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Sample records for 938nm cladding pumped

  1. High Power 938nm Cladding Pumped Fiber Laser

    SciTech Connect

    Dawson, J; Beach, R; Brobshoff, A; Liao, Z; Payne, S; Pennington, D; Taylor, L; Hackenberg, W; Bonaccini, D

    2002-12-26

    We have developed a Nd:doped cladding pumped fiber amplifier, which operates at 938nm with greater than 2W of output power. The core co-dopants were specifically chosen to enhance emission at 938nm. The fiber was liquid nitrogen cooled in order to achieve four-level laser operation on a laser transition that is normally three level at room temperature, thus permitting efficient cladding pumping of the amplifier. Wavelength selective attenuation was induced by bending the fiber around a mandrel, which permitted near complete suppression of amplified spontaneous emission at 1088nm. We are presently seeking to scale the output of this laser to 10W. We will discuss the fiber and laser design issues involved in scaling the laser to the 10W power level and present our most recent results.

  2. 938 nm Nd-Doped High Power Cladding Pumped Fiber Amplifier

    SciTech Connect

    Dawson, J; Beach, R; Drobshoff, A; Liao, Z; Pennington, D; Payne, S; Taylor, L; Hackenberg, W; Bonaccini, D

    2002-09-19

    2.1W of 938nm light has been produced in an Nd{sup 3+} doped fiber amplifier. Wavelength dependent bend losses can be employed to minimize 1088nm amplified spontaneous emission giving the optical fiber a distinct advantage over bulk media.

  3. Nd:YAG laser diode-pumped directly into the emitting level at 938 nm.

    PubMed

    Sangla, Damien; Balembois, François; Georges, Patrick

    2009-06-08

    We present the first demonstration of Nd:YAG laser pumped directly in band at 938 nm with a high-brightness fiber-coupled laser diode. Up to 6 W of CW laser emission at 1064 nm have been obtained under an absorbed pump power of 28 W at 938 nm. A comparison between 808 nm and 938 nm pumping, realized by thermal cartography, demonstrates the very low heat generation of in-band pumping. Numerical simulations were also implemented to study and discuss the laser performance of our system.

  4. Diode-pumped passively Q-switched Nd:GAGG laser at 938 nm with V3+:YAG saturable absorber

    NASA Astrophysics Data System (ADS)

    Liu, S. D.; Zhang, B. T.; He, J. L.; Yang, H. W.; Xu, J. L.; Liu, F. Q.; Yang, J. F.; Yang, X. Q.; Huang, H. T.

    2010-10-01

    The continuous wave (CW) and passively Q-switched Nd:Gd3AlxGa5-xO12 (Nd:GAGG) laser operation at 938 nm have been realized for the first time. The maximum CW output power of 0.44 W was obtained under the absorbed pump power of 8.54 W, corresponding to the slope efficiency of 7.8% and optical-to-optical efficiency of 5.2% respectively. A V3+:YAG saturable absorber crystal with the initial transmission of 97% was used for the passive Q-switching regime. The maximum average output power of 0.19 W was achieved with the minimum pulse width of 358 ns and Q-switched repetition rate of 116 kHz. The corresponding single pulse energy and pulse peak power were determined to be 1.6 μJ and 4.6 W, respectively.

  5. Cladding For Transversely-Pumped Laser Rod

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  6. Cladding For Transversely-Pumped Laser Rod

    NASA Technical Reports Server (NTRS)

    Byer, Robert L.; Fan, Tso Yee

    1989-01-01

    Combination of suitable dimensioning and cladding of neodymium:yttrium aluminum garnet of similar solid-state laser provides for more efficient utilization of transversely-incident pump light from diode lasers. New design overcomes some of limitations of longitudinal- and older transverse-pumping concepts and promotes operation at higher output powers in TEM00 mode.

  7. Cascaded-cladding-pumped cascaded Raman fiber amplifier.

    PubMed

    Jiang, Huawei; Zhang, Lei; Feng, Yan

    2015-06-01

    The conversion efficiency of double-clad Raman fiber laser is limited by the cladding-to-core area ratio. To get high conversion efficiency, the inner-cladding-to-core area ratio has to be less than about 8, which limits the brightness enhancement. To overcome the problem, a cascaded-cladding-pumped cascaded Raman fiber laser with multiple-clad fiber as the Raman gain medium is proposed. A theoretical model of Raman fiber amplifier with multiple-clad fiber is developed, and numerical simulation proves that the proposed scheme can improve the conversion efficiency and brightness enhancement of cladding pumped Raman fiber laser.

  8. Phosphate-core silica-clad Er/Yb-doped optical fiber and cladding pumped laser.

    PubMed

    Egorova, O N; Semjonov, S L; Velmiskin, V V; Yatsenko, Yu P; Sverchkov, S E; Galagan, B I; Denker, B I; Dianov, E M

    2014-04-07

    We present a composite optical fiber with a Er/Yb co-doped phosphate-glass core in a silica glass cladding as well as cladding pumped laser. The fabrication process, optical properties, and lasing parameters are described. The slope efficiency under 980 nm cladding pumping reached 39% with respect to the absorbed pump power and 28% with respect to the coupled pump power. Due to high doping level of the phosphate core optimal length was several times shorter than that of silica core fibers.

  9. Cladding-pumped erbium-doped multicore fiber amplifier.

    PubMed

    Abedin, K S; Taunay, T F; Fishteyn, M; DiGiovanni, D J; Supradeepa, V R; Fini, J M; Yan, M F; Zhu, B; Monberg, E M; Dimarcello, F V

    2012-08-27

    A cladding pumped multicore erbium-doped fiber amplifier for simultaneous amplification of 6 channels is demonstrated. Peak gain over 32 dB has been obtained at a wavelength of 1560 nm and the bandwidth measured at 20-dB gain was about 35 nm. Numerical modeling of cladding pumped multicore erbium-doped amplifier was also performed to study the properties of the amplifier. The results of experiment and simulation are found to be in good agreement.

  10. Compact cladding-pumped planar waveguide amplifier and fabrication method

    DOEpatents

    Bayramian, Andy J.; Beach, Raymond J.; Honea, Eric; Murray, James E.; Payne, Stephen A.

    2003-10-28

    A low-cost, high performance cladding-pumped planar waveguide amplifier and fabrication method, for deployment in metro and access networks. The waveguide amplifier has a compact monolithic slab architecture preferably formed by first sandwich bonding an erbium-doped core glass slab between two cladding glass slabs to form a multi-layer planar construction, and then slicing the construction into multiple unit constructions. Using lithographic techniques, a silver stripe is deposited and formed at a top or bottom surface of each unit construction and over a cross section of the bonds. By heating the unit construction in an oven and applying an electric field, the silver stripe is then ion diffused to increase the refractive indices of the core and cladding regions, with the diffusion region of the core forming a single mode waveguide, and the silver diffusion cladding region forming a second larger waveguide amenable to cladding pumping with broad area diodes.

  11. Cladding for transverse-pumped solid-state laser

    NASA Technical Reports Server (NTRS)

    Byer, Robert L. (Inventor); Fan, Tso Y. (Inventor)

    1989-01-01

    In a transverse pumped, solid state laser, a nonabsorptive cladding surrounds a gain medium. A single tranverse mode, namely the Transverse Electromagnetic (TEM) sub 00 mode, is provided. The TEM sub 00 model has a cross sectional diameter greater than a transverse dimension of the gain medium but less than a transverse dimension of the cladding. The required size of the gain medium is minimized while a threshold for laser output is lowered.

  12. A cladding-pumped, tunable holmium doped fiber laser.

    PubMed

    Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John; Carter, Adrian

    2013-11-18

    We present a tunable, high power cladding-pumped holmium doped fiber laser. The laser generated >15 W CW average power across a wavelength range of 2.043 - 2.171 μm, with a maximum output power of 29.7 W at 2.120 μm. The laser also produced 18.2 W when operating at 2.171 µm. To the best of our knowledge this is the highest power operation of a holmium doped laser at a wavelength >2.15 µm. We discuss the significance of background losses and fiber design for achieving efficient operation in holmium doped fibers.

  13. Air-clad fibers: pump absorption assisted by chaotic wave dynamics?

    PubMed

    Mortensen, Niels A

    2007-07-09

    Wave chaos is a concept which has already proved its practical usefulness in design of double-clad fibers for cladding-pumped fiber lasers and fiber amplifiers. In general, classically chaotic geometries will favor strong pump absorption and we address the extent of chaotic wave dynamics in typical air-clad geometries. While air-clad structures supporting sup-wavelength convex air-glass interfaces (viewed from the high-index side) will promote chaotic dynamics we find guidance of regular whispering-gallery modes in air-clad structures resembling an overall cylindrical symmetry. Highly symmetric air-clad structures may thus suppress the pump-absorption efficiency eta below the ergodic scaling law etainfinity Ac/Acl, where Ac and Acl are the areas of the rare-earth doped core and the cladding, respectively.

  14. Comparison of fiber lasers based on distributed side-coupled cladding-pumped fibers and double-cladding fibers.

    PubMed

    Huang, Zhihe; Cao, Jianqiu; Guo, Shaofeng; Chen, Jinbao; Xu, Xiaojun

    2014-04-01

    We compare both analytically and numerically the distributed side-coupled cladding-pumped (DSCCP) fiber lasers and double cladding fiber (DCF) lasers. We show that, through optimization of the coupling and absorbing coefficients, the optical-to-optical efficiency of DSCCP fiber lasers can be made as high as that of DCF lasers. At the same time, DSCCP fiber lasers are better than the DCF lasers in terms of thermal management.

  15. Pump radiation distribution in multi-element first cladding laser fibres

    SciTech Connect

    Mel'kumov, Mikhail A; Bufetov, Igor' A; Bubnov, M M; Shubin, Aleksei V; Semenov, S L; Dianov, Evgenii M

    2005-11-30

    Pump radiation transfer is studied experimentally in multi-element first cladding laser fibres. A model of this process is proposed, which is in good agreement with experimental results. An all-fibre single-mode cw ytterbium laser based on a three-element first cladding fibre with an output power of 100W is fabricated. (lasers)

  16. Ytterbium-doped all glass leakage channel fibers with highly fluorine-doped silica pump cladding.

    PubMed

    Dong, Liang; McKay, Hugh A; Fu, Libin; Ohta, Michiharu; Marcinkevicius, Andrius; Suzuki, Shigeru; Fermann, Martin E

    2009-05-25

    All glass leakage channel fibers have been demonstrated to be a potential practical solution for power scaling in fiber lasers beyond the nonlinear limits in conventional large mode area fibers. The all glass nature with absence of any air holes is especially useful for allowing the fibers to be used and fabricated much like conventional fibers. Previously, double clad active all glass leakage channel fibers used low index polymer as a pump guide with the drawbacks of being less reliable at high pump powers and not being able to change fiber outer diameter independent of pump guide dimension. In this work, we demonstrate, for the first time, ytterbium-doped double clad all glass leakage channel fibers with highly fluorine-doped silica as pump cladding. The new all glass leakage channel fibers have no polymer in the pump path and have independent control of fiber outer diameters and pump cladding dimension, and, therefore, enable designs with smaller pump guide for high pump absorption and, at the same time, with large fiber diameters to minimize micro and macro bending effects, a much desired features for large core fibers where intermodal coupling can be an issue due to a much increased mode density. An ytterbium-doped double clad PM fiber with core diameter of 80 microm is also reported, which can be coiled in 76 cm diameter coils.

  17. Clad-pumped Er-nanoparticle-doped fiber laser (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Baker, Colin C.; Friebele, E. Joseph; Rhonehouse, Daniel L.; Marcheschi, Barbara A.; Peele, John R.; Kim, Woohong; Sanghera, Jasbinder S.; Zhang, Jun; Chen, Youming; Pattnaik, Radha K.; Dubinskii, Mark

    2017-03-01

    Erbium-doped fiber lasers are attractive for directed energy weapons applications because they operate in a wavelength region that is both eye-safer and a window of high atmospheric transmission. For these applications a clad-pumped design is desirable, but the Er absorption must be high because of the areal dilution of the doped core vs. the pump cladding. High Er concentrations typically lead to Er ion clustering, resulting in quenching and upconversion. Nanoparticle (NP) doping of the core overcomes these problems by physically surrounding the Er ions with a cage of Al and O in the NP, which keeps them separated to minimize excited state energy transfer. A significant issue is obtaining high Er concentrations without the NP agglomeration that degrades the optical properties of the fiber core. We have developed the process for synthesizing stable Er-NP suspension which have been used to fabricate EDFs with Er concentrations >90 dB/m at 1532 nm. Matched clad fibers have been evaluated in a core-pumped MOPA with pump and signal wavelengths of 1475 and 1560 nm, respectively, and efficiencies of 72% with respect to absorbed pump have been obtained. We have fabricated both NP- and solution-doped double clad fibers, which have been measured in a clad-pumped laser testbed using a 1532 nm pump. The 1595 nm laser efficiency of the NP-doped fiber was 47.7%, which is high enough for what is believed to be the first laser experiment with the cladding pumped, NP-doped fiber. Further improvements are likely with a shaped cladding and new low-index polymer coatings with lower absorption in the 1500 - 1600 nm range.

  18. High-performace cladding-pumped erbium-doped fibre laser and amplifier

    SciTech Connect

    Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Lipatov, D S; Vechkanov, N N; Guryanov, Aleksei N

    2012-05-31

    We report cladding-pumped erbium-doped fibre laser and amplifier configurations. Through fibre design optimisation, we have achieved a record-high laser slope efficiency, 40 % with respect to absorbed pump power ({lambda} = 976 nm), and an output power of 7.5 W. The erbium-doped fibre amplifier efficiency reaches 32 %.

  19. The features of the optical pumping active fibers with three-piece inner clad

    NASA Astrophysics Data System (ADS)

    Bochkov, Alexander V.; Slobozhanina, Mariya G.

    2017-01-01

    This paper presents simple model of distribution of the pump radiation in active three-piece inner clad fibers (GTWave3) and analytical solutions of the relevant differential equations. Based on these solutions has been produced the analysis of the dependence distribution of the pump radiation and value of the effective length GTWave3 from key parameters of this type of a fiber (the active-region absorption coefficient and the coupling coefficients). Also in work presents comparison of the pump distribution into the GTWave3 and GTWave2 (two-piece inner clad) fibers.

  20. High power operation of cladding pumped holmium-doped silica fibre lasers.

    PubMed

    Hemming, Alexander; Bennetts, Shayne; Simakov, Nikita; Davidson, Alan; Haub, John; Carter, Adrian

    2013-02-25

    We report the highest power operation of a resonantly cladding-pumped, holmium-doped silica fibre laser. The cladding pumped all-glass fibre utilises a fluorine doped glass layer to provide low loss cladding guidance of the 1.95 µm pump radiation. The operation of both single mode and large-mode area fibre lasers was demonstrated, with up to 140 W of output power achieved. A slope efficiency of 59% versus launched pump power was demonstrated. The free running emission was measured to be 2.12-2.15 µm demonstrating the potential of this architecture to address the long wavelength operation of silica based fibre lasers with high efficiency.

  1. Highly scalable, resonantly cladding-pumped, Er-doped fiber laser with record efficiency.

    PubMed

    Dubinskii, M; Zhang, J; Ter-Mikirtychev, V

    2009-05-15

    We report the performance of a resonantly cladding-pumped, Yb-free, Er-doped fiber laser. We believe this is the first reported resonantly cladding-pumped fiber-Bragg-grating-based, Er-doped, large-mode-area (LMA) fiber laser. The laser, pumped by fiber-coupled InGaAsP/InP laser diode modules at 1,532.5 nm, delivers approximately 48 W of cw output at 1,590 nm. It is believed to be the highest power ever reported from a Yb-free Er-doped LMA fiber. This fully integrated laser also has the optical-to-optical efficiency of approximately 57%, to the best of our knowledge, the highest efficiency reported for cladding-pumped unidirectionally emitting Er-doped laser.

  2. High power resonant pumping of Tm-doped fiber amplifiers in core- and cladding-pumped configurations.

    PubMed

    Creeden, Daniel; Johnson, Benjamin R; Rines, Glen A; Setzler, Scott D

    2014-11-17

    We have demonstrated ultra-high efficiency amplification in Tm-doped fiber with both core- and cladding-pumped configurations using a resonant tandem-pumping approach. These Tm-doped fiber amplifiers are pumped in-band with a 1908 nm Tm-doped fiber laser and operate at 1993 nm with >90% slope efficiency. In a core-pumped configuration, we have achieved 92.1% slope efficiency and 88.4% optical efficiency at 41 W output power. In a cladding-pumped configuration, we have achieved 123.1 W of output power with 90.4% optical efficiency and a 91.6% slope efficiency. We believe these are the highest optical efficiencies achieved in a Tm-doped fiber amplifier operating in the 2-micron spectral region.

  3. 2 kW pump-light-stripper-free distributed side-coupled cladding-pumped fiber oscillator

    NASA Astrophysics Data System (ADS)

    Ying, Hanyuan; Yu, Yu; Cao, Jianqiu; Huang, Zhihe; Pan, Zhiyong; Wang, Zefeng; Chen, Jinbao

    2017-06-01

    A 2 kW pump-light-stripper-free all-fiber distributed-pumping oscillator fabricated with the distributed side-coupled cladding-pumped Yb-doped fiber is demonstrated for the first time, to the best of our knowledge. An output power of 1969 W with a slope efficiency of 72.2% is obtained. By utilizing the final-section counter-pumping scheme, pure output spectra free from residual pump light are obtained without using any pump light stripper, which demonstrates that the pump light stripper is not indispensable for this configuration. Besides, no stimulated Raman scattering component is observed in the output spectra. The laser has the M 2 factor ranging from 2.0 to 2.6. We believe that the pertinent results are helpful and valuable for designing high-power fiber laser systems.

  4. High-power continuous-wave cladding-pumped Raman fiber laser.

    PubMed

    Codemard, C A; Dupriez, P; Jeong, Y; Sahu, J K; Ibsen, M; Nilsson, J

    2006-08-01

    We demonstrate a high-power single-mode cladding-pumped Raman fiber laser. The Raman fiber laser consists of a 1.2 km long germanium-doped double-clad fiber in a linear cavity, which is spliced to a single-mode fiber. The laser is end pumped by a multimode erbium-ytterbium-doped fiber, which is coupled to the inner cladding of the Raman fiber. The embedded core was designed to be single mode at the Raman Stokes wavelength, and up to 10 W of power was obtained at 1660 nm from the single-mode fiber end. The laser has a slope efficiency of 67% and a threshold of 6.5 W.

  5. Solid-Core Photonic Bandgap Fibers for Cladding-Pumped Raman Amplification

    DTIC Science & Technology

    2011-06-03

    doped fiber laser with true single-mode output using W-type structure,” in Conference on Lasers and Electro-Optics, (Optical Society of America, 2006...stability of the fundamental mode in such large cores. Raman fiber amplifiers (RFA), in contrast, do not require doped cores. While core- pumped Raman...Stokes wavelength can enable power scaling of cladding- pumped Raman fiber lasers and amplifiers as proposed previously [8]. General considerations of

  6. 20 W continuous-wave cladding-pumped Nd-doped fiber laser at 910 nm.

    PubMed

    Laroche, M; Cadier, B; Gilles, H; Girard, S; Lablonde, L; Robin, T

    2013-08-15

    We demonstrate a double-clad fiber laser operating at 910 nm with a record power of 20 W. Laser emission on the three-level scheme is enabled by the combination of a small inner cladding-to-core diameter ratio and a high brightness pump source at 808 nm. A laser conversion efficiency as high as 44% was achieved in CW operating regime by using resonant fiber Bragg reflectors at 910 nm that prevent the lasing at the 1060 nm competing wavelength. Furthermore, in a master oscillator power-amplifier scheme, an amplified power of 14.8 W was achieved at 914 nm in the same fiber.

  7. Efficient skew-angle cladding-pumped tunable narrow-linewidth Yb-doped fiber laser.

    PubMed

    Jelger, Pär; Laurell, Fredrik

    2007-12-15

    A skew-angle cladding-pumped tunable Yb-doped fiber laser is presented. The laser was tunable over more than 30 nm, from 1022 to 1055 nm, by employing a volume Bragg grating in a retroreflector configuration as one of the cavity delimiters. Output powers in excess of 4.3 W were recorded with a spectral bandwidth of 5 GHz and an M(2) value below 1.3 over the whole tuning range.

  8. High-power and highly efficient diode-cladding-pumped Ho3+-doped silica fiber lasers.

    PubMed

    Jackson, Stuart D; Bugge, Frank; Erbert, Götz

    2007-11-15

    We demonstrate high-power operation from a singly Ho3+-doped silica fiber laser that is cladding pumped directly with diode lasers operating at 1150 nm. Internal slope efficiencies approaching the Stokes limit were produced, and the maximum output power was 2.2W. This result was achieved using a low Ho3+-ion concentration and La3+-ion codoping, which together limit the transfer of energy between excited Ho3+ ions.

  9. Cladding-pumped ytterbium-doped fiber laser with radially polarized output.

    PubMed

    Lin, Di; Daniel, J M O; Gecevičius, M; Beresna, M; Kazansky, P G; Clarkson, W A

    2014-09-15

    A simple technique for directly generating a radially polarized output beam from a cladding-pumped ytterbium-doped fiber laser is reported. Our approach is based on the use of a nanograting spatially variant waveplate as an intracavity polarization-controlling element. The laser yielded ~32 W of output power (limited by available pump power) with a radially polarized TM (01)-mode output beam at 1040 nm with a corresponding slope efficiency of 66% and a polarization purity of 95%. The beam-propagation factor (M(2)) was measured to be ~1.9-2.1.

  10. Enhancement of pump absorption efficiency by bending and twisting of double clad rare earth doped fibers (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Koška, Pavel; Peterka, Pavel; Doya, Valérie; Aubrecht, Jan; Kasik, Ivan; Podrazký, Ondřej

    2017-05-01

    High-power operation of fiber lasers was enabled by the invention of cladding-pumping in a double-clad fiber structure. Because of existence of so called skew rays in the inner clad of the fiber, pump absorption saturates along the fiber and pumping becomes inefficient. First studies of pump absorption efficiency enhancement were focused on fibers with broken circular symmetry of inner cladding eliminating skew rays [1,2]. Later, techniques of unconventional fiber coiling were proposed [3]. However, theoretical studies were limited to the assumption of a straight fiber. Even recently, the rigorous model accounting for fiber bending and twisting was described [4-6]. It was found that bending of the fiber influences modal spectra of the pump radiation and twisting provides quite efficient mode-scrambling. These effects in a synergic manner significantly enhances pump absorption rate in double clad fibers and improves laser system efficiency. In our contribution we review results of numerical modelling of pump absorption in various types of double-clad fibers, e.g., with cross section shape of hexagon, stadium, and circle; two-fiber bundle (so-called GTWave fiber structure) a panda fibers are also analyzed. We investigate pump field modal spectra evolution in hexagonally shaped fiber in straight, bended, and simultaneously bended and twisted fiber which brings new quality to understanding of the mode-scrambling and pump absorption enhancement. Finally, we evaluate the impact of enhanced pump absorption on signal gain in the fiber. These results can have practical impact in construction of fiber lasers: with pump absorption efficiency optimized by our new model (the other models did not take into account fiber twist), the double-clad fiber of shorter length can be used in the fiber lasers and amplifiers. In such a way the harmful influence of background losses and nonlinear effects can be minimized. [1] Doya, V., Legrand, O., Mortessagne, F., "Optimized absorption in a

  11. Ray trace algorithm description for the study of pump power absorption in double clad fibers

    NASA Astrophysics Data System (ADS)

    Narro, R.; Rodriguez, E.; Ponce, L.; de Posada, E.; Flores, T.; Arronte, M.

    2011-09-01

    An algorithm for the analysis of the double clad fiber design is presented. The algorithm developed in the MATLAB computing language, is based on ray tracing method applied to three-dimensional graphics figures which are composed of a set of plans. The algorithm can evaluate thousands of ray paths in sequence and its corresponding pump absorption in each of the elements of the fiber according to the Lambert-Beer law. The beam path is evaluated in 3 dimensions considering the losses by reflexion and refraction in the faces and within the fiber. Due to its flexibility, the algorithm can be used to study the ray propagation in single mode or multimode fibers, bending effects in fibers, variable geometries of the inner clad and the core, and could also be used to study tappers.

  12. Volume Bragg grating narrowed high-power and highly efficient cladding-pumped Raman fiber laser.

    PubMed

    Liu, Jun; Yao, Weichao; Zhao, Chujun; Shen, Deyuan; Fan, Dianyuan

    2014-12-10

    High-power and highly efficient operation of a single-mode cladding-pumped Raman fiber laser with narrow lasing bandwidth is demonstrated. The spectral narrowing was realized by an external cavity containing a volume Bragg grating with a center wavelength of 1658 nm. A maximum output power of 10.4 W at 1658.3 nm with a spectral linewidth (FWHM) of ∼0.1  nm was obtained for the launched pump power of 18.4 W, corresponding to a slope efficiency of 109% with respect to the launched pump power. Lasing characteristics of free-running operation are also evaluated and discussed.

  13. Modal-field spectra analysis of pump absorption efficiency in double-clad rare-earth doped fibers (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Koška, Pavel; Doya, Valérie; Peterka, Pavel

    2017-03-01

    High-power fiber lasers became important devices in many industrial and health care fields. The key for high-power operation of fiber lasers is the double-clad fiber technology transforming lower-brightness pumps into high-brightness laser beams. Efficient pump absorption in the active core of the double-clad fiber is crucial for reliable and economic operation of high power fiber lasers. In our recent work we extensively studied the dependence of the pump absorption efficiency on bending and twisting of the fiber. For the first time we theoretically predicted and later experimentally demonstrated significant enhancement of pump absorption efficiency by simultaneous bending and twisting of the double-clad fiber. In this contribution we provide extension of our previous theoretical studies using beam propagation model incorporating laser rate equations. The effect of bending and twisting on signal amplification in the double-clad fiber is analyzed for different input signal powers, and moreover, pump field modal spectra are evaluated. The results show that in correspondence with pump absorption efficiency the gain of the amplifier is enhanced under the conditions of simultaneously bent and twisted fiber. The key to understand the effect of bending and twisting on pump absorption efficiency consists in modal spectra of pump field propagating in the first clad of the double clad fiber. Three cases of straight, bent only, and simultaneously bent and twisted fiber are compared. The comparison shows that bending causes increase of the spectral range of propagating modes, but does not bring about mode-mixing. Substantial mode-mixing is established only in simultaneously bent and twisted fiber.

  14. Pump absorption and temperature distribution in erbium-doped double-clad fluoride-glass fibers.

    PubMed

    Gorjan, Martin; Marincek, Marko; Copic, Martin

    2009-10-26

    We investigate diode pump absorption and temperature distribution in three erbium-doped double-clad fluoride fibers. Absorption is measured via fluorescence intensity and temperature distribution is measured with thermal imaging. Ray-tracing calculations of absorption and heat-equation modeling of temperature distribution are also conducted. We found excellent agreement between measurements and calculations for all fibers. Results indicate that erbium-doped fluoride fiber lasers have already reached maximum output powers allowed under natural convection cooling, with fiber end being the most critical. We propose cooling and fiber design optimizations that may allow an order-of-magnitude further power-scaling.

  15. LD-pumped double-clad fiber single-frequency power amplifier

    NASA Astrophysics Data System (ADS)

    Sun, Wen-Feng; Yang, Su-Hui; Zhao, Chang-Ming

    2005-12-01

    Single frequency, single mode laser output from a monolithic resonator was amplified by a double-clad D-shape fiber of 4.4 meters long. When the signal laser is 200mw, up to 6.65 W single frequency laser output was obtained, slope efficiency is 30.6%. The amplifier is Yb 3+ doped glass fiber pumped by a laser diode array at 976nm with signal at 1064nm. Single frequency amplification has been proved by a Fabri-Parrot interferometer. It is shown from the experiments that the signal input has not been saturated. By increasing the input signal, amplification can be increased further under the same pumping power. Experimental results meet well with theoretical calculation.

  16. Resonantly cladding-pumped Yb-free Er-doped LMA fiber laser with record high power and efficiency.

    PubMed

    Zhang, Jun; Fromzel, Viktor; Dubinskii, Mark

    2011-03-14

    We report the results of our power scaling experiments with resonantly cladding-pumped Er-doped eye-safe large mode area (LMA) fiber laser. While using commercial off-the-shelf LMA fiber we achieved over 88 W of continuous-wave (CW) single transverse mode power at ~1590 nm while pumping at 1532.5 nm. Maximum observed optical-to-optical efficiency was 69%. This result presents, to the best of our knowledge, the highest power reported from resonantly-pumped Yb-free Er-doped LMA fiber laser, as well as the highest efficiency ever reported for any cladding-pumped Er-doped laser, either Yb-co-doped or Yb-free.

  17. Apparatus and method for enabling quantum-defect-limited conversion efficiency in cladding-pumped Raman fiber lasers

    DOEpatents

    Heebner, John E.; Sridharan, Arun K.; Dawson, Jay Walter; Messerly, Michael J.; Pax, Paul H.

    2016-09-20

    Cladding-pumped Raman fiber lasers and amplifiers provide high-efficiency conversion efficiency at high brightness enhancement. Differential loss is applied to both single-pass configurations appropriate for pulsed amplification and laser oscillator configurations applied to high average power cw source generation.

  18. Efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser.

    PubMed

    Wang, P; Cooper, L J; Sahu, J K; Clarkson, W A

    2006-01-15

    A novel approach to achieving robust single-spatial-mode operation of cladding-pumped fiber lasers with multimode cores is reported. The approach is based on the use of a fiber geometry in which the core has a helical trajectory within the inner cladding to suppress laser oscillation on higher-order modes. In a preliminary proof-of-principle study, efficient single-mode operation of a cladding-pumped ytterbium-doped helical-core fiber laser with a 30 microm diameter core and a numerical aperture of 0.087 has been demonstrated. The laser yielded 60.4 W of output at 1043 nm in a beam with M2 < 1.4 for 92.6 W launched pump power from a diode stack at 976 nm. The slope efficiency at pump powers well above threshold was approximately 84%, which compares favorably with the slope efficiencies achievable with conventional straight-core Yb-doped double-clad fiber lasers.

  19. LD-cladding-pumped 50 pm linewidth Tm 3+ -doped silica fiber laser.

    PubMed

    Yunjun, Zhang; Baoquan, Yao; Youlun, Ju; Hui, Zhou; Yuezhu, Wang

    2008-05-26

    We report on a Tm(3+)-doped fiber laser source operating at 1936.4 nm with a very narrow linewidth (50 pm) laser output. Up to 2.4 W cw laser power was obtained from an 82 cm long Tm(3+)-doped multimode-core fiber cladding pumped by a 792 nm laser diode (LD). The fiber laser cavity included a high-reflective dichroic and a low-reflective FBG output coupler. The multimode fiber Bragg grating (FBG) transmission spectrum and output laser spectrum were measured. By adjusting the distance between the dichroic and the Tm(3+)-doped fiber end, the multipeak laser spectrum changed to a single-peak laser spectrum.

  20. Yb-free, SLM EDFA: Comparison of 980-, 1470- and 1530-nm Excitation for the Core- and Clad-Pumping

    DTIC Science & Technology

    2008-03-01

    Er-doped 20/125 DC LMA gain fiber demonstrates laser efficiencies of 22.4% pumped at 980 nm - up to 20 W of fiber-coupled diode laser pumping. The...same LMA fiber demonstrates 33% optical-to-optical efficiency (46% slope efficiency versus absorbed power) when cladding-pumped with 1520-1530-nm...MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10 . SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY

  1. Evaluation of tantalum-alloy-clad uranium mononitride fuel specimens from 7500-hour, 1040 C pumped-lithium-loop test

    NASA Technical Reports Server (NTRS)

    Watson, G. K.

    1974-01-01

    Simulated nuclear fuel element specimens, consisting of uranium mononitride (UN) fuel cylinders clad with tungsten-lined T-111, were exposed for up to 7500 hr at 1040 C (1900 F) in a pumped-lithium loop. The lithium flow velocity was 1.5 m/sec (5 ft/sec) in the specimen test section. No evidence of any compatibility problems between the specimens and the flowing lithium was found based on appearance, weight change, chemistry, and metallography. Direct exposure of the UN to the lithium through a simulated cladding crack resulted in some erosion of the UN in the area of the defect. The T-111 cladding was ductile after lithium exposure, but it was sensitive to hydrogen embrittlement during post-test handling.

  2. Generation of watt-level single-longitudinal-mode output from cladding-pumped short fiber lasers.

    PubMed

    Qiu, T; Suzuki, S; Schülzgen, A; Li, L; Polynkin, A; Temyanko, V; Moloney, J V; Peyghambarian, N

    2005-10-15

    We generate as much as 1.6 W of continuous-wave 1550 nm single-longitudinal-mode output from a cladding pumped Er-Yb codoped phosphate fiber laser. This power is to our knowledge among the highest in single-longitudinal-mode fiber lasers. The narrowband fiber Bragg grating output coupler is demonstrated to be an effective element for providing the single-longitudinal-mode selection.

  3. FUNDAMENTAL AREAS OF PHENOMENOLOGY (INCLUDING APPLICATIONS): Ld-Clad-Pumped All-Fiber Tm3+-Doped Silica Fiber Laser

    NASA Astrophysics Data System (ADS)

    Zhang, Yun-Jun; Song, Shi-Fei; Tian, Yi; Wang, Yue-Zhu

    2009-08-01

    The CW 39.4 W all-fiber LD-clad-pumped Tm3+-doped fiber laser output is reported with a slope efficiency of 34% in respect to the pump power. The all-fiber laser is made up by progressively splicing the pigtail fiber, matched FBG fiber and Tm-doped fiber. The reflective FBG and Tm-doped fiber end fresnel reflection build up the laser resonance cavity. Due to the multi-mode FBG as the reflective mirror, the output laser spectrum is multi-peaks at high power output, whereas the total spectrum width is less than 2nm at nearly 1.94 μm.

  4. Stabilization and power scaling of cladding pumped Er:Yb-codoped fiber amplifier via auxiliary signal at 1064 nm.

    PubMed

    Kuhn, Vincent; Wessels, Peter; Neumann, Jörg; Kracht, Dietmar

    2009-09-28

    To the best of our knowledge we report for the first time on an Yb-sensitized Er-doped cladding pumped fiber amplifier which is simultaneously seeded by two single-frequency lasers operating at 1556 nm and 1064 nm, respectively. This mode of operation ensures stable amplifier operation by reducing the gain around 1 microm wavelength to the large signal gain value, while having no significant effect on the slope efficiency of the amplification process at 1556 nm when pumping at 976 nm. We were able to demonstrate stable output power of 8.7 W at 1556 nm with an amplifier gain of > 22 dB, a co-propagating pumping scheme and the power limitation only being set by the available amount of pump power.

  5. Optimization of strongly pumped Yb-doped double-clad fiber lasers using a wide-scope approximate analytical model

    NASA Astrophysics Data System (ADS)

    Mohammed, Ziad; Saghafifar, Hossein

    2014-02-01

    An analytical model based on the rate equations of strongly pumped Yb-doped double-clad fiber laser (DCFLs) is presented. The output power and the distributed laser along the whole fiber have been found. In this paper, most parameters affecting the laser performance have been considered. The influences of scattering losses, pump reflection, output reflectivity, doping concentration and fiber length have been studied. It is shown that for wide ranges of the previous parameters and large variations of the input powers for all types of pumping (forward, backward and two-end), the maximum relative error of the output power would be less than 2.72% when the results are compared with the numerical model. Depending on our analytical model, a simple optimization method has been illustrated for high-power laser oscillators.

  6. Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications

    NASA Astrophysics Data System (ADS)

    Chen, H.; Jin, C.; Huang, B.; Fontaine, N. K.; Ryf, R.; Shang, K.; Grégoire, N.; Morency, S.; Essiambre, R.-J.; Li, G.; Messaddeq, Y.; Larochelle, S.

    2016-08-01

    Space-division multiplexing (SDM), whereby multiple spatial channels in multimode and multicore optical fibres are used to increase the total transmission capacity per fibre, is being investigated to avert a data capacity crunch and reduce the cost per transmitted bit. With the number of channels employed in SDM transmission experiments continuing to rise, there is a requirement for integrated SDM components that are scalable. Here, we demonstrate a cladding-pumped SDM erbium-doped fibre amplifier (EDFA) that consists of six uncoupled multimode erbium-doped cores. Each core supports three spatial modes, which enables the EDFA to amplify a total of 18 spatial channels (six cores × three modes) simultaneously with a single pump diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and <7 dB noise figure over the C-band. This cladding-pumped EDFA enables combined space-division and wavelength-division multiplexed transmission over multiple multimode fibre spans.

  7. Theoretical and numerical treatment of modal instability in high-power core and cladding-pumped Raman fiber amplifiers.

    PubMed

    Naderi, Shadi; Dajani, Iyad; Grosek, Jacob; Madden, Timothy

    2016-07-25

    Raman fiber lasers have been proposed as potential candidates for scaling beyond the power limitations imposed on near diffraction-limited rare-earth doped fiber lasers. One limitation is the modal instability (MI) and we explore the physics of this phenomenon in Raman fiber amplifiers (RFAs). By utilizing the conservation of number of photons and conservation of energy in the absence of loss, the 3 × 3 governing system of nonlinear equations describing the pump and the signal modal content are decoupled and solved analytically for cladding-pumped RFAs. By comparing the extracted signal at MI threshold for the same step index-fiber, it is found that the MI threshold is independent of the length of the amplifier or whether the amplifier is co-pumped or counter-pumped; dictated by the integrated heat load along the length of fiber. We extend our treatment to gain-tailored RFAs and show that this approach is of limited utility in suppressing MI. Finally, we formulate the physics of MI in core-pumped RFAs where both pump and signal interferences participate in writing the time-dependent index of refraction grating.

  8. 75 W 40% efficiency single-mode all-fiber erbium-doped laser cladding pumped at 976 nm.

    PubMed

    Kotov, L V; Likhachev, M E; Bubnov, M M; Medvedkov, O I; Yashkov, M V; Guryanov, A N; Lhermite, J; Février, S; Cormier, E

    2013-07-01

    Optimization of Yb-free Er-doped fiber for lasers and amplifiers cladding pumped at 976 nm was performed in this Letter. The single-mode fiber design includes an increased core diameter of 34 μm and properly chosen erbium and co-dopant concentrations. We demonstrate an all-fiber high power laser and power amplifier based on this fiber with the record slope efficiency of 40%. To the best of our knowledge, the achieved output power of 75 W is the highest power reported for such lasers.

  9. Self-pulsing in a large mode area, end-pumped, double-clad ytterbium-doped fiber laser

    NASA Astrophysics Data System (ADS)

    Toral-Acosta, D.; Martinez-Rios, A.; Selvas-Aguilar, R.; Kir'yanov, A. V.; Anzueto-Sanchez, G.; Duran-Ramirez, V. M.

    2014-10-01

    The characteristics of self-pulsing in a large mode area, end-pumped, double-clad Yb-doped fiber laser are presented. The laser operates in a self-pulsing regime, either by using one or two perpendicularly cleaved ends as the feedback mirrors, while it transforms in a broadband amplified spontaneous emission source when both ends are angle cleaved. In the pulsed regime, up to 2 µs full width at half maximum pulse widths and repetition rates of the order of hundreds of kHz are generated.

  10. Simulation and measurement of threshold pump powers for the stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) in ytterbium-doped double-clad CW fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Abdollahi, M.; Bagheri Harouni, M.; Hekmat, M. J.; Fakhari, M.; Shahriari, N.; Kanani, M.; Normohamadi, H.

    2016-11-01

    By considering propagation equations of Stokes-waves for different orders of the stimulated Brillouin scattering (SBS) and the stimulated Raman scattering (SRS) together with propagation-rate equations of Ytterbium-doped double-clad fiber amplifiers, we numerically analyze steady-state characteristics of these amplifiers such as Amplified Spontaneous Emission (ASE) and threshold pump power and parameters which have influence over it such as pumping configuration, pumping wavelength, input signal wavelength, input signal power, input signal bandwidth and amplifier geometry. Also in an experimental setup threshold pump powers under both forward and backward pumping configurations are measured. Our results are of prime importance for applications such as nonlinear frequency generation.

  11. Diode-Pumped Organo-Lead Halide Perovskite Lasing in a Metal-Clad Distributed Feedback Resonator.

    PubMed

    Jia, Yufei; Kerner, Ross A; Grede, Alex J; Brigeman, Alyssa N; Rand, Barry P; Giebink, Noel C

    2016-07-13

    Organic-inorganic lead halide perovskite semiconductors have recently reignited the prospect of a tunable, solution-processed diode laser, which has the potential to impact a wide range of optoelectronic applications. Here, we demonstrate a metal-clad, second-order distributed feedback methylammonium lead iodide perovskite laser that marks a significant step toward this goal. Optically pumping this device with an InGaN diode laser at low temperature, we achieve lasing above a threshold pump intensity of 5 kW/cm(2) for durations up to ∼25 ns at repetition rates exceeding 2 MHz. We show that the lasing duration is not limited by thermal runaway and propose instead that lasing ceases under continuous pumping due to a photoinduced structural change in the perovskite that reduces the gain on a submicrosecond time scale. Our results indicate that the architecture demonstrated here could provide the foundation for electrically pumped lasing with a threshold current density Jth < 5 kA/cm(2) under sub-20 ns pulsed drive.

  12. Tm3+ cladding-doped fiber for selective wavelength filtering in high-power pump lasers.

    PubMed

    Davis, Monica K; Dejneka, Matthew J; Ainslie, Jim

    2004-04-01

    Scattering and reflection of transmission band power in a fiber amplifier cause increased bit-error rates through multiple path interference (MPI). We report a passive method for reducing MPI contributions from the front facet of a 980-nm fiber-Bragg-grating-stabilized pump laser by use of a Tm3+-doped fiber pigtail between the diode facet and the fiber Bragg grating. Optical return loss in the C band is reduced to below -30 dB.

  13. High-power and highly efficient diode-cladding-pumped holmium-doped fluoride fiber laser operating at 2.94 microm.

    PubMed

    Jackson, Stuart D

    2009-08-01

    A high-power diode-cladding-pumped Ho(3+), Pr(3+)-doped fluoride glass fiber laser is demonstrated. The laser produced a maximum output power of 2.5 W at a slope efficiency of 32% using diode lasers emitting at 1,150 nm. The long-emission wavelength of 2.94 microm measured at maximum pump power, which is particularly suited to medical applications, indicates that tailoring of the proportion of Pr(3+) ions can provide specific emission wavelengths while providing sufficient de-excitation of the lower laser level.

  14. High-power linearly-polarized operation of a cladding-pumped Yb fibre laser using a volume Bragg grating for wavelength selection.

    PubMed

    Jelger, P; Wang, P; Sahu, J K; Laurell, F; Clarkson, W A

    2008-06-23

    In this work a volume Bragg grating is used as a wavelength selective element in a high-power cladding-pumped Yb-doped silica fiber laser. The laser produced 138 W of linearly-polarized single-spatial-mode output at 1066 nm with a relatively narrow linewidth of 0.2 nm for approximately 202 W of launched pump power at 976 nm. The beam propagation factor (M(2)) for the output beam was determined to be 1.07. Thermal limitations of volume Bragg gratings are discussed in the context of power scaling for fiber lasers.

  15. The all-fiber cladding-pumped Yb-doped gain-switched laser.

    PubMed

    Larsen, C; Hansen, K P; Mattsson, K E; Bang, O

    2014-01-27

    Gain-switching is an alternative pulsing technique of fiber lasers, which is power scalable and has a low complexity. From a linear stability analysis of rate equations the relaxation oscillation period is derived and from it, the pulse duration is defined. Good agreement between the measured pulse duration and the theoretical prediction is found over a wide range of parameters. In particular we investigate the influence of an often present length of passive fiber in the cavity and show that it introduces a finite minimum in the achievable pulse duration. This minimum pulse duration is shown to occur at longer active fibers length with increased passive length of fiber in the cavity. The peak power is observed to depend linearly on the absorbed pump power and be independent of the passive fiber length. Given these conclusions, the pulse energy, duration, and peak power can be estimated with good precision.

  16. High-efficiency ytterbium-free erbium-doped all-glass double cladding silicate glass fiber for resonantly-pumped fiber lasers.

    PubMed

    Qiang, Zexuan; Geng, Jihong; Luo, Tao; Zhang, Jun; Jiang, Shibin

    2014-02-01

    A highly efficient ytterbium-free erbium-doped silicate glass fiber has been developed for high-power fiber laser applications at an eye-safe wavelength near 1.55 μm. Our preliminary experiments show that high laser efficiency can be obtained from a relatively short length of the gain fiber when resonantly pumped at 1535 nm in both core- and cladding-pumping configurations. With a core-pumping configuration as high as 75%, optical-to-optical efficiency and 4 W output power were obtained at 1560 nm from a 1 m long gain fiber. When using a cladding-pumping configuration, approximately 13 W output power with 67.7% slope efficiency was demonstrated from a piece of 2 m long fiber. The lengths of silicate-based gain fiber are much shorter than their silica-based counterparts used in other experiments, which is significantly important for high-power narrow-band and/or pulsed laser applications.

  17. Laser emission from diode-pumped Nd:YAG cladding waveguides obtained by direct writing with a femtosecond-laser beam

    NASA Astrophysics Data System (ADS)

    Salamu, Gabriela; Voicu, Flavius; Jipa, Florin; Zamfirescu, Marian; Dascalu, Traian; Pavel, Nicolaie

    2014-05-01

    Cladding waveguides have been realized in Nd:YAG by direct writing with a femtosecond-laser beam. A classical method that inscribes many tracks around the waveguide circumference with step-by-step translations of the laser medium, and a new technique in which the laser medium is moved on a helical trajectory and that delivers waveguides with well-defined walls were employed. Laser emission on the 1.06 μm 4F3/2-->4I11/2 transition and at 1.3 μm on the 4F3/2-->4I13/2 line was obtained under the pump with a fiber-coupled diode laser. Thus, laser pulses at 1.06 μm with energy of 1.3 mJ for the pump at 807 nm with pulses of 12.5-mJ energy were recorded from a circular waveguide of 100-μm diameter that was inscribed in a 5-mm long, 0.7-at.% Nd:YAG single crystal by the classical translation technique. A similar waveguide that was realized in a 5-mm long, 1.1-at.% Nd:YAG ceramic increased the 1.06-μm laser pulse energy to 2.15 mJ for the pump pulses of 13.1-mJ energy. Furthermore, a circular waveguide of 100-μm diameter that was inscribed in the Nd:YAG ceramic by the helical-movement method yielded pulses at 1.06 μm with increased maximum energy of 3.2 mJ; the overall optical-to-optical efficiency was 0.24, and the laser operated with a slope efficiency of 0.29. The same device outputted laser pulses at 1.3 μm with energy of 1.15 mJ.

  18. Efficient operation of double-clad Yb3+-doped fiber lasers with a novel circular cladding geometry.

    PubMed

    Martínez-Rios, A; Starodumov, A N; Po, H; Wang, Y; Demidov, A A; Li, X

    2003-09-15

    A highly efficient double-clad Yb3+-doped fiber laser with a novel cladding geometry is described. A round double-clad fiber with a small D-shaped hole for breaking a circular symmetry in a cladding combines the advantages of ease of manufacture and handling round fibers with efficient absorption of pump light. Fiber lasers with a double-D cladding shape and a D-hole cladding are compared. We report what are to our knowledge the highest slope efficiencies of 73% and 69%, respectively, pumping at 915 nm. Output powers in excess of 13 W are demonstrated.

  19. Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system

    NASA Astrophysics Data System (ADS)

    Ji, En-Cai; Liu, Qiang; Hu, Zhen-Yue; Gong, Ma-Li

    2015-10-01

    The steady-state gain distribution in cladding pumped thulium-doped fiber laser (TDFL) is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition (OFI) and always occurs in tandem TDFL-Ho:YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho:YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method. Project supported by the National Natural Science Foundation of China (Grant No. 61275146), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120002110066), and the Special Program of the Co-construction with Beijing Municipal Government of China (Grant No. 20121000302).

  20. High power cladding light strippers

    NASA Astrophysics Data System (ADS)

    Wetter, Alexandre; Faucher, Mathieu; Sévigny, Benoit

    2008-02-01

    The ability to strip cladding light from double clad fiber (DCF) fibers is required for many different reasons, one example is to strip unwanted cladding light in fiber lasers and amplifiers. When removing residual pump light for example, this light is characterized by a large numerical aperture distribution and can reach power levels into the hundreds of watts. By locally changing the numerical aperture (N.A.) of the light to be stripped, it is possible to achieve significant attenuation even for the low N.A. rays such as escaped core modes in the same device. In order to test the power-handling capability of this device, one hundred watts of pump and signal light is launched from a tapered fusedbundle (TFB) 6+1x1 combiner into a high power-cladding stripper. In this case, the fiber used in the cladding stripper and the output fiber of the TFB was a 20/400 0.06/0.46 N.A. double clad fiber. Attenuation of over 20dB in the cladding was measured without signal loss. By spreading out the heat load generated by the unwanted light that is stripped, the package remained safely below the maximum operating temperature internally and externally. This is achieved by uniformly stripping the energy along the length of the fiber within the stripper. Different adhesive and heat sinking techniques are used to achieve this uniform removal of the light. This suggests that these cladding strippers can be used to strip hundreds of watts of light in high power fiber lasers and amplifiers.

  1. Diode-laser pumping into the emitting level for efficient lasing of depressed cladding waveguides realized in Nd:YVO4 by the direct femtosecond-laser writing technique.

    PubMed

    Pavel, Nicolaie; Salamu, Gabriela; Jipa, Florin; Zamfirescu, Marian

    2014-09-22

    Depressed cladding waveguides have been realized in Nd:YVO(4) employing direct writing technique with a femtosecond-laser beam. It was shown that the output performances of such laser devices are improved by the reduction of the quantum defect between the pump wavelength and the laser wavelength. Thus, under the classical pump at 808 nm (i.e. into the (4)F(5/2) level), a 100-μm diameter circular waveguide inscribed in a 0.7-at.% Nd:YVO(4) outputted 1.06-μm laser pulses with 3.0-mJ energy, at 0.30 optical efficiency and slope efficiency of 0.32. The pump at 880 nm (i.e.directly into the (4)F(3/2) emitting level) increased the pulse energy at 3.8 mJ and improved both optical efficiency and slope efficiency at 0.36 and 0.39, respectively. The same waveguide yielded continuous-wave 1.5-W output power at 1.06 μm under the pump at 880 nm. Laser emission at 1.34 μm was also improved using the pump into the (4)F(3/2) emitting level of Nd:YVO(4).

  2. Pump

    SciTech Connect

    Johnson, J.W.; Abdul.Hye, A.B.M.

    1983-10-25

    A pump for injecting chemicals into a well employs a pivot arm for synchronous movement with a well pump. The pivot arm causes reciprocation of a plunger within the body of the chemical pump. The plunger, during its upward stroke causes the entry of chemicals from an outside source into the pump body and, during its downward stroke, causes the exiting of the chemicals into the well. (2 claims.

  3. Clad metal joint closure

    SciTech Connect

    Siebert, O.W.

    1985-04-09

    A plasma arc spray overlay of cladding metals is used over joints between clad metal pieces to provide a continuous cladding metal surface. The technique permits applying an overlay of a high melting point cladding metal to a cladding metal surface without excessive heating of the backing metal.

