Science.gov

Sample records for cryogenic ge performance

  1. Cryogenic ultra-low-noise SiGe transistor amplifier.

    PubMed

    Ivanov, B I; Trgala, M; Grajcar, M; Il'ichev, E; Meyer, H-G

    2011-10-01

    An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz-100 MHz. A noise temperature T(N) ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ~50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/√Hz. The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.

  2. Performance of Power Converters at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Elbuluk, Malik E.; Gerber, Scott; Hammoud, Ahmad; Patterson, Richard L.

    2001-01-01

    Power converters capable of operation at cryogenic temperatures are anticipated to play an important role in the power system architecture of future NASA deep space missions. Design of such converters to survive cryogenic temperatures will improve the power system performance and reduce development and launch costs. Aerospace power systems are mainly a DC distribution network. Therefore, DC/DC and DC/AC converters provide the outputs needed to different loads at various power levels. Recently, research efforts have been performed at the NASA Glenn Research Center (GRC) to design and evaluate DC/DC converters that are capable of operating at cryogenic temperatures. This paper presents a summary of the research performed to evaluate the low temperature performance of five DC/DC converters. Various parameters were investigated as a function of temperature in the range of 20 to -196 C. Data pertaining to the output voltage regulation and efficiency of the converters is presented and discussed.

  3. IRAS cryogenic system flight performance report

    NASA Technical Reports Server (NTRS)

    Urbach, A. R.; Mason, P. V.

    1984-01-01

    It is pointed out that the Infrared Astronomical Satellite (IRAS) is the first telescope to perform observations in the far infrared from orbit. IRAS was launched on January 25, 1983 into a 900 km orbit. The use of the first large superfluid helium dewar in space makes it possible to provide a 2 K telescope environment for an anticipated period of one year. A description of the cryogenic system of IRAS is presented, taking into account the superfluid helium tank, the insulation system, the vacuum shell, the aperture cover, and the fluid management system. The dynamic performance of the cryogenic system is considered along with aspects of prelaunch preparations. Details of flight performance are also discussed, giving attention to transient performance, and steady state performance.

  4. Realization and performance of cryogenic selection mechanisms

    NASA Astrophysics Data System (ADS)

    Aitink-Kroes, Gabby; Bettonvil, Felix; Kragt, Jan; Elswijk, Eddy; Tromp, Niels

    2014-07-01

    Within Infra-Red large wavelength bandwidth instruments the use of mechanisms for selection of observation modes, filters, dispersing elements, pinholes or slits is inevitable. The cryogenic operating environment poses several challenges to these cryogenic mechanisms; like differential thermal shrinkage, physical property change of materials, limited use of lubrication, high feature density, limited space etc. MATISSE the mid-infrared interferometric spectrograph and imager for ESO's VLT interferometer (VLTI) at Paranal in Chile coherently combines the light from 4 telescopes. Within the Cold Optics Bench (COB) of MATISSE two concepts of selection mechanisms can be distinguished based on the same design principles: linear selection mechanisms (sliders) and rotating selection mechanisms (wheels).Both sliders and wheels are used at a temperature of 38 Kelvin. The selection mechanisms have to provide high accuracy and repeatability. The sliders/wheels have integrated tracks that run on small, accurately located, spring loaded precision bearings. Special indents are used for selection of the slider/wheel position. For maximum accuracy/repeatability the guiding/selection system is separated from the actuation in this case a cryogenic actuator inside the cryostat. The paper discusses the detailed design of the mechanisms and the final realization for the MATISSE COB. Limited lifetime and performance tests determine accuracy, warm and cold and the reliability/wear during life of the instrument. The test results and further improvements to the mechanisms are discussed.

  5. Thermal Performance Testing Of Cryogenic Piping Systems

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Augustynowicz, S. D.; Nagy, Z. F.

    2003-01-01

    Thermal performance measurement of piping systems under actual field conditions is important for space launch development and commercial industry. Knowledge of the true insulating effectiveness is needed in system design, development, and research activities. A new 18-meter-long test apparatus for cryogenic pipelines has been developed. Three different pipelines, rigid or flexible, can be tested simultaneously. Critical factors in heat leak measurements include eliminating heat transfer at end connections and obtaining proper liquid saturation condition. Effects due to variations in the external ambient conditions like wind, humidity, and solar radiation must be minimized. The static method of liquid nitrogen evaporation has been demonstrated, but the apparatus can be adapted for dynamic testing with cryogens, chilled water, or other working fluids. This technology is suited for the development of an industry standard test apparatus and method. Examples of the heat transfer data from testing commercially available pipelines are given. Prototype pipelines are currently being tested and evaluated at the Cryogenics Test Laboratory of NASA Kennedy Space Center.

  6. Thermal Performance Testing of Cryogenic Insulation Systems

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.; Augustynowicz, Stan D.; Scholtens, Brekke E.

    2007-01-01

    Efficient methods for characterizing thermal performance of materials under cryogenic and vacuum conditions have been developed. These methods provide thermal conductivity data on materials under actual-use conditions and are complementary to established methods. The actual-use environment of full temperature difference in combination with vacuum-pressure is essential for understanding insulation system performance. Test articles include solids, foams, powders, layered blankets, composite panels, and other materials. Test methodology and apparatus design for several insulation test cryostats are discussed. The measurement principle is liquid nitrogen boil-off calorimetry. Heat flux capability ranges from approximately 0.5 to 500 watts per square meter; corresponding apparent thermal conductivity values range from below 0.01 up to about 60 mW/m- K. Example data for different insulation materials are also presented. Upon further standardization work, these patented insulation test cryostats can be available to industry for a wide range of practical applications.

  7. Gates for electron confinement in Si/SiGe 2DEGs at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Slinker, K. A.; Klein, L. J.; Goswami, S.; Truitt, J. L.; Savage, D. E.; Lagally, M. G.; van der Weide, D. W.; Coppersmith, S. N.; Eriksson, M. A.; Chu, J. O.; Ott, J. A.; Mooney, P. M.

    2004-03-01

    A major challenge is the fabrication of ultra-low leakage gates for 2DEG confinement in Si/SiGe at cryogenic temperatures. Here we report results on the fabrication of gates by four different methods: metallic Schottky gates, metal-oxide-silicon, metal-dielectric-silicon using spin-on glass, and lateral etch-defined gates. Lateral etch-defined gates are shown to produce quantum dots displaying Coulomb blockade. We discuss the prospects for producing similar structures using truly metallic gates in combination with etch-defined trenches.

  8. Cryogenic performance of the space infrared optical payload

    NASA Astrophysics Data System (ADS)

    Wang, Dawei; Tan, Fanjiao; Zhang, Wei; Liu, Mingdong; Wang, Haipeng

    2016-10-01

    A model as well as the methodology is proposed to analyze the cryogenic performance of space infrared optical payload. And the model is established from two aspects: imaging quality and background radiation. On the basis of finite element analysis, the deformation of optical surface in cryogenic environment is characterized by Zernike polynomials, and then, the varying pattern of MTF of space cryogenic optical payload could be concluded accordingly. Then from the theory of thermal radiative transfer, the temperature distribution and the deformation of the optical payload under the action of inertial load and thermal load are analyzed based on the finite element method, and the spontaneous radiation and scattering properties of the optical surface and shielding factors between the opto-mechanical structure are considered to establish the radiation calculation model. Furthermore, the cryogenic radiation characteristics of the space infrared optical payload are obtained by the radiation calculation model. Finally, experiments are conducted using an actual off-axis TMA space infrared optical payload. And the results indicate that the background radiation of the space infrared optical payload is decreased by 79% while 33% for MTF at the thermal control temperature of 240K. In this circumstance, the system background radiation is effectively suppressed and the detection sensitivity of the optical payload is improved as well, while the imaging quality is acceptable. The model proposed in this paper can be applied to the analyzing cryogenic properties of space infrared optical payload, and providing theoretical guidance for the design and application of the space cryogenic optical payload.

  9. Cryogenic performance of high-efficiency germanium immersion grating

    NASA Astrophysics Data System (ADS)

    Sarugaku, Yuki; Ikeda, Yuji; Kaji, Sayumi; Kobayashi, Naoto; Sukegawa, Takashi; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

    2016-08-01

    Immersion gratings will play important roles for infrared astronomy in the next generation. We have been developing immersion gratings with a variety of kinds of materials and have succeeded in fabricating a high-efficiency germanium (Ge) immersion grating with both a reflection coating on the grating surface and an AR coating on the entrance surface. The grating will be installed in a K-, L-, and M-bands (2-5μm) high-resolution (R=80,000) spectrograph, VINROUGE, which is a prototype for the TMT MIR instrument. In this paper, we report the preliminary results on the evaluation of the Ge immersion grating. We confirmed that the peak absolute diffraction efficiency was in the range of 70-80%, which was as expected from the design, at both room and cryogenic temperatures.

  10. Initial performance of upgraded Tevatron cryogenic systems

    SciTech Connect

    Norris, B.L.

    1996-09-01

    Fermilab began operating a re-designed satellite refrigerator systems in November 1993. Upgrades were installed to operate the Tevatron at a magnet temperature of 3.5 K, approximately 1K lower than the original design. Refrigerator upgrades included new valve boxes, larger reciprocating expanders, the installation of cold vapor compressors, new sub-atmospheric instrumentation and an entirely new distributed controls system. Cryogenic system reliability data for Colliding Physics Run 1B is presented emphasizing a failure analysis for each aspect of the upgrade. Comparison to data for Colliding Physics Run 1A (previous to upgrade) is presented to show the impact of a major system overhaul. New operational problems and their solutions are presented in detail.

  11. TankSIM: A Cryogenic Tank Performance Prediction Program

    NASA Technical Reports Server (NTRS)

    Bolshinskiy, L. G.; Hedayat, A.; Hastings, L. J.; Moder, J. P.; Schnell, A. R.; Sutherlin, S. G.

    2015-01-01

    Accurate prediction of the thermodynamic state of the cryogenic propellants in launch vehicle tanks is necessary for mission planning and successful execution. Cryogenic propellant storage and transfer in space environments requires that tank pressure be controlled. The pressure rise rate is determined by the complex interaction of external heat leak, fluid temperature stratification, and interfacial heat and mass transfer. If the required storage duration of a space mission is longer than the period in which the tank pressure reaches its allowable maximum, an appropriate pressure control method must be applied. Therefore, predictions of the pressurization rate and performance of pressure control techniques in cryogenic tanks are required for development of cryogenic fluid long-duration storage technology and planning of future space exploration missions. This paper describes an analytical tool, Tank System Integrated Model (TankSIM), which can be used for modeling pressure control and predicting the behavior of cryogenic propellant for long-term storage for future space missions. It is written in the FORTRAN 90 language and can be compiled with any Visual FORTRAN compiler. A thermodynamic vent system (TVS) is used to achieve tank pressure control. Utilizing TankSIM, the following processes can be modeled: tank self-pressurization, boiloff, ullage venting, and mixing. Details of the TankSIM program and comparisons of its predictions with test data for liquid hydrogen and liquid methane will be presented in the final paper.

  12. A high-performance wave guide cryogenic thermal break.

    PubMed

    Melhuish, S J; McCulloch, M A; Piccirillo, L; Stott, C

    2016-10-01

    We describe a high-performance wave guide cryogenic thermal break. This has been constructed both for Ka band, using WR28 wave guide, and Q band, using WR22 wave guide. The mechanical structure consists of a hexapod (Stewart platform) made from pultruded carbon fibre tubing. We present a tentative examination of the cryogenic Young's modulus of this material. The thermal conductivity is measured at temperatures above the range explored by Runyan and Jones, resulting in predicted conductive loads through our thermal breaks of 3.7 mW to 3 K and 17 μK to 1 K.

  13. A high-performance wave guide cryogenic thermal break

    NASA Astrophysics Data System (ADS)

    Melhuish, S. J.; McCulloch, M. A.; Piccirillo, L.; Stott, C.

    2016-10-01

    We describe a high-performance wave guide cryogenic thermal break. This has been constructed both for Ka band, using WR28 wave guide, and Q band, using WR22 wave guide. The mechanical structure consists of a hexapod (Stewart platform) made from pultruded carbon fibre tubing. We present a tentative examination of the cryogenic Young's modulus of this material. The thermal conductivity is measured at temperatures above the range explored by Runyan and Jones, resulting in predicted conductive loads through our thermal breaks of 3.7 mW to 3 K and 17 μK to 1 K.

  14. Performance of the new cryogenic vacuum system at the Bevatron

    SciTech Connect

    Avery, R.T.; Alonso, J.R.; Henderson, T.F.; Kennedy, K.D.; Meneghetti, J.R.

    1983-08-01

    A cryogenically cooled liner has been installed within the Bevatron to achieve 10/sup -10/ Torr vacuum. Features and performance of this liner are described including achieved pressures, residual gas composition, cryo heat loads, leak rates through moving and static seals, and cool-down and warm-up times.

  15. Performance of the new cryogenic vacuum system at the Bevatron

    SciTech Connect

    Avery, R.T.; Henderson, T.F.; Kennedy, K.D.; Meneghetti, J.R.; Alonso, J.R.

    1983-03-01

    A cryogenically cooled liner has been installed within the Bevatron to achieve 10/sup -10/ torr vacuum. Features and performance of this liner are described including achieved pressures, residual gas composition, cryo heat loads, leak rates through moving and static seals, and cool-down and warm-up times.

  16. Standardization in Cryogenic Insulation Systems Testing and Performance Data

    NASA Astrophysics Data System (ADS)

    Fesmire, James E.

    The close relationship between industrial energy use and cryogenics drives the need for optimized thermal insulation systems. Emerging cryofuels usage is enabled by adequate isolation of the liquid hydrogen or liquefied natural gas from the ambient environment. Thermal performance data for the total insulation system, as rendered, are essential for both engineering designs and cost-benefit decisions involving comparisons among alternatives. These data are obtained through rigorous testing with suitable apparatus and repeatable methods. Properly defined terminology, analysis, and reporting are also vital. Advances in cryogenic insulation test apparatus and methods have led to the recent addition of two new technical standards of ASTM International: C1774 - Standard Guide for Thermal Performance Testing of Cryogenic InsulationSystems and C740 - Standard Guide for Evacuated Reflective Cryogenic Insulation. Among the different techniques described in the new standards is the cylindrical boiloff calorimeter for absolute heat measurement over the full range of vacuum pressure conditions. The details of this apparatus, test method, and data analysis are given. Benchmark thermal performance data, including effective thermal conductivity (ke) and heat flux (q) for the boundary temperatures of 293 K and 77 K, are given for a number of different multilayer insulation (MLI) systems in comparison with data for other commonly-used insulation systems including perlite powder, fiberglass, polyurethane foam, and aerogels.

  17. Performance and Reliability of Solid Tantalum Capacitors at Cryogenic Conditions

    NASA Technical Reports Server (NTRS)

    Teverovsky, Alexander

    2006-01-01

    Performance of different types of solid tantalum capacitors was evaluated at room and low temperatures, down to 15 K. The effect of temperature on frequency dependencies of capacitance, effective series resistances (ESR), leakage currents, and breakdown voltages has been investigated and analyzed. To assess thermo-mechanical robustness of the parts, several groups of loose capacitors and those soldered on FR4 boards were subjected to multiple (up to 500) temperature cycles between room temperature and 77 K. Experiments and mathematical modeling have shown that degradation in tantalum capacitors at low temperatures is mostly due to increasing resistance of the manganese cathode layer, resulting in substantial decrease of the roll-off frequency. Absorption currents follow a power law, I approximately t(sup -m), with the exponent m varying from 0.8 to 1.1. These currents do not change significantly at cryogenic conditions and the value of the exponent remains the same down to 15 K. Variations of leakage currents with voltage can be described by Pool-Frenkel and Schottky mechanisms of conductivity, with the Schottky mechanism prevailing at cryogenic conditions. Breakdown voltages of tantalum capacitors increase and the probability of scintillations decreases at cryogenic temperatures. However, breakdown voltages measured during surge current testing decrease at liquid nitrogen (LN) compared to room-temperature conditions. Results of temperature cycling suggest that tantalum capacitors are capable of withstanding multiple exposures to cryogenic conditions, but the probability of failures varies for different part types.

  18. Performance tests of a cryogenic hybrid magnetic bearing for turbopumps

    NASA Technical Reports Server (NTRS)

    Dirusso, Eliseo; Brown, Gerald V.

    1992-01-01

    Experiments were performed on a Hybrid Magnetic Bearing designed for cryogenic applications such as turbopumps. This bearing is considerably smaller and lighter than conventional magnetic bearings and is more efficient because it uses a permanent magnet to provide a bias flux. The tests were performed in a test rig that used liquid nitrogen to simulate cryogenic turbopump temperatures. The bearing was tested at room temperature and at liquid nitrogen temperature (-320 F). The maximum speed for the test rig was 14000 rpm. For a magnetic bearing stiffness of 20000 lb/in, the flexible rotor had two critical speeds. A static (nonrotating) bearing stiffness of 85000 lb/in was achieved. Magnetic bearing stiffness, permanent magnet stiffness, actuator gain, and actuator force interaction between two axes were evaluated, and controller/power amplifier characteristics were determined. The tests revealed that it is feasible to use this bearing in the cryogenic environment and to control the rotor dynamics of flexible rotors when passing through bending critical speeds. The tests also revealed that more effort should be placed on enhancing the controller to achieve higher bearing stiffness and on developing displacement sensors that reduce drift caused by temperature and reduce sensor electrical noise.

  19. Design and performance of a cryogenic iris aperture mechanism

    NASA Astrophysics Data System (ADS)

    de Jonge, C.; Laauwen, W. M.; de Vries, E. A.; Smit, H. P.; Detrain, A.; Eggens, M. J.; Ferrari, L.; Dieleman, P.

    2014-07-01

    A cryogenic iris mechanism is under development as part of the ground calibration source for the SAFARI instrument. The iris mechanism is a variable aperture used as an optical shutter to fine-tune and modulate the absolute power output of the calibration source. It has 4 stainless steel blades that create a near-circular aperture in every position. The operating temperature is 4.5 Kelvin to provide a negligible background to the SAFARI detectors, and `hot spots' above 9K should be prevented. Cryogenic testing proved that the iris works at 4K. It can be used in a broad range of cryogenic optical instruments where optical throughput needs to be controlled. Challenges in the design include the low cooling power available (5mW) and low friction at cryogenic temperatures. The actuator is an `arc-type' rotary voice-coil motor. The use of flexural pivots creates a mono-stable mechanism with a resonance frequency at 26Hz. Accurate and fast position control with disturbance rejection is managed by a PID servo loop using a hall-sensor as input. At 4 Kelvin, the frequency is limited to 4Hz to avoid excess dissipation and heating. In this paper, the design and performance of the iris are discussed. The design was optimized using a thermal, magnetic and mechanical model made with COMSOL Finite Element Analysis software. The dynamical and state-space modeling of the mechanism and the concept of the electrical control are presented. The performance of the iris show good agreement to the analytical and COMSOL modeling.

  20. Boron diffusion layer formation using Ge cryogenic implantation with low-temperature microwave annealing

    NASA Astrophysics Data System (ADS)

    Murakoshi, Atsushi; Harada, Tsubasa; Miyano, Kiyotaka; Harakawa, Hideaki; Aoyama, Tomonori; Yamashita, Hirofumi; Kohyama, Yusuke

    2016-04-01

    It is shown that a low-sheet-resistance p-type diffusion layer with a small diffusion depth can be fabricated efficiently by cryogenic boron and germanium implantation combined with low-temperature (400 °C) microwave annealing. Compared with the conventional annealing at 1000 °C, a much smaller diffusion depth is obtained at the same sheet resistance. The low sheet resistance at 400 °C is due to microwave absorption in the surface amorphous layer, which is formed by cryogenic germanium implantation. However, the pn junction leakage was worse than that in conventional annealing, because crystal defects remain near the amorphous/crystal interface after microwave annealing. It is found that the pn junction leakage is improved greatly by cryogenic germanium implantation. These results show that a suitable combination of cryogenic implantation and microwave annealing is very promising for p-type diffusion layer technology.

  1. Design theory and performance of cryogenic molecular adsorption refrigeration systems

    NASA Technical Reports Server (NTRS)

    Hartwig, W. H.; Woltman, A. W.; Masson, J. P.

    1978-01-01

    Closed-cycle operation of molecular adsorption refrigeration systems (MARS) has been demonstrated by using thermally cycled zeolites to adsorb and desorb various gases under pressures of 20-60 atm. This paper develops three aspects of the design theory: the physical theory of molecular adsorption of small molecules such as A, N2, N2O and NH3, the design relations for closed-cycle flow for three or more compressors, and the coefficient of performance. This work is intended to demonstrate nonmechanical gas compression for various cryogenic gases than can compete with mechanical systems with a different mix of advantages and disadvantages.

  2. Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley Louis

    2010-01-01

    Multilayer insulation (MLI) has been shown to be the best performing cryogenic insulation system at high vacuum (less that 10 (exp 3) torr), and is widely used on spaceflight vehicles. Over the past 50 years, many investigations into MLI have yielded a general understanding of the many variables that are associated with MLI. MLI has been shown to be a function of variables such as warm boundary temperature, the number of reflector layers, and the spacer material in between reflectors, the interstitial gas pressure and the interstitial gas. Since the conduction between reflectors increases with the thickness of the spacer material, yet the radiation heat transfer is inversely proportional to the number of layers, it stands to reason that the thermal performance of MLI is a function of the number of layers per thickness, or layer density. Empirical equations that were derived based on some of the early tests showed that the conduction term was proportional to the layer density to a power. This power depended on the material combination and was determined by empirical test data. Many authors have graphically shown such optimal layer density, but none have provided any data at such low densities, or any method of determining this density. Keller, Cunnington, and Glassford showed MLI thermal performance as a function of layer density of high layer densities, but they didn't show a minimal layer density or any data below the supposed optimal layer density. However, it was recently discovered that by manipulating the derived empirical equations and taking a derivative with respect to layer density yields a solution for on optimal layer density. Various manufacturers have begun manufacturing MLI at densities below the optimal density. They began this based on the theory that increasing the distance between layers lowered the conductive heat transfer and they had no limitations on volume. By modifying the circumference of these blankets, the layer density can easily be

  3. The XRS Low Temperature Cryogenic System: Ground Performance Test Results

    NASA Technical Reports Server (NTRS)

    Breon, Susan; Sirron, Peter; Boyle, Robert; Canavan, Ed; DiPirro, Michael; Serlemitsos, Aristides; Tuttle, James; Whitehouse, Paul

    1998-01-01

    The X-Ray Spectrometer (XRS) instrument is part of the Astro-E mission scheduled to launch early in 2000. Its cryogenic system is required to cool a 32-element square array of x-ray microcalorimeters to 60-65 mK over a mission lifetime of at least 2 years. This is accomplished using an adiabatic demagnetization refrigerator (ADR) contained within a two-stage superfluid helium/solid neon cooler. Goddard Space Flight Center is providing the ADR and helium dewar. The flight system was assembled in Sept. 1997 and subjected to extensive thermal performance tests. This paper presents test results at both the system and component levels. In addition, results of the low temperature topoff performed in Japan with the engineering unit neon and helium dewars are discussed.

  4. Performance and Cost Evaluation of Cryogenic Solid Propulsion Systems

    NASA Astrophysics Data System (ADS)

    Adirim, Harry; Lo, Roger; Knecht, Thomas; Reinbold, Georg-Friedrich; Poller, Sascha

    2002-01-01

    Under the sponsorship of the German Aerospace Center DLR, Cryogenic Solid Propulsion (CSP) is now in its 6th year of R&D. The development proceeds as a joint international university-, small business-, space industry- and professional research effort (Berlin University of Technology / AI: Aerospace Institute, Berlin / Bauman Moscow State Technical University, Russia / ASTRIUM GmbH, Bremen / Fraunhofer Institute for Chemical Technology, Berghausen). This paper aims at introducing CSP as a novel type of chemical propellant that uses frozen liquids as Oxygen (SOX) or Hydrogen Peroxide (SH2O2) inside of a coherent solid Hydrocarbon (PE, PU or HTPB) matrix in solid rocket motors. Theoretically any conceivable chemical rocket propellant combination (including any environmentally benign ,,green propellant") can be used in solid rocket propellant motors if the definition of solids is not restricted to "solid at ambient temperature". The CSP concept includes all suitable high energy propellant combinations, but is not limited to them. Any liquid or hybrid bipropellant combination is (Isp-wise) superior to any conventional solid propellant formulation. While CSPs do share some of the disadvantages of solid propulsion (e.g. lack of cooling fluid and preset thrust-time function), they definitely share one of their most attractive advantages: the low number of components that is the base for high reliability and low cost of structures. In this respect, CSPs are superior to liquid propellant rocket motors with whom, they share the high Isp performance. High performance, low cost, low pollution CSP technology could bring about a near term improvement for chemical Earth-to-orbit high thrust propulsion. In the long run it could surpass conventional chemical propulsion because it is better suited for applying High Energy Density Matter (HEDM) than any other mode of propulsion. So far, ongoing preliminary analyses have not shown any insuperable problems in areas of concern, such as

  5. Influence of temperature on transit times and microwave noise performances of SiGe HBT

    NASA Astrophysics Data System (ADS)

    Diaz-Albarran, L. M.; Ramirez-Garcia, E.; Zerounian, N.; Aniel, F.; Rodriguez-Mendez, L. M.; Valdez-Perez, D.; Galaz-Larios, M. C.; Enciso-Aguilar, M. A.

    2016-03-01

    The influence of temperature (300 K and 40 K) on intrinsic transit times and microwave noise performances of silicon germanium (SiGe) heterojunction bipolar transistors (HBTs) is investigated. At 300 K, we compared measured and modelled S-parameters and four noise parameters, and we found a good agreement. At 40 K, we compared measured and modelled S-parameters, and we deduced noise performances from the S-parameter measurements. The electric model includes correlated junction noise sources and a proper extraction of the transit times involved in these sources. Moreover, the microwave noise model considers all the physical phenomena that impact noise performances in SiGe HBTs. We analysed three devices having different Ge content (10%-20%, 10%-25% and 10%-30%). At 40 K, the device with 10%-25% reaches one of the lowest base transit times (τ B), the lowest minimum noise figure (NFmin), and the lowest equivalent noise resistance (R n), for operation frequencies up to the maximum device dynamic performances (f ≈ f T) These results demonstrate the excellent potential to develop cryogenic applications of SiGe HBTs.

  6. Germanium JFET for Cryogenic Readout Electronics

    NASA Technical Reports Server (NTRS)

    Das, N. C.; Monroy, C.; Jhabvala, M.; Shu, P.

    1999-01-01

    The n-channel Germanium junction field effect transistor (Ge-JFET) was designed and fabricated for cryogenic applications. The Ge-JFET exhibits superior noise performance at liquid nitrogen temperature (77 K). From the device current voltage characteristics of n-channel JFETs, it is seen that transconductance increases monotonically with the lowering of temperature to 4.2 K (liquid helium temperature).

  7. Performance testing of a commercially produced cryogenic refrigerator

    SciTech Connect

    Keshock, E.G. . Dept. of Mechanical and Aerospace Engineering); Murphy, R.W. )

    1990-09-01

    A commercially available cryogenic refrigeration unit, model M-20, (3-phase, 60-Hz, 230-V) manufactured by Cryodynamics, Inc., was subjected to laboratory testing to measure some of its performance characteristics. Comparisons were made with those performance characteristics given in manufacturer literature for the M-20 unit (3-phase, 400-Hz, 208-V). At 77 K, the measured cooling capacity of the 60-Hz/230-V unit was very nearly the same (<2% difference) as the specified capacity (110 W) of the 400-Hz/208-V unit. At temperature levels higher than 77 K, measured cooling capacities exceeded the manufacturer product data sheet values. Coefficients of performance (COP) based on the experimental measurements ranged from about 0.37 at 250 K to 0.03 at 70 K. Comparison of measured to ideal (Carnot cycle) COPs yielded values ranging from about 8 to 18%, with broad maximum occurring between approximately 100 and 150 K. Finally, the measured cool-down time from room temperature to 77 K was about 10 minutes compared with a specification sheet value of 7.4 minutes. This difference may be attributed to lower thermal mass (without heater block) and higher operating frequency conditions associated with the specification. 6 figs., 2 tabs.

  8. Thermal Performance of a Cryogenic Fluid Management Cubesat Mission

    NASA Technical Reports Server (NTRS)

    Berg, J. J.; Oliveira, J. M.; Congiardo, J. F.; Walls, L. K.; Putman, P. T.; Haberbusch, M. S.

    2013-01-01

    Development for an in-space demonstration of a CubeS at as a Cryogenic Fluid Management (CFM) test bed is currently underway. The favorable economics of CubeSats make them appealing for technology development activity. While their size limits testing to smaller scales, many of the regimes relevant to CFM can still be achieved. The first demo flight of this concept, CryoCube®-1, will focus on oxygen liquefaction and low-gravity level sensing using Reduced Gravity CryoTracker®. An extensive thermal modeling effort has been underway to both demonstrate concept feasibility and drive the prototype design. The satellite will utilize both a sun- and earth-shield to passively cool its experimental tank below 115 K. An on-board gas generator will create high pressure gaseous oxygen, which will be throttled into a bottle in the experimental node and condensed. The resulting liquid will be used to perform various experiments related to level sensing. Modeling efforts have focused on the spacecraft thermal performance and its effects on condensation in the experimental node. Parametric analyses for both optimal and suboptimal conditions have been considered and are presented herein.

  9. Overview and Status of the 12 GeV Cryogenic System Upgrade At Jlab

    SciTech Connect

    Dana Arenius, Jonathan Creel, Venkatarao Ganni, Kelly Dixon, Peter Knudsen

    2010-04-01

    As part of the planned Jefferson Laboratory's electron accelerator (CEBAF) power upgrade, ten additional superconducting RF cryomodules will be added to its accelerator linacs. Although physically the same size as each of the original 40 linac cryomodules, each new cryomodule will have approximately 4 times the acceleration power. To support the additional cryomodule heat loads generated, the existing 2K, 4600W Central Helium Liquefier (CHL) plant capacity will be doubled to a total of 9200W at 2K plus 24,000W at 35K for shield loads. The specified base line process cycle has been modeled after the laboratory s "Ganni Helium Cycle" process technology. In addition, a fourth physics experimental "Hall D" will be constructed which will have an additional stand alone 200W at 4K helium cryogenic plant. In October of 2008, Jefferson Laboratory (JLab) received approval for project "Critical Decision 3" construction phase status from the US Department of Energy.

  10. Pulse-Shape Analysis of Ionization Signals in Cryogenic Ge Detectors for Dark Matter

    NASA Astrophysics Data System (ADS)

    Foerster, N.; Broniatowski, A.; Eitel, K.; Marnieros, S.; Paul, B.; Piro, M.-C.; Siebenborn, B.

    2016-08-01

    The detectors of the direct dark matter search experiment EDELWEISS consist of high-purity germanium crystals operated at cryogenic temperatures (mathrm {{<}20 mK}) and low electric fields (mathrm {{<}1 V/cm}). The surface discrimination is based on the simultaneous measurement of the charge amplitudes on different sets of electrodes. As the rise time of a charge signal strongly depends on the location of an interaction in the crystal, a time-resolved measurement can also be used to identify surface interactions. This contribution presents the results of a study of the discrimination power of the rise time parameter from a hot carrier transport simulation in combination with time-resolved measurements using an EDELWEISS-type detector in a test cryostat at ground level. We show the setup for the time-resolved ionization signal read-out in the EDELWEISS-III experiment and first results from data taking in the underground laboratory of Modane.

  11. Physics and performance of nanoscale semiconductor devices at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Balestra, F.; Ghibaudo, G.

    2017-02-01

    The physics and performance of various advanced semiconductor devices, which are the most promising for the end of the ITRS roadmap, are investigated in a wide temperature range down to 20 K. The transport parameters in front and/or back channels in fully depleted ultrathin film SOI devices, Trigate, FinFET, Omega-gate nanowire FET and 3D-stacked SiGe nanowire FETs, fabricated with high-k dielectrics/metal gate, elevated source/drain, different channel orientations, shapes and strains, are addressed. The impacts of the gate length, Si film and wire diameter down to 10 nm, are also shown. The variations of the phonon, Coulomb, neutral defects and surface roughness scattering as a function of temperature and device architecture are highlighted. An overview of the influence of temperature on other main electrical parameters of MOSFETs, nanowires FETs and tunnel FETs, such as threshold voltage, subthreshold swing, leakage and driving currents is also given.

  12. Process of making cryogenically cooled high thermal performance crystal optics

    DOEpatents

    Kuzay, Tuncer M.

    1992-01-01

    A method for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N.sub.2 is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation.

  13. Process of making cryogenically cooled high thermal performance crystal optics

    DOEpatents

    Kuzay, T.M.

    1992-06-23

    A method is disclosed for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N[sub 2] is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation. 7 figs.

  14. Cryogenic Thermal Performance Testing of Bulk-Fill and Aerogel Insulation Materials

    NASA Technical Reports Server (NTRS)

    Scholtens, B. E.; Fesmire, J. E.; Sass, J. P.; Augustynowicz, S. D.; Heckle, K. W.

    2007-01-01

    The research testing and demonstration of new bulk-fill materials for cryogenic thermal insulation systems was performed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. Thermal conductivity testing under actual-use cryogenic conditions is a key to understanding the total system performance encompassing engineering, economics, and materials factors. A number of bulk fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, were tested using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boil-off method were 293 K and 78 K. Tests were performed as a function of cold vacuum pressure from high vacuum to no vacuum conditions. Results are compared with other complementary test methods in the range of 300 K to 20 K. Various testing techniques are shown to be required to obtain a complete understanding of the operating performance of a material and to provide data for answers to design engineering questions.

  15. Cryogenic propellant management: Integration of design, performance and operational requirements

    NASA Technical Reports Server (NTRS)

    Worlund, A. L.; Jamieson, J. R., Jr.; Cole, T. W.; Lak, T. I.

    1985-01-01

    The integration of the design features of the Shuttle elements into a cryogenic propellant management system is described. The implementation and verification of the design/operational changes resulting from design deficiencies and/or element incompatibilities encountered subsequent to the critical design reviews are emphasized. Major topics include: subsystem designs to provide liquid oxygen (LO2) tank pressure stabilization, LO2 facility vent for ice prevention, liquid hydrogen (LH2) feedline high point bleed, pogo suppression on the Space Shuttle Main Engine (SSME), LO2 low level cutoff, Orbiter/engine propellant dump, and LO2 main feedline helium injection for geyser prevention.

  16. GeMS/GSAOI performances from a user perspective

    NASA Astrophysics Data System (ADS)

    Dalessandro, Emanuele; Saracino, Sara; Origlia, Livia; Marchetti, Enrico; Ferraro, Francesco R.; Lanzoni, Barbara; Geisler, Douglas; Mauro, Francesco

    2016-07-01

    Ground-based near-IR imagers assisted by Multi Conjugate Adaptive Optics (MCAO) systems are the technological frontier to obtain high-quality stellar photometry in crowded fields at the highest possible spatial resolution. The Gemini MCAO System (GeMS) feeding the Gemini South Adaptive Optics Imager (GSAOI) is the only facility of this kind currently available to the Community. We used a set of images obtained in the J and Ks bands of the central regions of two Galactic bulge globular clusters (Liller 1 and NGC 6624) with GeMS/GSAOI, under significantly different atmospheric conditions. We characterized the performances of the system in terms of efficiency and uniformity of the Point Spread Function (PSF) over the field of view with varying seeing, airmass and tip-tilt star asterisms. We also compared the PSF performances of GeMS/GSAOI with the HST/ACS ones in the F606W and F814W bands.

  17. Spiral 2 cryogenic system overview: Design, construction and performance test

    NASA Astrophysics Data System (ADS)

    Deschildre, C.; Bernhardt, J.; Flavien, G.; Crispel, S.; Souli, M.; Commeaux, C.

    2014-01-01

    The new particle accelerator project Spiral 2 at GANIL ("Grand Accélérateur d'Ions Lourds, i.e. National Large Heavy Ion Accelerator) in Caen (France) is a very large installation, intended to serve fundamental research in nuclear physics. The heart of the future machine features a superconductor linear accelerator, delivering a beam until 20Mev/A, which are then used to bombard a matter target. The resulting reactions, such as fission, transfer, fusion, etc. will generate billions of exotic nuclei. To achieve acceleration of the beam, 26 cavities which are placed inside cryomodules at helium cryogenic temperature will be used. AL-AT (Air Liquide Advanced Technologies) takes part to the project by supplying cryogenic plant. The plant includes the liquefier associated to its compressor station, a large dewar, a storage tank for helium gas and transfer lines. In addition, a helium recovery system composed of recovery compressor, high pressure storage and external purifier has been supplied. Customized HELIAL LF has been designed, manufactured and tested by AL-AT to match the refrigeration power need for the Spiral 2 project which is around 1300 W equivalent at 4.5 K.

  18. Spiral 2 cryogenic system overview: Design, construction and performance test

    SciTech Connect

    Deschildre, C.; Bernhardt, J.; Flavien, G.; Crispel, S.; Souli, M.; Commeaux, C.

    2014-01-29

    The new particle accelerator project Spiral 2 at GANIL (“Grand Accélérateur d’Ions Lourds, i.e. National Large Heavy Ion Accelerator) in Caen (France) is a very large installation, intended to serve fundamental research in nuclear physics. The heart of the future machine features a superconductor linear accelerator, delivering a beam until 20Mev/A, which are then used to bombard a matter target. The resulting reactions, such as fission, transfer, fusion, etc. will generate billions of exotic nuclei. To achieve acceleration of the beam, 26 cavities which are placed inside cryomodules at helium cryogenic temperature will be used. AL-AT (Air Liquide Advanced Technologies) takes part to the project by supplying cryogenic plant. The plant includes the liquefier associated to its compressor station, a large dewar, a storage tank for helium gas and transfer lines. In addition, a helium recovery system composed of recovery compressor, high pressure storage and external purifier has been supplied. Customized HELIAL LF has been designed, manufactured and tested by AL-AT to match the refrigeration power need for the Spiral 2 project which is around 1300 W equivalent at 4.5 K.

  19. Performance improvement for epitaxially grown SiGe on Si solar cell using a compositionally graded SiGe base

    NASA Astrophysics Data System (ADS)

    Li, Dun; Zhao, Xin; Wang, Li; Conrad, Brianna; Soeriyadi, Anastasia; Lochtefeld, Anthony; Gerger, Andrew; Perez-Wurfl, Ivan; Barnett, Allen

    2016-12-01

    Silicon germanium (SiGe) is a material with high mobility and relatively low bandgap making it an attractive candidate for the bottom subcell in a III-V tandem solar cell grown on silicon (Si) substrate. This paper reports on the performance improvement of an epitaxially grown SiGe on Si solar cell by growing a higher Ge composition SiGe layer in the base. The purpose of growing a higher Ge composition SiGe layer in the base is to improve the light absorption. The first iteration of this structure was an Si0.18Ge0.82 solar cell fabricated with a 1 μm thick Si0.12Ge0.88 layer in the base. This solar cell had a lower efficiency compared with the reference solar cell without the Si0.12Ge0.88 layer. One of the main reasons for the lower efficiency is believed to be the high threading dislocation density (TDD) caused by the abrupt change of lattice constant between Si0.18Ge0.82 and Si0.12Ge0.88 in the base. In order to reduce the TDD, the second iteration of the structure was fabricated with a compositionally graded SiGe base. With the new structure, an SiGe on Si solar cell with an efficiency of 3.1%, when filtered by a GaAs0.79P0.21 top cell, was fabricated. The Ge composition in the base of this solar cell gradually increased from 82% to 85% and then decreased again to 82%. The developed SiGe solar cell with graded base provides more flexibility for a highly efficient GaAsP/SiGe dual junction solar cell grown on an Si substrate.

