experiments have been performed using a coaxial end-effector to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (<1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  12. Title of Document: INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE

    E-Print Network [OSTI]

    Anlage, Steven

    ABSTRACT Title of Document: INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE-cluster interaction. #12;INTERACTION OF INTENSE SHORT LASER PULSES WITH GASES OF NANOSCALE ATOMIC AND MOLECULAR., Department of Electrical and Computer Engineering We study the interaction of intense laser pulses with gases

  13. Multiply Charged Thorium Crystals for Nuclear Laser Spectroscopy

    SciTech Connect (OSTI)

    Campbell, C. J.; Steele, A. V.; Churchill, L. R.; DePalatis, M. V.; Naylor, D. E.; Kuzmich, A.; Chapman, M. S. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States); Matsukevich, D. N. [School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332-0430 (United States); Department of Physics and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742 (United States)

    2009-06-12T23:59:59.000Z

    We have produced laser-cooled crystals of {sup 232}Th{sup 3+} in a linear rf Paul trap. This is the first time that a multiply charged ion has been laser cooled. Our work opens an avenue for excitation of the nuclear transition in a trapped, cold {sup 229}Th{sup 3+} ion. Laser excitation of nuclear states would establish a new bridge between atomic and nuclear physics, with the promise of new levels of metrological precision.

  14. Analogy between free electron laser and channeling by crystal planes

    E-Print Network [OSTI]

    X. Artru

    2005-03-21T23:59:59.000Z

    The trapping of electrons in the ponderomotive potential wells, which governs a free electron laser or inverse free electron laser at high gain, is analogous to the channeling of charged particles by atomic planes of a crystal. A bent crystal is analogous to a period-tapered free electron laser. This analogy is different from the well-known one between channeling and undulator radiations.

  15. Exploding conducting film laser pumping apparatus

    DOE Patents [OSTI]

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

    1986-01-01T23:59:59.000Z

    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.

  16. Atomic swelling upon compression

    E-Print Network [OSTI]

    V. K. Dolmatov; J. L. King

    2012-08-18T23:59:59.000Z

    The hydrogen atom under the pressure of a spherical penetrable confinement potential of a decreasing radius $r_{0}$ is explored, as a case study. A novel counter-intuitive effect of atomic swelling rather than shrinking with decreasing $r_{0}$ is unraveled, when $r_{0}$ reaches, and remains smaller than, a certain critical value. Upon swelling, the size of the atom is shown to increase by an order of magnitude, or more, compared to the size of the free atom. Examples of changes of photoabsorption properties of confined hydrogen atom upon its swelling are uncovered and demonstrated.

  17. Laser goniometer

    DOE Patents [OSTI]

    Fairer, George M. (Boulder, CO); Boernge, James M. (Lakewood, CO); Harris, David W. (Lakewood, CO); Campbell, DeWayne A. (Littleton, CO); Tuttle, Gene E. (Littleton, CO); McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO)

    1993-01-01T23:59:59.000Z

    The laser goniometer is an apparatus which permits an operator to sight along a geologic feature and orient a collimated lamer beam to match the attitude of the feature directly. The horizontal orientation (strike) and the angle from horizontal (dip), are detected by rotary incremental encoders attached to the laser goniometer which provide a digital readout of the azimuth and tilt of the collimated laser beam. A microprocessor then translates the square wave signal encoder outputs into an ASCII signal for use by data recording equipment.

  18. Vacuum squeezing via polarization self-rotation and excess noise in hot Rb vapors

    E-Print Network [OSTI]

    Eugeniy E. Mikhailov; Arturo Lezama; Thomas W. Noel; Irina Novikova

    2009-03-18T23:59:59.000Z

    We present experimental and theoretical analysis of quantum fluctuation in a vacuum field in the presence of orthogonal linearly polarized pump field propagating through a Rb vapor cell. Previously reported theoretical and experimental studies provided somewhat contradictory conclusions regarding the possibility to observe the "squeezed vacuum" -- the reduction of vacuum fluctuations below standard quantum limit -- in this system. Here, using the D1 transitions of Rb in a cell without buffer as as an example, we demonstrate that vacuum squeezing is corrupted by incoherent processes (such as spontaneous emission, elastic scattering, etc.), and its observation is only possible in a specific small region of the experimental parameter space. Numerical simulations, in good agreement with the experiment, demonstrate that the two excited state hyperfine levels play a crucial role in the squeezing and excess noise production. The significant influence of far-detuned atoms on the field fluctuations at low noise frequencies imposes the explicit consideration of the full velocity distribution of the atomic vapor.

  19. Laser Optomechanics

    E-Print Network [OSTI]

    Yang, Weijian; Ng, Kar Wei; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J

    2015-01-01T23:59:59.000Z

    Cavity optomechanics explores the coupling between the optical field and the mechanical oscillation to induce cooling and regenerative oscillation in a mechanical oscillator. So far, optomechanics relies on the detuning between the cavity and an external pump laser, where the laser acts only as a power supply. Here, we report a new scheme with mutual coupling between a mechanical oscillator that supports a mirror of a vertical-cavity surface-emitting laser (VCSEL) and the optical field, greatly enhancing the light-matter energy transfer. In this work, we used an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror in a VCSEL, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity with > 550 nm self-oscillation amplitude of the micro-mechanical oscillator, two to three orders of magnitude larger than typical. This new scheme not only offers an efficient approach for high-...

  20. Laser barometer

    SciTech Connect (OSTI)

    Abercrombie, K.R.; Shiels, D.; Rash, T.

    1998-04-01T23:59:59.000Z

    This paper describes an invention of a pressure measuring instrument which uses laser radiation to sense the pressure in an enclosed environment by means of measuring the change in refractive index of a gas - which is pressure dependent.

  1. Method and apparatus for concentrating vapors for analysis

    DOE Patents [OSTI]

    Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

    2012-06-05T23:59:59.000Z

    A pre-concentration device and a method are disclosed for concentrating gaseous vapors for analysis. Vapors sorbed and concentrated within the bed of the pre-concentration device are thermally desorbed, achieving at least partial separation of the vapor mixtures. The pre-concentration device is suitable, e.g., for pre-concentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable.

  2. G-Band Vapor Radiometer Profiler (GVRP) Handbook

    SciTech Connect (OSTI)

    Caddeau, MP

    2010-06-23T23:59:59.000Z

    The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

  3. Design of a dual species atom interferometer for space

    E-Print Network [OSTI]

    Schuldt, Thilo; Krutzik, Markus; Bote, Lluis Gesa; Gaaloul, Naceur; Hartwig, Jonas; Ahlers, Holger; Herr, Waldemar; Posso-Trujillo, Katerine; Rudolph, Jan; Seidel, Stephan; Wendrich, Thijs; Ertmer, Wolfgang; Herrmann, Sven; Kubelka-Lange, André; Milke, Alexander; Rievers, Benny; Rocco, Emanuele; Hinton, Andrew; Bongs, Kai; Oswald, Markus; Franz, Matthias; Hauth, Matthias; Peters, Achim; Bawamia, Ahmad; Wicht, Andreas; Battelier, Baptiste; Bertoldi, Andrea; Bouyer, Philippe; Landragin, Arnaud; Massonnet, Didier; Lévèque, Thomas; Wenzlawski, Andre; Hellmig, Ortwin; Windpassinger, Patrick; Sengstock, Klaus; von Klitzing, Wolf; Chaloner, Chris; Summers, David; Ireland, Philip; Mateos, Ignacio; Sopuerta, Carlos F; Sorrentino, Fiodor; Tino, Guglielmo M; Williams, Michael; Trenkel, Christian; Gerardi, Domenico; Chwalla, Michael; Burkhardt, Johannes; Johann, Ulrich; Heske, Astrid; Wille, Eric; Gehler, Martin; Cacciapuoti, Luigi; Gürlebeck, Norman; Braxmaier, Claus; Rasel, Ernst

    2014-01-01T23:59:59.000Z

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species $^{85}$Rb/$^{87}$Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry...

  4. Investigation of polarization spectroscopy for detecting atomic hydrogen in flames

    E-Print Network [OSTI]

    Kulatilaka, Waruna Dasal

    2002-01-01T23:59:59.000Z

    . The probe beam was tuned to the single-photon 486-nm n = 2 --> n = 4 resonance of the hydrogen atom by fundamental and frequency-doubled beams from a single 486-nm dye laser were used. The probe beam was linearly polarized entering the flame...

  5. Method for controlling corrosion in thermal vapor injection gases

    DOE Patents [OSTI]

    Sperry, John S. (Houston, TX); Krajicek, Richard W. (Houston, TX)

    1981-01-01T23:59:59.000Z

    An improvement in the method for producing high pressure thermal vapor streams from combustion gases for injection into subterranean oil producing formations to stimulate the production of viscous minerals is described. The improvement involves controlling corrosion in such thermal vapor gases by injecting water near the flame in the combustion zone and injecting ammonia into a vapor producing vessel to contact the combustion gases exiting the combustion chamber.

  6. Heat Recovery in Distillation by Mechanical Vapor Recompression

    E-Print Network [OSTI]

    Becker, F. E.; Zakak, A. I.

    tower energy requirements can be achieved by mechanical vapor recompression. Three design approaches for heating a distillation tower reboiler by mechanical vapor recompression are presented. The advantages of using a screw compressor are discussed... for lowering energy consumption in the distillation process through various heat recovery techniques. (3-8) One such technique utilizes mechanical vapor recompression. (9-12) The principle of this ap proach involves the use of a compressor to recycle...