  4. PUMPS

    DOEpatents

    Thornton, J.D.

    1959-03-24

    A pump is described for conveving liquids, particure it is not advisable he apparatus. The to be submerged in the liquid to be pumped, a conduit extending from the high-velocity nozzle of the injector,and means for applying a pulsating prcesure to the surface of the liquid in the conduit, whereby the surface oscillates between positions in the conduit. During the positive half- cycle of an applied pulse liquid is forced through the high velocity nozzle or jet of the injector and operates in the manner of the well known water injector and pumps liquid from the main intake to the outlet of the injector. During the negative half-cycle of the pulse liquid flows in reverse through the jet but no reverse pumping action takes place.

  5. Linear inner cladding fiber amplifier suppressing mode instability

    NASA Astrophysics Data System (ADS)

    Li, Zebiao; Huang, Zhihua; Lin, Honghuan; Xu, Shanhui; Yang, Zhongmin; Wang, Jianjun; Jing, Feng

    2016-11-01

    We use a semi-analytical model considering pump power saturation in high power fiber laser systems of multi-kW-class to calculate mode instability threshold. A novel designed fiber, linear inner-cladding fiber, can mitigate mode instability effect by decreasing nonlinear coupling coefficient and smoothing heat profile along the fiber. We investigate strong pump absorption of linear inner-cladding fiber, leading to shorter fiber length. With 915 nm pumping, linear inner-cladding fiber can reach 10 kW output power without mode instability in theory.

  6. Two-octave spanning single pump parametric amplification at 1550 nm in a host lead-silicate binary multi-clad microstructure fiber: Influence of multi-order dispersion engineering

    NASA Astrophysics Data System (ADS)

    Chatterjee, Sudip K.; Khan, Saba N.; Chaudhuri, Partha Roy

    2014-12-01

    An ultra-wide 1646 nm (1084-2730 nm), continuous-wave single pump parametric amplification spanning from near-infrared to short-wave infrared band (NIR-SWIR) in a host lead-silicate based binary multi-clad microstructure fiber (BMMF) is analyzed and reported. This ultra-broad band (widest reported to date) parametric amplification with gain more than 10 dB is theoretically achieved by a combination of low input pump power source ~7 W and a short-length of ~70 cm of nonlinear-BMMF through accurately engineered multi-order dispersion coefficients. A highly efficient theoretical formulation based on four-wave-mixing (FWM) is worked out to determine fiber's chromatic dispersion (D) profile which is used to optimise the gain-bandwidth and ripple of the parametric gain profile. It is seen that by appropriately controlling the higher-order dispersion coefficient (up-to sixth order), a great enhancement in the gain-bandwidth (2-3 times) can be achieved when operated very close to zero-dispersion wavelength (ZDW) in the anomalous dispersion regime. Moreover, the proposed theoretical model can predict the maximum realizable spectral width and the required pump-detuning (w.r.t ZDW) of any advanced complex microstructured fiber. Our thorough investigation of the wide variety of broadband gain spectra obtained as an integral part of this research work opens up the way for realizing amplification in the region (SWIR) located far from the pump (NIR) where good amplifiers currently do not exist.

  7. Second harmonic generation in thin optical fibers via cladding modes.

    PubMed

    Elzahaby, Eman A; Kandas, Ishac; Aly, Moustafa H

    2016-05-30

    Since silica goes under the category of amorphous materials, it is difficult to investigate important processes such as second harmonic generation (SHG) in silica-based fibers. In this paper, we proposed a method for SHG relaying on cladding modes as pump modes. Cladding modes are introduced in optical fibers through tilted long period grating (T-LPG), where power of core mode is transferred into cladding modes. By functionalizing T-LPG with nonlinear coating, the interaction occurs between cladding modes and the coating material, consequently second harmonic signal (SHS) is generated with efficiency up to 0.14%.

  8. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser

    PubMed Central

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-01-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900–2000 nm. PMID:27416893

  9. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser

    NASA Astrophysics Data System (ADS)

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-07-01

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900-2000 nm.

  10. High-power ultralong-wavelength Tm-doped silica fiber laser cladding-pumped with a random distributed feedback fiber laser.

    PubMed

    Jin, Xiaoxi; Du, Xueyuan; Wang, Xiong; Zhou, Pu; Zhang, Hanwei; Wang, Xiaolin; Liu, Zejin

    2016-07-15

    We demonstrated a high-power ultralong-wavelength Tm-doped silica fiber laser operating at 2153 nm with the output power exceeding 18 W and the slope efficiency of 25.5%. A random distributed feedback fiber laser with the center wavelength of 1173 nm was employed as pump source of Tm-doped fiber laser for the first time. No amplified spontaneous emissions or parasitic oscillations were observed when the maximum output power reached, which indicates that employing 1173 nm random distributed feedback fiber laser as pump laser is a feasible and promising scheme to achieve high-power emission of long-wavelength Tm-doped fiber laser. The output power of this Tm-doped fiber laser could be further improved by optimizing the length of active fiber, reflectivity of FBGs, increasing optical efficiency of pump laser and using better temperature management. We also compared the operation of 2153 nm Tm-doped fiber lasers pumped with 793 nm laser diodes, and the maximum output powers were limited to ~2 W by strong amplified spontaneous emission and parasitic oscillation in the range of 1900-2000 nm.

  11. The ray trace method on studying double-cladding optical fiber

    NASA Astrophysics Data System (ADS)

    Wei, Yan; Fei, Yuemu

    2005-01-01

    In this paper, the pump absorption efficiency and the optimum length of DCOFs with several kinds of inner cladding shapes have been studied through the ray trace method. The DCOFs with circular, rectangular, triangular, hexagonal inner cladding have been studied in this paper. Expect for the DCOF with circular inner cladding. The maximum pump absorption efficiency of the DCOFs above exceed 0.9. It is found that the triangle shape has the highest absorption and there is only little difference among the polygon DCOF. The ray trace method is a more simple and quick method and it is competent for DCOFs with more kinds of inner cladding.

  12. Comparison of high-power diode pumped actively Q-switched double-clad flower shape co-doped-Er3+:Yb3+fiber laser using acousto-optic and mechanical (optical) modulators

    NASA Astrophysics Data System (ADS)

    El-Sherif, Ashraf F.; Harfosh, Amr

    2015-09-01

    A diode-pumped acousto-optic Q-switching Er3+:Yb3+ co-doped high-power fiber laser is reported, laser output average power in excess of 1.65 W was achieved for Q-switching at relatively high repetition rates from 10 to 100 kHz. The shortest pulse duration obtained was 10 ns, giving a highest peak power of 9.8 kW and 98 μJ energy per pulse, this is the highest power yet reported from any type of actively Q-switched flower double-clad Er3+:Yb3+ fiber laser operating in low order mode at 1550 nm. The pulse train with high pulse-to-pulse stability of 95% occurred at a range of repetition rates up to 100 kHz with peak power of 0.4 kW, 40 ns pulse width and 16 μJ energy per pulse at 1550 nm for a launched pump power of 5 W. With the mechanical modulation Q-switching of the Er3+:Yb3+ co-doped fiber laser, it was found that the narrowest pulse width of 35 ns was obtained with peak power of 15.5 kW and energy per pulse 0.5 mJ at pulse repetition frequency of 1 kHz. A moderate pulse-to-pulse stability of 75% occurred over a range of high repetition rates. A comparison between mechanical modulation and acousto-optic Q-switching has been made at a repetition rate of 20 kHz. The energy per pulse, pulse width, and the average power of a mechanical optical Q-switching laser were greater than for the acousto-optic Q-switching, but the pulse width is narrower and so the high peak power of an acousto-optic Q-switching pulse is greater than for the mechanical (optical) Q-switching laser at repetition rates of up to 100 kHz.

  13. Dependence of Surface Contrast on Emission Angle in Cassini ISS 938-nm Images of Titan

    NASA Technical Reports Server (NTRS)

    Fussner, S.; McEwen, A.; Perry, J.; Turtle, E.; Dawson, D.; Porco, C.; West, R.

    2005-01-01

    Titan, the largest of Saturn s moons, is one of the most difficult solid surfaces in the Solar System to study. It is shrouded in a thick atmosphere with fine haze particles extending up to 500 km. [1] The atmosphere itself is rich in methane, which allows clear viewing of the surface only through narrow "windows" in the methane spectrum. Even in these methane windows, the haze absorbs and scatters light, blurring surface features and reducing the contrast of images. The haze optical depth is high at visible wavelengths, and decreases at longer (infrared) wavelengths. [2

  14. Initial Cladding Condition

    SciTech Connect

    E. Siegmann

    2000-08-22

    The purpose of this analysis is to describe the condition of commercial Zircaloy clad fuel as it is received at the Yucca Mountain Project (YMP) site. Most commercial nuclear fuel is encased in Zircaloy cladding. This analysis is developed to describe cladding degradation from the expected failure modes. This includes reactor operation impacts including incipient failures, potential degradation after reactor operation during spent fuel storage in pool and dry storage and impacts due to transportation. Degradation modes include cladding creep, and delayed hydride cracking during dry storage and transportation. Mechanical stresses from fuel handling and transportation vibrations are also included. This Analysis and Model Report (AMR) does not address any potential damage to assemblies that might occur at the YMP surface facilities. Ranges and uncertainties have been defined. This analysis will be the initial boundary condition for the analysis of cladding degradation inside the repository. In accordance with AP-2.13Q, ''Technical Product Development Planning'', a work plan (CRWMS M&O 2000c) was developed, issued, and utilized in the preparation of this document. There are constraints, caveats and limitations to this analysis. This cladding degradation analysis is based on commercial Pressurized Water Reactor (PWR) fuel with Zircaloy cladding but is applicable to Boiling Water Reactor (BWR) fuel. Reactor operating experience for both PWRs and BWRs is used to establish fuel reliability from reactor operation. It is limited to fuel exposed to normal operation and anticipated operational occurrences (i.e. events which are anticipated to occur within a reactor lifetime), and not to fuel that has been exposed to severe accidents. Fuel burnup projections have been limited to the current commercial reactor licensing environment with restrictions on fuel enrichment, oxide coating thickness and rod plenum pressures. The information provided in this analysis will be used in

  15. Temperature limits for LMFBR fuel cladding under upset and emergency operating conditions

    SciTech Connect

    Govindarajan, S.; Chetal, S.C.

    1996-07-01

    LMFBR fuel pin cladding tube is subjected to high transient temperatures during incidents such as pump trip, pump to grid plate pipe rupture etc. It is required to know temperature limits under such transient operating conditions for components involved while analyzing such incidents. A methodology for deriving such limits for fuel clad tube is worked out in this paper by making use of the transient damage correlation proposed by W.F. Brizes et. al.

  16. EPRI fuel cladding integrity program

    SciTech Connect

    Yang, R.

    1997-01-01

    The objectives of the EPRI fuel program is to supplement the fuel vendor research to assure that utility economic and operational interests are met. To accomplish such objectives, EPRI has conducted research and development efforts to (1) reduce fuel failure rates and mitigate the impact of fuel failures on plant operation, (2) provide technology to extend burnup and reduce fuel cycle cost. The scope of R&D includes fuel and cladding. In this paper, only R&D related to cladding integrity will be covered. Specific areas aimed at improving fuel cladding integrity include: (1) Fuel Reliability Data Base; (2) Operational Guidance for Defective Fuel; (3) Impact of Water Chemistry on Cladding Integrity; (4) Cladding Corrosion Data and Model; (5) Cladding Mechanical Properties; and (6) Transient Fuel Cladding Response.

  17. Random fiber laser directly pumped by a high-power laser diode.

    PubMed

    Babin, S A; Dontsova, E I; Kablukov, S I

    2013-09-01

    A random lasing based on Rayleigh scattering (RS) in a passive fiber directly pumped by a high-power laser diode (LD) has been demonstrated. Owing to the RS-based random distributed feedback (RDFB) the low-quality LD beam (938 nm) is converted into the high-quality laser output (980 nm). Because of the relatively low excess above the threshold with the available LD, the RDFB laser output is not stationary and limited in power at the 0.5 W level. In the used gradient-index fiber, the output beam has 4.5 lower divergence as compared with the pump beam thus demonstrating a new way for development of high-power fiber lasers with high-quality output.

  18. Fuel pin cladding

    DOEpatents

    Vaidyanathan, S.; Adamson, M.G.

    1983-12-16

    An improved fuel pin cladding, particularly adapted for use in breeder reactors, is described which consist of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel an/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

  19. Fuel pin cladding

    DOEpatents

    Vaidyanathan, S.; Adamson, M.G.

    1986-01-28

    Disclosed is an improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients. 2 figs.

  20. Fuel pin cladding

    DOEpatents

    Vaidyanathan, Swaminathan; Adamson, Martyn G.

    1986-01-01

    An improved fuel pin cladding, particularly adapted for use in breeder reactors, consisting of composite tubing with austenitic steel on the outer portion of the thickness of the tube wall and with nickel and/or ferritic material on the inner portion of the thickness of the tube wall. The nickel forms a sacrificial barrier as it reacts with certain fission products thereby reducing fission product activity at the austenitic steel interface. The ferritic material forms a preventive barrier for the austenitic steel as it is immune to liquid metal embrittlement. The improved cladding permits the use of high density fuel which in turn leads to a better breeding ratio in breeder reactors, and will increase the threshold at which failure occurs during temperature transients.

  1. Design of intrinsically single-mode double clad crystalline fiber waveguides for high power lasers

    NASA Astrophysics Data System (ADS)

    Li, Da; Hong, Pengda; Meissner, Stephanie K.; Meissner, Helmuth E.

    2016-03-01

    Recently, double-clad crystalline fiber waveguides (CFWs), consisting of single crystalline or ceramic RE3+:YAG cores of square cross section and inner claddings of either undoped or laser-inactive-ion-doped YAG and outer claddings of sapphire, have been successfully demonstrated. These waveguides, manufactured by an Adhesive-Free Bonding (AFB®) technique, can be precisely engineered and fabricated with predictable beam propagation behavior. In this work, with high power laser designs in mind, minimum thicknesses for inner cladding are derived for different core cross sections and refractive index differences between the core and inner cladding and sapphire as outer cladding material for common laser core dopants such as Nd3+, Yb3+, Er3+, Tm3+ and Ho3+. All designs are intended to use high NA high power laser diode pumping to obtain high power intrinsically single transverse mode laser output. The obtained data are applicable to any crystalline fiber waveguide design, regardless of fabrication technique. As an example, a CFW with 40 μm × 40 μm 4% Tm:YAG core, 5% Yb:YAG inner cladding, and sapphire outer cladding was calculated to be intrinsically single transverse mode, with the minimum inner cladding width of 21.7 μm determined by the effective index technique [1].

  2. Pump and Signal Taper for Airclad Fibers

    DTIC Science & Technology

    2006-01-05

    as follows: Crystal Fibre A/S will develop a taper/coupler solution to interface between a new polarization maintaining/polarizing amplifier fiber ...MM) pump combiner with a high NA air-clad output. The input side of the combiner is 7 individual MM pump delivery solid all- glass fibers . The NA of...pump combiner. MOTIVATION FINAL REPORT ITEM 0002 In a typical standard fused fiber coupler a number of all- glass 0.22 NA pump

  3. Aerogel-clad optical fiber

    DOEpatents

    Sprehn, G.A.; Hrubesh, L.W.; Poco, J.F.; Sandler, P.H.

    1997-11-04

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency. 4 figs.

  4. Aerogel-clad optical fiber

    DOEpatents

    Sprehn, Gregory A.; Hrubesh, Lawrence W.; Poco, John F.; Sandler, Pamela H.

    1997-01-01

    An optical fiber is surrounded by an aerogel cladding. For a low density aerogel, the index of refraction of the aerogel is close to that of air, which provides a high numerical aperture to the optical fiber. Due to the high numerical aperture, the aerogel clad optical fiber has improved light collection efficiency.

  5. Oxidation resistant claddings for superalloys.

    NASA Technical Reports Server (NTRS)

    Gedwill, M. A.; Grisaffe, S. J.

    1971-01-01

    The oxidation protection afforded IN-100 and WI-52 superalloys by thin claddings of NiCrAlSi and FeCrAlY alloys was examined primarily at 1090 C. Comparisons were made with commercial aluminide coatings using cyclic furnace and high velocity burner rig tests. In furnace tests, NiCrAlSi on IN-100 and FeCrAlY on WI-52 performed as well or better than two aluminide coatings. Burner rig performance of the FeCrAlY cladding was better than that of the NiCrAlSi cladding on IN-100 and the aluminide coating on WI-52, but less than the aluminide coating on IN-100. An aluminized NiCrAlSi cladding performed better than any coating or cladding.

  6. Oxidation resistant claddings for superalloys.

    NASA Technical Reports Server (NTRS)

    Gedwill, M. A.; Grisaffe, S. J.

    1972-01-01

    The oxidation protection afforded IN-100 and WI-52 superalloys by thin claddings of NiCrAlSi and FeCrAlY alloys was examined primarily at 1090 C. Comparisons were made with commercial aluminide coatings, using cyclic furnace and high-velocity burner rig tests. In furnace tests, NiCrAlSi on IN-100 and FeCrAlY on WI-52 performed as well as or better than two aluminide coatings. Burner rig performance of the FeCrAlY cladding was better than that of the NiCrAlSi cladding on IN-100 and the aluminide coating on WI-52, but less than the aluminide coating on IN-100. An aluminized NiCrAlSi cladding performed better than any coating or cladding.

  7. Transverse pumped laser amplifier architecture

    DOEpatents

    Bayramian, Andrew James; Manes, Kenneth R.; Deri, Robert; Erlandson, Alvin; Caird, John; Spaeth, Mary L.

    2015-05-19

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  8. Transverse pumped laser amplifier architecture

    DOEpatents

    Bayramian, Andrew James; Manes, Kenneth; Deri, Robert; Erlandson, Al; Caird, John; Spaeth, Mary

    2013-07-09

    An optical gain architecture includes a pump source and a pump aperture. The architecture also includes a gain region including a gain element operable to amplify light at a laser wavelength. The gain region is characterized by a first side intersecting an optical path, a second side opposing the first side, a third side adjacent the first and second sides, and a fourth side opposing the third side. The architecture further includes a dichroic section disposed between the pump aperture and the first side of the gain region. The dichroic section is characterized by low reflectance at a pump wavelength and high reflectance at the laser wavelength. The architecture additionally includes a first cladding section proximate to the third side of the gain region and a second cladding section proximate to the fourth side of the gain region.

  9. Rheological evaluation of pretreated cladding removal waste

    SciTech Connect

    McCarthy, D.; Chan, M.K.C.; Lokken, R.O.

    1986-01-01

    Cladding removal waste (CRW) contains concentrations of transuranic (TRU) elements in the 80 to 350 nCi/g range. This waste will require pretreatment before it can be disposed of as glass or grout at Hanford. The CRW will be pretreated with a rare earth strike and solids removal by centrifugation to segregate the TRU fraction from the non-TRU fraction of the waste. The centrifuge centrate will be neutralized with sodium hydroxide. This neutralized cladding removal waste (NCRW) is expected to be suitable for grouting. The TRU solids removed by centrifugation will be vitrified. The goal of the Rheological Evaluation of Pretreated Cladding Removal Waste Program was to evaluate those rheological and transport properties critical to assuring successful handling of the NCRW and TRU solids streams and to demonstrate transfers in a semi-prototypic pumping environment. This goal was achieved by a combination of laboratory and pilot-scale evaluations. The results obtained during these evaluations were correlated with classical rheological models and scaled-up to predict the performance that is likely to occur in the full-scale system. The Program used simulated NCRW and TRU solid slurries. Rockwell Hanford Operations (Rockwell) provided 150 gallons of simulated CRW and 5 gallons of simulated TRU solid slurry. The simulated CRW was neutralized by Pacific Northwest Laboratory (PNL). The physical and rheological properties of the NCRW and TRU solid slurries were evaluated in the laboratory. The properties displayed by NCRW allowed it to be classified as a pseudoplastic or yield-pseudoplastic non-Newtonian fluid. The TRU solids slurry contained very few solids. This slurry exhibited the properties associated with a pseudoplastic non-Newtonian fluid.

  10. Ice-clad volcanoes

    USGS Publications Warehouse

    Waitt, Richard B.; Edwards, B.R.; Fountain, Andrew G.; Huggel, C.; Carey, Mark; Clague, John J.; Kääb, Andreas

    2015-01-01

    An icy volcano even if called extinct or dormant may be active at depth. Magma creeps up, crystallizes, releases gas. After decades or millennia the pressure from magmatic gas exceeds the resistance of overlying rock and the volcano erupts. Repeated eruptions build a cone that pokes one or two kilometers or more above its surroundings - a point of cool climate supporting glaciers. Ice-clad volcanic peaks ring the northern Pacific and reach south to Chile, New Zealand, and Antarctica. Others punctuate Iceland and Africa (Fig 4.1). To climb is irresistible - if only “because it’s there” in George Mallory’s words. Among the intrepid ascents of icy volcanoes we count Alexander von Humboldt’s attempt on 6270-meter Chimborazo in 1802 and Edward Whymper’s success there 78 years later. By then Cotopaxi steamed to the north.

  11. Detail of wall in highlift pumping station with Armstrong "Corkoustic" ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of wall in high-lift pumping station with Armstrong "Corkoustic" cladding and glazed brick. - Robert B. Morse Water Filtration Plant, 10700 and 10701 Columbia Pike, Silver Spring, Montgomery County, MD

  12. Multi-watt 589nm fiber laser source

    NASA Astrophysics Data System (ADS)

    Dawson, Jay W.; Drobshoff, Alex D.; Beach, Raymond J.; Messerly, Michael J.; Payne, Stephen A.; Brown, Aaron; Pennington, Deanna M.; Bamford, Douglas J.; Sharpe, Scott J.; Cook, David J.

    2006-02-01

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichio-metric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd 3+ fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the 1088nm 4-level laser transition. At 15W, the 938nm laser has an M2 of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  13. 469nm Fiber Laser Source

    SciTech Connect

    Drobshoff, A; Dawson, J W; Pennington, D M; Payne, S A; Beach, R

    2005-01-20

    We have demonstrated 466mW of 469nm light from a frequency doubled continuous wave fiber laser. The system consisted of a 938nm single frequency laser diode master oscillator, which was amplified in two stages to 5 Watts using cladding pumped Nd{sup 3+} fiber amplifiers and then frequency doubled in a single pass through periodically poled KTP. The 3cm long PPKTP crystal was made by Raicol Crystals Ltd. with a period of 5.9 {micro}m and had a phase match temperature of 47 degrees Centigrade. The beam was focused to a 1/e{sup 2} diameter in the crystal of 29 {micro}m. Overall conversion efficiency was 11% and the results agreed well with standard models. Our 938nm fiber amplifier design minimizes amplified spontaneous emission at 1088nm by employing an optimized core to cladding size ratio. This design allows the 3-level transition to operate at high inversion, thus making it competitive with the 1088nm 4-level transition. We have also carefully chosen the fiber coil diameter to help suppress propagation of wavelengths longer than 938 nm. At 2 Watts, the 938nm laser had an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >10:1).

  14. Multi-watt 589nm fiber laser source

    SciTech Connect

    DAWSON, J W; DROBSHOFF, A D; BEACH, R J; MESSERLY, M J; PAYNE, S A; BROWN, A; PENNINGTON, D M; BAMFORD, D J; SHARPE, S J; COOK, D J

    2006-01-19

    We have demonstrated 3.5W of 589nm light from a fiber laser using periodically poled stoichiometric Lithium Tantalate (PPSLT) as the frequency conversion crystal. The system employs 938nm and 1583nm fiber lasers, which were sum-frequency mixed in PPSLT to generate 589nm light. The 938nm fiber laser consists of a single frequency diode laser master oscillator (200mW), which was amplified in two stages to >15W using cladding pumped Nd{sup 3+} fiber amplifiers. The fiber amplifiers operate at 938nm and minimize amplified spontaneous emission at 1088nm by employing a specialty fiber design, which maximizes the core size relative to the cladding diameter. This design allows the 3-level laser system to operate at high inversion, thus making it competitive with the competing 1088nm 4-level laser transition. At 15W, the 938nm laser has an M{sup 2} of 1.1 and good polarization (correctable with a quarter and half wave plate to >15:1). The 1583nm fiber laser consists of a Koheras 1583nm fiber DFB laser that is pre-amplified to 100mW, phase modulated and then amplified to 14W in a commercial IPG fiber amplifier. As a part of our research efforts we are also investigating pulsed laser formats and power scaling of the 589nm system. We will discuss the fiber laser design and operation as well as our results in power scaling at 589nm.

  15. Clad Degradation - FEPs Screening Arguments

    SciTech Connect

    E. Siegmann

    2004-03-17

    The purpose of this report is to document the screening of the cladding degradation features, events, and processes (FEPs) for commercial spent nuclear fuel (CSNF). This report also addresses the effect of some FEPs on both the cladding and the CSNF, DSNF, and HLW waste forms where it was considered appropriate to address the effects on both materials together. This report summarizes the work of others to screen clad degradation FEPs in a manner consistent with, and used in, the Total System Performance Assessment-License Application (TSPA-LA). This document was prepared according to ''Technical Work Plan for Waste Form Degradation Modeling, Testing, and Analyses in Support of LA'' (BSC 2004a [DIRS 167796]).

  16. Multi-clad black display panel

    DOEpatents

    Veligdan, James T.; Biscardi, Cyrus; Brewster, Calvin

    2002-01-01

    A multi-clad black display panel, and a method of making a multi-clad black display panel, are disclosed, wherein a plurality of waveguides, each of which includes a light-transmissive core placed between an opposing pair of transparent cladding layers and a black layer disposed between transparent cladding layers, are stacked together and sawed at an angle to produce a wedge-shaped optical panel having an inlet face and an outlet face.

  17. Room-temperature capsule-shaped wavelength-scale metal-clad laser with enhanced side mode suppression

    NASA Astrophysics Data System (ADS)

    Xiao, Yi; Taylor, Richard J. E.; Yu, Chuanqing; Feng, Kaiyin; Tanemura, Takuo; Nakano, Yoshiaki

    2017-08-01

    We fabricate a capsule-shaped metal-clad wavelength-scale InP/InGaAs cavity and demonstrate room-temperature lasing at a wavelength of ˜1550 nm under pulsed optical pumping. By introducing an optimized curvature to the sidewalls of a conventional rectangular metal-clad laser, we effectively reduce the metallic loss of the transverse-electric mode and experimentally confirm a clear improvement in the side mode suppression ratio and slope efficiency.

  18. Femtosecond-laser inscribed double-cladding waveguides in Nd:YAG crystal: a promising prototype for integrated lasers.

    PubMed

    Liu, Hongliang; Chen, Feng; Vázquez de Aldana, Javier R; Jaque, D

    2013-09-01

    We report on the design and implementation of a prototype of optical waveguides fabricated in Nd:YAG crystals by using femtosecond-laser irradiation. In this prototype, two concentric tubular structures with nearly circular cross sections of different diameters have been inscribed in the Nd:YAG crystals, generating double-cladding waveguides. Under 808 nm optical pumping, waveguide lasers have been realized in the double-cladding structures. Compared with single-cladding waveguides, the concentric tubular structures, benefiting from the large pump area of the outermost cladding, possess both superior laser performance and nearly single-mode beam profile in the inner cladding. Double-cladding waveguides of the same size were fabricated and coated by a thin optical film, and a maximum output power of 384 mW and a slope efficiency of 46.1% were obtained. Since the large diameters of the outer claddings are comparable with those of the optical fibers, this prototype paves a way to construct an integrated single-mode laser system with a direct fiber-waveguide configuration.

  19. Vanadium-lined HT9 cladding tubes

    SciTech Connect

    Cohen, A.B.; Wiencek, T.C.; Tsai, H.

    1994-02-01

    Argonne National Laboratory`s Integral Fast Reactor (IFR) is an advanced liquid-metal-cooled reactor (ALMR) that uses a metallic (U-Pu-Zr alloy) fuel material in a steel cladding. The intimate contact between the fuel and fission products with the cladding at reactor operating temperatures (<600{degrees}C) can lead to chemical interaction and potential degradation of the cladding. One possible way to minimize the diffusion of the fuel and fission products into the steel cladding during irradiation is to place a physical barrier between the fuel and cladding. The barrier material chosen would have to be less susceptible to interaction at both the fuel and cladding interfaces. While there may be several methods by which a barrier can be placed between the fuel and cladding in the IFR fuel element, the two that have been pursued most recently are casting the fuel into a mold of the barrier material and then placing the casting and the mold into the steel cladding, and producing a lined, or ``duplex,`` cladding and placing the cast fuel ingot into the duplex cladding. The first method had some significant advantages, but it did not prove to be an effective barrier for fuel/cladding interaction. The second concept is the subject of this paper. For the purposes of testing the duplex cladding concept in-reactor, a fuel element has been designed and manufactured that contains a vanadium barrier between the fuel and cladding. Vanadium was chosen because in-reactor tests conducted by Argonne in the 1960`s indicated that vanadium alloy cladding had excellent metallurgical compatibility with U-Pu-Zr alloys as compared to steel. This paper describes the process for and results from lining IFR cladding tubes with a thin sheet of vanadium in order to produce duplex tubing for in-reactor testing.

  20. Reactor vessel cladding separate effects studies

    SciTech Connect

    Corwin, W.R.

    1985-01-01

    The existence of a layer of tough weld overlay cladding on the interior of a light-water reactor pressure vessel could mitigate damage caused during certain overcooling transients. The potential benefit of the cladding is that it could keep a short surface flaw, which would otherwise become long, from growing either by impeding crack initiation or by arresting a running crack. Two aspects critical to cladding behavior will be reported: irradiation effects on cladding toughness and the response of mechanically loaded, flawed structures in the presence of cladding. 15 refs., 24 figs., 6 tabs.

  1. ZIRCONIUM-CLADDING OF THORIUM

    DOEpatents

    Beaver, R.J.

    1961-11-21

    A method of cladding thorium with zirconium is described. The quality of the bond achieved between thorium and zirconium by hot-rolling is improved by inserting and melting a thorium-zirconium alloy foil between the two materials prior to rolling. (AEC)

  2. Active fiber polymer cladding temperature measurement under conditions of laser generation and amplification

    NASA Astrophysics Data System (ADS)

    Sypin, V. E.; Prusakov, K. Y.; Ryabushkin, O. A.

    2016-04-01

    Polymer cladding temperature of active fiber in lasing regime is important parameter as it allows determination of fiber core temperature that in turn effects laser generation and amplification efficiency. Besides polymer cladding has much lower temperature damage threshold comparing to fused silica. For example, 200 degrees Kelvin overheating of the polymer cladding can result in fiber degradation. In present paper we introduce novel and simple method for precise temperature measurement of active fibers cladding under conditions of laser generation and amplification. Dependence of longitudinal temperature distribution along active fibers on optical pump power can be determined. This method employs measurement of temperature dependent electrical resistance of the metal wire being in thermal contact with fiber polymer cladding. The wire is reeled on the active fiber segment. Under lasing or amplification conditions the polymer cladding of the active fiber is heated together with coiled metal wire resulting in its electrical resistance change. By measuring resistance variation one can determine the temperature of the given fiber section.

  3. Simulated transient behavior of HT9 cladding

    SciTech Connect

    Cannon, N.S.; Huang, F.H.; Hamilton, M.L.

    1988-09-01

    Simulated transient tests were performed on sections of HT9 fast- reactor fuel pin cladding irradiated to a fast fluence of nearly 16 /times/ 10/sup 22/ n/cm/sup 2/ at temperatures ranging from 370 to 620/degree/C. After removing fuel, these specimens were internally pressurized and heated at one of several constant rates (0.56, 5.6, or 110/degree/C/s) until specimen failure occurred. A slight reduction of strength was observed in irradiated cladding, particularly at 110/degree/C/s, when compared with transient results from unirradiated HT9 control specimens; however, this strength reduction did not correlate with either fluence or irradiation temperature. A small reduction of ductility was also observed for irradiated cladding failing at temperatures above 800/degree/C at the lower heating rates (0.56 or 5.6/degree/C/s); irradiated cladding was generally more ductile at 110/degree/C/s than unirradiated HT9 cladding. The HT9 cladding results were compared with similar transient data obtained previously from 20% Cold-Worked Type 316 Stainless Steel (316 SS) cladding. In the unirradiated state, this austenitic cladding is stronger and less ductile than HT9 cladding. However, the 316 SS cladding undergoes a significant loss of strength and ductility during irradiation when in contact with oxide fuel, by a mechanism labeled the fuel adjacency effect (FAE). The FAE is believed to be liquid metal embrittlement from fission products. The HT9 fuel pin cladding remained as strong or stronger than the 316 SS cladding when irradiated in contact with fuel, showing no evidence of the FAE up to the high fluences reported here. The ductility of the irradiated HT9 fuel pin cladding remained significantly greater than that of irradiated 316 SS cladding. 14 refs., 11 figs., 1 tab.

  4. Neodymium-doped phosphate fiber lasers with an all-solid microstructured inner cladding.

    PubMed

    Zhang, Guang; Zhou, Qinling; Yu, Chunlei; Hu, Lili; Chen, Danping

    2012-06-15

    We report on high-power fiber lasers based on index-guiding, all-solid neodymium-doped (Nd-doped) phosphate photonic crystal fiber (PCF) with a hexagonal-shaped inner cladding. The optimum fiber laser with a 36 cm length active fiber, generated up to 7.92 W output power at 1053 nm, which benefited from a high absorption coefficient for pump power due to its noncircular inner cladding. The guiding properties of the all-solid PCF were also investigated. A stable mode with a donut-shaped profile and a power-dependent laser beam quality have been observed experimentally and analyzed.

  5. CLAD DEGRADATION - FEPS SCREENING ARGUMENTS

    SciTech Connect

    R. Schreiner

    2004-10-21

    The purpose of this report is to evaluate and document the screening of the clad degradation features, events, and processes (FEPs) with respect to modeling used to support the Total System Performance Assessment-License Application (TSPA-LA). This report also addresses the effect of certain FEPs on both the cladding and the commercial spent nuclear fuel (CSNF), DOE-owned spent nuclear fuel (DSNF), and defense high-level waste (DHLW) waste forms, as appropriate to address the effects on multiple materials and both components (FEPs 2.1.09.09.0A, 2.1.09.11.0A, 2.1.11.05.0A, 2.1.12.02.0A, and 2.1.12.03.0A). These FEPs are expected to affect the repository performance during the postclosure regulatory period of 10,000 years after permanent closure. Table 1-1 provides the list of cladding FEPs, including their screening decisions (include or exclude). The primary purpose of this report is to identify and document the analysis, screening decision, and TSPA-LA disposition (for included FEPs) or screening argument (for excluded FEPs) for these FEPs related to clad degradation. In some cases, where a FEP covers multiple technical areas and is shared with other FEP reports, this report may provide only a partial technical basis for the screening of the FEP. The full technical basis for shared FEPs is addressed collectively by the sharing FEP reports. The screening decisions and associated TSPA-LA dispositions or screening arguments from all of the FEP reports are cataloged in a project-specific FEPs database.

  6. Effect of magnetic steering of the arc on clad quality in submerged arc strip cladding

    SciTech Connect

    Mallya, U.D. . Mechanical Engineering Dept.); Srinivas, H.S. . Production Engineering Dept.)

    1993-07-01

    Submerged arc strip cladding is often used when thickness of clad material is required. The productivity of this process has been improved by the use of higher welding currents and wider strips. The associated problems were arc blow, increased penetration and poor bead characteristics. Dilution is the parameter that controls almost all qualities of cladding. Magnetic steering reduces penetration, and hence, dilution and arc blow control. Stainless steel cladding on mild steel is often used to impart corrosion resistance. In such situations, the clad quality is specified by corrosion resistance, ferrite content and good fusion between clad metal and base metal. This paper discusses results of an investigation on the effect of an oscillating magnetic field used to steer the arc in submerged arc strip cladding using 60 X 0.5-mm 309L stainless steel strips, with varying magnetizing flux intensity and dwell time. The resulting test pieces were evaluated for parameters that imparted the best clad quality.

  7. Fabrication and test of a space power boiler feed electromagnetic pump. Part 1: Design and manufacture of pump

    NASA Technical Reports Server (NTRS)

    Gahan, J. W.; Powell, A. H.; Pileggi, P. T.; Thompson, S. P.

    1972-01-01

    A three-phase helical induction electromagnetic (EM) pump has been designed and built. This pump was designed for use as the boiler-feed pump of a potassium Rankine-cycle space electric power system. The pump is constructed of high temperature materials including a T-111 duct, Hiperco 27 magnetic material, nickel clad silver conductor wire, and a completely inorganic insulation system. The pump is designed to deliver 3.25 lb/sec potassium at 1000 F with a developed head of 240 psi while being cooled by 800 F NaK. At these conditions, the overall pump efficiency is expected to be 18%.

  8. Process development for cladding APT tungsten targets

    SciTech Connect

    Horner, M H; Barber, R; Dalder, E

    2000-11-27

    This report describes development of processes for cladding APT Target tungsten components with a thin layer (0.127-mm) of Alloy 718, Alloy 600 or 316L stainless steel alloy. The application requires that the cladding be thermally bonded to the tungsten in order to transfer heat generated in the tungsten volume to a surrounding coolant. High temperature diffusion bonding using the hot isostatic processing (HIP) technique was selected as the method for creating a metallurgical bond between pure tungsten tubes and rods and the cladding materials. Bonding studies using a uniaxially loaded vacuum hot press were conducted in preliminary experiments to determine acceptable time-temperature conditions for diffusion bonding. The results were successfully applied in cladding tungsten rods and tubes with these alloys. Temperatures 800-810 C were suitable for cladding tungsten with Alloy 600 and 316L stainless steel alloy, whereas tungsten was clad with Alloy 718 at 1020 C.

  9. Advanced Fuels Campaign Cladding & Coatings Meeting Summary

    SciTech Connect

    Not Listed

    2013-03-01

    The Fuel Cycle Research and Development (FCRD) Advanced Fuels Campaign (AFC) organized a Cladding and Coatings operational meeting February 12-13, 2013, at Oak Ridge National Laboratory (ORNL). Representatives from the U.S. Department of Energy (DOE), national laboratories, industry, and universities attended the two-day meeting. The purpose of the meeting was to discuss advanced cladding and cladding coating research and development (R&D); review experimental testing capabilities for assessing accident tolerant fuels; and review industry/university plans and experience in light water reactor (LWR) cladding and coating R&D.

  10. Protective claddings for high strength chromium alloys

    NASA Technical Reports Server (NTRS)

    Collins, J. F.

    1971-01-01

    The application of a Cr-Y-Hf-Th alloy as a protective cladding for a high strength chromium alloy was investigated for its effectiveness in inhibiting nitrogen embrittlement of a core alloy. Cladding was accomplished by a combination of hot gas pressure bonding and roll cladding techniques. Based on bend DBTT, the cladding alloy was effective in inhibiting nitrogen embrittlement of the chromium core alloy for up to 720 ks (200hours) in air at 1422 K (2100 F). A significant increase in the bend DBTT occurred with longer time exposures at 1422 K or short time exposures at 1589 K (2400 F).

  11. Pulsed Laser Cladding of Ni Based Powder

    NASA Astrophysics Data System (ADS)

    Pascu, A.; Stanciu, E. M.; Croitoru, C.; Roata, I. C.; Tierean, M. H.

    2017-06-01

    The aim of this paper is to optimize the operational parameters and quality of one step Metco Inconel 718 atomized powder laser cladded tracks, deposited on AISI 316 stainless steel substrate by means of a 1064 nm high power pulsed laser, together with a Precitec cladding head manipulated by a CLOOS 7 axes robot. The optimization of parameters and cladding quality has been assessed through Taguchi interaction matrix and graphical output. The study demonstrates that very good cladded layers with low dilution and increased mechanical proprieties could be fabricated using low laser energy density by involving a pulsed laser.

  12. Low loss depressed cladding waveguide inscribed in YAG:Nd single crystal by femtosecond laser pulses.

    PubMed

    Okhrimchuk, Andrey; Mezentsev, Vladimir; Shestakov, Alexander; Bennion, Ian

    2012-02-13

    A depressed cladding waveguide with record low loss of 0.12 dB/cm is inscribed in YAG:Nd(0.3at.%) crystal by femtosecond laser pulses with an elliptical beam waist. The waveguide is formed by a set of parallel tracks which constitute the depressed cladding. It is a key element for compact and efficient CW waveguide laser operating at 1064 nm and pumped by a multimode laser diode. Special attention is paid to mechanical stress resulting from the inscription process. Numerical calculation of mode distribution and propagation loss with the elasto-optical effect taken into account leads to the conclusion that the depressed cladding is a dominating factor in waveguide mode formation, while the mechanical stress only slightly distorts waveguide modes.

  13. Nuclear fuel elements having a composite cladding

    DOEpatents

    Gordon, Gerald M.; Cowan, II, Robert L.; Davies, John H.

    1983-09-20

    An improved nuclear fuel element is disclosed for use in the core of nuclear reactors. The improved nuclear fuel element has a composite cladding of an outer portion forming a substrate having on the inside surface a metal layer selected from the group consisting of copper, nickel, iron and alloys of the foregoing with a gap between the composite cladding and the core of nuclear fuel. The nuclear fuel element comprises a container of the elongated composite cladding, a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, an enclosure integrally secured and sealed at each end of said container and a nuclear fuel material retaining means positioned in the cavity. The metal layer of the composite cladding prevents perforations or failures in the cladding substrate from stress corrosion cracking or from fuel pellet-cladding interaction or both. The substrate of the composite cladding is selected from conventional cladding materials and preferably is a zirconium alloy.

  14. Cladding Alloys for Fluoride Salt Compatibility

    SciTech Connect

    Muralidharan, Govindarajan; Wilson, Dane F; Walker, Larry R; Santella, Michael L; Holcomb, David Eugene

    2011-06-01

    This report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for cladding large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high-power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for cladding inaccessible surfaces such as the interior surfaces of heat exchangers. An initial evaluation for performed on the quality of nickel claddings processed using the two selected cladding techniques.

  15. Annular Laser Beam Cladding Process Feasibility Study

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Alexander; Jeromen, Andrej; Levy, Gideon; Fujishima, Makoto; Govekar, Edvard

    In the paper a novel annular - ring shaped - laser beam cladding head and related cladding process are presented. In the cladding head a laser beam is shaped into an annular ring and guided coaxially with the powder tube disposing the powder jet in the centre of the focused annular laser beam ring. An experimental process feasibility analysis was performed using a Nd:YAG pulsed laser system with a maximal average power 250 W. Beside the known influencing parameters of laser cladding process including the powder mass flow, workpiece feeding velocity, and laser beam intensity, the important parameters related to the annular laser beam caustics were defined. The process feasibility and influence of the process parameters on powder catchment efficiency was analysed based on the cladding experiments of SS 316L powder on SS 304 workpiece material. The potential benefits related to the annular laser beam melt pool geometry and related powder catchment efficiency are discussed.

  16. Near-infrared lasers and self-frequency-doubling in Nd:YCOB cladding waveguides.

    PubMed

    Ren, Yingying; Chen, Feng; Vázquez de Aldana, Javier R

    2013-05-06

    A design of cladding waveguides in Nd:YCOB nonlinear crystals is demonstrated in this work. Compact Fabry-Perot oscillation cavities are employed for waveguide laser generation at 1062 nm and self-frequency-doubling at 531 nm, under optical pump at 810 nm. The waveguide laser shows slope efficiency as high as 55% at 1062 nm. The SFD green waveguide laser emits at 531 nm with a maximum power of 100 μW.

  17. Penis Pump

    MedlinePlus

    Penis pump Overview By Mayo Clinic Staff A penis pump is one of a few treatment options ... an erection sufficient for sex (erectile dysfunction). A penis pump consists of a plastic tube that fits ...

  18. Acoustic Pump

    NASA Technical Reports Server (NTRS)

    Heyman, Joseph S.

    1993-01-01

    Pump uses acoustic-radiation forces. Momentum transferred from sound waves to sound-propagating material in way resulting in net pumping action on material. Acoustic pump is solid-state pump. Requires no moving parts, entirely miniaturized, and does not invade pumped environment. Silent, with no conventional vibration. Used as pump for liquid, suspension, gas, or any other medium interacting with radiation pressure. Also used where solid-state pump needed for reliability and controllability. In microgravity environment, device offers unusual control for low flow rates. For medical or other applications in which contamination cannot be allowed, offers noninvasive pumping force.

  19. High-power air-cooled SiC-clad Nd:YVO4 slab lasers.

    PubMed

    Zhang, Rui; Niu, Jinfu; Xu, Jianqiu; Xu, Jingzhong

    2011-05-15

    We demonstrate a diode-pumped, air-cooled, 100 W class SiC-clad Nd:YVO(4) active slab laser based on diffusion bonding of two SiC plates to a thin Nd:YVO(4) slab. We obtained 83 W of cw output power with a slope efficiency of 27% without water cooling. This demonstration initiates a novel (to the best of our knowledge) cooling design for efficient removal of waste heat generated from the diode edge-pumped high-power slab laser at room temperature.

  20. Testing of uranium nitride fuel in T-111 cladding at 1200 K cladding temperature

    NASA Technical Reports Server (NTRS)

    Rohal, R. G.; Tambling, T. N.; Smith, R. L.

    1973-01-01

    Two groups of six fuel pins each were assembled, encapsulated, and irradiated in the Plum Brook Reactor. The fuel pins employed uranium mononitride (UN) in a tantalum alloy clad. The first group of fuel pins was irradiated for 1500 hours to a maximum burnup of 0.7-atom-percent uranium. The second group of fuel pins was irradiated for about 3000 hours to a maximum burnup of 1.0-atom-percent uranium. The average clad surface temperature during irradiation of both groups of fuel pins was approximately 1200 K. The postirradiation examination revealed the following: no clad failures or fuel swelling occurred; less than 1 percent of the fission gases escaped from the fuel; and the clad of the first group of fuel pins experienced clad embrittlement whereas the second group, which had modified assembly and fabrication procedures to minimize contamination, had a ductile clad after irradiation.

  1. Reduction of Liquid Clad Formation Due to Solid State Diffusion in Clad Brazing Sheet

    NASA Astrophysics Data System (ADS)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-12-01

    Warm forming operations have shown promise in expanding automotive heat exchanger designs by increasing forming limits of clad brazing sheet. The impact of isothermal holds below the clad melting temperature on subsequent brazeability has not previously been studied in detail. The effect of these holds on brazeability, as measured by the clad thickness loss due to solid state diffusion of Si out of the clad layer prior to clad melting, was assessed through parallel DSC and optical microscopy measurements, as well as through the use of a previously developed model. EPMA measurements were also performed to support the other measures. Overall, the same trends were predicted by DSC, microscopy, and the theoretical model; however, the DSC predictions were unable to accurately predict remaining clad thickness prior to melting, even after correcting the data for clad-core interactions. Microscopy measurements showed very good agreement with the model predictions, although there were slight discrepancies at short hold times due to the inability of the model to account for clad loss during heating to the brazing temperature. Further microscopy measurements showed that when the heating rate is set below a critical value, there is a reduction in the clad thickness from the as-received condition.

  2. Supercontinuum generation in chalcogenide double-clad fiber with near zero-flattened normal dispersion profile

    NASA Astrophysics Data System (ADS)

    Nagasaka, Kenshiro; Liu, Lai; Hoang Tuan, Tong; Cheng, Tonglei; Matsumoto, Morio; Tezuka, Hiroshige; Suzuki, Takenobu; Ohishi, Yasutake

    2017-09-01

    We demonstrate supercontinuum (SC) generation in a 2.8-cm-long chalcogenide double-clad fiber (Ch-DCF). The calculated chromatic dispersion of the fundamental mode shows that the Ch-DCF has flattened chromatic dispersion, which is within -10 ± 10 ps/nm/km from 3.8 to 12.6 μ {{m}} in the normal dispersion regime. The variation of SC spectra is investigated by changing the pump wavelength and pump peak power. The broadband SC spectra extending from 2 to 14 μm at the -40 dB level is observed when the pump wavelength of 10 μm and pump peak power of 1.3 MW. The SC generation is simulated by the scalar generalized nonlinear Schrödinger equation. The simulation results are mostly the same as the experimental results and show that the supercontinua generated in the Ch-DCF are highly coherent.

  3. Design of erbium doped double clad ZBLAN Fibre laser

    NASA Astrophysics Data System (ADS)

    Oladeji, A.; Phillips, A.; Lamrini, S.; Scholle, K.; Fuhrberg, P.; Seddon, A. B.; Benson, T. M.; Sujecki, S.

    2015-06-01

    A high powered octagonal double clad ZBLAN (33 μm/330 μm, NA=0.13) glass fibre for mid-infrared light generation is studied using a one dimensional rate equation model. The fibre laser design employs the concept of cascade lasing and includes up-conversion phenomena. The results obtained demonstrate that efficient cascade lasing may be achieved in practice without the need for fibre grating fabrication, as a sufficient level of feedback for laser action is provided by Fresnel light reflection at ZBLAN glass fibre air interfaces. Further enhancement of the laser efficiency can be achieved by terminating one of the fibre ends with a mirror. Simulation results show that the laser operation with 20 W of pump power at 0.98 μm wavelength can be achieved at 2.75 μm operating wavelength with Er3+ ion concentrations of 60,000 ppm.

  4. Laser Cladding of TiC for Better Titanium Components

    NASA Astrophysics Data System (ADS)

    Sampedro, J.; Pérez, I.; Carcel, B.; Ramos, J. A.; Amigó, V.

    Pure commercial titanium is widely used because of its high corrosion resistance and lower cost compared with other titanium alloys, in particular when there is no high wear requirements. Nevertheless, the wear resistance is poor and surface damage usually occurs in areas under contact loadings. Laser cladding is a suitable technique for manufacturing precise and defect free coatings of a dissimilar material with higher wear and corrosion resistance. In this work a good understanding of laser metal deposition mechanisms allowed to obtain defect free coatings of Ti6Al4 V and TiC metal matrix composite (MMC) using a flash lamp pumped Nd:YAG laser of 1 kW. A complete investigation of the process parameters is discussed and resultant wear properties are shown. The results show the feasibility to apply the process for manufacturing, improving or repairing high added value components for a wide range of industrial sectors.

  5. Double-clad nuclear fuel safety rod

    DOEpatents

    McCarthy, William H.; Atcheson, Donald B.; Vaidyanathan, Swaminathan

    1984-01-01

    A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

  6. PUMP CONSTRUCTION

    DOEpatents

    Strickland, G.; Horn, F.L.; White, H.T.

    1960-09-27

    A pump which utilizes the fluid being pumped through it as its lubricating fluid is described. This is achieved by means of an improved bearing construction in a pump of the enclosed or canned rotor type. At the outlet end of the pump, adjacent to an impeller mechanism, there is a bypass which conveys some of the pumped fluid to a chamber at the inlet end of the pump. After this chamber becomes full, the pumped fluid passes through fixed orifices in the top of the chamber and exerts a thrust on the inlet end of the pump rotor. Lubrication of the rotor shaft is accomplished by passing the pumped fluid through a bypass at the outlet end of the rotor shaft. This bypass conveys Pumped fluid to a cooling means and then to grooves on the surface of the rotor shait, thus lubricating the shaft.