  20. Cryogenic Temperature Effects on Performance of Polymer Composites

    NASA Technical Reports Server (NTRS)

    Hui, David; Dutta, P. K.

    2003-01-01

    The objective of this study is to evaluate the low temperature behavior of polymer composites down to the cryogenic temperature range. This would be accomplished by study of its behavior in several ways. First we would study the microfracture growth by observing the acoustic emission as the temperature is lowered. We would also note any damage growth by ultrasonic velocity testing applying the pulse echo method. Effects of such low temperature would then be studied by examining the shear properties by the short beam shear test, and also the fracture toughness properties over a wide range of strain rate and temperature. At present these studies are continuing. The limited data obtained from these studies are reported in this report.

  1. TankSIM: A Cryogenic Tank Performance Prediction Program

    NASA Technical Reports Server (NTRS)

    Bolshinskiy, L. G.; Hedayat, A.; Hastings, L. J.; Moder, J. P.; Schnell, A. R.; Sutherlin, S. G.

    2015-01-01

    Developed for predicting the behavior of cryogenic liquids inside propellant tanks under various environmental and operating conditions. Provides a multi-node analysis of pressurization, ullage venting and thermodynamic venting systems (TVS) pressure control using axial jet or spray bar TVS. Allows user to combine several different phases for predicting the liquid behavior for the entire flight mission timeline or part of it. Is a NASA in-house code, based on FORTRAN 90-95 and Intel Visual FORTRAN compiler, but can be used on any other platform (Unix-Linux, Compaq Visual FORTRAN, etc.). The last Version 7, released on December 2014, included detailed User's Manual. Includes the use of several RefPROP subroutines for calculating fluid properties.

  2. CEBAF SRF Performance during Initial 12 GeV Commissioning

    SciTech Connect

    Bachimanchi, Ramakrishna; Allison, Trent; Daly, Edward; Drury, Michael; Hovater, J; Lahti, George; Mounts, Clyde; Nelson, Richard; Plawski, Tomasz

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.

  3. Performance evaluation of a lossy transmission lines based diode detector at cryogenic temperature.

    PubMed

    Villa, E; Aja, B; de la Fuente, L; Artal, E

    2016-01-01

    This work is focused on the design, fabrication, and performance analysis of a square-law Schottky diode detector based on lossy transmission lines working under cryogenic temperature (15 K). The design analysis of a microwave detector, based on a planar gallium-arsenide low effective Schottky barrier height diode, is reported, which is aimed for achieving large input return loss as well as flat sensitivity versus frequency. The designed circuit demonstrates good sensitivity, as well as a good return loss in a wide bandwidth at Ka-band, at both room (300 K) and cryogenic (15 K) temperatures. A good sensitivity of 1000 mV/mW and input return loss better than 12 dB have been achieved when it works as a zero-bias Schottky diode detector at room temperature, increasing the sensitivity up to a minimum of 2200 mV/mW, with the need of a DC bias current, at cryogenic temperature.

  4. Performance evaluation of a lossy transmission lines based diode detector at cryogenic temperature

    NASA Astrophysics Data System (ADS)

    Villa, E.; Aja, B.; de la Fuente, L.; Artal, E.

    2016-01-01

    This work is focused on the design, fabrication, and performance analysis of a square-law Schottky diode detector based on lossy transmission lines working under cryogenic temperature (15 K). The design analysis of a microwave detector, based on a planar gallium-arsenide low effective Schottky barrier height diode, is reported, which is aimed for achieving large input return loss as well as flat sensitivity versus frequency. The designed circuit demonstrates good sensitivity, as well as a good return loss in a wide bandwidth at Ka-band, at both room (300 K) and cryogenic (15 K) temperatures. A good sensitivity of 1000 mV/mW and input return loss better than 12 dB have been achieved when it works as a zero-bias Schottky diode detector at room temperature, increasing the sensitivity up to a minimum of 2200 mV/mW, with the need of a DC bias current, at cryogenic temperature.

  5. PERFORMANCE OF A LIQUID XENON CALORIMETER CRYOGENIC SYSTEM FOR THE MEG EXPERIMENT

    SciTech Connect

    Haruyama, T.; Kasami, K.; Hisamitsu, Y.; Iwamoto, T.; Mihara, S.; Mori, T.; Nishiguchi, H.; Otani, W.; Sawada, R.; Uchiyama, Y.; Nishitani, T.

    2008-03-16

    The {mu}-particle rare decay physics experiment, the MU-E-GAMMA (MEG) experiment, will soon be operational at the Paul Scherrer Institute in Zurich. To achieve the extremely high sensitivity required to detect gamma rays, 800 L of liquid xenon is used as the medium in the calorimeter, viewed by 830 photomultiplier tubes (PMT) immersed in it. The required liquid xenon purity is of the order of ppb of water, and is obtained by using a cryogenic centrifugal pump and cold molecular sieves. The heat load of the calorimeter at 165 K is to be approximately 120 W, which is removed by a pulse-tube cryocooler developed at KEK and built by Iwatani Industrial Gas Corp., with a cooling power of about 200 W at 165 K. The cryogenic system is also equipped with a 1000-L dewar. This paper describes the results of an initial performance test of each cryogenic component.

  6. Design and thermodynamic performance analysis of multichannel cryogenic transfer line for XFEL AMTF

    NASA Astrophysics Data System (ADS)

    Duda, P.; Chorowski, M.; Polinski, J.

    2017-02-01

    The XATL1 cryogenic transfer line for XFEL/AMTF is dedicated for transferring cryogenic cooling power from helium refrigerators to a cryogenic test facility by means of the continuous flows of cold helium in supercritical and gaseous state. The external envelope of the transfer line contains 4 cold process lines and a common radiation shield, as well as the system of supports and thermal contraction compensators. The XATL1 was designed and manufactured within the Polish in-kind contribution to the XFEL project. The line has been under operation since year 2012. The paper presents a design, including supporting and thermal compensation systems, of the XATL1 line. The line performance analysis based on the Second Law of Thermodynamics has been done, and the output has been compared with the design assumptions.

  7. Demand Response Performance of GE Hybrid Heat Pump Water Heater

    SciTech Connect

    Widder, Sarah H.; Parker, Graham B.; Petersen, Joseph M.; Baechler, Michael C.

    2013-07-01

    This report describes a project to evaluate and document the DR performance of HPWH as compared to ERWH for two primary types of DR events: peak curtailments and balancing reserves. The experiments were conducted with GE second-generation “Brillion”-enabled GeoSpring hybrid water heaters in the PNNL Lab Homes, with one GE GeoSpring water heater operating in “Standard” electric resistance mode to represent the baseline and one GE GeoSpring water heater operating in “Heat Pump” mode to provide the comparison to heat pump-only demand response. It is expected that “Hybrid” DR performance, which would engage both the heat pump and electric elements, could be interpolated from these two experimental extremes. Signals were sent simultaneously to the two water heaters in the side-by-side PNNL Lab Homes under highly controlled, simulated occupancy conditions. This report presents the results of the evaluation, which documents the demand-response capability of the GE GeoSpring HPWH for peak load reduction and regulation services. The sections describe the experimental protocol and test apparatus used to collect data, present the baselining procedure, discuss the results of the simulated DR events for the HPWH and ERWH, and synthesize key conclusions based on the collected data.

  8. Flight Performance of Gravity Probe B Cryogenic System

    NASA Astrophysics Data System (ADS)

    Murray, D. O.; Taber, M. A.; Burns, K. M.

    2006-04-01

    Gravity Probe B (GP-B) is a cryogenic and space-based test of Einstein's General Theory of Relativity by means of precision gyroscopes, The GP-B spacecraft was launched into a polar orbit from Vandenberg AFB on April 20, 2004. The launch and operation of GP-B represented the culmination of forty years of planning, technology development, hardware fabrication, and testing. The superfluid liquid helium became depleted on September 29, 2005, giving a lifetime of 17.3 months compared to the requirement of 16.5 months and a thermal model prediction of 16.6 months. The flight dewar contained 2320 liters of ~1.8 K superfluid helium at launch and housed the science instrument consisting of four precision gyroscopes and a telescope. A porous plug phase separator effected the venting of the helium boiloff gas. This venting helium was used to operate 16 thrusters, which are the actuators that effect precision pointing on a fixed star and adjust the orbit to be drag free or close to true zero-g.

  9. High frequency performance of Si(1-x)Ge(x)/Si(1-y)Ge(y)/Si(1-x)Ge(x) HBTs

    NASA Technical Reports Server (NTRS)

    Rosenfeld, D.; Alterovitz, S. A.

    1993-01-01

    The results of a theoretical study of the performance of high speed SiGe HBTs is presented. The study includes a group of SiGe HBTs in which the Ge concentration in the base is 20 percent higher than that in the emitter and collector (i.e., y = x + 0.2). It is shown that the composition dependences of f(T) and the f(max) are nonmonotonic. As the Ge composition in the emitter and collector layers is increased, f(T) and f(max) first decrease, then remain constant and finally increase to attain their highest values.

  10. Impacts of plasma-induced damage due to UV light irradiation during etching on Ge fin fabrication and device performance of Ge fin field-effect transistors

    NASA Astrophysics Data System (ADS)

    Mizubayashi, Wataru; Noda, Shuichi; Ishikawa, Yuki; Nishi, Takashi; Kikuchi, Akio; Ota, Hiroyuki; Su, Ping-Hsun; Li, Yiming; Samukawa, Seiji; Endo, Kazuhiko

    2017-02-01

    We investigated the impacts of plasma-induced damage due to UV light irradiation during etching on Ge fin fabrication and the device performance of Ge fin field-effect transistors (Ge FinFETs). UV light irradiation during etching affected the shape of the Ge fin and the surface roughness of the Ge fin sidewall. A vertical and smooth Ge fin could be fabricated by neutral beam etching without UV light irradiation. The performances of Ge FinFETs fabricated by neutral beam etching were markedly improved as compared to those of Ge FinFETs fabricated by inductively coupled plasma etching, in which the UV light has an impact.

  11. The cryogenic on-orbit liquid analytical tool (COOLANT) - A computer program for evaluating the thermodynamic performance of orbital cryogen storage facilities

    NASA Technical Reports Server (NTRS)

    Taylor, W. J.; Honkonen, S. C.; Williams, G. E.; Liggett, M. W.; Tucker, S. P.

    1991-01-01

    The United States plans to establish a permanent manned presence at the Space Station Freedom in low earth orbit (LEO) and then carry out exploration of the solar system from this base. These plans may require orbital cryogenic propellant storage depots. The COOLANT program has been developed to analyze the thermodynamic performance of these depots to support design tradeoff studies. It was developed as part of the Long Term Cryogenic Storage Facility Systems Study for NASA/MSFC. This paper discusses the program structure and capabilities of the COOLANT program. In addition, the results of an analysis of a 200,000 lbm hydrogen/oxygen storage depot tankset using COOLANT are presented.

  12. Modifications to JLab 12 GeV Refrigerator and Wide Range Mix Mode Performance Testing Results

    NASA Astrophysics Data System (ADS)

    Knudsen, P.; Ganni, V.; Hasan, N.; Dixon, K.; Norton, R.; Creel, J.

    2017-02-01

    Analysis of data obtained during the spring 2013 commissioning of the new 4.5 K refrigeration system at Jefferson Lab (JLab) for the 12 GeV upgrade indicated a wide capacity range with good efficiency and minimal operator interaction. Testing also showed that the refrigerator required higher liquid nitrogen (LN) consumption for its pre-cooler than anticipated by the design. This does not affect the capacity of the refrigerator, but it does result in an increased LN utility cost. During the summer of 2015 the modifications were implemented by the cold box manufacturer, according to a design similar to the JLab 12 GeV cold box specification. Subsequently, JLab recommissioned the cold box and performed extensive performance testing, ranging from 20% to 100% of the design maximum capacity, and in various modes of operation, ranging from pure refrigeration, pure liquefaction, half-and-half mix mode and at selected design modes using the Floating Pressure – Ganni Cycle. The testing demonstrated that the refrigerator system has a good and fairly constant performance over a wide capacity range and different modes of operation. It also demonstrated the modifications resulted in a LN consumption that met the design for the pure refrigeration mode (which is the most demanding) and was lower than the design for the nominal and maximum capacity modes. In addition, a pulsed-load test, similar to what is expected for cryogenic systems supporting fusion experiments, was conducted to observe the response using the Floating Pressure – Ganni Cycle, which was stable and robust. This paper will discuss the results and analysis of this testing pertaining to the LN consumption, the system efficiency over a wide range of capacity and different modes and the behaviour of the system to a pulsed load.

  13. On the selection of materials for cryogenic seals and the testing of their performance

    NASA Technical Reports Server (NTRS)

    Russell, John M.

    1989-01-01

    Three questions are addressed: what mission must a cryogenic seal perform; what are the contrasts between desirable and available seal materials; and how realistic must test conditions be. The question of how to quantify the response of a material subject to large strains and which is susceptible to memory effects leads to a discussion of theoretical issues. Accordingly, the report summarizes some ideas from the rational mechanics of materials. The report ends with a list of recommendations and a conclusion.

  14. Net Shape Spin Formed Cryogenic Aluminum Lithium Cryogenic Tank Domes for Lower Cost Higher Performance Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.; Hoffman, Eric; Domack, Marcia; Brewster, Jeb; Russell, Carolyn

    2013-01-01

    With the goal of lower cost (simplified manufacturing and lower part count) and higher performance (higher strength to weight alloys) the NASA Technical Maturation Program in 2006 funded a proposal to investigate spin forming of space launch vehicle cryogenic tank domes. The project funding continued under the NASA Exploration Technology Development Program through completion in FY12. The first phase of the project involved spin forming of eight, 1 meter diameter "path finder" domes. Half of these were processed using a concave spin form process (MT Aerospace, Augsburg Germany) and the other half using a convex process (Spincraft, Boston MA). The convex process has been used to produce the Ares Common Bulkhead and the concave process has been used to produce dome caps for the Space Shuttle light weight external tank and domes for the NASDA H2. Aluminum Lithium material was chosen because of its higher strength to weight ratio than the Aluminum 2219 baseline. Aluminum lithium, in order to obtain the desired temper (T8), requires a cold stretch after the solution heat treatment and quench. This requirement favors the concave spin form process which was selected for scale up. This paper describes the results of processing four, 5.5 meter diameter (upper stage scale) net shaped spin formed Aluminum Lithium domes. In order to allow scalability beyond the limits of foundry and rolling mills (about 12 foot width) the circular blank contained one friction stir weld (heavy lifter scales require a flat blank containing two welds). Mechanical properties data (tensile, fracture toughness, stress corrosion, and simulated service testing) for the parent metal and weld will also be discussed.

  15. Automatic PID Control Loops Design for Performance Improvement of Cryogenic Turboexpander

    NASA Astrophysics Data System (ADS)

    Joshi, D. M.; Patel, H. K.; Shah, D. K.

    2015-04-01

    Cryogenics field involves temperature below 123 K which is much less than ambient temperature. In addition, many industrially important physical processes—from fulfilling the needs of National Thermonuclear Fusion programs, superconducting magnets to treatment of cutting tools and preservation of blood cells, require extreme low temperature. The low temperature required for liquefaction of common gases can be obtained by several processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Helium liquefier is used for the liquefaction process of helium gas. In general, the Helium Refrigerator/Liquefier (HRL) needs turboexpander as expansion machine to produce cooling effect which is further used for the production of liquid helium. Turboexpanders, a high speed device that is supported on gas bearings, are the most critical component in many helium refrigeration systems. A very minor fault in the operation and manufacturing or impurities in the helium gas can destroy the turboexpander. However, since the performance of expanders is dependent on a number of operating parameters and the relations between them are quite complex, the instrumentation and control system design for turboexpander needs special attention. The inefficiency of manual control leads to the need of designing automatic control loops for turboexpander. Proper design and implementation of the control loops plays an important role in the successful operation of the cryogenic turboexpander. The PID control loops has to be implemented with accurate interlocks and logic to enhance the performance of the cryogenic turboexpander. For different normal and off-normal operations, speeds will be different and hence a proper control method for critical rotational speed avoidance is must. This paper presents the design of PID control loops needed for the

  16. Cryogenic Performance of Trex SiC Mirror

    NASA Technical Reports Server (NTRS)

    Foss, Colby; Kane, Dave; Bray, Donald; Hadaway, James

    2005-01-01

    Low cost, high performance lightweight Silicon Carbide (Sic) mirrors provide an alternative to Beryllium mirrors. A Trex Enterprises 0.25m diameter lightweight Sic mirror using its patented Chemical Vapor Composites (CVC) technology was evaluated for its optical performance. CVC Sic is chemically pure, thermally stable, and mechanically stiff. CVC technology yields higher growth rate than that of CVD Sic. NASA has funded lightweight optical materials technology development efforts involving Sic mirrors for future space based telescope programs. As part of these efforts, a Trex Sic was measured interferometrically from room temperature to 30 degrees Kelvin. This paper will discuss the test goals, the test instrumentation, test results, and lessons learned.

  17. An ultralightweight, evacuated, load-bearing, high-performance insulation system. [for cryogenic propellant tanks

    NASA Technical Reports Server (NTRS)

    Parmley, R. T.; Cunnington, G. R., Jr.

    1978-01-01

    A new hollow-glass microsphere insulation and a flexible stainless-steel vacuum jacket were demonstrated on a flight-weight cryogenic test tank, 1.17 m in diameter. The weight of the system is three times lighter than the most advanced vacuum-jacketed design demonstrated to date, a free-standing honeycomb hard shell with a multilayer insulation system (for a Space Tug application). Design characteristics of the flexible vacuum jacket are presented along with a model describing the insulation thermal performance as a function of boundary temperatures and emittance, compressive load on the insulation and insulation gas pressure. Test data are compared with model predictions and with prior flat-plate calorimeter test results. Potential applications for this insulation system or a derivative of this system include the cryogenic Space Tug, the Single-Stage-to-Orbit Space Shuttle, LH2 fueled subsonic and hypersonic aircraft, and LNG applications.

  18. Power electronics performance in cryogenic environment: evaluation for use in HTS power devices

    NASA Astrophysics Data System (ADS)

    Pereira, P.; Valtchev, S.; Pina, J.; Gonçalves, A.; Ventim Neves, M.; Rodrigues, A. L.

    2008-02-01

    Power electronics (PE) plays a major role in electrical devices and systems, namely in electromechanical drives, in motor and generator controllers, and in power grids, including high-voltage DC (HVDC) power transmission. PE is also used in devices for the protection against grid disturbances, like voltage sags or power breakdowns. To cope with these disturbances, back-up energy storage devices are used, like uninterruptible power supplies (UPS) and flywheels. Some of these devices may use superconductivity. Commercial PE semiconductor devices (power diodes, power MOSFETs, IGBTs, power Darlington transistors and others) are rarely (or never) experimented for cryogenic temperatures, even when designed for military applications. This means that its integration with HTS power devices is usually done in the hot environment, raising several implementation restrictions. These reasons led to the natural desire of characterising PE under extreme conditions, e. g. at liquid nitrogen temperatures, for use in HTS devices. Some researchers expect that cryogenic temperatures may increase power electronics' performance when compared with room-temperature operation, namely reducing conduction losses and switching time. Also the overall system efficiency may increase due to improved properties of semiconductor materials at low temperatures, reduced losses, and removal of dissipation elements. In this work, steady state operation of commercial PE semiconductors and devices were investigated at liquid nitrogen and room temperatures. Performances in cryogenic and room temperatures are compared. Results help to decide which environment is to be used for different power HTS applications.

  19. Effects of Forged Stock and Pure Aluminum Coating on Cryogenic Performance of Heat Treated Aluminum Mirrors

    NASA Technical Reports Server (NTRS)

    Toland, Ronald; Ohl, Raymond G.; Barthelmy, Michael P.; Zewari, S. Wahid; Greenhouse, Matthew A.; MacKenty, John W.

    2003-01-01

    In spite of its baseline mechanical stress relief, aluminum 6061-T651 harbors some residual stress that may relieve and distort mirror figure to unacceptable levels at cryogenic operating temperatures unless relieved during fabrication. Cryogenic instruments using aluminum mirrors for both ground-based and space IR astronomy have employed a variety of heat treatment formulae, with mixed results. We present the results of an on-going test program designed to empirically determine the effects of different stress relief procedures for aluminum mirrors. Earlier test results identified a preferred heat treatment for flat and spherical mirrors diamond turned from blanks cut out of Al6061-T651 plate stock. Further tests have been performed on mirrors from forged stock and one set from plate stock coated with Alumiplate(TM) aluminum coating to measure the effect of these variables on cryogenic performance. The mirrors are tested for figure error and radius of curvature at room temperature and at 80 K for three thermal cycles. We correlate the results of our optical testing with heat treatment and metallographic data.

  20. Cryogenic Performance of a Lightweight Silicon Carbide Mirror

    NASA Technical Reports Server (NTRS)

    Eng, Ron; Carpenter, James; Haight, Harlan; Hogue, William; Kegley, Jeff; Stahl, H. Philip; Wright, Ernie; Kane, Dave; Hadaway, James

    2005-01-01

    Low cost, high performance lightweight Silicon Carbide (SiC) mirrors provide an alternative to Beryllium mirrors. A Trex Enterprises 0.25m diameter lightweight SiC mirror using its patented Chemical Vapor Composites (CVC) technology was evaluated for its optical performance. CVC SiC is chemically pure, thermally stable, and mechanically stiff. CVC technology yields higher growth rate than that of CVD SiC. NASA has funded lightweight optical materials technology development efforts involving SiC mirrors for future space based telescope programs. As part of these efforts, a Trex SiC was measured interferometrically from room temperature to 30 degrees Kelvin. This paper will discuss the test goals, the test instrumentation, test results, and lessons learned.

  1. Refrigeration for Cryogenic Sensors

    SciTech Connect

    Gasser, M.G.

    1983-12-01

    Research in cryogenically cooled refrigerators is discussed. Low-power Stirling cryocoolers; spacecraft-borne long-life units; heat exchangers; performance tests split-stirling, linear-resonant, cryogenic refrigerators; and computer models are among the topics discussed.

  2. Refrigeration for Cryogenic Sensors

    NASA Technical Reports Server (NTRS)

    Gasser, M. G. (Editor)

    1983-01-01

    Research in cryogenically cooled refrigerators is discussed. Low-power Stirling cryocoolers; spacecraft-borne long-life units; heat exchangers; performance tests; split-stirling, linear-resonant, cryogenic refrigerators; and computer models are among the topics discussed.

  3. Cryogenic performance of a cryocooler-cooled superconducting undulator

    SciTech Connect

    Fuerst, J. D.; Doose, C.; Hasse, Q.; Ivanyushenkov, Y.; Kasa, M.; Shiroyanagi, Y.

    2014-01-29

    A cryocooler-cooled superconducting undulator has been installed and operated with beam at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The device consists of a dual-core 42-pole magnet structure that is cooled to 4.2 K with a system of four cryocoolers operating in a zero-boil-off configuration. This effort represents the culmination of a development program to establish concept feasibility and evaluate cryostat design and cryocooler-based refrigeration. Cryostat performance is described including cool-down/warm-up, steady-state operation, cooling margin, and the impact of beam during operation in the APS storage ring. Plans for future devices with longer magnets, which will incorporate lessons learned from the development program, are also discussed.

  4. Cryogenic performance of a cryocooler-cooled superconducting undulator

    NASA Astrophysics Data System (ADS)

    Fuerst, J. D.; Doose, C.; Hasse, Q.; Ivanyushenkov, Y.; Kasa, M.; Shiroyanagi, Y.

    2014-01-01

    A cryocooler-cooled superconducting undulator has been installed and operated with beam at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). The device consists of a dual-core 42-pole magnet structure that is cooled to 4.2 K with a system of four cryocoolers operating in a zero-boil-off configuration. This effort represents the culmination of a development program to establish concept feasibility and evaluate cryostat design and cryocooler-based refrigeration. Cryostat performance is described including cool-down/warm-up, steady-state operation, cooling margin, and the impact of beam during operation in the APS storage ring. Plans for future devices with longer magnets, which will incorporate lessons learned from the development program, are also discussed.

  5. Cryogenic Optical Performance of the Cassini Composite InfraRed Spectrometer (CIRS) Flight Telescope

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James J., III; Hagopian, John

    1998-01-01

    The CIRS half-meter diameter beryllium flight telescope's optical performance was tested at the instrument operating temperature of 170 Kelvin. The telescope components were designed at Goddard Space Flight Center (GSFC) but fabricated out of house and then assembled, aligned and tested upon receipt at GSFC. A 24 inch aperture cryogenic test facility utilizing a 1024 x 1024 CCD array was developed at GSFC specifically for this test. The telescope,s image quality (measured as encircled energy), boresight stability and focus stability were measured. The gold coated beryllium design exceeded the cold image performance requirement of 80% encircled energy within a 460 micron diameter circle.

  6. Thermal Performance Testing of Cryogenic Multilayer Insulation with Silk Net Spacers

    NASA Astrophysics Data System (ADS)

    Johnson, W. L.; Frank, D. J.; Nast, T. C.; Fesmire, J. E.

    2015-12-01

    Early comprehensive testing of cryogenic multilayer insulation focused on the use of silk netting as a spacer material. Silk netting was used for multiple test campaigns that were designed to provide baseline thermal performance estimates for cryogenic insulation systems. As more focus was put on larger systems, the cost of silk netting became a deterrent and most aerospace insulation firms were using Dacron (or polyester) netting spacers by the early 1970s. In the midst of the switch away from silk netting there was no attempt to understand the difference between silk and polyester netting, though it was widely believed that the silk netting provided slightly better performance. Without any better reference for thermal performance data, the silk netting performance correlations continued to be used. In order to attempt to quantify the difference between the silk netting and polyester netting, a brief test program was developed. The silk netting material was obtained from Lockheed Martin and was tested on the Cryostat-100 instrument in three different configurations, 20 layers with both single and double netting and 10 layers with single netting only. The data show agreement within 15 - 30% with the historical silk netting based correlations and show a substantial performance improvement when compared to previous testing performed using polyester netting and aluminum foil/fiberglass paper multilayer insulation. Additionally, the data further reinforce a recently observed trend that the heat flux is not directly proportional to the number of layers installed on a system.

  7. Potential improvements in SiGe radioisotope thermoelectric generator performance

    SciTech Connect

    Mowery, A.L.

    1999-01-01

    In accordance with NASA{close_quote}s slogan: {open_quotes}Better, Cheaper, Faster,{close_quotes} this paper will address potential improvements to SiGe RTG technology to make them Better. RTGs are doubtless cheaper than {open_quotes}paper designs{close_quotes} which are better and cheaper until development, performance and safety test costs are considered. RTGs have the advantage of being fully developed and tested in the rigors of space for over twenty years. Further, unless a new system can be accelerated tested, as were the RTGs, they cannot be deployed reliably unless a number of systems have succeeded for test periods exceeding the mission lifetime. Two potential developments are discussed that can improve the basic RTG performance by 10 to 40{sup +}{percent} depending on the mission profile. These improvements could be demonstrated in years. Accelerated testing could also be performed in this period to preserve existing RTG reliability. Data from a qualification tested RTG will be displayed, while not definitive, to support the conclusions. Finally, it is anticipated that other investigators will be encouraged to suggest further modifications to the basic RTG design to improve its performance. {copyright} {ital 1999 American Institute of Physics.}

  8. Characteristics and performance of the ESTEC large space simulator cryogenic system

    NASA Technical Reports Server (NTRS)

    Amlinger, H.; Bosma, S. J.

    1986-01-01

    The final concept and performance characteristics of the Large Space Simulator (LSS) at ESTEC, The Netherlands are discussed. The LSS cryogenics system has proven its operational capabilities under simulated heat load conditions and provides sufficient margin for future elevated requirements. The acceptance test proved that nominal operating pressures can be lower than the design parameters, providing increased system safety and reliability. The ease of access for repair and the incorporated redundancy will limit system downtime. Finally, the system design resulted in a low consumption of LN sub 2, which is an important factor in keeping the operational costs at a low level.

  9. GeGI (Germanium Gamma Imager) Performance: Maritime Interdiction Operation

    SciTech Connect

    Dreyer, Jonathan G.; Burks, Morgan T.; Trombino, Dave

    2014-09-23

    The Gamma Ray Imager (GeGI) was demonstrated during the Maritime Interdiction Operation at Point Alameda, the site of the former Naval Air Station, in Alameda, CA. During this exercise GeGI was used to localize sources within an abandoned building and a cargo ship, the Admiral Callaghan.

  10. Updated cryogenic performance test results for the flight model JWST fine guidance sensor

    NASA Astrophysics Data System (ADS)

    Rowlands, Neil; Beaton, Alexander; Chayer, Pierre; Haley, Craig; Midwinter, Calvin; Volk, Kevin; Warner, Gerry; Zhou, Julia

    2016-07-01

    The Integrated Science Instrument Module (ISIM) for the James Webb Space Telescope (JWST) has successfully completed its final cryogenic performance verification tests. The performance of the newly upgraded Fine Guidance Sensor (FGS) / Near Infrared Imager and Slitless Spectrometer (NIRISS) was evaluated in these tests. We describe some of the key guider performance results which have been obtained and compare them to previous results with an older generation of H2RG infrared detector arrays. The identification mode sensitivity improvement is described along with noise equivalent angle (NEA) sensitivity performance improvements in tracking and fine guiding modes. Tracking mode allows the Observatory line of sight to settle in advance of the fine guidance mode and also facilitates moving target observing. The NEA of the FGS-Guiders will in part determine the ultimate image quality of the JWST Observatory.

  11. Performance of the Primary Mirror Center-of-Curvature Optical Metrology System during Cryogenic Testing of the JWST Pathfinder Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

    2016-01-01

    The JWST primary mirror consists of 18 1.5 m hexagonal segments, each with 6-DoF and RoC adjustment. The telescope will be tested at its cryogenic operating temperature at Johnson Space Center. The testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The performance of these metrology systems, including hardware, software, procedures, was assessed during two cryogenic tests at JSC, using the JWST Pathfinder telescope. This paper describes the test setup, the testing performed, and the resulting metrology system performance.

  12. Performance of smart piezoelectric transducers for structural health monitoring on composite laminates in cryogenic environments

    NASA Astrophysics Data System (ADS)

    Tseng, Kevin K.; Tinker, Michael L.; Lassiter, John O.; Wang, Liangsheng

    2004-07-01

    An important way of increasing the payload in a reusable launch vehicle (RLV) is to replace heavy metallic materials by lightweight composite laminates. Engineers and scientists have studied many metallic materials thoroughly, due to the long history of practical usage in many aerospace and aeronautical structures. Compared to metallic materials, composite laminates are a relatively new material and therefore require more attention to ensure the safety and reliability. Among various parts and systems of the RLV, this study focuses on tanks containing cryogenic fuel. Historically, aluminum alloys have been used as the materials to construct fuel tanks for launch vehicles. To replace aluminum alloys with composite laminates or honeycomb materials, engineers have to make sure that the composites are free of defects before, during, and after launch. In addition to robust design and manufacturing procedures, the performance of the composite structures needs to be evaluated constantly. In recent years, the impedance-based health monitoring technique has shown its promise in many applications. This technique makes use of the special properties of smart piezoelectric materials to identify the change of material properties due to the nucleation and progression of damage. A major advantage of this technique is that the procedure is nondestructive in nature and does not perturb the properties and performance of the materials and structures. This paper reports the results of applying the impedance-based nondestructive testing technique to the damage identification of composite laminates at cryogenic temperature. These materials have potential application for fuel tanks in future RLV"s.

  13. FRIB Cryogenic Plant Status

    SciTech Connect

    Dixon, Kelly D.; Ganni, Venkatarao; Knudsen, Peter N.; Casagranda, Fabio

    2015-12-01

    After practical changes were approved to the initial conceptual design of the cryogenic system for MSU FRIB and an agreement was made with JLab in 2012 to lead the design effort of the cryogenic plant, many activities are in place leading toward a cool-down of the linacs prior to 2018. This is mostly due to using similar equipment used at CHLII for the 12 GeV upgrade at JLab and an aggressive schedule maintained by the MSU Conventional Facilities department. Reported here is an updated status of the cryogenic plant, including the equipment procurement status, plant layout, facility equipment and project schedule.

  14. Operation and performance of the ICARUS T600 cryogenic plant at Gran Sasso underground Laboratory

    NASA Astrophysics Data System (ADS)

    Antonello, M.; Aprili, P.; Baibussinov, B.; Boffelli, F.; Bubak, A.; Calligarich, E.; Canci, N.; Centro, S.; Cesana, A.; Cieślik, K.; Cline, D. B.; Cocco, A. G.; Dabrowska, A.; Dermenev, A.; Disdier, J. M.; Falcone, A.; Farnese, C.; Fava, A.; Ferrari, A.; Gibin, D.; Gninenko, S.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Ivashkin, A.; Kirsanov, M.; Kisiel, J.; Kochanek, I.; Lagoda, J.; Mania, S.; Menegolli, A.; Meng, G.; Montanari, C.; Otwinowski, S.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G. L.; Rossella, M.; Rubbia, C.; Sala, P. R.; Scaramelli, A.; Segreto, E.; Sergiampietri, F.; Stefan, D.; Sulej, R.; Szarska, M.; Terrani, M.; Torti, M.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H. G.; Yang, X.; Zalewska, A.; Zani, A.; Zaremba, K.

    2015-12-01

    ICARUS T600 liquid argon time projection chamber is the first large mass electronic detector of a new generation able to combine the imaging capabilities of the old bubble chambers with an excellent calorimetric energy measurement. After the three months demonstration run on surface in Pavia during 2001, the T600 cryogenic plant was significantly revised, in terms of reliability and safety, in view of its long term operation in an underground environment. The T600 detector was activated in Hall B of the INFN Gran Sasso Laboratory during spring 2010, where it was operated without interruption for about three years, taking data exposed to the CERN to Gran Sasso long baseline neutrino beam (CNGS) and cosmic rays. In this paper the T600 cryogenic plant is described in detail together with the commissioning procedures that lead to the successful operation of the detector shortly after the end of the filling with liquid argon. Overall plant performance and stability during the underground run are discussed. Finally, the decommissioning procedures, carried out about six months after the end of the CNGS neutrino beam operation, are reported.

  15. Thermodynamic Control System for cryogenic propellant storage : experimental and analytical performance assessment

    NASA Astrophysics Data System (ADS)

    Mer, Samuel; Thibault, Jean-Paul; Corre, Christophe

    2016-11-01

    Future operations in space exploration require to store cryogens for long duration. Residual heat loads induce cryogenic propellant vaporization and tank self-pressurization (SP), eventually leading to storage failure for large enough mission duration. The present study focuses on the Thermodynamic Venting System (TVS) control strategy : liquid propellant is pumped from the tank, cooled down by a heat exchanger and re-injected, as a jet, inside the tank. The injection is followed by vapor condensation and liquid bath destratification due to mixing. The system cold source is created thanks to a Vented Branch where a liquid fraction is withdrawn from the tank and expanded through a Joule-Thomson valve. The vented branch vaporization permits to cool down the injection loop. Quantitative analyses of SP and TVS control have been experimentally performed using a 110 L tank and a simulant fluid. A database of accurate temperature and pressure dynamics has been gathered and used to validate a homogeneous thermodynamic model which provides a fast prediction of the tank dynamics. The analytical model has been coupled with a multi-objective optimizer to identify system components and regulation strategies that maximize the tank storage duration for various mission types. The authors acknowledge the joint support of the Centre National d'Etudes Spatiales and Air Liquide Advanced Technologies.

  16. Cryogenic irradiation of an EMCCD for the WFIRST coronagraph: preliminary performance analysis

    NASA Astrophysics Data System (ADS)

    Bush, Nathan; Hall, David; Holland, Andrew; Burgon, Ross; Murray, Neil; Gow, Jason; Jordan, Douglas; Demers, Richard; Harding, Leon K.; Nemati, Bijan; Hoenk, Michael; Michaels, Darren; Peddada, Pavani

    2016-08-01

    The Wide Field Infra-Red Survey Telescope (WFIRST) is a NASA observatory scheduled to launch in the next decade that will settle essential questions in exoplanet science. The Wide Field Instrument (WFI) offers Hubble quality imaging over a 0.28 square degree field of view and will gather NIR statistical data on exoplanets through gravitational microlensing. An on-board coronagraph will for the first time perform direct imaging and spectroscopic analysis of exoplanets with properties analogous to those within our own solar system, including cold Jupiters, mini Neptunes and potentially super Earths. The Coronagraph Instrument (CGI) will be required to operate with low signal flux for long integration times, demanding all noise sources are kept to a minimum. The Electron Multiplication (EM)-CCD has been baselined for both the imaging and spectrograph cameras due its ability to operate with sub-electron effective read noise values with appropriate multiplication gain setting. The presence of other noise sources, however, such as thermal dark signal and Clock Induced Charge (CIC), need to be characterized and mitigated. In addition, operation within a space environment will subject the device to radiation damage that will degrade the Charge Transfer Effciency (CTE) of the device throughout the mission lifetime. Irradiation at the nominal instrument operating temperature has the potential to provide the best estimate of performance degradation that will be experienced in-flight, since the final population of silicon defects has been shown to be dependent upon the temperature at which the sensor is irradiated. Here we present initial findings from pre- and post- cryogenic irradiation testing of the e2v CCD201-20 BI EMCCD sensor, baselined for the WFIRST coronagraph instrument. The motivation for irradiation at cryogenic temperatures is discussed with reference to previous investigations of a similar nature. The results are presented in context with those from a previous

  17. Performance of High-Speed PWM Control Chips at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Elbuluk, Malik E.; Gerber, Scott; Hammoud, Ahmad; Patterson, Richard; Overton, Eric

    2001-01-01

    The operation of power electronic systems at cryogenic temperatures is anticipated in many NASA space missions such as planetary exploration and deep space probes. In addition to surviving the space hostile environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing development and launch costs. As part of the NASA Glenn Low Temperature Electronics Program, several commercial high-speed Pulse Width Modulation (PWM) chips have been characterized in terms of their performance as a function of temperature in the range of 25 to -196 C (liquid nitrogen). These chips ranged in their electrical characteristics, modes of control, packaging options, and applications. The experimental procedures along with the experimental data obtained on the investigated chips are presented and discussed.