  7. Recovery of benzene in an organic vapor monitor

    E-Print Network [OSTI]

    Krenek, Gregory Joel

    1980-01-01T23:59:59.000Z

    solid adsorbents available (silica gel, activated alumina, etc. ), activated charcoal is most frequently utilized. Activated charcoal has retentivity for sorbed vapors several times that of silica gel and it displays a selectivity for organic vapors... (diffusion rate) of the vapor molecules to the sur- face of the adsorbent. The adsorption process determine how effective the adsorbent collects and holds the contam- inant on the surface of the activated charcoal. Recovery of the contaminant from...

  8. Review of enhanced vapor diffusion in porous media

    SciTech Connect (OSTI)

    Webb, S.W.; Ho, C.K.

    1998-08-01T23:59:59.000Z

    Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper.

  9. Advanced Chemical Heat Pumps Using Liquid-Vapor Reactions

    E-Print Network [OSTI]

    Kirol, L.

    ADVANCED CHEMICAL HEAT PUMPS USING LIQUID-VAPOR REACTIONS LANCE KIROL Senior Program Specialist Idaho National Engineering Laboratory Idaho Falls, Idaho . ABSTRACT Chemical heat pumps utilizing liquid-vapor reactions can be configured... in forms analogous to electric drive vapor-compression heat pumps and heat activated absorption heat pumps. Basic thermodynamic considerations eliminate some heat pumps and place restrictive working fluid requirements on others, but two thermodynam...

  10. New Combined Laser Ablation Platform Determines Cell Wall Chemistry (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-09-01T23:59:59.000Z

    NREL has designed and developed a combined laser ablation/pulsed sample introduction/mass spectrometry platform that integrates pyrolysis and/or laser ablation with resonance-enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry. Using this apparatus, we can measure the cell wall chemical composition of untreated biomass materials. Understanding the chemical composition of untreated biomass is key to both the biochemical and thermochemical conversion of lignocellulosic biomass to biofuels. In the biochemical conversion process, the new technique provides a better understanding of the chemistry of lignin and will improve accessibility to plant sugars. In thermochemical conversion, the information provided by the new technique may help to reduce the formation of unwanted byproducts during gasification. NREL validated the ability of the system to detect pyrolysis products from plant materials using poplar, a potentially high-impact bioenergy feedstock. In the technique, biomass vapors are produced by laser ablation using the 3rd harmonic of an Nd:YAG laser (355 nm). The resulting vapors are entrained in a free jet expansion of helium, then skimmed and introduced into an ionization region. REMPI is used to ionize the vapors because it is highly sensitive for detecting lignin and aromatic metabolites. The laser ablation method was used to selectively volatilize specific plant tissues and detect lignin-based products from the vapors with enhanced sensitivity. This will allow the determination of lignin distribution in future biomass studies.

  11. ccsd00000648 Damping rates of the atomic velocity in Sisyphus cooling

    E-Print Network [OSTI]

    decades have witnessed an impressive progress in laser cooling techniques, and nowdays it is possibleccsd­00000648 (version 1) : 29 Sep 2003 Damping rates of the atomic velocity in Sisyphus cooling and experimental study of the damping process of the atomic velocity in Sisyphus cooling. The relaxation rates

  12. Modelling a ratchet with cold atoms in an optical lattice C. Robilliard

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modelling a ratchet with cold atoms in an optical lattice C. Robilliard , D. Lucas , and G of a model ratchet consisting of laser- cooled rubidium atoms localized in an asymmetric periodic potential of ratchets has been increasingly studied in recent years [1]. From a general point of view, a ratchet

  13. Probabilistic quantum gates between remote atoms through interference of optical frequency qubits

    E-Print Network [OSTI]

    Madsen, Martin John

    Probabilistic quantum gates between remote atoms through interference of optical frequency qubits L gates on remote trapped atom qubits through interference of optical frequency qubits. The method does be localized well under the Lamb-Dicke limit through laser cooling in a strong trap, the elimination

  14. Vapor port and groundwater sampling well

    DOE Patents [OSTI]

    Hubbell, J.M.; Wylie, A.H.

    1996-01-09T23:59:59.000Z

    A method and apparatus have been developed for combining groundwater monitoring wells with unsaturated-zone vapor sampling ports. The apparatus allows concurrent monitoring of both the unsaturated and the saturated zone from the same well at contaminated areas. The innovative well design allows for concurrent sampling of groundwater and volatile organic compounds (VOCs) in the vadose (unsaturated) zone from a single well, saving considerable time and money. The sample tubes are banded to the outer well casing during installation of the well casing. 10 figs.

  15. Vapor port and groundwater sampling well

    DOE Patents [OSTI]

    Hubbell, Joel M. (Idaho Falls, ID); Wylie, Allan H. (Idaho Falls, ID)

    1996-01-01T23:59:59.000Z

    A method and apparatus has been developed for combining groundwater monitoring wells with unsaturated-zone vapor sampling ports. The apparatus allows concurrent monitoring of both the unsaturated and the saturated zone from the same well at contaminated areas. The innovative well design allows for concurrent sampling of groundwater and volatile organic compounds (VOCs) in the vadose (unsaturated) zone from a single well, saving considerable time and money. The sample tubes are banded to the outer well casing during installation of the well casing.

  16. Chemical vapor deposition of epitaxial silicon

    DOE Patents [OSTI]

    Berkman, Samuel (Florham Park, NJ)

    1984-01-01T23:59:59.000Z

    A single chamber continuous chemical vapor deposition (CVD) reactor is described for depositing continuously on flat substrates, for example, epitaxial layers of semiconductor materials. The single chamber reactor is formed into three separate zones by baffles or tubes carrying chemical source material and a carrier gas in one gas stream and hydrogen gas in the other stream without interaction while the wafers are heated to deposition temperature. Diffusion of the two gas streams on heated wafers effects the epitaxial deposition in the intermediate zone and the wafers are cooled in the final zone by coolant gases. A CVD reactor for batch processing is also described embodying the deposition principles of the continuous reactor.

  17. Vapor Retarder Classification - Building America Top Innovation |

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOn AprilA group current C3EDepartmentDepartment of Energy Photo of a vapor retarder

  18. Category:Mercury Vapor | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here. Category:Conceptual ModelLists forMercury Vapor page? For detailed

  19. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Montoya, Cris; Geraci, Andrew A; Eardley, Matthew; Moreland, John; Hollberg, Leo; Kitching, John

    2015-01-01T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  20. Resonant interaction of trapped cold atoms with a magnetic cantilever tip

    E-Print Network [OSTI]

    Cris Montoya; Jose Valencia; Andrew A. Geraci; Matthew Eardley; John Moreland; Leo Hollberg; John Kitching

    2015-03-26T23:59:59.000Z

    Magnetic resonance in an ensemble of laser-cooled trapped Rb atoms is excited using a micro- cantilever with a magnetic tip. The cantilever is mounted on a multi-layer chip designed to capture, cool, and magnetically transport cold atoms. The coupling is observed by measuring the loss from a magnetic trap as the oscillating cantilever induces Zeeman state transitions in the atoms. Interfacing cold atoms with mechanical devices could enable probing and manipulating atomic spins with nanometer spatial resolution and single-spin sensitivity, leading to new capabilities in quantum computation, quantum simulation, or precision sensing.

  1. acetone vapor sensing: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    XI, Universit de 7 ATMOSPHERIC WATER VAPOR PROFILES DERIVED FROM REMOTE-SENSING RADIOMETER MEASUREMENTS CiteSeer Summary: The feasibility and preliminary testing of a low...

  2. Rotary Vapor Compression Cycle Technology: A Pathway to Ultra...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Cycle Technology: A Pathway to Ultra-Efficient Air Conditioning, Heating and Refrigeration Rotary Vapor Compression Cycle Technology: A Pathway to Ultra-Efficient Air...

  3. alkali vapor species: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of hexagonal patterns in a nonlinear optical system: Alkali metal vapor in a single-mirror arrangement Physics Websites Summary: Secondary bifurcations of hexagonal patterns in...

  4. assisted chemical vapor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nanodiamonds (NDs) with 70-80 nm size via bead assisted sonic disintegration (BASD) of a polycrystalline chemical vapor deposition (CVD) film. The NDs display high crystalline...

  5. A new vapor pressure equation originating at the critical point

    E-Print Network [OSTI]

    Nuckols, James William

    1976-01-01T23:59:59.000Z

    - tence curve has been developed from critical scaling theory. The agreement between published vapor pressures and vapor pressures predicted by this equation is very good, especially in the critical region where many other vapor pressure equations fail... vapor pressure data f' or Ar, N2, 02H6, and H20, w1th the parameters ai to a being determined by an unweighted least squares curve 5 fit. The method of least squares has been described adequately elsewhere, e. g. Wylie (1966), and the theory w111...

  6. atmospheric water vapor: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    greenhouse gas, contributing to approximately two-thirds of the Earth's greenhouse effect Mitchell, 1989; IntergovernmentalA meta-analysis of water vapor...