  7. Industrial Pumps

    NASA Astrophysics Data System (ADS)

    1986-01-01

    A flow inducer is a device that increases the pump intake capacity of a Worthington Centrifugal pump. It lifts the suction pressure sufficiently for the rotating main impeller of the centrifugal pump to operate efficiently at higher fluid intake levels. The concept derives from 1960's NASA technology which was advanced by Worthington Pump Division. The pumps are used to recirculate wood molasses, a highly viscous substance.

  8. Industrial Pumps

    NASA Technical Reports Server (NTRS)

    1986-01-01

    A flow inducer is a device that increases the pump intake capacity of a Worthington Centrifugal pump. It lifts the suction pressure sufficiently for the rotating main impeller of the centrifugal pump to operate efficiently at higher fluid intake levels. The concept derives from 1960's NASA technology which was advanced by Worthington Pump Division. The pumps are used to recirculate wood molasses, a highly viscous substance.

  9. Optimizing the pumping configuration for the power scaling of in-band pumped erbium doped fiber amplifiers.

    PubMed

    Lim, Ee-Leong; Alam, Shaif-ul; Richardson, David J

    2012-06-18

    A highly efficient (~80%), high power (18.45 W) in-band, core pumped erbium/ytterbium co-doped fiber laser is demonstrated. To the best of our knowledge, this is the highest reported efficiency from an in-band pumped 1.5 µm fiber laser operating in the tens of watts regime. Using a fitted simulation model, we show that the significantly sub-quantum limit conversion efficiency of in-band pumped erbium doped fiber amplifiers observed experimentally can be explained by concentration quenching. We then numerically study and experimentally validate the optimum pumping configuration for power scaling of in-band, cladding pumped erbium doped fiber amplifiers. Our simulation results indicate that a ~77% power conversion efficiency with high output power should be possible through cladding pumping of current commercially available pure Erbium doped active fibers providing the loss experienced by the cladding guided 1535 nm pump due to the coating absorption can be reduced to an acceptable level by better coating material choice. The power conversion efficiency has the potential to exceed 90% if concentration quenching of erbium ions can be reduced via improvements in fiber design and fabrication.

  10. Surface protection of light metals by one-step laser cladding with oxide ceramics

    NASA Astrophysics Data System (ADS)

    Nowotny, S.; Richter, A.; Tangermann, K.

    1999-06-01

    Today, intricate problems of surface treatment can be solved through precision cladding using advanced laser technology. Metallic and carbide coatings have been produced with high-power lasers for years, and current investigations show that laser cladding is also a promising technique for the production of dense and precisely localized ceramic layers. In the present work, powders based on Al2O3 and ZrO2 were used to clad aluminum and titanium light alloys. The compact layers are up to 1 mm thick and show a nonporous cast structure as well as a homogeneous network of vertical cracks. The high adhesive strength is due to several chemical and mechanical bonding mechanisms and can exceed that of plasmasprayed coatings. Compared to thermal spray techniques, the material deposition is strictly focused onto small functional areas of the workpiece. Thus, being a precision technique, laser cladding is not recommended for large-area coatings. Examples of applications are turbine components and filigree parts of pump casings.

  11. Clad Degradation- Summary and Abstraction for LA

    SciTech Connect

    D. Stahl

    2004-10-01

    The purpose of this model report is to develop the summary cladding degradation abstraction that will be used in the Total System Performance Assessment for the License Application (TSPA-LA). Most civilian commercial nuclear fuel is encased in Zircaloy cladding. The model addressed in this report is intended to describe the postulated condition of commercial Zircaloy-clad fuel as a function of postclosure time after it is placed in the repository. Earlier total system performance assessments analyzed the waste form as exposed UO{sub 2}, which was available for degradation at the intrinsic dissolution rate. Water in the waste package quickly became saturated with many of the radionuclides, limiting their release rate. In the total system performance assessments for the Viability Assessment and the Site Recommendation, cladding was analyzed as part of the waste form, limiting the amount of fuel available at any time for degradation. The current model is divided into two stages. The first considers predisposal rod failures (most of which occur during reactor operation and associated activities) and postdisposal mechanical failure (from static loading of rocks) as mechanisms for perforating the cladding. Other fuel failure mechanisms including those caused by handling or transportation have been screened out (excluded) or are treated elsewhere. All stainless-steel-clad fuel, which makes up a small percentage of the overall amount of fuel to be stored, is modeled as failed upon placement in the waste packages. The second stage of the degradation model is the splitting of the cladding from the reaction of water or moist air and UO{sub 2}. The splitting has been observed to be rapid in comparison to the total system performance assessment time steps and is modeled to be instantaneous. After the cladding splits, the rind buildup inside the cladding widens the split, increasing the diffusion area from the fuel rind to the waste package interior. This model report summarizes

  12. Fuel cladding behavior under rapid loading conditions

    NASA Astrophysics Data System (ADS)

    Yueh, K.; Karlsson, J.; Stjärnsäter, J.; Schrire, D.; Ledergerber, G.; Munoz-Reja, C.; Hallstadius, L.

    2016-02-01

    A modified burst test (MBT) was used in an extensive test program to characterize fuel cladding failure behavior under rapid loading conditions. The MBT differs from a normal burst test with the use of a driver tube to simulate the expansion of a fuel pellet, thereby producing a partial strain driven deformation condition similar to that of a fuel pellet expansion in a reactivity insertion accident (RIA). A piston/cylinder assembly was used to pressurize the driver tube. By controlling the speed and distance the piston travels the loading rate and degree of sample deformation could be controlled. The use of a driver tube with a machined gauge section localizes deformation and allows for continuous monitoring of the test sample diameter change at the location of maximum hoop strain, during each test. Cladding samples from five irradiated fuel rods were tested between 296 and 553 K and loading rates from 1.5 to 3.5/s. The test rods included variations of Zircaloy-2 with different liners and ZIRLO, ranging in burn-up from 41 to 74 GWd/MTU. The test results show cladding ductility is strongly temperature and loading rate dependent. Zircaloy-2 cladding ductility degradation due to operational hydrogen pickup started to recover at approximately 358 K for test condition used in the study. This recovery temperature is strongly loading rate dependent. At 373 K, ductility recovery was small for loading rates less than 8 ms equivalent RIA pulse width, but longer than 8 ms the ductility recovery increased exponentially with increasing pulse width, consistent with literature observations of loading rate dependent brittle-to-ductile (BTD) transition temperature. The cladding ductility was also observed to be strongly loading rate/pulse width dependent for BWR cladding below the BTD temperature and Pressurized Water Reactor (PWR) cladding at both 296 and 553 K.

  13. Metal clad active fibres for power scaling and thermal management at kW power levels.

    PubMed

    Daniel, Jae M O; Simakov, Nikita; Hemming, Alexander; Clarkson, W Andrew; Haub, John

    2016-08-08

    We present a new approach to high power fibre laser design, consisting of a polymer-free all-glass optical fibre waveguide directly overclad with a high thermal conductivity metal coating. This metal clad active fibre allows a significant reduction in thermal resistance between the active fibre and the laser heat-sink as well as a significant increase in the operating temperature range. In this paper we show the results of a detailed thermal analysis of both polymer and metal coated active fibres under thermal loads typical of kW fibre laser systems. Through several different experiments we present the first demonstration of a cladding pumped aluminium-coated fibre laser and the first demonstration of efficient operation of a cladding-pumped fibre laser at temperatures of greater than 400 °C. Finally, we highlight the versatility of this approach through operation of a passively (radiatively) cooled ytterbium fibre laser head at an output power of 405 W in a compact and ultralight package weighing less than 100 g.

  14. Pump for spawning channels includes a turbine and motor. Turbine ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pump for spawning channels includes a turbine and motor. Turbine is Berkeley H-17500, model 8C2PH, Serial No. 2889, B.M. No. 4886 - Berkeley Pump Co. The Motor is G.E. Induction Motor, model 5K4256XA3YI, serial no. GAJ728337, Tri-Clad. View looking northeast. - Prairie Creek Fish Hatchery, Hwy. 101, Orick, Humboldt County, CA

  15. Heat pumps

    NASA Astrophysics Data System (ADS)

    Gilli, P. V.

    1982-11-01

    Heat pumps for residential/commercial space heating and hot tap water make use of free energy of direct or indirect solar heat and save from about 40 to about 70 percent of energy if compared to a conventional heating system with the same energy basis. In addition, the electrically driven compressor heat pump is able to substitute between 40% (bivalent alternative operation) to 100% (monovalent operation) of the fuel oil of an oilfired heating furnace. For average Central European conditions, solar space heating systems with high solar coverage factor show the following sequence of increasing cost effectiveness: pure solar systems (without heat pumps); heat pump assisted solar systems; solar assisted heat pump systems; subsoil/water heat pumps; air/water heat pumps; air/air heat pumps.

  16. Magnetocaloric pump

    NASA Technical Reports Server (NTRS)

    Brown, G. V.

    1973-01-01

    Very cold liquids and gases such as helium, neon, and nitrogen can be pumped by using magnetocaloric effect. Adiabatic magnetization and demagnetization are used to alternately heat and cool slug of pumped fluid contained in closed chamber.

  17. ELECTROMAGNETIC PUMP

    DOEpatents

    Pulley, O.O.

    1954-08-17

    This patent reiates to electromagnetic pumps for electricity-conducting fluids and, in particular, describes several modifications for a linear conduction type electromagnetic interaction pump. The invention resides in passing the return conductor for the current traversing the fiuid in the duct back through the gap in the iron circuit of the pump. Both the maximum allowable pressure and the efficiency of a linear conduction electromagnetic pump are increased by incorporation of the present invention.

  18. Nature's pumps

    NASA Astrophysics Data System (ADS)

    Vogel, Steven

    1994-10-01

    Although diverse in both form and function, the fluid-forcing devices in organisms have many of the capabilities and limitations of pumps of human design. Nature's pumps certainly look quite different from those of our technology, but all of them perform the same task. The author examines a few of these with an eye toward technological parallels and the two functional classes -- positive-displacement pumps and fluid-dynamic pumps.

  19. Femtosecond laser inscribed cladding waveguides in Nd:YAG ceramics: fabrication, fluorescence imaging and laser performance.

    PubMed

    Liu, Hongliang; Jia, Yuechen; Vázquez de Aldana, Javier Rodríguez; Jaque, Daniel; Chen, Feng

    2012-08-13

    We report on the fabrication of depressed cladding waveguide lasers in Nd:YAG (neodymium doped yttrium aluminum garnet, Nd:Y3Al5O12) ceramics microstructured by femtosecond laser pulses. Full control over the confined light spatial distribution is demonstrated by the fabrication of high contrast waveguides with hexagonal, circular and trapezoidal configurations. The confocal fluorescence measurements of the waveguides reveal that the original luminescence features of Nd3+ ions are well-preserved in the waveguide regions. Under optical pump at 808 nm, cladding waveguides showed continuous wave efficient laser oscillation. The maximum output power obtained at 1064.5 nm is ~181 mW with a slope efficiency as high as 44%, which suggests that the fabricated Nd:YAG ceramic waveguides are promising candidates for efficient integrated laser sources.

  20. Laser powder technology for cladding and welding

    NASA Astrophysics Data System (ADS)

    Arnold, J.; Volz, R.

    1999-06-01

    Laser powder technology offers several advantages compared to conventional cladding and welding techniques and is attracting increasing industrial interest. The laser materials processing group of the German Aerospace Center at Stuttgart, Germany, is currently developing these new methods for application in industrial process engineering. Key areas of the work include the design and implementation of a modular working head that can be universally used for laser welding and surface treatment, the development of powder nozzles for cladding and welding, and the construction of new systems for special applications (e.g., for inner cladding). Some of these developments are described, as well as some important examples that highlight the potential of welding and surface treatment using laser powder techniques.

  1. Roll Casting of Aluminum Alloy Clad Strip

    SciTech Connect

    Nakamura, R.; Tsuge, H.; Haga, T.; Watari, H.; Kumai, S.

    2011-01-17

    Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connected when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.

  2. Potential effects of gallium on cladding materials

    SciTech Connect

    Wilson, D.F.; Beahm, E.C.; Besmann, T.M.; DeVan, J.H.; DiStefano, J.R.; Gat, U.; Greene, S.R.; Rittenhouse, P.L.; Worley, B.A.

    1997-10-01

    This paper identifies and examines issues concerning the incorporation of gallium in weapons derived plutonium in light water reactor (LWR) MOX fuels. Particular attention is given to the more likely effects of the gallium on the behavior of the cladding material. The chemistry of weapons grade (WG) MOX, including possible consequences of gallium within plutonium agglomerates, was assessed. Based on the calculated oxidation potentials of MOX fuel, the effect that gallium may have on reactions involving fission products and possible impact on cladding performance were postulated. Gallium transport mechanisms are discussed. With an understanding of oxidation potentials and assumptions of mechanisms for gallium transport, possible effects of gallium on corrosion of cladding were evaluated. Potential and unresolved issues and suggested research and development (R and D) required to provide missing information are presented.

  3. OSCILLATORY PUMP

    DOEpatents

    Underwood, N.

    1958-09-23

    This patent relates to a pump suitable fur pumping highly corrosive gases wherein no lubricant is needed in the pumping chamber thus eliminating possible contamination sources. The chamber contains a gas inlet and outlet in each side, with a paddle like piston suspended by a sylphon seal between these pcrts. An external arrangement causes the paddle to oscillate rapidly between the ports, alternately compressing and exhausting the gas trapped on each side of the paddle. Since the paddle does nnt touch the chamber sides at any point, no lubricant is required. This pump is useful for pumping large quantities of uranium hexafluorine.

  4. 78 FR 7451 - Clad Steel Plate From Japan; Determination

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-01

    ... COMMISSION Clad Steel Plate From Japan; Determination On the basis of the record \\1\\ developed in the subject... order on clad steel plate from Japan would be likely to lead to continuation or recurrence of material... contained in USITC Publication 4370 (January 2013), entitled Clad Steel Plate from Japan: Investigation No...

  5. Suppression of parasitic oscillations in a core-doped ceramic Nd:YAG laser by Sm:YAG cladding.

    PubMed

    Huss, Rafael; Wilhelm, Ralf; Kolleck, Christian; Neumann, Jörg; Kracht, Dietmar

    2010-06-07

    The onset of parasitic oscillations limits the extraction efficiency and therefore energy scaling of Q-switched lasers. A solid-state laser was end pumped with a fiber-coupled diode laser and operated in q-cw as well as in passively Q-switched operation. For Q-switched operation, we demonstrate the suppression of parasitic oscillations in a core-doped ceramic Nd:YAG laser by Sm:YAG cladding.

  6. Pellet cladding mechanical interactions of ceramic claddings fuels under light water reactor conditions

    NASA Astrophysics Data System (ADS)

    Li, Bo-Shiuan

    Ceramic materials such as silicon carbide (SiC) are promising candidate materials for nuclear fuel cladding and are of interest as part of a potential accident tolerant fuel design due to its high temperature strength, dimensional stability under irradiation, corrosion resistance, and lower neutron absorption cross-section. It also offers drastically lower hydrogen generation in loss of coolant accidents such as that experienced at Fukushima. With the implementation of SiC material properties to the fuel performance code, FRAPCON, performances of the SiC-clad fuel are compared with the conventional Zircaloy-clad fuel. Due to negligible creep and high stiffness, SiC-clad fuel allows gap closure at higher burnup and insignificant cladding dimensional change. However, severe degradation of SiC thermal conductivity with neutron irradiation will lead to higher fuel temperature with larger fission gas release. High stiffness of SiC has a drawback of accumulating large interfacial pressure upon pellet-cladding mechanical interactions (PCMI). This large stress will eventually reach the flexural strength of SiC, causing failure of SiC cladding instantly in a brittle manner instead of the graceful failure of ductile metallic cladding. The large interfacial pressure causes phenomena that were previously of only marginal significance and thus ignored (such as creep of the fuel) to now have an important role in PCMI. Consideration of the fuel pellet creep and elastic deformation in PCMI models in FRAPCON provide for an improved understanding of the magnitude of accumulated interfacial pressure. Outward swelling of the pellet is retarded by the inward irradiation-induced creep, which then reduces the rate of interfacial pressure buildup. Effect of PCMI can also be reduced and by increasing gap width and cladding thickness. However, increasing gap width and cladding thickness also increases the overall thermal resistance which leads to higher fuel temperature and larger fission

  7. Theoretical study of pump power distribution on modal instabilities in high power fiber amplifiers

    NASA Astrophysics Data System (ADS)

    Tao, Rumao; Ma, Pengfei; Wang, Xiaolin; Zhou, Pu; Liu, Zejin

    2017-02-01

    Influence of pump power distribution on modal instabilities (MI) is studied numerically, which reveals that the MI threshold is dependent on the pump power distribution in fiber amplifiers and can be increased by optimizing the pump power distribution without any adjustment of other amplifier parameters. It shows that amplifiers with backward or bi-direction pump schemes have a higher threshold than those employing forward pump schemes. For backward pumped amplifiers employing fiber with core/clad diameter being 20/400 µm, the MI threshold yields a 42% increase compared to the forward pumped ones. For bi-direction pumped amplifiers, there exists an optimal power ratio between forward and backward pump power, which results in the highest threshold power. When amplifiers with core/clad diameter being 20/400 µm employ a bi-direction pump scheme at the optimal backward pump power fraction, the threshold can be increased by a factor of approximately 60% with respect to the forward pump configuration. The threshold increment factor reduces as the gain saturation effect weakens. It also shows that the MI threshold can be increased by employing multi-point side pump schemes.

  8. Advanced ceramic cladding for water reactor fuel

    SciTech Connect

    Feinroth, H.

    2000-07-01

    Under the US Department of Energy's Nuclear Energy Research Initiatives (NERI) program, continuous fiber ceramic composites (CFCCs) are being developed as cladding for water reactor fuel elements. The purpose is to substantially increase the passive safety of water reactors. A development effort was initiated in 1991 to fabricate CFCC-clad tubes using commercially available fibers and a sol-gel process developed by McDermott Technologies. Two small-diameter CFCC tubes were fabricated using pure alumina and alumina-zirconia fibers in an alumina matrix. Densities of {approximately}60% of theoretical were achieved. Higher densities are required to guarantee fission gas containment. This NERI work has just begun, and only preliminary results are presented herein. Should the work prove successful, further development is required to evaluate CFCC cladding and performance, including in-pile tests containing fuel and exploring a marriage of CFCC cladding materials with suitable advanced fuel and core designs. The possibility of much higher temperature core designs, possibly cooled with supercritical water, and achievement of plant efficiencies {ge}50% would be examined.

  9. Study and Behaviour of Prefabricated Composite Cladding

    NASA Astrophysics Data System (ADS)

    Sai Avinash, P.; Thiagarajan, N.; Santhi, A. S.

    2017-07-01

    The incessant population rise entailed for an expeditious construction at competitive prices that steered the customary path to the light weight structural components. This lead to construction of structural components using ferrocement. The load bearing structural cladding, sizing 3200x900x100 mm, is chosen for the study, which, is analyzed using the software ABAQUS 6.14 in accordance with the IS:875-87 Part1, IS:875-87 Part2, ACI 549R-97, ACI 318R-08 and NZS:3101-06 Part1 standards. The Ferrocement claddings (FCs) are fabricated to a scaled dimension of 400x115x38 mm. The light weight-high strength phenomena are corroborated by incorporating Glass Fibre Reinforced Polymer Laminates (GFRPL) of thickness 6mm, engineered with the aid of hand layup (wet layup) technique wielding epoxy resin, followed by curing under room temperature. The epoxy resin is employed for fastening ferrocement cladding with the Glass fiber reinforced polymer laminate, with the contemporary methodology. The compressive load carrying capacity of the amalgamated assembly, both in presence and absence of Glass Fibre Reinforced polymer laminates (GFRPL) on either side of Ferrocement cladding, has been experimented.

  10. Prism coupling into clad uniform optical waveguides

    SciTech Connect

    Revelli, J.F.; Sarid, D.

    1980-07-01

    The theory of prism coupling into multilayered dielectric slab waveguides is presented. In addition to including the possibility of high index cladding, the present theory also extends the region of validity of previously reported work to cover the regime of ''strong coupling''. The limiting conditions for validity of the present theory are that both ..cap alpha../sub m//k and ..cap alpha../sub m/ +- p/k be much smaller than either unity or vertical-bar..beta../sub m/-..beta../sub m/ +- pvertical-bar, where m is the mode under consideration, ..cap alpha../sub m/ is the leakage of that mode, and vertical-bar..beta../sub m/-..beta../sub m/ +- pvertical-bar is the separation of the effective indices of adjacent modes. A numerical example is presented in which the coupling efficiency into a uniform or slab waveguide with ..delta..n=0.002 is calculated for various cladding thicknesses with a cladding index of 2.5. The introduction of cladding is found to reduce coupling efficiency in this example due to increased phase mismatch between the incident and ''ideal'' beams.

  11. CLAD/BCLAD Examinations. Test Specifications.

    ERIC Educational Resources Information Center

    California Commission on Teacher Credentialing, Sacramento.

    This draft handbook provides descriptions and summaries of the six tests that California elementary and secondary teachers must pass to earn the Crosscultural, Language, and Academic Development (CLAD) or Bilingual, Crosscultural, Language, and Academic Development (BCLAD) certificates. The six tests include: (1) "Language Structure and…

  12. A fused side-pumping optical fiber coupler based on twisting

    NASA Astrophysics Data System (ADS)

    Yi, Bokai; Chang, Xinzu; Zhou, Xuanfeng; Chen, Zilun; Zhao, Guomin

    2014-12-01

    Pumping coupler technology is one of the critical technologies for high power laser and amplifier. Side-pumping technology can couple pumping beam into inner cladding of the double-clad fiber through the side of the fiber. Compared to the end-pumping technology by tapered fused bundle (TFB), it has many superiorities. That the signal fiber was not disconnected guarantees high transmission efficiency, providing the possibility of transmitting a high power signal. Additionally, the pump light is coupled into the double-cladding fiber all along the coupler's body (~5-10 cm long), which reduces the thermal effects caused by leakage of pumping light, resulting in high pump power handling capabilities. For the realization of reliable, rugged and efficient high power fiber amplifiers and fiber laser systems, a novel kind of fused side-pumping coupler based on twisting is developed. The complete simulations were carried out for the process of side-pumping. From detailed information about simulations, we found that the pump efficiencies, one of the vital parameters of pumping coupler, have a significant influence with coupling length, the numerical aperture (NA) and taper ratio of pump fiber. However, the diversification of the parameters drops the high transmission efficiency barely. Optimized the parameters in the simulations, the pump and signal coupling efficiencies are 97.3% and 99.4%, respectively. Based on theoretical analysis, the side-pumping coupler was demonstrated at the pump and signal coupling efficiencies are 91.2% and 98.4%, respectively. This fiber coupler can be implemented in almost any fiber laser or amplifier architecture.

  13. Steady-state heating of active fibres under optical pumping

    SciTech Connect

    Gainov, V V; Shaidullin, R I; Ryabushkin, Oleg A

    2011-07-31

    We have measured the temperature in the core of rare-earth-doped optical fibres under lasing conditions at high optical pump powers using a fibre Mach - Zehnder interferometer and probe light of wavelength far away from the absorption bands of the active ions. From the observed heating kinetics of the active medium, the heat transfer coefficient on the polymer cladding - air interface has been estimated. The temperature of the active medium is shown to depend on the thermal and optical properties of the polymer cladding. (fiber and integrated optics)

  14. Watt-level ~2 μm laser output in Tm3+-doped tungsten tellurite glass double-cladding fiber.

    PubMed

    Li, Kefeng; Zhang, Guang; Hu, Lili

    2010-12-15

    We report, for the first time to the best of our knowledge, a watt level cw fiber laser at ~2 μm from a piece of 40-cm-long newly developed highly thulium-doped (3.76 × 10(20) ions/cm(3)) tungsten tellurite glass double cladding fiber pumped by a commercial 800 nm laser diode. The maximum output power of the fiber laser reaches 1.12 W. The slope efficiency and the optical-optical efficiency with respect to the absorbed pump are 20% and 16%, respectively. The lasing threshold is 1.46 W, and the lasing wavelength is centered at 1937 nm.

  15. Supercontinuum generation in the normal dispersion regime using chalcogenide double-clad fiber

    NASA Astrophysics Data System (ADS)

    Nagasaka, Kenshiro; Hoang Tuan, Tong; Cheng, Tonglei; Matsumoto, Morio; Tezuka, Hiroshige; Suzuki, Takenobu; Ohishi, Yasutake

    2017-03-01

    We experimentally demonstrate mid-infrared (MIR) supercontinuum (SC) generation in a 2.8-cm-long chalcogenide double-clad fiber (Ch-DCF). The Ch-DCF made of As2Se3, AsSe2, and As2S5 glasses has near-zero chromatic dispersion in the normal dispersion regime. We pump the Ch-DCF using a 200 fs pulse laser at 10 µm, and obtain MIR SC extending from 2 to 14 µm. Numerical results show that the Ch-DCF has the potential of generating a highly coherent MIR SC light source.

  16. All-fiber designed narrow line-width 1.55μm double cladding fiber lasers

    NASA Astrophysics Data System (ADS)

    Su, Hongxin; Wu, Zhiyang; Xu, Lijing

    2014-11-01

    To develop 1.55μm high power lasers with compactness, narrow spectral line-width and high wavelength stability suitable for practical applications, EY-DCFLs built in all-fiber configuration are investigated. The experimental setups are composed of Er3+/Yb3+ co-doped double-clad gain fiber, multimode 976nm pump laser diode, double-clad fiber Bragg gratings (FBGs) and (1+1)x1 side pump couplers. FBGs with different reflectivity are applied as output reflectors, and forward-pump scheme and backward-pump scheme are performed respectively. As the efficiency and the spectral stability are considered simultaneously, EY-DCFL with low reflective FBG mirror and in backward-pump manner is more desirable. In the optimized all-fiber EY-DCFL, the maximum output power with an optical-optical efficiency of more than 17% is up to 1.5 W, and the wavelength is defined at 1550.8nm with a line-width about 0.03nm.

  17. Selection of energy optimized pump concepts for multi core and multi mode erbium doped fiber amplifiers.

    PubMed

    Krummrich, Peter M; Akhtari, Simon

    2014-12-01

    The selection of an appropriate pump concept has a major impact on amplifier cost and power consumption. The energy efficiency of different pump concepts is compared for multi core and multi mode active fibers. In preamplifier stages, pump power density requirements derived from full C-band low noise WDM operation result in superior energy efficiency of direct pumping of individual cores in a multi core fiber with single mode pump lasers compared to cladding pumping with uncooled multi mode lasers. Even better energy efficiency is achieved by direct pumping of the core in multi mode active fibers. Complexity of pump signal combiners for direct pumping of multi core fibers can be reduced by deploying integrated components.

  18. Highly efficient Er-Yb codoped double-clad fiber amplifier with an Yb-band resonant cavity

    NASA Astrophysics Data System (ADS)

    Han, Qun; Yao, Yunzhi; Tang, Xiaoyun; Chen, Yaofei; Yan, Wenchuan; Liu, Tiegen; Song, Huiling

    2017-02-01

    A high-power Er-Yb codoped fiber amplifier (EYDFA) with an Yb-band resonant cavity is investigated. By introducing a linear resonant cavity formed by a pair of high-reflection double-clad fiber Bragg gratings, the Yb-ASE problem of high-power pumped EYDFAs can be resolved and the efficiency of the amplifier can be notably improved. At a pump power of ~17 W, an output power of 7.25 W was experimentally achieved. The pump conversion efficiency and slope efficiency relative to the applied pump power are ~42.6% and ~45.6%, respectively. Moreover, due to the gain-clamping effect of the Yb cavity, the gain flatness of the amplifier is also evidently improved.

  19. Impulse Pump

    DTIC Science & Technology

    2016-06-17

    APPLICATIONS [0002] None. BACKGROUND OF THE INVENTION (1) Field of the Invention [0003] The present invention relates to an impulse pump for generating...impulse pump 15. The sleeve bearings 98 are affixed to the head block 90 to ease axial motion while the plunger 72 is under torsional loads. [0041

  20. Pumping system

    SciTech Connect

    Kime, J.A.

    1987-05-19

    This patent describes a gas-oil production system for pumping formation fluid in a well through a tubing string within which a down hole pump connects to a hydraulic stroking device through a rod string providing the pump including a plunger reciprocally driven by the hydraulic stroking device toward an upper terminal position during a plunger upstroke. The rod string normally supports the weight of a column of fluid and toward a lower terminal position at the end of a plunger downstroke during which the weight of the column fluid is normally transferred to the tubing string through fluid within the pump. The method for detecting when the well is pumped off comprises: supplying working fluid to the hydraulic stroking device to raise the hydraulic stroking device and thereby move the plunger from the lower terminal position to the upper terminal position; and removing the working fluid at a controlled rate from the hydraulic stroking device.

  1. Ferroelectric Pump

    NASA Technical Reports Server (NTRS)

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    2000-01-01

    A ferroelectric pump has one or more variable volume pumping chambers internal to a housing. Each chamber has at least one wall comprising a dome shaped internally prestressed ferroelectric actuator having a curvature and a dome height that varies with an electric voltage applied between an inside and outside surface of the actuator. A pumped medium flows into and out of each pumping chamber in response to displacement of the ferroelectric actuator. The ferroelectric actuator is mounted within each wall and isolates each ferroelectric actuator from the pumped medium, supplies a path for voltage to be applied to each ferroelectric actuator, and provides for positive containment of each ferroelectric actuator while allowing displacement of the entirety of each ferroelectric actuator in response to the applied voltage.

  2. Axial Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1997-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  3. Diode-Pumped Thulium (Tm)/Holmium (Ho) Composite Fiber 2.1-Micrometers Laser

    DTIC Science & Technology

    2015-09-01

    fibers of undoped clad (~ ∅ 200 μm), Tm-doped clad (~ ∅ 75 μm), and Ho-doped core (~ ∅ 23 μm). Through the 2-for-1 process, a single 808-nm diode light ...ARL-TR-7452 ● SEP 2015 US Army Research Laboratory Diode -Pumped Thulium (Tm)/Holmium (Ho) Composite Fiber 2.1-μm Laser by G...is no longer needed. Do not return it to the originator. ARL-TR-7452 ● SEP 2015 US Army Research Laboratory Diode -Pumped Thulium

  4. Generation of stable high order harmonic noise-like pulses in a passively mode-locked double clad fiber ring laser

    NASA Astrophysics Data System (ADS)

    Hernandez-Garcia, J. C.; Pottiez, O.; Ibarra-Escamilla, B.; Estudillo-Ayala, J. M.; Rojas-Laguna, R.; Kuzin, E.; Muñoz-Lopez, A.; Filoteo-Razo, J. D.

    2015-03-01

    We study a passively mode-locked double-clad Erbium-Ytterbium fiber ring laser producing noise-like pulse through nonlinear polarization evolution and polarization selection. Single noise-like pulsing is only observed at moderate pump power. As pump power is increased, and through polarization controllers adjustments, harmonic mode-locking of growing order were successively appearing. For pump powers close to the damage threshold of the setup, we reach harmonic orders beyond 1200 and repetition frequencies in excess of a quarter of a GHz. Finally, these experimental results could be useful in the quest for higher pulse energies and higher repetition rates in passively mode-locked fiber lasers.

  5. Magnetically controllable silicon microring with ferrofluid cladding.

    PubMed

    El Amili, A; Souza, M C M M; Vallini, F; Frateschi, N C; Fainman, Y

    2016-12-01

    We experimentally investigate the application of magnetic fluids (MFs) on integrated silicon photonics. Using a ferrofluid-clad silicon microring resonator, we demonstrate active control of resonances by applying an external magnetic field. Relatively high loaded quality factors on the order of 6000 are achieved, despite the optical losses introduced by the magnetic nanoparticles. We demonstrate resonance shifts of 185 pm in response to a 110 Oe strong magnetic field, corresponding to an overall refractive index change of -3.2×10-3 for the cladding MF. The combination of MFs and integrated photonics could potentially lead to the development of magnetically controllable optical devices and ultra-compact cost-effective magnetic field sensors.

  6. Fabrication and evaluation of a 500 W cladding-light stripper

    NASA Astrophysics Data System (ADS)

    Kliner, A.; Hou, Kai-Chung; Plötner, M.; Hupel, Ch.; Stelzner, Th.; Schreiber, T.; Eberhardt, R.; Tünnermann, A.

    2013-03-01

    Fiber lasers have reached kW levels of output power. To achieve this level it is necessary to use reliable high-power components that sustain these power levels. Double-clad fibers (DCFs) are often used in high-power fiber lasers. Cladding-light strippers (CLSs) are used to remove unwanted light from the inner cladding of the DCF. This unwanted light consists of residual pump light or signal light that leaked into the cladding, thus requiring that the CLS removes both high-NA (>0.4) and low-NA (<0.1) light. Often high-index polymers are used to remove the unwanted light from DCFs1,2,3. Because the CLS has to be able to withstand several 100W and most polymers are not capable of exceeding temperatures more than 200°C, we investigated a CLS without polymers, based on an etching process. We present results from a CLS that was tested up to 500W of stripped power. We determined the angle dependency of the stripping efficiency by launching both high- and low-NA light into the fiber and evaluating the NA attenuation. Furthermore, we measured the dependency of the stripping efficiency on the length of the etched area and the etching time. With optimized parameters an attenuation of more than 20 dB when launching high-NA light and 6 dB with low-NA light was achieved. The CLS did not show any degradation in terms of attenuation or thermal behavior in a six-hour stability test.

  7. Investigation of semiconductor clad optical waveguides

    NASA Technical Reports Server (NTRS)

    Batchman, T. E.; Carson, R. F.

    1985-01-01

    A variety of techniques have been proposed for fabricating integrated optical devices using semiconductors, lithium niobate, and glasses as waveguides and substrates. The use of glass waveguides and their interaction with thin semiconductor cladding layers was studied. Though the interactions of these multilayer waveguide structures have been analyzed here using glass, they may be applicable to other types of materials as well. The primary reason for using glass is that it provides a simple, inexpensive way to construct waveguides and devices.

  8. Microstructure and Mechanical Properties of Laser Clad and Post-cladding Tempered AISI H13 Tool Steel

    NASA Astrophysics Data System (ADS)

    Telasang, Gururaj; Dutta Majumdar, Jyotsna; Wasekar, Nitin; Padmanabham, G.; Manna, Indranil

    2015-05-01

    This study reports a detailed investigation of the microstructure and mechanical properties (wear resistance and tensile strength) of hardened and tempered AISI H13 tool steel substrate following laser cladding with AISI H13 tool steel powder in as-clad and after post-cladding conventional bulk isothermal tempering [at 823 K (550 °C) for 2 hours] heat treatment. Laser cladding was carried out on AISI H13 tool steel substrate using a 6 kW continuous wave diode laser coupled with fiber delivering an energy density of 133 J/mm2 and equipped with a co-axial powder feeding nozzle capable of feeding powder at the rate of 13.3 × 10-3 g/mm2. Laser clad zone comprises martensite, retained austenite, and carbides, and measures an average hardness of 600 to 650 VHN. Subsequent isothermal tempering converted the microstructure into one with tempered martensite and uniform dispersion of carbides with a hardness of 550 to 650 VHN. Interestingly, laser cladding introduced residual compressive stress of 670 ± 15 MPa, which reduces to 580 ± 20 MPa following isothermal tempering. Micro-tensile testing with specimens machined from the clad zone across or transverse to cladding direction showed high strength but failure in brittle mode. On the other hand, similar testing with samples sectioned from the clad zone parallel or longitudinal to the direction of laser cladding prior to and after post-cladding tempering recorded lower strength but ductile failure with 4.7 and 8 pct elongation, respectively. Wear resistance of the laser surface clad and post-cladding tempered samples (evaluated by fretting wear testing) registered superior performance as compared to that of conventional hardened and tempered AISI H13 tool steel.

  9. PWR cores with silicon carbide cladding

    SciTech Connect

    Dobisesky, J. P.; Carpenter, D.; Pilat, E.; Kazimi, M. S.

    2012-07-01

    The feasibility of using silicon carbide rather than Zircaloy cladding, to reach higher power levels and higher discharge burnups in PWRs has been evaluated. A preliminary fuel design using fuel rods with the same dimensions as in the Westinghouse Robust Fuel Assembly but with fuel pellets having 10 vol% central void has been adopted to mitigate the higher fuel temperatures that occur due to the lower thermal conductivity of the silicon carbide and to the persistence of the open clad-pellet gap over most of the fuel life. With this modified fuel design, it is possible to achieve 18 month cycles that meet present-day operating constraints on peaking factor, boron concentration, reactivity coefficients and shutdown margin, while allowing batch average discharge burnups up to 80 MWD/kgU and peak rod burnups up to 100 MWD/kgU. Power uprates of 10% and possibly 20% also appear feasible. For non-uprated cores, the silicon carbide-clad fuel has a clear advantage that increases with increasing discharge burnup. Even for comparable discharge burnups, there is a savings in enriched uranium. Control rod configuration modifications may be required to meet the shutdown margin criterion for the 20% up-rate. Silicon carbide's ability to sustain higher burnups than Zircaloy also allows the design of a licensable two year cycle with only 96 fresh assemblies, avoiding the enriched uranium penalty incurred with use of larger batch sizes due to their excessive leakage. (authors)

  10. Submersible pump

    SciTech Connect

    Todd, D. B.

    1985-08-27

    A method and apparatus for using a submersible pump to lift reservoir fluids in a well while having the tubing/casing annulus isolated from the produced fluids. The apparatus allows the submersible pump to be positioned above the annular packoff device. The apparatus comprises an outer shield that encloses the pump and can be attached to the production tubing. The lower end of the shield attaches to a short tubing section that seals with the annular packoff device or a receptacle above the annular packoff device.

  11. Cladded single crystal fibers for high power fiber lasers

    NASA Astrophysics Data System (ADS)

    Kim, W.; Shaw, B.; Bayya, S.; Askins, C.; Peele, J.; Rhonehouse, D.; Meyers, J.; Thapa, R.; Gibson, D.; Sanghera, J.

    2016-09-01

    We report on the recent progress in the development of cladded single crystal fibers for high power single frequency lasers. Various rare earth doped single crystal YAG fibers with diameters down to 17 μm with length > 1 m have been successfully drawn using a state-of-the-art Laser Heated Pedestal Growth system. Single and double cladding on rare earth doped YAG fibers have been developed using glasses where optical and physical properties were precisely matched to doped YAG core single crystal fiber. The double clad Yb:YAG fiber structures have dimensions analogous to large mode area (LMA) silica fiber. We also report successful fabrications of all crystalline core/clad fibers where thermal and optical properties are superior over glass cladded YAG fibers. Various fabrication methods, optical characterization and gain measurements on these cladded YAG fibers are reported.

  12. Clad fiber capacitor and method of making same

    DOEpatents

    Tuncer, Enis

    2012-12-11

    A clad capacitor and method of manufacture includes assembling a preform comprising a ductile, electrically conductive fiber; a ductile, electrically insulating cladding positioned on the fiber; and a ductile, electrically conductive sleeve positioned over the cladding. One or more preforms are then bundled, heated and drawn along a longitudinal axis to decrease the diameter of the ductile components of the preform and fuse the preform into a unitized strand.

  13. Clad fiber capacitor and method of making same

    DOEpatents

    Tuncer, Enis

    2013-11-26

    A clad capacitor and method of manufacture includes assembling a preform comprising a ductile, electrically conductive fiber; a ductile, electrically insulating cladding positioned on the fiber; a ductile, electrically conductive sleeve positioned over the cladding. One or more of the preforms are then bundled, heated and drawn along a longitudinal axis to decrease the diameter of the ductile components of the preform and fuse the preform into a unitized strand.

  14. Development and characterisations of WC–12Co microwave clad

    SciTech Connect

    Zafar, Sunny Sharma, Apurbba Kumar

    2014-10-15

    In the present work, WC–12Co based cermet clad was developed on AISI 304 stainless steel using microwave hybrid heating technique. The experimental trials were carried out in a 1.4 kW industrial multimode microwave applicator. The paper explains the major events occurring during microwave irradiation and formation of clad. The developed clads were subsequently characterised through field emission scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, X-ray diffraction, assessment of porosity and microhardness. The WC–12Co clads developed with an approximate thickness of 1 mm, illustrated excellent metallurgical bonding with substrate. The microstructure of the WC–12Co clad mainly consists of skeleton structured carbides embedded in tough metallic phase. The phase analysis of the developed clads indicate the presence of various stable and complex carbides like Co{sub 6}W{sub 6}C, Co{sub 3}W{sub 3}C and Fe{sub 6}W{sub 6}C. The uniform distribution of such carbides with skeleton-like morphology in the microstructure is indicative of high hardness of the clad. The developed clads were free from visible interfacial cracking and the clad porosity was found in the order of approximately 0.98%. The average microhardness of the WC–12Co microwave clads was observed to be 1135 ± 88 HV. - Highlights: • Microwave cladding of WC–12Co on AISI 304 stainless steel is carried out. • Skeleton-like structures of W–Co based carbides are embedded in metallic matrix. • Clad–substrate interface is free from un-melted and un-dissolved carbide particles. • Hardness of clad (1135 ± 88 HV) is 3.5 times that of the substrate (325 ± 49 HV)

  15. Transversely polarized source cladding for an optical fiber

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1994-01-01

    An optical fiber comprising a fiber core having a longitudinal symmetry axis is provided. An active cladding surrounds a portion of the fiber core and comprises light-producing sources which emit light in response to chemical or light excitation. The cladding sources are oriented transversely with respect to the longitudinal axis of the fiber core. This polarization results in a superior power efficiency compared to active cladding sources that are randomly polarized or longitudinally polarized parallel with the longitudinal symmetry axis.

  16. Electrokinetic pump

    DOEpatents

    Patel, Kamlesh D.

    2007-11-20

    A method for altering the surface properties of a particle bed. In application, the method pertains particularly to an electrokinetic pump configuration where nanoparticles are bonded to the surface of the stationary phase to alter the surface properties of the stationary phase including the surface area and/or the zeta potential and thus improve the efficiency and operating range of these pumps. By functionalizing the nanoparticles to change the zeta potential the electrokinetic pump is rendered capable of operating with working fluids having pH values that can range from 2-10 generally and acidic working fluids in particular. For applications in which the pump is intended to handle highly acidic solutions latex nanoparticles that are quaternary amine functionalized can be used.

  17. ION PUMP

    DOEpatents

    Milleron, N.

    1961-01-01

    An ion pump and pumping method are given for low vacuum pressures in which gases introduced into a pumping cavity are ionized and thereafter directed and accelerated into a quantity of liquid gettering metal where they are absorbed. In the preferred embodiment the metal is disposed as a liquid pool upon one electrode of a Phillips ion gauge type pump. Means are provided for continuously and remotely withdrawing and degassing the gettering metal. The liquid gettering metal may be heated if desired, although various combinations of gallium, indium, tin, bismuth, and lead, the preferred metals, have very low melting points. A background pressure of evaporated gettering metal may be provided by means of a resistance heated refractory metal wick protruding from the surface of the pcol of gettering metal.

  18. Slurry pumping: Pump performance prediction

    SciTech Connect

    Taccani, R.; Pediroda, V.; Reini, M.; Giadrossi, A.

    2000-07-01

    Centrifugal pumps are being used increasingly for transportation of slurries through pipelines. To design a slurry handling system it is essential to have a knowledge of the effects of suspended solids on the pump performance. A new test loop has been realized in the laboratory of the Energetics Department of the University of Trieste which allows pump performance to be determined at various pump speeds, with many different mixture concentrations and rheologies. The pump test rig consists of 150 mm diameter pipe with facilities for measuring suction and discharge pressure, flowrate, pump input power and speed, slurry density and temperature. In particular flowrate is measured by diverting flow into a weighing tank and timing a specified volume of slurry. An automatic PC based data acquisition system has been implemented. Preliminary tests with clear water show that performance can be measured with good repeatability and accuracy. The new test rig is used to verify the range of validity of the correlations to predict pump performance, available in literature and of that proposed by authors. This correlation, based on a Neural Network and not on a predefined analytical expression, can be easily improved with new experimental data.

  19. Nuclear reactor fuel element with vanadium getter on cladding

    DOEpatents

    Johnson, Carl E.; Carroll, Kenneth G.

    1977-01-01

    A nuclear reactor fuel element is described which has an outer cladding, a central core of fissionable or mixed fissionable and fertile fuel material and a layer of vanadium as an oxygen getter on the inner surface of the cladding. The vanadium reacts with oxygen released by the fissionable material during irradiation of the core to prevent the oxygen from reacting with and corroding the cladding. Also described is a method for coating the inner surface of small diameter tubes of cladding with a layer of vanadium.

  20. Microstructural Characterization of Cermet Cladding Developed Through Microwave Irradiation

    NASA Astrophysics Data System (ADS)

    Gupta, Dheeraj; Sharma, Apurbba Kumar

    2012-10-01

    In the present work, cladding of hardfacing WC10Co2Ni powder on austenitic stainless steel has been developed through a novel processing technique. The clads were developed using microwave hybrid heating. The clad of average thickness ~2 mm has been developed through the exposure of microwave radiation at frequency 2.45 GHz and power 900 W for the duration of 360 s. The developed clads were characterized using field emission scanning electron microscope, X-ray elemental analysis, X-ray diffraction, and measurement of Vicker's microhardness. The microstructure study of the clad showed good metallurgical bonding with substrate and revealed that clads are free from any visible interface cracking. Clads were formed with partial dilution of a thin layer of the substrate. The cermet microstructure mainly consists of relatively soft metallic matrix phase and uniformly distributed hard carbide phase with skeleton-like structure. The developed clads exhibit an average microhardness of 1064 ± 99 Hv. The porosity of developed clad has been significantly less at approximately 0.89%.

  1. Application of Regression Designs for Simulation of Laser Cladding

    NASA Astrophysics Data System (ADS)

    Zhang, Qunli; Anyakin, Mykola; Zhuk, Ruslan; Pan, Yi; Kovalenko, Volodymyr; Yao, Jianhua

    Laser cladding is a complicated process controlled by most parameters such as laser beam, properties of matrix and powder, treatment status of base material, laser cladding parameters etc. The best way to choose the working conditions cheaply and fast is to use the processing simulation. The statistical modeling was used in this paper, which was developed after regression design based on the experimental results of 2Cr13 steel cladding with diode laser robotized system. The influence degrees of technological factors (laser power, laser scanning speed, defocusing amount and powder feeding rate) on the dimensions and hardness of laser clad layers were investigated.

  2. Electroslag Strip Cladding of Steam Generators With Alloy 690

    SciTech Connect

    Consonni, M.; Maggioni, F.; Brioschi, F.

    2006-07-01

    The present paper details the results of electroslag cladding and tube-to-tubesheet welding qualification tests conducted by Ansaldo-Camozzi ESC with Alloy 690 (Alloy 52 filler metal) on steel for nuclear power stations' steam generators shell, tubesheet and head; the possibility of submerged arc cladding on first layer was also considered. Test results, in terms of chemical analysis, mechanical properties and microstructure are reproducible and confidently applicable to production cladding and show that electroslag process can be used for Alloy 52 cladding with exceptionally stable and regular operation and high productivity. The application of submerged arc cladding process to the first layer leads to a higher base metal dilution, which should be avoided. Moreover, though the heat affected zone is deeper with electroslag cladding, in both cases no coarsened grain zone is found due to recrystallization effect of second cladding layer. Finally, the application of electroslag process to cladding of Alloy 52 with modified chemical composition, was proved to be highly beneficial as it strongly reduces hot cracking sensitivity, which is typical of submerged arc cladded Alloy 52, both during tube-to-tubesheet welding and first re-welding. (authors)

  3. Hollow core anti-resonant fibres with split cladding

    NASA Astrophysics Data System (ADS)

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Luan, Feng; Yong, Ken-Tye; Yoo, Seongwoo

    2016-03-01

    A split cladding fibers (SCF) is proposed as an additional design to the anti-resonant type fiber. The introduced split cladding helps to reduce the fabrication distortion. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF. Fabrication of the SCF is demonstrated by the stack-and-draw technique. The near filed mode patterns are measured to prove the feasibility of this fiber design.

  4. Fuel pump

    SciTech Connect

    Bellis, P.D.; Nesselrode, F.

    1991-04-16

    This patent describes a fuel pump. It includes: a fuel reservoir member, the fuel reservoir member being formed with fuel chambers, the chambers comprising an inlet chamber and an outlet chamber, means to supply fuel to the inlet chamber, means to deliver fuel from the outlet chamber to a point of use, the fuel reservoir member chambers also including a bypass chamber, means interconnecting the bypass chamber with the outlet chamber; the fuel pump also comprising pump means interconnecting the inlet chamber and the outlet chamber and adapted to suck fuel from the fuel supply means into the inlet chamber, through the pump means, out the outlet chamber, and to the fuel delivery means; the bypass chamber and the pump means providing two substantially separate paths of fuel flow in the fuel reservoir member, bypass plunger means normally closing off the flow of fuel through the bypass chamber one of the substantially separate paths including the fuel supply means and the fuel delivery means when the bypass plunger means is closed, the second of the substantially separate paths including the bypass chamber when the bypass plunger means is open, and all of the chambers and the interconnecting means therebetween being configured so as to create turbulence in the flow of any fuel supplied to the outlet chamber by the pump means and bypassed through the bypass chamber and the interconnecting means.

  5. Stainless Steel Cladding Of Structural Steels By CO2 Laser Welding Techniques

    NASA Astrophysics Data System (ADS)

    Ludovico, A.; Daurelio, G.; Arcamone, O.

    1989-01-01

    Steel cladding processes are usually performed in different ways: hot roll cladding, strip cladding, weld cladding, explosion forming. For the first time, a medium power (2 KW c.w.) CO2 laser was used to clad structural steels (Fe 37C), 3 and 5 mm thick, with austenitic stainless steels (AISI 304 and AISI 316), 0.5 and 1.5 mm thick. The cladding technique we have developed uses the laser penetration welding process.

  6. Thermomechanical loading applied on the cladding tube during the pellet cladding mechanical interaction phase of a rapid reactivity initiated accident

    NASA Astrophysics Data System (ADS)

    Hellouin de Menibus, Arthur; Sercombe, Jerome; Auzoux, Quentin; Poussard, Christophe

    2014-10-01

    Calculations of the CABRI REP-Na5 pulse were performed with the ALCYONE code in order to determine the evolution of the thermomechanical loading applied on the cladding tube during the Pellet-Cladding Mechanical Interaction (PCMI) phase of a rapid Reactivity Initiated Accident (RIA) initiated at 280 °C that lasted 8.8 ms. The evolution of the following parameters are reported: the cladding temperature, heating rate, strain rate and loading biaxiality. The impact of these parameters on the cladding mechanical behavior and fracture are then briefly reviewed.

  7. Electrically pumped edge-emitting photonic bandgap semiconductor laser

    DOEpatents

    Lin, Shawn-Yu; Zubrzycki, Walter J.

    2004-01-06

    A highly efficient, electrically pumped edge-emitting semiconductor laser based on a one- or two-dimensional photonic bandgap (PBG) structure is described. The laser optical cavity is formed using a pair of PBG mirrors operating in the photonic band gap regime. Transverse confinement is achieved by surrounding an active semiconductor layer of high refractive index with lower-index cladding layers. The cladding layers can be electrically insulating in the passive PBG mirror and waveguide regions with a small conducting aperture for efficient channeling of the injection pump current into the active region. The active layer can comprise a quantum well structure. The quantum well structure can be relaxed in the passive regions to provide efficient extraction of laser light from the active region.