  18. Effects of Forged Stock and Pure Aluminum Coating on Cryogenic Performance of Heat Treated Aluminum Mirrors

    NASA Technical Reports Server (NTRS)

    Toland, Ronald W.; Ohl, Raymond G.; Barthelmy, Michael P.; Zewari, S. Wahid; Greenhouse, Matthew A.; MacKenty, John W.

    2003-01-01

    We present the results of an on-going test program designed to empirically determine the effects of different stress relief procedures for aluminum mirrors. Earlier test results identified a preferred heat treatment for flat and spherical mirrors diamond turned from blanks cut out of Al 6061-T651 plate stock. Further tests have been performed on mirrors from forged stock and one set from plate stock coated with Alumiplate(trademark) aluminum coating to measure the effect of these variables on cryogenic performance. The mirrors are tested for figure error and radius of curvature at room temperature and at 80 K for three thermal cycles. We correlate the results of our optical testing with heat treatment and metallographic data.

  19. A review of cryogenic testing performed by the thermochemical test branch, Manned Spacecraft Center in support of Apollo 13 and14

    NASA Technical Reports Server (NTRS)

    Propp, C. E.; Mcgee, J. M.

    1971-01-01

    The Apollo 13 anomaly provided considerable impetus for a variety of types of cryogenic and ignition tests. The logic of the various test program designs, the test techniques, and their final impact upon the investigation findings are described. In addition, several test programs initiated to determine the thermal performance and general performance characteristics of the redesigned Apollo 14 cryogenic storage system are presented.

  20. Experimental investigation on pressurization performance of cryogenic tank during high-temperature helium pressurization process

    NASA Astrophysics Data System (ADS)

    Lei, Wang; Yanzhong, Li; Yonghua, Jin; Yuan, Ma

    2015-03-01

    Sufficient knowledge of thermal performance and pressurization behaviors in cryogenic tanks during rocket launching period is of importance to the design and optimization of a pressurization system. In this paper, ground experiments with liquid oxygen (LO2) as the cryogenic propellant, high-temperature helium exceeding 600 K as the pressurant gas, and radial diffuser and anti-cone diffuser respectively at the tank inlet were performed. The pressurant gas requirements, axial and radial temperature distributions, and energy distributions inside the propellant tank were obtained and analyzed to evaluate the comprehensive performance of the pressurization system. It was found that the pressurization system with high-temperature helium as the pressurant gas could work well that the tank pressure was controlled within a specified range and a stable discharging liquid rate was achieved. For the radial diffuser case, the injected gas had a direct impact on the tank inner wall. The severe gas-wall heat transfer resulted in about 59% of the total input energy absorbed by the tank wall. For the pressurization case with anti-cone diffuser, the direct impact of high-temperature gas flowing toward the liquid surface resulted in a greater deal of energy transferred to the liquid propellant, and the percentage even reached up to 38%. Moreover, both of the two cases showed that the proportion of energy left in ullage to the total input energy was quite small, and the percentage was only about 22-24%. This may indicate that a more efficient diffuser should be developed to improve the pressurization effect. Generally, the present experimental results are beneficial to the design and optimization of the pressurization system with high-temperature gas supplying the pressurization effect.

  1. Design, construction and cooling system performance of a prototype cryogenic stopping cell for the Super-FRS at FAIR

    NASA Astrophysics Data System (ADS)

    Ranjan, M.; Dendooven, P.; Purushothaman, S.; Dickel, T.; Reiter, M. P.; Ayet, S.; Haettner, E.; Moore, I. D.; Kalantar-Nayestanaki, N.; Geissel, H.; Plaß, W. R.; Schäfer, D.; Scheidenberger, C.; Schreuder, F.; Timersma, H.; Van de Walle, J.; Weick, H.

    2015-01-01

    A cryogenic stopping cell for stopping energetic radioactive ions and extracting them as a low energy beam was developed. This first ever cryogenically operated stopping cell serves as prototype device for the Low-Energy Branch of the Super-FRS at FAIR. The cell has a stopping volume that is 1 m long and 25 cm in diameter. Ions are guided by a DC field along the length of the stopping cell and by a combined RF and DC fields provided by an RF carpet at the exit-hole side. The ultra-high purity of the stopping gas required for optimum ion survival is reached by cryogenic operation. The design considerations and construction of the cryogenic stopping cell, as well as some performance characteristics, are described in detail. Special attention is given to the cryogenic aspects in the design and construction of the stopping cell and the cryocooler-based cooling system. The cooling system allows the operation of the stopping cell at any desired temperature between about 70 K and room temperature. The cooling system performance in realistic on-line conditions at the FRS Ion Catcher Facility at GSI is discussed. A temperature of 110 K at which efficient ion survival was observed is obtained after 10 h of cooling. A minimum temperature of the stopping gas of 72 K was reached. The expertise gained from the design, construction and performance of the prototype cryogenic stopping cell has allowed the development of a final version for the Low-Energy Branch of the Super-FRS to proceed.

  2. Thermal Performance of Aged and Weathered Spray-On Foam Insulation (SOFI) Materials Under Cryogenic Vacuum Conditions (Cryostat-4)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The NASA Cryogenics Test Laboratory at Kennedy Space Center conducted long-term testing of SOFI materials under actual-use cryogenic conditions with Cryostat-4. The materials included in the testing were NCFI 24-124 (acreage foam), BX-265 (close-out foam, including intertank flange and bipod areas), and a potential alternate material, NCFI 27-68, (acreage foam with the flame retardant removed). Specimens of these materials were placed at two locations: a site that simulated aging (the Vehicle Assembly Building [VAB]) and a site that simulated weathering (the Atmospheric Exposure Test Site [beach site]). After aging/weathering intervals of 3, 6, and 12 months, the samples were retrieved and tested for their thermal performance under cryogenic vacuum conditions with test apparatus Cryostat-4.

  3. The Cryogenic Performances of Specific Optical and Electrical Components for a Liquid Argon Time Projection Chamber

    NASA Astrophysics Data System (ADS)

    Gong, Datao; Hou, Suen; Liu, Chonghan; Liu, Tiankuan; Su, Da-shung; Teng, Ping-kun; Xiang, Annie C.; Ye, Jingbo; LBNE Collaboration

    In this paper we present a cryogenic performance study of specific optical and electrical components for the Liquid Argon Time Projection Chamber (LArTPC), a potential far site detector technology of the long baseline neutrino experiment (LBNE). We have confirmed that an LVDS driver can drive a 20-meter CAT5E twisted pair up to 1 gigabit per second at liquid nitrogen temperature (77 K). We have verified that a 16:1 serializer Application Specific Integrated Circuit (ASIC), three types of laser diodes, optical fibers and connectors, and field-programming gate arrays (FPGAs) continue to function at 77 K. A variety of commercial resistors and capacitors have been tested at 77 K. All tests we have conducted show that the cold front-end electronics is promising.

  4. Design and performance of transfer assembly for the infrared telescope for Space Lab 2. [cryogenic system

    NASA Technical Reports Server (NTRS)

    Karr, G. R.; Hendricks, J. B.

    1984-01-01

    The cryogenic design features employed in the case of the Infrared Telescope (IRT) for Spacelab 2 are unique. They involve the delivery of helium gas at a temperature of 2 K to the IR detectors from a superfluid supply dewar which is separate from the telescope/detector unit. This design has the advantage that thermal and mechanical vibration disturbances in the liquid helium bath are decoupled from the IR detector. The interfacing of the storage dewar with the IRT telescope/detector unit (called cryostat) is the function of the subsystem which is called the transfer assembly (TA). The TA design is discussed, taking into account the porous plug module, the plumbing module, the helix module, and the dewar heat exchanger units. Aspects of transfer assembly performance are also considered.

  5. Integrated Two-Dimensional DRACO Simulations of Cryogenic DT Target Performance on OMEGA

    NASA Astrophysics Data System (ADS)

    Hu, S. X.; Radha, P. B.; Goncharov, V. N.; Betti, R.; Epstein, R.; Marshall, F. J.; McCrory, R. L.; Meyerhofer, D. D.; Sangster, T. C.; Skupsky, S.

    2013-10-01

    Integrated simulations of cryogenic deuterium-tritium (DT) target implosions on OMEGA have been performed using the radiation-hydrodynamic code DRACO. Taking into account the known nonuniformities of target and laser irradiation, 2-D simulations examine the target performance of a variety of ignition-relevant implosions. The effects of cross-beam energy transfer and nonlocal heat transport are mimicked by a time-dependent flux limiter. DRACO simulations show good agreement with experiments in ρR , neutron yield, Ti, neutron rate, and x-ray images for the mid-adiabat (α ~ 4 ) implosions. For low-adiabat (α ~ 2) and high in-flight aspect ratio (IFAR > 24) implosions, the integrated simulations with the known nonuniformity sources cannot fully explain the reduction in target performance. Examinations of other possible nonuniformity sources and the thermal conductivity model will be presented. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  6. A cryogenic test facility

    NASA Astrophysics Data System (ADS)

    Veenendaal, Ian

    The next generation, space-borne instruments for far infrared spectroscopy will utilize large diameter, cryogenically cooled telescopes in order to achieve unprecedented sensitivities. Low background, ground-based cryogenic facilities are required for the cryogenic testing of materials, components and subsystems. The Test Facility Cryostat (TFC) at the University of Lethbridge is a large volume, closed cycle, 4K cryogenic facility, developed for this purpose. This thesis discusses the design and performance of the facility and associated external instrumentation. An apparatus for measuring the thermal properties of materials is presented, and measurements of the thermal expansion and conductivity of carbon fibre reinforced polymers (CFRPs) at cryogenic temperatures are reported. Finally, I discuss the progress towards the design and fabrication of a demonstrator cryogenic, far infrared Fourier transform spectrometer.

  7. Large Cryogenic Germanium Detector. Final Report

    SciTech Connect

    Mandic, Vuk

    2013-02-13

    The goal of this project was to investigate possible ways of increasing the size of cryogenic Ge detectors. This project identified two possible approaches to increasing the individual cryogenic Ge detector size. The first approach relies on using the existing technology for growing detector-grade (high-purity) germanium crystals of dislocation density 100-7000 cm{sup -2}. The second approach is to consider dislocation-free Ge crystals.

  8. High-Performance Cryogenic Designs for OMEGA and the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Goncharov, V. N.; Collins, T. J. B.; Marozas, J. A.; Regan, S. P.; Betti, R.; Boehly, T. R.; Campbell, E. M.; Froula, D. H.; Igumenshchev, I. V.; McCrory, R. L.; Myatt, J. F.; Radha, P. B.; Sangster, T. C.; Shvydky, A.

    2016-10-01

    The main advantage of laser symmetric direct drive (SDD) is a significantly higher coupled drive laser energy to the hot-spot internal energy at stagnation compared to that of laser indirect drive. Because of coupling losses resulting from cross-beam energy transfer (CBET), however, reaching ignition conditions on the NIF with SDD requires designs with excessively large in-flight aspect ratios ( 30). Results of cryogenic implosions performed on OMEGA show that such designs are unstable to short-scale nonuniformity growth during shell implosion. Several CBET reduction strategies have been proposed in the past. This talk will discuss high-performing designs using several CBET-mitigation techniques, including using drive laser beams smaller than the target size and wavelength detuning. Designs that are predicted to reach alpha burning regimes as well as a gain of 10 to 40 at the NIF-scale will be presented. Hydrodynamically scaled OMEGA designs with similar CBET-reduction techniques will also be discussed. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  9. Experimental and numerical investigation on performance of a double inlet type cryogenic pulse tube refrigerator

    NASA Astrophysics Data System (ADS)

    Biswas, Animesh; Ghosh, Subrata K.

    2016-09-01

    A helium filled double inlet pulse tube refrigerator (DIPTR) has been designed, built and operated to provide cryogenic cooling. The experimental studies have been carried out to characterize the performance of the DIPTR at various values of the mean pressure of helium (0.7-1.5 MPa), amplitudes of pressure oscillations, and sizes of orifice opening. A detailed time-dependent three dimensional computational fluid dynamics (CFD) model of the DIPTR has also been developed to predict its performance. In the CFD model, the continuity, momentum and energy equations have been solved for both the refrigerant gas (helium) and the porous media regions (the regenerator and heat exchangers) in the DIPTR. The computational results have been compared with specific experimental results to validate the numerical model. The results predicted by the model show better results as compared to experimental results, as the effects of wall thicknesses and natural convective losses of the various components of the DIPTR to the surroundings have not been included in the model.

  10. On the Relationship Between Schottky Barrier Capacitance and Mixer Performance at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    1996-01-01

    The flat-band voltage is the Schottky junction voltage required to shrink the depletion width to zero. At cryogenic temperatures, mixer diodes are generally biased and/or pumped beyond the flat-band condition to minimize conversion loss and noise figure. This occurs despite the presumed sharp increase in junction capacitance near flat-band, which should instead limit mixer performance. Past moderate forward bias, the diode C-V relationship is difficult to measure. A simple analytic expression for C(V) is usually used to model and predict mixer performance. This letter provides experimental data on C(V) at 77 K based on a microwave measurement and modeling technique. Data is also provided on the conversion loss of a singly balanced mixer optimized for 77 K operation. The connection between junction capacitance, flat-band potential, and conversion loss is examined. It is shown that the analytic expression greatly overestimates the junction capacitance that occurs as flat-band is approached.

  11. Performance test of the cryogenic cooling system for the superconducting fault current limiter

    NASA Astrophysics Data System (ADS)

    Hong, Yong-Ju; In, Sehwan; Yeom, Han-Kil; Kim, Heesun; Kim, Hye-Rim

    2015-12-01

    A Superconducting Fault Current Limiter is an electric power device which limits the fault current immediately in a power grid. The SFCL must be cooled to below the critical temperature of high temperature superconductor modules. In general, they are submerged in sub-cooled liquid nitrogen for their stable thermal characteristics. To cool and maintain the target temperature and pressure of the sub-cooled liquid nitrogen, the cryogenic cooling system should be designed well with a cryocooler and coolant circulation devices. The pressure of the cryostat for the SFCL should be pressurized to suppress the generation of nitrogen bubbles in quench mode of the SFCL. In this study, we tested the performance of the cooling system for the prototype 154 kV SFCL, which consist of a Stirling cryocooler, a subcooling cryostat, a pressure builder and a main cryostat for the SFCL module, to verify the design of the cooling system and the electric performance of the SFCL. The normal operation condition of the main cryostat is 71 K and 500 kPa. This paper presents tests results of the overall cooling system.

  12. The measurement of thermodynamic performance in cryogenic two-phase turbo-expander

    NASA Astrophysics Data System (ADS)

    Niu, Lu; Hou, Yu; Sun, Wan; Chen, Shuangtao

    2015-09-01

    Liquid fraction measurement in cryogenic two-phase flow is a complex issue, especially for an industrial cryogenic system. In this paper, a simple thermal method is proposed for measuring the liquid fraction in cryogenic two-phase turbo-expander by an electric heating unit in experimental study. The liquid fraction of the cryogenic two-phase flow is determined through the heat balance built at the outlet of the turbo-expander (inlet of heating unit) and the outlet of the heating unit. Liquid fractions from 1.16% to 5.02% are obtained from five two-phase expansion cases. Under the same turbo-expander inlet pressure and rotating speed, five superheated expansion cases are tested to evaluate the wetness loss in two-phase expansion. The results show that the proposed method is successful in measuring the liquid fraction of cryogenic two-phase expansion for turbo-expander in an industrial air separation plant. The experimental isentropic efficiency ratio and the tested Baumann factor decrease with the increasing mean wetness. Based on prediction of Baumann rule, the cryogenic turbo-expander with low liquid fraction in two-phase expansion cases suffers from more severe wetness loss than that with the higher liquid fraction.

  13. Initial observations of GeSe-xenon transport experiments performed on the D1 space flight

    NASA Technical Reports Server (NTRS)

    Wiedemeier, H.; Trivedi, S. B.

    1986-01-01

    GeSe-xenon experiments performed aboard the D1 mission at xenon pressures of 2 and 6 atm confirm the crystal growth pattern, sizes, and surface morphology of crystals previously grown aboard STS-7 for different pressures. Besides the deposition and growth of GeSe crystals on the ampoule wall, several large single-crystalline GeSe platelets with lateral dimensions much greater than those of crystals on the wall and obtained on the ground are found. The present results reemphasize the question concerning the nucleation phenomena in microgravity.

  14. Ambient and Cryogenic Alignment Verification and Performance of the Infrared Multi-Object Spectrometer

    NASA Technical Reports Server (NTRS)

    Connelly, Joseph A.; Ohl, Raymond G.; Mink, Ronald G.; Mentzell, J. Eric; Saha, Timo T.; Tveekrem, June L.; Hylan, Jason E.; Sparr, Leroy M.; Chambers, V. John; Hagopian, John G.

    2003-01-01

    The Infrared Multi-Object Spectrometer (IRMOS) is a facility instrument for the Kitt Peak National Observatory 4 and 2.1 meter telescopes. IRMOS is a near-IR (0.8 - 2.5 micron) spectrometer with low- to mid-resolving power (R = 300 - 3000). IRMOS produces simultaneous spectra of approximately 100 objects in its 2.8 x 2.0 arc-min field of view using a commercial Micro Electro-Mechanical Systems (MEMS) Digital Micro-mirror Device (DMD) from Texas Instruments. The IRMOS optical design consists of two imaging subsystems. The focal reducer images the focal plane of the telescope onto the DMD field stop, and the spectrograph images the DMD onto the detector. We describe ambient breadboard subsystem alignment and imaging performance of each stage independently, and the ambient and cryogenic imaging performance of the fully assembled instrument. Interferometric measurements of subsystem wavefront error serve to venfy alignment, and are accomplished using a commercial, modified Twyman-Green laser unequal path interferometer. Image testing provides further verification of the optomechanical alignment method and a measurement of near-angle scattered light due to mirror small-scale surface error. Image testing is performed at multiple field points. A mercury-argon pencil lamp provides spectral lines at 546.1 nm and 1550 nm, and a CCD camera and IR camera are used as detectors. We use commercial optical modeling software to predict the point-spread function and its effect on instrument slit transmission and resolution. Our breadboard test results validate this prediction. We conclude with an instrument performance prediction for first light.

  15. Development and performance validation of a cryogenic linear stage for SPICA-SAFARI verification

    NASA Astrophysics Data System (ADS)

    Ferrari, Lorenza; Smit, H. P.; Eggens, M.; Keizer, G.; de Jonge, A. W.; Detrain, A.; de Jonge, C.; Laauwen, W. M.; Dieleman, P.

    2014-07-01

    In the context of the SAFARI instrument (SpicA FAR-infrared Instrument) SRON is developing a test environment to verify the SAFARI performance. The characterization of the detector focal plane will be performed with a backilluminated pinhole over a reimaged SAFARI focal plane by an XYZ scanning mechanism that consists of three linear stages stacked together. In order to reduce background radiation that can couple into the high sensitivity cryogenic detectors (goal NEP of 2•10-19 W/√Hz and saturation power of few femtoWatts) the scanner is mounted inside the cryostat in the 4K environment. The required readout accuracy is 3 μm and reproducibility of 1 μm along the total travel of 32 mm. The stage will be operated in "on the fly" mode to prevent vibrations of the scanner mechanism and will move with a constant speed varying from 60 μm/s to 400 μm/s. In order to meet the requirements of large stroke, low dissipation (low friction) and high accuracy a DC motor plus spindle stage solution has been chosen. In this paper we will present the stage design and stage characterization, describing also the measurements setup. The room temperature performance has been measured with a 3D measuring machine cross calibrated with a laser interferometer and a 2-axis tilt sensor. The low temperature verification has been performed in a wet 4K cryostat using a laser interferometer for measuring the linear displacements and a theodolite for measuring the angular displacements. The angular displacements can be calibrated with a precision of 4 arcsec and the position could be determined with high accuracy. The presence of friction caused higher values of torque than predicted and consequently higher dissipation. The thermal model of the stage has also been verified at 4K.

  16. Performance of High-frequency High-flux Magnetic Cores at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Gerber, Scott S.; Hammoud, Ahmad; Elbuluk, Malik E.; Patterson, Richard L.

    2002-01-01

    Three magnetic powder cores and one ferrite core, which are commonly used in inductor and transformer design for switch mode power supplies, were selected for investigation at cryogenic temperatures. The powder cores are Molypermalloy Core (MPC), High Flux Core (HFC), and Kool Mu Core (KMC). The performance of four inductors utilizing these cores has been evaluated as a function of temperature from 20 C to -180 C. All cores were wound with the same wire type and gauge to obtain equal values of inductance at room temperature. Each inductor was evaluated in terms of its inductance, quality (Q) factor, resistance, and dynamic hysteresis characteristics (B-H loop) as a function of temperature and frequency. Both sinusoidal and square wave excitations were used in these investigations. Measured data obtained on the inductance showed that both the MPC and the HFC cores maintain a constant inductance value, whereas with the KMC and ferrite core hold a steady value in inductance with frequency but decrease as temperature is decreased. All cores exhibited dependency, with varying degrees, in their quality factor and resistance on test frequency and temperature. Except for the ferrite, all cores exhibited good stability in the investigated properties with temperature as well as frequency. Details of the experimental procedures and test results are presented and discussed in the paper.

  17. Hubble Space Telescope Pointing Performance Due to Micro-Dynamic Disturbances from the NICMOS Cryogenic Cooler

    NASA Technical Reports Server (NTRS)

    Clapp, Brian R.; Sills, Joel W., Jr.; Voorhees, Carl R.; Griffin, Thomas J. (Technical Monitor)

    2002-01-01

    The Vibration Admittance Test (VET) was performed to measure the emitted disturbances of the Near Infrared Camera and Multi-Object Spectrometer (NICMOS) Cryogenic Cooler (NCC) in preparation for NCC installation onboard the Hubble Space Telescope (HST) during Servicing Mission 3B (SM3B). Details of the VET ground-test are described, including facility characteristics, sensor complement and configuration, NCC suspension, and background noise measurements. Kinematic equations used to compute NCC mass center displacements and accelerations from raw measurements are presented, and dynamic equations of motion for the NCC VET system are developed and verified using modal test data. A MIMO linear frequency-domain analysis method is used to compute NCC-induced loads and HST boresight jitter from VET measurements. These results are verified by a nonlinear time-domain analysis approach using a high-fidelity structural dynamics and pointing control simulation for HST. NCC emitted acceleration levels not exceeding 35 micro-g rms were measured in the VET and analysis methods herein predict 3.1 milli-areseconds rms jitter for HST on-orbit. Because the NCC is predicted to become the predominant disturbance source for HST, VET results indicate that HST will continue to meet the 7 milli-arcsecond pointing stability mission requirement in the post-SM3B era.

  18. Cryogenic System for J-Parc Neutrino Superconducting Magnet Beam LINE—DESIGN, Construction and Performance Test

    NASA Astrophysics Data System (ADS)

    Makida, Y.; Ohhata, H.; Okamura, T.; Suzuki, S.; Araoka, O.; Ogitsu, T.; Kimura, N.; Nakamoto, T.; Sasaki, K.; Kaneda, S.; Takahashi, T.; Ito, A.; Nagami, M.; Kumaki, T.; Nakashima, T.

    2010-04-01

    A helium cryogenic plant has been constructed in the proton accelerator research complex, J-PARC, to cool a string of superconducting magnets in the neutrino beam line since 2005. It consists of a screw compressor with a capacity of 160 g/s at 1.4 MPa, a 1.5 kW refrigerator, a centrifugal SHE pump with a flow rate of 300 g/s and peripherals. After system integration, performance tests have been carried out. In a preliminary cooling test without magnets, the cryogenic system attained a cooling capacity of 522 W by circulating supercritical helium flow of 300 g/s at 0.4 MPa and at 4.5 K. Afterwards a full system test with the magnets was carried out. The magnets were successfully charged up to an ultimate current of 5000 A beyond a nominal current of 4400 A. This paper describes the plant design and the result of performance measurements.

  19. Fundamentals of Cryogenics

    NASA Technical Reports Server (NTRS)

    Johnson, Wesley; Tomsik, Thomas; Moder, Jeff

    2014-01-01

    Analysis of the extreme conditions that are encountered in cryogenic systems requires the most effort out of analysts and engineers. Due to the costs and complexity associated with the extremely cold temperatures involved, testing is sometimes minimized and extra analysis is often relied upon. This short course is designed as an introduction to cryogenic engineering and analysis, and it is intended to introduce the basic concepts related to cryogenic analysis and testing as well as help the analyst understand the impacts of various requests on a test facility. Discussion will revolve around operational functions often found in cryogenic systems, hardware for both tests and facilities, and what design or modelling tools are available for performing the analysis. Emphasis will be placed on what scenarios to use what hardware or the analysis tools to get the desired results. The class will provide a review of first principles, engineering practices, and those relations directly applicable to this subject including such topics as cryogenic fluids, thermodynamics and heat transfer, material properties at low temperature, insulation, cryogenic equipment, instrumentation, refrigeration, testing of cryogenic systems, cryogenics safety and typical thermal and fluid analysis used by the engineer. The class will provide references for further learning on various topics in cryogenics for those who want to dive deeper into the subject or have encountered specific problems.

  20. Testing the performance of a cryogenic visualization system on thermal counterflow by using hydrogen and deuterium solid tracers.

    PubMed

    La Mantia, M; Chagovets, T V; Rotter, M; Skrbek, L

    2012-05-01

    An experimental apparatus has been designed to analyze by visualization cryogenic flows of liquid (4)He and consequently address unresolved problems of quantum turbulence. The newly implemented flow visualization setup is described and its specific features discussed. Thermal counterflow experiments have been performed and the motion of solid hydrogen and deuterium tracers studied by using the particle tracking velocimetry technique in order to probe the system capabilities. It is shown that the obtained results are consistent with the two-fluid model describing the behavior of superfluid (4)He. A number of technical and fundamental issues, such as particles' aggregation, role of rotating particles in counterflow and evidence of non-Gaussian distribution of tracers' velocities, are also discussed. The apparatus appears to be well-suited to the task of analyzing cryogenic flows and potentially capable of obtaining new results stimulating further understanding of the underlying physics.

  1. The challenges of archiving networked-based multimedia performances (Performance cryogenics)

    NASA Astrophysics Data System (ADS)

    Cohen, Elizabeth; Cooperstock, Jeremy; Kyriakakis, Chris

    2002-11-01

    Music archives and libraries have cultural preservation at the core of their charters. New forms of art often race ahead of the preservation infrastructure. The ability to stream multiple synchronized ultra-low latency streams of audio and video across a continent for a distributed interactive performance such as music and dance with high-definition video and multichannel audio raises a series of challenges for the architects of digital libraries and those responsible for cultural preservation. The archiving of such performances presents numerous challenges that go beyond simply recording each stream. Case studies of storage and subsequent retrieval issues for Internet2 collaborative performances are discussed. The development of shared reality and immersive environments generate issues about, What constitutes an archived performance that occurs across a network (in multiple spaces over time)? What are the families of necessary metadata to reconstruct this virtual world in another venue or era? For example, if the network exhibited changes in latency the performers most likely adapted. In a future recreation, the latency will most likely be completely different. We discuss the parameters of immersive environment acquisition and rendering, network architectures, software architecture, musical/choreographic scores, and environmental acoustics that must be considered to address this problem.

  2. Assessment of DC and low-frequency noise performances of triple-gate FinFETs at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Cretu, B.; Boudier, D.; Simoen, E.; Veloso, A.; Collaert, N.

    2016-12-01

    In this work an in-depth investigation in terms of short-channel effects, analog operation and low-frequency noise performances at very low temperature operation is given. The most important electrical parameters are investigated and it is highlighted that for our devices the downscaling to sub-10 nm technologies leads to improved drain-induced barrier lowering (DIBL) and intrinsic voltage gain. As expected, cryogenic operation leads to an amelioration of the subthreshold slope and charge sharing effect. A reduction of the threshold voltage and of the effective mobility is also observed. Discontinuities in the subthreshold slope in the drain current-gate voltage characteristics can be linked to potential non-uniformities in the channel width. It was observed that noise spectra contain 1/f and generation-recombination contributions. Low-frequency noise measurements as a function of the applied gate voltage at cryogenic operation show that the carrier number fluctuations dominate the flicker noise in weak inversion. Access resistance noise contributions were evidenced in strong inversion. The fact that devices suffer from generation-recombination noise even at 10 K operation shows that there are some active traps even at this cryogenic temperature operation. The low-frequency noise measurements as a function of temperature (10 K-70 K) are used as a non-destructive device characterization tool in order to identify traps induced during the device processing and to make a correlation between the observed traps and some technological steps.

  3. Cryogenic Information Center

    NASA Technical Reports Server (NTRS)

    Mohling, Robert A.; Marquardt, Eric D.; Fusilier, Fred C.; Fesmire, James E.

    2003-01-01

    The Cryogenic Information Center (CIC) is a not-for-profit corporation dedicated to preserving and distributing cryogenic information to government, industry, and academia. The heart of the CIC is a uniform source of cryogenic data including analyses, design, materials and processes, and test information traceable back to the Cryogenic Data Center of the former National Bureau of Standards. The electronic database is a national treasure containing over 146,000 specific bibliographic citations of cryogenic literature and thermophysical property data dating back to 1829. A new technical/bibliographic inquiry service can perform searches and technical analyses. The Cryogenic Material Properties (CMP) Program consists of computer codes using empirical equations to determine thermophysical material properties with emphasis on the 4-300K range. CMP's objective is to develop a user-friendly standard material property database using the best available data so government and industry can conduct more accurate analyses. The CIC serves to benefit researchers, engineers, and technologists in cryogenics and cryogenic engineering, whether they are new or experienced in the field.

  4. Cryogenic Insulation Systems

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, J. E.; Wikstrom, J. P.

    1999-01-01

    The results of a comparative study of cryogenic insulation systems performed are presented. The key aspects of thermal insulation relative to cryogenic system design, testing, manufacturing, and maintenance are discussed. An overview of insulation development from an energy conservation perspective is given. Conventional insulation materials for cryogenic applications provide three levels of thermal conductivity. Actual thermal performance of standard multilayer insulation (MLI) is several times less than laboratory performance and often 10 times worse than ideal performance. The cost-effectiveness of the insulation system depends on thermal performance; flexibility and durability; ease of use in handling, installation, and maintenance; and overall cost including operations, maintenance, and life cycle. Results of comprehensive testing of both conventional and novel materials such as aerogel composites using cryostat boil-off methods are given. The development of efficient, robust cryogenic insulation systems that operate at a soft vacuum level is the primary focus of this paper.

  5. Performance of the primary mirror center-of-curvature optical metrology system during cryogenic testing of the JWST Pathfinder telescope

    NASA Astrophysics Data System (ADS)

    Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

    2016-07-01

    The James Webb Space Telescope (JWST) primary mirror (PM) is 6.6 m in diameter and consists of 18 hexagonal segments, each 1.5 m point-to-point. Each segment has a six degree-of-freedom hexapod actuation system and a radius of-curvature (RoC) actuation system. The full telescope will be tested at its cryogenic operating temperature at Johnson Space Center. This testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The COCOA includes an interferometer, a reflective null, an interferometer-null calibration system, coarse and fine alignment systems, and two displacement measuring interferometer systems. A multiple-wavelength interferometer (MWIF) is used for alignment and phasing of the PM segments. The ADMA is used to measure, and set, the spacing between the PM and the focus of the COCOA null (i.e. the PM center-of-curvature) for determination of the ROC. The performance of these metrology systems was assessed during two cryogenic tests at JSC. This testing was performed using the JWST Pathfinder telescope, consisting mostly of engineering development and spare hardware. The Pathfinder PM consists of two spare segments. These tests provided the opportunity to assess how well the center-of-curvature optical metrology hardware, along with the software and procedures, performed using real JWST telescope hardware. This paper will describe the test setup, the testing performed, and the resulting metrology system performance. The knowledge gained and the lessons learned during this testing will be of great benefit to the accurate and efficient cryogenic testing of the JWST flight telescope.

  6. Performance of the Primary Mirror Center-of-curvature Optical Metrology System During Cryogenic Testing of the JWST Pathfinder Telescope

    NASA Technical Reports Server (NTRS)

    Hadaway, James B.; Wells, Conrad; Olczak, Gene; Waldman, Mark; Whitman, Tony; Cosentino, Joseph; Connolly, Mark; Chaney, David; Telfer, Randal

    2016-01-01

    The James Webb Space Telescope (JWST) primary mirror (PM) is 6.6 m in diameter and consists of 18 hexagonal segments, each 1.5 m point-to-point. Each segment has a six degree-of-freedom hexapod actuation system and a radius-of-curvature (RoC) actuation system. The full telescope will be tested at its cryogenic operating temperature at Johnson Space Center. This testing will include center-of-curvature measurements of the PM, using the Center-of-Curvature Optical Assembly (COCOA) and the Absolute Distance Meter Assembly (ADMA). The COCOA includes an interferometer, a reflective null, an interferometer-null calibration system, coarse & fine alignment systems, and two displacement measuring interferometer systems. A multiple-wavelength interferometer (MWIF) is used for alignment & phasing of the PM segments. The ADMA is used to measure, and set, the spacing between the PM and the focus of the COCOA null (i.e. the PM center-of-curvature) for determination of the ROC. The performance of these metrology systems was assessed during two cryogenic tests at JSC. This testing was performed using the JWST Pathfinder telescope, consisting mostly of engineering development & spare hardware. The Pathfinder PM consists of two spare segments. These tests provided the opportunity to assess how well the center-of-curvature optical metrology hardware, along with the software & procedures, performed using real JWST telescope hardware. This paper will describe the test setup, the testing performed, and the resulting metrology system performance. The knowledge gained and the lessons learned during this testing will be of great benefit to the accurate & efficient cryogenic testing of the JWST flight telescope.

  7. Cryogenics Research and Engineering Experience

    NASA Technical Reports Server (NTRS)

    Toro Medina, Jaime A.

    2013-01-01

    Energy efficient storage, transfer and use of cryogens and cryogenic propellants on Earth and in space have a direct impact on NASA, government and commercial programs. Research and development on thermal insulation, propellant servicing, cryogenic components, material properties and sensing technologies provides industry, government and research institutions with the cross-cutting technologies to manage low-temperature applications. Under the direction of the Cryogenic Testing Lab at Kennedy Space Center, the work experience acquired allowed me to perform research, testing, design and analysis of current and future cryogenic technologies to be applied in several projects.

  8. Performance test of pipe-shaped radiation shields for cryogenic interferometric gravitational wave detectors

    NASA Astrophysics Data System (ADS)

    Sakakibara, Yusuke; Kimura, Nobuhiro; Akutsu, Tomotada; Suzuki, Toshikazu; Kuroda, Kazuaki

    2015-08-01

    One of the most important challenges in cryogenic interferometric gravitational wave detectors is to reduce the undesirable thermal radiation coming through holes in the radiation shield, which are necessary for the laser beam to pass through. For this purpose, pipe-shaped radiation shields called duct shields are used. Here, we have manufactured duct shields for KAGRA in Japan, one of the cryogenic interferometric gravitational wave detectors, and measured the thermal radiation coming through the duct shields. The measured result was found to be consistent with the calculation result that the duct shield can reduce the thermal radiation to less than 1%. This fact confirmed that the amount of thermal radiation coming through the duct shields was smaller than KAGRA’s requirement.

  9. Effect of trailing edge thickness on the performance of a helium turboexpander used in cryogenic refrigeration and liquefaction cycles

    NASA Astrophysics Data System (ADS)

    Sam, Ashish Alex; Ghosh, Parthasarathi

    2017-02-01

    Turboexpanders in cryogenic refrigeration and liquefaction cycles, which is of radial inflow configuration, constitute stationary and rotating components like nozzle, a rotating wheel and a diffuser. The relative motion between the stationary and rotating components and the interactions of secondary flows and vortices at different stages make the turboexpander flow unsteady. Computational Fluid Dynamics (CFD) analysis of this flow is essential to identify the scope for improvement in efficiency. The trailing edge vortex formed due to the mixing of the pressure and suction side streams is an important phenomenon to analyse, as this leads to efficiency degradation of the machine. Additionally, there are mechanical vibrations and dynamic loading associated with. This flow non-uniformity at the exit should be suppressed as this may affect the pressure recovery process in the diffuser and thereby the turboexpander’s performance. The strength of this vortex depends upon the geometrical parameters like trailing edge shape, thickness etc. In this paper, transient CFD analyses of a cryogenic turboexpander designed for helium refrigeration and liquefaction cycles using Ansys CFX® were performed to investigate the effect of trailing edge thickness on the turboexpander performance and the performance characteristics and the flow patterns were compared to understand the flow characteristics in each case.

  10. Quantum dot Ge/TiO2 heterojunction photoconductor fabrication and performance

    NASA Astrophysics Data System (ADS)

    Church, Carena P.; Muthuswamy, Elayaraja; Zhai, Guangmei; Kauzlarich, Susan M.; Carter, Sue A.

    2013-11-01

    Spun cast TiO2-Ge quantum dot (QD) heterojunction type photodetectors have been fabricated and characterized, with interest paid to photocurrent enhancements related to device design. Performance as a function of absorber layer thickness, QD size, and back contact is investigated. We have achieved ultra-thin (˜200 nm) devices with photocurrents at 0.5 V of 10-4 A cm-2 while the thickest devices have photocurrents at 0.5 V of 10-2 A cm-2 with on-off ratios >100, which represents 5 orders of magnitude increase in photocurrents over previously fabricated Ge QD devices. At 0.5 V bias, the currents in our devices are competitive with thin-film Ge photovoltaics.

  11. Ultra low noise cryogenic amplifiers for radio astronomy

    NASA Astrophysics Data System (ADS)

    Bryerton, E. W.; Morgan, Matthew Alexander; Pospieszalski, Marian W.

    2013-01-01

    Cryogenic cooling of receivers to reduce their noise temperature is especially important in radio astronomy, as the antenna noise temperature is determined by the cosmic microwave background radiation (2.725 K) modified by the presence of atmosphere. For frequencies up to 120 GHz direct amplification at cryogenic temperatures is typically employed using InP heterostructure field-effect transistors (HFETs) or, more recently, SiGe heterostructure bipolar transistors (HBTs). This article reviews developments in this field and presents the current state-of-the-art. Examples of noise performance of amplifiers using InP HFETs and SiGe HBTs are compared with the model predications. Some gaps in our current understanding of experimental results are emphasized, and some comments on possible future developments are offered.

  12. Optimum performance analysis of an irreversible quantum cryogenic refrigeration cycle working with an ideal Bose or Fermi gas

    NASA Astrophysics Data System (ADS)

    Lin, Bihong; Chen, Jincan

    2008-05-01

    An irreversible model of the Carnot cryogenic refrigeration cycle working with an ideal Bose or Fermi gas is established, which is composed of two irreversible adiabatic and two isothermal processes. The effects of the quantum degeneracy of the working substance, the irreversibility of the finite-rate heat transfer between the working fluid and the heat reservoirs, and the internal irreversibility in two adiabatic processes on the optimum performance characteristics of the quantum refrigeration cycle are analyzed. The performance characteristics of the cycle in strong and weak gas degeneracy cases are discussed. Expressions for several important performance parameters such as the coefficient of performance, cooling rate and power input are derived. By using numerical solutions, the cooling rate of the cycle is optimized for a given power input. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal regions of the coefficient of performance and power input are determined. Some optimum criteria are given.