  7. Hypothetical Thermodynamic Properties. Subcooled Vaporization Enthalpies and Vapor Pressures of Polyaromatic Hydrocarbons

    E-Print Network [OSTI]

    Chickos, James S.

    of Polyaromatic Hydrocarbons William Hanshaw, Marjorie Nutt, and James S. Chickos* Department of Chemistry and liquid vapor pressures from T ) 298.15 K to T ) 510 K of a series of polyaromatic hydrocarbons have been protocols are also made, and agreement generally is quite good. Introduction Polyaromatic hydrocarbons (PAHs

  8. M. Bahrami ENSC 461 (S 11) Vapor Power Cycles 1 Vapor Power Cycles

    E-Print Network [OSTI]

    Bahrami, Majid

    is not a suitable model for steam power cycle since: The turbine has to handle steam with low quality which will cause erosion and wear in turbine blades. It is impractical to design a compressor that handles two vapor expands isentropically in turbine and produces work. 4-1: Const P heat rejection High quality

  9. 1981 laser program annual report

    SciTech Connect (OSTI)

    Not Available

    1982-08-01T23:59:59.000Z

    This report is published in sections that correspond to the division of technical activity in the Program. Section 1 provides a Program Overview, presenting highlights of the technical accomplishments of the elements of the Program, a summary of activities carried out under the Glass Laser Experiments Lead Laboratory Program, as well as discussions of Program resources and facilities. Section 2 covers the work on solid-state Nd:glass lasers, including systems operations and Nova and Novette systems development. Section 3 reports on target-design activities, plasma theory and simulation, code development, and atomic theory. Section 4 presents the accomplishments of the Target Fabrication group, Section 5 contains the results of our diagnostics development, and Section 6 reports the results of laser-target experiments conducted during the year, along with supporting research and development activities. Section 7 presents the results from laser research and development, including solid-state R and D and the theoretical and experimental research on advanced lasers. Section 8 contains the results of studies in areas of energy and military applications, including those relating to electrical energy production by inertial-confinement fusion systems.

  10. FREE ELECTRON LASERS

    E-Print Network [OSTI]

    Colson, W.B.

    2008-01-01T23:59:59.000Z

    1984). Colson, W. B. , "Free electron laser theory," Ph.D.aspects of the free electron laser," Laser Handbook i,Quant. Elect. Bendor Free Electron Laser Conference, Journal

  11. Laser ablated hard coating for microtools

    DOE Patents [OSTI]

    McLean, W. II; Balooch, M.; Siekhaus, W.J.

    1998-05-05T23:59:59.000Z

    Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10--20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode. 12 figs.

  12. Laser ablated hard coating for microtools

    DOE Patents [OSTI]

    McLean, II, William (Oakland, CA); Balooch, Mehdi (Berkeley, CA); Siekhaus, Wigbert J. (Berkeley, CA)

    1998-05-05T23:59:59.000Z

    Wear-resistant coatings composed of laser ablated hard carbon films, are deposited by pulsed laser ablation using visible light, on instruments such as microscope tips and micro-surgical tools. Hard carbon, known as diamond-like carbon (DLC), films produced by pulsed laser ablation using visible light enhances the abrasion resistance, wear characteristics, and lifetimes of small tools or instruments, such as small, sharp silicon tips used in atomic probe microscopy without significantly affecting the sharpness or size of these devices. For example, a 10-20 nm layer of diamond-like carbon on a standard silicon atomic force microscope (AFM) tip, enables the useful operating life of the tip to be increased by at least twofold. Moreover, the low inherent friction coefficient of the DLC coating leads to higher resolution for AFM tips operating in the contact mode.

  13. Method and apparatus for precision laser micromachining

    DOE Patents [OSTI]

    Chang, Jim (San Ramon, CA); Warner, Bruce E. (Pleasanton, CA); Dragon, Ernest P. (Danville, CA)

    2000-05-02T23:59:59.000Z

    A method and apparatus for micromachining and microdrilling which results in a machined part of superior surface quality is provided. The system uses a near diffraction limited, high repetition rate, short pulse length, visible wavelength laser. The laser is combined with a high speed precision tilting mirror and suitable beam shaping optics, thus allowing a large amount of energy to be accurately positioned and scanned on the workpiece. As a result of this system, complicated, high resolution machining patterns can be achieved. A cover plate may be temporarily attached to the workpiece. Then as the workpiece material is vaporized during the machining process, the vapors condense on the cover plate rather than the surface of the workpiece. In order to eliminate cutting rate variations as the cutting direction is varied, a randomly polarized laser beam is utilized. A rotating half-wave plate is used to achieve the random polarization. In order to correctly locate the focus at the desired location within the workpiece, the position of the focus is first determined by monitoring the speckle size while varying the distance between the workpiece and the focussing optics. When the speckle size reaches a maximum, the focus is located at the first surface of the workpiece. After the location of the focus has been determined, it is repositioned to the desired location within the workpiece, thus optimizing the quality of the machined area.

  14. Improved graphite furnace atomizer

    DOE Patents [OSTI]

    Siemer, D.D.

    1983-05-18T23:59:59.000Z

    A graphite furnace atomizer for use in graphite furnace atomic absorption spectroscopy is described wherein the heating elements are affixed near the optical path and away from the point of sample deposition, so that when the sample is volatilized the spectroscopic temperature at the optical path is at least that of the volatilization temperature, whereby analyteconcomitant complex formation is advantageously reduced. The atomizer may be elongated along its axis to increase the distance between the optical path and the sample deposition point. Also, the atomizer may be elongated along the axis of the optical path, whereby its analytical sensitivity is greatly increased.

  15. Atomic Collapse Observed

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Scientists Observe Atomic Collapse State Quantum Mechanics Prediction Confirmed in Graphene Using NERSC's Hopper April 26, 2013 | Tags: Hopper, Materials Science Contact: Linda...

  16. A study of particle generation during laser ablation withapplications

    SciTech Connect (OSTI)

    Liu, Chunyi

    2005-08-12T23:59:59.000Z

    A study has been made of the generation of particles during laser ablation and has included size distribution measurements and observation of the formation processes. The particle size distribution with respect to different laser parameters was obtained in-line using a differential mobility analyzer (DMA) and a particle counter. The experimental results show that the particle size varies with laser energy, laser pulsewidth, ambient gas flow rate and sample properties. The results serve as a basis for controlling the size of nanoparticles generated by laser ablation. Laser shadowgraph imaging was used to study mass ejection processes and mechanisms. At higher laser irradiance, some particles were ejected in the liquid and even in the solid phase. Time-resolved images show the propagation of the shockwaves: external shockwaves propagate outward and decelerate, and internal shockwaves reflect back and forth between the gas contact surface and the sample surface. The internal shockwave is proposed to cause the ejection of liquid particles when the internal shockwave strikes the liquid molten layer. A simulation based on vapor plume expansion was carried out and provides satisfactory agreement with experimental results. Different material properties result in different particle ejection behavior:particle ejection for most materials including metals result in a conically shaped envelope for the ejected material while ejection for silicon resembles a liquid jet. The difference in density change when the materials melt was proposed to be an important factor in the different ejection behavior. The characteristics of particles generated by laser ablation have a strong influence on the chemical analysis of the irradiated sample. Large particles are more difficult to completely vaporize and ionize, and induced preferential vaporization causes fractionation (i.e. a detected chemical composition that differs from the sample material). Large particles also result in spikes in measurements using inductively coupled plasma mass spectrometry (ICP-MS) which result in errors. Three different methods were employed to study the effects of particle size on chemical analysis: generating smaller particles utilizing a fs laser, filtering out larger particles with a cascade impactor and altering the size distribution by using a second pulse to fracture particles generated from the first pulse. It was found that the chemical composition of the particles varies with particle size. The variation of the composition with respect to particle size was analyzed and it was proposed that it was related to the vapor formed particles condensing on larger ejected liquid droplets.

  17. The control of confined vapor phase explosions

    SciTech Connect (OSTI)

    Scilly, N.F. [Laporte plc, Widnes (United Kingdom); Owen, O.J.R. [Fine Organics, Ltd., Middlesborough (United Kingdom); Wilberforce, J.K. [Solvay SA, Brussels (Belgium)

    1995-12-31T23:59:59.000Z

    The probability of, for example, a fire or explosion occurring during a process operation is related both to the fire-related properties of the materials used, such as flash point, flammable limits etc., i.e. the material or intrinsic factors, and the nature of the operation and the equipment used, i.e. the extrinsic factors. The risk, or frequency of occurrence, of other hazards such as reaction runaway, major toxic release etc. can be determined in a similar manner. For a vapor phase explosion (and a fire) the probability of the event is the product of the probability of generating a flammable atmosphere and the probability of ignition. Firstly, materials may be coded using properties that are relevant to the hazard in question. Secondly, different operations have different degrees of risk and these risks are assigned as Low, Medium, High etc. according to criteria outlined here. Combination of these two factors will then be a measure of the overall risk of the operation with the specified material and may be used to define operating standards. Currently, the hazard/risk of a vapor phase explosions is examined by this method but in due course dust explosions, fires, condensed phase explosions, reaction runaways, physical explosions, major toxic releases and incompatibility will be included.