  8. Photonic lantern with cladding-removable fibers

    NASA Astrophysics Data System (ADS)

    Sun, Weimin; Yan, Qi; Bi, Yao; Yu, Haijiao; Liu, Xiaoqi; Xue, Jiuling; Tian, He; Liu, Yongjun

    2014-07-01

    Recently, spectral measurement becomes an important tool in astronomy to find exoplanets etc. The fibers are used to transfer light from the focal plate to spectrometers. To get high-resolution spectrum, the input slits of the spectrometers should be as narrow as possible. In opposite, the light spots from the fibers are circle, which diameters are clearly wider than the width of the spectrometer slits. To reduce the energy loss of the fiber-guide star light, many kinds of image slicers were designed and fabricated to transform light spot from circle to linear. Some different setup of fiber slicers are introduced by different research groups around the world. The photonic lanterns are candidates of fiber slicers. Photonic lantern includes three parts: inserted fibers, preform or tubing, taped part of the preform or tubing. Usually the optical fields concentrate in the former-core area, so the light spots are not uniform from the tapered end of the lantern. We designed, fabricated and tested a special kind of photonic lantern. The special fibers consist polymer cladding and doped high-index core. The polymer cladding could be easily removed using acetone bath, while the fiber core remains in good condition. We inserted the pure high-index cores into a pure silica tubing and tapered it. During the tapering process, the gaps between the inserted fibers disappeared. Finally we can get a uniform tapered multimode fiber end. The simulation results show that the longer the taper is, the lower the loss is. The shape of the taper should be controlled carefully. A large-zone moving-flame taper machine was fabricated to make the special photonic lantern. Three samples of photonic lanterns were fabricated and tested. The lanterns with cladding-removable fibers guide light uniform in the tapered ends that means these lanterns could collect more light from those ends.

  9. COMPARISON OF CLADDING CREEP RUPTURE MODELS

    SciTech Connect

    P. Macheret

    2000-06-12

    The objective of this calculation is to compare several creep rupture correlations for use in calculating creep strain accrued by the Zircaloy cladding of spent nuclear fuel when it has been emplaced in the repository. These correlations are used to calculate creep strain values that are then compared to a large set of experimentally measured creep strain data, taken from four different research articles, making it possible to determine the best fitting correlation. The scope of the calculation extends to six different creep rupture correlations.

  10. Metal clad aramid fibers for aerospace wire and cable

    NASA Technical Reports Server (NTRS)

    Tokarsky, Edward W.; Dunham, Michael G.; Hunt, James E.; Santoleri, E. David; Allen, David B.

    1995-01-01

    High strength light weight metal clad aramid fibers can provide significant weight savings when used to replace conventional metal wire in aerospace cable. An overview of metal clad aramid fiber materials and information on performance and use in braided electrical shielding and signal conductors is provided.

  11. Hot Forging of a Cladded Component by Automated GMAW Process

    NASA Astrophysics Data System (ADS)

    Rafiq, Muhammad; Langlois, Laurent; Bigot, Régis

    2011-01-01

    Weld cladding is employed to improve the service life of engineering components by increasing corrosion and wear resistance and reducing the cost. The acceptable multi-bead cladding layer depends on single bead geometry. Hence, in first step, the relationship between input process parameters and the single bead geometry is studied and in second step a comprehensive study on multi bead clad layer deposition is carried out. This paper highlights an experimental study carried out to get single layer cladding deposited by automated Gas Metal Arc Welding (GMAW) process and to find the possibility of hot forming of the cladded work piece to get the final hot formed improved structure. GMAW is an arc welding process that uses an arc between a consumable electrode and the welding pool with an external shielding gas and the cladding is done by alongside deposition of weld beads. The experiments for single bead were conducted by varying the three main process parameters wire feed rate, arc voltage and welding speed while keeping other parameters like nozzle to work distance, shielding gas and its flow rate and torch angle constant. The effect of bead spacing and torch orientation on the cladding quality of single layer from the results of single bead deposition was studied. Effect of the dilution rate and nominal energy on the cladded layer hot bending quality was also performed at different temperatures.

  12. Planar lightwave circuits: it's all in the cladding

    NASA Astrophysics Data System (ADS)

    Dumais, Patrick; Callender, Claire; Jiang, Jia; Blanchetière, Chantal; Celo, Dritan; Jacob, Sarkis; Ledderhof, Chris

    2011-08-01

    The top cladding layer in planar lightwave circuits (PLC) is more than an optical buffer. By variously doping, adjusting the thickness of, etching patterns in and annealing the cladding layers in waveguide devices, a wide range of sensors and photonic devices can be realized. The material properties of the cladding determine, for instance, the modal birefringence of the waveguides; knowledge and control of these properties can be harnessed to produce polarization-independent components. The fabrication of thermo-optically controlled switches and interferometers for tunable filtering and optical signal processing is possible through the creation of micro heaters on top of the cladding. The optimization of such components can benefit from engineering of the cladding, ranging from better planarization and thickness control, to selective etching to better confine the heat distribution and provide stress relief. In addition, the thermal properties of a given device can be radically enhanced by using a polymer layer as top cladding, which yields an order of magnitude increase in the temperature sensitivity, an invaluable enhancement that can be harnessed for phase-tunable waveguides or sensor structures. Long period gratings (LPGs) can be etched in the lower cladding to provide filtering, signal processing, or sensor functions. In a borophosphosilicate cladding, typically used in silica-on-silicon PLCs, control of the reflow properties through composition can be exploited to manufacture fillable microchannels that are monolithically integrated with solid-core devices, enabling a unique platform for sensing, signal processing, or nonlinear optics.

  13. DIFFUSION PUMP

    DOEpatents

    Levenson, L.

    1963-09-01

    A high-vacuum diffusion pump is described, featuring a novel housing geometry for enhancing pumping speed. An upright, cylindrical lower housing portion is surmounted by a concentric, upright, cylindrical upper housing portion of substantially larger diameter; an uppermost nozzle, disposed concentrically within the upper portion, is adapted to eject downwardly a conical sheet of liquid outwardly to impinge upon the uppermost extremity of the interior wall of the lower portion. Preferably this nozzle is mounted upon a pedestal rising coaxially from within the lower portion and projecting up into said upper portion. (AEC)

  14. Electrokinetic pump

    DOEpatents

    Hencken, Kenneth R.; Sartor, George B.

    2004-08-03

    An electrokinetic pump in which the porous dielectric medium of conventional electrokinetic pumps is replaced by a patterned microstructure. The patterned microstructure is fabricated by lithographic patterning and etching of a substrate and is formed by features arranged so as to create an array of microchannels. The microchannels have dimensions on the order of the pore spacing in a conventional porous dielectric medium. Embedded unitary electrodes are vapor deposited on either end of the channel structure to provide the electric field necessary for electroosmotic flow.

  15. Laboratory and field evaluations of clad Christmas tree equipment

    SciTech Connect

    Sisak, W.J. ); Gordon, J.R. )

    1991-02-01

    In this paper a methodology is presented for evaluating the corrosion resistance of clad equipment in sour environments. This paper describes the laboratory and field test programs used to evaluate the suitability for sour service of gate valves clad with Alloy UNS NO6625 by weld overlay and by hot, isostatic pressing (HIP). The laboratory tests used to evaluate corrosion and cracking resistance of the clads are reviewed. Experience with actual field installations of both types of clad valves is presented, and the test/inspection methods used to evaluate the equipment during and after the service period are discussed. Finally, laboratory and field results are compared to highlight key findings related to the clad valve bodies and to the trim components.

  16. Bendability of aluminiumand steel-clad chromium plates

    NASA Astrophysics Data System (ADS)

    Yoshida, Fusahito; Okada, Tatsuo; Itoh, Misao; Harada, Yasunori; Ohmori, Masanobu

    1998-05-01

    The present paper describes how the cladding of chromium plate with dissimilar metals improves the plastic bendability of the chromium. Three-point bending tests at various temperatures were performed for three types of chromium specimens: a monolithic chromium plate, aluminium- and steel-clad chromium plate. The aluminium-clad chromium plate was bent at 343 K up to a bent angle of 90 degrees without failure, even when the chromium layer was located outside of the plate (tension side), while the monolithic chromium plate could be bent exclusively at temperatures above 403 K. When the chromium layer was located inside of the steel-clad chromium plate (compression side), the plate was successfully bent at 307 K. The FE stress analysis of bending proved that the cladding of chromium plates with proper metals of different kinds is effective to reduce the tensile stress in chromium induced during bending and also the residual stress existing after bending operation.

  17. Test system to simulate transient overpower LMFBR cladding failure

    SciTech Connect

    Barrus, H.G.; Feigenbutz, L.V.

    1981-01-14

    One of the HEDL programs has the objective to experimentally characterize fuel pin cladding failure due to cladding rupture or ripping. A new test system has been developed which simulates a transient mechanically-loaded fuel pin failure. In this new system the mechanical load is prototypic of a fuel pellet rapidly expanding against the cladding due to various causes such as fuel thermal expansion, fuel melting, and fuel swelling. This new test system is called the Fuel Cladding Mechanical Interaction Mandrel Loading Test (FCMI/MLT). The FCMI/MLT test system and the method used to rupture cladding specimens very rapidly to simulate a transient event are described. Also described is the automatic data acquisition and control system which is required to control the startup, operation and shutdown of the very fast tests, and needed to acquire and store large quantities of data in a short time.

  18. Cladding embrittlement during postulated loss-of-coolant accidents.

    SciTech Connect

    Billone, M.; Yan, Y.; Burtseva, T.; Daum, R.; Nuclear Engineering Division

    2008-07-31

    The effect of fuel burnup on the embrittlement of various cladding alloys was examined with laboratory tests conducted under conditions relevant to loss-of-coolant accidents (LOCAs). The cladding materials tested were Zircaloy-4, Zircaloy-2, ZIRLO, M5, and E110. Tests were performed with specimens sectioned from as-fabricated cladding, from prehydrided (surrogate for high-burnup) cladding, and from high-burnup fuel rods which had been irradiated in commercial reactors. The tests were designed to determine for each cladding material the ductile-to-brittle transition as a function of steam oxidation temperature, weight gain due to oxidation, hydrogen content, pre-transient cladding thickness, and pre-transient corrosion-layer thickness. For short, defueled cladding specimens oxidized at 1000-1200 C, ring compression tests were performed to determine post-quench ductility at {le} 135 C. The effect of breakaway oxidation on embrittlement was also examined for short specimens oxidized at 800-1000 C. Among other findings, embrittlement was found to be sensitive to fabrication processes--especially surface finish--but insensitive to alloy constituents for these dilute zirconium alloys used as cladding materials. It was also demonstrated that burnup effects on embrittlement are largely due to hydrogen that is absorbed in the cladding during normal operation. Some tests were also performed with longer, fueled-and-pressurized cladding segments subjected to LOCA-relevant heating and cooling rates. Recommendations are given for types of tests that would identify LOCA conditions under which embrittlement would occur.

  19. Material selection for accident tolerant fuel cladding

    SciTech Connect

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; Snead, L. L.

    2015-09-14

    Alternative cladding materials are being investigated for accident tolerance, which can be defined as >100X improvement (compared to current Zr-based alloys) in oxidation resistance in steam environments at ≥1200°C for short (≤4 h) times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. Therefore, commercial Ti2AlC that is not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore may be challenging to use as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation assisted Cr-rich α’ formation. The composition effects and critical limits to retaining protective scale formation at >1400°C are still being evaluated.

  20. Material Selection for Accident Tolerant Fuel Cladding

    SciTech Connect

    Pint, Bruce A.; Terrani, Kurt A.; Yamamoto, Yukinori; Snead, Lance Lewis

    2015-01-01

    Alternative cladding materials to Zr-based alloys are being investigated for accident tolerance, which can be defined as > 100X improvement (compared to Zr-based alloys) in oxidation resistance to steam or steam-H2 environments at ≥ 1200°C for short times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. However, commercial Ti2AlC that was not single phase, formed a much thicker oxide at 1200°C in steam and significant TiO2, and therefore Ti2AlC may be challenging to form as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation-assisted α´ formation. The composition effects and critical limits to retaining protective scale formation at > 1400°C are still being evaluated.

  1. Material Selection for Accident Tolerant Fuel Cladding

    NASA Astrophysics Data System (ADS)

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; Snead, L. L.

    2015-09-01

    Alternative cladding materials to Zr-based alloys are being investigated for accident tolerance, which can be defined as >100X improvement (compared to Zr-based alloys) in oxidation resistance to steam or steam-H2 environments at ≥1473 K (1200 °C) for short times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases, and FeCrAl alloys. Recently reported low-mass losses for Mo in steam at 1073 K (800 °C) could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. However, commercial Ti2AlC that was not single phase, formed a much thicker oxide at 1473 K (1200 °C) in steam and significant TiO2, and therefore, Ti2AlC may be challenging to form as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1748 K (1475 °C), while reducing its Cr content to minimize susceptibility to irradiation-assisted α' formation. The composition effects and critical limits to retaining protective scale formation at >1673 K (1400 °C) are still being evaluated.

  2. Material selection for accident tolerant fuel cladding

    DOE PAGES

    Pint, B. A.; Terrani, K. A.; Yamamoto, Y.; ...

    2015-09-14

    Alternative cladding materials are being investigated for accident tolerance, which can be defined as >100X improvement (compared to current Zr-based alloys) in oxidation resistance in steam environments at ≥1200°C for short (≤4 h) times. After reviewing a wide range of candidates, current steam oxidation testing is being conducted on Mo, MAX phases and FeCrAl alloys. Recently reported low mass losses for Mo in steam at 800°C could not be reproduced. Both FeCrAl and MAX phase Ti2AlC form a protective alumina scale in steam. Therefore, commercial Ti2AlC that is not single phase, formed a much thicker oxide at 1200°C in steammore » and significant TiO2, and therefore may be challenging to use as a cladding or a coating. Alloy development for FeCrAl is seeking to maintain its steam oxidation resistance to 1475°C, while reducing its Cr content to minimize susceptibility to irradiation assisted Cr-rich α’ formation. The composition effects and critical limits to retaining protective scale formation at >1400°C are still being evaluated.« less

  3. Fuel/cladding compatibility of U-10Zr and U-5Fs fuels with advanced alloy cladding materials

    SciTech Connect

    Wood, E. L.; Porter, D. L.

    1985-05-01

    This study was concerned with the fuel/cladding interaction observed in diffusion couples of U-10 wt % Zr, U-5 wt % Fs fuels with HT-9, T91, D9, and 316 cladding at 650{sup 0}C and U-10 wt % Zr fuel with the cladding materials at 750{sup 0}C (U-5Fs forms a eutectic with these cladding alloys at temperatures just over 700{sup 0}C). The results presented here represent complete qualitative and semiquantitative findings for diffusion couples exposed for 720 hrs along with preliminary results of 2880 h exposures. The most important result of technological importance to IFR feasibility was that U-10 wt % Zr fuel was found to not significantly interact chemically with the cladding alloys. Moreover, energy-dispersive x-ray analyses demonstrated that metallographically observed banding in the fuel near the fuel/cladding interface was not related to chemical interdiffusion, but was related to zirconium migration towards the fuel/cladding interface. The zirconium migration may be related to oxygen availability at this location. The 2880 h samples were consistent with 720 h findings, indicating that essentially no fuel/cladding interdiffusion occurred, but showing additional zirconium migration.

  4. 976-nm passively mode-locked ytterbium-doped fiber laser core-pumped by 915-nm semiconductor laser

    NASA Astrophysics Data System (ADS)

    Zhou, Yue

    2016-11-01

    In this paper, we demonstrate an all-normal dispersion (ANDi) femtosecond YDFL. The laser operates around 976 nm via single-clad single-mode core-pumped method, which could enhance the slope efficiency up to 19% compared to that of 14% via double-clad multi-mode pumped method. The pulse repetition rate is 44.3 MHz, and pulse energy is approximately 1 nJ. Through external cavity pulse compression by a pair of gratings, the pulse duration can be compressed to 250 fs, nearly transform-limited.

  5. 18. Electrically driven pumps in Armory Street Pump House. Pumps ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. Electrically driven pumps in Armory Street Pump House. Pumps in background formerly drew water from the clear well. They went out of service when use of the beds was discontinued. Pumps in the foreground provide high pressure water to Hamden. - Lake Whitney Water Filtration Plant, Armory Street Pumphouse, North side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  6. Cladding material, tube including such cladding material and methods of forming the same

    DOEpatents

    Garnier, John E.; Griffith, George W.

    2016-03-01

    A multi-layered cladding material including a ceramic matrix composite and a metallic material, and a tube formed from the cladding material. The metallic material forms an inner liner of the tube and enables hermetic sealing of thereof. The metallic material at ends of the tube may be exposed and have an increased thickness enabling end cap welding. The metallic material may, optionally, be formed to infiltrate voids in the ceramic matrix composite, the ceramic matrix composite encapsulated by the metallic material. The ceramic matrix composite includes a fiber reinforcement and provides increased mechanical strength, stiffness, thermal shock resistance and high temperature load capacity to the metallic material of the inner liner. The tube may be used as a containment vessel for nuclear fuel used in a nuclear power plant or other reactor. Methods for forming the tube comprising the ceramic matrix composite and the metallic material are also disclosed.

  7. Femtosecond writing of depressed cladding waveguides in strongly cumulative regime

    NASA Astrophysics Data System (ADS)

    Bukharin, Mikhail A.; Khudyakov, Dmitriy V.; Vartapetov, Sergey K.

    2015-05-01

    We proposed a novel approach for direct femtosecond inscription of waveguides. It consisted in formation of cladding with reduced refractive index in fused silica. Depressed cladding was based on peripheral regions of individually written neighbored tracks, which should be inscribed in strongly cumulative regime. It was shown, that due to shot time interval between femtosecond laser pulses and relatively slow thermal diffusion, the exposed focal region surrounds by significantly wide cladding with reduced refracted index. Based on proposed approach we demonstrated depressed cladding waveguide inscription in fused silica using emission directly from commercially available femtosecond oscillator without correcting optical systems and second harmonic generation. It was shown, that the new approach provides formation of easily adjustable single mode waveguides with desired mode field diameter. Such depressed cladding waveguides exploit both advantages of fused silica material and depressed cladding geometry. We also verified our suggestion by experiment and inscribed depressed cladding waveguides with two different mode field diameters at similar femtosecond pulse characteristics. The obtained structures provided low propagation losses and good coupling with Gaussian mode. The waveguides supported propagation of both polarizations with nearly identical characteristics. Obtained experimental results were in good agreement with numerical simulation.

  8. Scanning Optics Enabled Possibilities and Challenges in Laser Cladding

    NASA Astrophysics Data System (ADS)

    Pekkarinen, Joonas

    Laser cladding using a scanned beam is quite a similar process than laser cladding using static optics (e.g. lens or mirror optics). The main difference comes from the manipulation of the laser beam. In laser cladding with scanning optics the laser beam is manipulated with a scanner so that the laser's area of influence can be shaped numerically. This increases cladding process flexibility. Scanning optics enable laser beam modification considerably versatile way than normal static optics can. This is due to possibility of numerical adjustment of scanning amplitude, laser power and scanning frequency. By modifying these parameters clad beads geometry can by modified quite freely. However scanned laser beam in surface modification process creates some restricting factors to the process. Mainly limitations for the process parameter values come from the dual characteristics of the energy input. This paper treats usability of scanning optics in laser cladding process in general level. In this paper is discussed how scanned beam can be used to increase the flexibility but also maters that limit the usage of scanned beam in cladding process. Process possibilities and limitations are presented in trough experimental data and examples.

  9. Hollow core anti-resonant fiber with split cladding.

    PubMed

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Yong, Ken-Tye; Luan, Feng; Yoo, Seongwoo

    2016-04-04

    An improved design for hollow core anti-resonant fibers (HAFs) is presented. A split cladding structure is introduced to reduce the fabrication distortion within design tolerance. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF and is comparable to that of the nested antiresonant nodeless fiber (NANF) with the same core size. In addition, the SCF allows stacking multiple layers of cladding rings to control the CL. The influences of the number of cladding layers and the cladding gap width on the CL of the SCFs have been studied. SCF with three cladding rings is fabricated by the stack-and-draw technique. A measured attenuation spectrum matches well with the calculation prediction. The measured near field mode patterns also prove the feasibility of our fiber design.

  10. Fuel and cladding tests for fuel failure safety analysis. [LMFBR

    SciTech Connect

    Hunter, C.W.; Johnson, G.D.; Hu, W.L.; Cannon, N.S.; Feigenbutz, L.V.; Hinman, C.A.; Slagle, D.O.; Bard, F.E.

    1982-01-01

    Three systems for testing fuel pin cladding were developed to support the determination of the mode and location of cladding failure during transient overpower events or transient undercooled overpower (TUCOP) conditions. The TUCOP FCTT system consists of exposing cladding specimens to thermal and loading conditions typical of TUCOP events. The Mandrel Loading Test (MLT) system was designed to produce cladding deformation and failure by internal mechanical interaction loading of a heated cladding specimen. The Cladding Rip Propagation Test (CRPT) system measures the rip propagation behavior of cladding at different temperatures. Fuel deformation and fission gas release tests were performed to better understand fuel behavior. High temperature creep and hot pressing tests on mixed oxide fuel indicate that an enhancement in the creep rate occurs at temperatures above 2300/sup 0/C and that only a small proportion of the fabrication fuel porosity can be closed at temperatures above 2500/sup 0/C. Two fission gas induced modes of gross fuel behavior under transient thermal conditions have been demonstrated, i.e., brittle fracture along grain boundaries and massive plastic swelling of the fission-gas-containing fuel.

  11. Heat pump

    SciTech Connect

    Apte, A.J.

    1982-11-30

    A single working fluid heat pump system having a turbocompressor with a first fluid input for the turbine and a second fluid input for the compressor, and a single output volute or mixing chamber for combining the working fluid output flows of the turbine and the compressor. The system provides for higher efficiency than single fluid systems whose turbine and compressor are provided with separate output volutes.

  12. Solar Pump

    NASA Technical Reports Server (NTRS)

    Pique, Charles

    1987-01-01

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

  13. Zircaloy cladding: Tough containment for spent fuel storage

    NASA Astrophysics Data System (ADS)

    Einziger, R. E.; Bosi, D. M.; Miller, A. K.

    The potential Zircaloy cladding degradation mechanisms are examined. It is concluded that in a limited air atmosphere, only stress rupture, stress corrosion cracking (SSC), and fatigue fracture could possibly compromise the cladding with stress-rupture of the pressurized fuel rods appearing to be the most likely mode of breach. Due to uncertainties in Blackburn's calculations, an experimental and theoretical study of stress rupture, stress corrosion cracking and the fatigue-fracture behavior of the cladding under postulated dynamic loads was conducted. Results presented may equally apply to dry storage.

  14. Oxidation performance of platinum-clad Mo-47Re alloy

    NASA Technical Reports Server (NTRS)

    Clark, Ronald K.; Wallace, Terryl A.

    1994-01-01

    The alloy Mo-47Re has favorable mechanical properties at temperatures above 1400 C, but it undergoes severe oxidation when used in air with no protective coating. To shield the alloy from oxidation, platinum cladding has been evaluated. The unprotected alloy undergoes catastrophic oxidation under static and dynamic oxidation conditions. The platinum cladding provides good protection from static and dynamic oxidation for moderate times at 1260 C. Samples tested for longer times under static oxidation conditions experienced severe oxidation. The data suggest that oxidation results from the transport of oxygen through the grain boundaries and through the pinhole defects of the platinum cladding.

  15. Innovations in laser cladding and direct metal deposition

    NASA Astrophysics Data System (ADS)

    Brückner, Frank; Nowotny, Steffen; Leyens, Christoph

    2012-03-01

    The present paper reviews recent progress in productivity, precision and quality of laser-based cladding and additive layer manufacturing. Recently, we have demonstrated the great benefits obtained from induction assisted laser cladding. This novel hybrid technology combines high deposition rates with excellent cladding properties. Laser-based direct metal deposition is a novel concept for the fabrication of components and repair as well as geometrical surface modifications. Newly developed nozzle design allows focused powder spots to generate wall thicknesses of about 30 μm. An in-depth understanding of the processes and the resulting materials properties is key for the development of technically viable and economically reasonable customized solutions.

  16. Increasing corrosion resistance of carbon steels by surface laser cladding

    NASA Astrophysics Data System (ADS)

    Polsky, V. I.; Yakushin, V. L.; Dzhumaev, P. S.; Petrovsky, V. N.; Safonov, D. V.

    2016-04-01

    This paper presents results of investigation of the microstructure, elemental composition and corrosion resistance of the samples of low-alloy steel widely used in the engineering, after the application of laser cladding. The level of corrosion damage and the corrosion mechanism of cladded steel samples were established. The corrosion rate and installed discharge observed at the total destruction of cladding were obtained. The regularities of structure formation in the application of different powder compositions were obtained. The optimal powder composition that prevents corrosion of samples of low-carbon low-alloy steel was established.

  17. Calculations of Stainless Steel-Aluminum Alloy Clad Forming Limit

    NASA Astrophysics Data System (ADS)

    Liu, Hongwei; Zhang, Peng

    Base on the Hosford's higher order yield criteria, the forming limit diagram of clad was developed with M-K theory at the positive strain ratio. The relationship of forming limit with thickness ratio, thickness irregular coefficient and the exponent of yield function were analyzed. The result show that the forming limit of clad material is between those of its component materials, and increases with the rising of stainless steel thickness ratio and the thickness irregular coefficient. So the forming limit can be improved by increase the stainless steel thickness ratio and improve the surface condition of the clad materials.

  18. Fabrication of oxide dispersion strengthened ferritic clad fuel pins

    SciTech Connect

    Zirker, L.R. ); Bottcher, J.H. ); Shikakura, S. ); Tsai, C.L. . Dept. of Welding Engineering); Hamilton, M.L. )

    1991-01-01

    A resistance butt welding procedure was developed and qualified for joining ferritic fuel pin cladding to end caps. The cladding are INCO MA957 and PNC ODS lots 63DSA and 1DK1, ferritic stainless steels strengthened by oxide dispersion, while the end caps are HT9 a martensitic stainless steel. With adequate parameter control the weld is formed without a residual melt phase and its strength approaches that of the cladding. This welding process required a new design for fuel pin end cap and weld joint. Summaries of the development, characterization, and fabrication processes are given for these fuel pins. 13 refs., 6 figs., 1 tab.

  19. Weld overlay cladding with iron aluminides

    SciTech Connect

    Goodwin, G.M.

    1995-08-01

    The hot and cold cracking tendencies of some early iron aluminide alloy compositions have limited their use in applications where good weldability is required. Using hot crack testing techniques invented at ORNL, and experimental determinations of preheat and postweld heat treatment needed to avoid cold cracking, we have developed iron aluminide filler metal compositions which can be successfully used to weld overlay clad various substrate materials, including 9Cr-1Mo steel, 2-1/4Cr-1Mo steel, and 300-series austenitic stainless steels. Dilution must be carefully controlled to avoid crack-sensitive deposit compositions. The technique used to produce the current filler metal compositions is aspiration-casting, i.e. drawing the liquid from the melt into glass rods. Future development efforts will involve fabrication of composite wires of similar compositions to permit mechanized gas tungsten arc (GTA) and/or gas metal arc (GMA) welding.

  20. Process for producing clad superconductive materials

    DOEpatents

    Cass, Richard B.; Ott, Kevin C.; Peterson, Dean E.

    1992-01-01

    A process for fabricating superconducting composite wire by the steps of placing a superconductive precursor admixture capable of undergoing a self propagating combustion in stoichiometric amounts sufficient to form a superconductive product within a metal tube, sealing one end of said tube, igniting said superconductive precursor admixture whereby said superconductive precursor admixture endburns along the length of the admixture, and cross-section reducing said tube at a rate substantially equal to the rate of burning of said superconductive precursor admixture and at a point substantially planar with the burnfront of the superconductive precursor mixture, whereby a clad superconductive product is formed in situ, the product characterized as superconductive without a subsequent sintering stage, is disclosed.

  1. Silver-clad Bi-2223 processing

    NASA Astrophysics Data System (ADS)

    Lay, K. W.; Arendt, R. H.; Tkaczyk, J. E.; Garbauskas, M. F.

    1992-04-01

    One of the most promising techniques for the production of long lengths of high Tc Superconductors utilizes themechanical deformation and subsequent heat treatment of silver-clad bismuth cuprates. Some recent experiments on Bi 1.7Pb0.3Sr2Ca2+x Cu3+xOy, with x=0.2, 0.4, and 0.75, processed by packing powder ina silver tube followed by swaging, drawing, and rolling are described. The effect of the initial powder composition, both cation ratios and phase composition, on the critical current of the composite tapes are explored. Different final deformation methods and heat treatment schedules also are discussed. A set of guidelines for the production of high Jc 2223 tapes is given.

  2. Laser cladding of bioactive glass coatings.

    PubMed

    Comesaña, R; Quintero, F; Lusquiños, F; Pascual, M J; Boutinguiza, M; Durán, A; Pou, J

    2010-03-01

    Laser cladding by powder injection has been used to produce bioactive glass coatings on titanium alloy (Ti6Al4V) substrates. Bioactive glass compositions alternative to 45S5 Bioglass were demonstrated to exhibit a gradual wetting angle-temperature evolution and therefore a more homogeneous deposition of the coating over the substrate was achieved. Among the different compositions studied, the S520 bioactive glass showed smoother wetting angle-temperature behavior and was successfully used as precursor material to produce bioactive coatings. Coatings processed using a Nd:YAG laser presented calcium silicate crystallization at the surface, with a uniform composition along the coating cross-section, and no significant dilution of the titanium alloy was observed. These coatings maintain similar bioactivity to that of the precursor material as demonstrated by immersion in simulated body fluid. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Reliability of hard plastic clad silica fibers

    NASA Astrophysics Data System (ADS)

    Skutnik, Bolesh J.; Spaniol, Stefan

    2006-04-01

    New formulations of cladding materials have become available in recent times for Hard Plastic Clad Silica (HPCS) fibers, Initial data showed gains in some properties, particularly dynamic strength, especially for high numerical aperture (NA) fibers. A systematic study has been undertaken to determine the full strength and fatigue behavior of these HPCS fibers and to make comparisons to earlier HPCS fibers. Preliminary results, now confirmed, has shown improved median dynamic strength and higher Weibull slope. Full results are presented below including fatigue behavior and optical properties. These fibers have many applications and benefits in the high power delivery and medical laser uses as highlighted below. High power diode laser systems with their laser diode bars and arrays not only require special fibers to couple directly to the diode emitters, but also require special fibers to couple from the laser to application sites. These latter power delivery fibers are much larger than the internal fibers but still must be flexible, and have not only good strength but also good fatigue behavior. This particularly important industrial systems using robotic arms to apply the high power laser energy at a treatment site. The optical properties of HPCS fibers are well suited for the needs of the delivery of high power from diode laser bars and arrays to an application site. Benefits of strong median dynamic strengths and tighter flaw distributions in such cases will be discussed. Many medical applications, especially endoscopic ones, can benefit from the use of highly flexible, high NA, cost effective, HPCS optical fibers. Benefits of high strength and good fatigue behavior for such fibers in endoscopic procedures, including laser surgery, are discussed briefly including implications for mechanical reliability in medical and industrial settings.

  4. Linearly-polarized Tm-doped double-clad fiber laser

    NASA Astrophysics Data System (ADS)

    Yang, D. Z.; Liu, W.; Chen, T.; Ye, W.; Shen, Y. H.

    2010-08-01

    We report a linearly polarized Tm doped fiber laser. The fiber laser was set up by using a piece of polarization maintaining Tm doped double clad fiber of 5 m length as gain medium and a polarization beam splitter as a polarization selector. The fiber laser was pumped by a fiber pigtailed laser diode working at 790 nm with a maximum output power of 90 W. The linearly polarized Tm laser operated at wavelength around 2030 nm. A maximum output power up to 21.9 W was achieved when the pump power was 63.27 W with a threshold of 11.92 W, a slope efficiency of about 43.7%, and a polarization extinction ratio of 92.7% (11.37 dB). In addition to the blue fluorescence, we also observed the violet fluorescence under high pump power level. The up-conversion fluorescence was considered to be attributed to the 1 G 4 → 3 H 6, and 1 D 2 → 3 F 4 transitions of Tm ions, respectively.

  5. Methods for characterization of mechanical and electrical prosthetic vacuum pumps.

    PubMed

    Komolafe, Oluseeni; Wood, Sean; Caldwell, Ryan; Hansen, Andrew; Fatone, Stefania

    2013-01-01

    Despite increasingly widespread adoption of vacuum-assisted suspension systems in prosthetic clinical practices, there remain gaps in the body of scientific knowledge guiding clinicians' choices of existing products. In this study, we identified important pump-performance metrics and developed techniques to objectively characterize the evacuation performance of prosthetic vacuum pumps. The sensitivity of the proposed techniques was assessed by characterizing the evacuation performance of two electrical (Harmony e-Pulse [Ottobock; Duderstadt, Germany] and LimbLogic VS [Ohio Willow Wood; Mt. Sterling, Ohio]) and three mechanical (Harmony P2, Harmony HD, and Harmony P3 [Ottobock]) prosthetic pumps in bench-top testing. Five fixed volume chambers ranging from 33 cm(3) (2 in.(3)) to 197 cm(3) (12 in.(3)) were used to represent different air volume spaces between a prosthetic socket and a liner-clad residual limb. All measurements were obtained at a vacuum gauge pressure of 57.6 kPa (17 inHg). The proposed techniques demonstrated sensitivity to the different electrical and mechanical pumps and, to a lesser degree, to the different setting adjustments of each pump. The sensitivity was less pronounced for the mechanical pumps, and future improvements for testing of mechanical vacuum pumps were proposed. Overall, this study successfully offers techniques feasible as standards for assessing the evacuation performance of prosthetic vacuum pump devices.

  6. Energy saving pump and pumping system

    SciTech Connect

    Chang, K.C.

    1983-08-02

    A centrifugal pump and a pumping system are disclosed that recover hydraulic energy in response to flow capacity reduction and spontaneously provide a recirculating flow at low capacities when pump cooling is needed. From a upstream source the fluid is guided by two suction lines to two parallel pumping mechanisms housed by a common discharge casing. Said pumping mechanisms have a combined hydraulic characteristic that the first pumping mechanism will force a reverse flow through the second pumping mechanism, when pump discharge is reduced by the system below a certain low flow rate. The reverse flow will then return to the upstream fluid source through a suction line. The pump is the protected from overheating by a circulating flow at low flow capacities. At the same time, said reverse flow generates a turbine action on the second pumping mechanism and transmits the contained hydraulic energy back to the rotor and thereby results in power saving at low flow capacities.

  7. All-solid very large mode area ytterbium-doped silica microstructured fiber based on accurate control on cladding index.

    PubMed

    Wei, Huifeng; Chen, Kangkang; Yang, Yucheng; Li, Jinyan

    2016-04-18

    We have demonstrated a new approach for developing very large mode area silica-based microstructured Ytterbium (Yb)-doped fibers. The microstructured region acting as pump cladding around the core is composed by periodically arranged low-index Fluorine-doped silica inclusions with an extremely low filling ratio of 0.088. To the best of our knowledge, we achieved the most accurate controlling on cladding index by 1 × 10-5 via our passively doped cladding (PDC) method. Two fibers with 127μm and 50μm core diameter respectively were fabricated from the same final preform designed by this approach. It is verified that our 50μm core diameter fiber can maintain robust single mode behavior at 1064nm wavelength. The advantage of an all-solid structure along with a much simpler fabrication process makes our approach very suitable for realizing very large mode area fibers for high power fiber laser application.

  8. Numerical investigation of highly coherent mid-infrared supercontinuum generation in chalcogenide double-clad fiber

    NASA Astrophysics Data System (ADS)

    Nagasaka, Kenshiro; Liu, Lai; Tuan, Tong Hoang; Cheng, Tonglei; Matsumoto, Morio; Tezuka, Hiroshige; Suzuki, Takenobu; Ohishi, Yasutake

    2017-07-01

    It is shown that chalcogenide double-clad fibers (Ch-DCFs) have large potential to realize the highly coherent mid-infrared (MIR) supercontinuum generation. We design the Ch-DCFs with flatter chromatic dispersion and smaller effective mode diameter than chalcogenide step index fibers in the MIR region. We numerically investigate MIR supercontinuum generation in designed Ch-DCFs. It is numerically demonstrated that highly coherent MIR supercontinuum extending from 3.3 to 10.4 μm in the Ch-DCFs can be generated by pumping with hyperbolic secant pulse at 6 μm, the peak power of 2 kW, and the full width at half maximum of 300 fs.

  9. Linearly polarized operation of a Yb3+-doped double-clad fiber laser

    NASA Astrophysics Data System (ADS)

    Feng, De-jun; Huang, Wen-yu; Zhang, Pei-pei; Zhou, Jun; Gu, Xi-jia

    2013-09-01

    In this work an all-fiber linearly-polarized Yb-doped double-clad fiber laser is proposed, in which the resonance cavity is composed of a pair of polarization maintaining fiber Bragg gratings (PM-FBGs). The polarization hole burning is enhanced by the selective polarization feedback by the PM-FBGs. A three-port polarization beam splitter with fiber pigtail was inserted into the laser cavity to select different polarization states. The laser features wavelength of 1069.72 nm and 1069.98 nm, output power of 125 mW, SNR of 45 dB, slope efficiency of 52%, as well as linewidth of 30.7 pm. The polarization characteristics of the laser are studied by measuring the laser power transmitted through a rotating Glan- Thomson polarizer. The degree of polarization of each lasing line is over 12 dB under different pump levels.

  10. Optical lattice-like cladding waveguides by direct laser writing: fabrication, luminescence, and lasing.

    PubMed

    Nie, Weijie; He, Ruiyun; Cheng, Chen; Rocha, Uéslen; Rodríguez Vázquez de Aldana, Javier; Jaque, Daniel; Chen, Feng

    2016-05-15

    We report on the fabrication of optical lattice-like waveguide structures in an Nd:YAP laser crystal by using direct femtosecond laser writing. With periodically arrayed laser-induced tracks, the waveguiding cores can be located in either the regions between the neighbored tracks or the central zone surrounded by a number of tracks as outer cladding. The polarization of the femtosecond laser pulses for the inscription has been found to play a critical role in the anisotropic guiding behaviors of the structures. The confocal photoluminescence investigations reveal different stress-induced modifications of the structures inscribed by different polarization of the femtosecond laser beam, which are considered to be responsible for the refractive index changes of the structures. Under optical pump at 808 nm, efficient waveguide lasing at ∼1  μm wavelength has been realized from the optical lattice-like structure, which exhibits potential applications as novel miniature light sources.

  11. Composite polymer-glass edge cladding for laser disks

    DOEpatents

    Powell, Howard T.; Riley, Michael O.; Wolfe, Charles R.; Lyon, Richard E.; Campbell, John H.; Jessop, Edward S.; Murray, James E.

    1989-01-01

    Large neodymium glass laser disks for disk amplifiers such as those used in the Nova laser require an edge cladding which absorbs at 1 micrometer. This cladding prevents edge reflections from causing parasitic oscillations which would otherwise deplete the gain. Nova now utilizes volume-absorbing monolithic-glass claddings which are fused at high temperature to the disks. These perform quite well but are expensive to produce. Absorbing glass strips are adhesively bonded to the edges of polygonal disks using a bonding agent whose index of refraction matches that of both the laser and absorbing glass. Optical finishing occurs after the strips are attached. Laser disks constructed with such claddings have shown identical gain performance to the previous Nova disks and have been tested for hundreds of shots without significant degradation.

  12. Composite polymer: Glass edge cladding for laser disks

    DOEpatents

    Powell, H.T.; Wolfe, C.A.; Campbell, J.H.; Murray, J.E.; Riley, M.O.; Lyon, R.E.; Jessop, E.S.

    1987-11-02

    Large neodymium glass laser disks for disk amplifiers such as those used in the Nova laser require an edge cladding which absorbs at 1 micrometer. This cladding prevents edge reflections from causing parasitic oscillations which would otherwise deplete the gain. Nova now utilizes volume-absorbing monolithic-glass claddings which are fused at high temperature to the disks. These perform quite well but are expensive to produce. Absorbing glass strips are adhesively bonded to the edges of polygonal disks using a bonding agent whose index of refraction matches that of both the laser and absorbing glass. Optical finishing occurs after the strips are attached. Laser disks constructed with such claddings have shown identical gain performance to the previous Nova disks and have been tested for hundreds of shots without significant degradation. 18 figs.

  13. View of building 11050, showing metal clad addition on east ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of building 11050, showing metal clad addition on east elevation, looking southwest. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Machine Shop, C Street, China Lake, Kern County, CA

  14. High Resolution Temperature Estimation During Laser Cladding of Stainless Steel

    NASA Astrophysics Data System (ADS)

    Devesse, Wim; De Baere, Dieter; Hinderdael, Michaël; Guillaume, Patrick

    Laser cladding is a technique that is used for the coating, repair and production of metallic parts. Material is added to the surface of the part by injecting a flow of powder into a melt pool that is created with a high power laser beam. When the beam scans the surface of the substrate, strong local heating and cooling results. A good knowledge of the temperature distribution history during the laser cladding process is vital to predict and optimize the material properties of the final part. This paper presents a contactless temperature measurement system with high temporal and spatial resolution based on a hyperspectral line camera. High temperature measurements were made during laser cladding of AISI 316L stainless steel. A good correlation is shown between the temperature measurements and microscope images taken after creation of the clad.

  15. Oxidation during reflood of reactor core with melting cladding

    SciTech Connect

    Siefken, L.J.; Allison, C.M.; Davis, K.L.

    1995-09-01

    Models were recently developed and incorporated into the SCDAP/RELAP5 code for calculating the oxidation of fuel rods during cladding meltdown and reflood. Experiments have shown that a period of intense oxidation may occur when a hot partially oxidized reactor core is reflooded. This paper offers an explanation of the cladding meltdown and oxidation processes that cause this intense period of oxidation. Models for the cladding meltdown and oxidation processes are developed. The models are assessed by simulating a severe fuel damage experiment that involved reflood. The models for cladding meltdown and oxidation were found to improve calculation of the temperature and oxidation of fuel rods during the period in which hot fuel rods are reflooded.

  16. High temperature solar selective absorber coating deposited by laser cladding

    NASA Astrophysics Data System (ADS)

    Pang, Xuming

    2017-09-01

    In order to prepare high temperature stability cermets solar selective absorbing coating, single- layer Ni/Mo–TiC cermets coatings were firstly deposited on stainless steel substrate using laser cladding method and surface coating method. The result shows that the performance of the laser cladding coating is far superior to the coating fabricated by the surface coating method with thermal emittance decreased from 44.6% to 5.5%. Furthermore, the spectrally selective coating fabricated by laser cladding shows the excellent thermal stability. The solar absorptance and thermal emittance of the coating are 80.7% and 6.0% at 600 °C, 80% and 5.5% at room temperature, respectively. This result indicates that TiC-based cermets are more propitious solar selective absorber materials. More importantly, laser cladding, as a representative of new techniques, could be applied to the field of the solar selective absorber coating.

  17. Neutron-induced helium implantation in GCFR cladding

    SciTech Connect

    Yamada, H.; Poeppel, R. B.; Sevy, R. H.

    1980-10-01

    The neutron-induced implantation of helium atoms on the exterior surfaces of the cladding of a prototypic gas-cooled fast reactor (GCFR) has been investigated analytically. A flux of recoil helium particles as high as 4.2 x 10/sup 10/ He/cm/sup 2/.s at the cladding surface has been calculated at the peak power location in the core of a 300-MWe GCFR. The calculated profile of the helium implantation rates indicates that although some helium is implanted as deep as 20 ..mu..m, more than 99% of helium particles are implanted in the first 2-..mu..m-deep layer below the cladding surface. Therefore, the implanted helium particles should mainly affect surface properties of the GCFR cladding.

  18. Young's modulus anisotropy in reactor pressure vessel cladding

    NASA Astrophysics Data System (ADS)

    Vandermeulen, W.; Mertens, M.; Scibetta, M.

    2012-02-01

    In a previous study it was shown that the anisotropy of Young's modulus in the stainless steel cladding of a reactor pressure vessel could be attributed to the solidification texture of the cladding. Further it was found that annealing the samples to remove the delta phase caused a modulus change but only in some directions. Since the texture was only estimated from X-ray diffraction patterns the moduli, calculated for some principal directions, differed considerably from the measured ones. In the present study, executed on a practically identical cladding, the texture was determined by actual texture measurements. It was found to be close to a fibre texture with <0 0 1> perpendicular to the cladding plane and the values calculated from it agreed much better with the experimental ones. The annealing effect found in the previous study was shown to be due to surface recrystallization induced by milling damage.

  19. Mechanical properties of irradiated fast breeder reactor cladding and ducts

    SciTech Connect

    Johnson, G.D.; Hunter, C.W.

    1983-02-01

    Austenitic stainless steels are being used for various core components in Liquid Metal Fast Breeder Reactors. Twenty percent cold worked Type 316 stainless steel is being used for both fuel pin cladding and ducts in the Fast Flux Test Facility. Safe and reliable operation of breeder reactors requires a characterization of the effects of fast neutron irradiation and environment on the mechanical properties of the cladding and duct material. Nearly 1400 tests have been conducted on unirradiated and irradiated cladding and duct samples under conditions relevant to reactor operational and transient events. Six different types of tests conducted on cladding and duct samples are described and the effects of irradiation on the properties are discussed.

  20. High Temperature Steam Corrosion of Cladding for Nuclear Applications: Experimental

    SciTech Connect

    McHugh, Kevin M; Garnier, John E; Sergey Rashkeev; Michael V. Glazoff; George W. Griffith; Shannong M. Bragg-Sitton

    2013-01-01

    Stability of cladding materials under off-normal conditions is an important issue for the safe operation of light water nuclear reactors. Metals, ceramics, and metal/ceramic composites are being investigated as substitutes for traditional zirconium-based cladding. To support down-selection of these advanced materials and designs, a test apparatus was constructed to study the onset and evolution of cladding oxidation, and deformation behavior of cladding materials, under loss-of-coolant accident scenarios. Preliminary oxidation tests were conducted in dry oxygen and in saturated steam/air environments at 1000OC. Tube samples of Zr-702, Zr-702 reinforced with 1 ply of a ß-SiC CMC overbraid, and sintered a-SiC were tested. Samples were induction heated by coupling to a molybdenum susceptor inside the tubes. The deformation behavior of He-pressurized tubes of Zr-702 and SiC CMC-reinforced Zr-702, heated to rupture, was also examined.

  1. Jet slurry erosion performance of composite clad and its characterization

    NASA Astrophysics Data System (ADS)

    B, Lohit R.; Horakeri, Gururaj S.; Bhovi, Prabakhar M.

    2016-09-01

    In the present work, development of composite cladding consists of Cr23C6 (chromium carbide) as reinforcement particles 20 wt. % in Ni-based matrix 80 wt. % on austenitic stainless steel through exposure of microwave radiation has been carried out. The jet slurry erosion test was performed on microwave composite clad. The functional performance of composite clad has been evaluated for different parametric conditions like varying impingement velocity and impact angle. The increasing weight loss trend was observed with time for the first 30 min. after that the individual trend decreased; at high impingement velocity and maximum impact angle. SEM micrographs of eroded clad samples at various impact angle and impingement velocity were discussed. The maximum weight loss occurred at 90° angle and velocity of 60 m/s, and minimum at 30° angle and velocity of 20 m/s.

  2. DISK PUMP FEASIBILITY INVESTIGATION,

    DTIC Science & Technology

    The disk pump was investigated at the Air Force Rocket Propulsion Laboratory (AFRPL) to determine the feasibility of using a novel viscous pumping... pump primarily for application as an inducer. The disk pump differs drastically from conventional pumps because of the following major factors: (1) The...The pump inlet relative velocity is equal only to the through flow velocity between the disks. Therefore, there is good indication that the disk pump will

  3. Double-clad nuclear-fuel safety rod

    DOEpatents

    McCarthy, W.H.; Atcheson, D.B.

    1981-12-30

    A device for shutting down a nuclear reactor during an undercooling or overpower event, whether or not the reactor's scram system operates properly. This is accomplished by double-clad fuel safety rods positioned at various locations throughout the reactor core, wherein melting of a secondary internal cladding of the rod allows the fuel column therein to shift from the reactor core to place the reactor in a subcritical condition.

  4. Neutron-absorbing amorphous alloys for cladding coatings

    NASA Astrophysics Data System (ADS)

    Sevryukov, O. N.; Fedotov, V. T.; Polyansky, A. A.

    2016-04-01

    This paper shows developed compositions of neutron-absorbing cladding alloys based on nickel and containing such elements as B, Gd, Hf, and Mn. The techniques for application of coatings from these alloys on the surface of structural steels have been improved. It has been shown that the amorphous neutron-absorbing coating is more uniform than the crystalline one. The experimental data on the adhesion of cladding coatings with a steel substrate and their neutron-absorbing capacity have been obtained.

  5. Review of cladding-coolant interactions during LWR accident transients

    SciTech Connect

    Hobson, D.O.

    1980-01-01

    Some of the coolant-cladding interactions that can take place during the design basis loss-of-coolant accident and the Three Mile Island loss-of-coolant accident are analyzed. The physical manifestations of the interactions are quite similar, but the time sequences involved can cause very different end results. These results are described and a listing is given of the main research programs that are involved in coolant-cladding interaction research.

  6. Explosion Clad for Upstream Oil and Gas Equipment

    SciTech Connect

    Banker, John G.; Massarello, Jack; Pauly, Stephane

    2011-01-17

    Today's upstream oil and gas facilities frequently involve the combination of high pressures, high temperatures, and highly corrosive environments, requiring equipment that is thick wall, corrosion resistant, and cost effective. When significant concentrations of CO{sub 2} and/or H{sub 2}S and/or chlorides are present, corrosion resistant alloys (CRA) can become the material of choice for separator equipment, piping, related components, and line pipe. They can provide reliable resistance to both corrosion and hydrogen embrittlement. For these applications, the more commonly used CRA's are 316L, 317L and duplex stainless steels, alloy 825 and alloy 625, dependent upon the application and the severity of the environment. Titanium is also an exceptional choice from the technical perspective, but is less commonly used except for heat exchangers. Explosion clad offers significant savings by providing a relatively thin corrosion resistant alloy on the surface metallurgically bonded to a thick, lower cost, steel substrate for the pressure containment. Developed and industrialized in the 1960's the explosion cladding technology can be used for cladding the more commonly used nickel based and stainless steel CRA's as well as titanium. It has many years of proven experience as a reliable and highly robust clad manufacturing process. The unique cold welding characteristics of explosion cladding reduce problems of alloy sensitization and dissimilar metal incompatibility. Explosion clad materials have been used extensively in both upstream and downstream oil, gas and petrochemical facilities for well over 40 years. The explosion clad equipment has demonstrated excellent resistance to corrosion, embrittlement and disbonding. Factors critical to insure reliable clad manufacture and equipment design and fabrication are addressed.

  7. Supercontinuum Generation in a Microstructured Fiber with an Irregular Cladding

    NASA Astrophysics Data System (ADS)

    Minkovich, V. P.; Sotsky, A. B.; Vaca Pereira G., M.; Dzen, I. S.; Sotskaya, L. I.