  13. Parametric performance of circumferentially grooved heat pipes with homogeneous and graded-porosity slab wicks at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Groll, M.; Pittman, R. B.; Eninger, J. E.

    1975-01-01

    A recently developed, potentially high-performance nonarterial wick has been extensively tested. This slab wick has an axially varying porosity which can be tailored to match the local stress imposed on the wick. The purpose of the tests was to establish the usefulness of the graded-porosity slab wick at cryogenic temperatures between 110 K and 260 K, with methane and ethane as working fluids. For comparison, a homogeneous (i.e., uniform porosity) slab wick was also tested. The tests included: (1) maximum heat pipe performance as a function of fluid inventory, (2) maximum performance as a function of operating temperature, (3) maximum performance as a function of evaporator elevation, and (4) influence of slab wick orientation on performance. The experimental data was compared with theoretical predictions obtained with the computer program GRADE.

  14. Development of an improved performance SiGe unicouple

    SciTech Connect

    Nakahara, J.F.; Franklin, B.; DeFillipo, L.E.

    1995-01-20

    A two-step diffusion bonding process was developed such that the p-type material is bonded to the SiMo hot shoe first at 1594 K followed by the lower melting point n-type material between 1518 and 1520 K. Standard procedures were used to silicon nitride coat the thermoelectric pellets and to attach the cold side CTE transition and heat rejection components to produce unicouples. Two unicouples successfully withstood simulated rivet operations as would be experienced in the fabrication of a Radioisotope Thermoelectric Generator (RTG) converter to verify the integrity of the tungsten cold shoe to thermoelectric material interface. The performance of these unicouples will be further evaluated in an 18-couple test module. {copyright}American Institute of Physics 1995

  15. Cryogenic exciter

    DOEpatents

    Bray, James William [Niskayuna, NY; Garces, Luis Jose [Niskayuna, NY

    2012-03-13

    The disclosed technology is a cryogenic static exciter. The cryogenic static exciter is connected to a synchronous electric machine that has a field winding. The synchronous electric machine is cooled via a refrigerator or cryogen like liquid nitrogen. The static exciter is in communication with the field winding and is operating at ambient temperature. The static exciter receives cooling from a refrigerator or cryogen source, which may also service the synchronous machine, to selected areas of the static exciter and the cooling selectively reduces the operating temperature of the selected areas of the static exciter.

  16. SRF CAVITY PERFORMANCE OVERVIEW FOR THE 12 GeV UPGRADE

    SciTech Connect

    A. Burrill, G.K. Davis, C.E. Reece, A.V. Reilly, M. Stirbet

    2012-07-01

    The CEBAF accelerator, a recirculating CW electron accelerator that is currently operating at Jefferson Laboratory, is in the process of having 10 new cryomodules installed to allow for the maximum beam energy to be increased from 6 GeV to 12 GeV. This upgrade required the fabrication, processing and RF qualification of 80, seven cell elliptical SRF cavities, a process that was completed in February 2012. The RF performance achieve in the vertical testing dewars has exceeded the design specification by {approx}25% and is a testament to the cavity design and processing cycle that has been implemented. This paper will provide a summary of the cavity RF performance in the vertical tests, as well as review the overall cavity processing cycle and duration for the project.

  17. Design and performance of a modular low-radioactivity readout system for cryogenic detectors in the CDMS experiment

    NASA Astrophysics Data System (ADS)

    Akerib, D. S.; Barnes, P. D., Jr.; Brink, P. L.; Cabrera, B.; Clarke, R. M.; Gaitskell, R. J.; Golwala, S. R.; Huber, M. E.; Kurylowicz, M.; Mandic, V.; Martinis, J. M.; Meunier, P.; Mirabolfathi, N.; Nam, S. W.; Perillo-Isaac, M.; Saab, T.; Sadoulet, B.; Schnee, R. W.; Seitz, D. N.; Shutt, T.; Smith, G. W.; Stockwell, W. K.; Sundqvist, K. M.; White, S.

    2008-07-01

    The Cryogenic Dark Matter Search (CDMS) experiment employs ultra-cold solid-state detectors to search for rare events resulting from WIMP-nucleus scattering. An innovative detector packaging and readout system has been developed to meet the unusual combination of requirements for: low temperature, low radioactivity, low energy threshold, and large channel count. Features include use of materials with low radioactivity such as multi-layer KAPTON laminates for circuit boards; immunity to microphonic noise via a vacuum coaxial wiring design, manufacturability, and modularity. The detector readout design had to accommodate various electronic components which have to be operated in close proximity to the detector as well maintaining separate individual temperatures (ranging from 600 mK to 150 K) in order to achieve optimal noise performance. The paper will describe the general electrical, thermal, and mechanical designs of the CDMS readout system, as well as presenting the theoretical and measured performance of the detector readout channels.

  18. Performances Of Arrays Of Ge:Ga Far-Infrared Detectors

    NASA Technical Reports Server (NTRS)

    Mccreight, C.; Farhoomand, J.

    1992-01-01

    Report presents evaluation of performances of two electronic modules containing few-element linear focal-plane arrays of Ge:Ga photodetectors and associated multiplexing readout circuitry. Tested to demonstrate feasibility of many-element, two-dimensional focal-plane arrays of far-infrared detectors and associated circuitry for use in astronomical and other low-background scientific observations. Revealed deficiencies that must be overcome in future designs.

  19. Thermal performance of a modularized replaceable multilayer insulation system for a cryogenic stage

    NASA Technical Reports Server (NTRS)

    Knoll, R. H.

    1977-01-01

    A rugged modularized MLI system for a 2.23-meter-diameter (87.6-in.-diam) liquid hydrogen tank was designed, fabricated, and tested under simulated near-earth and deep-space environments. The two blankets of the system were each composed of 17 double-aluminized Mylar radiation shields separated by silk net. The unit area weight of the installed system was 1.54 kg/sqm (0.32 lb/sq ft). The overall average heat transferred into the insulated tank was 22.7 and 0.98 watts (77.4 and 3.3 Btu/hr) during simulated near-earth and deep-space testing, respectively. The near-earth result was only 2.6 times that predicted for an undisturbed insulation system (i.e., no seams or penetrations). Tests indicate that this insulation concept could be useful for a cryogenic space tug or orbit transfer vehicle application.

  20. Model predictions and observed performance of JWST's cryogenic position metrology system

    NASA Astrophysics Data System (ADS)

    Lunt, Sharon R.; Rhodes, David; DiAntonio, Andrew; Boland, John; Wells, Conrad; Gigliotti, Trevis; Johanning, Gary

    2016-07-01

    The James Webb Space Telescope (JWST) cryogenic testing requires measurement systems that both obtain a very high degree of accuracy and can function in that environment. Close-range photogrammetry was identified as meeting those criteria. Testing the capability of a close-range photogrammetric system prior to its existence is a challenging problem. Computer simulation was chosen over building a scaled mock-up to allow for increased flexibility in testing various configurations. Extensive validation work was done to ensure that the actual as-built system meets accuracy and repeatability requirements. The simulated image data predicted the uncertainty in measurement to be within specification and this prediction was borne out experimentally. Uncertainty at all levels was verified experimentally to be <0.1 mm.

  1. Model Predictions and Observed Performance of JWST's Cryogenic Position Metrology System

    NASA Technical Reports Server (NTRS)

    Lunt, Sharon R.; Rhodes, David; DiAntonio, Andrew; Boland, John; Wells, Conrad; Gigliotti, Trevis; Johanning, Gary

    2016-01-01

    The James Webb Space Telescope cryogenic testing requires measurement systems that both obtain a very high degree of accuracy and can function in that environment. Close-range photogrammetry was identified as meeting those criteria. Testing the capability of a close-range photogrammetric system prior to its existence is a challenging problem. Computer simulation was chosen over building a scaled mock-up to allow for increased flexibility in testing various configurations. Extensive validation work was done to ensure that the actual as-built system meet accuracy and repeatability requirements. The simulated image data predicted the uncertainty in measurement to be within specification and this prediction was borne out experimentally. Uncertainty at all levels was verified experimentally to be less than 0.1 millimeters.

  2. Cryogenic System for Interferometry of High-precision Optics at 20 K: Design and Performance

    NASA Technical Reports Server (NTRS)

    Blake,Peter; Chambers, John; Mink, Ronald G.; Content, David; Davila, Pamela; Robinson, F. David; Chrzanowski, Chris; Shirgur, Badri; Frohlich, chip

    2005-01-01

    This report describes the facility and experimental methods at the Goddard Space Flight Center Optics Branch for the measurement of the surface figure of cryogenically-cooled spherical mirrors using standard phase-shifting interferometry, with a standard uncertainty below 2nm rms. Two developmental silicon carbide mirrors were tested: both were spheres with radius of curvature of 600 mm, and clear apertures of 150 mm. The mirrors were cooled within a cryostat, and the surface figure error measured through a fused-silica window. The GSFC team developed methods to measure the in-situ SFE at 20 K with a combined standard uncertainty below 2 nm rms and the change in SFE with temperature (the cryochange) with a combined standard uncertainty of 0.25 -- 0.75 nm rms. This paper will present the measurement facility, methods, and uncertainty analysis.

  3. Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

    NASA Technical Reports Server (NTRS)

    Salerno, L. J.; Kittel, P. L.; Spivak, A. L.

    1991-01-01

    Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (nine cycles at 4.2K) and superfluid helium temperature (four cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10 exp -9 std cu cm/s, during testing.

  4. Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

    NASA Technical Reports Server (NTRS)

    Salerno, Louis J.; Kittel, Peter; Spivak, Alan L.

    1989-01-01

    Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm, and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (9 cycles at 4.2 K), and superfluid helium temperature (4 cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak-rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10(-9) std-cc/sec, during testing.

  5. Performance of all-metal demountable cryogenic seals at superfluid helium temperatures

    NASA Technical Reports Server (NTRS)

    Salerno, Louis J.; Spivak, Alan L.; Kittel, Peter

    1989-01-01

    Two all-metal demountable cryogenic seals with an outside diameter of 36.6 mm, inside diameter of 27.2 mm, and thickness of 0.51 mm were leak-tested at room temperature (300 K), liquid nitrogen temperature (21 cycles at 77 K), liquid helium temperature (9 cycles at 4.2 K), and susperfluid helium temperature (4 cycles at 1.6 K). Each seal was mounted and demounted for 13 cycles. Thickness measurements at 90 deg intervals along the circumference showed a maximum seal compression of 0.038 mm. Leak-rate measurements at all temperatures showed no detectable leak above the helium background level, typically 0.1 x 10(-9) std-cc/sec, during testing.

  6. New stopping cell capabilities: RF carpet performance at high gas density and cryogenic operation

    NASA Astrophysics Data System (ADS)

    Ranjan, M.; Purushothaman, S.; Dickel, T.; Geissel, H.; Plass, W. R.; Schäfer, D.; Scheidenberger, C.; Van de Walle, J.; Weick, H.; Dendooven, P.

    2011-12-01

    We have developed a stopping cell to be used at the FRS and Super-FRS (Super-conducting FRagment Separator) at the GSI Helmholtz Centre for Heavy-Ion Research and the Facility for Antiproton and Ion Research (FAIR), both in Darmstadt, Germany. The cell has a stopping volume with a length of 1 m and a diameter of 25 cm. It is aimed at operation with high-density helium gas (up to 0.2 mg/cm3). Ours is the first realisation of a stopping cell in which the required purity of the helium stopping gas is ensured by operation at cryogenic temperatures. On the exit side, the ions are guided to the exit hole by an RF carpet with 4 electrodes per mm, operating at a frequency of 5.8 MHz. We present the first commissioning results of the cryogenic stopping cell. Using 219Rn ions emitted as alpha-decay recoils from a 223Ra source, a combined ion survival and extraction efficiency between 10 and 25% is measured for helium gas at a temperature of 85 K and with a density up to 0.07 mg/cm3 (equivalent to a pressure of 430 mbar at room temperature). This density is almost two times higher than demonstrated up to now for RF ion repelling structures in helium gas. Given the operational and design parameters of the system, it is projected that this technology is useful up to a helium gas density of at least 0.2 mg/cm3.

  7. Settled Cryogenic Propellant Transfer

    NASA Technical Reports Server (NTRS)

    Kutter, Bernard F.; Zegler, Frank; Sakla, Steve; Wall, John; Hopkins, Josh; Saks, Greg; Duffey, Jack; Chato, David J.

    2006-01-01

    Cryogenic propellant transfer can significantly benefit NASA s space exploration initiative. LMSSC parametric studies indicate that "Topping off" the Earth Departure Stage (EDS) in LEO with approx.20 mT of additional propellant using cryogenic propellant transfer increases the lunar delivered payload by 5 mT. Filling the EDS to capacity in LEO with 78 mT of propellants increases the delivered payload by 20 mT. Cryogenic propellant transfer is directly extensible to Mars exploration in that it provides propellant for the Mars Earth Departure stage and in-situ propellant utilization at Mars. To enable the significant performance increase provided by cryogenic propellant transfer, the reliability and robustness of the transfer process must be guaranteed. By utilizing low vehicle acceleration during the cryogenic transfer the operation is significantly simplified and enables the maximum use of existing, reliable, mature upper stage cryogenic-fluid-management (CFM) techniques. Due to settling, large-scale propellant transfer becomes an engineering effort, and not the technology development endeavor required with zero-gravity propellant transfer. The following key CFM technologies are all currently implemented by settling on both the Centaur and Delta IV upper stages: propellant acquisition, hardware chilldown, pressure control, and mass gauging. The key remaining technology, autonomous rendezvous and docking, is already in use by the Russians, and must be perfected for NASA whether the use of propellant transfer is utilized or not.

  8. High Frequency Performance of SiGeC HBTs with Selectively & Non-Selectively Grown Collector

    NASA Astrophysics Data System (ADS)

    Suvar, Erdal; Haralson, Erik; Radamson, Henry H.; Wang, Yong-Bin; Malm, B. Gunnar; Östling, Mikael

    2004-01-01

    Two high-frequency heterojunction bipolar transistor (HBT) architectures based on SiGeC have been fabricated and characterized. Different collector designs were applied either by using selective epitaxial growth doped with phosphorous or by nonselective epitaxial growth doped with arsenic. Both designs have a nonselectively deposited SiGeC base doped with boron and a poly-crystalline emitter doped with phosphorous. Both HBT designs exhibit similar electrical characteristics with a peak DC current gain of around 1600 and a BVCEO of 1.8V. The cut-off frequency (fT) and maximum frequency of oscillation (fmax) vary from 40 80GHz and 15 30GHz, respectively, depending on lateral design relations. Good high frequency performance for a device with a selectively grown collector is demonstrated for the first time.

  9. Cryogenic System for Interferometric Measurement of Dimensional Changes at 40 K: Design and Performance

    NASA Technical Reports Server (NTRS)

    Blake, Peter; Miller, Franklin; Zukowski, Tim; Canavan, Edgar R.; Crane, Allen; Madison, Tim; Miller, David

    2007-01-01

    This report describes the facility, experimental methods, characterizations, and uncertainty analysis of the Cryo Distortion Measurement Facility (CDMF) at the Goddard Space Flight Center (GSFC). This facility is designed to measure thermal distortions of structural elements as the temperature is lowered from 320K to below 40 K over multiple cycles, and is capable of unattended running and data logging. The first measurement is to be the change in length and any bending of composite tubes with Invar end-fittings. The CDMF includes a chamber that is efficiently cooled with two cryo-coolers (one single-stage and one two-stage) rather than with liquid cryogens. Five optical ports incorporate sapphire radiation shields - transparent to the interferometer - on each of two shrouds and a fused silica vacuum-port window. The change in length of composite tubes is monitored continuously with displacement-measuring interferometers; and the rotations, bending, and twisting are measured intermittently with theodolites and a surface-figure interferometer. Nickel-coated invar mirrors and attachment mechanisms were developed and qualified by test in the CDMF. The uncertainty in measurement of length change of 0.4 m tubes is currently estimated at 0.9 micrometers.

  10. An experimental study on fatigue performance of cryogenic metallic materials for IMO type B tank

    NASA Astrophysics Data System (ADS)

    Lee, Jin-Sung; You, Won-Hyo; Yoo, Chang-Hyuk; Kim, Kyung-Su; Kim, Yooil

    2013-12-01

    Three materials SUS304, 9% Ni steel and Al 5083-O alloy, which are considered possible candidate for International Maritime Organization (IMO) type B Cargo Containment System, were studied. Monotonic tensile, fatigue, fatigue crack growth rate and Crack Tip Opening Displacement tests were carried out at room, intermediate low (-100 °C) and cryogenic (-163 °C) temperatures. The initial yield and tensile strengths of all materials tended to increase with decreasing temperature, whereas the change in elastic modulus was not as remarkable. The largest and smallest improvement ratio of the initial yield strengths due to a temperature reduction were observed in the SUS304 and Al 5083- O alloy, respectively. The fatigue strengths of the three materials increased with decreasing temperature. The largest increase in fatigue strength was observed in the Al 5083-O alloy, whereas the 9% Ni steel sample showed the smallest increase. In the fatigue crack growth rate test, SUS304 and Al 5083-O alloy showed a decrease in the crack propagation rate, due to decrease in temperature, but no visible improvement in da/dN was observed in the case of 9% Ni steel. In the Crack Tip Opening Displacement (CTOD) test, CTOD values were converted to critical crack length for the comparison with different thickness specimens. The critical crack length tended to decrease in the case of SUS304 and increase for the Al 5083-O alloy with decreasing temperature. In case of 9% Ni steel, change of critical crack length was not observed due to temperature decrease. In addition, the changing material properties according to the temperature of the LNG tank were analyzed according to the international code for the construction and equipment of ships carrying liquefied gases in bulk (IGC code) and the rules of classifications.

  11. Cryogenic Systems

    NASA Astrophysics Data System (ADS)

    Hosoyama, Kenji

    2002-02-01

    In this lecture we discuss the principle of method of cooling to a very low temperature, i.e. cryogenic. The "gas molecular model" will be introduced to explain the mechanism cooling by the expansion engine and the Joule-Thomson expansion valve. These two expansion processes are normally used in helium refrigeration systems to cool the process gas to cryogenic temperature. The reverse Carnot cycle will be discussed in detail as an ideal refrigeration cycle. First the fundamental process of liquefaction and refrigeration cycles will be discussed, and then the practical helium refrigeration system. The process flow of the system and the key components; -compressor, expander, and heat exchanger- will be discussed. As an example of an actual refrigeration system, we will use the cryogenic system for the KEKB superconducting RF cavity. We will also discuss the liquid helium distribution system, which is very important, especially for the cryogenic systems used in accelerator applications. 1 Principles of Cooling and Fundamental Cooling Cycle 2 Expansion engine, Joule-Thomson expansion, kinetic molecular theory, and enthalpy 3 Liquefaction Systems 4 Refrigeration Systems 5 Practical helium liquefier/refrigeration system 6 Cryogenic System for TRISTAN Superconducting RF Cavity

  12. First performance of the GeMS + GMOS system - 1. Imaging

    NASA Astrophysics Data System (ADS)

    Hibon, Pascale; Garrel, Vincent; Neichel, Benoit; Prout, Benjamin; Rigaut, Francois; Koning, Alice; Carrasco, Eleazar R.; Gimeno, German; Pessev, Peter

    2016-09-01

    During the commissioning of the Gemini MCAO System (GeMS), we had the opportunity to obtain data with the Gemini Multi-Object Spectrograph (GMOS), the most utilized instrument at Gemini South Observatory, in 2012 March and May. Several globular clusters were observed in imaging mode that allowed us to study the performance of this new and untested combination. GMOS is a visible instrument, hence pushing MCAO towards the visible. We report here on the results with the GMOS instruments, derive photometric performance in term of full width at half-maximum (FWHM) and throughput. In most of the cases, we obtained an improvement factor of at least 2 against the natural seeing. This result also depends on the natural guide star constellation selected for the observations and we then study the impact of the guide star selection on the FWHM performance. We also derive a first astrometric analysis showing that the GeMS+GMOS system provide an absolute astrometric precision better than 8 mas and a relative astrometric precision lower than 50 mas.

  13. Evaluation of an 18-couple module composed of improved performance SiGe unicouples

    SciTech Connect

    Kelly, C.E.; Klee, P.M.; Nakahara, J.F.; Hartman, R.F.

    1995-12-31

    Radioisotope Thermoelectric Generators (RTGs) have played a major role in providing spacecraft electrical power for interplanetary exploration. Silicon Germanium alloys are the thermoelectric material employed in RTGs. Over the past several years a number of investigations have reported improvements in the figure of merit of these alloys. These improvements are attractive to mission planners because they result in enhanced RTG specific power (watts/lb) and improved efficiency which leads to lower fuel costs. This paper describes the fabrication and testing of an 18-couple module device utilizing unicouples with improved SiGe alloys. The unicouples were fabricated using materials with over a 10% improvement in the 573 to 1,273 K integrated average figure-of-merit over Cassini materials. The p-type material was fabricated by the standard vacuum casting and hot pressing method while the n-type material containing GaP was fabricated by a new method of mechanical alloying and hot isostatic pressing. The unicouples were fabricated in a similar fashion to standard unicouples except that the thermoelectric materials were bonded to the SiMo hot shoe in two thermal cycles due to the disparity of the melting points. A sufficient quantity of unicouples was fabricated to assemble an 18-couple module to evaluate the thermoelectric performance of the improved SiGe materials. The module was brought up to operating temperature following the same heatup rate as previous modules. The module was stabilized at a hot shoe temperature of 1,308 K. Initial performance was compared to the established SiGe database and found to show no improvement thermally or electrically.

  14. Cryogenic generator cooling

    NASA Astrophysics Data System (ADS)

    Eckels, P. W.; Fagan, T. J.; Parker, J. H., Jr.; Long, L. J.; Shestak, E. J.; Calfo, R. M.; Hannon, W. F.; Brown, D. B.; Barkell, J. W.; Patterson, A.

    The concept for a hydrogen cooled aluminum cryogenic generator was presented by Schlicher and Oberly in 1985. Following their lead, this paper describes the thermal design of a high voltage dc, multimegawatt generator of high power density. The rotor and stator are cooled by saturated liquid and supercritical hydrogen, respectively. The brushless exciter on the same shaft is also cooled by liquid hydrogen. Component development testing is well under way and some of the test results concerning the thermohydraulic performance of the conductors are reported. The aluminum cryogenic generator's characteristics are attractive for hydrogen economy applications.

  15. GeMS/GSAOI Photometric and Astrometric Performance in Dense Stellar Fields

    NASA Astrophysics Data System (ADS)

    Dalessandro, E.; Saracino, S.; Origlia, L.; Marchetti, E.; Ferraro, F. R.; Lanzoni, B.; Geisler, D.; Cohen, R. E.; Mauro, F.; Villanova, S.

    2016-12-01

    Ground-based imagers at 8 m class telescopes assisted by multi-conjugate adaptive optics are primary facilities with which to obtain accurate photometry and proper motions in dense stellar fields. We observed the central region of the globular clusters Liller 1 and NGC 6624 with the Gemini Multi-conjugate Adaptive Optics System (GeMS) feeding the Gemini South Adaptive Optics Imager (GSAOI) currently available at the Gemini South telescope, under different observing conditions. We characterized the stellar point-spread function (PSF) in terms of FWHM, Strehl ratio (SR), and encircled energy (EE), over the field of view (FOV). We found that, for sub-arcsecond seeing at the observed airmass, we can obtain the diffraction-limited PSF (FWHM ≈ 80 mas), SR ∼ 40%, and EE ≥ 50% with a dispersion around 10% over the FOV of 85″ × 85″, in the K s band. In the J band the best images provide FWHMs between 60 and 80 mas, SR \\gt 10 % , and {EE}\\gt 40 % . For seeing at the observed airmass exceeding 1″, the performance worsens but it is still possible to perform PSF fitting photometry with 25% EE in J and 40% in K s . We also computed the geometric distortions of GeMS/GSAOI and we obtained corrected images with an astrometric accuracy of ∼1 mas in a stellar field with high crowding.

  16. Performance of the active sidewall boundary-layer removal system for the Langley 0.3-meter Transonic Cryogenic Tunnel

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.; Kilgore, W. Allen; Murthy, A. V.

    1989-01-01

    A performance evaluation of an active sidewall boundary-layer removal system for the Langley 0.3-m Transonic Cryogenic Tunnel (TCT) was evaluated in 1988. This system uses a compressor and two throttling digital valves to control the boundary-layer mass flow removal from the tunnel. The compressor operates near the maximum pressure ratio for all conditions. The system uses a surge prevention and flow recirculation scheme. A microprocessor based controller is used to provide the necessary mass flow and compressor pressure ratio control. Initial tests on the system indicated problems in realizing smooth mass flow control while running the compressor at high speed and high pressure ratios. An alternate method has been conceived to realize boundary-layer mass flow control which avoids the recirculation of the compressor mass flow and operation near the compressor surge point. This scheme is based on varying the speed of the compressor for a sufficient pressure ratio to provide needed mass flow removal. The system has a mass flow removal capability of about 10 percent of test section flow at M = 0.3 and 4 percent at M = 0.8. The system performance has been evaluated in the form of the compressor map, and compressor tunnel interface characteristics covering most of the 0.3-m TCT operational envelope.

  17. CMOS reliability issues for emerging cryogenic Lunar electronics applications

    NASA Astrophysics Data System (ADS)

    Chen, Tianbing; Zhu, Chendong; Najafizadeh, Laleh; Jun, Bongim; Ahmed, Adnan; Diestelhorst, Ryan; Espinel, Gustavo; Cressler, John D.

    2006-06-01

    We investigate the reliability issues associated with the application of CMOS devices contained within an advanced SiGe HBT BiCMOS technology to emerging cryogenic space electronics (e.g., down to 43 K, for Lunar missions). Reduced temperature operation improves CMOS device performance (e.g., transconductance, carrier mobility, subthreshold swing, and output current drive), as expected. However, operation at cryogenic temperatures also causes serious device reliability concerns, since it aggravates hot-carrier effects, effectively decreasing the inferred device lifetime significantly, especially at short gate lengths. In the paper, hot-carrier effects are demonstrated to be a stronger function of the device gate length than the temperature, suggesting that significant trade-offs between the gate length and the operational temperature must be made in order to ensure safe and reliable operation over typical projected mission lifetimes in these hostile environments.

  18. Cryogenic shutter

    NASA Technical Reports Server (NTRS)

    Barney, Richard D. (Inventor); Magner, Thomas J. (Inventor)

    1991-01-01

    A magnetically operated shutter mechanism is provided that will function in cryogenic or cryogenic zero gravity environments to selectively block radiation such as light from passing through a window to a target object such as a mirror or detector located inside a cryogenic container such as a dewar. The mechanism includes a shutter paddle blade that is moved by an electromagnetically actuated torquing device between an open position where the target object is exposed to ambient radiation or light and a closed position where the shutter paddle blade shields the ambient radiation or light from the target object. The purpose of the shuttering device is to prevent the mirror or other target object from being directly exposed to radiation passing through the window located on the side wall of the dewar, thereby decreasing or eliminating any temperature gradient that would occur within the target object due to exposure to the radiation. A special nylon bearing system is utilized to prevent the device from binding during operation and the paddle blade is also termally connected to a reservoir containing the cryogen to further reduce the internal temperature.

  19. Cryogenic shutter

    NASA Technical Reports Server (NTRS)

    Barney, Richard D. (Inventor); Magner, Thomas J. (Inventor)

    1992-01-01

    A magnetically operated shutter mechanism is provided that will function in cryogenic or cryogenic zero gravity environments to selectively block radiation such as light from passing through a window to a target object such as a mirror or detector located inside a cryogenic container such as a dewar. The mechanism includes a shutter paddle blade that is moved by an electromagnetically actuated torquing device between an open position where the target object is exposed to ambient radiation or light and a closed position where the shutter paddle blade shields the ambient radiation or light from the target object. The purpose of the shuttering device is to prevent the mirror or other target object from being directly exposed to radiation passing through the window located on the side wall of the dewar, thereby decreasing or eliminating any temperature gradient that would occur within the target object due to exposure to the radiation. A special nylon bearing system is utilized to prevent the device from binding during operation and the paddle blade is also thermally connected to a reservoir containing cryogen to further reduce the internal temperature.

  20. Experimental measurements and theoretical model of the cryogenic performance of bialkali photocathode and characterization with Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Xie, Huamu; Ben-Zvi, Ilan; Rao, Triveni; Xin, Tianmu; Wang, Erdong

    2016-10-01

    High-average-current, high-brightness electron sources have important applications, such as in high-repetition-rate free-electron lasers, or in the electron cooling of hadrons. Bialkali photocathodes are promising high-quantum-efficiency (QE) cathode materials, while superconducting rf (SRF) electron guns offer continuous-mode operation at high acceleration, as is needed for high-brightness electron sources. Thus, we must have a comprehensive understanding of the performance of bialkali photocathode at cryogenic temperatures when they are to be used in SRF guns. To remove the heat produced by the radio-frequency field in these guns, the cathode should be cooled to cryogenic temperatures. We recorded an 80% reduction of the QE upon cooling the K2CsSb cathode from room temperature down to the temperature of liquid nitrogen in Brookhaven National Laboratory (BNL)'s 704 MHz SRF gun. We conducted several experiments to identify the underlying mechanism in this reduction. The change in the spectral response of the bialkali photocathode, when cooled from room temperature (300 K) to 166 K, suggests that a change in the ionization energy (defined as the energy gap from the top of the valence band to vacuum level) is the main reason for this reduction. We developed an analytical model of the process, based on Spicer's three-step model. The change in ionization energy, with falling temperature, gives a simplified description of the QE's temperature dependence. We also developed a 2D Monte Carlo code to simulate photoemission that accounts for the wavelength-dependent photon absorption in the first step, the scattering and diffusion in the second step, and the momentum conservation in the emission step. From this simulation, we established a correlation between ionization energy and reduction in the QE. The simulation yielded results comparable to those from the analytical model. The simulation offers us additional capabilities such as calculation of the intrinsic emittance

  1. Design and performance of a cryogenic scanning tunneling microscope in high magnetic field for 2D layered materials study

    NASA Astrophysics Data System (ADS)

    Chuang, Tien-Ming; Chung, Pei-Fang; Guan, Syu-You; Yu, Shan-An; Liu, Che-An; Hsu, Chia-Sheng; Su, Chih-Chuan; Sankar, Raman; Chou, Fang-Cheng

    2015-03-01

    We will describe the design and performance of a cryogenic scanning tunneling microscope (STM) system in a high magnetic field. A Pan-type STM is mounted on a homemade low vibration 4He pot refrigerator, which can be operated in continuous flow mode at T ~ 1.6K and in a magnetic field of up to 9 Tesla. A cleavage device at T =4.2K stage is used to cleave the 2D layered materials before inserting into STM as well as functioning as the radiation shield. The liquid helium boil rate of 4.6 liters per day is achieved due to our careful design, which allows the measurement at base temperature up to 10 days. We will demonstrate its capability of measuring atomically registered energy resolved spectroscopic maps in both real space and momentum space by our recent results on Rashba BiTeI. This work is supported by Ministry of Science and Technology, Taiwan and Kenda Foundation, Taiwan.

  2. Cryogenic storage tank thermal analysis

    NASA Technical Reports Server (NTRS)

    Wright, J. P.

    1976-01-01

    Parametric study discusses relationship between cryogenic boil-off and factors such as tank size, insulation thickness and performance, structural-support heat leaks and use of vapor-cooled shields. Data presented as series of nomographs and curves.

  3. Effect of deep cryogenic treatment on the microstructure and wear performance of Cr-Mn-Cu white cast iron grinding media

    NASA Astrophysics Data System (ADS)

    Vidyarthi, M. K.; Ghose, A. K.; Chakrabarty, I.

    2013-12-01

    The phase transformation and grinding wear behavior of Cr-Mn-Cu white cast irons subjected to destabilization treatment followed by air cooling or deep cryogenic treatment were studied as a part of the development program of substitute alloys for existing costly wear resistant alloys. The microstructural evolution during heat treatment and the consequent improvement in grinding wear performance were evaluated with optical and scanning electron microscopy, X-ray diffraction analysis, bulk hardness, impact toughness and corrosion rate measurements, laboratory ball mill grinding wear test etc. The deep cryogenic treatment has a significant effect in minimizing the retained austenite content and converts it to martensite embedded with fine M7C3 alloy carbides. The cumulative wear losses in cryotreated alloys are lesser than those with conventionally destabilized alloys followed by air cooling both in wet and dry grinding conditions. The cryotreated Cr-Mn-Cu irons exhibit comparable wear performance to high chromium irons.

  4. Thermal Performance of Biological Substance Systems in Vitro Under Static and Dynamic Conditions at the Cryogenic Test Laboratory, NASA Kennedy Space Center, USA

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, James E.; Steinrock, T. (Technical Monitor)

    2001-01-01

    A unique research program, including a comprehensive study of thermal performance at cryogenic vacuum insulation systems, was performed at the NASA Kennedy Space Center. The main goal was to develop a new soft vacuum system (from 1 torr to 10 torr) that provides an intermediate level of performance (k-value below 4.8 mW/m-K). Liquid nitrogen boil-off methods were used to test conventional materials, novel materials, and certain combinations. The test articles included combinations of aluminum foil, fiberglass paper, polyester fabric, silica aerogel composite blanket, fumed silica, silica aerogel powder, and syntactic foam. A new LCI system was developed at the Cryogenics Test Laboratory. This system performs exceptionally well at soft vacuum levels and nearly as good as an MLI at high vacuum levels. Apparent thermal conductivities for the LCI range from 2 mW/m-K at soft vacuum to 0.1 mW/m-K at high vacuum. Several cryostats were designed, constructed, and calibrated by the Cryogenics Test Laboratory at KSC NASA as part of this research program. The cryostat test apparatus is a liquid nitrogen boil-off calorimeter system for direct measurement of the apparent thermal conductivity at a fixed vacuum level between 5 x 10(exp -5) and 760 torr. The apparatus is also used for transient measurements of temperature profiles. The development of efficient, robust cryogenic insulation systems has been a targeted area of research for a number of years. Improved methods of characterization, testing, and evaluation of complex biological substance systems for cryosurgery and cryobiology are the focus of this paper.

  5. The in-vacuo torque performance of dry-lubricated ball bearings at cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Gould, S. G.; Roberts, E. W.

    1989-01-01

    The performance of dry-lubricated, angular contact ball bearings in vacuum at a temperature of 20 degrees K has been investigated, and is compared with the in-vacuo performance at room temperatures. Bearings were lubricated using dry-lubricant techniques which have been previously established for space applications involving operations at or near room temperature. Comparative tests were undertaken using three lubricants: molybdenum disulphide, lead, and PTFE. Results obtained using the three lubricants are presented.

  6. High performance LWIR microbolometer with Si/SiGe quantum well thermistor and wafer level packaging

    NASA Astrophysics Data System (ADS)

    Roer, Audun; Lapadatu, Adriana; Bring, Martin; Wolla, Erik; Hohler, Erling; Kittilsland, Gjermund

    2011-11-01

    An uncooled microbolometer with peak responsivity in the long wave infrared region of the electromagnetic radiation is developed at Sensonor Technologies. It is a 384 x 288 focal plane array with a pixel pitch of 25μm, based on monocrystalline Si/SiGe quantum wells as IR sensitive material. The high sensitivity (TCR) and low 1/f noise are the main performance characteristics of the product. The frame rate is maximum 60Hz and the output interface is digital (LVDS). The quantum well thermistor material is transferred to the read-out integrated circuit (ROIC) by direct wafer bonding. The ROIC wafer containing the released pixels is bonded in vacuum with a silicon cap wafer, providing hermetic encapsulation at low cost. The resulting wafer stack is mounted in a standard ceramic package. In this paper the architecture of the pixels and the ROIC, the wafer packaging and the electro-optical measurement results are presented.

  7. Performance of multiplexed Ge:Ga detector arrays in the far infrared

    NASA Technical Reports Server (NTRS)

    Farhoomand, Jam; Mccreight, Craig

    1990-01-01

    The performance of two multi-element, multiplexed Ge:Ga linear arrays under low-background conditions was investigated. The on-focal switching is accomplished by MOSFET switches, and the integrated charge is made available through MOSFET source followers. The tests were conducted at 106 microns, and the radiation on the detectors was confined to a spectral window 1.25 microns wide using a stack of cold filters. At 4.2 K, the highest responsivity was 584 A/W, the noise equivalent power was 1.0 x 10(exp -16) W/square root of Hz, and the read noise was 6100 electrons/sample. A detailed description of the test setup and procedure is presented.

  8. Flight electronics for vibration cancellation in cryogenic refrigerators: performance and environmental testing results

    NASA Astrophysics Data System (ADS)

    Burriesci, Lawrence G.; Cook, Eric I.; Hackett, John P.; Drummond, James R.; Mand, Gurpreet S.

    1996-10-01

    Space flight optical instruments and their support hardware must reliably operate in stressing environments for the duration of their mission. They must also survive the mechanical and thermal stresses of transportation, storage and launch. It is necessary to qualify the hardware design through environmental testing and to verify the hardware's ability to perform properly during and/or after some selected environmental tests on the ground. As a rule, flight electronics are subjected to thermal, mechanical and electromagnetic environmental testing. Thermal testing takes the form of temperature cycling over a temperature difference range (Delta) T of up to 100 degrees C for a minimum of six cycles, with additional performance verification testing at the hot and cold extremes. Mechanical testing takes the form of exposure to random vibration, sine sweep vibration, shock spectra and static loading on a centrifuge or by sine burst on a vibration table. A standard series of electromagnetic interference and electromagnetic compatibility testing is also performed.

  9. Performance of a Cryogenic 21 Meter-Path Copper Herriott Cell Vacuum Coupled to a Bruker 125HR System

    NASA Astrophysics Data System (ADS)

    Mantz, Arlan W.; Sung, Keeyoon; Crawford, Timothy J.; Yu, Shanshan; Brown, Linda R.; Smith, Mary Ann H.; Devi, V. Malathy; Benner, D. Chris

    2013-06-01

    Accurate modeling of planetary atmospheres requires a detailed knowledge of the temperature and pressure dependence of spectroscopic line parameters of atmospheric molecules. With this requirement in mind, a new Herriott cell having a 21 meter folded absorption path was designed and fabricated with Oxygen-Free High Conductivity (OFHC) copper body and gold coated OFHC copper mirrors to operate for the first time with a broad-band Fourier transform spectrometer. The cell, enclosed in an isolated vacuum box, is cooled by a CTI Cryogenics, Inc. model 1050 closed-cycle helium refrigerator which also cryopumps the vacuum box. The temperature of the cell is monitored by a silicon temperature sensor and regulated by a Lakeshore model 331 temperature controller. The new cell system was integrated to the JPL Bruker model 125HR interferometer with transfer optics which are fully evacuated to 12 mTorr (the pressure inside the interferometer). The optics were through-put matched for entrance apertures smaller than 2 mm. The system has successfully operated for several months at gas sample temperatures between 75 and 250 K with extremely good stability to obtain spectra of methane, carbon dioxide, and oxygen bands between 0.76 and 3 μm. We present the characterization and performance of the Herriott cell system and preliminary analyses of newly recorded spectra. Research described in this paper was performed at Connecticut College, the Jet Propulsion Laboratory, California Institute of Technology, NASA Langley Research Center, and The College of William and Mary under contracts and cooperative agreements with the National Aeronautics and Space Administration.