  18. Design of a dual species atom interferometer for space

    E-Print Network [OSTI]

    Thilo Schuldt; Christian Schubert; Markus Krutzik; Lluis Gesa Bote; Naceur Gaaloul; Jonas Hartwig; Holger Ahlers; Waldemar Herr; Katerine Posso-Trujillo; Jan Rudolph; Stephan Seidel; Thijs Wendrich; Wolfgang Ertmer; Sven Herrmann; André Kubelka-Lange; Alexander Milke; Benny Rievers; Emanuele Rocco; Andrew Hinton; Kai Bongs; Markus Oswald; Matthias Franz; Matthias Hauth; Achim Peters; Ahmad Bawamia; Andreas Wicht; Baptiste Battelier; Andrea Bertoldi; Philippe Bouyer; Arnaud Landragin; Didier Massonnet; Thomas Lévèque; Andre Wenzlawski; Ortwin Hellmig; Patrick Windpassinger; Klaus Sengstock; Wolf von Klitzing; Chris Chaloner; David Summers; Philip Ireland; Ignacio Mateos; Carlos F. Sopuerta; Fiodor Sorrentino; Guglielmo M. Tino; Michael Williams; Christian Trenkel; Domenico Gerardi; Michael Chwalla; Johannes Burkhardt; Ulrich Johann; Astrid Heske; Eric Wille; Martin Gehler; Luigi Cacciapuoti; Norman Gürlebeck; Claus Braxmaier; Ernst Rasel

    2014-12-08T23:59:59.000Z

    Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth's gravitational field, in navigation & ranging, and in fundamental physics such as tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species $^{85}$Rb/$^{87}$Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for $10^{-11}$ mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (819 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.

  19. Vapor and gas sampling of Single-Shell Tank 241-A-101 using the Vapor Sampling System

    SciTech Connect (OSTI)

    Caprio, G.S.

    1995-11-01T23:59:59.000Z

    This document presents sampling data resulting from the June 8, 1995, sampling of SST 241-A-101 using the Vapor Sampling System.

  20. Development of nanodiamond foils for H- stripping to Support the Spallation Neutron Source (SNS) using hot filament chemical vapor deposition

    SciTech Connect (OSTI)

    Vispute, R D [Blue Wave Semiconductors; Ermer, Henry K [Blue Wave Semiconductors; Sinsky, Phillip [Blue Wave Semiconductors; Seiser, Andrew [Blue Wave Semiconductors; Shaw, Robert W [ORNL; Wilson, Leslie L [ORNL

    2014-01-01T23:59:59.000Z

    Thin diamond foils are needed in many particle accelerator experiments regarding nuclear and atomic physics, as well as in some interdisciplinary research. Particularly, nanodiamond texture is attractive for this purpose as it possesses a unique combination of diamond properties such as high thermal conductivity, mechanical strength and high radiation hardness; therefore, it is a potential material for energetic ion beam stripper foils. At the ORNL Spallation Neutron Source (SNS), the installed set of foils must be able to survive a nominal five-month operation period, without the need for unscheduled costly shutdowns and repairs. Thus, a small foil about the size of a postage stamp is critical to the operation of SNS and similar sources in U.S. laboratories and around the world. We are investigating nanocrystalline, polycrystalline and their admixture films fabricated using a hot filament chemical vapor deposition (HFCVD) system for H- stripping to support the SNS at Oak Ridge National Laboratory. Here we discuss optimization of process variables such as substrate temperature, process gas ratio of H2/Ar/CH4, substrate to filament distance, filament temperature, carburization conditions, and filament geometry to achieve high purity diamond foils on patterned silicon substrates with manageable intrinsic and thermal stresses so that they can be released as free standing foils without curling. An in situ laser reflectance interferometry tool (LRI) is used for monitoring the growth characteristics of the diamond thin film materials. The optimization process has yielded free standing foils with no pinholes. The sp3/sp2 bonds are controlled to optimize electrical resistivity to reduce the possibility of surface charging of the foils. The integrated LRI and HFCVD process provides real time information on the growth of films and can quickly illustrate growth features and control film thickness. The results are discussed in the light of development of nanodiamond foils that will be able to withstand a few MW proton beam and hopefully will be able to be used after possible future upgrades to the SNS to greater than a 3MW beam.

  1. Water soluble laser dyes

    DOE Patents [OSTI]

    Hammond, Peter R. (Livermore, CA); Feeman, James F. (Wyomissing, PA); Field, George F. (Santa Ana, CA)

    1998-01-01T23:59:59.000Z

    Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

  2. Water soluble laser dyes

    DOE Patents [OSTI]

    Hammond, P.R.; Feeman, J.F.; Field, G.F.

    1998-08-11T23:59:59.000Z

    Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

  3. Optical laser systems at the Linac Coherent Light Source

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; et al

    2015-05-01T23:59:59.000Z

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  4. Phase diagram for injection locking a superradiant laser

    E-Print Network [OSTI]

    Kevin C. Cox; Joshua M. Weiner; James K. Thompson

    2014-06-19T23:59:59.000Z

    We experimentally and theoretically study the response of a superradiant or bad-cavity laser to an applied coherent drive. We observe two forms of synchronization (injection locking) between the superradiant ensemble and the applied drive: one attractive and one repulsive in nature. We explain the region of repulsion as arising from the higher three-dimensional description of the atomic spin state that stores the laser coherence in a superradiant laser, as opposed to a two-parameter description of the electric field in a traditional good-cavity laser. We derive a phase diagram of predicted behavior and experimentally measure the response of the system across various trajectories therein.

  5. Laser barometer

    DOE Patents [OSTI]

    Abercrombie, Kevin R. (Westminster, CO); Shiels, David (Thornton, CO); Rash, Tim (Aurora, CO)

    2001-02-06T23:59:59.000Z

    A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

  6. 1-Dimensional Numerical Model of Thermal Conduction and Vapor Diffusion

    E-Print Network [OSTI]

    Schörghofer, Norbert

    developed by Samar Khatiwala, 2001 extended to variable thermal properties and irregular grid by Norbert Sch for c. Upper boundary condition: a) Radiation Q + k T z z=0 = T4 z=0 Q is the incoming solar flux of Water Vapor with Phase Transitions developed by Norbert Sch¨orghofer, 2003­2004 3 phases: vapor, free

  7. Fenton Oxidation of TCE Vapors in a Foam Reactor

    E-Print Network [OSTI]

    Fenton Oxidation of TCE Vapors in a Foam Reactor Eunsung Kan,a,b Seongyup Kim,a and Marc A.interscience.wiley.com). DOI 10.1002/ep.10205 Oxidation of dilute TCE vapors in a foam reactor using Fenton's reagent composition of Fenton's reagents, the foam reactor configuration provided a higher rate absorption and greater

  8. ADHESION FORCES BETWEEN MICA SURFACES IN UNDERSATURATED VAPORS OF HYDROCARBONS

    E-Print Network [OSTI]

    Matsuoka, Hiroshige

    ADHESION FORCES BETWEEN MICA SURFACES IN UNDERSATURATED VAPORS OF HYDROCARBONS H. MATSUOKA1 , T] or meniscus force [3], which have been neglected in the conventional and relatively large mechani- cal systems forces between mica surfaces in under- saturated vapors of several kind of hydrocarbon liquids are mea

  9. Producing and Detecting Correlated atoms

    E-Print Network [OSTI]

    Christoph I. Westbrook; Martijn Schellekens; Aurélien Perrin; Valentina Krachmalnicoff; Jose Carlos Viana Gomes; Jean-Baptiste Trebbia; Jérôme Estève; Hong Chang; Isabelle Bouchoule; Denis Boiron; Alain Aspect; Tom Jeltes; John McNamara; Wim Hogervorst; Wim Vassen

    2006-09-04T23:59:59.000Z

    We discuss experiments to produce and detect atom correlations in a degenerate or nearly degenerate gas of neutral atoms. First we treat the atomic analog of the celebrated Hanbury Brown Twiss experiment, in which atom correlations result simply from interference effects without any atom interactions.We have performed this experiment for both bosons and fermions. Next we show how atom interactions produce correlated atoms using the atomic analog of spontaneous four-wavemixing. Finally, we briefly mention experiments on a one dimensional gas on an atom chip in which correlation effects due to both interference and interactions have been observed.

  10. A high-flux BEC source for mobile atom interferometers

    E-Print Network [OSTI]

    Jan Rudolph; Waldemar Herr; Christoph Grzeschik; Tammo Sternke; Alexander Grote; Manuel Popp; Dennis Becker; Hauke Müntinga; Holger Ahlers; Achim Peters; Claus Lämmerzahl; Klaus Sengstock; Naceur Gaaloul; Wolfgang Ertmer; Ernst M. Rasel

    2015-06-16T23:59:59.000Z

    Quantum sensors based on coherent matter-waves are precise measurement devices whose ultimate accuracy is achieved with Bose-Einstein condensates (BEC) in extended free fall. This is ideally realized in microgravity environments such as drop towers, ballistic rockets and space platforms. However, the transition from lab-based BEC machines to robust and mobile sources with comparable performance is a challenging endeavor. Here we report on the realization of a miniaturized setup, generating a flux of $4 \\times 10^5$ quantum degenerate $^{87}$Rb atoms every 1.6$\\,$s. Ensembles of $1 \\times 10^5$ atoms can be produced at a 1$\\,$Hz rate. This is achieved by loading a cold atomic beam directly into a multi-layer atom chip that is designed for efficient transfer from laser-cooled to magnetically trapped clouds. The attained flux of degenerate atoms is on par with current lab-based BEC experiments while offering significantly higher repetition rates. Additionally, the flux is approaching those of current interferometers employing Raman-type velocity selection of laser-cooled atoms. The compact and robust design allows for mobile operation in a variety of demanding environments and paves the way for transportable high-precision quantum sensors.