    2016-05-01

    A broad-band supercontinuum generation was obtained at excitation of a microstructured optical fiber with an irregular cladding by femtosecond laser pulses. To explain the experimental data, calculations of the mode characteristics of microstructured fibers were performed. It was shown that the creation of air channels with different radii in the fiber cladding makes it possible to involve both the fundamental and high fiber modes in the supercontinuum generation that helps to increase the width of the generation spectrum.

  8. Optimization of Laser Cladding for Al Coating Production

    NASA Astrophysics Data System (ADS)

    Riveiro, A.; Mejías, A.; Lusquiños, F.; del Val, J.; Comesaña, R.; Pardo, J.; Pou, J.

    The production of aluminum based coatings on a stainless steel (AISI 304) substrate by side laser cladding, and using a high power diode laser was experimentally studied. Relevant processing parameters were found and correlations between them were determined. Furthermore, the influence of the processing parameters on the costs associated to the process was examined. These relationships can be used as a guideline for the selection of proper processing parameters for laser cladding of this kind of materials.

  9. Multiple-cladding fibers with reduced bend loss

    NASA Astrophysics Data System (ADS)

    Tomljenovic-Hanic, Snjezana; Bulla, Douglas A. P.; Ankiewicz, Adrian; Love, John D.; Bailey, Ron

    2007-04-01

    We demonstrate that a highly bend-resistant fiber can be realized. It is shown theoretically that, by introducing both depressed and elevated rings into the cladding, bending loss can be reduced significantly. A fiber based on this design has been fabricated and characterized as a first step toward achieving this goal. The results show that a multiple-cladding fiber is highly bend resistant when compared with the standard telecom single-mode fiber.

  10. Material development for thermionic fuel-cladding systems.

    NASA Technical Reports Server (NTRS)

    Yang, L.; Hudson, R. G.; Johnson, H.; Horner, H.; Allen, D. T.

    1972-01-01

    Fuel-cladding systems capable of maintaining stable dimension and electron emission characteristics at high temperatures under irradiation are essential to the successful operation of nuclear thermionic power sources. Studies regarding two possible systems, involving tungsten clad uranium carbide and uranium oxide, are considered. Out-of-pile developmental efforts and the in-pile evaluation results for the two systems are described. Prototypical emitters have been tested for 8000 hours for the carbide system and 4000 hours for the oxide system.

  11. Properties of multilayer coatings produced by coaxial laser cladding

    NASA Astrophysics Data System (ADS)

    Petrovskiy, V. N.; Bykovskiy, D. P.; Dzhumaev, P. S.; Polskiy, V. I.; Prokopova, N. M.; Chirikov, S. N.

    2016-09-01

    This article contains results of the study of multilayer coatings produced by laser cladding on the substrate steel 34HMA using iron based powder PR-10R6M5 as the filler material. The coatings were produced with consistent application of the tracks with fixed overlapping. The dependencies between the characteristics of tracks and the technological mode of deposition were revealed. Properties of coatings were determined for various overlapping of tracks and directions of the cladding layers.

  12. Thermocapillary-induced breakup of molten cladding films

    SciTech Connect

    Henkel, P.R.

    1987-06-01

    The fragmentation of molten cladding films into rivulets and single waves is investigated. This problem is especially relevant to liquid-metal fast breeder reactor safety analysis because of its impact on the flow regime of the clad metal. Among other effects, various instabilities may contribute to film breakup. In the axial direction, the Kelvin-Helmholtz instability can arise. As the Sandia transient axial relocation experiments frequently exhibit, an azimuthal fragmentation process also occurs. Consequently, another instability due to thermocapillarity is proposed.

  13. Well pump

    SciTech Connect

    Page, J.S.

    1983-03-08

    Well fluid pumping apparatus comprises: (A) body structure defining an upright plunger bore, (B) a plunger reciprocable in that bore, (C) the body structure also defining a chamber sidewardly offset from an axis defined by the plunger bore and communicating with the bore, and (D) valving carried by the body structure to pass intake fluid via the chamber into the plunger bore in response to stroking of the plunger in one direction in the bore, and to pass discharge fluid from the plunger bore into and from the chamber in response to stroking of the plunger in the opposite direction in the bore.

  14. Well pump

    DOEpatents

    Ames, Kenneth R.; Doesburg, James M.

    1987-01-01

    A well pump includes a piston and an inlet and/or outlet valve assembly of special structure. Each is formed of a body of organic polymer, preferably PTFE. Each includes a cavity in its upper portion and at least one passage leading from the cavity to the bottom of the block. A screen covers each cavity and a valve disk covers each screen. Flexible sealing flanges extend upwardly and downwardly from the periphery of the piston block. The outlet valve block has a sliding block and sealing fit with the piston rod.

  15. High-power and highly efficient Tm3+-doped silica fiber lasers pumped with diode lasers operating at 1150 nm.

    PubMed

    Jackson, Stuart D; Bugge, Frank; Erbert, Götz

    2007-10-01

    An output power of 1.74 W at 2.03 microm was generated at a slope efficiency of 51% when a double-clad Tm(3+)-doped silica fiber laser was pumped with high-power 1150 nm diode lasers. Pump excited state absorption from the upper laser level populates higher energy levels allowing cross relaxation to repopulate the upper laser level at a quantum efficiency greater than unity and to limit losses relating to additional pump excited state absorption. The output power was scaled to 4.77 W when both ends of the fiber were pumped.

  16. Glass-clad semiconductor core optical fibers

    NASA Astrophysics Data System (ADS)

    Morris, Stephanie Lynn

    Glass-clad optical fibers comprising a crystalline semiconductor core have garnered considerable recent attention for their potential utility as novel waveguides for applications in nonlinear optics, sensing, power delivery, and biomedicine. As research into these fibers has progressed, it has become evident that excessive losses are limiting performance and so greater understanding of the underlying materials science, coupled with advances in fiber processing, is needed. More specifically, the semiconductor core fibers possess three performance-limiting characteristics that need to be addressed: (a) thermal expansion mismatches between crystalline core and glass cladding that lead to cracks, (b) the precipitation of oxide species in the core upon fiber cooling, which results from partial dissolution of the cladding glass by the core melt, and (c) polycrystallinity; all of which lead to scattering and increased transmission losses. This dissertation systematically studies each of these effects and develops both a fundamental scientific understanding of and practical engineering methods for reducing their impact. With respect to the thermal expansion mismatch and, in part, the dissolution of oxides, for the first time to our knowledge, oxide and non-oxide glass compositions are developed for a series of semiconductor cores based on two main design criteria: (1) matching the thermal expansion coefficient between semiconductor core and glass cladding to minimize cracking and (2) matching the viscosity-temperature dependences, such that the cladding glass draws into fiber at a temperature slightly above the melting point of the semiconductor in order to minimize dissolution and improve the fiber draw process. The x[Na 2O:Al2O3] + (100 - 2x)SiO2 glass compositional family was selected due to the ability to tailor the glass properties to match the aforementioned targets through slight variations in composition and adjusting the ratios of bridging and non-bridging oxygen

  17. HIP clad nickel base Alloy 625 for deep sour wells

    SciTech Connect

    Uhl, W.K.; Pendley, M.R.

    1984-05-01

    The hot isostatic pressing (HIP) process was used to clad nickel base Alloy 625 to AISI 4130 low alloy steel. The performance of the HIP clad material in the corrosive environment characteristic of deep, sour oil and gas wells was evaluated in laboratory tests. Included in the test program were NACE TM-01-77 sulfide stress cracking tests, chloride stress corrosion cracking tests in boiling MgCl /SUB 2'/ , and pitting and crevice corrosion tests. The HIP clad 625 performed excellently, displaying essentially the same corrosion resistance as wrought 625. Specifically the HIP clad 625 resisted sulfide stress cracking at applied stresses as high as 120% of yield strength and resisted chloride stress corrosion cracking at stresses exceeding 100% of yield. The HIP clad 625 also displayed immunity to pitting and crevice corrosion, with corrosion rates of <0.025 mm/y (1 mil/y). The 4130 base metal, however, was attacked severly in all tests. SEM/EDX analysis of the 625/4130 interface demonstrated that dilution of the cladding by the base metal was essentially eliminated.

  18. Fuel clad chemical interactions in fast reactor MOX fuels

    NASA Astrophysics Data System (ADS)

    Viswanathan, R.

    2014-01-01

    Clad corrosion being one of the factors limiting the life of a mixed-oxide fast reactor fuel element pin at high burn-up, some aspects known about the key elements (oxygen, cesium, tellurium, iodine) in the clad-attack are discussed and many Fuel-Clad-Chemical-Interaction (FCCI) models available in the literature are also discussed. Based on its relatively superior predictive ability, the HEDL (Hanford Engineering Development Laboratory) relation is recommended: d/μm = ({0.507 ṡ [B/(at.% fission)] ṡ (T/K-705) ṡ [(O/M)i-1.935]} + 20.5) for (O/M)i ⩽ 1.98. A new model is proposed for (O/M)i ⩾ 1.98: d/μm = [B/(at.% fission)] ṡ (T/K-800)0.5 ṡ [(O/M)i-1.94] ṡ [P/(W cm-1)]0.5. Here, d is the maximum depth of clad attack, B is the burn-up, T is the clad inner surface temperature, (O/M)i is the initial oxygen-to-(uranium + plutonium) ratio, and P is the linear power rating. For fuels with [n(Pu)/n(M = U + Pu)] > 0.25, multiplication factors f are recommended to consider the potential increase in the depth of clad-attack.

  19. Uranium and cesium diffusion in fuel cladding of electrogenerating channel

    SciTech Connect

    Vasil’ev, I. V. Ivanov, A. S.; Churin, V. A.

    2014-12-15

    The results of reactor tests of a carbonitride fuel in a single-crystal cladding from a molybdenum-based alloy can be used in substantiating the operational reliability of fuels in developing a project of a megawatt space nuclear power plant. The results of experimental studies of uranium and cesium penetration into the single-crystal cladding of fuel elements with a carbonitride fuel are interpreted. Those fuel elements passed nuclear power tests in the Ya-82 pilot plant for 8300 h at a temperature of about 1500°C. It is shown that the diffusion coefficients for uranium diffusion into the cladding are virtually coincident with the diffusion coefficients measured earlier for uranium diffusion into polycrystalline molybdenum. It is found that the penetration of uranium into the cladding is likely to occur only in the case of a direct contact between the cladding and fuel. The experimentally observed nonmonotonic uranium-concentration profiles are explained in terms of predominant uranium diffusion along grain boundaries. It is shown that a substantially nonmonotonic behavior observed in our experiment for the uranium-concentration profile may be explained by the presence of a polycrystalline structure of the cladding in the surface region from its inner side. The diffusion coefficient is estimated for the grain-boundary diffusion of uranium. The diffusion coefficients for cesium are estimated on the basis of experimental data obtained in the present study.

  20. Real-time laser cladding control with variable spot size

    NASA Astrophysics Data System (ADS)

    Arias, J. L.; Montealegre, M. A.; Vidal, F.; Rodríguez, J.; Mann, S.; Abels, P.; Motmans, F.

    2014-03-01

    Laser cladding processing has been used in different industries to improve the surface properties or to reconstruct damaged pieces. In order to cover areas considerably larger than the diameter of the laser beam, successive partially overlapping tracks are deposited. With no control over the process variables this conduces to an increase of the temperature, which could decrease mechanical properties of the laser cladded material. Commonly, the process is monitored and controlled by a PC using cameras, but this control suffers from a lack of speed caused by the image processing step. The aim of this work is to design and develop a FPGA-based laser cladding control system. This system is intended to modify the laser beam power according to the melt pool width, which is measured using a CMOS camera. All the control and monitoring tasks are carried out by a FPGA, taking advantage of its abundance of resources and speed of operation. The robustness of the image processing algorithm is assessed, as well as the control system performance. Laser power is decreased as substrate temperature increases, thus maintaining a constant clad width. This FPGA-based control system is integrated in an adaptive laser cladding system, which also includes an adaptive optical system that will control the laser focus distance on the fly. The whole system will constitute an efficient instrument for part repair with complex geometries and coating selective surfaces. This will be a significant step forward into the total industrial implementation of an automated industrial laser cladding process.

  1. Parameter Optimization for Mould and Die Recovering Using Laser Cladding

    NASA Astrophysics Data System (ADS)

    Tabernero, I.; Lamikiz, A.; Ukar, E.; Arregi, B.; Figueras, J.; Soriano, C.

    2009-11-01

    In the last years the laser cladding has become an important technology that has been studied by several industries as automotive or aeronautical. Therefore, although this technology was used initially for coatings, actually it is being used for repairing or even direct manufacturing of high added value parts. In this paper, the application of laser cladding for repairing a GGG70L stamping die is presented. The first step is to present the methodology used to obtain the optimum conditions for AISI 316L stainless steel clads on structural steel (DIN C45). The next section shows a deeper study about the capacity of the process to fill standard geometries on DIN C45 and DIN 1.2379. Finally, a nodular cast iron GGG70L stamping die is repaired using laser cladding process. The parameters and strategy used for the repairing have been obtained on previous sections. Furthermore, in the final section a powder concentration model is presented as the first step to create a complete model that simulate the three stages of laser cladding: interaction between powder and laser beam, creation of melt pool and generation of clad geometry.

  2. Hollow cylindrical plasma filament waveguide with discontinuous finite thickness cladding

    SciTech Connect

    Alshershby, Mostafa; Hao Zuoqiang; Lin Jingquan

    2013-01-15

    We have explored here a hollow cylindrical laser plasma multifilament waveguide with discontinuous finite thickness cladding, in which the separation between individual filaments is in the range of several millimeters and the waveguide cladding thickness is in the order of the microwave penetration depth. Such parameters give a closer representation of a realistic laser filament waveguide sustained by a long stable propagation of femtosecond (fs) laser pulses. We report how the waveguide losses depend on structural parameters like normalized plasma filament spacing, filament to filament distance or pitch, normal spatial frequency, and radius of the plasma filament. We found that for typical plasma parameters, the proposed waveguide can support guided modes of microwaves in extremely high frequency even with a cladding consisting of only one ring of plasma filaments. The loss of the microwave radiation is mainly caused by tunneling through the discontinuous finite cladding, i.e., confinement loss, and is weakly dependent on the plasma absorption. In addition, the analysis indicates that the propagation loss is fairly large compared with the loss of a plasma waveguide with a continuous infinite thickness cladding, while they are comparable when using a cladding contains more than one ring. Compared to free space propagation, this waveguide still presents a superior microwave transmission to some distance in the order of the filamentation length; thus, the laser plasma filaments waveguide may be a potential channel for transporting pulsed-modulated microwaves if ensuring a long and stable propagation of fs laser pulses.

  3. Residual Stress Measurements of Explosively Clad Cylindrical Pressure Vessels

    SciTech Connect

    Taylor, Douglas J; Watkins, Thomas R; Hubbard, Camden R; Hill, M. R.; Meith, W. A.

    2012-01-01

    Tantalum refractory liners were explosively clad into cylindrical pressure vessels, some of which had been previously autofrettaged. Using explosive cladding, the refractory liner formed a metallurgical bond with the steel of the pressure vessel at a cost of induced strain. Two techniques were employed to determine the residual stress state of the clad steel cylinders: neutron diffraction and mechanical slitting. Neutron diffraction is typically nondestructive; however, due to attenuation along the beam path, the cylinders had to be sectioned into rings that were nominally 25 mm thick. Slitting is a destructive method, requiring the sectioning of the cylindrical samples. Both techniques provided triaxial stress data and useful information on the effects of explosive cladding. The stress profiles in the hoop and radial directions were similar for an autofrettaged, nonclad vessel and a clad, nonautofrettaged vessel. The stress profiles in the axial direction appeared to be different. Further, the data suggested that residual stresses from the autofrettage and explosive cladding processes were not additive, in part due to evidence of reverse yielding. The residual stress data are presented, compared and discussed.

  4. Laser cladding: repairing and manufacturing metal parts and tools

    NASA Astrophysics Data System (ADS)

    Sexton, Leo

    2003-03-01

    Laser cladding is presently used to repair high volume aerospace, automotive, marine, rail or general engineering components where excessive wear has occurred. It can also be used if a one-off high value component is either required or has been accidentally over-machined. The ultimate application of laser cladding is to build components up from nothing, using a laser cladding system and a 3D CAD drawing of the component. It is thus emerging that laser cladding can be classified as a special case of Rapid Prototyping (RP). Up to this point in time RP was seen, and is still seen, as in intermediately step between the design stage of a component and a finished working product. This can now be extended so that laser cladding makes RP a one-stop shop and the finished component is made from tool-steel or some alloy-base material. The marriage of laser cladding with RP is an interesting one and offers an alternative to traditional tool builders, re-manufacturers and injection mould design/repair industries. The aim of this paper is to discuss the emergence of this new technology, along with the transference of the process out of the laboratory and into the industrial workplace and show it is finding its rightful place in the manufacturing/repair sector. It will be shown that it can be used as a cost cutting, strategic material saver and consequently a green technology.

  5. Fiber-laser pumped actively Q-switched Er:LuYAG laser at 1648 nm

    NASA Astrophysics Data System (ADS)

    Yang, X. F.; Wang, Y.; Zhao, T.; Zhu, H. Y.; Shen, D. Y.

    2016-02-01

    We demonstrated an acousto-optic Q-switched 1648 nm Er:LuYAG laser resonantly pumped by a cladding-pumped Er,Yb fiber laser at 1532 nm. Stable Q-switching operation was obtained with the pulse repetition rate (PRR) varying from 200 Hz to 10 kHz. At PRR of 200 Hz, the laser yielded Q-switched pulses with 3.3 mJ pulse energy and 65 ns pulse duration, corresponding to a peak power of 50.7 kW for 10.4 W of incident pump power.

  6. Swelling clad-type plastic optical fiber alkane sensor with multi-layer cladding using electrospray deposition method

    NASA Astrophysics Data System (ADS)

    Nakamura, Akira; Suzuki, Yutaka; Morisawa, Masayuki

    2017-04-01

    In this study, we develop a plastic optical fiber (POF) sensor with a double-layer structure cladding consisting of a swelling polymer lower layer and a dye-doped swelling polymer upper layer. Both cladding layers swell and decrease their refractive indices when exposed to alkane vapor. Then, the structure of the POF sensor changes from leaky to waveguide mode. Therefore, the intensity of transmitted light changes remarkably, depending on the presence of alkane. The absorption of light due to the dye in the upper cladding layer increases the change in transmitted light intensity. In this study, we fabricated a POF sensor by using the electrospray deposition method and examined its response to alkane vapor. The results indicate an improvement in the sensitivity of the POF alkane sensor due to the effect of the double-clad layer.

  7. Pump apparatus

    SciTech Connect

    Kime, J.A.

    1987-02-17

    This patent describes a gas-oil well production system for pumping formation fluid wherein a down hole pump is provided having a barrel including a barrel fluid inlet, a barrel fluid outlet, a barrel chamber, and a plunger mounted in the barrel chamber having a plunger chamber. The plunger is reciprocally driven between an upper terminal position at the end of the plunger upstroke and a lower terminal position at the end of the plunger downstroke. The method for removing developed gaseous fluids in the formation fluid from the barrel chamber comprises: drawing formation fluid into the barrel chamber during the plunger upstroke; providing gas port means in the barrel; expelling the developed gaseous fluids from the barrel chamber through the gas port means during the occurrence of that portion of the plunger downstroke from the upper terminal position of the gas port means; and substantially blocking the gas port means and moving formation fluid into the plunger chamber during the occurrence of that portion of the plunger downstroke from below the gas port means to the lower terminal position.

  8. Power scaling from buried depressed-cladding waveguides realized in Nd:YVO4 by femtosecond-laser beam writing

    NASA Astrophysics Data System (ADS)

    Salamu, Gabriela; Pavel, Nicolaie

    2016-10-01

    We report on output power performances obtained by diode-laser pumping of buried cladding-waveguides that were inscribed with a femtosecond-laser beam writing technique in several Nd:YVO4 media. Continuous-wave output power of 3.4 W at 1.06 μm for an absorbed pump power at 808 nm of 10.3 W was obtained from a circular waveguide of 100-μm diameter that was realized in a 6.9-mm long, 0.5-at% Nd:YVO4 crystal; the slope efficiency with respect to the absorbed pump power was 0.36. The pump at 880 nm, directly into the 4F3/2 emitting level, was used to improve the waveguide output characteristics. With an absorbed pump power of 9.8 W at 880 nm, the same waveguide yielded 4.4 W at 1.06 μm, whereas for emission at 1.34 μm the output power reached 1.7 W; the slope efficiency improved to 0.47 for laser emission at 1.06 μm and reached 0.24 for operation at 1.34 μm. Results recorded from similar waveguides that were inscribed in 0.7-at% Nd:YVO4 and 1.0-at% Nd:YVO4 crystals are presented.

  9. Cladding Attachment Over Thick Exterior Insulating Sheathing

    SciTech Connect

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1.What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2.Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3.What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  10. Weld overlay cladding with iron aluminides

    SciTech Connect

    Goodwin, G.M.

    1997-12-01

    The author has established a range of compositions for these alloys within which hot cracking resistance is very good, and within which cold cracking can be avoided in many instances by careful control of welding conditions, particularly preheat and postweld heat treatment. For example, crack-free butt welds have been produced for the first time in 12-mm thick wrought Fe{sub 3}Al plate. Cold cracking, however, still remains an issue in many cases. The author has developed a commercial source for composite weld filler metals spanning a wide range of achievable aluminum levels, and are pursuing the application of these filler metals in a variety of industrial environments. Welding techniques have been developed for both the gas tungsten arc and gas metal arc processes, and preliminary work has been done to utilize the wire arc process for coating of boiler tubes. Clad specimens have been prepared for environmental testing in-house, and a number of components have been modified and placed in service in operating kraft recovery boilers. In collaboration with a commercial producer of spiral weld overlay tubing, the author is attempting to utilize the new filler metals for this novel application.

  11. Cladding Attachment Over Thick Exterior Insulating Sheathing

    SciTech Connect

    Baker, P.; Eng, P.; Lepage, R.

    2014-01-01

    The addition of insulation to the exterior of buildings is an effective means of increasing the thermal resistance of both wood framed walls as well as mass masonry wall assemblies. For thick layers of exterior insulation (levels greater than 1.5 inches), the use of wood furring strips attached through the insulation back to the structure has been used by many contractors and designers as a means to provide a convenient cladding attachment location (Straube and Smegal 2009, Pettit 2009, Joyce 2009, Ueno 2010). The research presented in this report is intended to help develop a better understanding of the system mechanics involved and the potential for environmental exposure induced movement between the furring strip and the framing. BSC sought to address the following research questions: 1. What are the relative roles of the mechanisms and the magnitudes of the force that influence the vertical displacement resistance of the system? 2. Can the capacity at a specified deflection be reliably calculated using mechanics based equations? 3. What are the impacts of environmental exposure on the vertical displacement of furring strips attached directly through insulation back to a wood structure?

  12. Diode edge-pumped passively Q-switched microchip laser

    NASA Astrophysics Data System (ADS)

    Kong, Weipeng; Tsunekane, Masaki; Taira, Takunori

    2015-09-01

    There is an increasing demand for high-intensity subnanosecond lasers for emerging industrial applications. While femtosecond and picosecond laser sources are considered promising, they suffer from the significant drawbacks of increased complexity and cost. In this regard, we demonstrate a unique edge-pumped passively Q-switched Nd∶YAG/Cr4+∶YAG microchip laser. The microchip is made of a Nd∶YAG/Sm∶YAG composite ceramic, and a Sm∶YAG cladding is utilized as both the pump beam waveguide and amplified spontaneous emission absorber. With the use of a flat-concave laser cavity, we obtain single-pulse energy of 1.66 mJ for an absorbed pump energy of 24 mJ. Further, the resulting pulse width is 683 ps, and the repetition rate is 10 Hz.

  13. High-efficiency, 154  W CW, diode-pumped Raman fiber laser with brightness enhancement.

    PubMed

    Glick, Yaakov; Fromzel, Viktor; Zhang, Jun; Ter-Gabrielyan, Nikolay; Dubinskii, Mark

    2017-01-20

    We demonstrate a high-power, high-efficiency Raman fiber laser pumped directly by laser diode modules at 978 nm. 154 W of CW power were obtained at a wavelength of 1023 nm with an optical to optical efficiency of 65%. A commercial graded-index (GRIN) core fiber acts as the Raman fiber in a power oscillator configuration, which includes spectral selection to prevent generation of the second Stokes. In addition, brightness enhancement of the pump beam by a factor of 8.4 is attained due to the Raman gain distribution profile in the GRIN fiber. To the best of our knowledge this is the highest power and highest efficiency Raman fiber laser demonstrated in any configuration allowing brightness enhancement (i.e., in either cladding-pumped configuration or with GRIN fibers, excluding step-index core pumped), regardless of pumping scheme (i.e., either diode pumped or fiber laser pumped).

  14. LMFBR with booster pump in pumping loop

    DOEpatents

    Rubinstein, H.J.

    1975-10-14

    A loop coolant circulation system is described for a liquid metal fast breeder reactor (LMFBR) utilizing a low head, high specific speed booster pump in the hot leg of the coolant loop with the main pump located in the cold leg of the loop, thereby providing the advantages of operating the main pump in the hot leg with the reliability of cold leg pump operation.

  15. Winding for linear pump

    DOEpatents

    Kliman, G.B.; Brynsvold, G.V.; Jahns, T.M.

    1989-08-22

    A winding and method of winding for a submersible linear pump for pumping liquid sodium are disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet. 4 figs.

  16. Winding for linear pump

    DOEpatents

    Kliman, Gerald B.; Brynsvold, Glen V.; Jahns, Thomas M.

    1989-01-01

    A winding and method of winding for a submersible linear pump for pumping liquid sodium is disclosed. The pump includes a stator having a central cylindrical duct preferably vertically aligned. The central vertical duct is surrounded by a system of coils in slots. These slots are interleaved with magnetic flux conducting elements, these magnetic flux conducting elements forming a continuous magnetic field conduction path along the stator. The central duct has placed therein a cylindrical magnetic conducting core, this core having a cylindrical diameter less than the diameter of the cylindrical duct. The core once placed to the duct defines a cylindrical interstitial pumping volume of the pump. This cylindrical interstitial pumping volume preferably defines an inlet at the bottom of the pump, and an outlet at the top of the pump. Pump operation occurs by static windings in the outer stator sequentially conveying toroidal fields from the pump inlet at the bottom of the pump to the pump outlet at the top of the pump. The winding apparatus and method of winding disclosed uses multiple slots per pole per phase with parallel winding legs on each phase equal to or less than the number of slots per pole per phase. The slot sequence per pole per phase is chosen to equalize the variations in flux density of the pump sodium as it passes into the pump at the pump inlet with little or no flux and acquires magnetic flux in passage through the pump to the pump outlet.

  17. Liquid metal pump

    DOEpatents

    Pennell, William E.

    1982-01-01

    The liquid metal pump comprises floating seal rings and attachment of the pump diffuser to the pump bowl for isolating structural deflections from the pump shaft bearings. The seal rings also eliminate precision machining on large assemblies by eliminating the need for a close tolerance fit between the mounting surfaces of the pump and the seals. The liquid metal pump also comprises a shaft support structure that is isolated from the pump housing for better preservation of alignment of shaft bearings. The shaft support structure also allows for complete removal of pump internals for inspection and repair.

  18. Ion pump provides increased vacuum pumping speed

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Multiple-cell ion pumps with increased vacuum pumping speed are used for producing ultrahigh vacuums in vacuum tubes and mass spectrometers. The pump has eight cathode-anode magnetron cells arranged in a cylinder which increase the surface area of the cathode.

  19. Cladding Alloys for Fluoride Salt Compatibility Final Report

    SciTech Connect

    Muralidharan, Govindarajan; Wilson, Dane F; Santella, Michael L; Holcomb, David Eugene

    2011-05-01

    This interim report provides an overview of several candidate technologies for cladding nickel-based corrosion protection layers onto high-temperature structural alloys. The report also provides a brief overview of the welding and weld performance issues associated with joining nickel-clad nickel-based alloys. From the available techniques, two cladding technologies were selected for initial evaluation. The first technique is a line-of-sight method that would be useful for coating large structures such as vessel interiors or large piping. The line-of-sight method is a laser-based surface cladding technique in which a high-purity nickel powder mixed into a polymer binder is first sprayed onto the surface, baked, and then rapidly melted using a high power laser. The second technique is a vapor phase technique based on the nickel-carbonyl process that is suitable for coating inaccessible surfaces such as the interior surfaces of heat exchangers. The final project report will feature an experimental evaluation of the performance of the two selected cladding techniques.

  20. Optical monitoring of high power direct diode laser cladding

    NASA Astrophysics Data System (ADS)

    Liu, Shuang; Farahmand, Parisa; Kovacevic, Radovan

    2014-12-01

    Laser cladding is one of the most advanced surface modification techniques which can be used to build and repair high-value components. High power direct diode laser (HPDDL) offers unique quality and cost advantages over other lasers (CO2, Nd:YAG). Especially its rectangular laser beam with top-hat intensity distribution makes HPDDL an ideal tool for large area cladding. In order to utilize this technique successfully, the development of on-line monitoring and process control is necessary. In this study, an optical monitoring system consisting of a high-speed CCD camera, a pyrometer, and an infrared camera was used to analyze the mass- and heat-transfer in the cladding process. The particle transport in flight was viewed by a high-speed CCD camera; the interaction between powder flow and laser beam was observed by an infrared camera; and the thermal behavior of the molten pool was recorded by the pyrometer and the infrared camera. The effects of the processing parameters on the laser attenuation, particle heating and clad properties were investigated based on the obtained signals. The optical monitoring method improved the understanding about mutual interrelated phenomena in the cladding process.

  1. Hydraulic pump

    SciTech Connect

    Polak, P.R.; Jantzen, D.E.

    1984-05-15

    This invention relates to an improved pump jack characterized by a hollow piston rod which telescopes down over the sucker rod to which it is clamped for reciprocating motion. The cylinder, in turn, is fastened in fixed position directly to the upper exposed end of the well casing. As fluid is introduced into the lower end of the cylinder it raises the piston into engagement with a pushrod housed in the upper cylinder head that lifts switch-actuating means associated therewith into a position operative to actuate a switch located adjacent thereto thereby causing the latter to change state and actuate a multi-function solenoid valve so as to cut off fluid flow to the cylinder. As gravity lowers the sucker rod and piston exhausting the hydraulic fluid therebeneath, an adjustable stop engages the pushrod from above so as to return it together with the switch-actuating means associated therewith to their original positions thereby resetting the switch to complete the operating cycle.

  2. Broadband optical amplification with water-free hexagonal double-clad Bi doped silica fiber

    NASA Astrophysics Data System (ADS)

    Kobayashi, S.; Takahashi, M.; Ohara, M.; Kondo, I.; Fujii, Yusuke

    2016-03-01

    1.3 - 1.55 micron optical amplifiers for the long distance up-stream and down-stream networks for a future increase of fiber access networks in telecommunications are attractive. A bismuth-doped silica glass has a potential of the broadband spectrum as lasers and amplifier applications at 1.3 -1.55 micron. The bismuth-doped fiber lasers and amplifiers were discussed by the MOCVD method. In this report optical amplification characteristics at 1.3 - 1.55 micron are presented with the water free hexagonal double-clad bismuth-doped silica fiber (HDC-BDF) made by the vertical axial vapor-phase deposition (VAD) method. The bismuth and aluminum ions were vapor-phase doped into the silicon and germanium oxide. Pumping into the HDC-BDF was performed by using the tilt-polished fiber from the hexagonal surface with the multimode fiber pigtail of the pumping LD. 2 dB amplified gain was obtained with less than -40 dBm CW input signal power at 1310nm.

  3. Influence Of The Laser Cladding Strategies On The Mechanical Properties Of Inconel 718

    SciTech Connect

    Lamikiz, A.; Tabernero, I.; Ukar, E.; Lopez de Lacalle, L. N.

    2011-01-17

    This work presents different experimental results of the mechanical properties of Inconel registered 718 test parts built-up by laser cladding. Recently, turbine manufacturers for aeronautical sector have presented high interest on laser cladding processes. This process allows building fully functional structures on superalloys, such as Inconel registered 718, with high flexibility on complex shapes. However, there is limited data on mechanical properties of the laser cladding structures. Moreover, the available data do not include the influence of process parameters and laser cladding strategies. Therefore, a complete study of the influence of the laser cladding parameters and mainly, the variation of the tensile strength with the laser cladding strategy is presented. The results show that there is a high directionality of mechanical properties, depending on the strategies of laser cladding process. In other words, the test parts show a fiber -like structure that should be considered on the laser cladding strategy selection.

  4. Influence Of The Laser Cladding Strategies On The Mechanical Properties Of Inconel 718

    NASA Astrophysics Data System (ADS)

    Lamikiz, A.; Tabernero, I.; Ukar, E.; López de Lacalle, L. N.; Delgado, J.

    2011-01-01

    This work presents different experimental results of the mechanical properties of Inconel® 718 test parts built-up by laser cladding. Recently, turbine manufacturers for aeronautical sector have presented high interest on laser cladding processes. This process allows building fully functional structures on superalloys, such as Inconel® 718, with high flexibility on complex shapes. However, there is limited data on mechanical properties of the laser cladding structures. Moreover, the available data do not include the influence of process parameters and laser cladding strategies. Therefore, a complete study of the influence of the laser cladding parameters and mainly, the variation of the tensile strength with the laser cladding strategy is presented. The results show that there is a high directionality of mechanical properties, depending on the strategies of laser cladding process. In other words, the test parts show a fiber -like structure that should be considered on the laser cladding strategy selection.

  5. Fuel/cladding compatibility in irradiated metallic fuel pins at elevated temperatures

    SciTech Connect

    Tsai, Hanchung.

    1990-04-01

    Over fifty fuel/cladding compatibility tests on irradiated metallic fuel specimens have been conducted in an in-cell facility at elevated temperatures. At temperatures below 700--725{degree}C, no fuel/cladding interaction was noted in tests up to 7 h. Liquid-phase cladding penetration occurred in some of the tests at temperatures greater than 725--750{degree}C. The effective rates of liquid- phase cladding penetration of six different fuel/cladding combinations during 1-h testing are reported. After the initial liquefaction at the fuel/cladding interface, which may be affected by the solid-state diffusional interaction during the steady-state irradiation, the rate of further cladding penetration stays constant or decreases with time. There was no runaway cladding penetration in the latter part of a heating cycle.

  6. Applications for reactor-pumped lasers

    NASA Astrophysics Data System (ADS)

    Lipinski, R. J.; McArthur, D. A.

    Nuclear reactor-pumped lasers (RPL's) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

  7. Applications for reactor-pumped lasers

    SciTech Connect

    Lipinski, R.J.; McArthur, D.A.

    1994-10-01

    Nuclear reactor-pumped lasers (RPLs) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

  8. Whole blood pumping with a microthrottle pump

    PubMed Central

    Davies, M. J.; Johnston, I. D.; Tan, C. K. L.; Tracey, M. C.

    2010-01-01

    We have previously reported that microthrottle pumps (MTPs) display the capacity to pump solid phase suspensions such as polystyrene beads which prove challenging to most microfluidic pumps. In this paper we report employing a linear microthrottle pump (LMTP) to pump whole, undiluted, anticoagulated, human venous blood at 200 μl min−1 with minimal erythrocyte lysis and no observed pump blockage. LMTPs are particularly well suited to particle suspension transport by virtue of their relatively unimpeded internal flow-path. Micropumping of whole blood represents a rigorous real-world test of cell suspension transport given blood’s high cell content by volume and erythrocytes’ relative fragility. A modification of the standard Drabkin method and its validation to spectrophotometrically quantify low levels of erythrocyte lysis by hemoglobin release is also reported. Erythrocyte lysis rates resulting from transport via LMTP are determined to be below one cell in 500 at a pumping rate of 102 μl min−1. PMID:21264059

  9. Clad Nd:YAG fibers for laser applications

    SciTech Connect

    Digonnet, M.J.F.; Shaw, H.J.; Gaeta, C.J.; O'meara, D.

    1987-05-01

    The implementation of an extrusion method to clad Nd:YAG single crystal fibers with index-matched glasses (Delta-n = 0.048) is reported. A propagation-loss coefficient of 0.08 dB/cm was measured for the fundamental mode of a 41-micron-diameter glass-clad fiber laser, an improvement of about one order of magnitude over unclad fibers. Guided clad fiber lasers operated at 1.064 microns with thresholds as low as 0.3-0.5 mW and up to 65-mW CW output power are also reported. The origins of and means of reducing the residual loss are discussed. 14 references.

  10. Complete Non-Radioactive Operability Tests for Cladding Hull Chlorination

    SciTech Connect

    Collins, Emory D; Johnson, Jared A.; Hylton, Tom D.; Brunson, Ronald Ray; Hunt, Rodney Dale; DelCul, Guillermo Daniel; Bradley, Eric Craig; Spencer, Barry B.

    2016-04-01

    Non-radioactive operability tests were made to test the metal chlorination reactor and condenser and their accessories using batch chlorinations of non-radioactive cladding samples and to identify optimum operating practices and components that need further modifications prior to installation of the equipment into the hot cell for tests on actual used nuclear fuel (UNF) cladding. The operability tests included (1) modifications to provide the desired heating and reactor temperature profile; and (2) three batch chlorination tests using, respectively, 100, 250, and 500 g of cladding. During the batch chlorinations, metal corrosion of the equipment was assessed, pressurization of the gas inlet was examined and the best method for maintaining solid salt product transfer through the condenser was determined. Also, additional accessing equipment for collection of residual ash and positioning of the unit within the hot cell were identified, designed, and are being fabricated.

  11. Absorptivity Measurements and Heat Source Modeling to Simulate Laser Cladding

    NASA Astrophysics Data System (ADS)

    Wirth, Florian; Eisenbarth, Daniel; Wegener, Konrad

    The laser cladding process gains importance, as it does not only allow the application of surface coatings, but also additive manufacturing of three-dimensional parts. In both cases, process simulation can contribute to process optimization. Heat source modeling is one of the main issues for an accurate model and simulation of the laser cladding process. While the laser beam intensity distribution is readily known, the other two main effects on the process' heat input are non-trivial. Namely the measurement of the absorptivity of the applied materials as well as the powder attenuation. Therefore, calorimetry measurements were carried out. The measurement method and the measurement results for laser cladding of Stellite 6 on structural steel S 235 and for the processing of Inconel 625 are presented both using a CO2 laser as well as a high power diode laser (HPDL). Additionally, a heat source model is deduced.

  12. Nanoscale light–matter interactions in atomic cladding waveguides

    PubMed Central

    Stern, Liron; Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

    2013-01-01

    Alkali vapours, such as rubidium, are being used extensively in several important fields of research such as slow and stored light nonlinear optics quantum computation, atomic clocks and magnetometers. Recently, there is a growing effort towards miniaturizing traditional centimetre-size vapour cells. Owing to the significant reduction in device dimensions, light–matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for nonlinear interactions. Here, taking advantage of the mature platform of silicon photonics, we construct an efficient and flexible platform for tailored light–vapour interactions on a chip. Specifically, we demonstrate light–matter interactions in an atomic cladding waveguide, consisting of a silicon nitride nano-waveguide core with a rubidium vapour cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and show that due to the high confinement of the optical mode, the rubidium absorption saturates at powers in the nanowatt regime. PMID:23462991

  13. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-12-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching {approximately}660{degree}C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  14. Fabrication of stainless steel clad tubing. [gas pressure bonding

    NASA Technical Reports Server (NTRS)

    Kovach, C. W.

    1978-01-01

    The feasibility of producing stainless steel clad carbon steel tubing by a gas pressure bonding process was evaluated. Such a tube product could provide substantial chromium savings over monolithic stainless tubing in the event of a serious chromium shortage. The process consists of the initial assembly of three component tubesets from conventionally produced tubing, the formation of a strong metallurgical bond between the three components by gas pressure bonding, and conventional cold draw and anneal processing to final size. The quality of the tubes produced was excellent from the standpoint of bond strength, mechanical, and forming properties. The only significant quality problem encountered was carburization of the stainless clad by the carbon steel core which can be overcome by further refinement through at least three different approaches. The estimated cost of clad tubing produced by this process is greater than that for monolithic stainless tubing, but not so high as to make the process impractical as a chromium conservation method.

  15. In situ synthesis of hydroxyapatite coating by laser cladding.

    PubMed

    Wang, D G; Chen, C Z; Ma, J; Zhang, G

    2008-10-15

    HA bioceramic coatings were synthesized on titanium substrate by laser cladding using cheap calcium carbonate and calcium hydrogen phosphate. The thermodynamic condition for synthesizing HA was calculated by software Matlab 5.0, the microstructure and phase analysis of laser clad HA bioceramic coatings were studied by electron probe microanalyser (EPMA), X-ray diffractometer (XRD) and transmission electron microscopy (TEM). The theoretical results show that the Gibbs free enthalpy for the synthesis of HA phase is satisfied, and the presence of HA phase in the clad coatings was then further verified by XRD and the selected area diffraction patterns. When the laser power is 600W and the scanning speed is 3.5mm/s, the compact HA bioceramic coatings were obtained, which have cellular dendritic structure and consist of the phases of HA, alpha-Ca(2)P(2)O(7), CaO and CaTiO(3).

  16. Nanoscale light-matter interactions in atomic cladding waveguides.

    PubMed

    Stern, Liron; Desiatov, Boris; Goykhman, Ilya; Levy, Uriel

    2013-01-01

    Alkali vapours, such as rubidium, are being used extensively in several important fields of research such as slow and stored light nonlinear optics quantum computation, atomic clocks and magnetometers. Recently, there is a growing effort towards miniaturizing traditional centimetre-size vapour cells. Owing to the significant reduction in device dimensions, light-matter interactions are greatly enhanced, enabling new functionalities due to the low power threshold needed for nonlinear interactions. Here, taking advantage of the mature platform of silicon photonics, we construct an efficient and flexible platform for tailored light-vapour interactions on a chip. Specifically, we demonstrate light-matter interactions in an atomic cladding waveguide, consisting of a silicon nitride nano-waveguide core with a rubidium vapour cladding. We observe the efficient interaction of the electromagnetic guided mode with the rubidium cladding and show that due to the high confinement of the optical mode, the rubidium absorption saturates at powers in the nanowatt regime.

  17. Performance of HT9 clad metallic fuel at high temperature

    SciTech Connect

    Pahl, R.G.; Lahm, C.E.; Hayes, S.L.

    1992-01-01

    Steady-state testing of HT9 clad metallic fuel at high temperatures was initiated in EBR-II in November of 1987. At that time U-10 wt. % Zr fuel clad with the low-swelling ferritic/martensitic alloy HT9 was being considered as driver fuel options for both EBR-II and FFTF. The objective of the X447 test described here was to determine the lifetime of HT9 cladding when operated with metallic fuel at beginning of life inside wall temperatures approaching [approximately]660[degree]C. Though stress-temperature design limits for HT9 preclude its use for high burnup applications under these conditions due to excessive thermal creep, the X447 test was carried out to obtain data on high temperature breach phenomena involving metallic fuel since little data existed in that area.

  18. High-power in-band pumped Er:YAG laser at 1617 nm.

    PubMed

    Kim, J W; Shen, D Y; Sahu, J K; Clarkson, W A

    2008-04-14

    High-power room-temperature operation of an Er:YAG laser at 1617 nm in-band pumped by a cladding-pumped Er,Yb fiber laser at 1532 nm is reported. The Er:YAG laser yielded 31 W of continuous-wave output in a beam with M(2) approximately = 2.2 for 72 W of incident pump power. The threshold pump power was 4.1 W and the slope efficiency with respect to incident pump power was approximately 47%. The influence of erbium doping level and resonator design on laser performance is discussed, and the prospects for further increase in output power and improvement in lasing efficiency are considered.

  19. High-order harmonic noise-like pulsing of a passively mode-locked double-clad Er/Yb fibre ring laser

    NASA Astrophysics Data System (ADS)

    Pottiez, O.; Hernández-García, J. C.; Ibarra-Escamilla, B.; Kuzin, E. A.; Durán-Sánchez, M.; González-García, A.

    2014-11-01

    In this paper, we study noise-like pulse generation in a km-long fibre ring laser including a double-clad erbium-ytterbium fibre and passively mode-locked through nonlinear polarization evolution. Although single noise-like pulsing is only observed at moderate pump power, pulse energies as high as 120 nJ are reached in this regime. For higher pump power, the pulse splits into several noise-like pulses, which then rearrange into a stable and periodic pulse train. Harmonic mode locking from the 2nd to the 48th orders is readily obtained. At pump powers close to the damage threshold of the setup, much denser noise-like pulse trains are demonstrated, reaching harmonic orders beyond 1200 and repetition frequencies in excess of a quarter of a GHz. The mechanisms leading to noise-like pulse breaking and stable high-order harmonic mode locking are discussed.

  20. 46 CFR 111.60-23 - Metal-clad (Type MC) cable.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Metal-clad (Type MC) cable. 111.60-23 Section 111.60-23...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-23 Metal-clad (Type MC) cable. (a) Metal-clad (Type MC) cable permitted on board a vessel must be continuous corrugated metal-clad cable. (b) The...

  1. Process for Making Optical Fibers from Core and Cladding Glass Rods.

    DTIC Science & Technology

    1996-08-12

    77,577 PATENT APPLICATION Inventor’s Name: Sanghera et al. ORIGINAL 2 3 PROCESS FOR MAKING OPTICAL FIBERS FROM CORE AND CLADDING GLASS 4 RODS S...core and cladding glass rods and to the fibers 10 made by the process. More particularly, the invention relates to 11 separately melting core and...cladding glass rods and combining the 12 melts proximate a fiber drawing orifice so that the core glass is 13 surrounded by the cladding glass and

  2. Report on Reactor Physics Assessment of Candidate Accident Tolerant Fuel Cladding Materials in LWRs

    SciTech Connect

    Powers, Jeffrey J.; George, Nathan; Maldonado, G. Ivan; Worrall, Andrew

    2015-08-28

    This work focuses on ATF concepts being researched at Oak Ridge National Laboratory (ORNL), expanding on previous studies of using alternate cladding materials in pressurized water reactors (PWRs). The neutronic performance of two leading alternate cladding materials were assessed in boiling water reactors (BWRs): iron-chromium-aluminum (FeCrAl) cladding, and silicon carbide (SiC)-based composite cladding. This report fulfills ORNL Milestone M3FT-15OR0202332 within the fiscal year 2015 (FY15)

  3. 46 CFR 111.60-23 - Metal-clad (Type MC) cable.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Metal-clad (Type MC) cable. 111.60-23 Section 111.60-23...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-23 Metal-clad (Type MC) cable. (a) Metal-clad (Type MC) cable permitted on board a vessel must be continuous corrugated metal-clad cable. (b)...

  4. 46 CFR 111.60-23 - Metal-clad (Type MC) cable.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Metal-clad (Type MC) cable. 111.60-23 Section 111.60-23...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-23 Metal-clad (Type MC) cable. (a) Metal-clad (Type MC) cable permitted on board a vessel must be continuous corrugated metal-clad cable. (b)...

  5. 46 CFR 111.60-23 - Metal-clad (Type MC) cable.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Metal-clad (Type MC) cable. 111.60-23 Section 111.60-23...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-23 Metal-clad (Type MC) cable. (a) Metal-clad (Type MC) cable permitted on board a vessel must be continuous corrugated metal-clad cable. (b)...

  6. 46 CFR 111.60-23 - Metal-clad (Type MC) cable.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Metal-clad (Type MC) cable. 111.60-23 Section 111.60-23...-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-23 Metal-clad (Type MC) cable. (a) Metal-clad (Type MC) cable permitted on board a vessel must be continuous corrugated metal-clad cable. (b)...

  7. Evaluation of stainless steel cladding for use in current design LWRs. Final report

    SciTech Connect

    Strasser, A.; Santucci, J.; Lindquist, K.; Yario, W.; Stern, G.; Goldstein, L.; Joseph, L.

    1982-12-01

    The design of stainless steel-clad LWR fuel and its performance at steady-state, transient, and accident conditions were reviewed. The objective was to evaluate the potential benefits and disadvantages of substituting stainless steel-clad fuel for the currently used Zircaloy-clad fuel. For a large, modern PWR, the technology and the fuel-cycle costs of stainless steel- and Zircaloy-clad fuels were compared.

  8. Evaluation of transient fuel pin cladding failure criteria for application to inherently safe LMFBR designs

    SciTech Connect

    Kramer, J M; DiMelfi, R J

    1984-03-01

    Purpose of report is to evaluate the methods for determining time-temperature-stress limits for cladding failure under accident conditions for inherently safe LMFBR designs. The range of expected thermal-mechanical cladding loading conditions is outlined for generic accident events, and application of existing mechanistic and empirical cladding failure models to these conditions is evaluated. The study is restricted to reference oxide fuel pins with austenitic stainless steel cladding.

  9. Multiple pump housing

    DOEpatents

    Donoho, II, Michael R.; Elliott, Christopher M.

    2010-03-23

    A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

  10. Types of Breast Pumps

    MedlinePlus

    ... Powered and Electric Pumps A powered breast pump uses batteries or a cord plugged into an electrical outlet ... pumps rely on a power source, women who use powered breast pumps should be prepared for emergency situations when electricity or extra batteries may not be available. If breastfeeding is not ...

  11. Results of NDE Technique Evaluation of Clad Hydrides

    SciTech Connect

    Kunerth, Dennis C.

    2014-09-01

    This report fulfills the M4 milestone, M4FT-14IN0805023, Results of NDE Technique Evaluation of Clad Hydrides, under Work Package Number FT-14IN080502. During service, zirconium alloy fuel cladding will degrade via corrosion/oxidation. Hydrogen, a byproduct of the oxidation process, will be absorbed into the cladding and eventually form hydrides due to low hydrogen solubility limits. The hydride phase is detrimental to the mechanical properties of the cladding and therefore it is important to be able to detect and characterize the presence of this constituent within the cladding. Presently, hydrides are evaluated using destructive examination. If nondestructive evaluation techniques can be used to detect and characterize the hydrides, the potential exists to significantly increase test sample coverage while reducing evaluation time and cost. To demonstrate the viability this approach, an initial evaluation of eddy current and ultrasonic techniques were performed to demonstrate the basic ability to these techniques to detect hydrides or their effects on the microstructure. Conventional continuous wave eddy current techniques were applied to zirconium based cladding test samples thermally processed with hydrogen gas to promote the absorption of hydrogen and subsequent formation of hydrides. The results of the evaluation demonstrate that eddy current inspection approaches have the potential to detect both the physical damage induced by hydrides, e.g. blisters and cracking, as well as the combined effects of absorbed hydrogen and hydride precipitates on the electrical properties of the zirconium alloy. Similarly, measurements of ultrasonic wave velocities indicate changes in the elastic properties resulting from the combined effects of absorbed hydrogen and hydride precipitates as well as changes in geometry in regions of severe degradation. However, for both approaches, the signal responses intended to make the desired measurement incorporate a number of contributing

  12. Spatial mode-selective waveguide with hyperbolic cladding

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Xi, Z.; Xu, M.; Bäumer, S.; Adam, A. J. L.; Urbach, H. P.