  10. Cryogenic Fluid Transfer for Exploration

    NASA Technical Reports Server (NTRS)

    Chato, David J.

    2008-01-01

    This paper discusses current plans and issues for exploration that involve the use of cryogenic transfer. The benefits of cryogenic transfer to exploration missions are examined. The current state of the art of transfer technology is reviewed. Mission concepts of operation for exploration are presented, and used to qualitatively discuss the performance benefits of transfer. The paper looks at the challenges faced to implement a cryogenic transfer system and suggest approaches to address them with advanced development research. Transfer rates required for exploration are shown to have already been achieved in ground test. Cost-effective approaches to the required on-orbit demonstration are suggested.

  11. Cryogenic Fluid Transfer for Exploration

    NASA Technical Reports Server (NTRS)

    Chato, David J.

    2007-01-01

    This paper discusses current plans and issues for exploration that involve the use of cryogenic transfer. The benefits of cryogenic transfer to exploration missions are examined. The current state of the art of transfer technology is reviewed. Mission concepts of operation for exploration are presented, and used to qualitatively discuss the performance benefits of transfer. The paper looks at the challenges faced to implement a cryogenic transfer system and suggest approaches to address them with advanced development research. Transfer rates required for exploration are shown to have already been achieved in ground test. Cost effective approaches to the required on-orbit demonstration are suggested.

  12. CRYOGENIC MAGNETS

    DOEpatents

    Post, R.F.; Taylor, C.E.

    1963-05-21

    A cryogenic magnet coil is described for generating magnetic fields of the order of 100,000 gauss with a minimum expenditure of energy lost in resistive heating of the coil inductors and energy lost irreversibly in running the coil refrigeration plant. The cryogenic coil comprises a coil conductor for generating a magnetic field upon energization with electrical current, and refrigeration means disposed in heat conductive relation to the coil conductor for cooling to a low temperature. A substantial reduction in the power requirements for generating these magnetic fields is attained by scaling the field generating coil to large size and particular dimensions for a particular conductor, and operating the coil at a particular optimum temperature commensurate with minimum overall power requirements. (AEC)

  13. Investigations on Absorber Materials at Cryogenic Temperatures

    SciTech Connect

    Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

    2009-05-01

    In the framework of the 12 GeV upgrade project for the Continuous Electron Beam Accelerator Facility (CEBAF) improvements are being made to refurbish cryomodules housing Thomas Jefferson National Accelerator Facility's (JLab) original 5-cell cavities. Recently we have started to look into a possible simplification of the existing Higher Order Mode (HOM) absorber design combined with the aim to find alternative material candidates. The absorbers are implemented in two HOM-waveguides immersed in the helium bath and operate at 2 K temperature. We have built a cryogenic setup to perform measurements on sample load materials to investigate their lossy characteristics and variations from room temperature down to 2 K. Initial results are presented in this paper.

  14. Epitaxial Technologies for SiGeSn High Performance Optoelectronic Devices

    DTIC Science & Technology

    2015-04-29

    SiSn, GeSn, and SiGeSn on Si substrate has been demonstrated. Both SnCl4 and SnD4 are used as Sn precursors for GeSn and SiGeSn growth. So far 276...2014) 40 10 10 40 0 15 0 Number of round (Oct.~Dec. 2014) 5* 34 0 2 34 12 22 Number of round (Jan.~ Mar . 2015) 4** 0 0 43 5 0 0 Total Number...to Si substrate peak, while incorporating of Sn shifts the peak away from the Si substrate peak, which agrees well with theoretical study. Figure

  15. Use of simple x-ray measurement in the performance analysis of cryogenic RF accelerator cavities

    SciTech Connect

    D. Dotson; M. Drury; R. May; C. Reece

    1996-10-01

    X-ray emission by radiofrequency (RF) resonant cavities has long been known to accelerator health physicists as a potentially serious source of radiation exposure. The authors points out the danger of klystrons and microwave cavities by stating that the radiation source term is erratic and may be unpredictable depending on microscopic surface conditions which change with time. He also states the x-ray output is a rapidly increasing function of RF input power. At Jefferson Lab, the RF cavities used to accelerate the electron beam employ superconducting technology. X-rays are emitted at high cavity gradients, and measurements of cavity x-rays are valuable for health physics purposes and provide a useful diagnostic tool for assessing cavity performance. The quality factor (Q) for superconducting RF resonant cavities used at Jefferson Lab, is typically 5 x 10{sup 9} for the nominal design gradient of 5 MVm{sup {minus}1}. This large value for Q follows from the small resistive loss in superconducting technology. The operating frequency is 1,497 MHz. In the absence of beam, the input power for a cavity is typically 750 W and the corresponding dissipated power is 2.6 W. At 5 MWm{sup {minus}1}, the input power is 3 kW fully beam loaded. At higher gradients, performance degradation tends to occur due to the onset of electron field emission from defects in the cavity.

  16. Unlocking the Origin of Superior Performance of a Si-Ge Core-Shell Nanowire Quantum Dot Field Effect Transistor.

    PubMed

    Dhungana, Kamal B; Jaishi, Meghnath; Pati, Ranjit

    2016-07-13

    The sustained advancement in semiconducting core-shell nanowire technology has unlocked a tantalizing route for making next generation field effect transistor (FET). Understanding how to control carrier mobility of these nanowire channels by applying a gate field is the key to developing a high performance FET. Herein, we have identified the switching mechanism responsible for the superior performance of a Si-Ge core-shell nanowire quantum dot FET over its homogeneous Si counterpart. A quantum transport approach is used to investigate the gate-field modulated switching behavior in electronic current for ultranarrow Si and Si-Ge core-shell nanowire quantum dot FETs. Our calculations reveal that for the ON state, the gate-field induced transverse localization of the wave function restricts the carrier transport to the outer (shell) layer with the pz orbitals providing the pathway for tunneling of electrons in the channels. The higher ON state current in the Si-Ge core-shell nanowire FET is attributed to the pz orbitals that are distributed over the entire channel; in the case of Si nanowire, the participating pz orbital is restricted to a few Si atoms in the channel resulting in a smaller tunneling current. Within the gate bias range considered here, the transconductance is found to be substantially higher in the case of a Si-Ge core-shell nanowire FET than in a Si nanowire FET, which suggests a much higher mobility in the Si-Ge nanowire device.

  17. A Piezoelectric Cryogenic Heat Switch

    NASA Technical Reports Server (NTRS)

    Jahromi, Amir E.; Sullivan, Dan F.

    2014-01-01

    We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios greater than 100 were achieved when the positioner applied its maximum force of 8 N. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an optimized PZHS.

  18. Performance of high-altitude, long-endurance, turboprop airplanes using conventional or cryogenic fuels

    NASA Technical Reports Server (NTRS)

    Liu, G. C.; Morris, C. E. K., Jr.; Koenig, R. W.

    1983-01-01

    An analytical study has been conducted to evaluate the potential endurance of remotely piloted, low speed, high altitude, long endurance airplanes designed with 1990 technology. The baseline configuration was a propeller driven, sailplane like airplane powered by turbine engines that used JP-7, liquid methane, or liquid hydrogen as fuel. Endurance was measured as the time spent between 60,000 feet and an engine limited maximum altitude of 70,000 feet. Performance was calculated for a baseline vehicle and for configurations derived by varying aerodynamic, structural or propulsion parameters. Endurance is maximized by reducing wing loading and engine size. The level of maximum endurance for a given wing loading is virtually the same for all three fuels. Constraints due to winds aloft and propulsion system scaling produce maximum endurance values of 71 hours for JP-7 fuel, 70 hours for liquid methane, and 65 hours for liquid hydrogen. Endurance is shown to be strongly effected by structural weight fraction, specific fuel consumption, and fuel load. Listings of the computer program used in this study and sample cases are included in the report.

  19. Performance of a hypersonic hot fuselage structure with a carbon dioxide frost projected, nonintegral cryogenic tank

    NASA Technical Reports Server (NTRS)

    Sharpe, E. L.; Jackson, L. R.

    1975-01-01

    A model which consisted of a hot structure and a nonintegral tank protected by a carbon dioxide frost thermal protection system was tested under the following conditions: (1) room temperature loading and (2) heating and loading corresponding to the Mach 8 flight of an air-breathing launch vehicle. In the simulated flight tests, liquid nitrogen inside the tank was withdrawn at the rate fuel would be consumed. Prior to each simulated flight test, carbon dioxide was cryodeposited in the insulation surrounding the tank; during the tests, subliming CO2 frost absorbed heat and provided a purge gas for the space between the tank and the structure. A method of flame spraying the joints between panels with a nickel-aluminum material was developed to prevent excessive leakage of the purge gas through the outer structure. The tests indicated that the hot structure (with a joint repaired by riveting), the nonintegral tank and suspension system, and the carbon dioxide frost thermal protection system provide a workable concept with predictable performance.

  20. Cryogenic performances of T700 and T800 carbon fibre- epoxy laminates

    NASA Astrophysics Data System (ADS)

    Wei, Wang; Rongjin, Huang; Chuanjun, Huang; Zhao, Yuqiang; Li, Shaopeng; Laifeng, Li

    2015-12-01

    The temperature dependence of thermal expansion, thermal conductivity and mechanical properties of T700 carbon fibre (T700 CFs) /epoxy composite and T800 CF/epoxy composite were investigated. The mechanical and thermal properties of the unidirectional composite material laminates (0°/90°) at low temperature were studied. The results show that comparing the composite material T700 CFs with T800 CFs, the thermal expansion and thermal conductivity performances of T800 CFs (0°/90°) are all smaller than those of T700 CFs. Typically, the coefficient of thermal expansion (CTE) of T800 CFs in 0° is very low in the temperature range of 120-300K, which reaches as low as -0.4×10-6 K-1. The value of thermal conductivity of this material at 0° is about 3.2 W.(m.K)-1 at room temperature. Tensile and compression tests indicate that the tensile strength of T800 CFs in 0° direction at 77K reaches 2310 MPa, while the compressive strength is about 852 MPa. This composite material may possibly be exploited to design the critical components for practical applications such as hydrogen storage tanks.

  1. Cryogenic performance of a conduction-cooling splittable quadrupole magnet for ILC cryomodules

    SciTech Connect

    Kimura, N.; Yamamoto, A.; Andreev, N.; Kashikhin, V. S.; Tartaglia, M. A.; Kerby, J.; Takahashi, M.; Tosaka, T.

    2014-01-29

    A conduction-cooled splittable superconducting quadrupole magnet was designed and fabricated at Fermilab for use in cryomodules of the International Linear Collider (ILC) type, in which the magnet was to be assembled around the beam tube to avoid contaminating the ultraclean superconducting radio frequency cavity volume. This quadrupole was first tested in a liquid helium bath environment at Fermilab, where its quench and magnetic properties were characterized. Because the device is to be cooled by conduction when installed in cryomodules, a separate test with a conduction-cooled configuration was planned at KEK and Fermilab. The magnet was converted to a conduction-cooled configuration by adding conduction-cooling passages made of high-purity aluminum. Efforts to convert and refabricate the magnet into a cryostat equipped with a double-stage pulse-tube-type cryocooler began in 2011, and a thermal performance test, including a magnet excitation test of up to 30 A, was conducted at KEK. In this test, the magnet with the conduction-cooled configuration was successfully cooled to 4 K within 190 h, with an acceptable heat load of less than 1 W at 4 K. It was also confirmed that the conduction-cooled splittable superconducting quadrupole magnet was practical for use in ILC-type cryomodules.

  2. Cryogenic optical systems and instruments IV; Proceedings of the Meeting, San Diego, CA, July 10-12, 1990

    NASA Technical Reports Server (NTRS)

    Melugin, Ramsey K. (Editor); Pruitt, Gerald R. (Editor)

    1990-01-01

    Consideration is given to cryogenic system design and optical technology; cryogenic instruments, sensors, and detectors; space cryogenic dewars and coolers; and cryogenic mechanisms, testing, and structures. Particular attention is given to mission optimization of the Space Infrared Telescope Facility (SIRTF), alternative aperture stop position designs for SIRTF, scaling laws for lightweight optics, evaluation of a far-infrared Ge:Ga multiplexed detector array, cryogenic limb array etalon spectrometer calibration, reliability growth of coolers for advanced optical systems and instruments, flight-qualified solid argon cooler for the BBXRT instrument, precision mechanisms for optical alignments at cryogenic temperatures, versatile cryogenic rotary-positioning systems, and optical alignments of the Cosmic Background Explorer observatory.

  3. Thermal endurance and microstructural evolution of PtGe for high-performance nano-scale Ge-on-Si MOSFETS.

    PubMed

    Kang, Min-Ho; Shin, Hong-Sik; Oh, Se-Kyung; Yoo, Jung-Ho; Lee, Ga-Won; Oh, Jung-Woo; Majhi, Prashant; Jammy, Raj; Lee, Hi-Deok

    2011-07-01

    The thermal endurance and microstructural evolution of Ni-germanide (NiGe) and Pt-germanide (PtGe) on a Ge-on-Si substrate were compared in this paper. In case of the Ni/TiN structure, the sheet resistance exhibited a stable RTP window of 350 to 600 degrees C, while that of the Pt/TiN structure showed more stable characteristics up to 700 degrees C. Furthermore, after post-germanidation annealing, NiGe exhibited the formation of islands due to the severe agglomeration as well as a prominent grain boundary grooving, which accounts for the sharp increase of the sheet resistance from 550 degrees C, whereas PtGe showed a smooth and continuous surface morphological stability without signs of agglomeration even up to 600 degrees C. Although about two times higher resistivity (31.5 micro ohms-cm) and greater Ge consumption (3.27 nm) were shown, PtGe showed more stable sheet resistance, better surface and interface morphological stability and a wider thermal processing window above 100 degrees C than NiGe. Therefore, PtGe is more suitable for the germanided shallow source/drain for nano-scale Ge MOSFETs than NiGe.

  4. ILC cryogenic systems reference design

    SciTech Connect

    Peterson, T.J.; Geynisman, M.; Klebaner, A.; Theilacker, J.; Parma, V.; Tavian, L.; /CERN

    2008-01-01

    A Global Design Effort (GDE) began in 2005 to study a TeV scale electron-positron linear accelerator based on superconducting radio-frequency (RF) technology, called the International Linear Collider (ILC). In early 2007, the design effort culminated in a reference design for the ILC, closely based on the earlier TESLA design. The ILC will consist of two 250 GeV linacs, which provide positron-electron collisions for high energy physics research. The particle beams will be accelerated to their final energy in superconducting niobium RF cavities operating at 2 kelvin. At a length of about 12 km each, the main linacs will be the largest cryogenic systems in the ILC. Positron and electron sources, damping rings, and beam delivery systems will also have a large number and variety of other superconducting RF cavities and magnets, which require cooling at liquid helium temperatures. Ten large cryogenic plants with 2 kelvin refrigeration are envisioned to cool the main linacs and the electron and positron sources. Three smaller cryogenic plants will cool the damping rings and beam delivery system components predominately at 4.5 K. This paper describes the cryogenic systems concepts for the ILC.

  5. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  6. Catalyst engineering for lithium ion batteries: the catalytic role of Ge in enhancing the electrochemical performance of SnO2(GeO2)0.13/G anodes.

    PubMed

    Zhu, Yun Guang; Wang, Ye; Han, Zhao Jun; Shi, Yumeng; Wong, Jen It; Huang, Zhi Xiang; Ostrikov, Kostya Ken; Yang, Hui Ying

    2014-12-21

    The catalytic role of germanium (Ge) was investigated to improve the electrochemical performance of tin dioxide grown on graphene (SnO(2)/G) nanocomposites as an anode material of lithium ion batteries (LIBs). Germanium dioxide (GeO(20) and SnO(2) nanoparticles (<10 nm) were uniformly anchored on the graphene sheets via a simple single-step hydrothermal method. The synthesized SnO(2)(GeO(2))0.13/G nanocomposites can deliver a capacity of 1200 mA h g(-1) at a current density of 100 mA g(-1), which is much higher than the traditional theoretical specific capacity of such nanocomposites (∼ 702 mA h g(-1)). More importantly, the SnO(2)(GeO(2))0.13/G nanocomposites exhibited an improved rate, large current capability (885 mA h g(-1) at a discharge current of 2000 mA g(-1)) and excellent long cycling stability (almost 100% retention after 600 cycles). The enhanced electrochemical performance was attributed to the catalytic effect of Ge, which enabled the reversible reaction of metals (Sn and Ge) to metals oxide (SnO(2) and GeO(2)) during the charge/discharge processes. Our demonstrated approach towards nanocomposite catalyst engineering opens new avenues for next-generation high-performance rechargeable Li-ion batteries anode materials.

  7. Effect of casing treatment on performance of a multistage compressor. [J85-GE-13 engine tests

    NASA Technical Reports Server (NTRS)

    Wenzel, L. M.; Moss, J. E., Jr.; Mehalic, C. M.

    1975-01-01

    AJ85-GE-13 engine was equipped with a compressor case which allowed changes to the case wall over the rotor tips of six of its stages. The engine was tested with four inlet configurations: undistorted and with 180 deg circumferential, hub radial, and tip radial distortions. Baseline data defining compressor performance and stall regions were taken for these inlet configurations with solid (untreated) compressor case inserts. Circumferentially grooved inserts were installed in the first three and last three stages, and the compressor was mapped under similar conditions. The compressor was mapped a third time with untreated inserts in the first three stages and inserts having slots conforming to blade angles in the last three stages. In most cases, the stall pressure ratio was the same as or lower than the baseline. Pumping capacity with the slotted inserts was reduced. Overall compressor efficiency with the grooved rings installed did not appreciably differ from the baseline, but it was 1 to 2 percentage points lower than the baseline with the slotted rings in place. Average stage characteristics for the undistorted inlet case showed little or no sensitivity to casing treatment.

  8. Finite-element simulation of the performance of a superconducting meander structure shielding for a cryogenic current comparator

    NASA Astrophysics Data System (ADS)

    De Gersem, H.; Marsic, N.; Müller, W. F. O.; Kurian, F.; Sieber, T.; Schwickert, M.

    2016-12-01

    The ferrite core and measuring coil of a cryogenic current comparator have to be shielded against external magnetic fields by a compact, efficient meander structure made of superconducting niobium. A design with minimized material and production costs is only feasible when a highly accurate magnetic field simulator is available. 3D field models become prohibitively large. The cylindrical symmetry of the devices motivates to develop a quasi-3D field solver, exploiting the symmetry while still capable of representing 3D field distributions.

  9. Advances of cryogenics in aeronautics and astronautics

    NASA Astrophysics Data System (ADS)

    You, Lixin

    1992-02-01

    The application principles of cryogenic techniques in aerospace are discussed in detail. Recent advances are addressed, including those made in China. These include: (1) characteristics and applications of rockets propelled by cryogenic liquid hydrogen (LOH)/LOX fuels and those propelled by a new generation of cryogenic liquid propellants; (2) characteristics and status of LOH/LOX-fueled and LNG-fueled aircraft; (3) principles and working envelopes of cryogenic wind tunnels performing aerodynamic experiments at full-scale Re; (4) the main application fields of cryogenics in space technology and their requirements regarding refrigeration temperature and load; (5) the application of cryogenics to fields such as cooling reentry flight vehicles, space simulation facilities, environmental control systems for flight vehicles, and life support systems.

  10. Advances in cryogenic engineering. Volume 29

    SciTech Connect

    Fast, R.W.

    1984-01-01

    Applications of superconductivity are discussed, taking into account the thermal performance of the MFTF magnets, the design and testing of a large bore superconducting magnet test facility, the development of a 12-tesla multifilamentary Nb3Sn magnet, a superconducting magnet for solid NMR studies, advanced applications of superconductors, transition and recovery of a cryogenically stable superconductor, and finite-difference modeling of the cryostability of helium II cooled conductor packs. Other topics explored are related to resource availability, heat exchangers, heat transfer to He I, liquid nitrogen, heat transfer in He II, refrigeration for superconducting and cryopump systems, refrigeration of cryogenic systems, refrigeration and liquefaction, dilution and magnetic refrigeration, cryocoolers, refrigeration for space applications, cryogenic applications, cryogenic instrumentation and data acquisition, and properties of fluids. Attention is given to biomedical applications of cryogenics in China, long-term cryogen storage in space, and a passive orbital disconnect strut.

  11. Parametric performance of circumferentially grooved heat pipes with homogeneous and graded-porosity slab wicks at cryogenic temperatures. [methane and ethane working fluids

    NASA Technical Reports Server (NTRS)

    Groll, M.; Pittman, R. B.; Eninger, J. E.

    1976-01-01

    A recently developed, potentially high-performance nonarterial wick was extensively tested. This slab wick has an axially varying porosity which can be tailored to match the local stress imposed on the wick. The purpose of the tests was to establish the usefulness of the graded-porosity slab wick at cryogenic temperatures between 110 and 260 K, with methane and ethane as working fluids. For comparison, a homogeneous (i.e., uniform porosity) slab wick was also tested. The tests included: maximum heat pipe performance as a function of fluid inventory, maximum performance as a function of operating temperature, maximum performance as a function of evaporator elevation, and influence of slab wick orientation on performance. The experimental data were compared with theoretical predictions obtained with the GRADE computer program.

  12. CRYOGENIC DEWAR

    DOEpatents

    Chamberlain, W.H.; Maseck, H.E.

    1964-01-28

    This patent relates to a dewar for storing cryogenic gase and is of the type having aii inner flask surrounded by a vacuum jacket and having a vent spout through which evaporating gas escapes. Heretofore substantial gas loss has resulted from the radiation of heat towards the flask from the warmer outer elements of the dewar. In this invention, the mask is surrounded by a thermally conducting shield which is disposed in the vacuum space between the flask and the outer elements of the dewar. The shield contacts only the vent spout, which is cooled by the evaporating gas, and thus is maintained at a temperature very close to that of the flask itself. Accordingly, heat radiated toward the flask is intercepted and conducted to the evaporating gas rather than being re-radiated towards the hask. In a liquid helium dewar of typical configniration the mention reduces the boil-off rate by approximately one-half.(AEC)

  13. Cryogenic processes and equipment - 1984; Proceedings of the Fifth Intersociety Cryogenics Symposium, New Orleans, LA, December 9-14, 1984

    NASA Astrophysics Data System (ADS)

    Kerney, P. J.; Chatterjee, N.; Crawford, D. B.; El-Masri, M.

    The topics of cryogenic processes for LNG and EOR, cryogenic refrigerators, components for cryogenic systems, liquid hydrogen as a fuel, cryogenic processes and equipment for large systems, and cryogenic thermodynamics and heat transfer are discussed. The papers include analysis of process efficiency for baseload LNG production, process efficiency considerations for nitrogen rejection units, design and performance analysis of gas sorption compressors, cryogenic vacuum pump design, and the hydrogen-fueled hydrogen transport rail system (a NASA proposal). In addition, refueling considerations for liquid hydrogen-fueled vehicles, variable oxygen supply systems, and orientation dependence to liquid helium heat transfer from a cable-in-channel configuration are considered.

  14. EOL performance comparison of GaAs/Ge and Si BSF/R solar arrays

    NASA Technical Reports Server (NTRS)

    Woike, Thomas J.

    1993-01-01

    EOL power estimates for solar array designs are significantly influenced by the predicted degradation due to charged particle radiation. New radiation-induced power degradation data for GaAs/Ge solar arrays applicable to missions ranging from low earth orbit (LEO) to geosynchronous earth orbit (GEO) and compares these results to silicon BSF/R arrays. These results are based on recently published radiation damage coefficients for GaAs/Ge cells. The power density ratio (GaAs/Ge to Si BSF/R) was found to be as high as 1.83 for the proton-dominated worst-case altitude of 7408 km medium Earth orbit (MEO). Based on the EOL GaAs/Ge solar array power density results for MEO, missions which were previously considered infeasible may be reviewed based on these more favorable results. The additional life afforded by using GaAs/Ge cells is an important factor in system-level trade studies when selecting a solar cell technology for a mission and needs to be considered. The data presented supports this decision since the selected orbits have characteristics similar to most orbits of interest.

  15. Performance of the 0.3-meter transonic cryogenic tunnel with air, nitrogen, and sulfur hexafluoride media under closed loop automatic control

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.; Kilgore, W. Allen

    1995-01-01

    The NASA Langley 0.3-m Transonic Cryogenic Tunnel was modified in 1994, to operate with any one of the three test gas media viz., air, cryogenic nitrogen gas, or sulfur hexafluoride gas. This document provides the initial test results with respect to the tunnel performance and tunnel control, as a part of the commissioning activities on the microcomputer based controller. The tunnel can provide precise and stable control of temperature to less than or equal to +/- 0.3 K in the range 80-320 K in cyro mode or 300-320 K in air/SF6 mode, pressure to +/- 0.01 psia in the range 15-88 psia and Mach number to +/- O.0015 in the range 0.150 to transonic Mach numbers up to 1.000. A new heat exchanger has been included in the tunnel circuit and is performing adequately. The tunnel airfoil testing benefits considerably by precise control of tunnel states and helps in generating high quality aerodynamic test data from the 0.3-m TCT.

  16. Thermal performance of an integrated thermal protection system for long-term storage of cryogenic propellants in space

    NASA Technical Reports Server (NTRS)

    Dewitt, R. L.; Boyle, R. J.

    1977-01-01

    It was demonstrated that cryogenic propellants can be stored unvented in space long enough to accomplish a Saturn orbiter mission after 1,200-day coast. The thermal design of a hydrogen-fluorine rocket stage was carried out, and the hydrogen tank, its support structure, and thermal protection system were tested in a vacuum chamber. Heat transfer rates of approximately 23 W were measured in tests to simulate the near-Earth portion of the mission. Tests to simulate the majority of the time the vehicle would be in deep space and sun-oriented resulted in a heat transfer rate of 0.11 W.

  17. Performance of First C100 Cryomodules for the CEBAF 12 GeV Upgrade Project

    SciTech Connect

    Drury, Michael A.; Burrill, Andrew B.; Davis, G. Kirk; Hogan, John P.; King, Lawrence; Marhauser, Frank; Park, HyeKyoung; Preble, Joseph; Reece, Charles E.; Reilly, Anthony V.; Rimmer, Robert A.; Wang, Haipeng; Wiseman, Mark A.

    2012-09-01

    The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the project is a doubling of the available beam energy of CEBAF from 6 GeV to 12 GeV. This increase in beam energy will be due primarily to the construction and installation of ten "C100" cryomodules in the CEBAF linacs. The C100 cryomodules are designed to deliver an average 108 MV each from a string of eight seven-cell, electropolished superconducting RF cavities operating at an average accelerating gradient of 19.2 MV/m. The new cryomodules fit in the same available linac space as the original CEBAF 20 MV cryomodules. Cryomodule production started in September 2010. Initial acceptance testing started in June 2011. The first two C100 cryomodules were installed and tested from August 2011 through October 2011, and successfully operated during the last period of the CEBAF 6 GeV era, which ended in May 2012. This paper will present the results of acceptance testing and commissioning of the C100 style cryomodules to date.

  18. An HEMT-Based Cryogenic Charge Amplifier for Sub-kelvin Semiconductor Radiation Detectors

    NASA Astrophysics Data System (ADS)

    Phipps, A.; Sadoulet, B.; Juillard, A.; Jin, Y.

    2016-07-01

    We present the design and noise performance of a fully cryogenic (T=4 K) high-electron mobility transistor (HEMT)-based charge amplifier for readout of sub-kelvin semiconductor radiation detectors. The amplifier is being developed for use in direct detection dark matter searches such as the cryogenic dark matter search and will allow these experiments to probe weakly interacting massive particle masses below 10 GeV/c^2 while retaining background discrimination. The amplifier dissipates ≈ 1 mW of power and provides an open loop voltage gain of several hundreds. The measured noise performance is better than that of JFET-based charge amplifiers and is dominated by the noise of the input HEMT. An optimal filter calculation using the measured closed loop noise and typical detector characteristics predicts a charge resolution of σ _q=106 eV (35 electrons) for leakage currents below 4 × 10^{-15} A.

  19. Numerical analysis of the static performance of an annular aerostatic gas thrust bearing applied in the cryogenic turbo-expander of the EAST subsystem

    NASA Astrophysics Data System (ADS)

    Tianwei, LAI; Bao, FU; Shuangtao, CHEN; Qiyong, ZHANG; Yu, HOU

    2017-02-01

    The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust bearing. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.

  20. Development and Performance of Detectors for the Cryogenic Dark Matter Search Experiment with an Increased Sensitivity Based on a Maximum Likelihood Analysis of Beta Contamination

    SciTech Connect

    Driscoll, Donald D

    2004-05-01

    The Cryogenic Dark Matter Search (CDMS) uses cryogenically-cooled detectors made of germanium and silicon in an attempt to detect dark matter in the form of Weakly-Interacting Massive Particles (WIMPs). The expected interaction rate of these particles is on the order of 1/kg/day, far below the 200/kg/day expected rate of background interactions after passive shielding and an active cosmic ray muon veto. Our detectors are instrumented to make a simultaneous measurement of both the ionization energy and thermal energy deposited by the interaction of a particle with the crystal substrate. A comparison of these two quantities allows for the rejection of a background of electromagnetically-interacting particles at a level of better than 99.9%. The dominant remaining background at a depth of ~ 11 m below the surface comes from fast neutrons produced by cosmic ray muons interacting in the rock surrounding the experiment. Contamination of our detectors by a beta emitter can add an unknown source of unrejected background. In the energy range of interest for a WIMP study, electrons will have a short penetration depth and preferentially interact near the surface. Some of the ionization signal can be lost to the charge contacts there and a decreased ionization signal relative to the thermal signal will cause a background event which interacts at the surface to be misidentified as a signal event. We can use information about the shape of the thermal signal pulse to discriminate against these surface events. Using a subset of our calibration set which contains a large fraction of electron events, we can characterize the expected behavior of surface events and construct a cut to remove them from our candidate signal events. This thesis describes the development of the 6 detectors (4 x 250 g Ge and 2 x 100 g Si) used in the 2001-2002 CDMS data run at the Stanford Underground Facility with a total of 119 livedays of data. The preliminary results presented are based on the first use

  1. Improving the opto-microwave performance of SiGe/Si phototransistor through edge-illuminated structure

    NASA Astrophysics Data System (ADS)

    Tegegne, Z. G.; Viana, C.; Polleux, J. L.; Grzeskowiak, M.; Richalot, E.

    2016-03-01

    This paper demonstrates the experimental study of edge and top illuminated SiGe phototransistors (HPT) implemented using the existing industrial SiGe2RF Telefunken GmbH BiCMOS technology for opto-microwave (OM) applications using 850nm Multi-Mode Fibers (MMF). Its technology and structure are described. Two different optical window size HPTs with top illumination (5x5μm2, 10x10μm2) and an edge illuminated HPTs having 5μm x5μm size are presented and compared. A two-step post fabrication process was used to create an optical access on the edge of the HPT for lateral illumination with a lensed MMF through simple polishing and dicing techniques. We perform Opto-microwave Scanning Near-field Optical Microscopy (OM-SNOM) analysis on edge and top illuminated HPTs in order to observe the fastest and the highest sensitive regions of the HPTs. This analysis also allows understanding the parasitic effect from the substrate, and thus draws a conclusion on the design aspect of SiGe/Si HPT. A low frequency OM responsivity of 0.45A/W and a cutoff frequency, f-3dB, of 890MHz were measured for edge illuminated HPT. Compared to the top illuminated HPT of the same size, the edge illuminated HPT improves the f-3dB by a factor of more than two and also improves the low frequency responsivity by a factor of more than four. These results demonstrate that a simple etched HPT is still enough to achieve performance improvements compared to the top illuminated HPT without requiring a complex coupling structure. Indeed, it also proves the potential of edge coupled SiGe HPT in the ultra-low-cost silicon based optoelectronics circuits with a new approach of the optical packaging and system integration to 850nm MMF.

  2. Catalyst engineering for lithium ion batteries: the catalytic role of Ge in enhancing the electrochemical performance of SnO2(GeO2)0.13/G anodes

    NASA Astrophysics Data System (ADS)

    Zhu, Yun Guang; Wang, Ye; Han, Zhao Jun; Shi, Yumeng; Wong, Jen It; Huang, Zhi Xiang; Ostrikov, Kostya Ken; Yang, Hui Ying

    2014-11-01

    The catalytic role of germanium (Ge) was investigated to improve the electrochemical performance of tin dioxide grown on graphene (SnO2/G) nanocomposites as an anode material of lithium ion batteries (LIBs). Germanium dioxide (GeO2) and SnO2 nanoparticles (<10 nm) were uniformly anchored on the graphene sheets via a simple single-step hydrothermal method. The synthesized SnO2(GeO2)0.13/G nanocomposites can deliver a capacity of 1200 mA h g-1 at a current density of 100 mA g-1, which is much higher than the traditional theoretical specific capacity of such nanocomposites (~702 mA h g-1). More importantly, the SnO2(GeO2)0.13/G nanocomposites exhibited an improved rate, large current capability (885 mA h g-1 at a discharge current of 2000 mA g-1) and excellent long cycling stability (almost 100% retention after 600 cycles). The enhanced electrochemical performance was attributed to the catalytic effect of Ge, which enabled the reversible reaction of metals (Sn and Ge) to metals oxide (SnO2 and GeO2) during the charge/discharge processes. Our demonstrated approach towards nanocomposite catalyst engineering opens new avenues for next-generation high-performance rechargeable Li-ion batteries anode materials.The catalytic role of germanium (Ge) was investigated to improve the electrochemical performance of tin dioxide grown on graphene (SnO2/G) nanocomposites as an anode material of lithium ion batteries (LIBs). Germanium dioxide (GeO2) and SnO2 nanoparticles (<10 nm) were uniformly anchored on the graphene sheets via a simple single-step hydrothermal method. The synthesized SnO2(GeO2)0.13/G nanocomposites can deliver a capacity of 1200 mA h g-1 at a current density of 100 mA g-1, which is much higher than the traditional theoretical specific capacity of such nanocomposites (~702 mA h g-1). More importantly, the SnO2(GeO2)0.13/G nanocomposites exhibited an improved rate, large current capability (885 mA h g-1 at a discharge current of 2000 mA g-1) and excellent long

  3. Energy Efficient Cryogenics

    NASA Technical Reports Server (NTRS)

    Meneghelli, Barry J.; Notardonato, William; Fesmire, James E.

    2016-01-01

    The Cryogenics Test Laboratory, NASA Kennedy Space Center, works to provide practical solutions to low-temperature problems while focusing on long-term technology targets for the energy-efficient use of cryogenics on Earth and in space.

  4. Nuclear Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced NEP.

  5. Cryogenic insulation development

    NASA Technical Reports Server (NTRS)

    Leonhard, K. E.

    1972-01-01

    Multilayer insulations for long term cryogenic storage are described. The development effort resulted in an insulation concept using lightweight radiation shields, separated by low conductive Dacron fiber tufts. The insulation is usually referred to as Superfloc. The fiber tufts are arranged in a triangular pattern and stand about .040 in. above the radiation shield base. Thermal and structural evaluation of Superfloc indicated that this material is a strong candidate for the development of high performance thermal protection systems because of its high strength, purge gas evacuation capability during boost, its density control and easy application to a tank.

  6. Performance of the e2v 1.2 GPix cryogenic camera for the J-PAS 2.5m survey telescope

    NASA Astrophysics Data System (ADS)

    Robbins, M. S.; Bastable, M.; Bates, A.; Dryer, M.; Eames, S.; Fenemore-Jones, G.; Haddow, G.; Jorden, P. R.; Lane, B.; Marin-Franch, A.; Mortimer, J.; Palmer, I.; Puttay, N.; Renshaw, R.; Smith, M.; Taylor, K.; Tearle, J.; Weston, P.; Wheeler, P.; Worley, J.

    2016-08-01

    The J-PAS project will perform a five-year survey of the northern sky from a new 2.5m telescope in Teruel, Spain. In this paper the build and factory testing of the commercially supplied cryogenic camera is described. The 1.2 Giga-pixel focal plane is contained within a novel liquid-nitrogen cooled vacuum cryostat, which maintains the flatness for the cooled, 0.45m diameter focal plane to better than 27 μm peak to valley. The cooling system controls the focal plane to a temperature of -100°C with a variation across the focal plane of better than 2.5oC and a stability of better than +/- 0.5 °C over the long periods of operation required. The proximity drive electronics achieves total system level noise performance better than 5 e- from the 224-channel CCD system.

  7. Collapsible Cryogenic Storage Vessel Project

    NASA Technical Reports Server (NTRS)

    Fleming, David C.

    2002-01-01

    Collapsible cryogenic storage vessels may be useful for future space exploration missions by providing long-term storage capability using a lightweight system that can be compactly packaged for launch. Previous development efforts have identified an 'inflatable' concept as most promising. In the inflatable tank concept, the cryogen is contained within a flexible pressure wall comprised of a flexible bladder to contain the cryogen and a fabric reinforcement layer for structural strength. A flexible, high-performance insulation jacket surrounds the vessel. The weight of the tank and the cryogen is supported by rigid support structures. This design concept is developed through physical testing of a scaled pressure wall, and through development of tests for a flexible Layered Composite Insulation (LCI) insulation jacket. A demonstration pressure wall is fabricated using Spectra fabric for reinforcement, and burst tested under noncryogenic conditions. An insulation test specimens is prepared to demonstrate the effectiveness of the insulation when subject to folding effects, and to examine the effect of compression of the insulation under compressive loading to simulate the pressure effect in a nonrigid insulation blanket under the action atmospheric pressure, such as would be seen in application on the surface of Mars. Although pressure testing did not meet the design goals, the concept shows promise for the design. The testing program provides direction for future development of the collapsible cryogenic vessel concept.

  8. Cryogenic Technology for Superconducting Accelerators

    NASA Astrophysics Data System (ADS)

    Hosoyama, Kenji

    2012-01-01

    Superconducting devices such as magnets and cavities are key components in the accelerator field for increasing the beam energy and intensity, and at the same time making the system compact and saving on power consumption in operation. An effective cryogenic system is required to cool and keep the superconducting devices in the superconducting state stably and economically. The helium refrigeration system for application to accelerators will be discussed in this review article. The concept of two cooling modes -- the liquefier and refrigerator modes -- will be discussed in detail because of its importance for realizing efficient cooling and stable operation of the system. As an example of the practical cryogenic system, the TRISTAN cryogenic system of KEK Laboratory will be treated in detail and the main components of the cryogenic system, including the high-performance multichannel transfer line and liquid nitrogen circulation system at 80K, will also be discussed. In addition, we will discuss the operation of the cryogenic system, including the quench control and safety of the system. The satellite refrigeration system will be discussed because of its potential for wide application in medium-size accelerators and in industry.