  11. Preparation of a high concentration of lithium-7 atoms in a magneto-optical trap

    SciTech Connect (OSTI)

    Zelener, B. B., E-mail: bobozel@mail.ru; Saakyan, S. A.; Sautenkov, V. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Manykin, E. A. [National Research Nuclear University “Moscow Engineering Physics Institute,” (Russian Federation); Zelener, B. V.; Fortov, V. E. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2014-11-15T23:59:59.000Z

    This study is aimed at obtaining high concentration of optically cooled lithium-7 atoms for preparing strongly interacting ultracold plasma and Rydberg matter. A special setup has been constructed, in which two high-power semiconductor lasers are used to cool lithium-7 atoms in a magneto-optical trap. At an optimum detuning of the cooling laser frequency and a magnetic field gradient of 35 G/cm, the concentration of ultracold lithium-7 atoms reaches about 10{sup 11} cm{sup ?3}. Additional independent information about the concentration and number of ultracold lithium-7 atoms on different sublevels of the ground state was obtained by using of an additional probing laser.

  12. Vapor-Phase Metalation by Atomic Layer Deposition in a Metal-Organic Framework

    E-Print Network [OSTI]

    encompass deposition onto micro- and nanopowders14 and coating of nanoparticle films15 as well as aerogel coating of porous materials that exhibit ultrahigh-aspect ratios.12,13 To date, some striking examples

  13. Magnetic field imaging with atomic Rb vapor Eugeniy E. Mikhailov,1

    E-Print Network [OSTI]

    Novikova, Irina

    Division, Naval Air Systems Command, Patuxent River, Maryland 20670, USA *Corresponding author: inovikova

  14. Interacting double dark resonances in a hot atomic vapor of helium

    E-Print Network [OSTI]

    S. Kumar; T. Lauprêtre; R. Ghosh; F. Bretenaker; F. Goldfarb

    2011-07-17T23:59:59.000Z

    We experimentally and theoretically study two different tripod configurations using metastable helium ($^4$He*), with the probe field polarization perpendicular and parallel to the quantization axis, defined by an applied weak magnetic field. In the first case, the two dark resonances interact incoherently and merge together into a single EIT peak with increasing coupling power. In the second case, we observe destructive interference between the two dark resonances inducing an extra absorption peak at the line center.

  15. Analysis of electron-beam vaporization of refractory metals

    SciTech Connect (OSTI)

    Kheshgi, H.S.; Gresho, P.M.

    1986-09-01T23:59:59.000Z

    An electron beam is focussed onto a small area on the surface of a refractory metal to locally raise the temperature and vaporize metal. At high vaporization rates the hot area is on the surface of a churning liquid-metal pool contained in a solid-metal skull which sits in a cooled crucible. Inner workings of the process are revealed by analysis of momentum, energy, and mass transfer. At the surface high temperature causes high vaporization rate and high vapor thrust, depressing the vapor/liquid surface. In the liquid pool surface-tension gradients and thermal buoyancy drive a (typically) chaotic flow. In the solid skull thermal conductivity and contact resistance regulate the rate of heat transfer from pool to crucible. Analyses of these phenomena together reveal process performance sensitivities - e.g., to depression size or to magnitude of surface-tension gradients. 12 refs., 3 figs.

  16. Ultrafast laser based coherent control methods for explosives detection

    SciTech Connect (OSTI)

    Moore, David Steven [Los Alamos National Laboratory

    2010-12-06T23:59:59.000Z

    The detection of explosives is a notoriously difficult problem, especially at stand-off, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring Optimal Dynamic Detection of Explosives (ODD-Ex), which exploits the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity to explosives signatures while dramatically improving specificity, particularly against matrix materials and background interferences. These goals are being addressed by operating in an optimal non-linear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe subpulses. Recent results will be presented.

  17. PHYSICAL REVIEW A 83, 013405 (2011) Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser

    E-Print Network [OSTI]

    Chu, Shih-I

    2011-01-01T23:59:59.000Z

    in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized to the advance of the intense and short pulse laser technology, the study of ATI phenomenon continues to attract) dynamics of atomic systems driven by intense laser fields. In this approach, the electron wave function

  18. Control of physical properties on solid surface via laser processing

    SciTech Connect (OSTI)

    Yonemoto, Yukihiro; Nishimura, Akihiko [Applied Laser Technology Institute, Japan Atomic Energy Agency, 65-20 Kizaki, Tsuruga, Fukui (Japan)

    2012-07-11T23:59:59.000Z

    In a safety operation of a nuclear power plant, vapor conditions such as a droplet or liquid membrane toward a solid surface of a heat exchanger and reactor vessel is important. In the present study, focusing on the droplet, the wettability on solid surface and surface free energy of solid are evaluated. In addition, wettability on a metal plate fabricated by laser processing is also considered for the nuclear engineering application.

  19. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, William C. (Albuquerque, NM); Seppala, Lynn (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser.

  20. Method for changing the cross section of a laser beam

    DOE Patents [OSTI]

    Sweatt, W.C.; Seppala, L.

    1995-12-05T23:59:59.000Z

    A technique is disclosed herein in which a circular optical beam, for example a copper vapor laser (CVL) beam, is converted to a beam having a profile other than circular, e.g. square or triangular. This is accomplished by utilizing a single optical mirror having a reflecting surface designed in accordance with a specifically derived formula in order to make the necessary transformation, without any substantial light loss and without changing substantially the intensity profile of the circular beam which has a substantially uniform intensity profile. In this way, the output beam can be readily directed into the dye cell of a dye laser. 4 figs.

  1. Gas lasers with wave-chaotic resonators

    E-Print Network [OSTI]

    Oleg Zaitsev

    2010-10-28T23:59:59.000Z

    Semiclassical multimode laser theory is extended to gas lasers with open two-dimensional resonators of arbitrary shape. The Doppler frequency shift of the linear-gain coefficient leads to an additional linear coupling between the modes, which, however, is shown to be negligible. The nonlinear laser equations simplify in the special case of wave-chaotic resonators. In the single-mode regime, the intensity of a chaotic laser, as a function of the mode frequency, displays a local minimum at the frequency of the atomic transition. The width of the minimum scales with the inhomogeneous linewidth, in contrast to the Lamb dip in uniaxial resonators whose width is given by the homogeneous linewidth.

  2. Laser stabilization using spectral hole burning

    E-Print Network [OSTI]

    L. Rippe; B. Julsgaard; A. Walther; S. Kröll

    2006-11-05T23:59:59.000Z

    We have frequency stabilized a Coherent CR699-21 dye laser to a transient spectral hole on the 606 nm transition in Pr^{+3}:Y_2SiO_5. A frequency stability of 1 kHz has been obtained on the 10 microsecond timescale together with a long-term frequency drift below 1 kHz/s. RF magnetic fields are used to repopulate the hyperfine levels allowing us to control the dynamics of the spectral hole. A detailed theory of the atomic response to laser frequency errors has been developed which allows us to design and optimize the laser stabilization feedback loop, and specifically we give a stability criterion that must be fulfilled in order to obtain very low drift rates. The laser stability is sufficient for performing quantum gate experiments in Pr^{+3}:Y_2SiO_5.

  3. Monitoring of vapor phase polycyclic aromatic hydrocarbons

    DOE Patents [OSTI]

    Vo-Dinh, Tuan; Hajaligol, Mohammad R.

    2004-06-01T23:59:59.000Z

    An apparatus for monitoring vapor phase polycyclic aromatic hydrocarbons in a high-temperature environment has an excitation source producing electromagnetic radiation, an optical path having an optical probe optically communicating the electromagnetic radiation received at a proximal end to a distal end, a spectrometer or polychromator, a detector, and a positioner coupled to the first optical path. The positioner can slidably move the distal end of the optical probe to maintain the distal end position with respect to an area of a material undergoing combustion. The emitted wavelength can be directed to a detector in a single optical probe 180.degree. backscattered configuration, in a dual optical probe 180.degree. backscattered configuration or in a dual optical probe 90.degree. side scattered configuration. The apparatus can be used to monitor an emitted wavelength of energy from a polycyclic aromatic hydrocarbon as it fluoresces in a high temperature environment.

  4. Hybrid Vapor Compression Adsorption System: Thermal Storage Using Hybrid Vapor Compression Adsorption System

    SciTech Connect (OSTI)

    None

    2012-01-04T23:59:59.000Z

    HEATS Project: UTRC is developing a new climate-control system for EVs that uses a hybrid vapor compression adsorption system with thermal energy storage. The targeted, closed system will use energy during the battery-charging step to recharge the thermal storage, and it will use minimal power to provide cooling or heating to the cabin during a drive cycle. The team will use a unique approach of absorbing a refrigerant on a metal salt, which will create a lightweight, high-energy-density refrigerant. This unique working pair can operate indefinitely as a traditional vapor compression heat pump using electrical energy, if desired. The project will deliver a hot-and-cold battery that provides comfort to the passengers using minimal power, substantially extending the driving range of EVs.

  5. Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

    DOE Patents [OSTI]

    Baker, Richard W. (Palo Alto, CA); Pinnau, Ingo (Palo Alto, CA); He, Zhenjie (Fremont, CA); Da Costa, Andre R. (Menlo Park, CA); Daniels, Ramin (San Jose, CA); Amo, Karl D. (Mountain View, CA); Wijmans, Johannes G. (Menlo Park, CA)

    2003-06-03T23:59:59.000Z

    A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

  6. Structures and Energetics of Some Potential Intermediates in Titanium Nitride Chemical Vapor Deposition: TiClm(NH2)n, TiClm(NH2)nNH, and TiClm(NH2)nN. An ab Initio

    E-Print Network [OSTI]

    Schlegel, H. Bernhard

    Structures and Energetics of Some Potential Intermediates in Titanium Nitride Chemical Vapor with these basis sets augmented by multiple sets of polarization and diffuse functions using the B3LYP optimized geometries. Bond dissociation energies, heats of atomization, heats of formation, and entropies have been

  7. Enhancement of magneto-optic effects via large atomic coherence in optically dense media RID B-9041-2008

    E-Print Network [OSTI]

    Sautenkov, V. A.; Lukin, M. D.; Bednar, CJ; Novikova, I.; Mikhailov, E.; Fleischhauer, M.; Velichansky, V. L.; Welch, George R.; Scully, Marlan O.