    2016-09-01

    Hyperbolic Meta-Materials~(HMMs) are anisotropic materials with permittivity tensor that has both positive and negative eigenvalues. Here we report that by using a type II HMM as cladding material, a waveguide which only supports higher order modes can be achieved, while the lower order modes become leaky and are absorbed in the HMM cladding. This counter intuitive property can lead to novel application in optical communication and photonic integrated circuit. The loss in our HMM-Insulator-HMM~(HIH) waveguide is smaller than that of similar guided mode in a Metal-Insulator-Metal~(MIM) waveguide.

  13. Characterization of Hydrogen Content in ZIRCALOY-4 Nuclear Fuel Cladding

    NASA Astrophysics Data System (ADS)

    Pfeif, E. A.; Lasseigne, A. N.; Krzywosz, K.; Mader, E. V.; Mishra, B.; Olson, D. L.

    2010-02-01

    Assessment of hydrogen uptake of underwater nuclear fuel clad and component materials will enable improved monitoring of fuel health. Zirconium alloys are used in nuclear reactors as fuel cladding, fuel channels, guide tubes and spacer grids, and are available for inspection in spent fuel pools. With increasing reactor exposure zirconium alloys experience hydrogen ingress due to neutron interactions and water-side corrosion that is not easily quantified without destructive hot cell examination. Contact and non-contact nondestructive techniques, using Seebeck coefficient measurements and low frequency impedance spectroscopy, to assess the hydrogen content and hydride formation within zircaloy 4 material that are submerged to simulate spent fuel pools are presented.

  14. Method and system for edge cladding of laser gain media

    DOEpatents

    Bayramian, Andrew James; Caird, John Allyn; Schaffers, Kathleen Irene

    2014-03-25

    A gain medium operable to amplify light at a gain wavelength and having reduced transverse ASE includes an input surface and an output surface opposing the input surface. The gain medium also includes a central region including gain material and extending between the input surface and the output surface along a longitudinal optical axis of the gain medium. The gain medium further includes an edge cladding region surrounding the central region and extending between the input surface and the output surface along the longitudinal optical axis of the gain medium. The edge cladding region includes the gain material and a dopant operable to absorb light at the gain wavelength.

  15. Welding fixture for nuclear fuel pin cladding assemblies

    DOEpatents

    Oakley, David J.; Feld, Sam H.

    1986-01-01

    A welding fixture for locating a driver sleeve about the open end of a nuclear fuel pin cladding. The welding fixture includes a holder provided with an open cavity having shoulders for properly positioning the driver sleeve, the end cap, and a soft, high temperature resistant plastic protective sleeve that surrounds a portion of the end cap stem. Ejected contaminant particles spewed forth by closure of the cladding by pulsed magnetic welding techniques are captured within a contamination trap formed in the holder for ultimate removal and disposal of contaminating particles along with the holder.

  16. Welding fixture for nuclear fuel pin cladding assemblies

    DOEpatents

    Oakley, D.J.; Feld, S.H.

    1984-02-22

    A welding fixture is described for locating a driver sleeve about the open end of a nuclear fuel pin cladding. The welding fixture includes a holder provided with an open cavity having shoulders for properly positioning the driver sleeve, the end cap, and a soft, high temperature resistant plastic protective sleeve that surrounds a portion of the end cap stem. Ejected contaminant particles spewed forth by closure of the cladding by pulsed magnetic welding techniques are captured within a contamination trap formed in the holder for ultimate removal and disposal of contaminating particles along with the holder.

  17. 77 FR 5052 - Clad Steel Plate From Japan; Institution of a Five-Year Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ... COMMISSION Clad Steel Plate From Japan; Institution of a Five-Year Review AGENCY: United States International... whether revocation of the antidumping duty order on clad steel plate from Japan would be likely to lead to..., the Department of Commerce issued an antidumping duty order on imports of clad steel plate from Japan...

  18. Combination of fuel-cladding chemical and mechanical interactions in mixed oxide fuel pins

    SciTech Connect

    Gotzmann, O.

    1982-04-01

    Encapsulated mixed oxide fuel pins were irradiated in the Belgian reactor BR-2 under epithermal flux conditions. Of 12 pins, 5 failed. Heavy cladding corrosion and significant cladding deformation was observed in postirradiation examination. The failures are attributed to a combined action of fuel-cladding mechanical and chemical interactions, for which favorable conditions existed in these tests.

  19. PIV Measurements in Pumps

    DTIC Science & Technology

    2006-11-01

    Pump Impeller Fig. 37 shows the top view of pump test rig for radial impeller pumps . The goal of this experiment is cavitation observation and their...PIV Measurements in Pumps 5 - 28 RTO-EN-AVT-143 Figure 37: Test Rig for Combined PIV Measurements and Cavitation Observation. Figure 38...RTO-EN-AVT-143 5 - 1 PIV Measurements in Pumps Dr. Detlev L. Wulff TU Braunschweig Institut für Strömungsmaschinen Langer Kamp 6 D-38106

  20. Core-pumped gain-guided index-antiguided continuous wave lasing in dispersion-engineered erbium-doped fiber.

    PubMed

    Chen, Nan-Kuang; Jian, Lian-Jiun

    2012-08-01

    We demonstrate core-pumped gain-guided index-antiguided fiber lasers using a 22 cm long dispersion-engineered erbium-doped fiber. The erbium-doped fiber is dispersion-engineered using optical liquid to replace the most part of silica cladding so that the index of core turns out to be higher (lower) than that of new cladding at pump (lasing) wavelength, respectively. The pump light is confined to propagate in core based on an index-guiding mechanism to efficiently excite the gain medium running through the fiber whereas the cw lasing is constructed in a long, small-core waveguide under a gain-guided, index-antiguided situation.

  1. 10J water-cooled DPSSL system based on Yb:YAG crystal edge-cladded by Cr:YAG ceramics (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zheng, Jian-Gang; Yan, Xiongwei; Jiang, Xinying; Wang, Zhenguo; Li, Mingzhong; Zhang, Jun; Zhu, Qihua; Zheng, Wanguo

    2017-05-01

    equilibrium between the edge cladding and the gain region. the amplifiers can be stably operated under 10Hz. Finally the output of the laser system was about 7.15J@10Hz and 10.8J@1-2Hz. The total optical-to-optical efficiency was about 8.3% for 1-2Hz (under the condition of 120kW/1ms pumping, 880mJ input and 10.8J output) and 5.6% for 10Hz.

  2. DECONTAMINATION OF ZIRCALOY CLADDING HULLS FROM SPENT NUCLEAR FUEL

    SciTech Connect

    Rudisill, T.

    2010-09-29

    The feasibility of decontaminating spent fuel cladding hulls using hydrofluoric acid (HF) was investigated as part of the Global Energy Nuclear Partnership (GNEP) Separations Campaign. The concentrations of the fission product and transuranic (TRU) isotopes in the decontaminated hulls were compared to the limits for determining the low level waste (LLW) classification in the United States (US). The {sup 90}Sr and {sup 137}Cs concentrations met the disposal criteria for a Class C LLW; although, in a number of experiments the criteria for disposal as a Class B LLW were met. The TRU concentration in the hulls generally exceeded the Class C LLW limit by at least an order of magnitude. The concentration decreased sharply as the initial 30-40 {micro}m of the cladding hull surface were removed. At depths beyond this point, the TRU activity remained relatively constant, well above the Class C limit. Reprocessing of spent nuclear fuel generates a cladding waste which would likely require disposal as a Greater than Class C LLW in the US. If the cladding hulls could be treated to remove a majority of the actinide and fission product contamination, the hulls could potentially meet acceptance criteria for disposal as a LLW or allow recycle of the Zr metal. Discard of the hulls as a LLW would result in significant cost savings compared to disposal as a Greater than Class C waste which currently has no disposition path. During fuel irradiation and reprocessing, radioactive materials are produced and deposited in the Zircaloy cladding. Due to short depths of penetration, the majority of the fission products and actinide elements are located in the ZrO{sub 2} layer which forms on the surface of the cladding during fuel irradiation. Therefore, if the oxide layer is removed, the majority of the contamination should also be removed. It is very difficult, if not impossible to remove all of the activity from spent fuel cladding since traces of U and Th in the unirradiated Zircaloy

  3. Continuously pumping and reactivating gas pump

    DOEpatents

    Batzer, T.H.; Call, W.R.

    Apparatus for continuous pumping using cycling cryopumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels that alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independant pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

  4. Continuously pumping and reactivating gas pump

    DOEpatents

    Batzer, Thomas H.; Call, Wayne R.

    1984-01-01

    Apparatus for continuous pumping using cycling cyropumping panels. A plurality of liquid helium cooled panels are surrounded by movable nitrogen cooled panels the alternatively expose or shield the helium cooled panels from the space being pumped. Gases condense on exposed helium cooled panels until the nitrogen cooled panels are positioned to isolate the helium cooled panels. The helium cooled panels are incrementally warmed, causing captured gases to accumulate at the base of the panels, where an independent pump removes the gases. After the helium cooled panels are substantially cleaned of condensate, the nitrogen cooled panels are positioned to expose the helium cooled panels to the space being pumped.

  5. Alternative backing up pump for turbomolecular pumps

    DOEpatents

    Myneni, Ganapati Rao

    2003-04-22

    As an alternative to the use of a mechanical backing pump in the application of wide range turbomolecular pumps in ultra-high and extra high vacuum applications, palladium oxide is used to convert hydrogen present in the evacuation stream and related volumes to water with the water then being cryo-pumped to a low pressure of below about 1.e.sup.-3 Torr at 150.degree. K. Cryo-pumping is achieved using a low cost Kleemenco cycle cryocooler, a somewhat more expensive thermoelectric cooler, a Venturi cooler or a similar device to achieve the required minimization of hydrogen partial pressure.

  6. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating.

    PubMed

    Yang, Tingting; Qiao, Xueguang; Rong, Qiangzhou; Bao, Weijia

    2016-09-11

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending dependence, together with a strong orientation dependence because of asymmetrical distribution of the "cladding" FBG along the fiber cross-section.

  7. Direct Laser Cladding , Current Status and Future Scope of Application

    NASA Astrophysics Data System (ADS)

    Weisheit, A.; Gasser, A.; Backes, G.; Jambor, T.; Pirch, N.; Wissenbach, K.

    During the last decades Direct Laser Cladding has become an established technique in many industrial fields for applying wear and corrosion protection layers on metallic surfaces as well as for the repair of high value-added components. The most important application fields are die and tool making, turbine components for aero engines and power generation, machine components such as axes and gears, and oil drilling components. Continuous wave (CW) lasers with a power up to 18 kW are used on automated machines with three or more axes, enabling 3D cladding . The outstanding feature of DLC is the high precision which leads to a minimum heat input into the work piece and a very low distortion. Due to the high cooling rates a fine grained microstructure is achieved during solidification. A new development in laser cladding is micro cladding in a size range below 50 \\upmum especially for electronic and medical applications. Furthermore, additive manufacturing is coming again into focus as a clean and resource-efficient method to manufacture and modify functional prototypes as well as unique and small lot parts.

  8. Iridium alloy Clad Vent Set manufacturing qualification studies

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.

    Metallurgical qualification studies to demonstrate the manufacturing readiness of the iridium alloy Clad Vent Set (CVS) for the General Purpose Heat Source program at the Oak Ridge Y-12 Plant are described. Microstructural data for various materials/test conditions are presented.

  9. Underwater cladding with laser beam and plasma arc welding

    SciTech Connect

    White, R.A.; Fusaro, R.; Jones, M.G.; Solomon, H.D.; Milian-Rodriguez, R.R.

    1997-01-01

    Two welding processes, plasma arc (transferred arc) (PTA) and laser beam, were investigated to apply cladding to austenitic stainless steels and Inconel 600. These processes have long been used to apply cladding layers , but the novel feature being reported here is that these cladding layers were applied underwater, with a water pressure equivalent to 24 m (80 ft). Being able to apply the cladding underwater is very important for many applications, including the construction of off-shore oil platforms and the repair of nuclear reactors. In the latter case, being able to weld underwater eliminates the need for draining the reactor and removing the fuel. Welding underwater in reactors presents numerous challenges, but the ability to weld without having to drain the reactor and remove the fuel provides a huge cost savings. Welding underwater in reactors must be done remotely, but because of the radioactive corrosion products and neutron activation of the steels, remote welding would also be required even if the reactor is drained and the fuel removed. In fact, without the shielding of the water, the remote welding required if the reactor is drained might be even more difficult than that required with underwater welds. Furthermore, as shall be shown, the underwater welds that the authors have made were of high quality and exhibit compressive rather than tensile residual stresses.

  10. Optimization of Hydride Rim Formation in Unirradiated Zr 4 Cladding

    SciTech Connect

    Shimskey, Rick W.; Hanson, Brady D.; MacFarlan, Paul J.

    2013-09-30

    The purpose of this work is to build on the results reported in the M2 milestone M2FT 13PN0805051, document number FCRD-USED-2013-000151 (Hanson, 2013). In that work, it was demonstrated that unirradiated samples of zircaloy-4 cladding could be pre-hydrided at temperatures below 400°C in pure hydrogen gas and that the growth of hydrides on the surface could be controlled by changing the surface condition of the samples and form a desired hydride rim on the outside diameter of the cladding. The work performed at Pacific Northwest National Laboratory since the issuing of the M2 milestone has focused its efforts to optimize the formation of a hydride rim on available zircaloy-4 cladding samples by controlling temperature variation and gas flow control during pre-hydriding treatments. Surface conditioning of the outside surface was also examined as a variable. The results of test indicate that much of the variability in the hydride thickness is due to temperature variation occurring in the furnaces as well as how hydrogen gas flows across the sample surface. Efforts to examine other alloys, gas concentrations, and different surface conditioning plan to be pursed in the next FY as more cladding samples become available

  11. The Prediction of Laser Clad Parameters Based on Neural Network

    NASA Astrophysics Data System (ADS)

    Liu, Jichang; Ni, Libin

    2011-06-01

    Because laser cladding is a multi-variable coupling process, the relation between clad bead and process parameters is non-linear with multi-objects and multi-variables. Moreover, it is very difficult to find out an exact analytic model to express this relation. In this study, a neural network model, which is often used for non-linear problems, is developed to explain the relationship between process variables and clad parameters (the width and height of cladding bead). Some samples obtained in experiments are used to train the network model to form the perfect map relation between input and output, and other samples are employed to test the network model. A normal BP algorithm and an amend BP one are trained, and it is found that the amend BP algorithm has advantages over the normal BP one. The experimental results agreed well with those calculated with the neural network model, which indicates that the developed BP neural network prediction model is feasible and valid in theory and in practice.

  12. Cladding burst behavior of Fe-based alloys under LOCA

    DOE PAGES

    Terrani, Kurt A.; Dryepondt, Sebastien N.; Pint, Bruce A.; ...

    2015-12-17

    Burst behavior of austenitic and ferritic Fe-based alloy tubes has been examined under a simulated large break loss of coolant accident. Specifically, type 304 stainless steel (304SS) and oxidation resistant FeCrAl tubes were studied alongside Zircaloy-2 and Zircaloy-4 that are considered reference fuel cladding materials. Following the burst test, characterization of the cladding materials was carried out to gain insights regarding the integral burst behavior. Given the widespread availability of a comprehensive set of thermo-mechanical data at elevated temperatures for 304SS, a modeling framework was implemented to simulate the various processes that affect burst behavior in this Fe-based alloy. Themore » most important conclusion is that cladding ballooning due to creep is negligible for Fe-based alloys. Thus, unlike Zr-based alloys, cladding cross-sectional area remains largely unchanged up to the point of burst. Furthermore, for a given rod internal pressure, the temperature onset of burst in Fe-based alloys appears to be simply a function of the alloy's ultimate tensile strength, particularly at high rod internal pressures.« less

  13. Cladding burst behavior of Fe-based alloys under LOCA

    SciTech Connect

    Terrani, Kurt A.; Dryepondt, Sebastien N.; Pint, Bruce A.; Massey, Caleb P.

    2015-12-17

    Burst behavior of austenitic and ferritic Fe-based alloy tubes has been examined under a simulated large break loss of coolant accident. Specifically, type 304 stainless steel (304SS) and oxidation resistant FeCrAl tubes were studied alongside Zircaloy-2 and Zircaloy-4 that are considered reference fuel cladding materials. Following the burst test, characterization of the cladding materials was carried out to gain insights regarding the integral burst behavior. Given the widespread availability of a comprehensive set of thermo-mechanical data at elevated temperatures for 304SS, a modeling framework was implemented to simulate the various processes that affect burst behavior in this Fe-based alloy. The most important conclusion is that cladding ballooning due to creep is negligible for Fe-based alloys. Thus, unlike Zr-based alloys, cladding cross-sectional area remains largely unchanged up to the point of burst. Furthermore, for a given rod internal pressure, the temperature onset of burst in Fe-based alloys appears to be simply a function of the alloy's ultimate tensile strength, particularly at high rod internal pressures.

  14. A Multi-Scale Modeling of Laser Cladding Process (Preprint)

    DTIC Science & Technology

    2006-04-01

    possibilities to alter a component at its surface. Despite immense potentials and advancements, the process model of microstructure evolution and its coupling...with macro parameter of laser cladding process has not been fully developed. To address this issue, a process model of microstructure evolution has

  15. Improved Synthesis of Carbon Clad Silica Stationary Phases

    PubMed Central

    Ahmad, Imad A. Haidar; Carr, Peter W.

    2014-01-01

    Previously we described a novel method for clading elemental carbon onto the surface of catalytically activated silica by a chemical vapor deposition (CVD) method using hexane as the carbon source and its use as a substitute for carbon clad zirconia.1,2 In that method, we showed that very close to exactly one uniform monolayer of Al (III) was deposited on the silica by a process analogous to precipitation from homogeneous solution in order to preclude pore blockage. The purpose of the Al(III) monolayer layer is to activate the surface for subsequent CVD of carbon. In this work, we present an improved procedure for preparing the carbon clad silica (denoted CCSi) phases along with a new column packing process. The new method yields CCSi phases having better efficiency, peak symmetry and higher retentivity compared to carbon clad zirconia. The enhancements were achieved by modifying the original procedure in three ways: first. the kinetics of the deposition of Al(III) were more stringently controlled, second the CVD chamber was flushed with a mixture of hydrogen and nitrogen gas during the carbon cladding process to minimize generation of polar sites by oxygen incorporation, and third the fine particles generated during the CVD process were exhaustively removed by flotation in an appropriate solvent. PMID:24228897

  16. Multispectral pyrometry for surface temperature measurement of oxidized Zircaloy claddings

    NASA Astrophysics Data System (ADS)

    Bouvry, B.; Cheymol, G.; Ramiandrisoa, L.; Javaudin, B.; Gallou, C.; Maskrot, H.; Horny, N.; Duvaut, T.; Destouches, C.; Ferry, L.; Gonnier, C.

    2017-06-01

    Non-contact temperature measurement in a nuclear reactor is still a huge challenge because of the numerous constraints to consider, such as the high temperature, the steam atmosphere, and irradiation. A device is currently developed at CEA to study the nuclear fuel claddings behavior during a Loss-of-Coolant Accident. As a first step of development, we designed and tested an optical pyrometry procedure to measure the surface temperature of nuclear fuel claddings without any contact, under air, in the temperature range 700-850 °C. The temperature of Zircaloy-4 cladding samples was retrieved at various temperature levels. We used Multispectral Radiation Thermometry with the hypothesis of a constant emissivity profile in the spectral ranges 1-1.3 μm and 1.45-1.6 μm. To allow for comparisons, a reference temperature was provided by a thermocouple welded on the cladding surface. Because of thermal losses induced by the presence of the thermocouple, a heat transfer simulation was also performed to estimate the bias. We found a good agreement between the pyrometry measurement and the temperature reference, validating the constant emissivity profile hypothesis used in the MRT estimation. The expanded measurement uncertainty (k = 2) of the temperature obtained by the pyrometry method was ±4 °C, for temperatures between 700 and 850 °C. Emissivity values, between 0.86 and 0.91 were obtained.

  17. Fundamental metallurgical aspects of axial splitting in zircaloy cladding

    SciTech Connect

    Chung, H. M.

    2000-04-03

    Fundamental metallurgical aspects of axial splitting in irradiated Zircaloy cladding have been investigated by microstructural characterization and analytical modeling, with emphasis on application of the results to understand high-burnup fuel failure under RIA situations. Optical microscopy, SEM, and TEM were conducted on BWR and PWR fuel cladding tubes that were irradiated to fluence levels of 3.3 x 10{sup 21} n cm{sup {minus}2} to 5.9 x 10{sup 21} n cm{sup {minus}2} (E > 1 MeV) and tested in hot cell at 292--325 C in Ar. The morphology, distribution, and habit planes of macroscopic and microscopic hydrides in as-irradiated and posttest cladding were determined by stereo-TEM. The type and magnitude of the residual stress produced in association with oxide-layer growth and dense hydride precipitation, and several synergistic factors that strongly influence axial-splitting behavior were analyzed. The results of the microstructural characterization and stress analyses were then correlated with axial-splitting behavior of high-burnup PWR cladding reported for simulated-RIA conditions. The effects of key test procedures and their implications for the interpretation of RIA test results are discussed.

  18. Performance of titanium stabilized D9 cladding and ducts

    SciTech Connect

    Makenas, B J

    1986-04-01

    A series of mixed oxide UO/sub 2/-PuO/sub 2/ Liquid Metal Reactor (LMR) Fuel assemblies using D9 alloy cladding and/or ducts have been irradiated to high exposure in the Fast Flux Test Facility (FFTF) with very encouraging results. D9 is a titanium modified variant of 316 stainless steel. The highest burnup attained for 316 stainless steel clad driver fuel pins in FFTF has been achieved in an assembly with a cold worked D9 duct while assemblies which simultaneously utilize both D9 ducts and D9 clad pins have achieved burnups as high as 155 MWd/kgM with a corresponding fast fluence of 25 x 10/sup 22/ n/cm/sup 2/. The cold worked D9 ducts demonstrated less length increase and less dilation than their Cold Worked 316 SS counterparts. The D9 pins also showed less length and diameter increase than comparable 316 SS pins with less evidence of deformation due to interference between the pin bundle and the duct. Corrosion behavior at the inner and outer surface of the D9 cladding has proved to be very similar to that of 316 stainless steel.

  19. Comments on ""Contact Diffusion Interaction of Materials with Cladding''

    NASA Technical Reports Server (NTRS)

    Morris, J. F.

    1972-01-01

    A Russian paper by A. A. Babad-Zakhryapina contributes much to the understanding of fuel, clad interactions, and thus to nuclear thermionic technology. In that publication the basic diffusion expression is a simple one. A more general but complicated equation for this mass transport results from the present work. With appropriate assumptions, however, the new relation reduces to Babad-Zakhryapina's version.

  20. An Innovative Ceramic Corrosion Protection System for Zircaloy Cladding

    SciTech Connect

    Ronald H. Baney, Dr. D. Butt, Dr. P. Demkowicz, Dr. G. Fuchs Department of Materials Science; James S. Tulenko, Department of Nuclear and Radiological Engineering; University of Florida.

    2003-02-19

    Light Water reactor (LWR) fuel performance is currently limited by thermal, chemical and mechanical constraints associated with the design, fabrication, and operation of the fuel in incore operation. Corrosion of the zirconium based (Zircaloy-4) alloy cladding of the fuel is a primary limiting factor. Recent success at the University of Florida in developing thin ceramic films with great adhesive properties for metal substrates offers an innovative breakthrough for eliminating a major weakness of the Zircaloy clad. ?The University of Florida proposes to coat the existing Zircaloy clad tubes with a ceramic coating for corrosion protection. An added bonus of this approach would be the implementation of a boron-containing burnable poison outer layer will also be demonstrated as part of the ceramic coating development. In this proposed effort, emphasis will be on the ceramic coating with only demonstration of feasibility on the burnable outer coating approach. This proposed program i s expected to give a step change (approximately a doubling) in clad lifetime before failure due to corrosion. In the development of ceramic coatings for Zircaloy-4 clad, silicon carbide and zirconium carbide coatings will first be applied to Zircaloy-4 coupons and cladding samples by thermal assisted chemical vapor deposition, plasma assisted chemical vapor deposition or by laser ablation deposition. All of these processes are in use at the University of Florida and have shown great potential. The questions of adhesion and thermal expansion mismatch of the ceramic coating to the Zircaloy substrate will be addressed. Several solutions to these conditions will be examined, if needed. These solutions include the use of a zirconium oxide compliant layer, employment of a laser roughened surface and the use of a gradient composition interlayer. These solutions have already been shown to be effective for other high modulus coatings on metal substrates. Mechanical properties and adhesion of the

  1. Fuel/cladding compatibility in high-burnup U-19 Pu-10 Zr/HT-9 clad fuel at elevated temperatures

    SciTech Connect

    Cohen, A.B.; Tsai, H.; Sanecki, J.E.; Neimark, L.A. )

    1992-01-01

    The U-Pu-Zr metallic fuel in the integral fast reactor may interact chemically with the steel cladding at elevated temperatures, leading to a thinning of the cladding and eventual pin failure. Also, as a result of the fuel/cladding chemical interaction (FCCI), iron may diffuse into the fuel and form a lower melting phase with uranium and plutonium. If the temperature is raised above the solidus temperature of this phase, the fuel can undergo liquefaction, i.e., the formation of a mixture of liquid and solid phases, that may promote further cladding interaction. Fuel/cladding chemical interaction, therefore, is a complex phenomenon on both sides of the fuel/cladding interface that depends on fuel and cladding compositions, linear power rating, burnup, and cladding temperature. The purpose of this study was to determine the temperature at which the fuel/cladding interaction region forms solid-plus-liquid phases above the normal in-reactor operating temperatures of high-burnup (11 at.%) Mark V-type fuel for the Experimental Breeder Reactor II (EBR-II). The Mark V fuel is being developed as a future driver fuel for the reactor. The effect of this solid-plus-liquid mixture on the kinetics and mechanism of FCCI was also investigated. This paper updates results previously reported for lower-burnup Mark V-type fuel elements.

  2. Optimal quantum pumps.

    PubMed

    Avron, J E; Elgart, A; Graf, G M; Sadun, L

    2001-12-03

    We study adiabatic quantum pumps on time scales that are short relative to the cycle of the pump. In this regime the pump is characterized by the matrix of energy shift which we introduce as the dual to Wigner's time delay. The energy shift determines the charge transport, the dissipation, the noise, and the entropy production. We prove a general lower bound on dissipation in a quantum channel and define optimal pumps as those that saturate the bound. We give a geometric characterization of optimal pumps and show that they are noiseless and transport integral charge in a cycle. Finally we discuss an example of an optimal pump related to the Hall effect.

  3. A Novel Method of Modeling the Deformation Resistance for Clad Sheet

    SciTech Connect

    Hu Jianliang; Yi Youping; Xie Mantang

    2011-08-22

    Because of the excellent thermal conductivity, the clad sheet (3003/4004/3003) of aluminum alloy is extensively used in various heat exchangers, such as radiator, motorcar air conditioning, evaporator, and so on. The deformation resistance model plays an important role in designing the process parameters of hot continuous rolling. However, the complex behaviors of the plastic deformation of the clad sheet make the modeling very difficult. In this work, a novel method for modeling the deformation resistance of clad sheet was proposed by combining the finite element analysis with experiments. The deformation resistance model of aluminum 3003 and 4004 was proposed through hot compression test on the Gleeble-1500 thermo-simulation machine. And the deformation resistance model of clad sheet was proposed through finite element analysis using DEFORM-2D software. The relationship between cladding ratio and the deformation resistance was discussed in detail. The results of hot compression simulation demonstrate that the cladding ratio has great effects on the resistance of the clad sheet. Taking the cladding ratio into consideration, the mathematical model of the deformation resistance for clad sheet has been proved to have perfect forecasting precision of different cladding ratio. Therefore, the presented model can be used to predict the rolling force of clad sheet during the hot continuous rolling process.

  4. Cladding inner surface wastage for mixed-oxide liquid metal reactor fuel pins

    SciTech Connect

    Lawrence, L.A.; Bard, F.E.; Cannon, N.S.

    1990-11-01

    Cladding inner surface wastage was measured on reference fuel pins with stainless steel and D9 cladding irradiated beyond goal burnup in the Fast Flux Test Facility. Measurements were compared to the Experimental Breeder Reactor No. 2 based fuel-cladding chemical interaction correlation developed for uranium-plutonium oxide fuels with 20% cold-worked stainless steel cladding. The fuel-cladding chemical interaction was also measured in fuel pins irradiated with HT9 cladding. Comparison of the measurements with the design correlation showed the correlation adequately accounted for the extent of interaction in the Fast Flux Test Facility fuel pins with cold-worked stainless steel D9, and HT9 cladding. 9 refs., 6 figs.

  5. Studies of central wavelength of high-power all-fiber superfluorescent sources with Yb-doped double-clad fibers

    NASA Astrophysics Data System (ADS)

    Yan, Ping; Sun, Junyi; Li, Dan; Gong, Mali; Xiao, Qirong

    2016-12-01

    The behavior patterns and dependencies of the central wavelength of high-power all-fiber superfluorescent sources (SFS) were studied based on the steady-state rate equations of Yb-doped fiber lasers. The relationships between the central wavelength and the pumping power as well as the fiber parameters including fiber length, core size, core/clad ratio, and absorption coefficient were analyzed based on the gain coefficient of the gain fiber. Experimental results from ten different fibers are presented, and the results agreed well with the simulations. The central wavelength of the ten SFSs ranged from 1034.75 nm to 1072.4 nm.

  6. High-beam quality, high-efficiency laser based on fiber with heavily Yb(3+)-doped phosphate core and silica cladding.

    PubMed

    Egorova, O N; Semjonov, S L; Medvedkov, O I; Astapovich, M S; Okhrimchuk, A G; Galagan, B I; Denker, B I; Sverchkov, S E; Dianov, E M

    2015-08-15

    We have fabricated and tested a composite fiber with an Yb(3+)-doped phosphate glass core and silica cladding. Oscillation with a slope efficiency of 74% was achieved using core pumping at 976 nm with fiber lengths of 48-90 mm in a simple laser configuration, where the cavity was formed by a high-reflectivity Bragg grating and the cleaved fiber end. The measured M(2) factors were as low as 1.05-1.22 even though the fiber was multimode at the lasing wavelength.

  7. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, M.; Ward, R.L.

    1991-12-24

    This patent describes a fluid sampling pump for withdrawing pressurized sample fluid from a flow line and for pumping a preselected quantity of sample fluid with each pump driving stroke from the pump to a sample vessel, the sampling pump including a pump body defining a pump bore therein having a central axis, a piston slideably moveable within the pump bore and having a fluid inlet end and an opposing operator end, a fluid sample inlet port open to sample fluid in the flow line, a fluid sample outlet port for transmitting fluid from the pump bore to the sample vessel, and a line pressure port in fluid pressure sample fluid in the flow line, an inlet valve for selectively controlling sample fluid flow from the flow line through the fluid sample inlet port, an operator unit for periodically reciprocating the piston within the pump bore, and a controller for regulating the stroke of the piston within the pump bore, and thereby the quantity of fluid pumped with each pump driving stroke. It comprises a balanced check valve seat; a balanced check valve seal; a compression member; and a central plunger.

  8. Gas pump with movable gas pumping panels

    DOEpatents

    Osher, John E.

    1984-01-01

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  9. Gas pump with movable gas pumping panels

    DOEpatents

    Osher, J.L.

    Apparatus for pumping gas continuously a plurality of articulated panels of getter material, each of which absorbs gases on one side while another of its sides is simultaneously reactivated in a zone isolated by the panels themselves from a working space being pumped.

  10. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  11. Insulin pump (image)

    MedlinePlus

    The catheter at the end of the insulin pump is inserted through a needle into the abdominal ... with diabetes. Dosage instructions are entered into the pump's small computer and the appropriate amount of insulin ...

  12. Sizing pumps for slurries

    SciTech Connect

    Akhtar, S.Z.

    1996-11-01

    Slurry characteristics have a significant impact on centrifugal pump performance. For instance, as particle size increases or the percent solids concentration increases, pump head and efficiency decrease. Therefore, before a slurry pump is selected, it is important to define the slurry characteristics as accurately as possible. The effect of the slurry characteristics on the head and efficiency of the centrifugal pump will be emphasized (the effect on flowrate is less significant). The effect of slurry characteristics is more predominant in smaller pumps (with smaller diameter impellers) than in larger pumps. The data and relationship between the various slurry parameters have been developed from correlations and nomographs published by pump vendors from their field data and test results. The information helps to avoid specifying an undersized pump/motor assembly for slurry service.

  13. Liquid metal enabled pump.

    PubMed

    Tang, Shi-Yang; Khoshmanesh, Khashayar; Sivan, Vijay; Petersen, Phred; O'Mullane, Anthony P; Abbott, Derek; Mitchell, Arnan; Kalantar-Zadeh, Kourosh

    2014-03-04

    Small-scale pumps will be the heartbeat of many future micro/nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics.

  14. Liquid metal enabled pump

    PubMed Central

    Tang, Shi-Yang; Khoshmanesh, Khashayar; Sivan, Vijay; Petersen, Phred; O’Mullane, Anthony P.; Abbott, Derek; Mitchell, Arnan; Kalantar-zadeh, Kourosh

    2014-01-01

    Small-scale pumps will be the heartbeat of many future micro/nanoscale platforms. However, the integration of small-scale pumps is presently hampered by limited flow rate with respect to the input power, and their rather complicated fabrication processes. These issues arise as many conventional pumping effects require intricate moving elements. Here, we demonstrate a system that we call the liquid metal enabled pump, for driving a range of liquids without mechanical moving parts, upon the application of modest electric field. This pump incorporates a droplet of liquid metal, which induces liquid flow at high flow rates, yet with exceptionally low power consumption by electrowetting/deelectrowetting at the metal surface. We present theory explaining this pumping mechanism and show that the operation is fundamentally different from other existing pumps. The presented liquid metal enabled pump is both efficient and simple, and thus has the potential to fundamentally advance the field of microfluidics. PMID:24550485

  15. A long uniform taper applied to an all-fiber Tm3+ doped double-clad fiber laser

    NASA Astrophysics Data System (ADS)

    Zhang, Y. J.; Zhong, F. F.; He, W. B.; Zhang, Y.; Wang, Y.; Xu, J.; Ju, Y. L.

    2010-11-01

    A long uniform taper fabricated on a large mode area Tm3+-doped double-clad fiber laser, which was clad-pumped by a laser diode (LD), was found to be an effective wavelength filter while improving the output beam quality and narrowing the line-width significantly. The long uniform taper was fabricated directly on the multi-mode Tm3+-doped fiber by heating and stretching method, and located several centimeters before the output fiber end. By slightly bending the taper section, the output laser spectrum was left with only one peak with a line-width less than 0.5 nm, compared to the multi-peak spectrum with a 5 nm line-width before tapering, indicating that the multi-mode fiber could produce quasi-single wavelength output with a long uniform taper. The beam quality factor M 2 declined from 6.6 to 2.6 compared. Only a slight decrease in slope efficiency, from 19.2 to 17.5%, was observed. The main output wavelength had a blue shift of 8 nm.

  16. Watt-level passively Q-switched double-cladding fiber laser based on graphene oxide saturable absorber.

    PubMed

    Yu, Zhenhua; Song, Yanrong; Dong, Xinzheng; Li, Yanlin; Tian, Jinrong; Wang, Yonggang

    2013-10-10

    A watt-level passively Q-switched ytterbium-doped double-cladding fiber laser with a graphene oxide (GO) absorber was demonstrated. The structure of the GO saturable absorber mirror (GO-SAM) was of the sandwich type. A maximum output power of 1.8 W was obtained around a wavelength of 1044 nm. To the best of our knowledge, this is the highest output power in Q-switched fiber lasers based on a GO saturable absorber. The pure GO was protected from the oxygen in the air so that the damage threshold of the GO-SAM was effectively raised. The gain fiber was a D-shaped ytterbium-doped double-cladding fiber. The pulse repetition rates were tuned from 120 to 215 kHz with pump powers from 3.89 to 7.8 W. The maximum pulse energy was 8.37 μJ at a pulse width of 1.7 μs.

  17. Cladding hull decontamination and densification process. Part 1. The prototype cladding hull decontamination system

    SciTech Connect

    Lambright, T.M.; Montgomery, D.R.

    1980-04-01

    A prototype system for decontaminating Zircaloy-4 cladding hulls has been assembled and tested at Pacific Northwest Laboratory. The decontamination process consists of treatment with a gaseous mixture of hydrogen fluoride (HF) and argon (Ar) followed by a dilute aqueous etch of ammonium oxalate, ammonium citrate, ammonium fluoride, and hydrogen peroxide. The continuous cleaning process described in this report successfully descaled small portions of most charges, but was unable to handle the original design capacity of 4 kg/hr because of problems in the following areas: control of HF reactor temperatures, regulation of HF and argon mixtures and flows, isolation of the HF reactor atmosphere from the aqueous washer/rinser atmosphere, regulation of undesirable side reactions, and control over hull transport through the system. Due to the limited time available to solve these problems, the system did not attain fully operational status. The work was performed with unirradiated hulls that simulated irradiated hulls. The system was not built to be remotely operable. The process chemistry and system equipment are described in this report with particular emphasis on critical operating areas. Recommendations for improved system operation are included.

  18. Investigation of a quadrupole ultra-high vacuum ion pump

    NASA Technical Reports Server (NTRS)

    Schwarz, H. J.

    1974-01-01

    The new nonmagnetic ion pump resembles the quadrupole ionization gage. The dimensions are larger, and hyperbolically shaped electrodes replace the four rods. Their surfaces follow y sq. = 36 + x sq. (x, y in centimeters). The electrodes, 55 cm long, are positioned lengthwise in a tube. At one end a cathode emits electrons; at the other end a narrowly wound flat spiral of tungsten clad with titanium on cathode potential can be heated for titanium evaporation. Electrons accelerated by a dc potential of the surface electrodes oscillate between the ends on rotational trajectories, if a high frequency potential superimposed on the dc potential is properly adjusted. Pumping speeds (4-100 liter/sec) for different gases at different peak voltages (1000-3000V) at corresponding frequencies (57-100 MHz), and at different pressures 0.00001 to the minus 9 power Torr were observed. The lowest pressure reached was below 10 to the minus 10 power Torr.

  19. Photovoltaic pump systems

    NASA Astrophysics Data System (ADS)

    Klockgether, J.; Kiessling, K. P.

    1983-09-01

    Solar pump systems for the irrigation of fields and for water supply in regions with much sunshine are discussed. For surface water and sources with a hoisting depth of 12 m, a system with immersion pumps is used. For deep sources with larger hoisting depths, an underwater motor pump was developed. Both types of pump system meet the requirements of simple installation and manipulation, safe operation, maintenance free, and high efficiency reducing the number of solar cells needed.

  20. Heat pump systems

    SciTech Connect

    Sauer, H.J.; Howell, R.H.

    1983-01-01

    This book was written as a reference and textbook on heat pumps. Economics, thermodynamics, heat transfer, design, selection, and operating practices are covered in detail. Specific methods, and solutions rather than broad generalizations are emphasized. Includes problems, bibliographies, and a subject index. For applied science collections in public, college and appropriate special libraries. Contents: Thermodynamics, Heat pump systems and applications. Heat pump components. Heating and cooling loads. Energy use determination. Reliability, maintenance, and service. Advances in heat pumps. Appendices. Index.

  1. Rotary magnetic heat pump

    DOEpatents

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  2. Centrifuge pump selection

    SciTech Connect

    Buehler, M.W.

    1985-12-01

    Selection of a centrifuge pump is addressed. The problem of assessing pump needs based on system design is broken down into a step-by-step approach. Topics included are designing the pump system, calculating such pressure NPSH, and building in a safety factor.

  3. Centrifugal main fuel pump

    SciTech Connect

    Cole, E.F.

    1986-08-26

    For a gas turbine power plant having a fuel supply and a fuel metering valve and variable geometry for the power plant including servo actuating mechanisms for the fuel metering valve and variable geometry, a fuel pumping system, is described to supply pressurized fuel for the servo actuating mechanisms and for the engine working fluid medium. The pumping system includes a centrifugal pump solely supplying the fuel to the fuel metering valve to be delivered to the power plant for its working fluid medium, a positive displacement pump in parallel with the centrifugal pump and solely to supply pressurized fuel to the servo actuating mechanisms for the fuel metering valve and for the variable geometry, and a boost pump means disposed in serial relationship with the positive displacement pump and the centrifugal pump for augmenting the pressure supplied by the positive displacement pump and the centrifugal pump during predetermined operating conditions of the power plant. The combined boost pump and centrifugal pump capability is sufficient to satisfy the vapor to liquid ratio requirements of the power during its entire operating envelope.

  4. Green pumped Alexandrite lasers

    NASA Astrophysics Data System (ADS)

    Kuper, Jerry W.; Brown, David C.

    2005-04-01

    Initial experiments with pulsed and CW pumping an alexandrite laser rod at 532 nm are presented. This pumping architecture holds promise for the production of scalable diode-pumped, tunable alexandrite laser systems operating in the near infrared (750 nm), and the ultraviolet (375 and 250 nm) spectral regions.

  5. Rotary magnetic heat pump

    DOEpatents

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  6. Efficient wavelength-tunable operation of tandem-pumped Yb fiber lasers

    NASA Astrophysics Data System (ADS)

    Jung, Y. J.; Jeon, M. J.; Jeong, H.; Kim, J. W.

    2017-02-01

    Highly efficient operation of double-clad Yb fiber lasers with fixed-wavelength and wavelength-tunable resonator configurations tandem-pumped by tunable Yb fiber lasers is reported. When wavelength selection was achieved using volume Bragg gratings in an external feedback cavity, the tandem-pumped Yb fiber laser produced maximum output powers of 7.0, 6.8, and 6.4 W at 1070 nm, corresponding to slope efficiencies of 88.2, 87.8, and 89.5%, for pump wavelengths of 1020, 1025, and 1030 nm, respectively. The wavelength-tunable fiber laser employing volume Bragg gratings and diffraction gratings was tuned from 1055 to 1112 nm with a linewidth of 0.3 nm (FWHM), which was in good agreement with the calculated gain spectra. Optimization of tandem-pumped Yb fiber lasers and the prospect for further improvement in performance are considered.

  7. 1-kilowatt CW all-fiber laser oscillator pumped with wavelength-beam-combined diode stacks.

    PubMed

    Xiao, Y; Brunet, F; Kanskar, M; Faucher, M; Wetter, A; Holehouse, N

    2012-01-30

    We have demonstrated a monolithic cladding-pumped ytterbium-doped single all-fiber laser oscillator generating 1 kW of CW signal power at 1080 nm with 71% slope efficiency and near diffraction-limited beam quality. Fiber components were highly integrated on "spliceless" passive fibers to promote laser efficiency and alleviate non-linear effects. The laser was pumped through a 7:1 pump combiner with seven 200-W 91x nm fiber-pigtailed wavelength-beam-combined diode-stack modules. The signal power of such a single all-fiber laser oscillator showed no evidence of roll-over, and the highest output was limited only by available pump power.

  8. Evaluation of Tritium Content and Release from Pressurized Water Reactor Fuel Cladding

    SciTech Connect

    Robinson, Sharon M.; Chattin, Marc Rhea; Giaquinto, Joseph; Jubin, Robert Thomas

    2015-09-01

    It is expected that tritium pretreatment will be required in future reprocessing plants to prevent the release of tritium to the environment (except for long-cooled fuels). To design and operate future reprocessing plants in a safe and environmentally compliant manner, the amount and form of tritium in the used nuclear fuel (UNF) must be understood and quantified. Tritium in light water reactor (LWR) fuel is dispersed between the fuel matrix and the fuel cladding, and some tritium may be in the plenum, probably as tritium labelled water (THO) or T2O. In a standard processing flowsheet, tritium management would be accomplished by treatment of liquid streams within the plant. Pretreating the fuel prior to dissolution to release the tritium into a single off-gas stream could simplify tritium management, so the removal of tritium in the liquid streams throughout the plant may not be required. The fraction of tritium remaining in the cladding may be reduced as a result of tritium pretreatment. Since Zircaloy® cladding makes up roughly 25% by mass of UNF in the United States, processes are being considered to reduce the volume of reprocessing waste for Zircaloy® clad fuel by recovering the zirconium from the cladding for reuse. These recycle processes could release the tritium in the cladding. For Zircaloy-clad fuels from light water reactors, the tritium produced from ternary fission and other sources is expected to be divided between the fuel, where it is generated, and the cladding. It has been previously documented that a fraction of the tritium produced in uranium oxide fuel from LWRs can migrate and become trapped in the cladding. Estimates of the percentage of tritium in the cladding typically range from 0–96%. There is relatively limited data on how the tritium content of the cladding varies with burnup and fuel history (temperature, power, etc.) and how pretreatment impacts its release. To gain a better understanding of how tritium in cladding

  9. Efficient laser emission from cladding waveguide inscribed in Nd:GdVO(4) crystal by direct femtosecond laser writing.

    PubMed

    Liu, Hongliang; Tan, Yang; Vázquez de Aldana, Javier R; Chen, Feng

    2014-08-01

    We report on the fabrication of depressed cladding waveguides in Nd:GdVO(4) laser crystal by using femtosecond laser inscription. The cross section of the structure is a circular shape with a diameter of 150 μm. Under the optical pump at 808 nm, the continuous wave (cw) as well as pulsed (Q-switched by graphene saturable absorber) waveguide lasing at 1064 nm has been realized, supporting guidance of both TE and TM polarizations. The maximum output power of 0.57 W was obtained in the cw regime, while the maximum pulse energy of the pulsed laser emissions was up to 19 nJ (corresponding to a maximum average output power of 0.33 W, at a resonant frequency of 18 MHz). The slope efficiencies achieved for the cw and pulsed Nd:GdVO(4) waveguide lasers were as high as 68% and 52%, respectively.

  10. Ultrasonic monitoring of material processing using clad buffer rod sensors

    NASA Astrophysics Data System (ADS)

    Ramos Franca, Demartonne

    Ultrasonic sensors and techniques are developed for in-line monitoring of polymer extrusion, cleanliness of molten metals and liquid flow speed at elevated temperature. Pulse-echo mode is used for the first two processes, while the through-transmission mode is applied in the third one. The ultrasonic probe consists of high performance clad buffer rods with different dimensions to thermally isolate the commercial ultrasonic transducer from materials at high temperature. The clad buffer rods are made of steel, polymer and ceramic. Steel clad buffer rods are introduced for in-line monitoring of polymer extrusion processes. Owing to its superior performance in pulse-echo mode, for the first time such a probe is installed and performs ultrasonic monitoring in the die of a co-extrusion machine and in the barrel section of a twin-screw extruder. It can reveal a variety of information relevant to process parameters, such as polymer layer thickness, interface location and adhesion quality, stability, or polymer composition change. For the ultrasonic monitoring of polymer processes, probes with acoustic impedance that matches that of the processed polymer may offer certain advantages such as quantitative viscoelastic evaluation; thus high temperature polymer clad buffer rods, in particular PEEK, are developed. It is demonstrated that this new probe exhibits unique advantages for in-line monitoring of the cure of epoxies and polymer extrusion process. Long steel clad buffer rods with a spherical focus lens machined at the probing end are proposed for cleanliness evaluation of molten metals. The potential of this focusing probe is demonstrated by means of high-resolution imaging and particles detection in molten zinc at temperatures higher than 600°C, using a single probe operated at pulse-echo mode. A contrapropagating ultrasonic flowmeter employing steel clad buffer rods is devised to operate at high temperature. It is demonstrated that these rods guide ultrasonic signals

  11. Multiresponse Optimization of Laser Cladding Steel + VC Using Grey Relational Analysis in the Taguchi Method

    NASA Astrophysics Data System (ADS)

    Zhang, Zhe; Kovacevic, Radovan

    2016-07-01

    Laser cladding of metal matrix composite coatings (MMCs) has become an effective and economic method to improve the wear resistance of mechanical components. The clad quality characteristics such as clad height, carbide fraction, carbide dissolution, and matrix hardness in MMCs determine the wear resistance of the coatings. These clad quality characteristics are influenced greatly by the laser cladding processing parameters. In this study, American Iron and Steel Institute (AISI) 420 + 20% vanadium carbide (VC) was deposited on mild steel with a high powder direct diode laser. The Taguchi-based Grey relational method was used to optimize the laser cladding processing parameters (laser power, scanning speed, and powder feed rate) with the consideration of multiple clad characteristics related to wear resistance (clad height, carbide volume fraction, and Fe-matrix hardness). A Taguchi L9 orthogonal array was designed to study the effects of processing parameters on each response. The contribution and significance of each processing parameter on each clad characteristic were investigated by the analysis of variance (ANOVA). The Grey relational grade acquired from Grey relational analysis was used as the performance characteristic to obtain the optimal combination of processing parameters. Based on the optimal processing parameters, the phases and microstructure of the laser-cladded coating were characterized by using x-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS).

  12. Intrathecal Pump: An Abrupt Intermittent Pump Failure.

    PubMed

    Riordan, John; Murphy, Paul

    2015-07-01

    Intrathecal baclofen is an established method of treating spasticity. However, this therapy is not without significant morbidity and mortality. The known morbidity associated with intrathecal pumps includes death, infection, and sepsis including central nervous system infection, accidental overdose, wrong drug administration as well as technical failures such as pump or battery failure, catheter migration or catheter breakage. Medtronic has issued a number of advisories, most recently in June 2013, regarding the safety of the Medtronic SynchroMed II intrathecal pumps. Sixty-four months post insertion of a SynchroMed II, model 8637; our patient was reviewed as a matter of urgency by our team, as he was complaining of worsening spasticity and pain. The device was interrogated and this indicated a motor stall at the time of interrogation. The interrogation also revealed that this was the third period of motor stall in the preceding three days. According to the patient, and consistent with our interrogation, the device had been alarming intermittently for the previous three days. He was commenced on oral baclofen overnight, which gave some improvement to his symptoms. A replacement intrathecal pump was inserted the following day. This provided the patient with his usual level of relief. The product Engineering Department at Medtronic reviewed the original pump. The patient's new intrathecal pump has been functioning uneventfully since its replacement and he continues to receive good symptom relief from his new pump. Internal inspection of the pump by the Engineering Department at Medtronic revealed corrosion of the motor gearbox. Our unit continues to retain a high level of vigilance when dealing with potential complications of intrathecal pump therapy. Supplemental oral baclofen may have a role in this setting. © 2014 International Neuromodulation Society.

  13. Liquid metal electric pump

    DOEpatents

    Abbin, Joseph P.; Andraka, Charles E.; Lukens, Laurance L.; Moreno, James B.

    1992-01-01

    An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other.

  14. Liquid metal electric pump

    DOEpatents

    Abbin, J.P.; Andraka, C.E.; Lukens, L.L.; Moreno, J.B.

    1992-01-14

    An electrical pump for pumping liquid metals to high pressures in high temperature environments without the use of magnets or moving mechanical parts. The pump employs a non-porous solid electrolyte membrane, typically ceramic, specific to the liquid metal to be pumped. A DC voltage is applied across the thickness of the membrane causing ions to form and enter the membrane on the electrically positive surface, with the ions being neutralized on the opposite surface. This action provides pumping of the liquid metal from one side of the non-porous solid electrolyte membrane to the other. 3 figs.