  9. Cryogenic immersion microscope

    SciTech Connect

    Le Gros, Mark; Larabell, Carolyn A.

    2010-12-14

    A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

  10. Effect of GeO2 on the lasing performance of Yb: Phosphate glass fiber

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Wang, Yajie; Zhang, Liyan; Chen, Danping

    2017-02-01

    A novel GeO2 modified Yb: phosphate glass with good luminescent properties has been demonstrated. P and PG fibers were fabricated by the stack-and-draw method. An output power of 6.4 W with slope efficiency of 46% was obtained from 40.5 cm long PG fiber, while 40.2 cm long P fiber had an output power of 2.7 W and 34% slope efficiency.

  11. Dispersion of nanodiamond on chemical mechanical polishing performance for Ge1Sb6Te3 film.

    PubMed

    Yang, Il-Ho; Song, Min-Jung; Shin, Dong-Hee; Lee, Seung-Koo; Hwang, Eung-Rim; Lim, Dae-Soon

    2013-09-01

    This study describes the effect of surfactant concentration on the chemical mechanical polishing process of Ge1Sb6Te3 film using nanodiamond-based slurry. Aggregated diamond nanoparticles were dispersed in a slurry solution containing anionic poly(sodium 4-styrene sulfonate) using milling system. The zeta-potential, particle size and transmission electron microscopy image of the dispersed nanodiamond particles were analyzed for slurries having varying surfactant concentrations to identify the effect of the surfactant concentration on the milling process. The cationic nanodiamond particles were covered with the anionic poly(sodium 4-styrene sulfonate) polymer, and the polymer acted as a dispersion agent on account of the electrostatic repulsion. By increasing the surfactant concentration in the milling process, the average particle size of the nanodiamond particle decreased until the concentration reached 0.9 wt%. In addition, the surface roughness and material removal rate of the Ge1Sb6Te3 film in the polishing process strongly-depended on the surfactant concentration. Both surface roughness and material removal rate decreased with an increase in the surfactant concentration. Excess poly(sodium 4-styrene sulfonate) acted as a passivation layer, resulting in a decrease in the surface roughness and material removal rate of the Ge1Sb6Te3 film.

  12. A piezoelectric cryogenic heat switch.

    PubMed

    Jahromi, Amir E; Sullivan, Dan F

    2014-06-01

    We have measured the thermal conductance of a mechanical heat switch actuated by a piezoelectric positioner, the PZHS (PieZo electric Heat Switch), at cryogenic temperatures. The thermal conductance of the PZHS was measured between 4 K and 10 K, and on/off conductance ratios of about 100-200 at lowest and highest measures temperature were achieved when the positioner applied its maximum force of 8 N, respectively. We discuss the advantages of using this system in cryogenic applications, and estimate the ultimate performance of an ideal PZHS.

  13. Design of High Performance Si/SiGe Heterojunction Tunneling FETs with a T-Shaped Gate

    NASA Astrophysics Data System (ADS)

    Li, Wei; Liu, Hongxia; Wang, Shulong; Chen, Shupeng; Yang, Zhaonian

    2017-03-01

    In this paper, a new Si/SiGe heterojunction tunneling field-effect transistor with a T-shaped gate (HTG-TFET) is proposed and investigated by Silvaco-Atlas simulation. The two source regions of the HTG-TFET are placed on both sides of the gate to increase the tunneling area. The T-shaped gate is designed to overlap with N+ pockets in both the lateral and vertical directions, which increases the electric field and tunneling rate at the top of tunneling junctions. Moreover, using SiGe in the pocket regions leads to the smaller tunneling distance. Therefore, the proposed HTG-TFET can obtain the higher on-state current. The simulation results show that on-state current of HTG-TFET is increased by one order of magnitude compared with that of the silicon-based counterparts. The average subthreshold swing (SS) of HTG-TFET is 44.64 mV/dec when V g is varied from 0.1 to 0.4 V, and the point SS is 36.59 mV/dec at V g = 0.2 V. Besides, this design cannot bring the sever Miller capacitance for the TFET circuit design. By using the T-shaped gate and SiGe pocket regions, the overall performance of the TFET is optimized.

  14. Novel Cryogenic Insulation Materials: Aerogel Composites

    NASA Technical Reports Server (NTRS)

    White, Susan

    2001-01-01

    New insulation materials are being developed to economically and reliably insulate future reusable spacecraft cryogenic tanks over a planned lifecycle of extreme thermal challenges. These insulation materials must prevent heat loss as well as moisture and oxygen condensation on the cryogenic tanks during extended groundhold, must withstand spacecraft launch conditions, and must protect a partly full or empty reusable cryogenic tank from significant reentry heating. To perform over such an extreme temperature range, novel composites were developed from aerogels and high-temperature matrix material such as Space Shuttle tile. These materials were fabricated and tested for use both as cryogenic insulation and as high-temperature insulation. The test results given in this paper were generated during spacecraft re-entry heating simulation tests using cryogenic cooling.

  15. A study of the effects of the base doping profile on SiGe heterojunction bipolar transistor performance for all levels of injection

    NASA Astrophysics Data System (ADS)

    Khanduri, Gagan; Panwar, Brishbhan

    2006-04-01

    The effects of two different base doping profiles on the current gain and cut-off frequency for all levels of current injection have been studied for NPN Si/SiGe/Si double heterojunction bipolar transistors (SiGe DHBTs). The two-dimensional simulation results for a SiGe DHBT with uniform base doping and a fixed base Gummel number are compared with a non-uniform base doping profile SiGe drift-DHBT device. The study explains the performance of SiGe HBTs at different injection levels by analysing the electron and hole mobility, drift velocity, electric field, junction capacitances and intrinsic and extrinsic base region conductivities. The base doping profile in the SiGe drift-DHBT is controlled in such a way that it creates a net accelerating drift field in the quasi-neutral base for minority electrons. This accelerating field subsequently improves the current gain and cut-off frequency for the SiGe drift-DHBT in comparison with the SiGe DHBT for all levels of injection.

  16. High-performance Si sbnd SiGe HBTs SiGe-technology development in Esprit Project 8001 TIBIA: An overview

    NASA Astrophysics Data System (ADS)

    Terpstra, D.; De Boer, W. B.; Slotboom, J. W.

    1997-10-01

    Five major European Semiconductor Companies have cooperated on the development of technologies for the fabrication of Si sbnd SiGe-based Heterojunction Bipolar Transistors. This cooperation was part of the European Community Esprit Project 8001 TIBIA, on BICMOS Technology Development and Applications. This article presents an overview of the various concepts studied by the projet-partners, the fabrication processes and the results obtained on single devices and preliminary test-circuits (which already demonstrate the added value of Si sbnd SiGe HBTs in existing Si-technology). A more detailed description is given of the process studied at Philips, which involves double-polysilicon transistors with a selectively deposited Si sbnd SiGe base.

  17. Survey of cryogenic semiconductor devices

    SciTech Connect

    Talarico, L.J.; McKeever, J.W.

    1996-04-01

    Improved reliability and electronic performance can be achieved in a system operated at cryogenic temperatures because of the reduction in mechanical insult and in disruptive effects of thermal energy on electronic devices. Continuing discoveries of new superconductors with ever increasing values of T{sub c} above that of liquid nitrogen temperature (LNT) have provided incentive for developing semiconductor electronic systems that may also operate in the superconductor`s liquid nitrogen bath. Because of the interest in high-temperature superconductor (HTS) devices, liquid nitrogen is the cryogen of choice and LNT is the temperature on which this review is focused. The purpose of this survey is to locate and assemble published information comparing the room temperature (298 K), performance of commercially available conventional and hybrid semiconductor device with their performance at LNT (77K), to help establish their candidacy as cryogenic electronic devices specifically for use at LNT. The approach to gathering information for this survey included the following activities. Periodicals and proceedings were searched for information on the behavior of semiconductor devices at LNT. Telephone calls were made to representatives of semiconductor industries, to semiconductor subcontractors, to university faculty members prominent for their research in the area of cryogenic semiconductors, and to representatives of the National Aeronautics and Space Administration (NASA) and NASA subcontractors. The sources and contacts are listed with their responses in the introduction, and a list of references appears at the end of the survey.

  18. Method and apparatus of cryogenic cooling for high temperature superconductor devices

    DOEpatents

    Yuan, Xing; Mine, Susumu

    2005-02-15

    A method and apparatus for providing cryogenic cooling to HTS devices, in particular those that are used in high-voltage electric power applications. The method involves pressurizing liquid cryogen to above one atmospheric pressure to improve its dielectric strength, while sub-cooling the liquid cryogen to below its saturation temperature in order to improve the performance of the HTS components of the device. An apparatus utilizing such a cooling method consists of a vessel that contains a pressurized gaseous cryogen region and a sub-cooled liquid cryogen bath, a liquid cryogen heating coupled with a gaseous cryogen venting scheme to maintain the pressure of the cryogen to a value in a range that corresponds to optimum dielectric strength of the liquid cryogen, and a cooling system that maintains the liquid cryogen at a temperature below its boiling point to improve the performance of HTS materials used in the device.

  19. Magnetic performance of orthorhombic Mn35Ge35Te30 nanocrystals

    NASA Astrophysics Data System (ADS)

    Mahdy, Iman A.

    2017-01-01

    Nanocrystalline antiferromagnetic Mn35Ge35Te30 diluted magnetic semiconductors powder syntheses by the conventional direct reaction of pure metals. Nanocrystalline nature of the prepared sample confirmed using various techniques, where x-Ray diffraction (XRD) and atomic force microscope (AFM) measurements shows ~96 nm particle size, while transmission electron microscope (TEM) shows 92 nm particle size. XRD analysis show orthorhombic symmetry with lattice parameters a=7.386611±(0.0066) Å, b=8.962502±(0.0090) Å and c=7.027349±(0.0040) Å. Electron Spin resonance (ESR) show a broad asymmetric line whereas the remnant Mn2+ six-hyperfine lines are broadened within |+1/2>→|-1/2> line according to high anisotropy; calculated Landé g-factor is 2.047. Vibrating sample magnetometer (VSM) analysis, field-moment characteristics revealed a hysteresis loop with small coercive field indicating that Mn35Ge35Te30 is a soft magnetic material. Moreover, hysteresis measurements at different temperatures show increasing magnetization with increasing temperature up to 150 K followed by decreased with increasing temperature up to 300 K. This behavior indicated to the antiferromagnetic nature of the prepared nanocrystalline materials. Magnetic moment - temperature measurements show Néel temperature TN=172.6 K. Magnetic force microscope revealed magnetic domains as a result of interaction between magnetic dipole moments of magnetic cantilever and pressed powder.

  20. DC characteristics and analog/RF performance of novel polarity control GaAs-Ge based tunnel field effect transistor

    NASA Astrophysics Data System (ADS)

    Nigam, Kaushal; Kondekar, Pravin; Sharma, Dheeraj

    2016-04-01

    In this paper, for the first time, DC characteristics and analog/RF performance of polarity control GaAs-Ge hetero TFET (GaAs-Ge H-TFET) structure have been analysed, using electrically doped dynamically configurable concept. For this, we have considered a hetero structure with two distinctive gates (Control gate and Polarity gate). Polarity gate induces p+ region at the source side and n+ region at the drain side, instead of relying on the abrupt doping profile at the junctions. Therefore, the fabrication process of the proposed device avoids ion-implantation, photo masking and complicated thermal budget. Hence, it shows high immunity against process variations, doping control issues and random dopant fluctuations (RDF). In order to optimize the device performance, interfacing of III-V groups materials with IV group semiconductor is done for hetero-junction. The introduction of hetero-junction and band gap engineering offer higher ION/IOFF ratio (5.1 × 1012), steep sub-threshold slope (18 mV/decade) and significantly change in analog/RF performance. The analog/RF figures of merit are analysed in term of transconductance (gm), output conductance (gds), gate to source capacitance (Cgs), gate to drain capacitance (Cgd), cutoff frequency (fT) and gain bandwidth (GBW) product. The proposed work would be beneficial for low power high frequency applications. The simulation results presented in this paper were carried out by using 2-D ATLAS.

  1. Status of the ESS cryogenic system

    SciTech Connect

    Weisend II, J. G.; Darve, C.; Gallimore, S.; Hees, W.; Jurns, J.; Köttig, T.; Ladd, P.; Molloy, S.; Parker, T.; Wang, X. L.

    2014-01-29

    The European Spallation Source (ESS) is a neutron science facility funded by a collaboration of 17 European countries currently under design and construction in Lund, Sweden. The centerpiece of ESS is a 2.5 GeV proton linac utilizing superconducting RF cavities operating at 2 K. In addition to cooling the SRF cavities, cryogenics is also used at ESS in the liquid hydrogen moderators surrounding the target. ESS also uses both liquid helium and liquid nitrogen in a number of the planned neutron instruments. There is also a significant cryogenic installation associated with the site acceptance testing of the ESS cryomodules. The ESS cryogenic system consists of 3 separate helium refrigeration/liquefaction plants supplying the accelerator, target moderators and instruments. An extensive cryogenic distribution system connects the accelerator cryoplant with the cryomodules. This paper describes the preliminary design of the ESS cryogenic system including the expected heat loads. Challenges associated with the required high reliability and turn-down capability will also be discussed. A unique feature of ESS is its commitment to sustainability and energy recovery. A conceptual design for recovering waste heat from the helium compressors for use in the Lund district heating system will also be described.

  2. Status of the ESS cryogenic system

    NASA Astrophysics Data System (ADS)

    Weisend, J. G., II; Darve, C.; Gallimore, S.; Hees, W.; Jurns, J.; Köttig, T.; Ladd, P.; Molloy, S.; Parker, T.; Wang, X. L.

    2014-01-01

    The European Spallation Source (ESS) is a neutron science facility funded by a collaboration of 17 European countries currently under design and construction in Lund, Sweden. The centerpiece of ESS is a 2.5 GeV proton linac utilizing superconducting RF cavities operating at 2 K. In addition to cooling the SRF cavities, cryogenics is also used at ESS in the liquid hydrogen moderators surrounding the target. ESS also uses both liquid helium and liquid nitrogen in a number of the planned neutron instruments. There is also a significant cryogenic installation associated with the site acceptance testing of the ESS cryomodules. The ESS cryogenic system consists of 3 separate helium refrigeration/liquefaction plants supplying the accelerator, target moderators and instruments. An extensive cryogenic distribution system connects the accelerator cryoplant with the cryomodules. This paper describes the preliminary design of the ESS cryogenic system including the expected heat loads. Challenges associated with the required high reliability and turn-down capability will also be discussed. A unique feature of ESS is its commitment to sustainability and energy recovery. A conceptual design for recovering waste heat from the helium compressors for use in the Lund district heating system will also be described.

  3. Examination of the temperature dependent electronic behavior of GeTe for switching applications

    NASA Astrophysics Data System (ADS)

    Champlain, James G.; Ruppalt, Laura B.; Guyette, Andrew C.; El-Hinnawy, Nabil; Borodulin, Pavel; Jones, Evan; Young, Robert M.; Nichols, Doyle

    2016-06-01

    The DC and RF electronic behaviors of GeTe-based phase change material switches as a function of temperature, from 25 K to 375 K, have been examined. In its polycrystalline (ON) state, GeTe behaved as a degenerate p-type semiconductor, exhibiting metal-like temperature dependence in the DC regime. This was consistent with the polycrystalline (ON) state RF performance of the switch, which exhibited low resistance S-parameter characteristics. In its amorphous (OFF) state, the GeTe presented significantly greater DC resistance that varied considerably with bias and temperature. At low biases (<1 V) and temperatures (<200 K), the amorphous GeTe low-field resistance dramatically increased, resulting in exceptionally high amorphous-polycrystalline (OFF-ON) resistance ratios, exceeding 109 at cryogenic temperatures. At higher biases and temperatures, the amorphous GeTe exhibited nonlinear current-voltage characteristics that were best fit by a space-charge limited conduction model that incorporates the effect of a defect band. The observed conduction behavior suggests the presence of two regions of localized traps within the bandgap of the amorphous GeTe, located at approximately 0.26-0.27 eV and 0.56-0.57 eV from the valence band. Unlike the polycrystalline state, the high resistance DC behavior of amorphous GeTe does not translate to the RF switch performance; instead, a parasitic capacitance associated with the RF switch geometry dominates OFF state RF transmission.

  4. Alkanethiol-passivated ge nanowires as high-performance anode materials for lithium-ion batteries: the role of chemical surface functionalization.

    PubMed

    Yuan, Fang-Wei; Yang, Hong-Jie; Tuan, Hsing-Yu

    2012-11-27

    We demonstrate that dodecanethiol monolayer passivation can significantly enhance the anode performance of germanium (Ge) nanowires in lithium-ion batteries. The dodecanethiol-passivated Ge nanowires exhibit an excellent electrochemical performance with a reversible specific capacity of 1130 mAh/g at 0.1 C rate after 100 cycles. The functionalized Ge nanowires show high-rate capability having charge and discharge capacities of ∼555 mAh/g at high rates of 11 C. The functionalized Ge nanowires also performed well at 55 °C, showing their thermal stability at high working temperatures. Moreover, full cells using a LiFePO(4) cathode were assembled and the electrodes still have stable capacity retention. An aluminum pouch type lithium cell was also assembled to provide larger current (∼30 mA) for uses on light-emitting-diodes (LEDs) and audio devices. Investigation of the role of organic monolayer coating showed that the wires formed a robust nanowire/PVDF network through strong C-F bonding so as to maintain structure integrity during the lithiation/delithiation process. Organic monolayer-coated Ge nanowires represent promising Ge-C anodes with controllable low carbon content (ca. 2-3 wt %) for high capacity, high-rate lithium-ion batteries and are readily compatible with the commercial slurry-coating process for cell fabrication.

  5. Progress on the CUORE Cryogenic System

    SciTech Connect

    Martinez, M.; Arnaboldi, C.; Nucciotti, A.; Schaeffer, D.; Sisti, M.; Barucci, M.; Bucci, C.; Frossati, G.; De Waard, A.; Woodcraft, A.

    2009-12-16

    We give here an update on the CUORE cryogenic system. It consists of a large cryogen-free cryostat cooled by five pulse tubes and one high-power specially designed dilution refrigerator built by Leiden Cryogenics. The cryostat design has been completed and it is presently under construction. The site at the Gran Sasso Underground Laboratory is ready for the installation of the cryostat which is expected to begin by the end of 2009. We discuss here the preliminary results obtained on the performance of the mechanical cryorefrigerators. We also present a measurement of the residual heat leak of the copper which has been selected for the cryostat fabrication.

  6. Elimination of gold diffusion in the heterostructure core/shell growth of high performance Ge/Si nanowire HFETs

    SciTech Connect

    Picraux, Samuel T; Dayeh, Shadi A

    2010-01-01

    Radial heterostructure nanowires offer the possibility of surface, strain, band-edge and modulution-doped engineering for optimizing performance of nanowire transistors. Synthesis of such heterostructures is non-trivial and is typically accompanied with Au diffusion on the nanowire sidewalls that result in rough morphology and undesired whisker growth. Here, they report a novel growth procedure to synthesize Ge/Si core/multi-shell nanowires by engineering the growth interface between the Au seed and the nanowire sidewalls. Single crystal Ge/Si core/multi-shell nanowires are used to fabricate side-by-side FET transistors with and without Au diffusion. Elimination of Au diffusion in the synthesis of such structures led to {approx} 2X improvement in hole field-effect mobility, transconductances and currents. Initial prototype devices with a 10 nm PECVD nitride gate dielectric resulted in a record maximum on current of 430 {micro}A/V (I{sub DS}L{sub G}/{pi}DV{sub DS}), {approx} 2X higher than ever achieved before in a p-type FET.

  7. Lithium Germanate (Li2 GeO3 ): A High-Performance Anode Material for Lithium-Ion Batteries.

    PubMed

    Rahman, Md Mokhlesur; Sultana, Irin; Yang, Tianyu; Chen, Zhiqiang; Sharma, Neeraj; Glushenkov, Alexey M; Chen, Ying

    2016-12-23

    A simple, cost-effective, and easily scalable molten salt method for the preparation of Li2 GeO3 as a new type of high-performance anode for lithium-ion batteries is reported. The Li2 GeO3 exhibits a unique porous architecture consisting of micrometer-sized clusters (secondary particles) composed of numerous nanoparticles (primary particles) and can be used directly without further carbon coating which is a common exercise for most electrode materials. The new anode displays superior cycling stability with a retained charge capacity of 725 mAh g(-1) after 300 cycles at 50 mA g(-1) . The electrode also offers excellent rate capability with a capacity recovery of 810 mAh g(-1) (94 % retention) after 35 cycles of ascending steps of current in the range of 25-800 mA g(-1) and finally back to 25 mA g(-1) . This work emphasizes the importance of exploring new electrode materials without carbon coating as carbon-coated materials demonstrate several drawbacks in full devices. Therefore, this study provides a method and a new type of anode with high reversibility and long cycle stability.

  8. Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

    SciTech Connect

    Knudsen, P.; Ganni, V.; Dixon, K.; Norton, R.; Creel, J.

    2015-08-10

    Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which may be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.

  9. Performance Testing of Jefferson Lab 12 GeV Helium Screw Compressors

    DOE PAGES

    Knudsen, P.; Ganni, V.; Dixon, K.; ...

    2015-08-10

    Oil injected screw compressors have essentially superseded all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, reliability, minimal vibration, and capability of handling helium's high heat of compression. At the present state of compressor system designs for helium refrigeration systems, typically two-thirds of the lost input power is due to the compression system. It is important to understand the isothermal and volumetric efficiencies of these machines to help properly design the compression system to match the refrigeration process. It is also important to identify those primary compressor skid exergetic loss mechanisms which maymore » be reduced, thereby offering the possibility of significantly reducing the input power to helium refrigeration processes which are extremely energy intensive. This paper summarizes the results collected during the commissioning of the new compressor system for Jefferson Lab's (JLab's) 12 GeV upgrade. The compressor skid packages were designed by JLab and built to print by industry. They incorporate a number of modifications not typical of helium screw compressor packages and most importantly allow a very wide range of operation so that JLab's patented Floating Pressure Process can be fully utilized. This paper also summarizes key features of the skid design that allow this process and facilitate the maintenance and reliability of these helium compressor systems.« less

  10. Below-Ambient and Cryogenic Thermal Testing

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.

    2016-01-01

    Thermal insulation systems operating in below-ambient temperature conditions are inherently susceptible to moisture intrusion and vapor drive toward the cold side. The subsequent effects may include condensation, icing, cracking, corrosion, and other problems. Methods and apparatus for real-world thermal performance testing of below-ambient systems have been developed based on cryogenic boiloff calorimetry. New ASTM International standards on cryogenic testing and their extension to future standards for below-ambient testing of pipe insulation are reviewed.

  11. Linac cryogenic distribution system maintenance and upgrades at JLab

    NASA Astrophysics Data System (ADS)

    Dixon, K.; Wright, M.; Ganni, V.

    2014-01-01

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm3 of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  12. Linac cryogenic distribution system maintenance and upgrades at Jlab

    SciTech Connect

    Dixon, Kelly D.; Wright, Mathew C.; Ganni, Venkatarao

    2014-01-01

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  13. Linac cryogenic distribution system maintenance and upgrades at JLab

    SciTech Connect

    Dixon, K.; Wright, M.; Ganni, V.

    2014-01-29

    The Central Helium Liquefier (CHL) distribution system to the CEBAF and FEL linacs at Jefferson Lab (JLab) experienced a planned warm up during the late summer and fall of 2012 for the first time after its commissioning in 1991. Various maintenance and modifications were performed to support high beam availability to the experimental users, meet 10 CFR 851 requirements for pressure systems, address operational issues, and prepare the cryogenic interfaces for the high-gradient cryomodules needed for the 12 GeV upgrade. Cryogenic maintenance and installation work had to be coordinated with other activities in the linacs and compete for manpower from other department installation activities. With less than a quarter of the gas storage capacity available to handle the boil-off from the more than 40 cryomodules, 35,000 Nm{sup 3} of helium was re-liquefied and shipped to a vendor via a liquid tanker trailer. Nearly 200 u-tubes had to be removed and stored while seals were replaced on related equipment such as vacuum pump outs, bayonet isolation and process valves.

  14. Subcooling for Long Duration In-Space Cryogenic Propellant Storage

    NASA Technical Reports Server (NTRS)

    Mustafi, Shuvo; Johnson, Wesley; Kashani, Ali; Jurns, John; Kutter, Bernard; Kirk, Daniel; Shull, Jeff

    2010-01-01

    Cryogenic propellants such as hydrogen and oxygen are crucial for exploration of the solar system because of their superior specific impulse capability. Future missions may require vehicles to remain in space for months, necessitating long-term storage of these cryogens. A Thermodynamic Cryogen Subcooler (TCS) can ease the challenge of cryogenic fluid storage by removing energy from the cryogenic propellant through isobaric subcooling of the cryogen below its normal boiling point prior to launch. The isobaric subcooling of the cryogenic propellant will be performed by using a cold pressurant to maintain the tank pressure while the cryogen's temperature is simultaneously reduced using the TCS. The TCS hardware will be integrated into the launch infrastructure and there will be no significant addition to the launched dry mass. Heat leaks into all cryogenic propellant tanks, despite the use of the best insulation systems. However, the large heat capacity available in the subcooled cryogenic propellants allows the energy that leaks into the tank to be absorbed until the cryogen reaches its operational thermodynamic condition. During this period of heating of the subcooled cryogen there will be minimal loss of the propellant due to venting for pressure control. This simple technique can extend the operational life of a spacecraft or an orbital cryogenic depot for months with minimal mass penalty. In fact isobaric subcooling can more than double the in-space hold time of liquid hydrogen compared to normal boiling point hydrogen. A TCS for cryogenic propellants would thus provide an enhanced level of mission flexibility. Advances in the important components of the TCS will be discussed in this paper.

  15. Development of a cryogenic FTIR system for measuring very small attenuation coefficients of infrared materials

    NASA Astrophysics Data System (ADS)

    Kaji, Sayumi; Sarugaku, Yuki; Ikeda, Yuji; Nakanishi, Kenshi; Kobayashi, Naoto; Kondo, Sohei; Arasaki, Takayuki; Kawakita, Hideyo

    2016-07-01

    We have been working on a long-term project for developing a variety of infrared immersion gratings for near- to mid-infrared wavelengths. The transmittance of material is essential to realize high-efficiency immersion gratings for astronomical applications. For a typical grating, the attenuation coefficient αatt must be <0.01 cm-1 for the absolute diffraction efficiency of >70%. However, as there are few reports of αatt < 0.01 cm-1 for infrared optical materials in the literatures, we performed high-accuracy measurements of αatt for a variety of infrared materials applicable to immersion gratings. We have already reported αatt at room temperature for single-crystal Si, single-crystal Ge, CVD-ZnS, CVDZnSe, and high-resistivity single-crystal CdZnTe (Ikeda et al. 2009[7], Kaji et al. 2014[10], and Sarugaku et al. 2016[9]). Next, we proceeded with the measurements of αatt at cryogenic temperatures of 20-80 K range, which is the typical operational temperatures of infrared instruments, and for which the shifts of the band gap and/or the sharpness of the lattice absorption lines from the corresponding room temperature values are expected. Thus, we developed a new cryogenic FTIR system that enables high-accuracy measurements at cryogenic temperatures. The system has a mechanism with which two sample cells and a reference cell can be easily and quickly switched without any vacuum leak or temperature change. Our preliminary measurement of Ge using this cryogenic FTIR system found that both the cut-on and cut-off wavelengths shift to the shorter (from 2.0 to 1.7 μm) and longer (from 10.6 to 10.9 μm) wavelengths, respectively, when the temperature is decreased from room temperature to the cryogenic temperature (<28 K). We plan to complete cryogenic measurements for a variety of infrared materials by the end of 2016.

  16. High-performance LWIR microbolometer with Si/SiGe quantum well thermistor and wafer level packaging

    NASA Astrophysics Data System (ADS)

    Roer, Audun; Lapadatu, Adriana; Wolla, Erik; Kittilsland, Gjermund

    2013-06-01

    An uncooled microbolometer with peak responsivity in the long wave infrared region of the electromagnetic radiation is developed at Sensonor AS. It is a 384 x 288 focal plane array with a pixel pitch of 25µm, based on monocrystalline Si/SiGe quantum wells as IR sensitive material. The high sensitivity (TCR) and low 1/f-noise are the main performance characteristics of the product. The frame rate is maximum 60Hz and the output interface is digital (LVDS). The quantum well thermistor material is transferred to the read-out integrated circuit (ROIC) by direct wafer bonding. The ROIC wafer containing the released pixels is bonded in vacuum with a silicon cap wafer, providing hermetic encapsulation at low cost. The resulting wafer stack is mounted in a standard ceramic package. In this paper the architecture of the pixels and the ROIC, the wafer packaging and the electro-optical measurement results are presented.

  17. Constraints on Low-mass WIMP Signals from the Cryogenic Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Leman, Steven W.; CDMS Collaboration

    2011-09-01

    Two different, previously released, Cryogenic Dark Matter Search (CDMS) data sets have been reanalyzed to improve sensitivity to low-mass Weakly Interacting Massive Particle (WIMP) signals. The first data set was obtained from 2001 to 2002 at the shallow-depth Stanford Underground Facility (SUF) with four germanium and two silicon detectors. The second data set utilized eight germanium detectors at the deep Soudan Underground Laboratory from 2006 to 2008. The SUF data excludes parameter space between 3 and 4 GeV / c2 while the Soudan result excludes parameter space favored by the DAMA / LIBRA and CoGeNT data as light WIMP signals at the >90% confidence level. Expected performance of new detectors with an interleaved charge readout, also being commissioned at Soudan, will also be discussed.

  18. Cryogenic Flange and Seal Evaluation

    NASA Technical Reports Server (NTRS)

    Ramirez, Adrian

    2014-01-01

    The assembly of flanges, seals, and pipes are used to carry cryogenic fluid from a storage tank to the vehicle at launch sites. However, after a certain amount of cycles these raised face flanges with glass-filled Teflon gaskets have been found to have torque relaxation and are as a result susceptible to cryogenic fluid leakage if not re-torqued. The intent of this project is to identify alternate combinations of flanges and seals which may improve thermal cycle performance and decrease re-torque requirements. The general approach is to design a test fixture to evaluate leak characteristics between spiral and concentric serrations and to test alternate flange and seal combinations. Due to insufficient time, it was not possible to evaluate these different types of combinations for the combination that improved thermal cycle performance the most. However, the necessary drawings for the test fixture were designed and assembled along with the collection of the necessary parts.

  19. SCRF Cryogenic Operating Experience at FNPL

    NASA Astrophysics Data System (ADS)

    DeGraff, B.; Soyars, W.; Martinez, A.

    2006-04-01

    The Fermilab-NICADD Photoinjector Laboratory (FNPL), a photoelectron research and development beam line, has been operational since 1998. A single TESLA 9-cell superconducting RF cavity is operated in support of this accelerator system. The superfluid cryogenic system consists of a dewar-fed liquid helium supply with up to 2 g/s vacuum pumping capacity. Helium gas is recovered to the Tevatron cryogenic system. The photoinjector static load is about 2.5 W to 1.8 K, with a typical dynamic component of about 0.5 W. The capabilities, performance, operating experience, and reliability of this superfluid cryogenic system will be discussed. An auxiliary cryogenic system for testing bare superconducting RF cavities in a vertical dewar is also available, providing a steady state capacity of about 12 W at 1.8 K for testing.

  20. The cryogenic wind tunnel

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1976-01-01

    Based on theoretical studies and experience with a low speed cryogenic tunnel and with a 1/3-meter transonic cryogenic tunnel, the cryogenic wind tunnel concept was shown to offer many advantages with respect to the attainment of full scale Reynolds number at reasonable levels of dynamic pressure in a ground based facility. The unique modes of operation available in a pressurized cryogenic tunnel make possible for the first time the separation of Mach number, Reynolds number, and aeroelastic effects. By reducing the drive-power requirements to a level where a conventional fan drive system may be used, the cryogenic concept makes possible a tunnel with high productivity and run times sufficiently long to allow for all types of tests at reduced capital costs and, for equal amounts of testing, reduced total energy consumption in comparison with other tunnel concepts.

  1. Characterisation of diode-connected SiGe BiCMOS HBTs for space applications

    NASA Astrophysics Data System (ADS)

    Venter, Johan; Sinha, Saurabh; Lambrechts, Wynand

    2016-02-01

    Silicon-germanium (SiGe) bipolar complementary metal-oxide semiconductor (BiCMOS) transistors have vertical doping profiles reaching deeper into the substrate when compared to lateral CMOS transistors. Apart from benefiting from high-speed, high current gain and low-output resistance due to its vertical profile, BiCMOS technology is increasingly becoming a preferred technology for researchers to realise next-generation space-based optoelectronic applications. BiCMOS transistors have inherent radiation hardening, to an extent predictable cryogenic performance and monolithic integration potential. SiGe BiCMOS transistors and p-n junction diodes have been researched and used as a primary active component for over the last two decades. However, further research can be conducted with diode-connected heterojunction bipolar transistors (HBTs) operating at cryogenic temperatures. This work investigates these characteristics and models devices by adapting standard fabrication technology components. This work focuses on measurements of the current-voltage relationship (I-V curves) and capacitance-voltage relationships (C-V curves) of diode-connected HBTs. One configuration is proposed and measured, which is emitterbase shorted. The I-V curves are measured for various temperature points ranging from room temperature (300 K) to the temperature of liquid nitrogen (77 K). The measured datasets are used to extract a model of the formed diode operating at cryogenic temperatures and used as a standard library component in computer aided software designs. The advantage of having broad-range temperature models of SiGe transistors becomes apparent when considering implementation of application-specific integrated circuits and silicon-based infrared radiation photodetectors on a single wafer, thus shortening interconnects and lowering parasitic interference, decreasing the overall die size and improving on overall cost-effectiveness. Primary applications include space-based geothermal

  2. A cryogenic receiver for EPR.

    PubMed

    Narkowicz, R; Ogata, H; Reijerse, E; Suter, D

    2013-12-01

    Cryogenic probes have significantly increased the sensitivity of NMR. Here, we present a compact EPR receiver design capable of cryogenic operation. Compared to room temperature operation, it reduces the noise by a factor of ≈2.5. We discuss in detail the design and analyze the resulting noise performance. At low microwave power, the input noise density closely follows the emission of a cooled 50Ω resistor over the whole measurement range from 20K up to room temperature. To minimize the influence of the microwave source noise, we use high microwave efficiency (≈1.1-1.7mTW(-1/2)) planar microresonators. Their efficient conversion of microwave power to magnetic field permits EPR measurements with very low power levels, typically ranging from a few μW down to fractions of nW.

  3. ZERODUR TAILORED for cryogenic application

    NASA Astrophysics Data System (ADS)

    Jedamzik, R.; Westerhoff, T.

    2014-07-01

    ZERODUR® glass ceramic from SCHOTT is known for its very low thermal expansion coefficient (CTE) at room temperature and its excellent CTE homogeneity. It is widely used for ground-based astronomical mirrors but also for satellite applications. Many reference application demonstrate the excellent and long lasting performance of ZERODUR® components in orbit. For space application a low CTE of the mirror material is required at cryogenic temperatures together with a good match of the thermal expansion to the supporting structure material. It is possible to optimize the coefficient of thermal expansion of ZERODUR® for cryogenic applications. This paper reports on measurements of thermal expansion of ZERODUR® down to cryogenic temperatures of 10 K performed by the PTB (Physikalisch Technische Bundesanstallt, Braunschweig, Germany, the national metrology laboratory). The ZERODUR® TAILORED CRYO presented in this paper has a very low coefficient of thermal expansion down to 70 K. The maximum absolute integrated thermal expansion down to 10 K is only about 20 ppm. Mirror blanks made from ZERODUR® TAILORED CRYO can be light weighted to almost 90% with our modern processing technologies. With ZERODUR® TAILORED CRYO, SCHOTT offers the mirror blank material for the next generation of space telescope applications.

  4. Usaf Space Sensing Cryogenic Considerations

    NASA Astrophysics Data System (ADS)

    Roush, F.

    2010-04-01

    Infrared (IR) space sensing missions of the future depend upon low mass components and highly capable imaging technologies. Limitations in visible imaging due to the earth's shadow drive the use of IR surveillance methods for a wide variety of applications for Intelligence, Surveillance, and Reconnaissance (ISR), Ballistic Missile Defense (BMD) applications, and almost certainly in Space Situational Awareness (SSA) and Operationally Responsive Space (ORS) missions. Utilization of IR sensors greatly expands and improves mission capabilities including target and target behavioral discrimination. Background IR emissions and electronic noise that is inherently present in Focal Plane Arrays (FPAs) and surveillance optics bench designs prevents their use unless they are cooled to cryogenic temperatures. This paper describes the role of cryogenic coolers as an enabling technology for generic ISR and BMD missions and provides ISR and BMD mission and requirement planners with a brief glimpse of this critical technology implementation potential. The interaction between cryogenic refrigeration component performance and the IR sensor optics and FPA can be seen as not only mission enabling but also as mission performance enhancing when the refrigeration system is considered as part of an overall optimization problem.

  5. Cryogenic Pound Circuits for Cryogenic Sapphire Oscillators

    NASA Technical Reports Server (NTRS)

    Dick, G. John; Wang, Rabi

    2006-01-01

    Two modern cryogenic variants of the Pound circuit have been devised to increase the frequency stability of microwave oscillators that include cryogenic sapphire-filled cavity resonators. The original Pound circuit is a microwave frequency discriminator that provides feedback to stabilize a voltage-controlled microwave oscillator with respect to an associated cavity resonator. In the present cryogenic Pound circuits, the active microwave devices are implemented by use of state-of-the-art commercially available tunnel diodes that exhibit low flicker noise (required for high frequency stability) and function well at low temperatures and at frequencies up to several tens of gigahertz. While tunnel diodes are inherently operable as amplitude detectors and amplitude modulators, they cannot, by themselves, induce significant phase modulation. Therefore, each of the present cryogenic Pound circuits includes passive circuitry that transforms the AM into the required PM. Each circuit also contains an AM detector that is used to sample the microwave signal at the input terminal of the high-Q resonator for the purpose of verifying the desired AM null at this point. Finally, each circuit contains a Pound signal detector that puts out a signal, at the modulation frequency, having an amplitude proportional to the frequency error in the input signal. High frequency stability is obtained by processing this output signal into feedback to a voltage-controlled oscillator to continuously correct the frequency error in the input signal.

  6. A computer algorithm for performing interactive algebraic computation on the GE Image-100 system

    NASA Technical Reports Server (NTRS)

    Hart, W. D.; Kim, H. H.