    2000-01-01T23:59:59.000Z

    -to-noise ratio. A proof-of-principle experiment is carried out in a dense vapor of Rb atoms. Applications such as optical magnetometry, the search for Violations of parity and time-reversal symmetry, and nonlinear optics at low light levels are feasible....

  8. alkali-metal vapor density: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    system: Alkali metal vapor in a single-mirror arrangement Physics Websites Summary: Secondary bifurcations of hexagonal patterns in a nonlinear optical system: Alkali metal vapor...

  9. Influence of laser beam profile on electromagnetically induced absorption

    SciTech Connect (OSTI)

    Cuk, S. M.; Radonjic, M.; Krmpot, A. J.; Nikolic, S. N.; Grujic, Z. D.; Jelenkovic, B. M. [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia)

    2010-12-15T23:59:59.000Z

    We compared, experimentally and theoretically, Hanle electromagnetically induced absorption (EIA) obtained using Gaussian and {Pi}-shaped laser beams 3 mm in diameter. The study was done by measuring the transmission of a laser locked to the F{sub g}=2{yields}F{sub e}=3 transition at the D{sub 2} line of {sup 87}Rb in a vacuum cell. EIA linewidths obtained for the two laser profiles were significantly different in the range of laser intensities 1-4 mW/cm{sup 2}. EIA with the {Pi}-shaped laser beam has a broad intensity maximum and linewidths larger than those obtained with the Gaussian beam profile. We also studied Hanle EIA by measuring the transmission of selected segments of the entire laser beam by placing a small movable aperture in front of the detector. Waveforms so obtained in Hanle EIA resonances were strongly influenced both by the radial distance of the transmitted segment from the beam center and by the radial profile of the laser beam. We show that outer regions of Gaussian beam, and central regions of the {Pi}-shaped beam generate the narrowest lines. The different behaviors of EIA owing to different beam profiles revealed by both theory and experiment indicate the importance of the radial profile of the laser beam for proper modeling of coherent effects in alkali metal vapors.

  10. Laser Directed Growth of Carbon-Based Nanostructures by Plasmon Resonant

    E-Print Network [OSTI]

    Cronin, Steve

    Laser Directed Growth of Carbon-Based Nanostructures by Plasmon Resonant Chemical Vapor Deposition the strong plasmon resonance of gold nanoparticles in the catalytic decomposition of CO to grow various forms of carbonaceous materials. Irradiating gold nanoparticles in a CO environment at their plasmon resonant frequency

  11. LASER PROCESSING AND DIAGNOSTICS (ME 290G) Two one and half lectures per week.

    E-Print Network [OSTI]

    Mofrad, Mohammad R. K.

    : conductive heat transfer, stress field, melting and solidification, surface vaporization, explosive phase transfer Time scales and analytical solutions 3.2 Stress field 3.3 Melting and solidification The classic of thin films 5.1 Modeling of energy absorption and heat transfer in pulsed laser irradiation of thin

  12. Particle size limits for quantitative aerosol analysis using laser-induced breakdown spectroscopy: Temporal considerations

    E-Print Network [OSTI]

    Hahn, David W.

    dissociation, vaporization and linear analyte response of an individual particle suspended in a gas stream individual silica microspheres in an aerosolized air stream was investigated using laser-induced breakdown of analyte signals for the 2.47 and 4.09-micrometer particles was observed to be approximately constant

  13. Atomic and molecular supernovae

    SciTech Connect (OSTI)

    Liu, W.

    1997-12-01T23:59:59.000Z

    Atomic and molecular physics of supernovae is discussed with an emphasis on the importance of detailed treatments of the critical atomic and molecular processes with the best available atomic and molecular data. The observations of molecules in SN 1987A are interpreted through a combination of spectral and chemical modelings, leading to strong constraints on the mixing and nucleosynthesis of the supernova. The non-equilibrium chemistry is used to argue that carbon dust can form in the oxygen-rich clumps where the efficient molecular cooling makes the nucleation of dust grains possible. For Type Ia supernovae, the analyses of their nebular spectra lead to strong constraints on the supernova explosion models.

  14. Optical analog of Rabi oscillation suppression due to atomic motion

    E-Print Network [OSTI]

    J. G. Muga; B. Navarro

    2005-05-13T23:59:59.000Z

    The Rabi oscillations of a two-level atom illuminated by a laser on resonance with the atomic transition may be suppressed by the atomic motion through averaging or filtering mechanisms. The optical analogs of these velocity effects are described. The two atomic levels correspond in the optical analogy to orthogonal polarizations of light and the Rabi oscillations to polarization oscillations in a medium which is optically active, naturally or due to a magnetic field. In the later case, the two orthogonal polarizations could be selected by choosing the orientation of the magnetic field, and one of them be filtered out. It is argued that the time-dependent optical polarization oscillations or their suppression are observable with current technology.

  15. Development of mixed-waste analysis capability for graphite furnace atomic absorption spectrophotometry

    SciTech Connect (OSTI)

    Bass, D.A.; TenKate, L.B.; Wroblewski, A.

    1995-03-01T23:59:59.000Z

    Graphite furnace atomic absorption spectrophotometer (GFAAS) are typically configured with ventilation to capture potentially toxic and corrosive gases emitted from the vaporization of sample aliquots. When radioactive elements are present, additional concerns (such as meeting safety guidelines and ALARA principles) must be addressed. This report describes a modification to a GFAAS that provides additional containment of vaporized sample aliquots. The modification was found to increase containment by a factor of 80, given expected operating conditions. The use of the modification allows more mixed-waste samples to be analyzed, permits higher levels of radioactive samples to be analyzed, or exposes the analyst to less airborne radioactivity. The containment apparatus was attached to a Perkin-Elmer Zeeman 5000 spectrophotometer for analysis of mixed-waste samples; however, it could also be used on other systems and in other applications where greater containment of vaporized material is desired.

  16. Analysis of laser remote fusion cutting based on a mathematical model

    SciTech Connect (OSTI)

    Matti, R. S. [Department of Engineering Sciences and Mathematics, Luleå University of Technology, S-971 87 Luleå (Sweden); Department of Mechanical Engineering, College of Engineering, University of Mosul, Mosul (Iraq); Ilar, T.; Kaplan, A. F. H. [Department of Engineering Sciences and Mathematics, Luleå University of Technology, S-971 87 Luleå (Sweden)

    2013-12-21T23:59:59.000Z

    Laser remote fusion cutting is analyzed by the aid of a semi-analytical mathematical model of the processing front. By local calculation of the energy balance between the absorbed laser beam and the heat losses, the three-dimensional vaporization front can be calculated. Based on an empirical model for the melt flow field, from a mass balance, the melt film and the melting front can be derived, however only in a simplified manner and for quasi-steady state conditions. Front waviness and multiple reflections are not modelled. The model enables to compare the similarities, differences, and limits between laser remote fusion cutting, laser remote ablation cutting, and even laser keyhole welding. In contrast to the upper part of the vaporization front, the major part only slightly varies with respect to heat flux, laser power density, absorptivity, and angle of front inclination. Statistical analysis shows that for high cutting speed, the domains of high laser power density contribute much more to the formation of the front than for low speed. The semi-analytical modelling approach offers flexibility to simplify part of the process physics while, for example, sophisticated modelling of the complex focused fibre-guided laser beam is taken into account to enable deeper analysis of the beam interaction. Mechanisms like recast layer generation, absorptivity at a wavy processing front, and melt film formation are studied too.

  17. Laser program annual report, 1980

    SciTech Connect (OSTI)

    Coleman, L.W.; Krupke, W.F.; Strack, J.R. (eds.) [eds.

    1981-06-01T23:59:59.000Z

    Volume 2 contains five sections that cover the areas of target design, target fabrication, diagnostics, and fusion experiments. Section 3 reports on target design activities, plasma theory and simulation, code development, and atomic theory. Section 4 presents the accomplishments of the Target Fabrication Group, Section 5 contains the results of our diagnostics development, and Section 6 describes advances made in the management and analysis of experimental data. Finally, Section 7 in Volume 2 reports the results of laser target experiments conducted during the year.

  18. Vapor Power Systems MAE 4263 Final Exam

    E-Print Network [OSTI]

    of formation on pages 162 and 163 114:23 ( 941:4) BTU/lbmolfuel = 9 18:016 ( 5774:6) + 8 44:011 ( 3846:7) + Qout = 114:23 ( 785:1) (9 18:016 ( 5774:6) + 8 44:011 ( 3846:7)) 114:23 Qout = 2:183 106 BTU/lbmolfuel = 19112 BTU/lbmfuel Answer (40 points): LHV= 19100 BTU/lbmfuel [19268 for gasi...ed fuel] 3. Atomic

  19. PHARAO Laser Source Flight Model: Design and Performances

    E-Print Network [OSTI]

    Lévèque, Thomas; Esnault, François-Xavier; Delaroche, Christophe; Massonnet, Didier; Grosjean, Olivier; Buffe, Fabrice; Torresi, Patrizia; Bomer, Thierry; Pichon, Alexandre; Béraud, Pascal; Lelay, Jean-Pierre; Thomin, Stéphane; Laurent, Philippe

    2015-01-01T23:59:59.000Z

    In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.