  15. Jet pump assisted artery

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A procedure for priming an arterial heat pump is reported; the procedure also has a means for maintaining the pump in a primed state. This concept utilizes a capillary driven jet pump to create the necessary suction to fill the artery. Basically, the jet pump consists of a venturi or nozzle-diffuser type constriction in the vapor passage. The throat of this venturi is connected to the artery. Thus vapor, gas, liquid, or a combination of the above is pumped continuously out of the artery. As a result, the artery is always filled with liquid and an adequate supply of working fluid is provided to the evaporator of the heat pipe.

  16. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, S.M.; Ward, R.L.

    1992-03-03

    This patent describes a pump for pumping a preselected quantity of fluid with each pump driving stroke from a fluid inlet port to a fluid outlet port, an inlet valve for selectively controlling fluid flow through the fluid inlet port, a pump body defining a pump bore therein, a piston slidably movable within the pump bore and having a fluid inlet end and an opposing operator end, an operator unit for reciprocating the piston within the pump bore, and a manifold interconnect with the pump body. It comprises a flow path therein extending from a manifold inlet port to a manifold outlet port, flow path being in communication with the fluid outlet port in the pump body, a purge passageway extending from the flow path to the outlet passageway, a purge valve for regulating fluid flow through the purge passageway, and a filter positioned within the manifold and extending across a portion of the flow path, the filter defining a filtered zone within the flow path adjoining the inlet port in the pump body, and an unfiltered zone within the flow path extending from the manifold inlet to the manifold outlet, such that filtered fluid enters the pump bore while unfiltered fluid bypasses the filter and passes out the manifold outlet port.

  17. Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites

    SciTech Connect

    Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

    2009-03-02

    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan (Barnes and Voke 2006). The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Hanford Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP RPP WTP 467 (Fiskum et al. 2007), eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan. • Characterizing the homogenized sample groups. • Performing parametric leaching testing on each group for compounds of interest. • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on a filtration/leaching test performed using two of the eight waste composite samples. The sample groups examined in this report were the plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR). Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, thus requiring caustic leaching. WTP RPT 167 (Snow et al. 2008) describes the homogenization, characterization, and parametric leaching activities before benchtop filtration/leaching testing of these two waste groups. Characterization and initial parametric data in that report were used to plan a single filtration/leaching test using a blend of both wastes. The test focused on filtration testing of the waste and caustic leaching for aluminum, in the form

  18. Characterization of Fuel-Cladding Bond Strength Using Laser Shock

    SciTech Connect

    James A. Smith; David L. Cottle; Barry H. Rabin

    2014-04-01

    This paper describes new laser-based capabilities for characterization of fuel-cladding bond strength in nuclear fuels, and presents preliminary results obtained from studies on as-fabricated monolithic fuel consisting of uranium-10 wt.% molybdenum alloys clad in 6061 aluminum by hot isostatic pressing. Two complementary experimental methods are employed, laser-shock testing and laser-ultrasonic imaging. Measurements are spatially localized, non-contacting and require minimum specimen preparation, and are therefore ideally suited for applications involving radioactive materials, including irradiated materials. The theoretical principles and experimental approaches employed in characterization of nuclear fuel plates are described. The ability to measure layer thicknesses, elastic properties of the constituents, and the location and nature of laser-shock induced debonds is demonstrated, and preliminary bond strength measurement results are discussed.

  19. Secondary ion mass spectrometry of irradiated nuclear fuel and cladding

    NASA Astrophysics Data System (ADS)

    Portier, S.; Brémier, S.; Walker, C. T.

    2007-06-01

    The principles and operating modes of secondary ion mass spectrometry (SIMS) are first described after which the different methods of quantification are summarised. Some current applications of SIMS in nuclear fuel and cladding research are then reviewed after briefly considering the modifications that are needed to allow a SIMS instrument to be used for the analysis of highly radioactive materials. Amongst the applications reported are the investigation of the behaviour of fission gas xenon and the volatile fission products tellurium, iodine and caesium in UO2 nuclear fuel, measurement of the radial distribution of Pu isotopes in mixed oxide (MOX) fuel and of the radial distribution of Gd isotopes in (U,Gd)O2 fuel, and determination of the distribution of Li and B in the external oxide layer on Zircaloy cladding. It is evident from the large amount of new information gained that SIMS is a powerful complementary technique to electron probe microanalysis (EPMA) in these fields of study.

  20. Clad — Automatic Differentiation Using Clang and LLVM

    NASA Astrophysics Data System (ADS)

    Vassilev, V.; Vassilev, M.; Penev, A.; Moneta, L.; Ilieva, V.

    2015-05-01

    Differentiation is ubiquitous in high energy physics, for instance in minimization algorithms and statistical analysis, in detector alignment and calibration, and in theory. Automatic differentiation (AD) avoids well-known limitations in round-offs and speed, which symbolic and numerical differentiation suffer from, by transforming the source code of functions. We will present how AD can be used to compute the gradient of multi-variate functions and functor objects. We will explain approaches to implement an AD tool. We will show how LLVM, Clang and Cling (ROOT's C++11 interpreter) simplifies creation of such a tool. We describe how the tool could be integrated within any framework. We will demonstrate a simple proof-of-concept prototype, called Clad, which is able to generate n-th order derivatives of C++ functions and other language constructs. We also demonstrate how Clad can offload laborious computations from the CPU using OpenCL.

  1. Release of fission tritium through Zircaloy-4 fuel cladding tubes

    NASA Astrophysics Data System (ADS)

    Andrieu, C.; Ravel, S.; Ducros, G.; Lemaignan, C.

    2005-12-01

    In order to analyse a potential fission tritium migration from the fuel to the coolant trough the cladding, two experiments of effusion and permeation types, have been performed on 3H release from Zry4 claddings. During the tests at 350 °C, the 3H released activities were measured at regular intervals. In both cases, very fast release rates have been obtained in the first few days, followed by more steady release rates. A correlation has been obtained between the 3H releases measured and the oxide formation kinetics after the initial burst. A mechanism of 3H transport is proposed based on the behaviour of the precipitates during the oxidation of Zry4. Applied to the conditions of PWR fuels, the measurements performed and the mechanisms considered lead to an insignificant contribution of fission tritium permeation to the total inventory of the tritium in the primary coolant.

  2. Highly birefringent photonic crystal fiber with hybrid cladding structure

    NASA Astrophysics Data System (ADS)

    Li, Jianhua; Wang, Rong; Wang, Jingyuan; Zhang, Baofu; Zhou, Hua

    2010-12-01

    A novel highly birefringent photonic crystal fiber (PCF) with hybrid cladding is proposed. In this hybrid structural PCF, some air holes of the cladding are selectively filled with high refractive index material. The increased birefringence mainly results from that the symmetry is destroyed further in the designed PCF. The birefringence is theoretically investigated with variant structural parameters and refractive index of the filled material. The plane wave expansion method (PWE) and full-vector finite-element method (FEM) are respectively employed to investigate the optical properties of the proposed PCF. The numerical results show that the designed PCF can provide high birefringence and be well tuned by the structural parameters and refractive index of the filled material. It can be used as all-fiber polarization controllers and highly sensitive sensors.

  3. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    SciTech Connect

    Cao, Guoping; Yang, Yong

    2013-12-19

    To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.

  4. Retrospective dosimetry analyses of reactor vessel cladding samples

    SciTech Connect

    Greenwood, L. R.; Soderquist, C. Z.; Fero, A. H.

    2011-07-01

    Reactor pressure vessel cladding samples for Ringhals Units 3 and 4 in Sweden were analyzed using retrospective reactor dosimetry techniques. The objective was to provide the best estimates of the neutron fluence for comparison with neutron transport calculations. A total of 51 stainless steel samples consisting of chips weighing approximately 100 to 200 mg were removed from selected locations around the pressure vessel and were sent to Pacific Northwest National Laboratory for analysis. The samples were fully characterized and analyzed for radioactive isotopes, with special interest in the presence of Nb-93m. The RPV cladding retrospective dosimetry results will be combined with a re-evaluation of the surveillance capsule dosimetry and with ex-vessel neutron dosimetry results to form a comprehensive 3D comparison of measurements to calculations performed with 3D deterministic transport code. (authors)

  5. Visual observation of fuel and clad relocation during LMFBR transients

    SciTech Connect

    Wright, S.A.; Pickard, P.S.; Schumacher, G.; Henkel, P.

    1984-01-11

    The first experiment in the jointly-sponsored (NRC-KfK) STAR experiment program was completed November 9, 1983. The STAR program investigates the transient relocation of fuel and cladding during the initiation phase of LMFBR hypothetical accidents. The name STAR is an acronym for the Sandia Transient Axial Relocation experiments. The program focuses on the key initiation phase issue of material relocation, since it dominates the reactivity input during the early phases of LOF type LMFBR accidents. The STAR experiment capsule was designed to allow the direct observation of small fuel pin bundles through an in-pile optical system. The motion of fuel and cladding during the simulated LOF are recorded on a high speed 35 mm motion picture camera.

  6. Interactions of Zircaloy Cladding with Gallium: Final Report

    SciTech Connect

    D.F. Wilson; E.T. Manneschmidt; J.F. King; J.P. Strizak; J.R. DiStefano

    1998-09-01

    The U.S. Department of Energy has established a dual-track approach to the disposition of plutonium arising from the dismantling of nuclear weapons. Both immobilization and reactor-based mixed-oxide (MOX) fuel technologies are being evaluated. The reactor-based MOX fuel option requires assessment of the potential impact of concentrations of gallium (on the order of 1 to 10 ppm), not present in conventional MOX fhel, on cladding material performance. Three previous repmts"3 identified several compatibility issues relating to the presence of gallium in MOX fuel and its possible reaction with fiel cladding. Gallium initially present in weapons-grade (WG) plutonium is largely removed during processing to produce MOX fhel. After blending the plutonium with uranium, only 1 to 10 ppm gallium is expected in the sintered MOX fuel. Gallium present as gallium oxide (G~OJ could be evolved as the suboxide (G~O). Migration of the evolved G~O and diffusion of gallium in the MOX matrix along thermal gradients could lead to locally higher concentrations of G~03. Thus, while an extremely low concentration of gallium in MOX fiel almost ensures a lack of significant interaction of gallium whh Zircaloy fhel cladding, there remains a small probability that corrosion effects will not be negligible. General corrosion in the form of surface alloying resulting from formation of intermetallic compounds between Zircaloy and gallium should be ma& limited and, therefore, superficial because of the expected low ratio of gallium to the surface area or volume of the Zircaloy cladding. Although the expected concentration of gallium is low and there is very limited volubility of gallium in zirconium, especially at temperatures below 700 "C,4 grain boundary penetration and liquid metal embrittlement (LME) are forms of localized corrosion that were also considered. One fuel system darnage mechanism, pellet clad interaction, has led to some failure of the Zircaloy cladding in light-water reactors (LWRS

  7. Modeling of MOX Fuel Pellet-Clad Interaction Using ABAQUS

    SciTech Connect

    Ambrosek, Richard G.; Pedersen, Robert C.; Maple, Amanda

    2002-07-01

    Post-irradiation examination (PIE) has indicated an increase in the outer diameter of fuel pins being irradiated in the Advanced Test Reactor (ATR) for the MOX irradiation program. The diameter increase is the largest in the region between fuel pellets. The fuel pellet was modeled using PATRAN and the model was evaluated using ABAQUS, version 6.2. The results from the analysis indicate the non-uniform clad diameter is caused by interaction between the fuel pellet and the clad. The results also demonstrate that the interaction is not uniform over the pellet axial length, with the largest interaction occurring in the region of the pellet-pellet interface. Results were obtained for an axisymmetric model and for a 1/8 pie shaped segment, using the coupled temperature-displacement solution technique. (authors)

  8. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    NASA Astrophysics Data System (ADS)

    Sponseller, D. L.; Timmons, G. A.; Bakker, W. T.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method (U.S. Patent 5,558,150). The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded (at a ratio of 13.4) to 84-mm (3.3 in.) OD X 64-mm (2.5-in.) ID tubes, and (at a ratio of 37.6) to 51-mm (2-in.) OD X 38-mm (1.5-in.) ID tubes. In all, 10 castings were produced, and 12 billets were extruded to tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm (2-in.) tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to the base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm (0.125 in.) in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3 % of the bond-line length. Cost estimates for commercial production of 51-mm (2-in.) tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes).

  9. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    SciTech Connect

    Sponseller, D.L.; Timmons, G.A.; Bakker, W.T.

    1995-12-31

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method. The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures are controlled to prevent meltback of the SS310 outer layer by the higher-melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded (at a ratio of 13.4) to 3.3-inch OD x 2.5-inch ID tubes, and (at a ratio of 37.6) to 2-inch OD x 1.5-inch ID tubes. In all, ten castings were produced, and 12 billets were extruded to tubes. For the most part, thicknesses of the cladding and tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile Properties of annealed 2-inch tubes are uniform from end to 6nd of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to the base metal, as revealed by metallography, and by two tests developed for this study: a bond hear-strength test and a twist test. In the latter test, rings 0.125 inch in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing just 2.7 percent of the bond-line length. Cost estimates OCCUPY for commercial production of 2-inch tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes).

  10. Reactor Physics Assessment of Thick Silicon Carbide Clad PWR Fuels

    DTIC Science & Technology

    2013-06-01

    the probability of cladding failure. Radiation damage to Zr causes degradation of its mechanical properties . Thermal stress, vibration, fatigue...damaging to Zr’s mechanical properties even in the absence of radiation, however radiation increases the severity of these effects —and the effect of...tends to lead to degradation of mechanical properties via formation of elements not present in the as manufactured alloy , helium production, and

  11. Liquid crystal claddings for passive temperature stabilization of silicon photonics

    NASA Astrophysics Data System (ADS)

    Ptasinski, Joanna N.; Khoo, Iam-Choon; Fainman, Yeshaiahu

    2014-10-01

    Silicon photonics allows for high density component integration on a single chip and it brings promise for low-loss, high-bandwidth data processing in modern computing systems. Owing to silicon's high positive thermo-optic coefficient, temperature fluctuations tend to degrade the device performance. This work explores passive thermal stabilization of silicon photonic devices using nematic liquid crystal (NLC) claddings, as they possess large negative thermo-optic coefficients in addition to low absorption at the telecommunication wavelengths.

  12. Stopping light by an air waveguide with anisotropic metamaterial cladding.

    PubMed

    Jiang, Tian; Zhao, Junming; Feng, Yijun

    2009-01-05

    We present a detailed study of oscillating modes in a slab waveguide with air core and anisotropic metamaterial cladding. It is shown that, under specific dielectric configurations, slow and even stopped electromagnetic wave can be supported by such an air waveguide. We propose a linearly tapped waveguide structure that could lead the propagating light to a complete standstill. Both the theoretical analysis and the proposed waveguide have been validated by full-wave simulation based on finite-difference time-domain method.

  13. DISSOLUTION OF ZIRCALOY 2 CLAD UO2 COMMERCIAL REACTOR FUEL

    SciTech Connect

    Kessinger, G.; Thompson, M.

    2009-08-07

    The primary goal of this investigation was to evaluate the effectiveness of the chop-leach process, with nitric acid solvent, to produce a nominally 300 g/L [U] and 1 M [H{sup +}] product solution. The results of this study show that this processing technique is appropriate for applications in which a low free acid and moderately high U content are desired. The 7.75 L of product solution, which was over 450 g/L in U, was successfully diluted to produce about 13 L of solvent extraction feed that was 302 g/L in U with a [H{sup +}] in the range 0.8-1.2 M. A secondary goal was to test the effectiveness of this treatment for the removal of actinides from Zircaloy cladding to produce a low-level radioactive waste (LLW) cladding product. Analysis of the cladding shows that actinides are present in the cladding at a concentration of about 5000 {eta}Ci/g, which is about 50 times greater than the acceptable transuranium element limit in low level radioactive waste. It appears that the concentration of nitric acid used for this dissolution study (initial concentration 4 M, with 10 M added as the dissolution proceeded) was inadequate to completely digest the UO{sub 2} present in the spent fuel. The mass of insoluble material collected from the initial treatments with nitric acid, 340 g, was much higher than expected, and analysis of this insoluble residue showed that it contained at least 200 g U.

  14. Modeling Explosive Cladding of Metallic Liners to Gun Tubes

    DTIC Science & Technology

    2010-01-01

    velocity of the explosive. Using the experimental Dfor the Chapman - Jouguet state and assuming the empirical v2£ is valid at seven volume expansions...process. EQUATION OF STATE The explosives used in this cladding effort have very low energy levels compared to traditional military explosives. A...impact for all the steps modeled. This indicates that a traditional Gurney assumption for final tube velocity is not accurate, as a final asymptotic

  15. Ion irradiation testing of Improved Accident Tolerant Cladding Materials

    SciTech Connect

    Anderoglu, Osman; Tesmer, Joseph R.; Maloy, Stuart A.

    2014-01-14

    This report summarizes the results of ion irradiations conducted on two FeCrAl alloys (named as ORNL A&B) for improving the accident tolerance of LWR nuclear fuel cladding. After irradiation with 1.5 MeV protons to ~0.5 to ~1 dpa and 300°C nanoindentations were performed on the cross-sections along the ion range. An increase in hardness was observed in both alloys. Microstructural analysis shows radiation induced defects.

  16. Optical Fiber Geometry: Accurate Measurement of Cladding Diameter

    PubMed Central

    Young, Matt; Hale, Paul D.; Mechels, Steven E.

    1993-01-01

    We have developed three instruments for accurate measurement of optieal fiber cladding diameter: a contact micrometer, a scanning confocal microscope, and a white-light interference microscope. Each instrument has an estimated uncertainty (3 standard deviations) of 50 nm or less, but the confocal microscope may display a 20 nm systematic error as well. The micrometer is used to generate Standard Reference Materials that are commercially available. PMID:28053467

  17. Influence of curvature on the losses of doubly clad fibers.

    PubMed

    Marcuse, D

    1982-12-01

    The loss increase of the HE(11) mode of a doubly clad (depressed-index) fiber due to constant curvature is considered. The calculations presented in this paper are based on a simplified theory. We find that for typical fibers the leakage loss of the HE(11) mode begins to increase significantly when the radius of curvature of the fiber axis reaches the 1-10-cm range.

  18. Interactions of Zircaloy cladding with gallium: 1998 midyear status

    SciTech Connect

    Wilson, D.F.; DiStefano, J.R.; Strizak, J.P.; King, J.F.; Manneschmidt, E.T.

    1998-06-01

    A program has been implemented to evaluate the effect of gallium in mixed-oxide (MOX) fuel derived from weapons-grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in a light-water reactor. The graded, four-phase experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium (Phase 1), (2) various concentrations of Ga{sub 2}O{sub 3} (Phase 2), (3) centrally heated surrogate fuel pellets with expected levels of gallium (Phase 3), and (4) centrally heated prototypic MOX fuel pellets (Phase 4). This status report describes the results of a series of tests for Phases 1 and 2. Three types of tests are being performed: (1) corrosion, (2) liquid metal embrittlement, and (3) corrosion-mechanical. These tests will determine corrosion mechanisms, thresholds for temperature and concentration of gallium that may delineate behavioral regimes, and changes in the mechanical properties of Zircaloy. Initial results have generally been favorable for the use of WG-MOX fuel. The MOX fuel cladding, Zircaloy, does react with gallium to form intermetallic compounds at {ge}300 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (parts per million) of gallium in the MOX fuel. Although continued migration of gallium into the initially formed intermetallic compound can result in large stresses that may lead to distortion, this was shown to be extremely unlikely because of the low mass of gallium or gallium oxide present and expected clad temperatures below 400 C. Furthermore, no evidence for grain boundary penetration by gallium has been observed.

  19. Interactions of zircaloy cladding with gallium -- 1997 status

    SciTech Connect

    Wilson, D.F.; DiStefano, J.R.; King, J.F.; Manneschmidt, E.T.; Strizak, J.P.

    1997-11-01

    A four phase program has been implemented to evaluate the effect of gallium in mixed oxide (MOX) fuel derived from weapons grade (WG) plutonium on Zircaloy cladding performance. The objective is to demonstrate that low levels of gallium will not compromise the performance of the MOX fuel system in LWR. This graded, four phase experimental program will evaluate the performance of prototypic Zircaloy cladding materials against: (1) liquid gallium (Phase 1), (2) various concentrations of Ga{sub 2}O{sub 3} (Phase 2), (3) centrally heated surrogate fuel pellets with expected levels of gallium (Phase 3), and (4) centrally heated prototypic MOX fuel pellets (Phase 4). This status report describes the results of an initial series of tests for phases 1 and 2. Three types of tests are being performed: (1) corrosion, (2) liquid metal embrittlement (LME), and (3) corrosion mechanical. These tests are designed to determine the corrosion mechanisms, thresholds for temperature and concentration of gallium that may delineate behavioral regimes, and changes in mechanical properties of Zircaloy. Initial results have generally been favorable for the use of WG-MOX fuel. The MOX fuel cladding, Zircaloy, does react with gallium to form intermetallic compounds at {ge} 300 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (in parts per million) of gallium in the MOX fuel. While continued migration of gallium into the initially formed intermetallic compound results in large stresses that can lead to distortion, this is also highly unlikely because of the low mass of gallium or gallium oxide present and expected clad temperatures below 400 C. Furthermore, no evidence for grain boundary penetration by gallium has been observed.

  20. Final report on accident tolerant fuel performance analysis of APMT-Steel Clad/UO₂ fuel and APMT-Steel Clad/UN-U₃Si₅ fuel concepts

    SciTech Connect

    Unal, Cetin; Galloway, Jack D.

    2014-09-12

    In FY2014 our group completed and documented analysis of new Accident Tolerant Fuel (ATF) concepts using BISON. We have modeled the viability of moving from Zircaloy to stainless steel cladding in traditional light water reactors (LWRs). We have explored the reactivity penalty of this change using the MCNP-based burnup code Monteburns, while attempting to minimize this penalty by increasing the fuel pellet radius and decreasing the cladding thickness. Fuel performance simulations using BISON have also been performed to quantify changes to structural integrity resulting from thinner stainless steel claddings. We account for thermal and irradiation creep, fission gas swelling, thermal swelling and fuel relocation in the models for both Zircaloy and stainless steel claddings. Additional models that account for the lower oxidation stainless steel APMT are also invoked where available. Irradiation data for HT9 is used as a fallback in the absence of appropriate models. In this study the isotopic vectors within each natural element are varied to assess potential reactivity gains if advanced enrichment capabilities were levied towards cladding technologies. Recommendations on cladding thicknesses for a robust cladding as well as the constitutive components of a less penalizing composition are provided. In the first section (section 1-3), we present results accepted for publication in the 2014 TOPFUEL conference regarding the APMT/UO₂ ATF concept (J. Galloway & C. Unal, Accident Tolerant and Neutronically Favorable LWR Cladding, Proceedings of WRFPM 2014, Sendai, Japan, Paper No.1000050). Next we discuss our preliminary findings from the thermo-mechanical analysis of UN-U₃Si₅ fuel with APMT clad. In this analysis we used models developed from limited data that need to be updated when the irradiation data from ATF-1 test is available. Initial results indicate a swelling rate less than 1.5% is needed to prevent excessive clad stress.

  1. Recent developments in processing HTS silver-clad Bi-2223 tapes, coils and test magnets

    SciTech Connect

    Haldar, P.; Hoehn, J.G. Jr.; Motowidlo, L.R.; Balachandran, U.; Iwasa, Y.; Yunus, M.

    1993-10-01

    Considerable progress has been made in fabricating Bi-2223 high temperature superconductor (HTS) wires and tapes with high critical current densities that are attractive for electric power and high-field magnet applications. Powder-in-tube processed silver-clad Bi-2223 short tape samples, small coils and test magnets have been fabricated and measured at liquid nitrogen (77K), pumped liquid nitrogen (64 K), liquid neon (27K) and liquid helium (4.2K) temperatures. Optimization of thermo-mechanical process parameters have yielded J{sub c}`s in the superconducting core > 4.0 {times} 10{sup 4} A/cm{sup 2} at 77K zero field and > 2.0 {times} 10{sup 5} A/cm{sup 2} at 4.2K, zero field. Long lengths (up to 70 m) of mono-core conductors were fabricated and tested to carry significant amounts of current (23 A, {approximately}15,000 A/cm{sup 2}) at liquid nitrogen temperature. Recent test magnets assembled from pancake wound coils were measured to generate magnetic fields as high as 2.6, 1.8 and 0.36 Tesla at 4.2K, 27K and 77K respectively. These results show promise towards practical utilization of HTS materials.

  2. Testing Method for External Cladding Systems - Incerc Romania

    NASA Astrophysics Data System (ADS)

    Simion, A.; Dragne, H.

    2017-06-01

    This research presents a new testing method in a natural scale for external cladding systems tested on buildings with minimum than 3 floors [1]. The testing method is unique in Romania and it is similar about many fire testing current methods from European Union states. Also, presents the fire propagation and the effect of fire smoke on the building façade composed of thermal insulation. Laboratory of testing and research for building fire safety from National Institute INCERC Bucharest, provides a test method for determining the fire performance characteristics of non-loadbearing external cladding systems and external wall insulation systems when applied to the face of a building and exposed to an external fire under controlled conditions [2]. The fire exposure is representative of an external fire source or a fully-developed (post-flashover) fire in a room, venting through an opening such as a window aperture that exposes the cladding to the effects of external flames, or an external fire source. On the future, fire tests will be experimented for answer demande a number of high-profile fires where the external facade of tall buildings provided a route for vertical fire spread.

  3. Behavior of Zr1%Nb Fuel Cladding under Accident Conditions

    SciTech Connect

    Perez-Fero, E.; Hozer, Z.; Windberg, P.; Nagy, I.; Vimi, A.; Ver, N.; Matus, L.; Kunstar, M.; Novotny, T.; Horvath, M.; Gyori, Cs.

    2007-07-01

    The behavior of the VVER fuel (E110) cladding under accident conditions has been investigated at the AEKI in order to study the role of oxidation and hydrogen uptake on the cladding embrittlement and to understand the phenomena that took place during the Paks-2 cleaning tank incident (2003). The test programme covered small scale tests and large scale tests with electrically heated 7-rod bundles in the CODEX (Core Degradation Experiment) facility. Since a hydrogen rich atmosphere could have been formed in the closed tank, the experiments were carried out in hydrogen-steam mixture. According to the results of the small scale tests, a former correlation for the ductile-brittle transitions of E110 in pure steam remained valid in hydrogen rich steam atmosphere as well. During the large scale tests the main conditions of the incident were reconstructed. The test characterized the high temperature oxidation and embrittlement of zirconium in hydrogen rich steam. The observed cladding failure phenomena and the extent of the damage of the test bundle in the quenching phase were very similar to those of the VVER assemblies in the incident. The simulation of the cleaning tank incident provided detailed information on the most probable scenario of the incident. (authors)

  4. Metallography of pitted aluminum-clad, depleted uranium fuel

    SciTech Connect

    Nelson, D.Z.; Howell, J.P.

    1994-12-01

    The storage of aluminum-clad fuel and target materials in the L-Disassembly Basin at the Savannah River Site for more than 5 years has resulted in extensive pitting corrosion of these materials. In many cases the pitting corrosion of the aluminum clad has penetrated in the uranium metal core, resulting in the release of plutonium, uranium, cesium-137, and other fission product activity to the basin water. In an effort to characterize the extent of corrosion of the Mark 31A target slugs, two unirradiated slug assemblies were removed from basin storage and sent to the Savannah River Technology Center for evaluation. This paper presents the results of the metallography and photographic documentation of this evaluation. The metallography confirmed that pitting depths varied, with the deepest pit found to be about 0.12 inches (3.05 nun). Less than 2% of the aluminum cladding was found to be breached resulting in less than 5% of the uranium surface area being affected by corrosion. The overall integrity of the target slug remained intact.

  5. Laser surface texturization for high power cladding light stripper

    NASA Astrophysics Data System (ADS)

    Berisset, Michael; Lebrun, Léo.; Faucon, Marc; Kling, Rainer; Boullet, Johan; Aguergaray, Claude

    2016-03-01

    We demonstrated herein a new type of cladding light strippers suitable for high power systems. By precisely micro-machining the surface of the fiber we create CLS with efficiencies as high as 97 % for large NA, multi-mode, cladding light (NA = 0.3), and 70 % for single-mode, low NA, light. The NA of the cladding light is reduced from 0.3 down to 0.08. The CLS exhibit a 1°C/stripped-Watt temperature elevation making them very suitable for high power applications. This fabrication method is simple and reliable. We have tested different texturization geometries on several different fibers: 20/400 from Nufern, KAGOME, and LMA 10 and LMA 15 fibers (results not shown herein) and we observed good efficiencies and temperature elevation behavior for all of them. Finally, large scale production of CLS with this method is possible since the time necessary to prepare on CLS is very small, in the order of few seconds.

  6. The behavior of powder particles in coaxial laser cladding

    NASA Astrophysics Data System (ADS)

    Yang, Nan; Dong, Hua-jun; Hu, Ping

    2010-11-01

    The metal powder flow is sprayed by a coaxial nozzle with carrying gas in laser cladding, and the powder particles are radiated to be melt metal by high power laser beam. The melting metal enters the melting pool on the substrate which is radiated by the same laser beam. The cladding layer forms, when the melting metal cool down. It is crucial to study the influences of different process parameters on the motional and thermal behavior of moving powder particles. In this paper, 2D model about a moving particle's motional and thermal behavior were established. Results show that the increasing mode of the velocities of a powder particle and the carrying gas depends on their initial velocity; the maximum value of the particle velocity appears in the middle of the nozzle exit; and the temperature of the particle rises rapidly and then falls due to the relationship between cold gas, the variation of laser intensity and its velocity and so on. The results are very helpful to design the nozzle and to select process parameters in coaxial laser cladding.

  7. Behavior of Zircaloy Cladding in the Presence of Gallium

    SciTech Connect

    DiStefano, J.R.; King, J.F.; Manneschmidt, E.T.; Strizak, J.P.; Wilson, D.F.

    1998-09-28

    The U.S. Department of Energy has established a dual-track approach to the disposition of plutonium arising from the dismantling of nuclear weapons. Both immobilization and reactor-based mixed-oxide (MOX) fuel technologies are being evaluated. The reactor-based MOX fuel option requires assessment of the potential impact of concentrations of gallium (on the order of 1 to 10 ppm), not present in conventional MOX fuel, on cladding material performance. An experimental program was designed to evaluate the performance of prototypic Zircaloy cladding materials against (1) liquid gallium, and (2) various concentrations of G~03. Three types of tests were performed: (1) corrosion, (2) liquid metal embrittlement, and (3) corrosion-mechanical. These tests were to determine corrosion mechanisms, thresholds for temperature and concentration of gallium that delineate behavioral regimes, and changes in the mechanical properties of Zircaloy. Results have generally been favorable for the use of weapons-grade (WG) MOX fhel. The Zircaloy cladding does react with gallium to form intermetallic compounds at >3000 C; however, this reaction is limited by the mass of gallium and is therefore not expected to be significant with a low level (parts per million) of gallium in the MOX fuel. Furthermore, no evidence for grain boundary penetration by gallium or liquid metal embrittlement was observed.

  8. Microbial Biofilm Growth on Irradiated, Spent Nuclear Fuel Cladding

    SciTech Connect

    S.M. Frank

    2009-02-01

    A fundamental criticism regarding the potential for microbial influenced corrosion in spent nuclear fuel cladding or storage containers concerns whether the required microorganisms can, in fact, survive radiation fields inherent in these materials. This study was performed to unequivocally answer this critique by addressing the potential for biofilm formation, the precursor to microbial-influenced corrosion, in radiation fields representative of spent nuclear fuel storage environments. This study involved the formation of a microbial biofilm on irradiated spent nuclear fuel cladding within a hot cell environment. This was accomplished by introducing 22 species of bacteria, in nutrient-rich media, to test vessels containing irradiated cladding sections and that was then surrounded by radioactive source material. The overall dose rate exceeded 2 Gy/h gamma/beta radiation with the total dose received by some of the bacteria reaching 5 × 103 Gy. This study provides evidence for the formation of biofilms on spent-fuel materials, and the implication of microbial influenced corrosion in the storage and permanent deposition of spent nuclear fuel in repository environments.

  9. Supercontinuum generation in a step-index chalcogenide fiber with AsSe2 core and As2S5 cladding

    NASA Astrophysics Data System (ADS)

    Gao, Weiqing; Xu, Qiang; Li, Xue; Zhang, Wei; Hu, Jigang; Li, Yuan; Chen, Xiangdong; Yuan, Zijun; Liao, Meisong; Li, Xia; Bi, Wanjun; Cheng, Tonglei; Suzuki, Takenobu; Ohishi, Yasutake

    2016-12-01

    We demonstrate the supercontinuum (SC) generation in a chalcogenide step-index fiber with AsSe2 core and As2S5 cladding. The characteristics of fiber are analyzed using the full-vectorial mode solver technique. The fiber has two zero-dispersion wavelengths at 2898 and 5140 nm. The evolving of SC spectra with fiber length and pump wavelength is investigated experimentally. The maximum SC range covering one octave from 1550 to 3300 nm is obtained when the 20 cm long fiber is pumped by 2000 nm pulses in normal dispersion region. The fiber can push forward the nonlinear application based on the stimulated Raman effect, stimulated Brillouin effect, four-wave mixing, supercontinuum generation, and so on in the mid-infrared waveband. The SCs are simulated by the nonlinear Schrödinger equation. The simulated results agree well with the experiments.

  10. Refractive index sensitivity enhancement of optical fiber cladding mode by depositing nanofilm via ALD technology.

    PubMed

    Zhao, Ying; Pang, Fufei; Dong, Yanhua; Wen, Jianxiang; Chen, Zhenyi; Wang, Tingyun

    2013-11-04

    The atomic layer deposition (ALD) technology is introduced to enhance the sensitivity of optical fiber cladding mode to surrounding refractive index (SRI) variation. The highly uniform Al2O nanofilm was deposited around the double cladding fiber (DCF) which presents cladding mode resonant feature. With the high refractive index coating, the cladding mode resonant spectrum was tuned. And the sensitivity enhancement for SRI sensor was demonstrated. Through adjusting the deposition cycles, a maximum sensitivity of 723 nm/RIU was demonstrated in the DCF with 2500 deposition cycles at the SRI of 1.34. Based on the analysis of cladding modes reorganization, the cladding modes transition of the coated DCF was investigated theoretically. With the high performance nanofilm coating, the proposed SRI sensor is expected to have wide applications in chemical sensors and biosensors.

  11. Method and etchant to join Ag-clad BSSCO superconducting tape

    DOEpatents

    Balachandran, U.; Iyer, A.N.; Huang, J.Y.

    1999-03-16

    A method of removing a silver cladding from high temperature superconducting material clad in silver (HTS) is disclosed. The silver clad HTS is contacted with an aqueous solution of HNO{sub 3} followed by an aqueous solution of NH{sub 4}OH and H{sub 2}O{sub 2} for a time sufficient to remove the silver cladding from the superconducting material without adversely affecting the superconducting properties of the superconducting material. A portion of the silver cladding may be masked with a material chemically impervious to HNO{sub 3} and to a combination of NH{sub 4}OH and H{sub 2}O{sub 2} to preserve the Ag coating. A silver clad superconductor is disclosed, made in accordance with the method discussed. 3 figs.

  12. Method and etchant to join ag-clad BSSCO superconducting tape

    DOEpatents

    Balachandran, Uthamalingam; Iyer, Anand N.; Huang, Jiann Yuan

    1999-01-01

    A method of removing a silver cladding from high temperature superconducting material clad in silver (HTS) is disclosed. The silver clad HTS is contacted with an aqueous solution of HNO.sub.3 followed by an aqueous solution of NH.sub.4 OH and H.sub.2 O.sub.2 for a time sufficient to remove the silver cladding from the superconducting material without adversely affecting the superconducting properties of the superconducting material. A portion of the silver cladding may be masked with a material chemically impervious to HNO.sub.3 and to a combination of NH.sub.4 OH and H.sub.2 O.sub.2 to preserve the Ag coating. A silver clad superconductor is disclosed, made in accordance with the method discussed.

  13. Characterization of SiC-SiC composites for accident tolerant fuel cladding

    NASA Astrophysics Data System (ADS)

    Deck, C. P.; Jacobsen, G. M.; Sheeder, J.; Gutierrez, O.; Zhang, J.; Stone, J.; Khalifa, H. E.; Back, C. A.

    2015-11-01

    Silicon carbide (SiC) is being investigated for accident tolerant fuel cladding applications due to its high temperature strength, exceptional stability under irradiation, and reduced oxidation compared to Zircaloy under accident conditions. An engineered cladding design combining monolithic SiC and SiC-SiC composite layers could offer a tough, hermetic structure to provide improved performance and safety, with a failure rate comparable to current Zircaloy cladding. Modeling and design efforts require a thorough understanding of the properties and structure of SiC-based cladding. Furthermore, both fabrication and characterization of long, thin-walled SiC-SiC tubes to meet application requirements are challenging. In this work, mechanical and thermal properties of unirradiated, as-fabricated SiC-based cladding structures were measured, and permeability and dimensional control were assessed. In order to account for the tubular geometry of the cladding designs, development and modification of several characterization methods were required.

  14. Analysis and optimization of process parameters in Al-SiCp laser cladding

    NASA Astrophysics Data System (ADS)

    Riquelme, Ainhoa; Rodrigo, Pilar; Escalera-Rodríguez, María Dolores; Rams, Joaquín

    2016-03-01

    The laser cladding process parameters have great effect on the clad geometry and on dilution in the single and multi-pass aluminum matrix composite reinforced with SiC particles (Al/SiCp) coatings on ZE41 magnesium alloys deposited using a high-power diode laser (HPLD). The influence of the laser power (500-700 W), scan speed (3-17 mm/s) and laser beam focal position (focus, positive and negative defocus) on the shape factor, cladding-bead geometry, cladding-bead microstructure (including the presence of pores and cracks), and hardness has been evaluated. The correlation of these process parameters and their influence on the properties and ultimately, on the feasibility of the cladding process, is demonstrated. The importance of focal position is demonstrated. The different energy distribution of the laser beam cross section in focus plane or in positive and negative defocus plane affect on the cladding-bead properties.

  15. Simulation study on laser cladding on preplaced powder layer with a tailored laser heat source

    NASA Astrophysics Data System (ADS)

    Tseng, W. C.; Aoh, J. N.

    2013-06-01

    This study proposes a tailored laser heat source model for the finite element analysis of the laser cladding process. The beam characteristics, including wavelength, beam radius, TEM mode and focusing conditions, were comprehensively considered in the heat source model. The model was integrated in a SYSWELD package to predict the temperature distribution and clad bead profile during laser cladding of preplaced cobalt powder layer on a steel substrate. Cladding process parameters were evaluated by varying the TEM mode, focusing conditions, wavelength and scanning speed. Single mode and tailored multi-mode TEMmixed laser beams were established for simulation. The numerical results were verified by performing a laser cladding experiment under the same conditions as the numerical model. The clad bead geometries predicted from the numerical simulation agreed well with those obtained from experiment. Thanks to the comprehensive feature of the proposed tailored laser heat source model, it also could be well applied to the numerical simulation of other laser material processes.

  16. An improved method for stripping cladding light in high power fiber lasers

    NASA Astrophysics Data System (ADS)

    Li, Tenglong; Wu, Juan; Sun, Yinghong; Wang, Yanshan; Ma, Yi

    2015-02-01

    In order to ensure the high power all-fiber laser reliability and excellent beam quality, it is necessary to strip the unwanted cladding light. The common method for stripping cladding light is to recoat the double cladding fiber with a high index gel, but localized heating and low thermal conductivity of the recoating gel are the prime factors limiting the power-handling capability of the cladding power stripper(CPS). An improved fabrication technique to manufacture the CPS is presented. Light stripping section of the fiber is fused with a transparent quartz tube, by applying different amount of etchant along the quartz tube, frosted surface is created and uniformly removal of the cladding light is achieved. The quartz tube is joined to water-cooled thermal enclosure tightly without the gel to avoid heat aggregation. The power-handling capability of the device is tested under 200W of cladding light, and attenuation of 20 dB is achieved.

  17. Robust cladding light stripper for high-power fiber lasers using soft metals.

    PubMed

    Babazadeh, Amin; Nasirabad, Reza Rezaei; Norouzey, Ahmad; Hejaz, Kamran; Poozesh, Reza; Heidariazar, Amir; Golshan, Ali Hamedani; Roohforouz, Ali; Jafari, S Naser Tabatabaei; Lafouti, Majid

    2014-04-20

    In this paper we present a novel method to reliably strip the unwanted cladding light in high-power fiber lasers. Soft metals are utilized to fabricate a high-power cladding light stripper (CLS). The capability of indium (In), aluminum (Al), tin (Sn), and gold (Au) in extracting unwanted cladding light is examined. The experiments show that these metals have the right features for stripping the unwanted light out of the cladding. We also find that the metal-cladding contact area is of great importance because it determines the attenuation and the thermal load on the CLS. These metals are examined in different forms to optimize the contact area to have the highest possible attenuation and avoid localized heating. The results show that sheets of indium are very effective in stripping unwanted cladding light.

  18. Observations on the behavior of surface flaws in the presence of cladding

    SciTech Connect

    Iskander, S.K.; Nanstad, R.K.

    1988-01-01

    A small crack near the inner surface of clad nuclear reactor pressure vessels (RPV) is an important consideration in the safety assessment of the structural integrity of the vessel. Four-point bend tests on large plate specimens, six clad and two unclad, were performed to determine the effect, if any, of stainless steel cladding upon the propagation of small surface cracks subjected to stress states similar to those produced by pressurized thermal shock conditions. Results of tests at temperature 10 and 60/degree/C below the nil-ductility-transition temperature (NDT) have shown that (1) a tough surface layer composed of cladding and/or heat-affected zone has arrested running flaws in clad plates under conditions where unclad plates have ruptured, and (2) the residual load-bearing capacity of clad plates with large subclad flaws significantly exceeded that of an unclad plate. 6 refs., 7 figs., 2 tabs.

  19. Technique for examining the fuel/cladding interface by TEM. [LMFBR

    SciTech Connect

    Yang, W.J.S.; Makenas, B.J.; Thomas, L.E.

    1983-05-01

    Fuel and fission-product interactions with the fuel-pin cladding is an area of concern and has been evaluated in the past principally by in-cell optical metallographic and electron-microprobe examinations. The applicability of three techniques for preparing specimens to reveal the microstructural details and local microchemistry of the fuel/cladding interface under conditions of high-resolution-scanning transmission-electron microscopy has been investigated. The specimen preparation techniques were designed to preserve the fuel/cladding interface and provide and maintain a specimen surface free from smearable alpha contamination. One of the techniques, Ni plating of a fuel cladding sample, preserved the entire cladding cross-section for examination. An Fe-oxide layer on the cladding inner surface was found in specimens prepared by this method. All three techniques of specimen preparation are described in some detail, along with their advantages and disadvantages.

  20. Cladding failure margins for metallic fuel in the integral fast reactor

    SciTech Connect

    Bauer, T.H.; Fenske, G.R.; Kramer, J.M.

    1987-01-01

    The reference fuel for Integral Fast Reactor (IFR) is a ternary U-Pu-Zr alloy with a low swelling austenitic or ferritic stainless steel cladding. It is known that low melting point eutectics may form in such metallic fuel-cladding systems which could contribute to cladding failure under accident conditions. This paper will present recent measurements of cladding eutectic penetration rates for the ternary IFR alloy and will compare these results with earlier eutectic penetration data for other fuel and cladding materials. A method for calculating failure of metallic fuel pins is developed by combining cladding deformation equations with a large strain analysis where the hoop stress is calculated using the instantaneous wall thickness as determined from correlations of the eutectic penetration-rate data. This method is applied to analyze the results of in-reactor and out-of-reactor fuel pin failure tests on uranium-fissium alloy EBR-II Mark-II driver fuel.

  1. DOE reactor-pumped laser program

    NASA Astrophysics Data System (ADS)

    Felty, James R.; Lipinski, Ronald J.; McArthur, David A.; Pickard, Paul S.

    1994-05-01

    FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. A ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night. The compact size and self-contained power also makes an RPL very suitable for ship basing so that power-beaming activities could be situated around the globe. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, wide-area deposition of diamond- like coatings, and 3-D ceramic lithography.

  2. DOE reactor-pumped laser program

    SciTech Connect

    Felty, J.R.; Lipinski, R.J.; McArthur, D.A.; Pickard, P.S.

    1993-12-31

    FALCON is a high-power, steady-state, nuclear reactor-pumped laser (RPL) concept that is being developed by the Department of Energy. The FALCON program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at at wavelengths of 585, 703, 725, 1271, 1733, 1792, 2032, 2630, 2650, and 3370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. A ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth`s shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night. The compact size and self-contained power also makes an RPL very suitable for ship basing so that power-beaming activities could be situated around the globe. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, wide-area deposition of diamond-like coatings, and 3-D ceramic lithography.

  3. Pitot heat pump

    SciTech Connect

    Grose, R.D.

    1981-12-08

    A pitot heat pump is described wherein a multi-stage pitot pump is employed as the compression means in a heat pump thermodynamic cycle. The heat pump is comprised of a multi-stage vapor pitot pump, liquid pitot pump, turbine, vaporizer, evaporator, condenser and expansion valve. The turbine is used to rotate a shaft to which the impellers of the pitot pump are attached. Refrigerant gas from the evaporator enters the first stage of the pitot pump and the impeller therein forces the refrigerant gas outwardly where it enters the narrow end of a pitot tube provided therein. The discharge end of the pitot tube is in communication with the next stage of the pitot pump. In passing through the pitot tube, the refrigerant gas expands and the centrifugal force and the kinetic energy of the gas provide the energy whereby the refrigerant gas is compressed. After the last stage, the compressed gas is transmitted to the condenser of the heat pump.

  4. Controlling centrifugal pumps

    SciTech Connect

    Driedger, W.C.

    1995-07-01

    Several options are available to match pump operating point to the process and still ensure system reliability. Assuming the pump is more than adequate for the process requirements at the moment, what is the best way to trim it to the desired operating point? There are three possible locations to place a valve: on the discharge, suction, or use a recycle valve. The paper discusses valve placement in all three options. Using the example of a pump drawing volatile hydrocarbons from a large surge vessel, the following features are discussed: a level/flow cascade loop on the pump discharge to provide process control; a check valve on the discharge downstream of the control valve to prevent reverse flow when the pump is shut down; a fire safe motor operated valve (MOV) in case of seal leakage and fires; an interlock from the MOV to stop the pump if the valve is not fully opened; a low level interlock from the vessel to stop the pump if the vessel loses its liquid seal; a pressure gauge on the suction to indicate adequate NPSHA; a thermometer on the suction to indicate potentially high vapor pressure; a minimum flow recycle loop back to the vessel; a check valve on the recycle line to prevent reverse flow when the pump is shut down, especially when the fire valve is closed; and a pressure gauge on the pump discharge to indicate that the pump is working.

  5. Processing and Characterization of Polycrystalline Yag (Yttrium Aluminum Garnet) Core-Clad Fibers - Postprint

    DTIC Science & Technology

    2015-01-01

    AFRL-RY-WP-TP-2014-0296 PROCESSING AND CHARACTERIZATION OF POLYCRYSTALLINE YAG ( YTTRIUM ALUMINUM GARNET) CORE-CLAD FIBERS -POSTPRINT...April 2013 – 1 April 2014 4. TITLE AND SUBTITLE PROCESSING AND CHARACTERIZATION OF POLYCRYSTALLINE YAG ( YTTRIUM ALUMINUM GARNET) CORE-CLAD FIBERS...of polycrystalline YAG ( Yttrium Aluminum Garnet) core-clad fibers Hyun Jun Kima,b, Geoff E. Faira*, Santeri A

  6. Development of the recovery technology for nickel superalloy blades of the aircraft engine by laser cladding

    NASA Astrophysics Data System (ADS)

    Bykovskiy, D. P.; Petrovskiy, V. N.; Polskiy, V. I.; Chirikov, S. N.; Dzhumaev, P. S.

    2016-09-01

    Development of cladding modes was performed with a superalloy nickel based powder on a flat substrate from material identical to compressor and turbine blades. Cross sections were made, and a visual inspection of the shape and the quality of the clad track as well as themetallographic analysis were performed. Microhardness of the deposition zone, chemical composition of the base, cladded metals, and the heat affected zone were determined.

  7. Parasitic suppression in large aperture disk lasers employing liquid edge claddings.

    PubMed

    Guch, S

    1976-06-01

    A liquid edge cladding system for parasitic suppression in large aperture, high gain disk laser amplifiers has been developed and tested. A near-saturated aqueous solution of Znl(2) was employed for index-matching. Adequate fluorescence absorption was demonstrated using either dissolved NiCl(2) or chrome black oxide coating applied to the disk holder. Application of liquid cladding to a 20-cm aperture disk laser amplifier increased energy storage capability by approximately 20% over conventional solder glass claddings.

  8. Theoretical analysis of swelling characteristics of cylindrical uranium dioxide fuel pins with a niobium - 1-percent-zirconium clad

    NASA Technical Reports Server (NTRS)

    Saltsman, J. F.

    1973-01-01

    The relations between clad creep strain and fuel volume swelling are shown for cylindrical UO2 fuel pins with a Nb-1Zr clad. These relations were obtained by using the computer code CYGRO-2. These clad-strain - fuel-volume-swelling relations may be used with any fuel-volume-swelling model, provided the fuel volume swelling is isotropic and independent of the clad restraints. The effects of clad temperature (over a range from 118 to 1642 K (2010 to 2960 R)), pin diameter, clad thickness and central hole size in the fuel have been investigated. In all calculations the irradiation time was 500 hours. The burnup rate was varied.

  9. Dependence of bending losses on cladding thickness in plastic optical fibers.

    PubMed

    Durana, Gaizka; Zubia, Joseba; Arrue, Jon; Aldabaldetreku, Gotzon; Mateo, Javier

    2003-02-20

    Our main goal is to provide a comprehensive explanation of the existing differences in bending losses arising from having step-index multimode plastic optical fibers with different cladding thickness and under different types of conditions, namely, the variable bend radius R, the number of fiber turns, or the fiber diameter. For this purpose, both experimental and numerical result of bending losses are presented for different cladding thicknesses and conditions. For the measurements, two cladding thicknesses have been considered: one finite and another infinite. A fiber in air has a finite cladding thickness, and rays are reflected at the cladding-air interface, whereas a fiber covered by oil is equivalent to having an infinite cladding, since the very similar refractive index of oil prevents reflections from occurring at the cladding-oil interface. For the sake of comparison, numerical simulations based on ray tracing have been performed for finite-cladding step-index multimode waveguides. The numerical results reinforce the experimental data, and both the experimental measurements and the computational simulations turn out to be very useful to explain the behavior of refracting and tunneling rays along bent multimode waveguides and along finite-cladding fibers.

  10. Special optical fiber for temperature sensing based on cladding-mode resonance.

    PubMed

    Pang, Fufei; Xiang, Wenchao; Guo, Hairun; Chen, Na; Zeng, Xianglong; Chen, Zhenyi; Wang, Tingyun

    2008-08-18

    A fiber-optic temperature sensor by using a multi-cladding special fiber is presented. It works on the basis of leaky mode resonance from fiber core to outer cladding. With the thin-thickness inner cladding, the cladding mode is strongly excited and the resonant spectrum is very sensitive to the refractive index variation of coating material. By coating the special fiber with temperature-sensitive silicone, the temperature response was investigated experimentally from -20 degrees C to 80 degrees C. The results show high temperature sensitivity (240 pm/degrees C at 20 degrees C) and good repeatability.