    1979-01-01

    A subroutine which performs specialized algebraic computations upon ocean color scanner multispectral data is presented. The computed results are displayed on a video display. The subroutine exists as a component of the aircraft sensor analysis package. The user specifies the parameters of the computations by directly interacting with the computer. A description of the conversational options is also given.

  7. Feasibility study for the Cryogenic Orbital Nitrogen Experiment (CONE)

    NASA Technical Reports Server (NTRS)

    Bell, R. S.; Crouch, M. A.; Hanna, G. J.; Cady, E. C.; Meserole, J. S.

    1991-01-01

    An improved understanding of low gravity subcritical cryogenic fluid behavior is critical for the continued development of space based systems. Although early experimental programs provided some fundamental understanding of zero gravity cryogenic fluid behavior, more extensive flight data are required to design space based cryogenic liquid storage and transfer systems with confidence. As NASA's mission concepts evolve, the demand for optimized in-space cryogenic systems is increasing. Cryogenic Orbital Nitrogen Experiment (CONE) is an attached shuttle payload experiment designed to address major technological issues associated with on-orbit storage and supply of cryogenic liquids. During its 7 day mission, CONE will conduct experiments and technology demonstrations in active and passive pressure control, stratification and mixing, liquid delivery and expulsion efficiency, and pressurant bottle recharge. These experiments, conducted with liquid nitrogen as the test fluid, will substantially extend the existing low gravity fluid data base and will provide future system designers with vital performance data from an orbital environment.

  8. Impact of the Cryogen Free Revolution on Neutron Scattering Laboratories

    NASA Astrophysics Data System (ADS)

    Kirichek, Oleg

    A global shortage of helium gas can seriously jeopardise the scientific programmes of neutron scattering laboratories due to the use of cryogenic sample environment in the majority of the neutron scattering experiments. Recently developed cryogen-free technology allows a significant reduction or even a complete elimination of liquid helium consumption. Here we review the impact of the cryogen-free revolution on cryogenic equipment used at large neutron facilities, such as cryostats, dilution refrigerators, superconducting magnets and other cryogenic systems. Particular attention is given to the newly developed superconducting magnets for neutron diffraction and spectroscopy experiments. Use of the cryogen-free approach, as well as cutting-edge superconducting magnet technology and advanced neutron optics allows researcher to achieve extraordinary performance in their experiments, opening up new opportunities in neutron scattering research.

  9. SNS Cryogenic Systems Commissioning

    SciTech Connect

    D. Hatfield; F. Casagrande; I. Campisi; P. Gurd; M. Howell; D. Stout; H. Strong; D. Arenius; J. Creel; K. Dixon; V. Ganni; and P. Knudsen

    2005-08-29

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  10. SNS Cryogenic Systems Commissioning

    NASA Astrophysics Data System (ADS)

    Hatfield, D.; Casagrande, F.; Campisi, I.; Gurd, P.; Howell, M.; Stout, D.; Strong, H.; Arenius, D.; Creel, J.; Dixon, K.; Ganni, V.; Knudsen, P.

    2006-04-01

    The Spallation Neutron Source (SNS) is under construction at Oak Ridge National Laboratory. The cold section of the Linac consists of 81 superconducting radio frequency cavities cooled to 2.1K by a 2400 watt cryogenic refrigeration system. The major cryogenic system components include warm helium compressors with associated oil removal and gas management, 4.5K cold box, 7000L liquid helium dewar, 2.1K cold box (consisting of 4 stages of cold compressors), gaseous helium storage, helium purification and gas impurity monitoring system, liquid nitrogen storage and the cryogenic distribution transfer line system. The overall system commissioning and future plans will be presented.

  11. RHIC Performance as a 100 GeV Polarized Proton Collider in Run-9

    SciTech Connect

    Montag, C.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Connolly, R.; DOttavio, T.; Drees, A.; Fedotov, A.V.; Fischer, W.; Ganetis, G.; Gardner, C.; Glenn, J.; Hahn, H.; Harvey, M.; Hayes, T.; Huang, H.; Ingrassia, P.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Lee, R.C.; Luccio, A.U.; Luo, Y.; MacKay, W.W.; Makdisi, Y.; Malitsky, N.; Marr, G.; Marusic, A.; Menga, P.M.; Michnoff, R.; Minty, M.; Morris, J.; Oerter, B.; Pilat, F.; Pile, P.; Pozdeyev, E.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Satogata, T.; Schoefer, V.; Schultheiss, C.; Severino, F.; Sivertz, M.; Smith, K.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Zaltsman, A.; Zelenski, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    During the second half of Run-9, the Relativisitc Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points. The spin orientation of both beams at these collision points was controlled by helical spin rotators, and physics data were taken with different orientations of the beam polarization. Recent developments and improvements will be presented, as well as luminosity and polarization performance achieved during Run-9.

  12. Cryogenic optical tests of a lightweight HIP beryllium mirror

    NASA Technical Reports Server (NTRS)

    Melugin, Ramsey K.; Miller, Jacob H.; Young, J. A.; Howard, Steven D.; Pryor, G. Mark

    1989-01-01

    Five interferometric tests were conducted at cryogenic temperatures on a lightweight, 50 cm diameter, hot isostatic pressed (HIP) beryllium mirror in the Ames Research Center (ARC) Cryogenic Optics Test Facility. The purpose of the tests was to determine the stability of the mirror's figure when cooled to cryogenic temperatures. Test temperatures ranged from room ambient to 8 K. One cycle to 8 K and five cycles to 80 K were performed. Optical and thermal test methods are described. Data is presented to show the amount of cryogenic distortion and hysteresis present in the mirror when measured with an earlier, Shack interferometer, and with a newly-acquired, phase-measuring interferometer.

  13. Cryopumping in Cryogenic Insulations for a Reusable Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Johnson, Theodore F.; Weiser, Erik S.; Grimsley, Brian W.; Jensen, Brian J.

    2003-01-01

    Testing at cryogenic temperatures was performed to verify the material characteristics and manufacturing processes of reusable propellant tank cryogenic insulations for a Reusable Launch Vehicle (RLV). The unique test apparatus and test methods developed for the investigation of cryopumping in cryogenic insulations are described. Panel level test specimens with various types of cryogenic insulations were subjected to a specific thermal profile where the temperature varied from -262 C to 21 C. Cryopumping occurred if the interior temperature of the specimen exhibited abnormal temperature fluctuations, such as a sudden decrease in temperature during the heating phase.

  14. An Experimental Platform for Performing Measurements of the RF Magnetic Permeability and Electric Permittivity of Functional Materials at Cryogenic Temperatures

    DTIC Science & Technology

    2013-09-01

    research into a class of electronics based on modifying superconducting circuitry through the integration of complex functional materials with...governing the superconducting tunneling properties can assume frequency-dependent behavior. The interfacing of multi- ferroic and superconducting ...characteristic performance of various types of superconducting circuit structures. This could potentially enable high-precision dynamic control of

  15. Advances in cryogenic engineering. Volume 29 - Proceedings of the Cryogenic Engineering Conference, Colorado Springs, CO, August 15-17, 1983

    NASA Astrophysics Data System (ADS)

    Fast, R. W.

    Applications of superconductivity are discussed, taking into account the thermal performance of the MFTF magnets, the design and testing of a large bore superconducting magnet test facility, the development of a 12-tesla multifilamentary Nb3Sn magnet, a superconducting magnet for solid NMR studies, advanced applications of superconductors, transition and recovery of a cryogenically stable superconductor, and finite-difference modeling of the cryostability of helium II cooled conductor packs. Other topics explored are related to resource availability, heat exchangers, heat transfer to He I, liquid nitrogen, heat transfer in He II, refrigeration for superconducting and cryopump systems, refrigeration of cryogenic systems, refrigeration and liquefaction, dilution and magnetic refrigeration, cryocoolers, refrigeration for space applications, cryogenic applications, cryogenic instrumentation and data acquisition, and properties of fluids. Attention is given to biomedical applications of cryogenics in China, long-term cryogen storage in space, and a passive orbital disconnect strut.

  16. Advances in Cryogenic Principles

    NASA Astrophysics Data System (ADS)

    Barron, R. F.

    During the past 50 years, the use of digital computers has significantly influenced the design and analysis of cryogenic systems. At the time when the first Cryogenic Engineering Conference was held, thermodynamic data were presented in graphical or tabular form (the "steam table" format), whereas thermodynamic data for cryogenic system design is computer generated today. The thermal analysis of cryogenic systems in the 1950s involved analytical solutions, graphical solutions, and relatively simple finite-difference approaches. These approaches have been supplanted by finite-element numerical programs which readily solve complicated thermal problems that could not be solved easily using the methods of the 1950s. In distillation column design, the use of the McCabe-Thiele graphical method for determination of the number of theoretical plates has been replaced by numerical methods that allow consideration of several different components in the feed and product streams.

  17. Cryogenic readout techniques for germanium detectors

    SciTech Connect

    Benato, G.; Cattadori, C.; Di Vacri, A.; Ferri, E.

    2015-07-01

    High Purity Germanium detectors are used in many applications, from nuclear and astro-particle physics, to homeland security or environment protection. Although quite standard configurations are often used, with cryostats, charge sensitive amplifiers and analog or digital acquisition systems all commercially available, it might be the case that a few specific applications, e.g. satellites, portable devices, cryogenic physics experiments, etc. also require the development of a few additional or complementary techniques. An interesting case is for sure GERDA, the Germanium Detector Array experiment, searching for neutrino-less double beta decay of {sup 76}Ge at the Gran Sasso National Laboratory of INFN - Italy. In GERDA the entire detector array, composed of semi-coaxial and BEGe naked crystals, is operated suspended inside a cryostat filled with liquid argon, that acts not only as cooling medium and but also as an active shield, thanks to its scintillation properties. These peculiar circumstances, together with the additional requirement of a very low radioactive background from all the materials adjacent to the detectors, clearly introduce significant constraints on the design of the Ge front-end readout electronics. All the Ge readout solutions developed within the framework of the GERDA collaboration, for both Phase I and Phase II, will be briefly reviewed, with their relative strength and weakness compared together and with respect to ideal Ge readout. Finally, the digital processing techniques developed by the GERDA collaboration for energy estimation of Ge detector signals will be recalled. (authors)

  18. Cryogenic Shutter Mechanism

    NASA Technical Reports Server (NTRS)

    Barney, Richard D.; Magner, Thomas J.

    1989-01-01

    Electromagnetic shutter mechanism operates at ambient and cryogenic temperatures to shield optical element, such as mirror, filter, polarizer, beam splitter, or detector, from external light and radiation in cryogenic Dewar equipped with window for optical evaluation. Shutter mechanism in Dewar container alternately shields and exposes optical element as paddle rotates between mechanical stops. Mounted on cold plate of liquid-helium reservoir. Paddle, shaft, and magnet constitutes assembly rotated by electromagnetic field on coil.

  19. Cryogenic Feedthrough Test Rig

    NASA Technical Reports Server (NTRS)

    Skaff, Antony

    2009-01-01

    The cryogenic feedthrough test rig (CFTR) allows testing of instrumentation feedthroughs at liquid oxygen and liquid hydrogen temperature and pressure extremes (dangerous process fluid) without actually exposing the feedthrough to a combustible or explosive process fluid. In addition, the helium used (inert gas), with cryogenic heat exchangers, exposes the feedthrough to that environment that allows definitive leak rates of feedthrough by typical industry-standard helium mass spectrometers.

  20. Vuilleumier Cycle Cryogenic Refrigeration

    DTIC Science & Technology

    1976-04-01

    WORDS (Continue on reverse side if necessary and identify by block number) Cryogenic Refrigerator Vuilleumier Cycle 20. ABSTRACT (Continue on reverse ...The energy added to the gas was stored in the regenerator packing, or matrix, by gas flow in the reverse direction during a previous part of the cycle ...AFFDL-TR-76-17 VUILLEUMIER CYCLE CRYOGENIC REFRIGERATION ENVIRONMENTAL CONTROL BRANCH 4 VEHICLE EQUIPMENT DIVISION APRIL 1976 TECHNICAL REPORT AFFDL

  1. Cryogenic Field Measurement of Pr2Fe14B Undulator and Performance Enhancement Options at the NSLS-II

    SciTech Connect

    Tanabe, T.; Chubar, O.; Harder, David A.; Lehecka, Michael; Rank, James; Rakowsky, George; Spataro, Charles

    2009-09-27

    Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr{sub 2}Fe{sub 14}B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd{sub 2}Fe{sub 14}B) magnets which exhibit spin reorientation at temperatures below 150K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the posibility for use in operating a cryo-permanent magnet undulator (CPMU) in the range of 40K to 60K where very efficient cryocoolers are available. Magnetic flux density profiles were measured at various temperature ranges from room temperature down to liquid helium (LHe) using the Vertical Testing Facility (VTF) at the National Snchrotron Light Source-II (NSLS-II). Temperature variations of phase error have been characterized. In addition, we examined the use of textured Dysprosium (Dy) poles to replace permendur poles to obtain further improvement in performance.

  2. First Results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Akerib, D. S.; Alvaro-Dean, J.; Armel-Funkhouser, M. S.; Attisha, M. J.; Baudis, L.; Bauer, D. A.; Beaty, J.; Brink, P. L.; Bunker, R.; Burke, S. P.; Cabrera, B.; Caldwell, D. O.; Callahan, D.; Castle, J. P.; Chang, C. L.; Choate, R.; Crisler, M. B.; Cushman, P.; Dixon, R.; Dragowsky, M. R.; Driscoll, D. D.; Duong, L.; Emes, J.; Ferril, R.; Filippini, J.; Gaitskell, R. J.; Haldeman, M.; Hale, D.; Holmgren, D.; Huber, M. E.; Johnson, B.; Johnson, W.; Kamat, S.; Kozlovsky, M.; Kula, L.; Kyre, S.; Lambin, B.; Lu, A.; Mahapatra, R.; Manalaysay, A. G.; Mandic, V.; May, J.; McDonald, R.; Merkel, B.; Meunier, P.; Mirabolfathi, N.; Morrison, S.; Nelson, H.; Nelson, R.; Novak, L.; Ogburn, R. W.; Orr, S.; Perera, T. A.; Perillo Isaac, M. C.; Ramberg, E.; Rau, W.; Reisetter, A.; Ross, R. R.; Saab, T.; Sadoulet, B.; Sander, J.; Savage, C.; Schmitt, R. L.; Schnee, R. W.; Seitz, D. N.; Serfass, B.; Smith, A.; Smith, G.; Spadafora, A. L.; Sundqvist, K.; Thompson, J.-P. F.; Tomada, A.; Wang, G.; Williams, J.; Yellin, S.; Young, B. A.

    2004-11-01

    We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6live days, providing 19.4kg d of Ge net exposure after cuts for recoil energies between 10 and 100keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4×10-43 cm2 at a WIMP mass of 60 GeV/c2.

  3. First results from the Cryogenic Dark Matter Search in the Soudan Underground Laboratory.

    PubMed

    Akerib, D S; Alvaro-Dean, J; Armel-Funkhouser, M S; Attisha, M J; Baudis, L; Bauer, D A; Beaty, J; Brink, P L; Bunker, R; Burke, S P; Cabrera, B; Caldwell, D O; Callahan, D; Castle, J P; Chang, C L; Choate, R; Crisler, M B; Cushman, P; Dixon, R; Dragowsky, M R; Driscoll, D D; Duong, L; Emes, J; Ferril, R; Filippini, J; Gaitskell, R J; Haldeman, M; Hale, D; Holmgren, D; Huber, M E; Johnson, B; Johnson, W; Kamat, S; Kozlovsky, M; Kula, L; Kyre, S; Lambin, B; Lu, A; Mahapatra, R; Manalaysay, A G; Mandic, V; May, J; McDonald, R; Merkel, B; Meunier, P; Mirabolfathi, N; Morrison, S; Nelson, H; Nelson, R; Novak, L; Ogburn, R W; Orr, S; Perera, T A; Perillo Isaac, M C; Ramberg, E; Rau, W; Reisetter, A; Ross, R R; Saab, T; Sadoulet, B; Sander, J; Savage, C; Schmitt, R L; Schnee, R W; Seitz, D N; Serfass, B; Smith, A; Smith, G; Spadafora, A L; Sundqvist, K; Thompson, J-P F; Tomada, A; Wang, G; Williams, J; Yellin, S; Young, B A

    2004-11-19

    We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2.

  4. NASA's Cryogenic Fluid Management Technology Project

    NASA Technical Reports Server (NTRS)

    Tramel, Terri L.; Motil, Susan M.

    2008-01-01

    The Cryogenic Fluid Management (CFM) Project's primary objective is to develop storage, transfer, and handling technologies for cryogens that will support the enabling of high performance cryogenic propulsion systems, lunar surface systems and economical ground operations. Such technologies can significantly reduce propellant launch mass and required on-orbit margins, reduce or even eliminate propellant tank fluid boil-off losses for long term missions, and simplify vehicle operations. This paper will present the status of the specific technologies that the CFM Project is developing. The two main areas of concentration are analysis models development and CFM hardware development. The project develops analysis tools and models based on thermodynamics, hydrodynamics, and existing flight/test data. These tools assist in the development of pressure/thermal control devices (such as the Thermodynamic Vent System (TVS), and Multi-layer insulation); with the ultimate goal being to develop a mature set of tools and models that can characterize the performance of the pressure/thermal control devices incorporated in the design of an entire CFM system with minimal cryogen loss. The project does hardware development and testing to verify our understanding of the physical principles involved, and to validate the performance of CFM components, subsystems and systems. This database provides information to anchor our analytical models. This paper describes some of the current activities of the NASA's Cryogenic Fluid Management Project.

  5. RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN

    SciTech Connect

    Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2010-05-23

    Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

  6. The aerodynamic design and performance of the NASA/GE E3 low pressure turbine

    NASA Technical Reports Server (NTRS)

    Cherry, D. G.; Dengler, R. P.

    1984-01-01

    The aerodynamic design and scaled rig test results of the low pressure turbine (LPT) component for the NASA/General Electric Energy Efficient Engine (E3) are presented. The low pressure turbine is a highly loaded five-stage design featuring high outer wall slope, controlled vortex aerodynamics, low stage flow coefficient, and reduced clearances. An assessment of its performance has been made based on a series of scaled air turbine tests which were divided into two phases: Block I (March through August, 1979) and Block II (June through September, 1981). Results from the Block II five-stage test, summarized in the paper, indicate that the E3 LPT will attain an efficiency level of 91.5 percent at the Mach 0.8/35,000 ft. max. climb altitude design point. This is relative to program goals of 91.1 percent for the E3 demonstrator engine and 91.7 percent for a fully developed flight propulsion system LPT.

  7. NASA/GE Energy Efficient Engine low pressure turbine scaled test vehicle performance report

    NASA Technical Reports Server (NTRS)

    Bridgeman, M. J.; Cherry, D. G.; Pedersen, J.

    1983-01-01

    The low pressure turbine for the NASA/General Electric Energy Efficient Engine is a highly loaded five-stage design featuring high outer wall slope, controlled vortex aerodynamics, low stage flow coefficient, and reduced clearances. An assessment of the performance of the LPT has been made based on a series of scaled air-turbine tests divided into two phases: Block 1 and Block 2. The transition duct and the first two stages of the turbine were evaluated during the Block 1 phase from March through August 1979. The full five-stage scale model, representing the final integrated core/low spool (ICLS) design and incorporating redesigns of stages 1 and 2 based on Block 1 data analysis, was tested as Block 2 in June through September 1981. Results from the scaled air-turbine tests, reviewed herein, indicate that the five-stage turbine designed for the ICLS application will attain an efficiency level of 91.5 percent at the Mach 0.8/10.67-km (35,000-ft), max-climb design point. This is relative to program goals of 91.1 percent for the ICLS and 91.7 percent for the flight propulsion system (FPS).

  8. Performance of a Cryogenic Multipath Herriott Cell Vacuum-Coupled to a Bruker IFS-125HR System

    NASA Astrophysics Data System (ADS)

    Mantz, Arlan; Sung, Keeyoon; Crawford, Timothy J.; Brown, Linda; Smith, Mary Ann H.

    2014-06-01

    Accurate modeling of atmospheric trace gases requires detailed knowledge of spectroscopic line parameters at temperatures and pressures relevant to the atmospheric layers where the spectroscopic signatures form. Pressure-broadened line shapes, frequency shifts, and their temperature dependences, are critical spectroscopic parameters that limit the accuracy of state-of-the-art atmospheric remote sensing. In order to provide temperature dependent parameters from controlled laboratory experiments, a 20.946 ± 0.001 m long path Herriott cell and associated transfer optics were designed and fabricated at Connecticut College to operate in the near infrared using a Bruker 125 HR Fourier transform spectrometer. The cell body and gold coated mirrors are fabricated with Oxygen-Free High Conductivity (OFHC) copper. Transfer optics are through-put matched for entrance apertures smaller than 2 mm. A closed-cycle Helium refrigerator cools the cell and cryopumps the surrounding vacuum box. This new system and its transfer optics are fully evacuated to ˜10 mTorr (similar to the pressure inside the interferometer). Over a period of several months, this system has maintained extremely good stability in recording spectra at gas sample temperatures between 75 and 250 K. The absorption path length and cell temperatures are validated using CO spectra. The characterization of the Herriott cell is described along with its performance and future applications. We thank Drs. V. Malathy Devi and D. Chris Benner at The College of William and Mary for helpful discussion. Research described in this paper was performed at Connecticut College, the Jet Propulsion Laboratory, California Institute of Technology, and NASA Langley Research Center, under contracts and cooperative agreements with the National Aeronautics and Space Administration.

  9. Measurements of the performance of a beam condition monitor prototype in a 5 GeV electron beam

    NASA Astrophysics Data System (ADS)

    Hempel, M.; Afanaciev, K.; Burtowy, P.; Dabrowski, A.; Henschel, H.; Idzik, M.; Karacheban, O.; Lange, W.; Leonard, J.; Levy, I.; Lohmann, W.; Pollak, B.; Przyborowski, D.; Ryjov, V.; Schuwalow, S.; Stickland, D.; Walsh, R.; Zagozdzinska, A.

    2016-08-01

    The Fast Beam Conditions Monitor, BCM1F, in the Compact Muon Solenoid, CMS, experiment was operated since 2008 and delivered invaluable information on the machine induced background in the inner part of the CMS detector supporting a safe operation of the inner tracker and high quality data. Due to the shortening of the time between two bunch crossings from 50 ns to 25 ns and higher expected luminosity at the Large Hadron Collider, LHC, in 2015, BCM1F needed an upgrade to higher bandwidth. In addition, BCM1F is used as an on-line luminometer operated independently of CMS. To match these requirements, the number of single crystal diamond sensors was enhanced from 8 to 24. Each sensor is subdivided into two pads, leading to 48 readout channels. Dedicated fast front-end ASICs were developed in 130 nm technology, and the back-end electronics is completely upgraded. An assembled prototype BCM1F detector comprising sensors, a fast front-end ASIC and optical analog readout was studied in a 5 GeV electron beam at the DESY-II accelerator. Results on the performance are given.

  10. Brush Seals for Cryogenic Applications: Performance, Stage Effects, and Preliminary Wear Results in LN2 and LH2

    NASA Technical Reports Server (NTRS)

    Proctor, Margaret P.; Walker, James F.; Perkins, H. Douglas; Hoopes, Joan F.; Williamson, G. Scott

    1996-01-01

    Brush seals are compliant contacting seals and have significantly lower leakage than labyrinth seals in gas turbine applications. Their long life and low leakage make them candidates for use in rocket engine turbopumps. Brush seals, 50.8 mm (2 in.) in diameter with a nominal 127-micron (0.005-in.) radial interference, were tested in liquid nitrogen (LN2) and liquid hydrogen (LH2) at shaft speeds up to 35,000 and 65,000 rpm, respectively, and at pressure drops up to 1.21 MPa (175 psid) per brush. A labyrinth seal was also tested in liquid nitrogen to provide a baseline. The LN2 leakage rate of a single brush seal with an initial radial shaft interference of 127 micron (0.005 in.) measured one-half to one-third the leakage rate of a 12-tooth labyrinth seal with a radial clearance of 127 micron (0.005 in.). Two brushes spaced 7.21 micron (0.248 in.) apart leaked about one-half as much as a single brush, and two brushes tightly packed together leaked about three-fourths as much as a single brush. The maximum measured groove depth on the Inconel 718 rotor with a surface finish of 0.81 micron (32 microinch) was 25 micron (0.0010 in.) after 4.3 hr of shaft rotation in liquid nitrogen. The Haynes-25 bristles wore approximately 25 to 76 micron (0.001 to 0.003 in.) under the same conditions. Wear results in liquid hydrogen were significantly different. In liquid hydrogen the rotor did not wear, but the bristle material transferred onto the rotor and the initial 127 micron (0.005 in.) radial interference was consumed. Relatively high leakage rates were measured in liquid hydrogen. More testing is required to verify the leakage performance, to validate and calibrate analysis techniques, and to determine the wear mechanisms. Performance, staging effects, and preliminary wear results are presented.

  11. Commissioning the cryogenic system of the first LHC sector

    SciTech Connect

    Millet, F.; Claudet, S.; Ferlin, G.; Perin, A.; Riddone, G.; Serio, L.; Soubiran, M.; Tavian, L.; Ronayette, L.; Rabehl, R.; /Fermilab

    2007-12-01

    The LHC machine, composed of eight sectors with superconducting magnets and accelerating cavities, requires a complex cryogenic system providing high cooling capacities (18 kW equivalent at 4.5 K and 2.4 W at 1.8 K per sector produced in large cold boxes and distributed via 3.3-km cryogenic transfer lines). After individual reception tests of the cryogenic subsystems (cryogen storages, refrigerators, cryogenic transfer lines and distribution boxes) performed since 2000, the commissioning of the cryogenic system of the first LHC sector has been under way since November 2006. After a brief introduction to the LHC cryogenic system and its specificities, the commissioning is reported detailing the preparation phase (pressure and leak tests, circuit conditioning and flushing), the cool-down sequences including the handling of cryogenic fluids, the magnet powering phase and finally the warm-up. Preliminary conclusions on the commissioning of the first LHC sector will be drawn with the review of the critical points already solved or still pending. The last part of the paper reports on the first operational experience of the LHC cryogenic system in the perspective of the commissioning of the remaining LHC sectors and the beam injection test.

  12. High-precision cryogenic wheel mechanisms of the JWST/MIRI instrument: performance of the flight models

    NASA Astrophysics Data System (ADS)

    Krause, O.; Müller, F.; Birkmann, S.; Böhm, A.; Ebert, M.; Grözinger, U.; Henning, Th.; Hofferbert, R.; Huber, A.; Lemke, D.; Rohloff, R.-R.; Scheithauer, S.; Gross, T.; Fischer, T.; Luichtel, G.; Merkle, H.; Übele, M.; Wieland, H.-U.; Amiaux, J.; Jager, R.; Glauser, A.; Parr-Burman, P.; Sykes, J.

    2010-07-01

    The Mid Infrared Instrument (MIRI) aboard JWST is equipped with one filter wheel and two dichroic-grating wheel mechanisms to reconfigure the instrument between observing modes such as broad/narrow-band imaging, coronagraphy and low/medium resolution spectroscopy. Key requirements for the three mechanisms with up to 18 optical elements on the wheel include: (1) reliable operation at T = 7 K, (2) high positional accuracy of 4 arcsec, (3) low power dissipation, (4) high vibration capability, (5) functionality at 7 K < T < 300 K and (6) long lifetime (5-10 years). To meet these requirements a space-proven wheel concept consisting of a central MoS2-lubricated integrated ball bearing, a central torque motor for actuation, a ratchet system with monolithic CuBe flexural pivots for precise and powerless positioning and a magnetoresistive position sensor has been implemented. We report here the final performance and lessons-learnt from the successful acceptance test program of the MIRI wheel mechanism flight models. The mechanisms have been meanwhile integrated into the flight model of the MIRI instrument, ready for launch in 2014 by an Ariane 5 rocket.

  13. Performance enhancement in uniaxially tensile stressed GeSn n-channel fin tunneling field-effect transistor: Impact of stress direction

    NASA Astrophysics Data System (ADS)

    Wang, Hongjuan; Han, Genquan; Jiang, Xiangwei; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2017-04-01

    In this work, the boosting effect on the performance of GeSn n-channel fin tunneling FET (nFinTFET) enabled by uniaxial tensile stress is investigated theoretically. As the fin rotates within the (001) plane, the uniaxial tensile stress is always along its direction. The electrical characteristics of tensile-stressed GeSn nFinTFETs with point and line tunneling modes are computed utilizing the technology computer aided design (TCAD) simulator in which the dynamic nonlocal band-to-band tunneling (BTBT) algorithm is employed. In comparison with the relaxed devices, tensile-stressed GeSn nFinTFETs achieve a substantial enhancement in band-to-band tunneling generation rate (G BTBT) and on-state current I ON owing to the reduced bandgap E G induced by the tensile stress. Performance improvement of GeSn nFinTFETs induced by tensile stress demonstrates a strong dependence on channel direction and tunneling modes. Under the same magnitude of stress, line-nFinTFETs obtain a more pronounced I ON enhancement over the transistors with point tunneling mode.

  14. Spacecraft cryogenic gas storage systems

    NASA Technical Reports Server (NTRS)

    Rysavy, G.

    1971-01-01

    Cryogenic gas storage systems were developed for the liquid storage of oxygen, hydrogen, nitrogen, and helium. Cryogenic storage is attractive because of the high liquid density and low storage pressure of cryogens. This situation results in smaller container sizes, reduced container-strength levels, and lower tankage weights. The Gemini and Apollo spacecraft used cryogenic gas storage systems as standard spacecraft equipment. In addition to the Gemini and Apollo cryogenic gas storage systems, other systems were developed and tested in the course of advancing the state of the art. All of the cryogenic storage systems used, developed, and tested to date for manned-spacecraft applications are described.

  15. The integrated cryogenic system for the atmospheric vertical interferometric detector on FY-4 satellite

    NASA Astrophysics Data System (ADS)

    Wu, Yinong; Liu, EnGuang; Jiang, Zhenhua; Yang, Baoyu; Mu, Yongbin

    2016-05-01

    The cryogenic system for the atmospheric vertical interferometric detector on FY-4 satellite includes a Stirling cryocooler, a radiant cooler, a cryogenic heat pipe and some flexible thermal links as well. These cryogenic elements were integrated together in order to decrease the background radiation and maximize the sensitivity with high efficiency and high reliability. This paper summarizes the cryogenic integration design, technical challenges, and the results of thermal and performance testing.

  16. Cryogenic Permanent Magnet Undulators

    SciTech Connect

    Chavanne, J.; Lebec, G.; Penel, C.; Revol, F.; Kitegi, C.

    2010-06-23

    For an in-vacuum undulator operated at small gaps the permanent magnet material needs to be highly resistant to possible electron beam exposure. At room temperature, one generally uses Sm{sub 2}Co{sub 17} or high coercivity NdFeB magnets at the expense of a limited field performance. In a cryogenic permanent magnet undulator (CPMU), at a temperature of around 150 K, any NdFeB grade reveals a coercivity large enough to be radiation resistant. In particular, very high remanence NdFeB material can be used to build undulators with enhanced field and X-ray brilliance at high photon energy provided that the pre-baking of the undulator above 100 deg. C can be eliminated. The ESRF has developed a full scale 2 m long CPMU with a period of 18 mm. This prototype has been in operation on the ID6 test beamline since January 2008. A significant effort was put into the characterization of NdFeB material at low temperature, the development of dedicated magnetic measurement systems and cooling methods. The measured heat budget with beam is found to be larger than expected without compromising the smooth operation of the device. Leading on from this first experience, new CPMUs are currently being considered for the upgrade of the ESRF.

  17. Active Costorage of Cryogenic Propellants for Exploration

    NASA Technical Reports Server (NTRS)

    Canavan, Edgar R.; Boyle, Rob; Mustafi, Shuvo

    2008-01-01

    Long-term storage of cryogenic propellants is a critical requirement for NASA's effort to return to the moon. Liquid hydrogen and liquid oxygen provide the highest specific impulse of any practical chemical propulsion system, and thus provides the greatest payload mass per unit of launch mass. Future manned missions will require vehicles with the flexibility to remain in orbit for months, necessitating long-term storage of these cryogenic liquids. For decades cryogenic scientific satellites have used cryogens to cool instruments. In many cases, the lifetime of the primary cryogen tank has been extended by intercepting much of the heat incident on the tank at an intermediate-temperature shield cooled either by a second cryogen tank or a mechanical cryocooler. For an LH2/LO2 propellant system, a combination of these ideas can be used, in which the shield around the LO2 tank is attached to, and at the same temperature as, the LO2 tank, but is actively cooled so as to remove all heat impinging on the tank and shield. This configuration eliminates liquid oxygen boil-off and cuts the liquid hydrogen boil-off to a small fraction of the unshielded rate. This paper studies the concept of active costorage as a means of long-term cryogenic propellant storage. The paper describes the design impact of an active costorage system for the Crew Exploration Vehicle (CEV). This paper also compares the spacecraft level impact of the active costorage concept with a passive storage option in relation to two different scales of spacecraft that will be used for the lunar exploration effort, the CEV and the Earth Departure Stage (EDS). Spacecraft level studies are performed to investigate the impact of scaling of the costorage technologies for the different components of the Lunar Architecture and for different mission durations.

  18. The role of nanoscale defect features in enhancing the thermoelectric performance of p-type nanostructured SiGe alloys.

    PubMed

    Bathula, Sivaiah; Jayasimhadri, M; Gahtori, Bhasker; Singh, Niraj Kumar; Tyagi, Kriti; Srivastava, A K; Dhar, Ajay

    2015-08-07

    Despite SiGe being one of the most widely studied thermoelectric materials owing to its application in radioisotope thermoelectric generators (RTG), the thermoelectric figure-of merit (ZT) of p-type SiGe is still quite low, resulting in poor device efficiencies. In the present study, we report a substantial enhancement in ZT∼ 1.2 at 900 °C for p-type nanostructured Si80Ge20 alloys by creating several types of defect features within the Si80Ge20 nanostructured matrix in a spectrum of nano to meso-scale dimensions during its nanostructuring, by employing mechanical alloying followed by spark plasma sintering. This enhancement in ZT, which is ∼25% over the existing state-of-the-art value for a p-type nanostructured Si80Ge20 alloy, is primarily due to its ultralow thermal conductivity of ∼2.04 W m(-1) K(-1) at 900 °C, resulting from the scattering of low-to-high wavelength heat-carrying phonons by different types of defect features in a range of nano to meso-scale dimensions in the Si80Ge20 nanostructured matrix. These include point defects, dislocations, isolated amorphous regions, nano-scale grain boundaries and more importantly, the nano to meso-scale residual porosity distributed throughout the Si80Ge20 matrix. These nanoscale multi-dimensional defect features have been characterized by employing scanning and transmission electron microscopy and correlated with the electrical and thermal transport properties, based on which the enhancement of ZT has been discussed.

  19. Cryogenic Insulation Bondline Studies for Reusable Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Johnson, T. F.; Weiser, E. S.; Duong, P. G.

    2003-01-01

    Cryogenic insulations bonded to metallic substrates were characterized under simulated mission conditions representative for a reusable launch vehicle. The combined thermal and mechanical test consisted of 50 to a 100 cycles. These combined thermal and mechanical cycles simulated flight missions with temperatures ranging from -423 F to 450 F and a maximum mechanical tension load ranging from 20,000 lbs. to 97,650 lbs. The combined thermal and mechanical (uniaxial tension) test apparatus (1 ft. by 2 ft. Test Apparatus) developed at the NASA Langley Research Center, was used to perform cyclic tests on cryogenic insulations bonded to tank wall substrates. No visual delamination or degradation was observed in the cryogenic insulation-to-metallic substrate bondline or butt joints between cryogenic insulation panels. In addition, after cyclic testing was performed, residual property results from tension-pull and closed-cell content tests of the cryogenic insulations indicated a decrease in the bondline strength and closed-cell content.

  20. TPC magnet cryogenic system

    SciTech Connect

    Green, M.A.; Burns, W.A.; Taylor, J.D.; Van Slyke, H.W.

    1980-03-01

    The Time Projection Chamber (TPC) magnet at LBL and its compensation solenoids are adiabatically stable superconducting solenoid magnets. The cryogenic system developed for the TPC magnet is discussed. This system uses forced two-phase tubular cooling with the two cryogens in the system. The liquid helium and liquid nitrogen are delivered through the cooled load by forced tubular flow. The only reservoirs of liquid cryogen exist in the control dewar (for liquid helium) and the conditioner dewar (for liquid nitrogen). The operation o these systems during virtually all phases of system operation are described. Photographs and diagrams of various system components are shown, and cryogenic system data are presented in the following sections: (1) heat leaks into the TPC coil package and the compensation solenoids; (2) heat leaks to various components of the TPC magnet cryogenics system besides the magnets and control dewar; (3) the control dewar and its relationship to the rest of the system; (4) the conditioner system and its role in cooling down the TPC magnet; (5) gas-cooled electrical leads and charging losses; and (6) a summation of the liquid helium and liquid nitrogen requirements for the TPC superconducting magnet system.

  1. Cryogenic optical systems and instruments V; Proceedings of the Meeting, San Diego, CA, July 23, 24, 1992

    NASA Technical Reports Server (NTRS)

    Melugin, Ramsey K. (Editor)

    1993-01-01

    Topics discussed in this volume include cryogenic system design and optical technology; cryogenic instruments; cryogenic/IR mechanisms, testing, and performance; and space cryogenic dewars and coolers. Papers included are on the SIRTF cryooptics technology plan, the development of the SPIRIT III sensor, the design of a rapidly cooled cryogenic mirror, the cryogenic Michelson interferometer on the Space Shuttle, a reflective optical system for a hemispherical field radiometer, and infrared filters for cryogenic radiometers. Attention is also given to the development of a variable-profile scan mirror mechanism, a direct-drive digitally commutated filter wheel positioning system for cryogenic optical applications, a high-performance chopping secondary mirror for infrared astronomy, recent developments in compressor-based Joule-Thomson cooling, a radiative cryogenic cooler for the pressure modulator IR radiometer, and SIRTF thermal design modifications to increase lifetime.

  2. High intensity low temperature (HILT) performance of space concentrator GaInP/GaInAs/Ge MJ SCs

    SciTech Connect

    Shvarts, Maxim Z. Kalyuzhnyy, Nikolay A.; Mintairov, Sergey A.; Soluyanov, Andrei A.; Timoshina, Nailya Kh.; Gudovskikh, Alexander S.; Luque, Antonio

    2014-09-26

    In the work, the results of an investigation of GaInP/GaInAs/Ge MJ SCs intended for converting concentrated solar radiation, when operating at low temperatures (down to −190 °C) are presented. A kink of the cell I-V characteristic has been observed in the region close to V{sub oc} starting from −20°C at operation under concentrated sunlight. The causes for its occurrence have been analyzed and the reasons for formation of a built-in potential barrier for majority charge carriers at the n-GaInP/n-Ge isotype hetero-interface are discussed. The effect of charge carrier transport in n-GaInP/n-pGe heterostructures on MJ SC output characteristics at low temperatures has been studied including EL technique.