  20. Comprehensive online Atomic Database Management System (DBMS) with Highly Qualified Computing Capabilities

    E-Print Network [OSTI]

    Tahat, Amani

    2011-01-01T23:59:59.000Z

    The intensive need of atomic data is expanding continuously in a wide variety of applications (e.g. fusion energy and astrophysics, laser-produced, plasma researches, and plasma processing).This paper will introduce our ongoing research work to build a comprehensive, complete, up-to-date, user friendly and online atomic Database Management System (DBMS) namely called AIMS by using SQLite (http://www.sqlite.org/about.html)(8). Programming language tools and techniques will not be covered here. The system allows the generation of various atomic data based on professional online atomic calculators. The ongoing work is a step forward to bring detailed atomic model accessible to a wide community of laboratory and astrophysical plasma diagnostics. AIMS is a professional worldwide tool for supporting several educational purposes and can be considered as a complementary database of IAEA atomic databases. Moreover, it will be an exceptional strategy of incorporating the output data of several atomic codes to external ...

  1. Metal atomization spray nozzle

    DOE Patents [OSTI]

    Huxford, T.J.

    1993-11-16T23:59:59.000Z

    A spray nozzle for a magnetohydrodynamic atomization apparatus has a feed passage for molten metal and a pair of spray electrodes mounted in the feed passage. The electrodes, diverging surfaces which define a nozzle throat and diverge at an acute angle from the throat. Current passes through molten metal when fed through the throat which creates the Lorentz force necessary to provide atomization of the molten metal. 6 figures.

  2. Atomizing nozzle and method

    DOE Patents [OSTI]

    Ting, Jason (Ames, IA); Anderson, Iver E. (Ames, IA); Terpstra, Robert L. (Ames, IA)

    2000-03-16T23:59:59.000Z

    A high pressure close-coupled gas atomizing nozzle includes multiple discrete gas jet discharge orifices having aerodynamically designed convergent-divergent geometry with an first converging section communicated to a gas supply manifold and to a diverging section by a constricted throat section to increase atomizing gas velocity. The gas jet orifices are oriented at gas jet apex angle selected relative to the melt supply tip apex angle to establish a melt aspiration condition at the melt supply tip.

  3. Atomic mass compilation 2012

    SciTech Connect (OSTI)

    Pfeiffer, B., E-mail: bpfeiffe@uni-mainz.de [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); Venkataramaniah, K. [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India)] [Sri Sathya Sai Institute of Higher Learning, Prasanthinilayam (India); Czok, U. [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)] [II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany); Scheidenberger, C. [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany) [GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt (Germany); II. Physikalisches Institut, Justus-Liebig-Universität Gießen, Gießen (Germany)

    2014-03-15T23:59:59.000Z

    Atomic mass reflects the total binding energy of all nucleons in an atomic nucleus. Compilations and evaluations of atomic masses and derived quantities, such as neutron or proton separation energies, are indispensable tools for research and applications. In the last decade, the field has evolved rapidly after the advent of new production and measuring techniques for stable and unstable nuclei resulting in substantial ameliorations concerning the body of data and their precision. Here, we present a compilation of atomic masses comprising the data from the evaluation of 2003 as well as the results of new measurements performed. The relevant literature in refereed journals and reports as far as available, was scanned for the period beginning 2003 up to and including April 2012. Overall, 5750 new data points have been collected. Recommended values for the relative atomic masses have been derived and a comparison with the 2003 Atomic Mass Evaluation has been performed. This work has been carried out in collaboration with and as a contribution to the European Nuclear Structure and Decay Data Network of Evaluations.

  4. Controlling the vapor pressure of a mercury lamp

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); George, William A. (Rockport, MA)

    1988-01-01T23:59:59.000Z

    The invention described herein discloses a method and apparatus for controlling the Hg vapor pressure within a lamp. This is done by establishing and controlling two temperature zones within the lamp. One zone is colder than the other zone. The first zone is called the cold spot. By controlling the temperature of the cold spot, the Hg vapor pressure within the lamp is controlled. Likewise, by controlling the Hg vapor pressure of the lamp, the intensity and linewidth of the radiation emitted from the lamp is controlled.

  5. In-well vapor stripping drilling and characterization work plan

    SciTech Connect (OSTI)

    Koegler, K.J.

    1994-03-13T23:59:59.000Z

    This work plan provides the information necessary for drilling, sampling, and hydrologic testing of wells to be completed in support of a demonstration of the in-well vapor stripping system. The in-well vapor stripping system is a remediation technology designed to preferentially extract volatile organic compounds (VOCs) from contaminated groundwater by converting them to a vapor phase. Air-lift pumping is used to lift and aerate groundwater within the well. The volatiles escaping the aerated water are drawn off by a slight vacuum and treated at the surface while the water is allowed to infiltrate the vadose zone back to the watertable.

  6. Plateau structures in potential scattering in a strong laser field

    SciTech Connect (OSTI)

    Cerkic, A. [Federal Meteorological Institute, Bardakcije 12, 71000 Sarajevo (Bosnia and Herzegowina); Milosevic, D.B. [Faculty of Science, University of Sarajevo, Zmaja od Bosne 35, 71000 Sarajevo (Bosnia and Herzegowina); Max-Born-Institut, Max-Born-Strasse 2a, 12489 Berlin (Germany)

    2004-11-01T23:59:59.000Z

    Electron-atom scattering in a strong laser field is analyzed using the strong-field approximation and modeling elastic scattering of electrons by atoms with a realistic analytical potential derived from an independent-particle model. The results that include both direct scattering and scattering with a repeated scattering (rescattering) are presented. In the latter case, in the intermediate step of the process, the electron can absorb the energy from the laser field and additional plateau structures appear. The features of these plateaus and their cutoffs are analyzed for various incident electron energies and scattering angles, for different laser intensities, and for various atomic gases. The boundaries of these plateaus are compared with classical estimates.

  7. Enhanced Attenuation Technologies: Passive Soil Vapor Extraction

    SciTech Connect (OSTI)

    Vangelas, K.; Looney, B.; Kamath, R.; Adamson, D.; Newell, C.

    2010-03-15T23:59:59.000Z

    Passive soil vapor extraction (PSVE) is an enhanced attenuation (EA) approach that removes volatile contaminants from soil. The extraction is driven by natural pressure gradients between the subsurface and atmosphere (Barometric Pumping), or by renewable sources of energy such as wind or solar power (Assisted PSVE). The technology is applicable for remediating sites with low levels of contamination and for transitioning sites from active source technologies such as active soil vapor extraction (ASVE) to natural attenuation. PSVE systems are simple to design and operate and are more cost effective than active systems in many scenarios. Thus, PSVE is often appropriate as an interim-remedial or polishing strategy. Over the past decade, PSVE has been demonstrated in the U.S. and in Europe. These demonstrations provide practical information to assist in selecting, designing and implementing the technology. These demonstrations indicate that the technology can be effective in achieving remedial objectives in a timely fashion. The keys to success include: (1) Application at sites where the residual source quantities, and associated fluxes to groundwater, are relatively low; (2) Selection of the appropriate passive energy source - barometric pumping in cases with a deep vadose zone and barrier (e.g., clay) layers that separate the subsurface from the atmosphere and renewable energy assisted PSVE in other settings and where higher flow rates are required. (3) Provision of sufficient access to the contaminated vadose zones through the spacing and number of extraction wells. This PSVE technology report provides a summary of the relevant technical background, real-world case study performance, key design and cost considerations, and a scenario-based cost evaluation. The key design and cost considerations are organized into a flowchart that dovetails with the Enhanced Attenuation: Chlorinated Organics Guidance of the Interstate Technology and Regulatory Council (ITRC). The PSVE flowchart provides a structured process to determine if the technology is, or is not, reasonable and defensible for a particular site. The central basis for that decision is the expected performance of PSVE under the site specific conditions. Will PSVE have sufficient mass removal rates to reduce the release, or flux, of contamination into the underlying groundwater so that the site can meet it overall remedial objectives? The summary technical information, case study experiences, and structured decision process provided in this 'user guide' should assist environmental decision-makers, regulators, and engineers in selecting and successfully implementing PSVE at appropriate sites.

  8. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

    Mark J. Bergander

    2005-08-29T23:59:59.000Z

    The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

  9. Phase Synchronization between Two Superradiant Lasers

    E-Print Network [OSTI]

    Joshua M. Weiner; Kevin C. Cox; Justin G. Bohnet; James K. Thompson

    2015-03-22T23:59:59.000Z

    We experimentally demonstrate synchronization between two distinct ensembles of cold atoms undergoing steady state superradiance within a single longitudinal and transverse mode of the same optical cavity. The synchronization process is studied first in terms of the time dynamics of re-synchronization when the phase alignment of the two oscillators is abruptly broken. We also observe the steady state behavior of the lasers as their relative frequency is continuously varied. This system has the potential to realize a non-equilibrium quantum phase transition and could inform future implementations of milliHertz linewidth lasers.