  11. Fabrication and testing of U–7Mo monolithic plate fuel with Zircaloy cladding

    DOE PAGES

    Pasqualini, E. E.; Robinson, A. B.; Porter, D. L.; ...

    2016-07-15

    The Materials Management and Minimization program is developing fuel designs to replace highly enriched fuel with fuels of low enrichment. In the most challenging cases, U–(7–10wt%)Mo monolithic plate fuel are proposed. The chosen design includes aluminum-alloy cladding, which provides some challenges in fabrication and fuel/cladding interaction in service. We investigated zircaloy cladding, specifically Zry–4as an alternative cladding, and development of a fabrication method was performed by researchers with the Comisión Nacionalde Energia Atómica (CNEA) in Argentina, resulting in test fuel plates (Zry–4 clad U–7Mo) which were subsequently tested in the Advanced Test Reactor in Idaho. Because Zry–4 and U–(7–10)Mo havemore » similar high-temperature mechanical properties, fabrication was simplified in that the fuel foil and cladding could be co-rolled and bonded. The challenge was to prevent a thermal-expansion mismatch which could destroy the fuel/cladding bond before complete bonding was achieved; the solution was to prevent the composites from cooling significantly between roll passes. Our final product performed very well in-reactor, showing good bonding, very little fuel/cladding interaction, either from fabrication or in-reactor testing, and little swelling, especially no detectable heterogeneous bubble formation at the fuel/cladding interface tested to a fission density of up to 2.54E+21« less

  12. Fabrication and testing of U–7Mo monolithic plate fuel with Zircaloy cladding

    SciTech Connect

    Pasqualini, E. E.; Robinson, A. B.; Porter, D. L.; Wachs, D. M.; Finlay, M. R.

    2016-07-15

    The Materials Management and Minimization program is developing fuel designs to replace highly enriched fuel with fuels of low enrichment. In the most challenging cases, U–(7–10wt%)Mo monolithic plate fuel are proposed. The chosen design includes aluminum-alloy cladding, which provides some challenges in fabrication and fuel/cladding interaction in service. We investigated zircaloy cladding, specifically Zry–4as an alternative cladding, and development of a fabrication method was performed by researchers with the Comisión Nacionalde Energia Atómica (CNEA) in Argentina, resulting in test fuel plates (Zry–4 clad U–7Mo) which were subsequently tested in the Advanced Test Reactor in Idaho. Because Zry–4 and U–(7–10)Mo have similar high-temperature mechanical properties, fabrication was simplified in that the fuel foil and cladding could be co-rolled and bonded. The challenge was to prevent a thermal-expansion mismatch which could destroy the fuel/cladding bond before complete bonding was achieved; the solution was to prevent the composites from cooling significantly between roll passes. Our final product performed very well in-reactor, showing good bonding, very little fuel/cladding interaction, either from fabrication or in-reactor testing, and little swelling, especially no detectable heterogeneous bubble formation at the fuel/cladding interface tested to a fission density of up to 2.54E+21

  13. Analysis of unclad and sub-clad semi-elliptical flaws in pressure vessel steels

    SciTech Connect

    Irizarry-Quinones, H.; Macdonald, B.D.; McAfee, W.J.

    1996-06-01

    This study was conducted to support warm prestressing experiments on unclad and sub-clad flawed beams loaded in pure bending. Two cladding yield strengths were investigated: 0.6 Sy and 0.8 Sy, where Sy is the yield strength of the base metal. Cladding and base metal were assumed to be stress free at the stress relief temperature for the 3D elastic-plastic finite element analysis used to model the experiments. The model results indicated that when cooled from the stress relief temperature, the cladding was put in tension due to its greater coefficient of thermal expansion. When cooled, the cladding exhibited various amounts of tensile yielding. The degree of yielding depended on the amount of cooling and the strength of the cladding relative to that of the base metal. When subjected to tensile bending stress, the sub-clad flaw elastic-plastic stress intensity factor, K{sub I}(J), was at first dominated by crack closing force due to tensile yielding in the cladding. Thus, imposed loads initially caused no increase in K{sub I}(J) near the clad-base interface. However, K{sub I}(J) at the flaw depth was little affected. When the cladding residual stress was overcome, K{sub I}(J) gradually increased until the cladding began to flow. Thereafter, the rate at which K{sub I}(J) increased with load was the same as that of an unclad beam. A plastic zone corrected K{sub I} approximation for the unclad flaw was found by the superposition of standard Newman and Raju solutions with those due to a cladding crack closure force approximated by the Kaya and Erdogan solution. These elastic estimates of the effect of cladding in reducing the crack driving force were quite in keeping with the 3D elastic-plastic finite element solution for the sub-clad flaw. The results were also compared with the analysis of clad beam experiments by Keeney and the conclusions by Miyazaki, et al. A number of sub-clad flaw specimens not subjected to warm prestressing were thought to have suffered degraded

  14. Microstructure and Abrasive Wear Performance of Ni-Wc Composite Microwave Clad

    NASA Astrophysics Data System (ADS)

    Bansal, Amit; Zafar, Sunny; Sharma, Apurbba Kumar

    2015-10-01

    In the present work, Ni-WC powder was deposited on mild steel substrate to develop clads through microwave hybrid heating technique. The cladding trials were carried out in an industrial microwave applicator at 1.1 kW for 540 s. The Ni-WC composite clads were characterized for microstructure and abrasive wear performance through combination of x-ray diffraction, electron and optical microscopy, microhardness, and wear tests. Phase analysis of the Ni-WC clad indicated the presence of stable carbides such as WC, W2C, Ni2W4C, and Fe6W6C. The microstructure study of the clad layer revealed the presence of a uniformly distributed interlocked WC-based reinforcement embedded in the Ni-based matrix. The average Vicker's microhardness in the clad layer was observed to be 1028 ± 90 HV, which was approximately three times the microhardness of the substrate. Abrasive wear resistance of the microwave clads was superior to the MS substrate. Abrasion was the main wear mechanism in the Ni-WC clads and the substrate samples. However, the presence of WC-based reinforcement in the composite clads reduced microcutting, resulting in enhanced wear resistance.

  15. Optical Measurement of Forming Limit and Formability of Cu/Al Clad Metals

    NASA Astrophysics Data System (ADS)

    Sun, Tao; Liang, Jin; Guo, Xiang; Ren, Maodong; Wang, Lizhong

    2015-04-01

    A digital image deformation measurement and analysis control system (XJTUDIC 8.0) was employed to measure the forming limit strain for Cu/Al clad metals produced via explosive welding technique. A contrast test between the digital image correlation (DIC) method and the conventional grid method was also implemented using the SPCC sheet metal forming limit test. The effect of heat treatment and contact status on forming limit was discussed based on the forming limit strain of Cu/Al clad metals. The interfacial and fracture structures were analyzed using scanning electron microscopy. The fracture site was predicted by finite element method. Results demonstrate that the forming limit curve of Cu/Al clad metals through DIC is more likely to reflect the formability of SPCC accurately. The forming limit of the clad with Al in the inner layer is higher than that of the clad with Cu in the inner layer. The formability of the annealed clads is superior to that of the non-annealed clads. The local interface failure induces the microcracks in Cu/Al clad metals during the forming process, which could be the main failure mode. With the finite element method, the fracture location of Cu/Al clad metals caused by uniaxial tensile during the forming limit test using DIC method is predicted accurately.

  16. Formation quality optimization of laser hot wire cladding for repairing martensite precipitation hardening stainless steel

    NASA Astrophysics Data System (ADS)

    Wen, Peng; Feng, Zhenhua; Zheng, Shiqing

    2015-01-01

    Laser cladding is an advantaged repairing technology due to its low heat input and high flexibility. With preheating wire by resistance heat, laser hot wire cladding shows better process stability and higher deposition efficiency compared to laser cold wire/powder cladding. Multi-pass layer were cladded on the surface of martensite precipitation hardening stainless steel FV520B by fiber laser with ER410NiMo wire. Wire feed rate and preheat current were optimized to obtain stable wire transfer, which guaranteed good formation quality of single pass cladding. Response surface methodology (RSM) was used to optimize processing parameters and predict formation quality of multi-pass cladding. Laser power P, scanning speed Vs, wire feed rate Vf and overlap ratio η were selected as the input variables, while flatness ratio, dilution and incomplete fusion value as the responses. Optimal clad layer with flat surface, low dilution and no incomplete fusion was obtained by appropriately reducing Vf, and increasing P, Vs and η. No defect like pore or crack was found. The tensile strength and impact toughness of the clad layer is respectively 96% and 86% of those of the substrate. The clad layer showed nonuniform microstructure and was divided into quenched areas with coarse lath martensite and tempered areas with tempered martensite due to different thermal cycles in adjacent areas. The tempered areas showed similar hardness to the substrate.

  17. Corrosion Resistance of Laser Clads of Inconel 625 and Metco 41C

    NASA Astrophysics Data System (ADS)

    Němeček, Stanislav; Fidler, Lukáš; Fišerová, Pavla

    The present paper explores the impact of laser cladding parameters on the corrosion behaviour of the resulting surface. Powders of Inconel 625 and austenitic Metco 41C steel were deposited on steel substrate. It was confirmed that the level of dilution has profound impact on the corrosion resistance and that dilution has to be minimized. However, the chemical composition of the cladding is altered even in the course of the cladding process, a fact which is related to the increase in the substrate temperature. The cladding process was optimized to achieve maximum corrosion resistance. The results were verified and validated using microscopic observation, chemical analysis and corrosion testing.

  18. Development of data base with mechanical properties of un- and pre-irradiated VVER cladding

    SciTech Connect

    Asmolov, V.; Yegorova, L.; Kaplar, E.; Lioutov, K.; Smirnov, V.; Prokhorov, V.; Goryachev, A.

    1998-03-01

    Analysis of recent RIA test with PWR and VVER high burnup fuel, performed at CABRI, NSRR, IGR reactors has shown that the data base with mechanical properties of the preirradiated cladding is necessary to interpret the obtained results. During 1997 the corresponding cycle of investigations for VVER clad material was performed by specialists of NSI RRC KI and RIAR in cooperation with NRC (USA), IPSN (France) in two directions: measurements of mechanical properties of Zr-1%Nb preirradiated cladding versus temperature and strain rate; measurements of failure parameters for gas pressurized cladding tubes. Preliminary results of these investigations are presented in this paper.

  19. Orientation-Dependent Displacement Sensor Using an Inner Cladding Fiber Bragg Grating

    PubMed Central

    Yang, Tingting; Qiao, Xueguang; Rong, Qiangzhou; Bao, Weijia

    2016-01-01

    An orientation-dependent displacement sensor based on grating inscription over a fiber core and inner cladding has been demonstrated. The device comprises a short piece of multi-cladding fiber sandwiched between two standard single-mode fibers (SMFs). The grating structure is fabricated by a femtosecond laser side-illumination technique. Two well-defined resonances are achieved by the downstream both core and cladding fiber Bragg gratings (FBGs). The cladding resonance presents fiber bending dependence, together with a strong orientation dependence because of asymmetrical distribution of the “cladding” FBG along the fiber cross-section. PMID:27626427

  20. Pump isolation valve

    DOEpatents

    Kinney, Calvin L.; Wetherill, Todd M.

    1983-08-02

    The pump isolation valve provides a means by which the pump may be selectively isolated from the remainder of the coolant system while being compatible with the internal hydraulic arrangement of the pump during normal operation of the pump. The valve comprises a valve cylinder disposed around the pump and adjacent to the last pump diffuser with a turning vane attached to the lower end of the valve cylinder in a manner so as to hydraulically match with the discharge diffuser. The valve cylinder is connected to a drive means for sliding the valve cylinder relative to the diffuser support cylinder so as to block flow in either direction through the discharge diffuser when the valve is in the closed position and to aid in the flow of the coolant from the discharge diffuser by means of the turning vane when the valve is in the open position.

  1. DIRECT CURRENT ELECTROMAGNETIC PUMP

    DOEpatents

    Barnes, A.H.

    1957-11-01

    An improved d-c electromagnetic pump is presented in which the poles, and consequently the magetic gap at the poles, are tapered to be wider at the upstream end. In addition, the cross section of the tube carryiQ the liquid metal is tapered so that the velocity of the pumped liquid increases in the downstream direction at a rate such that the counter-induced voltage in the liquid metal remains constant as it traverses the region between the poles. This configuration compensates for the distortion of the magnetic field caused by the induced voltage that would otherwise result in the lowering of the pumping capacity. This improved electromagnetic pump as practical application in the pumping of liquid metal coolants for nuclear reactors where conventional positive displacement pumps have proved unsatisfactory due to the high temperatures and the corrosive properties of the liquid metals involved.

  2. Rotary blood pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J. (Inventor); Akkerman, James W. (Inventor); Aber, Greg S. (Inventor); Vandamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1993-01-01

    A rotary blood pump is presented. The pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial, and radial clearances of the blades associated with the flow straightener, inducer portion, impeller portion, and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with crosslinked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  3. Electrokinetic pumps and actuators

    SciTech Connect

    Phillip M. Paul

    2000-03-01

    Flow and ionic transport in porous media are central to electrokinetic pumping as well as to a host of other microfluidic devices. Electrokinetic pumping provides the ability to create high pressures (to over 10,000 psi) and high flow rates (over 1 mL/min) with a device having no moving parts and all liquid seals. The electrokinetic pump (EKP) is ideally suited for applications ranging from a high pressure integrated pump for chip-scale HPLC to a high flow rate integrated pump for forced liquid convection cooling of high-power electronics. Relations for flow rate and current fluxes in porous media are derived that provide a basis for analysis of complex microfluidic systems as well as for optimization of electrokinetic pumps.

  4. A compact cryogenic pump

    SciTech Connect

    Li, Gang; Caldwell, Shane; Clark, Jason A.; Gulick, Sidney; Hecht, Adam; Lascar, Daniel D.; Levand, Tony; Morgan, Graeme; Orford, Rodney; Savard, Guy; Sharma, Kumar S.; Van Schelt, Jonathon

    2016-04-01

    A centrifugal cryogenic pump has been designed at Argonne National Laboratory to circulate liquid nitrogen (LN2) in a closed circuit allowing the recovery of excess fluid. The pump can circulate LN2 at rates of 2-10 L/min, into a head of 0.5-3 m. Over four years of laboratory use the pump has proven capable of operating continuously for 50-100 days without maintenance.

  5. Pumps, Centrifugal and Reciprocating

    DTIC Science & Technology

    2011-04-27

    reciprocating pumps. 15. SUBJECT TERMS Centrifugal pump Total discharge head Reciprocating pump Total suction head Head 16. SECURITY ... CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES 40 19a. NAME OF RESPONSIBLE PERSON a. REPORT B...Satisfy the needs of MIL-STD-4612. High-Altitude Electromagnetic Pulse ( HEMP ) Test Facility Satisfy the needs of MIL-STD-461. Rail Impact Test

  6. Detection of pump degradation

    SciTech Connect

    Greene, R.H.; Casada, D.A.; Ayers, C.W.

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  7. Fakir fuel pump

    NASA Technical Reports Server (NTRS)

    1922-01-01

    In designing the Fakir fuel pump, the fundamental idea was to obtain a simple and reliable method of conveying the fuel from a low tank to the carburetor, with the avoidance of the faults of all former methods and the simultaneous warming of the fuel by means of the heat of compression generated. The principle of the Fakir fuel pump rests on the well-known principle of the diaphragm pump, which must be suitably adapted to the present purpose.

  8. A compact cryogenic pump

    NASA Astrophysics Data System (ADS)

    Li, Gang; Caldwell, Shane; Clark, Jason A.; Gulick, Sidney; Hecht, Adam; Lascar, Daniel D.; Levand, Tony; Morgan, Graeme; Orford, Rodney; Savard, Guy; Sharma, Kumar S.; Van Schelt, Jonathon

    2016-04-01

    A centrifugal cryogenic pump has been designed at Argonne National Laboratory to circulate liquid nitrogen (LN2) in a closed circuit allowing the recovery of excess fluid. The pump can circulate LN2 at rates of 2-10 L/min, into a head of 0.5-3 m. Over four years of laboratory use the pump has proven capable of operating continuously for 50-100 days without maintenance.

  9. Champagne Heat Pump

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  10. Submersible sodium pump

    DOEpatents

    Brynsvold, G.V.; Lopez, J.T.; Olich, E.E.; West, C.W.

    1989-11-21

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates. 14 figs.

  11. Submersible sodium pump

    DOEpatents

    Brynsvold, Glen V.; Lopez, John T.; Olich, Eugene E.; West, Calvin W.

    1989-01-01

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates.

  12. Fuel injection pump

    SciTech Connect

    Miyaki, M.

    1986-01-07

    This patent describes a fuel injection pump for delivering fuel to the cylinders of an internal combustion engine consisting of: a pump housing with a fuel chamber therein to which fuel is supplied from a fuel tank; means for compressing fuel in the pump chamber and delivering the compressed fuel to the engine cylinders with such means including a pump plunger adapted to be reciprocated so as to introduce fuel into the pump chamber and to pressurize the introduced fuel; spill means for spilling to a low-pressure side on a fuel tank side the compressed fuel which was pressurized in the pump chamber to be delivered from the pump chamber to the engine cylinders, the spill mechanism including a spill passage communicating with the pump chamber and including a solenoid valve located in the spill passage for opening and closing the spill passage with predetermined timing; escape for allowing the compressed fuel pressurized in the pump chamber to escape to the low-pressure side of the fuel tank side.

  13. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1995-04-01

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous special vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Pump head and flow rate are also monitored, per code requirements. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition; advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  14. Remotely operable peristaltic pump

    NASA Technical Reports Server (NTRS)

    Belew, R. R. (Inventor)

    1986-01-01

    A peristaltic pump is disclosed which includes a roller assembly on which is mounted a series of pump rollers. As the roller assembly is rotated by a drive gear the pump rollers are driven in reverse rotation by means of a stationary ring gear and pump roller gears. An upper pressure shoe plate and a lower pressure shoe plate are positioned above sets of flexible tubing. The tubing is sandwiched between the pressure shoe plates and the pump rollers. A highly compact pump is provided having twice as many fluid channel lines as is conventional. The peristaltic pump device may be remotely operated by means of a rotary actuator which rotates a driving hub to move the shoe plates by means of eccentrically mounted links. The pressure shoe plates may be moved by the rotary actuator to a loaded position in which the fluid lines are pinched by the pump rollers and fluid is pumped to an unloaded position in which the fluid lines are maintained in an undeformed, uncrimped configuration so that no creases or crimps are set into the fluid lines during periods of prolonged nonuse.

  15. Thermomechanical piston pump development

    NASA Technical Reports Server (NTRS)

    Sabelman, E. E.

    1971-01-01

    A thermally powered reciprocating pump has been devised to replace or augment an electric pump for the transport of temperature-control fluid on the Thermoelectric Outer Planet Spacecraft (TOPS). The thermally powered pump operates cyclically by extracting heat energy from the fluid by means of a vapor-pressure expansion system and by using the heat to perform the mechanical work of pumping. A feasibility test unit has been constructed to provide an output of 7 cu in during a 10- to 100-second cycle. It operates with a fluid input temperature of 200 to 300 F and a heat sink temperature of 0 to 30 F.

  16. [Portable peristaltic perfusion pumps].

    PubMed

    Magallón Pedrera, I; Soto Torres, I

    1999-11-01

    Portable peristaltic perfusion pumps allow one to administer pharmaceuticals in hospitals as well as in primary health care centers and furthermore these pumps present multiple advantages for patients and their families since they make it possible to carry out treatment in a patient's home while at the same time lowering the costs involved. The authors analyze the most out standing aspects of portable peristaltic perfusion pumps along with their characteristics, installation, programming, and how to turn them on; in addition, the authors list the maintenance care which these pumps require.

  17. Minimize pump downtime

    SciTech Connect

    Myers, R.D.

    1995-06-01

    In refineries and petrochemical plants, centrifugal pumps usually lead the list of equipment that is most susceptible to failure. Using guidelines, maintenance mechanics can improve troubleshooting methods when investigating pump bedplates, underlying concrete foundations and grouting problems. Too often, mechanics may improperly diagnose a misalignment--caused by grouting problems--as an unbalance or a bearing-wearing problem when troubleshooting pump failure. Result: bearing, shaft and seal failures occur from a flawed maintenance procedure. Identifying mounting-surface problems can improve pump performance and decrease unit downtime.

  18. Resonance wave pumping: wave mass transport pumping

    NASA Astrophysics Data System (ADS)

    Carmigniani, Remi; Violeau, Damien; Gharib, Morteza

    2016-11-01

    It has been previously reported that pinching at intrinsic resonance frequencies a valveless pump (or Liebau pump) results in a strong pulsating flow. A free-surface version of the Liebau pump is presented. The experiment consists of a closed tank with a submerged plate separating the water into a free-surface and a recirculation section connected through two openings at each end of the tank. A paddle is placed at an off-centre position at the free-surface and controlled in a heaving motion with different frequencies and amplitudes. Near certain frequencies identified as resonance frequencies through a linear potential theory analysis, the system behaves like a pump. Particle Image Velocimetry (PIV) is performed in the near free surface region and compared with simulations using Volume of Fluid (VOF) method. The mean eulerian mass flux field (ρ) is extracted. It is observed that the flow is located in the vicinity of the surface layer suggesting Stokes Drift (or Wave Mass Transport) is the source of the pumping. A model is developped to extend the linear potential theory to the second order to take into account these observations. The authors would like to acknowledge the Gordon and Betty Moore Foundation for their generous support.

  19. Well-pump alignment system

    DOEpatents

    Drumheller, Douglas S.

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  20. Liquid pump for astronaut cooling

    NASA Technical Reports Server (NTRS)

    Carson, M. A.

    1972-01-01

    The Apollo portable life support system water-recirculation pump used for astronaut cooling is described. The problems associated with an early centrifugal pump and how these problems were overcome by the use of a new diaphragm pump are discussed. Performance comparisons of the two pump designs are given. Developmental problems and flight results with the diaphragm pump are discussed.

  1. Reactivity Initiated Accident Simulation to Inform Transient Testing of Candidate Advanced Cladding

    SciTech Connect

    Brown, Nicholas R; Wysocki, Aaron J; Terrani, Kurt A

    2016-01-01

    Abstract. Advanced cladding materials with potentially enhanced accident tolerance will yield different light water reactor performance and safety characteristics than the present zirconium-based cladding alloys. These differences are due to different cladding material properties and responses to the transient, and to some extent, reactor physics, thermal, and hydraulic characteristics. Some of the differences in reactors physics characteristics will be driven by the fundamental properties (e.g., absorption in iron for an iron-based cladding) and others will be driven by design modifications necessitated by the candidate cladding materials (e.g., a larger fuel pellet to compensate for parasitic absorption). Potential changes in thermal hydraulic limits after transition from the current zirconium-based cladding to the advanced materials will also affect the transient response of the integral fuel. This paper leverages three-dimensional reactor core simulation capabilities to inform on appropriate experimental test conditions for candidate advanced cladding materials in a control rod ejection event. These test conditions are using three-dimensional nodal kinetics simulations of a reactivity initiated accident (RIA) in a representative state-of-the-art pressurized water reactor with both nuclear-grade iron-chromium-aluminum (FeCrAl) and silicon carbide based (SiC-SiC) cladding materials. The effort yields boundary conditions for experimental mechanical tests, specifically peak cladding strain during the power pulse following the rod ejection. The impact of candidate cladding materials on the reactor kinetics behavior of RIA progression versus reference zirconium cladding is predominantly due to differences in: (1) fuel mass/volume/specific power density, (2) spectral effects due to parasitic neutron absorption, (3) control rod worth due to hardened (or softened) spectrum, and (4) initial conditions due to power peaking and neutron transport cross sections in the

  2. 33. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING PLAN AND LOCATION OF PROPOSED ADDITIONS, METROPOLITAN WATER AND SEWERAGE BOARD, METROPOLITAN SEWERAGE WORKS, JULY 1908. Aperture card 6417. - Deer Island Pumping Station, Boston, Suffolk County, MA

  3. 32. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    32. PLAN OF DEER ISLAND PUMPING STATION SHOWING EXISTING PUMPING PLANT AND LOCATION OF PROPOSED ADDITIONS, JULY 1898 SHEET NO. 1. Aperture card 4966-1 - Deer Island Pumping Station, Boston, Suffolk County, MA

  4. Looking south at boiler feedwater pumps (steam turbine pump on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking south at boiler feedwater pumps (steam turbine pump on left, electric motor pump on right). - Wheeling-Pittsburgh Steel Corporation, Allenport Works, Boiler House, Route 88 on West bank of Monongahela River, Allenport, Washington County, PA

  5. 98. VIEW OF PUMPS FROM NORTH. MILL SOLUTION PUMP No. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    98. VIEW OF PUMPS FROM NORTH. MILL SOLUTION PUMP No. 2 IN FOREGROUND, ABANDONED BARREN SOLUTION PUMP BEYOND. AGITATOR No. 1 IN BACKGROUND. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  6. Q-switched double-clad Ytterbium-doped fiber laser using MoS2 flakes saturable absorber

    NASA Astrophysics Data System (ADS)

    Tey, K. L.; Rahman, M. F. A.; Rosol, A. H. A.; Rusdi, M. F. M.; Mahyuddin, M. B. H.; Harun, S. W.; Latiff, A. A.

    2017-06-01

    By sandwiching MoS2 thin flakes between two fiber ferrule connectors in the ring cavity, we successfully demonstrate the passive Q-switched fiber laser operation. The cavity consists of all-fiber double-clad ytterbium-doped fiber (YDF) as a gain medium and MoS2 tape as a saturable absorber (SA). The SA was prepared from a commercial MoS2 crystal (~ 99.8 % purity) through mechanical exfoliation process. A piece of 1 mm x 1 mm tape contains MoS2 thin flakes was sandwiched between two fiber connectors. By controlling loss and gain in the cavity, stable Q-switching operation were generated. The repetition rate was tunable from 4.8 kHz to 17.2 kHz as the pump power is varied from 753 mW to 1133 mW. The obtained pulse width is also narrowed from 21.3 µs to 10.44 µs with the same variation of pump power.

  7. Some recent studies on laser cladding and dissimilar welding

    NASA Astrophysics Data System (ADS)

    Kaul, Rakesh; Ganesh, P.; Paul, C. P.; Albert, S. K.; Mudali, U. Kamachi; Nath, A. K.

    2006-01-01

    Indigenous development of high power CO II laser technology and industrial application of lasers represent two important mandates of the laser program, being pursued at Centre for Advanced Technology (CAT), India. The present paper describes some of the important laser material processing studies, involving cladding and dissimilar welding, performed in authors' laboratory. The first case study describes how low heat input characteristics of laser cladding process has been successfully exploited for suppressing dilution in "Colmonoy6" (a nickel-base hardfacing alloy) deposits on austenitic stainless steel components. Crack free hardfaced deposits were obtained by controlling heating and cooling rates associated with laser treatment. The results show significant advantage over Colmonoy 6 deposits made by GTAW, where a 2.5 mm thick region of dilution (with reduced hardness) develops next to substrateiclad interface. The next work involves laser-assisted deposition of graded "Stellite6" (a Co-base hardfacing alloy) with smooth transition in chemical composition and hardness for enhanced resistance against cracking, esp. under thermal cycling conditions. The following two case studies demonstrate significant improvement in corrosion properties of type 304L stainless steel by laser surface alloying, achieved through cladding route. The following case study demonstrates engineering of fusion zone microstructure of end plug dissimilar weld (between alloy D9 and type 3 16M stainless steel) by controlled preferential displacement of focused laser beam, which, in-turn, enhanced its resistance against solidification cracking. Crater appearing at the termination point of laser weld is also eliminated by ramping of laser power towards the end of laser welding. The last case study involves engineering of fusion zone microstructure of dissimilar laser weld between type 304 austenitic stainless steel and stabilized 17%Cr ferritic stainless steel by controlling welding parameters.

  8. Fabrication of a tantalum-clad tungsten target for LANSCE

    NASA Astrophysics Data System (ADS)

    Nelson, A. T.; O'Toole, J. A.; Valicenti, R. A.; Maloy, S. A.

    2012-12-01

    Development of a solid state bonding technique suitable to clad tungsten targets with tantalum was completed to improve operation of the Los Alamos Neutron Science Centers spallation target. Significant deterioration of conventional bare tungsten targets has historically resulted in transfer of tungsten into the cooling system through corrosion resulting in increased radioactivity outside the target and reduction of delivered neutron flux. The fabrication method chosen to join the tantalum cladding to the tungsten was hot isostatic pressing (HIP) given the geometry constraints of a cylindrical assembly and previous success demonstrated at KENS. Nominal HIP parameters of 1500 °C, 200 MPa, and 3 h were selected based upon previous work. Development of the process included significant surface engineering controls and characterization given tantalums propensity for oxide and carbide formation at high temperatures. In addition to rigorous acid cleaning implemented at each step of the fabrication process, a three layer tantalum foil gettering system was devised such that any free oxygen and carbon impurities contained in the argon gas within the HIP vessel was mitigated to the extent possible before coming into contact with the tantalum cladding. The result of the numerous controls and refined techniques was negligible coarsening of the native Ta2O5 surface oxide, no measureable oxygen diffusion into the tantalum bulk, and no detectable carburization despite use of argon containing up to 5 ppm oxygen and up to 40 ppm total CO, CO2, or organic contaminants. Post bond characterization of the interface revealed continuous bonding with a few microns of species interdiffusion.

  9. Improved LWR Cladding Performance by EPD Surface Modification Technique

    SciTech Connect

    Corradini, Michael; Sridharan, Kumar

    2012-11-26

    This project will utilize the electro-phoretic deposition technique (EPD) in conjunction with nanofluids to deposit oxide coatings on prototypic zirconium alloy cladding surfaces. After demonstrating that this surface modification is reproducible and robust, the team will subject the modified surface to boiling and corrosion tests to characterize the improved nucleate boiling behavior and superior corrosion performance. The scope of work consists of the following three tasks: The first task will employ the EPD surface modification technique to coat the surface of a prototypic set of zirconium alloy cladding tube materials (e.g. Zircaloy and advanced alloys such as M5) with a micron-thick layer of zirconium oxide nanoparticles. The team will characterize the modified surface for uniformity using optical microscopy and scanning-electron microscopy, and for robustness using standard hardness measurements. After zirconium alloy cladding samples have been prepared and characterized using the EPD technique, the team will begin a set of boiling experiments to measure the heat transfer coefficient and critical heat flux (CHF) limit for each prepared sample and its control sample. This work will provide a relative comparison of the heat transfer performance for each alloy and the surface modification technique employed. As the boiling heat transfer experiments begin, the team will also begin corrosion tests for these zirconium alloy samples using a water corrosion test loop that can mimic light water reactor (LWR) operational environments. They will perform extended corrosion tests on the surface-modified zirconium alloy samples and control samples to examine the robustness of the modified surface, as well as the effect on surface oxidation

  10. 35CrMo steel surface by laser cladding Fe-based WC composite coating performance analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Houming; Zhang, Haomin; Qin, Hengfeng

    2014-12-01

    The laser cladding technique in 35CrMo steel substrate prepared with different dosage under WC iron-based alloy cladding.Research the effects of different cladding WC addition on surface morphology, microstructure, microhardness and wear properties. The results show that 5% and 10% WC added amount of the surface quality of the cladding layer is preferably 15 % and 25 % of the volume of the WC surface of the cladding layer with varying degrees of cracks and pores, WC adding cladding layer can significantly improve the hardness. Through analysis we draw the conculation that,with 10% WC addition of iron-based alloy cladding the microhardness is 4.2 times the substrate , the relative wear resistance increased 4.1 than the substrate , enabling optimum cladding friction and wear properties.

  11. Pump apparatus including deconsolidator

    DOEpatents

    Sonwane, Chandrashekhar; Saunders, Timothy; Fitzsimmons, Mark Andrew

    2014-10-07

    A pump apparatus includes a particulate pump that defines a passage that extends from an inlet to an outlet. A duct is in flow communication with the outlet. The duct includes a deconsolidator configured to fragment particle agglomerates received from the passage.

  12. Breastfeeding FAQs: Pumping

    MedlinePlus

    ... Habits for TV, Video Games, and the Internet Breastfeeding FAQs: Pumping KidsHealth > For Parents > Breastfeeding FAQs: Pumping Print A A A What's in ... a new mom or a seasoned parenting pro, breastfeeding often comes with its fair share of questions. ...

  13. Micromachined peristaltic pumps

    NASA Technical Reports Server (NTRS)

    Hartley, Frank T. (Inventor)

    1999-01-01

    Micromachined pumps including a channel formed between a first membrane and a substrate or between first and second flexible membranes. A series of electrically conductive strips is applied to a surface of the substrate or one of the membranes. Application of a sequential voltage to the series of strips causes a region of closure to progress down the channel to achieve a pumping action.

  14. Water Treatment Technology - Pumps.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on pumps provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pumps in plant and distribution systems, pump…

  15. Detection of pump degradation

    SciTech Connect

    Casada, D.

    1994-12-31

    There are a variety of stressors that can affect the operation of centrifugal pumps. Although these general stressors are active in essentially all centrifugal pumps, the stressor level and the extent of wear and degradation can vary greatly. Parameters that affect the extent of stressor activity are manifold. In order to assure the long-term operational readiness of a pump, it is important to both understand the nature and magnitude of the specific degradation mechanisms and to monitor the performance of the pump. The most commonly applied method of monitoring the condition of not only pumps, but rotating machinery in general, is vibration analysis. Periodic or continuous spectral vibration analysis is a cornerstone of most pump monitoring programs. In the nuclear industry, non-spectral vibration monitoring of safety-related pumps is performed in accordance with the ASME code. Although vibration analysis has dominated the condition monitoring field for many years, there are other measures that have been historically used to help understand pump condition: advances in historically applied technologies and developing technologies offer improved monitoring capabilities. The capabilities of several technologies (including vibration analysis, dynamic pressure analysis, and motor power analysis) to detect the presence and magnitude of both stressors and resultant degradation are discussed.

  16. Solar heat pump

    NASA Astrophysics Data System (ADS)

    Hermanson, R.

    Brief discussions of the major components of a solar powered, chemical ground source heat pump are presented. The components discussed are the solar collectors and the chemical heat storage battery. Sodium sulfide is the medium used for heat storage. Catalog information which provides a description of all of the heat pump systems is included.

  17. Water Treatment Technology - Pumps.

    ERIC Educational Resources Information Center

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on pumps provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: types of pumps in plant and distribution systems, pump…

  18. Estimating Pump Blockage

    NASA Technical Reports Server (NTRS)

    Chung, W.; Meng, S. Y.; Meng, C. Y.

    1984-01-01

    Blockage predicted for all components including inducers, impellers and diffusers. Pump performance predicted by semiempirical method shows excellent agreement with test results in Space Shuttle main-engine highpressure fuel turbopump. Comparisons of pump efficiency show equally good agreement of calculated values with experimental ones. Method improves current estimation methods based solely on subjective engineering judgment.

  19. A Shocking New Pump

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Hydro Dynamics, Inc. received a technical helping hand from NASA that made their Hydrosonic Pump (HPump) a reality. Marshall engineers resolved a bearing problem in the rotor of the pump and recommended new bearings, housings and mounting hardware as a solution. The resulting HPump is able to heat liquids with greater energy efficiency using shock waves to generate heat.

  20. NEUTRONIC REACTOR FUEL PUMP

    DOEpatents

    Cobb, W.G.

    1959-06-01

    A reactor fuel pump is described which offers long life, low susceptibility to radiation damage, and gaseous fission product removal. An inert-gas lubricated bearing supports a journal on one end of the drive shsft. The other end has an impeller and expansion chamber which effect pumping and gas- liquid separation. (T.R.H.)

  1. Advances in pump technology: insulin patch pumps, combined pumps and glucose sensors, and implanted pumps.

    PubMed

    Schaepelynck, P; Darmon, P; Molines, L; Jannot-Lamotte, M F; Treglia, C; Raccah, D

    2011-12-01

    This review discusses the most recent developments in insulin pump technology. The benefits of the insulin pump to patients with type 1 diabetes are recognized both for its metabolic effectiveness and its positive effects on quality of life. The current pumps are reliable, small and light, and are becoming more and more sophisticated. Nevertheless, there remain practical and psychological constraints for the patient. However, recent patch-pump advances should simplify the technical aspects of pump treatment and enhance patient comfort. Another advance combines the insulin pump with a glucose sensor. Such a combination is logical for optimizing pump use and, to that end, developing an automated or 'closed-loop'system that permits the delivery of subcutaneous insulin adjusted according to measured levels of subcutaneous glucose. Finally, implanted insulin pumps have proven their worth not only because of their simple use, but also for their contribution in the artificial pancreas project. Indeed, the prompt response with intraperitoneal administration of insulin makes it of interest for use in a closed-loop system.

  2. Normetex Pump Alternatives Study

    SciTech Connect

    Clark, Elliot A.

    2013-04-25

    A mainstay pump for tritium systems, the Normetex scroll pump, is currently unavailable because the Normetex company went out of business. This pump was an all-metal scroll pump that served tritium processing facilities very well. Current tritium system operators are evaluating replacement pumps for the Normetex pump and for general used in tritium service. An all-metal equivalent alternative to the Normetex pump has not yet been identified. 1. The ideal replacement tritium pump would be hermetically sealed and contain no polymer components or oils. Polymers and oils degrade over time when they contact ionizing radiation. 2. Halogenated polymers (containing fluorine, chlorine, or both) and oils are commonly found in pumps. These materials have many properties that surpass those of hydrocarbon-based polymers and oils, including thermal stability (higher operating temperature) and better chemical resistance. Unfortunately, they are less resistant to degradation from ionizing radiation than hydrocarbon-based materials (in general). 3. Polymers and oils can form gaseous, condensable (HF, TF), liquid, and solid species when exposed to ionizing radiation. For example, halogenated polymers form HF and HCl, which are extremely corrosive upon reaction with water. If a pump containing polymers or oils must be used in a tritium system, the system must be designed to be able to process the unwanted by-products. Design features to mitigate degradation products include filters and chemical or physical traps (eg. cold traps, oil traps). 4. Polymer components can work in tritium systems, but must be replaced regularly. Polymer components performance should be monitored or be regularly tested, and regular replacement of components should be viewed as an expected normal event. A radioactive waste stream must be established to dispose of used polymer components and oil with an approved disposal plan developed based on the facility location and its regulators. Polymers have varying

  3. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    SciTech Connect

    Sponseller, D.L.; Bakker, W.T.; Timmons, G.A.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method. The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded to 84-mm OD x 64-mm ID tubes, and to 51-mm OD x 38-mm ID tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to be base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3% of the bond-line length. Cost estimates for commercial production of 51-mm tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes). Such tubes should be attractive for the following applications in utility boilers: high-corrosion areas of existing coal-fired boilers, in both steam-generating tubes and superheaters; water walls, screen tubes, and superheater tubes of municipal waste-incineration boilers; future ultra super-critical boilers operating a higher temperatures and pressures; and steam-generating tubes of Syngas coolers of integrated coal gasification power plants.

  4. Corrosion Resistant Cladding by YAG Laser Welding in Underwater Environment

    SciTech Connect

    Tsutomi Kochi; Toshio Kojima; Suemi Hirata; Ichiro Morita; Katsura Ohwaki

    2002-07-01

    It is known that stress-corrosion cracking (SCC) will occur in nickel-base alloys used in Reactor Pressure Vessel (RPV) and Internals of nuclear power plants. A SCC sensitivity has been evaluated by IHI in each part of RPV and Internals. There are several water level instrumentation nozzles installed in domestic BWR RPV. In water level instrumentation nozzles, 182 type nickel-base alloys were used for the welding joint to RPV. It is estimated the SCC potential is high in this joint because of a higher residual stress than the yield strength (about 400 MPa). This report will describe a preventive maintenance method to these nozzles Heat Affected Zone (HAZ) and welds by a corrosion resistant cladding (CRC) by YAG Laser in underwater environment (without draining a reactor water). There are many kinds of countermeasures for SCC, for example, Induction Heating Stress Improvement (IHSI), Mechanical Stress Improvement Process (MSIP) and so on. A YAG laser CRC is one of them. In this technology a laser beam is used for heat source and irradiated through an optical fiber to a base metal and SCC resistant material is used for welding wires. After cladding the HAZ and welds are coated by the corrosion resistant materials so their surfaces are improved. A CRC by gas tungsten arc welding (GTAW) in an air environment had been developed and already applied to a couple of operating plants (16 Nozzles). This method was of course good but it spent much time to perform because of an installation of some water-proof working boxes to make a TIG-weldability environment. CRC by YAG laser welding in underwater environment has superior features comparing to this conventional TIG method as follows. At the viewpoint of underwater environment, (1) an outage term reduction (no drainage water). (2) a radioactive exposure dose reduction for personnel. At that of YAG laser welding, (1) A narrower HAZ. (2) A smaller distortion. (3) A few cladding layers. A YAG laser CRC test in underwater

  5. Widely tunable femtosecond solitonic radiation in photonic crystal fiber cladding

    SciTech Connect

    Peng Jiahui; Sokolov, Alexei V.; Benabid, F.; Light, P. S.; Couny, F.; Biancalana, F.; Roberts, P. J.

    2010-03-15

    We report on a means to generate tunable ultrashort optical pulses. We demonstrate that dispersive waves generated by solitons within the small-core features of a photonic crystal fiber cladding can be used to obtain femtosecond pulses tunable over an octave-wide spectral range. The generation process is highly efficient and occurs at the relatively low laser powers available from a simple Ti:sapphire laser oscillator. The described phenomenon is general and will play an important role in other systems where solitons are known to exist.

  6. Deep well solar pump

    SciTech Connect

    Vanek, J.

    1990-02-06

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

  7. Centrifugal pump fuel system

    SciTech Connect

    McGlone, M.E.; Larkins, L.J.; Johnson, R.O.; Moeller, K.A.

    1993-06-22

    A centrifugal pump fuel system for an engine driven fuel pump for an aircraft gas turbine engine is described comprising: a centrifugal pump having at constant speed rising head/flow characteristic at low flows; a plumbing system receiving flow from the pump, and having at least one control valve located down stream of and defining a discrete volume of the plumbing system; a plumbing resonant frequency defined by the discrete volume, the geometry of the plumbing system, and the bulk modulus of the fuel; a pressure difference regulating valve located adjacent to the discharge of the pump, up stream of the vast majority of the discrete volume; and the frequency response of the regulating valve being significantly less than the frequency response of the plumbing system such that the response of the regulating valve is attenuated at the resonant frequency of the plumbing system.

  8. Rotary Blood Pump

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George A. (Inventor); Bacak, James W. (Inventor); Svejkovsky, Paul A. (Inventor); Benkowski, Robert J. (Inventor)

    1996-01-01

    A rotary blood pump includes a pump housing for receiving a flow straightener, a rotor mounted on rotor bearings and having an inducer portion and an impeller portion, and a diffuser. The entrance angle, outlet angle, axial and radial clearances of blades associated with the flow straightener, inducer portion, impeller portion and diffuser are optimized to minimize hemolysis while maintaining pump efficiency. The rotor bearing includes a bearing chamber that is filled with cross-linked blood or other bio-compatible material. A back emf integrated circuit regulates rotor operation and a microcomputer may be used to control one or more back emf integrated circuits. A plurality of magnets are disposed in each of a plurality of impeller blades with a small air gap. A stator may be axially adjusted on the pump housing to absorb bearing load and maximize pump efficiency.

  9. A Valveless Pump

    NASA Astrophysics Data System (ADS)

    Bringley, Thomas; Childress, Stephen; Vandenberghe, Nicolas

    2004-11-01

    We study experimentally a simple valveless mechanical pump. The pumping mechanism could help to explain the successful circulation of blood in the cardiovascular systems of the human fetus, certain organisms whose hearts have no valves, and a person undergoing CPR. Because of its simplicity, the pump may also have applications in microfluidics. The experimental setup consists of two connected sections of tube, one rigid and one elastic, filled with water. To pump, a segment of the elastic section is pressed closed periodically. We examine the effects of varying the location of the forced segment and the forcing frequency. Both the magnitude and the direction of the pumping are observed to depend on both parameters. Moreover, certain frequencies result in destructive interference or resonance. We present some simple numerical models to try to explain these observations.

  10. High pressure liquid gas pump

    NASA Technical Reports Server (NTRS)

    Acres, R. L.

    1972-01-01

    Design and development of two types of pumps for handling liquefied gases are discussed. One pump uses mechanical valve shift and other uses pneumatic valve shift. Illustrations of pumps are provided and detailed description of operation is included.

  11. 78 FR 9676 - Clad Steel Plate From Japan: Continuation of Antidumping Duty Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... International Trade Administration Clad Steel Plate From Japan: Continuation of Antidumping Duty Order AGENCY... Japan would likely lead to a continuation or recurrence of dumping and material injury to an industry in... sunset review of the antidumping duty order on clad steel plate from Japan pursuant to section 751(c) of...

  12. Assessment of wear coefficients of nuclear zirconium claddings without and with pre-oxidation

    DOE PAGES

    Qu, Jun; Cooley, Kevin M.; Shaw, Austin H.; ...

    2016-03-16

    In the cores of pressurized water nuclear reactors, water-flow induced vibration is known to cause claddings on the fuel rods to rub against their supporting grids. Such grid-to-rod-fretting (GTRF) may lead to fretting wear-through and the leakage of radioactive species. The surfaces of actual zirconium alloy claddings in a reactor are inevitably oxidized in the high-temperature pressurized water, and some claddings are even pre-oxidized. As a result, the wear process of the surface oxide film is expected to be quite different from the zirconium alloy substrate. In this paper, we attempt to measure the wear coefficients of zirconium claddings withoutmore » and with pre-oxidation rubbing against grid samples using a bench-scale fretting tribometer. Results suggest that the volumetric wear coefficient of the pre-oxidized cladding is 50 to 200 times lower than that of the untreated cladding. In terms of the linear rate of wear depth, the pre-oxidized alloy wears about 15 times more slowly than the untreated cladding. Finally, fitted with the experimentally-determined wear rates, a stage-wise GTRF engineering wear model demonstrates good agreement with in-reactor experience in predicting the trend of cladding lives.« less

  13. Cladding modes in photonic crystal fiber: characteristics and sensitivity to surrounding refractive index

    NASA Astrophysics Data System (ADS)

    Jiang, Xiuli; Gu, Zhengtian; Zheng, Li

    2016-01-01

    Characteristics of cladding modes in a photonic crystal fiber (PCF) with triangular air-hole lattice in the cladding are numerically analyzed using a finite element method. The transition for LP11 cladding mode to core mode with variation of the normalized wavelength has been shown. The transition of the LP01 cladding mode to the outer silica mode and reorganization of the LP0m cladding modes caused by varying the fiber radius has been investigated. By choosing the optimized fiber radius, which is located in the cladding modes' reorganization region, the sensitivity of the coupled wavelength between the core mode LP01 and cladding mode LP03 to surrounding refractive index is increased by a factor of five and reaches to 2660 nm/refractive index unit over the range of 1.40 to 1.42. The sensitivity is competitive with that of long-period grating in PCF in response to changes in refractive indices of the medium contained in the cladding air channels.

  14. Hydrogen permeation in FeCrAl alloys for LWR cladding application

    SciTech Connect

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; Snead, Lance L.

    2015-03-19

    FeCrAl is an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through FeCrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In our study, the hydrogen permeability of several FeCrAl alloys was obtained using a static permeation test station, which was calibrated and validated using 304 stainless steel. The high hydrogen permeability of FeCrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. Also, the total tritium inventory inside the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion model to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from FeCrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using FeCrAl clad fuel assemblies.

  15. An Examination of Collaborative Learning Assessment through Dialogue (CLAD) in Traditional and Hybrid Human Development Courses

    ERIC Educational Resources Information Center

    McCarthy, Wanda C.; Green, Peter J.; Fitch, Trey

    2010-01-01

    This investigation assessed the effectiveness of using Collaborative Learning Assessment through Dialogue (CLAD) (Fitch & Hulgin, 2007) with students in undergraduate human development courses. The key parts of CLAD are student collaboration, active learning, and altering the role of the instructor to a guide who enhances learning opportunities.…

  16. Hydrogen permeation in FeCrAl alloys for LWR cladding application

    DOE PAGES

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; ...

    2015-03-19

    FeCrAl is an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through FeCrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In our study, the hydrogen permeability of several FeCrAl alloys was obtained using a static permeation test station, which was calibrated and validated using 304 stainless steel. The high hydrogen permeability of FeCrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. Also, the total tritium inventory insidemore » the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion model to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from FeCrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using FeCrAl clad fuel assemblies.« less

  17. Influence of additions of nanoparticles TaC on a microstructure laser cladding

    NASA Astrophysics Data System (ADS)

    Murzakov, M. A.; Petrovskiy, V. N.; Polski, V. I.; Mironov, V. D.; Prokopova, N. M.; Tret'yakov, E. V.

    2015-03-01

    The features of a laser cladding of nickel-based powders with TaC nanopowder additives have been experimentally investigated. The minimum depth of pro-melting of a basis, microhardness distribution over the cross section of the substrate, and the saturation of the metal of the cladding with basis components has been determined in the experiments.

  18. Conical reflection of light during free-space coupling into a symmetrical metal-cladding waveguide.

    PubMed

    Zheng, Yuanlin; Cao, Zhuangqi; Chen, Xianfeng

    2013-09-01

    Novel conical reflection of light by a thick three-layered metal-clad optical waveguide is observed. A symmetrical metal-cladding optical waveguide is used, which exhibits extraordinary conical reflection during free-space coupling of light to the waveguide. The phenomenon is attributed to the leakage of excited ultrahigh-order guided modes and their inter- and intramode coupling interaction.

  19. Hydrogen permeation in FeCrAl alloys for LWR cladding application

    NASA Astrophysics Data System (ADS)

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.; Snead, Lance L.

    2015-06-01

    FeCrAl, an advanced oxidation-resistant iron-based alloy class, is a highly prevalent candidate as an accident-tolerant fuel cladding material. Compared with traditional zirconium alloy fuel cladding, increased tritium permeation through FeCrAl fuel cladding to the primary coolant is expected, raising potential safety concerns. In this study, the hydrogen permeability of several FeCrAl alloys was obtained using a static permeation test station, which was calibrated and validated using 304 stainless steel. The high hydrogen permeability of FeCrAl alloys leads to concerns with respect to potentially significant tritium release when used for fuel cladding in LWRs. The total tritium inventory inside the primary coolant of a light water reactor was quantified by applying a 1-dimensional steady state tritium diffusion model to demonstrate the dependence of tritium inventory on fuel cladding type. Furthermore, potential mitigation strategies for tritium release from FeCrAl fuel cladding were discussed and indicate the potential for application of an alumina layer on the inner clad surface to serve as a tritium barrier. More effort is required to develop a robust, economical mitigation strategy for tritium permeation in reactors using FeCrAl clad fuel assemblies.

  20. Optimization of Peak Type Metal Clad Waveguide Sensor Using Different Metals

    NASA Astrophysics Data System (ADS)

    Kumar, Ajesh; Pal, Sarika

    2017-08-01

    The comprehensive analysis for the prism coupled peak type metal clad waveguide sensor in reflection mode has been done for different metals. The proposed four layer structure contains very thin cladding of metal layer deposited on the substrate for the peak type operation. The proposed sensor has been analyzed in TE mode.