  10. Development of a wet vapor homogeneous liquid metal MHD power system. Final report

    SciTech Connect (OSTI)

    Branover, H.; Unger, Y.; El-Boher, A.; Schweitzer, H.

    1991-09-01T23:59:59.000Z

    A feasibility study for the approval of liquid metal seeds recovery from a liquid metal vapor-inert gas mixture was conducted and presented in this report. The research activity included background studies on processes relating to mixing stream condenser performance, parametric studies and its experimental validation. The condensation process under study includes mass transfer phenomena combined with heat transfer and phase change. Numerical methods were used in order to solve the dynamic equations and to carry out the parametric study as well as the experimental data reduction. The MSC performance is highly effected by droplet diameter, thus the possibility of atomizing liquid metals were experimentally investigated. The results are generalized and finally used for a set of recommendations by which the recovery of seeds is expected to be feasible.

  11. Plasma-enhanced chemical vapor deposition of graphene on copper substrates

    SciTech Connect (OSTI)

    Woehrl, Nicolas, E-mail: nicolas.woehrl@uni-due.de; Schulz, Stephan [Faculty of Chemistry and CENIDE, University Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)] [Faculty of Chemistry and CENIDE, University Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Ochedowski, Oliver; Gottlieb, Steven [Faculty of Physics and CENIDE, University Duisburg Essen, Lotharstraße 1, 47057 Duisburg (Germany)] [Faculty of Physics and CENIDE, University Duisburg Essen, Lotharstraße 1, 47057 Duisburg (Germany); Shibasaki, Kosuke [Institute of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)] [Institute of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)

    2014-04-15T23:59:59.000Z

    A plasma enhanced vapor deposition process is used to synthesize graphene from a hydrogen/methane gas mixture on copper samples. The graphene samples were transferred onto SiO{sub 2} substrates and characterized by Raman spectroscopic mapping and atomic force microscope topographical mapping. Analysis of the Raman bands shows that the deposited graphene is clearly SLG and that the sheets are deposited on large areas of several mm{sup 2}. The defect density in the graphene sheets is calculated using Raman measurements and the influence of the process pressure on the defect density is measured. Furthermore the origin of these defects is discussed with respect to the process parameters and hence the plasma environment.

  12. X-ray diffraction analysis of InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition

    SciTech Connect (OSTI)

    Nittono, T.; Hyuga, F. [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)] [NTT System Electronics Laboratories 3-1, Morinosato Wakamiya, Atsugi-shi, Kanagawa, 243-01 (Japan)

    1997-03-01T23:59:59.000Z

    InGaP/GaAs heterointerfaces grown by metalorganic chemical vapor deposition have been characterized by a high-resolution x-ray diffraction analysis of multiple quantum well structures. The flow of AsH{sub 3} to InGaP surface produces an InGaAs-like interfacial layer at the GaAs-on-InGaP interface, indicating P atoms of the InGaP surface are easily replaced by As atoms. The flow of PH{sub 3} to GaAs surface, on the other hand, does not make any detectable interfacial layer, indicating that almost no As atoms of the GaAs surface are replaced by P atoms. It is also found that the flow of trimethylgallium (TMG) to the InGaP surface produces a GaP-like interfacial layer. This interfacial layer is probably formed by the reaction between TMG and excessive P atoms on the InGaP surface or residual PH{sub 3} in the growth chamber. {copyright} {ital 1997 American Institute of Physics.}

  13. Light-induced gauge fields for ultracold atoms

    E-Print Network [OSTI]

    N. Goldman; G. Juzeliunas; P. Ohberg; I. B. Spielman

    2014-12-12T23:59:59.000Z

    Gauge fields are central in our modern understanding of physics at all scales. At the highest energy scales known, the microscopic universe is governed by particles interacting with each other through the exchange of gauge bosons. At the largest length scales, our universe is ruled by gravity, whose gauge structure suggests the existence of a particle - the graviton - that mediates the gravitational force. At the mesoscopic scale, solid-state systems are subjected to gauge fields of different nature: materials can be immersed in external electromagnetic fields, but they can also feature emerging gauge fields in their low-energy description. In this review, we focus on another kind of gauge field: those engineered in systems of ultracold neutral atoms. In these setups, atoms are suitably coupled to laser fields that generate effective gauge potentials in their description. Neutral atoms "feeling" laser-induced gauge potentials can potentially mimic the behavior of an electron gas subjected to a magnetic field, but also, the interaction of elementary particles with non-Abelian gauge fields. Here, we review different realized and proposed techniques for creating gauge potentials - both Abelian and non-Abelian - in atomic systems and discuss their implication in the context of quantum simulation. While most of these setups concern the realization of background and classical gauge potentials, we conclude with more exotic proposals where these synthetic fields might be made dynamical, in view of simulating interacting gauge theories with cold atoms.

  14. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    A. Deltuva

    2012-03-28T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  15. Universal bosonic tetramers of dimer-atom-atom structure

    E-Print Network [OSTI]

    Deltuva, A

    2012-01-01T23:59:59.000Z

    Unstable four-boson states having an approximate dimer-atom-atom structure are studied using momentum-space integral equations for the four-particle transition operators. For a given Efimov trimer the universal properties of the lowest associated tetramer are determined. The impact of this tetramer on the atom-trimer and dimer-dimer collisions is analyzed. The reliability of the three-body dimer-atom-atom model is studied.

  16. BNL | CO2 Laser

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    CO2 Laser The ATF is one of the only two facilities worldwide operating picosecond, terawatt-class CO2 lasers. Our laser system consists of a picoseconds pulse-injector based on...

  17. FREE-ELECTRON LASERS

    E-Print Network [OSTI]

    Sessler, A.M.

    2008-01-01T23:59:59.000Z

    Variable-Wiggler Free-Electron-Laser Oscillat.ion. Phys. :_.The Los Alamos Free Electron Laser: Accelerator Perfoemance.First Operation of a Free-Electron Laser. Phys . __ Rev~.

  18. Spectroscopy of barium atoms in liquid and solid helium matrices

    SciTech Connect (OSTI)

    Lebedev, V.; Moroshkin, P.; Weis, A. [Departement de Physique, Universite de Fribourg, Chemin du Musee 3, CH-1700 Fribourg (Switzerland)

    2011-08-15T23:59:59.000Z

    We present an exhaustive overview of optical absorption and laser-induced fluorescence lines of Ba atoms in liquid and solid helium matrices in visible and near-infrared spectral ranges. Due to the increased density of isolated atoms, we have found a large number of spectral lines that were not observed in condensed helium matrices before. We have also measured the lifetimes of metastable states. The lowest {sup 3}D{sub 1} metastable state has lifetime of 2.6 s and can be used as an intermediate state in two-step excitations of high-lying states. Various matrix-induced radiationless population transfer channels have been identified.

  19. Final Scientific/Technical Report. A closed path methane and water vapor gas analyzer

    SciTech Connect (OSTI)

    Liukang, Xu; Dayle, McDermitt; Tyler, Anderson; Brad, Riensche; Anatoly, Komissarov; Julie, Howe

    2012-05-01T23:59:59.000Z

    Robust, economical, low-power and reliable closed-path methane (CH4), carbon dioxide (CO2), and water vapor (H2O) analyzers suitable for long-term measurements are not readily available commercially. Such analyzers are essential for quantifying the amount of CH4 and CO2 released from various ecosystems (wetlands, rice paddies, forests, etc.) and other surface contexts (e.g. landfills, animal husbandry lots, etc.), and for understanding the dynamics of the atmospheric CH4 and CO2 budget and their impact on climate change and global warming. The purpose of this project is to develop a closed-path methane, carbon dioxide gas and water vapor analyzer capable of long-term measurements in remote areas for global climate change and environmental research. The analyzer will be capable of being deployed over a wide range of ecosystems to understand methane and carbon dioxide exchange between the atmosphere and the surface. Measurements of methane and carbon dioxide exchange need to be made all year-round with limited maintenance requirements. During this Phase II effort, we successfully completed the design of the electronics, optical bench, trace gas detection method and mechanical infrastructure. We are using the technologies of two vertical cavity surface emitting lasers, a multiple-pass Herriott optical cell, wavelength modulation spectroscopy and direct absorption to measure methane, carbon dioxide, and water vapor. We also have designed the instrument application software, Field Programmable Gate Array (FPGA), along with partial completion of the embedded software. The optical bench has been tested in a lab setting with very good results. Major sources of optical noise have been identified and through design, the optical noise floor is approaching -60dB. Both laser modules can be temperature controlled to help maximize the stability of the analyzer. Additionally, a piezo electric transducer has been utilized to randomize the noise introduced from potential etalons. It is expected that all original specifications contained within the initial proposal will be met. We are currently in the beginning stages of assembling the first generation prototypes and finalizing the remaining design elements. The first prototypes will initially be tested in our environmental calibration chamber in which specific gas concentrations, temperature and humidity levels can be controlled. Once operation in this controlled setting is verified, the prototypes will be deployed at LI-COR�¢����s Experimental Research Station (LERS). Deployment at the LERS site will test the instrument�¢����s robustness in a real-world situation.

  20. Photoinitiated chemical vapor depostion [sic] : mechanism and applications

    E-Print Network [OSTI]

    Baxamusa, Salmaan Husain

    2009-01-01T23:59:59.000Z

    Photoinitiated chemical vapor deposition (piCVD) is developed as a simple, solventless, and rapid method for the deposition of swellable hydrogels and functional hydrogel copolymers. Mechanistic experiments show that piCVD ...