  3. Enhanced thermoelectric performance of In-substituted GeSb{sub 6}Te{sub 10} with homologous structure

    SciTech Connect

    Kosuga, Atsuko Matsuzawa, Mie; Fujii, Yousuke; Nakai, Kazuki; Funahashi, Ryoji; Tachizawa, Takuya; Kubota, Yoshiki; Kifune, Kouichi

    2014-08-01

    We studied the crystal structure and thermoelectric properties of polycrystalline GeIn{sub x}Sb{sub 6−x}Te{sub 10} (x = 0, 0.18, 0.3, and 0.6). Rietveld and Le Bail analyses showed that all compositions crystallized in trigonal structures with a 51-layer period. Substituting In decreased both the lattice and electronic thermal conductivity, as well as markedly increased the Seebeck coefficient. We ascribed this increase to increases in the effective mass of the carriers, likely caused by the formation of additional energy states near the Fermi level. In GeIn{sub 0.6}Sb{sub 5.4}Te{sub 10}, we found a maximum ZT of 0.75 at 710 K, 1.9 times higher than that of GeSb{sub 6}Te{sub 10}.

  4. Cryogenic wind tunnels. II

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1987-01-01

    The application of the cryogenic concept to various types of tunnels including Ludwieg tube tunnel, Evans clean tunnel, blowdown, induced-flow, and continuous-flow fan-driven tunnels is discussed. Benefits related to construction and operating costs are covered, along with benefits related to new testing capabilities. It is noted that cooling the test gas to very low temperatures increases Reynolds number by more than a factor of seven. From the energy standpoint, ambient-temperature fan-driven closed-return tunnels are considered to be the most efficient type of tunnel, while a large reduction in the required tunnel stagnation pressure can be achieved through cryogenic operation. Operating envelopes for three modes of operation for a cryogenic transonic pressure tunnel with a 2.5 by 2.5 test section are outlined. A computer program for calculating flow parameters and power requirements for wind tunnels with operating temperatures from saturation to above ambient is highlighted.

  5. Cryogenic propulsion for lunar and Mars missions

    NASA Technical Reports Server (NTRS)

    Redd, Larry

    1988-01-01

    Future missions to the moon and Mars have been investigated with regard to propulsion system selection. The results of this analysis show that near state-of-the-art LO2/LH2 propulsion technology provides a feasible means of performing lunar missions and trans-Mars injections. In other words, existing cryogenic space engines with certain modifications and product improvements would be suitable for these missions. In addition, present day cryogenic system tankage and structural weights appear to scale reasonably when sizing for large payload and high energy missions such as sending men to Mars.

  6. Cryogenic hydrogen-induced air liquefaction technologies

    NASA Technical Reports Server (NTRS)

    Escher, William J. D.

    1990-01-01

    Extensively utilizing a special advanced airbreathing propulsion archives database, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen-induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented. The resulting assessment report is summarized. Technical findings are presented relating the status of air liquefaction technology, both as a singular technical area, and also that of a cluster of collateral technical areas including: compact lightweight cryogenic heat exchangers; heat exchanger atmospheric constituents fouling alleviation; para/ortho hydrogen shift conversion catalysts; hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; hydrogen recycling using slush hydrogen as heat sink; liquid hydrogen/liquid air rocket-type combustion devices; air collection and enrichment systems (ACES); and technically related engine concepts.

  7. Process optimizations to recessed e-SiGe source/drain for performance enhancement in 22 nm all-last high-k/metal-gate pMOSFETs

    NASA Astrophysics Data System (ADS)

    Qin, Changliang; Wang, Guilei; Hong, Peizhen; Liu, Jinbiao; Yin, Huaxiang; Yin, Haizhou; Ma, Xiaolong; Cui, Hushan; Lu, Yihong; Meng, Lingkuan; Xiang, Jinjuan; Zhong, Huicai; Zhu, Huilong; Xu, Qiuxia; Li, Junfeng; Yan, Jian; Zhao, Chao; Radamson, Henry H.

    2016-09-01

    In this paper, the technology of recessed embedded SiGe (e-SiGe) source/drain (S/D) module is optimized for the performance enhancement in 22 nm all-last high-k/metal-gate (HK/MG) pMOSFETs. Different Si recess-etch techniques were applied in S/D regions to increase the strain in the channel and subsequently, improve the performance of transistors. A new recess-etch method consists of a two-step etch method is proposed. This process is an initial anisotropic etch for the formation of shallow trench followed by a final isotropic etch. By introducing the definition of the upper edge distance (D) between the recessed S/D region and the channel region, the process advantage of the new approach is clearly presented. It decreases the value of D than those by conventional one-step isotropic or anisotropic etch of Si. Therefore, the series resistance is reduced and the channel strain is increased, which confirmed by the simulation results. The physical reason of D reducing is analyzed in brief. Applying this recess design, the implant conditions for S/D extension (SDE) are also optimized by using a two-step implantation of BF2 in SiGe layers. The overlap space between doping junction and channel region has great effect on the device's performance. The designed implantation profile decreases the overlap space while keeps a shallow junction depth for a controllable short channel effect. The channel resistance as well as the transfer ID-VG curves varying with different process conditions are demonstrated. It shows the drive current of the device with the optimized SDE implant condition and Si recess-etch process is obviously improved. The change trend of on-off current distributions extracted from a series of devices confirmed the conclusions. This study provides a useful guideline for developing high performance strained PMOS SiGe technology.

  8. Cryogenic Model Materials

    NASA Technical Reports Server (NTRS)

    Kimmel, W. M.; Kuhn, N. S.; Berry, R. F.; Newman, J. A.

    2001-01-01

    An overview and status of current activities seeking alternatives to 200 grade 18Ni Steel CVM alloy for cryogenic wind tunnel models is presented. Specific improvements in material selection have been researched including availability, strength, fracture toughness and potential for use in transonic wind tunnel testing. Potential benefits from utilizing damage tolerant life-prediction methods, recently developed fatigue crack growth codes and upgraded NDE methods are also investigated. Two candidate alloys are identified and accepted for cryogenic/transonic wind tunnel models and hardware.

  9. Cryogenic foil bearing turbopumps

    NASA Technical Reports Server (NTRS)

    Gu, Alston L.

    1993-01-01

    Cryogenic foil bearing turbopumps offer high reliability and low cost. The fundamental cryogenic foil bearing technology has been validated in both liquid hydrogen and liquid oxygen. High load capacity, excellent rotor dynamics, and negligible bearing wear after over 100 starts and stops, and over many hours of testing, were observed in both fluids. An experimental liquid hydrogen foil bearing turbopump was also successfully demonstrated. The results indicate excellent stability, high reliability, wide throttle-ability, low bearing cooling flow, and two-phase bearing operability. A liquid oxygen foil bearing turbopump has been built and is being tested at NASA MSFC.

  10. Cryogenic Hybrid Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  11. Cryogenic Propellant Densification Study

    NASA Technical Reports Server (NTRS)

    Ewart, R. O.; Dergance, R. H.

    1978-01-01

    Ground and vehicle system requirements are evaluated for the use of densified cryogenic propellants in advanced space transportation systems. Propellants studied were slush and triple point liquid hydrogen, triple point liquid oxygen, and slush and triple point liquid methane. Areas of study included propellant production, storage, transfer, vehicle loading and system requirements definition. A savings of approximately 8.2 x 100,000 Kg can be achieved in single stage to orbit gross liftoff weight for a payload of 29,484 Kg by utilizing densified cryogens in place of normal boiling point propellants.

  12. Simulations of Cavitating Cryogenic Inducers

    NASA Technical Reports Server (NTRS)

    Dorney, Dan (Technical Monitor); Hosangadi, Ashvin; Ahuja, Vineet; Ungewitter, Ronald J.

    2004-01-01

    Simulations of cavitating turbopump inducers at their design flow rate are presented. Results over a broad range of Nss, numbers extending from single-phase flow conditions through the critical head break down point are discussed. The flow characteristics and performance of a subscale geometry designed for water testing are compared with the fullscale configuration that employs LOX. In particular, thermal depression effects arising from cavitation in cryogenic fluids are identified and their impact on the suction performance of the inducer quantified. The simulations have been performed using the CRUNCH CFD[R] code that has a generalized multi-element unstructured framework suitable for turbomachinery applications. An advanced multi-phase formulation for cryogenic fluids that models temperature depression and real fluid property variations is employed. The formulation has been extensively validated for both liquid nitrogen and liquid hydrogen by simulating the experiments of Hord on hydrofoils; excellent estimates of the leading edge temperature and pressure depression were obtained while the comparisons in the cavity closure region were reasonable.

  13. Effective passivation and high-performance metal-oxide-semiconductor devices using ultra-high-vacuum deposited high- κ dielectrics on Ge without interfacial layers

    NASA Astrophysics Data System (ADS)

    Chu, L. K.; Chu, R. L.; Lin, T. D.; Lee, W. C.; Lin, C. A.; Huang, M. L.; Lee, Y. J.; Kwo, J.; Hong, M.

    2010-09-01

    Without using any interfacial passivation layers, high- κ dielectric Y 2O 3, HfO 2, and Ga 2O 3(Gd 2O 3) [GGO], by electron beam evaporation in ultra-high-vacuum (UHV), have been directly deposited on Ge substrate. Comprehensive investigations have been carried out to study the oxide/Ge interfaces chemically, structurally, and electronically: hetero-structures of all the studied oxides on Ge are highly thermally stable with annealing to 500 °C, and their interfaces remain atomically sharp. The electrical analyses have been conducted on metal-oxide-semiconductor (MOS) devices, i.e. MOS capacitors (MOSCAPs) and MOS field-effect-transistors (MOSFETs). Dielectrics constants of the Y 2O 3, HfO 2, and GGO have been extracted to be ˜17, 20, and 13-15, respectively, indicating no interfacial layer formation with 500 °C annealing. A low interfacial density of states ( Dits), as low as 3 × 10 11 cm -2 eV -1, has been achieved for GGO/Ge near mid-gap along with a high Fermi-level movement efficiency as high as 80%. The GGO/Ge pMOSFETs with TiN as the metal gate have yielded very high-performances, in terms of 496 μA/μm, 178 μS/μm, and 389 cm 2/V s in saturation drain current density, maximum transconductance, and effective hole mobility, respectively. The gate width and gate length of the MOSFET are 10 μm and 1 μm.

  14. Commissioning results of the U14 cryogenic undulator at SLS

    NASA Astrophysics Data System (ADS)

    Calvi, M.; Schmidt, Th; Anghel, A.; Cervellino, A.; Leake, S. J.; Willmott, P. R.; Tanaka, T.

    2013-03-01

    After 10 years of operation the wiggler-source Materials Science beamline at the Swiss Light Source was the first beamline to undergo a significant upgrade. The replacement of the W61 wiggler by the cryogenic undulator U14 makes the SLS the first wiggler free third generation light source. With the help of the cryogenic technology [1], the period length could be reduced from 19 mm to 14 mm. With a minimum gap of 3.8 mm and the x-ray energy range could be extended to nearly 40 keV. The undulator has been built in cooperation with SPring-8 and Hitachi. PSI designed the liquid-nitrogen-based cryogenic system and made the magnetic measurements under cryogenic conditions before installation. To be cost efficient, the undulator shares the cryogenic refrigeration system with the monochromator. Operational aspects like stability or temporal response to gap changes will be discussed as well as the spectral performance.

  15. Physical understanding of cryogenic implant benefits for electrical junction stability

    SciTech Connect

    Adeni Khaja, Fareen; Colombeau, Benjamin; Thanigaivelan, Thirumal; Ramappa, Deepak; Henry, Todd

    2012-03-12

    We investigate the effect of cryogenic temperature implants on electrical junction stability for ultra shallow junction applications for sub-32 nm technology nodes and beyond. A comprehensive study was conducted to gain physical understanding of the impact of cryogenic temperature implants on dopant-defect interactions. Carborane (C{sub 2}B{sub 10}H{sub 12}) molecule, a potential alternative to monomer boron was implanted in carbon preamorphized silicon substrates at cryogenic implant temperatures. Results indicate implants at cryogenic temperatures increase dopant activation with reduced diffusion, resulting in lower sheet resistance for a lower junction depth. Further, this study emphasizes the benefits of co-implants performed at cryogenic temperatures as alternative to traditional preamorphizing implants.

  16. Cryogenic Laser Calorimetry for Impurity Analysis

    NASA Technical Reports Server (NTRS)

    Swimm, R. T.

    1985-01-01

    The results of a one-year effort to determine the applicability of laser-calorimetric spectroscopy to the study of deep-level impurities in silicon are presented. Critical considerations for impurity analysis by laser-calorimetric spectroscopy are discussed, the design and performance of a cryogenic laser calorimeter is described, and measurements of background absorption in high-purity silicon are presented.

  17. Long-Term Cryogenic Propellant Storage for the TOPS Mission

    NASA Technical Reports Server (NTRS)

    Mustafi, Shuvo; Francis, John; Li, Xiaoyi; Purves, Lloyd; DeLee, Hudson; Riall, Sara; McGuinness, Dan; Willis, Dewey; Nixon, Conor; Devine Matt; Hedayat, Ali

    2015-01-01

    Cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LOX) can dramatically enhance NASAs ability to explore the solar system because of their superior specific impulse (Isp) capability. Although these cryogenic propellants can be challenging to manage and store, they allow significant mass advantages over traditional hypergolic propulsion systems and are therefore technically enabling for many planetary science missions. New cryogenic storage techniques such as subcooling and the use of advanced insulation and low thermal conductivity support structures will allow for the long term storage and use of cryogenic propellants for solar system exploration and hence allow NASA to deliver more payloads to targets of interest, launch on smaller and less expensive launch vehicles, or both. Employing cryogenic propellants will allow NASA to perform missions to planetary destinations that would not be possible with the use of traditional hypergolic propellants. These new cryogenic storage technologies were implemented in a design study for the Titan Orbiter Polar Surveyor (TOPS) mission, with LH2 and LOX as propellants, and the resulting spacecraft design was able to achieve a 43 launch mass reduction over a TOPS mission, that utilized a conventional hypergolic propulsion system with mono-methyl hydrazine (MMH) and nitrogen tetroxide (NTO) propellants. This paper describes the cryogenic propellant storage design for the TOPS mission and demonstrates how these cryogenic propellants are stored passively for a decade-long Titan mission.

  18. High Power Cryogenic Targets

    SciTech Connect

    Gregory Smith

    2011-08-01

    The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

  19. Valve for cryogenic service

    DOEpatents

    Worwetz, H.A.

    1975-09-02

    This patent relates to a valve for use with a liquefied gas at cryogenic temperatures in which a pair of joined knife edges are bellows controlled to contact an indium alloy seat in an annular slot when flow is to be stopped. The sealing alloy may be renewed by heating in situ. (auth)

  20. Cryogenic structural support

    DOEpatents

    Niemann, Ralph C.; Mataya, Karl F.; Gonczy, John D.

    1982-01-01

    A tensile support member is provided for use in a cryogenic environment. The member is in the form of a link formed of an epoxy glass laminate with at least one ply of the laminate having its fibers aligned circumferentially about the link.

  1. Robust Multilayer Insulation for Cryogenic Systems

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Scholtens, B. F.; Augustynowicz, S. D.

    2007-01-01

    New requirements for thermal insulation include robust Multilayer insulation (MU) systems that work for a range of environments from high vacuum to no vacuum. Improved MLI systems must be simple to install and maintain while meeting the life-cycle cost and thermal performance objectives. Performance of actual MLI systems has been previously shown to be much worse than ideal MLI. Spacecraft that must contain cryogens for both lunar service (high vacuum) and ground launch operations (no vacuum) are planned. Future cryogenic spacecraft for the soft vacuum environment of Mars are also envisioned. Industry products using robust MLI can benefit from improved cost-efficiency and system safety. Novel materials have been developed to operate as excellent thermal insulators at vacuum levels that are much less stringent than the absolute high vacuum requirement of current MLI systems. One such robust system, Layered Composite Insulation (LCI), has been developed by the Cryogenics Test Laboratory at NASA Kennedy Space Center. The experimental testing and development of LCI is the focus of this paper. LCI thermal performance under cryogenic conditions is shown to be six times better than MLI at soft vacuum and similar to MLI at high vacuum. The experimental apparent thermal conductivity (k-value) and heat flux data for LCI systems are compared with other MLI systems.

  2. Aerodynamic performance and pressure distributions for a NASA SC(2)-0714 airfoil tested in the Langley 0.3-meter transonic cryogenic tunnel

    NASA Technical Reports Server (NTRS)

    Jenkins, Renaldo V.; Hill, Acquilla S.; Ray, Edward J.

    1988-01-01

    This report presents in graphic and tabular forms the aerodynamic coefficient and surface pressure distribution data for a NASA SC(2)-0714 airfoil tested in the Langley 0.3-Meter Transonic Cryogenic Tunnel. The test was another in a series of tests involved in the joint NASA/U.S. Industry Advanced Technology Airfoil Tests program. This 14% thick supercritical airfoil was tested at Mach numbers from 0.6 to 0.76 and angles of attack from -2.0 to 6.0 degrees. The test Reynolds numbers were 4 million, 6 million, 10 million, 15 million, 30 million, 40 million, and 45 million.

  3. Cryogenic Fluid Management Technology for Moon and Mars Missions

    NASA Technical Reports Server (NTRS)

    Doherty, Michael P.; Gaby, Joseph D.; Salerno, Louis J.; Sutherlin, Steven G.

    2010-01-01

    In support of the U.S. Space Exploration Policy, focused cryogenic fluid management technology efforts are underway within the National Aeronautics and Space Administration. Under the auspices of the Exploration Technology Development Program, cryogenic fluid management technology efforts are being conducted by the Cryogenic Fluid Management Project. Cryogenic Fluid Management Project objectives are to develop storage, transfer, and handling technologies for cryogens to support high performance demands of lunar, and ultimately, Mars missions in the application areas of propulsion, surface systems, and Earth-based ground operations. The targeted use of cryogens and cryogenic technologies for these application areas is anticipated to significantly reduce propellant launch mass and required on-orbit margins, to reduce and even eliminate storage tank boil-off losses for long term missions, to economize ground pad storage and transfer operations, and to expand operational and architectural operations at destination. This paper organizes Cryogenic Fluid Management Project technology efforts according to Exploration Architecture target areas, and discusses the scope of trade studies, analytical modeling, and test efforts presently underway, as well as future plans, to address those target areas. The target areas are: liquid methane/liquid oxygen for propelling the Altair Lander Ascent Stage, liquid hydrogen/liquid oxygen for propelling the Altair Lander Descent Stage and Ares V Earth Departure Stage, liquefaction, zero boil-off, and propellant scavenging for Lunar Surface Systems, cold helium and zero boil-off technologies for Earth-Based Ground Operations, and architecture definition studies for long term storage and on-orbit transfer and pressurization of LH2, cryogenic Mars landing and ascent vehicles, and cryogenic production via in situ resource utilization on Mars.

  4. Cryogenic Quenching Process for Electronic Part Screening

    NASA Technical Reports Server (NTRS)

    Sheldon, Douglas J.; Cressler, John

    2011-01-01

    The use of electronic parts at cryogenic temperatures (less than 100 C) for extreme environments is not well controlled or developed from a product quality and reliability point of view. This is in contrast to the very rigorous and well-documented procedures to qualify electronic parts for mission use in the 55 to 125 C temperature range. A similarly rigorous methodology for screening and evaluating electronic parts needs to be developed so that mission planners can expect the same level of high reliability performance for parts operated at cryogenic temperatures. A formal methodology for screening and qualifying electronic parts at cryogenic temperatures has been proposed. The methodology focuses on the base physics of failure of the devices at cryogenic temperatures. All electronic part reliability is based on the bathtub curve, high amounts of initial failures (infant mortals), a long period of normal use (random failures), and then an increasing number of failures (end of life). Unique to this is the development of custom screening procedures to eliminate early failures at cold temperatures. The ability to screen out defects will specifically impact reliability at cold temperatures. Cryogenic reliability is limited by electron trap creation in the oxide and defect sites at conductor interfaces. Non-uniform conduction processes due to process marginalities will be magnified at cryogenic temperatures. Carrier mobilities change by orders of magnitude at cryogenic temperatures, significantly enhancing the effects of electric field. Marginal contacts, impurities in oxides, and defects in conductor/conductor interfaces can all be magnified at low temperatures. The novelty is the use of an ultra-low temperature, short-duration quenching process for defect screening. The quenching process is designed to identify those defects that will precisely (and negatively) affect long-term, cryogenic part operation. This quenching process occurs at a temperature that is at least

  5. Thermohydrodynamic Analysis of Cryogenic Liquid Turbulent Flow Fluid Film Bearings

    NASA Technical Reports Server (NTRS)

    San Andres, Luis

    1996-01-01

    This report describes a thermohydrodynamic analysis and computer programs for the prediction of the static and dynamic force response of fluid film bearings for cryogenic applications. The research performed addressed effectively the most important theoretical and practical issues related to the operation and performance of cryogenic fluid film bearings. Five computer codes have been licensed by the Texas A&M University to NASA centers and contractors and a total of 14 technical papers have been published.

  6. Cost-Efficient Storage of Cryogens

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Sass, J. P.; Nagy, Z.; Sojoumer, S. J.; Morris, D. L.; Augustynowicz, S. D.

    2007-01-01

    NASA's cryogenic infrastructure that supports launch vehicle operations and propulsion testing is reaching an age where major refurbishment will soon be required. Key elements of this infrastructure are the large double-walled cryogenic storage tanks used for both space vehicle launch operations and rocket propulsion testing at the various NASA field centers. Perlite powder has historically been the insulation material of choice for these large storage tank applications. New bulk-fill insulation materials, including glass bubbles and aerogel beads, have been shown to provide improved thermal and mechanical performance. A research testing program was conducted to investigate the thermal performance benefits as well as to identify operational considerations and associated risks associated with the application of these new materials in large cryogenic storage tanks. The program was divided into three main areas: material testing (thermal conductivity and physical characterization), tank demonstration testing (liquid nitrogen and liquid hydrogen), and system studies (thermal modeling, economic analysis, and insulation changeout). The results of this research work show that more energy-efficient insulation solutions are possible for large-scale cryogenic storage tanks worldwide and summarize the operational requirements that should be considered for these applications.

  7. Cost-Efficient Storage of Cryogens

    NASA Astrophysics Data System (ADS)

    Fesmire, J. E.; Sass, J. P.; Nagy, Z.; Sojourner, S. J.; Morris, D. L.; Augustynowicz, S. D.

    2008-03-01

    NASA's cryogenic infrastructure, which supports launch vehicle operations and propulsion testing, is reaching an age when major refurbishment is required. Key elements of this infrastructure are the large double-walled cryogenic storage tanks used for both space vehicle launch operations and rocket propulsion testing at various NASA field centers. Perlite powder has historically been the insulation material of choice for these applications, but new bulk-fill insulation materials, including glass bubbles and aerogel beads, have been shown to provide improved thermal and mechanical performance. Research was conducted on thermal performance to identify operational considerations and risks associated with using these new materials in large cryogenic storage tanks. The program was divided into three main areas: material testing (thermal conductivity and physical characterization), tank demonstration testing (liquid nitrogen and liquid hydrogen), and system studies (thermal modeling, granular physics, and insulation changeout). This research showed that more energy-efficient insulation solutions are possible for large-scale cryogenic storage tanks worldwide and summarized the operational requirements that should be considered for these applications.

  8. Cryogenic Capillary Screen Heat Entrapment

    NASA Technical Reports Server (NTRS)

    Bolshinskiy, L.G.; Hastings, L.J.; Stathman, G.

    2007-01-01

    Cryogenic liquid acquisition devices (LADs) for space-based propulsion interface directly with the feed system, which can be a significant heat leak source. Further, the accumulation of thermal energy within LAD channels can lead to the loss of sub-cooled propellant conditions and result in feed system cavitation during propellant outflow. Therefore, the fundamental question addressed by this program was: "To what degree is natural convection in a cryogenic liquid constrained by the capillary screen meshes envisioned for LADs.?"Testing was first conducted with water as the test fluid, followed by LN2 tests. In either case, the basic experimental approach was to heat the bottom of a cylindrical column of test fluid to establish stratification patterns measured by temperature sensors located above and below a horizontal screen barrier position. Experimentation was performed without barriers, with screens, and with a solid barrier. The two screen meshes tested were those typically used by LAD designers, "200x1400" and "325x2300", both with Twill Dutch Weave. Upon consideration of both the water and LN2 data it was concluded that heat transfer across the screen meshes was dependent upon barrier thermal conductivity and that the capillary screen meshes were impervious to natural convection currents.

  9. CRYOTE (Cryogenic Orbital Testbed) Concept

    NASA Technical Reports Server (NTRS)

    Gravlee, Mari; Kutter, Bernard; Wollen, Mark; Rhys, Noah; Walls, Laurie

    2009-01-01

    Demonstrating cryo-fluid management (CFM) technologies in space is critical for advances in long duration space missions. Current space-based cryogenic propulsion is viable for hours, not the weeks to years needed by space exploration and space science. CRYogenic Orbital TEstbed (CRYOTE) provides an affordable low-risk environment to demonstrate a broad array of critical CFM technologies that cannot be tested in Earth's gravity. These technologies include system chilldown, transfer, handling, health management, mixing, pressure control, active cooling, and long-term storage. United Launch Alliance is partnering with Innovative Engineering Solutions, the National Aeronautics and Space Administration, and others to develop CRYOTE to fly as an auxiliary payload between the primary payload and the Centaur upper stage on an Atlas V rocket. Because satellites are expensive, the space industry is largely risk averse to incorporating unproven systems or conducting experiments using flight hardware that is supporting a primary mission. To minimize launch risk, the CRYOTE system will only activate after the primary payload is separated from the rocket. Flying the testbed as an auxiliary payload utilizes Evolved Expendable Launch Vehicle performance excess to cost-effectively demonstrate enhanced CFM.

  10. Hydrodynamic Mixing of Ablator Material into the Compressed Fuel and Hot Spot of Direct-Drive DT Cryogenic Implosions

    NASA Astrophysics Data System (ADS)

    Regan, S. P.; Goncharov, V. N.; Epstein, R.; Betti, R.; Bonino, M. J.; Cao, D.; Collins, T. J. B.; Campbell, E. M.; Forrest, C. J.; Glebov, V. Yu.; Harding, D. R.; Marozas, J. A.; Marshall, F. J.; McKenty, P. W.; Sangster, T. C.; Stoeckl, C.; Luo, R. W.; Schoff, M. E.; Farrell, M.

    2016-10-01

    Hydrodynamic mixing of ablator material into the compressed fuel and hot spot of direct-drive DT cryogenic implosions is diagnosed using time-integrated, spatially resolved xray spectroscopy. The laser drive ablates most of the 8- μm-thick CH ablator, which is doped with trace amounts of Ge ( 0.5 at.) and surrounds the cryogenic DT layer. A small fraction of the ablator material is mixed into the compressed shell and the hot spot by the ablation-front Rayleigh-Taylor hydrodynamic instability seeded by laser imprint, the target mounting stalk, and surface debris. The amount of mix mass inferred from spectroscopic analysis of the Ge K-shell emission will be presented. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944. Part of this work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Exposure to Mission Relevant Doses of 1 GeV/Nucleon 56Fe Particles Leads to Impairment of Attentional Set-Shifting Performance in Socially Mature Rats

    PubMed Central

    Britten, Richard A.; Davis, Leslie K.; Jewell, Jessica S.; Miller, Vania D.; Hadley, Melissa M.; Sanford, Larry D.; Machida, Mayumi; Lonart, György

    2014-01-01

    Previous ground-based experiments have shown that cranial irradiation with mission relevant (20 cGy) doses of 1 GeV/nucleon 56Fe particles leads to a significant impairment in Attentional Set Shifting (ATSET) performance, a measure of executive function, in juvenile Wistar rats. However, the use of head only radiation exposure and the biological age of the rats used in that study may not be pertinent to determine the likelihood that ATSET will be impaired in Astronauts on deep space flights. In this study we have determined the impact that whole-body exposure to 10, 15 and 20 cGy of 1 GeV/nucleon 56Fe particles had on the ability (at three months post exposure) of socially mature (retired breeder) Wistar rats to conduct the attentional set-shifting paradigm. The current study has established that whole-body exposures to 15 and 20 (but not 10) cGy of 1 GeV/nucleon 56Fe particles results in the impairment of ATSET in both juvenile and socially mature rats. However, the exact nature of the impaired ATSET performance varied depending upon the age of the rats, whether whole-body versus cranial irradiation was used and the dose of 1 GeV/u 56Fe received. Exposure of juvenile rats to 20 cGy of 1 GeV/nucleon 56Fe particles led to a decreased ability to perform intra-dimensional shifting (IDS) irrespective of whether the rats received head only or whole-body exposures. Juvenile rats that received whole-body exposure also had a reduced ability to habituate to the assay and to complete intra-dimensional shifting reversal (IDR), whereas juvenile rats that received head only exposure had a reduced ability to complete compound discrimination reversal (CDR). Socially mature rats that received whole-body exposures to 10 cGy of 1 GeV/nucleon 56Fe particles exhibited no obvious decline in set-shifting performance; however those exposed to 15 and 20 cGy had a reduced ability to perform simple discrimination (SD) and compound discrimination (CD). Exposure to 20 cGy of 1 GeV/nucleon 56

  12. Cost effective use of liquid nitrogen in cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Mcintosh, Glen E.; Lombard, David S.; Martindale, David L.; Dunn, Robert P.

    1987-01-01

    A method of reliquefying from 12 to 19% of the nitrogen exhaust gas from a cryogenic wind tunnel has been developed. Technical feasibility and cost effectiveness of the system depends on performance of an innovative positive displacement expander which requires scale model testing to confirm design studies. The existing cryogenic system at the 0.3-m transonic cryogenic tunnel has been surveyed and extensive upgrades proposed. Upgrades are generally cost effective and may be implemented immediately since they are based on established technology.

  13. Oxygen chemisorption cryogenic refrigerator

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor)

    1987-01-01

    The present invention relates to a chemisorption compressor cryogenic refrigerator which employs oxygen to provide cooling at 60 to 100 K. The invention includes dual vessels containing an oxygen absorbent material, alternately heated and cooled to provide a continuous flow of high pressure oxygen, multiple heat exchangers for precooling the oxygen, a Joule-Thomson expansion valve system for expanding the oxygen to partially liquefy it and a liquid oxygen pressure vessel. The primary novelty is that, while it was believed that once oxygen combined with an element or compound the reaction could not reverse to release gaseous oxygen, in this case oxygen will indeed react in a reversible fashion with certain materials and will do so at temperatures and pressures which make it practical for incorporation into a cryogenic refrigeration system.

  14. Flexible cryogenic conduit

    DOEpatents

    Brindza, Paul Daniel; Wines, Robin Renee; Takacs, James Joseph

    1999-01-01

    A flexible and relatively low cost cryogenic conduit is described. The flexible cryogenic conduit of the present invention comprises a first inner corrugated tube with single braided serving, a second outer corrugated tube with single braided serving concentric with the inner corrugated tube, and arranged outwardly about the periphery of the inner corrugated tube and between the inner and outer corrugated tubes: a superinsulation layer; a one half lap layer of polyester ribbon; a one half lap layer of copper ribbon; a spirally wound refrigeration tube; a second one half lap layer of copper ribbon; a second one half lap layer of polyester ribbon; a second superinsulation layer; a third one half lap layer of polyester ribbon; and a spirally wound stretchable and compressible filament.

  15. Cryogenic Control System

    SciTech Connect

    Goloborod'ko, S.; /Fermilab

    1989-02-27

    The control system (CS) for the cryogenic arrangement of the DO Liquid Argon Calorimeter consists of a Texas instruments 560/565 Programmable Logical Controller (PLC), two remote bases with Remote Base Controllers and a corresponding set of input/output (I/O) modules, and a PC AST Premium 286 (IBM AT Compatible). The PLC scans a set of inputs and provides a set of outputs based on a ladder logic program and PID control loops. The inputs are logic or analog (current, voltage) signals from equipment status switches or transducers. The outputs are logic or analog (current or voltage) signals for switching solenoids and positioning pneumatic actuators. Programming of the PLC is preformed by using the TISOFT2/560/565 package, which is installed in the PC. The PC communicates to the PLC through a serial RS232 port and provides operator interface to the cryogenic process using Xpresslink software.

  16. Cryogenic treatment of gas

    DOEpatents

    Bravo, Jose Luis [Houston, TX; Harvey, III, Albert Destrehan; Vinegar, Harold J [Bellaire, TX

    2012-04-03

    Systems and methods of treating a gas stream are described. A method of treating a gas stream includes cryogenically separating a first gas stream to form a second gas stream and a third stream. The third stream is cryogenically contacted with a carbon dioxide stream to form a fourth and fifth stream. A majority of the second gas stream includes methane and/or molecular hydrogen. A majority of the third stream includes one or more carbon oxides, hydrocarbons having a carbon number of at least 2, one or more sulfur compounds, or mixtures thereof. A majority of the fourth stream includes one or more of the carbon oxides and hydrocarbons having a carbon number of at least 2. A majority of the fifth stream includes hydrocarbons having a carbon number of at least 3 and one or more of the sulfur compounds.

  17. Cryogenic support system

    DOEpatents

    Nicol, T.H.; Niemann, R.C.; Gonczy, J.D.

    1988-11-01

    A support system is disclosed for restraining large masses at very low or cryogenic temperatures. The support system employs a tie bar that is pivotally connected at opposite ends to an anchoring support member and a sliding support member. The tie bar extends substantially parallel to the longitudinal axis of the cold mass assembly, and comprises a rod that lengthens when cooled and a pair of end attachments that contract when cooled. The rod and end attachments are sized so that when the tie bar is cooled to cryogenic temperature, the net change in tie bar length is approximately zero. Longitudinal force directed against the cold mass assembly is distributed by the tie bar between the anchoring support member and the sliding support member. 7 figs.

  18. Cryogenic support system

    DOEpatents

    Nicol, Thomas H.; Niemann, Ralph C.; Gonczy, John D.

    1988-01-01

    A support system is disclosed for restraining large masses at very low or cryogenic temperatures. The support system employs a tie bar that is pivotally connected at opposite ends to an anchoring support member and a sliding support member. The tie bar extends substantially parallel to the longitudinal axis of the cold mass assembly, and comprises a rod that lengthens when cooled and a pair of end attachments that contract when cooled. The rod and end attachments are sized so that when the tie bar is cooled to cryogenic temperature, the net change in tie bar length is approximately zero. Longitudinal force directed against the cold mass assembly is distributed by the tie bar between the anchoring support member and the sliding support member.

  19. Stirling cycle cryogenic cooler

    NASA Technical Reports Server (NTRS)

    Gasser, M. G.; Sherman, A.; Studer, P. A.; Daniels, A.; Goldowsky, M. P. (Inventor)

    1983-01-01

    A long lifetime Stirling cycle cryogenic cooler particularly adapted for space applications is described. It consists of a compressor section centrally aligned end to end with an expansion section, and respectively includes a reciprocating compressor piston and displacer radially suspended in interconnecting cylindrical housings by active magnetic bearings and has adjacent reduced clearance regions so as to be in noncontacting relationship therewith and wherein one or more of these regions operate as clearance seals. The piston and displacer are reciprocated in their housings by linear drive motors to vary the volume of respectively adjacent compression and expansion spaces which contain a gaseous working fluid and a thermal regenerator to effect Stirling cycle cryogenic cooling.

  20. 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.

  1. Cryogenic Selective Surfaces

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert; Nurge, Mark

    2015-01-01

    Under our NASA Innovative Advanced Concepts (NIAC) project we have theoretically demonstrated a novel selective surface that reflects roughly 100 times more solar radiation than any other known coating. If this prediction holds up under experimental tests it will allow cryogenic temperatures to be reached in deep space even in the presence of the sun. It may allow LOX to be carried to the Moon and Mars. It may allow superconductors to be used in deep space without a refrigeration system.

  2. Hybrid Composite Cryogenic Tank Structure

    NASA Technical Reports Server (NTRS)

    DeLay, Thomas

    2011-01-01

    A hybrid lightweight composite tank has been created using specially designed materials and manufacturing processes. The tank is produced by using a hybrid structure consisting of at least two reinforced composite material systems. The inner composite layer comprises a distinct fiber and resin matrix suitable for cryogenic use that is a braided-sleeve (and/or a filamentwound layer) aramid fiber preform that is placed on a removable mandrel (outfitted with metallic end fittings) and is infused (vacuum-assisted resin transfer molded) with a polyurethane resin matrix with a high ductility at low temperatures. This inner layer is allowed to cure and is encapsulated with a filamentwound outer composite layer of a distinct fiber resin system. Both inner and outer layer are in intimate contact, and can also be cured at the same time. The outer layer is a material that performs well for low temperature pressure vessels, and it can rely on the inner layer to act as a liner to contain the fluids. The outer layer can be a variety of materials, but the best embodiment may be the use of a continuous tow of carbon fiber (T-1000 carbon, or others), or other high-strength fibers combined with a high ductility epoxy resin matrix, or a polyurethane matrix, which performs well at low temperatures. After curing, the mandrel can be removed from the outer layer. While the hybrid structure is not limited to two particular materials, a preferred version of the tank has been demonstrated on an actual test tank article cycled at high pressures with liquid nitrogen and liquid hydrogen, and the best version is an inner layer of PBO (poly-pphenylenebenzobisoxazole) fibers with a polyurethane matrix and an outer layer of T-1000 carbon with a high elongation epoxy matrix suitable for cryogenic temperatures. A polyurethane matrix has also been used for the outer layer. The construction method is ideal because the fiber and resin of the inner layer has a high strain to failure at cryogenic

  3. The Cryogenic Test Bed experiments: Cryogenic heat pipe flight experiment CRYOHP (STS-53). Cryogenic two phase flight experiment CRYOTP (STS-62). Cryogenic flexible diode flight experiment CRYOFD

    NASA Technical Reports Server (NTRS)

    Thienel, Lee; Stouffer, Chuck

    1995-01-01

    This paper presents an overview of the Cryogenic Test Bed (CTB) experiments including experiment results, integration techniques used, and lessons learned during integration, test and flight phases of the Cryogenic Heat Pipe Flight Experiment (STS-53) and the Cryogenic Two Phase Flight Experiment (OAST-2, STS-62). We will also discuss the Cryogenic Flexible Diode Heat Pipe (CRYOFD) experiment which will fly in the 1996/97 time frame and the fourth flight of the CTB which will fly in the 1997/98 time frame. The two missions tested two oxygen axially grooved heat pipes, a nitrogen fibrous wick heat pipe and a 2-methylpentane phase change material thermal storage unit. Techniques were found for solving problems with vibration from the cryo-collers transmitted through the compressors and the cold heads, and mounting the heat pipe without introducing parasitic heat leaks. A thermally conductive interface material was selected that would meet the requirements and perform over the temperature range of 55 to 300 K. Problems are discussed with the bi-metallic thermostats used for heater circuit protection and the S-Glass suspension straps originally used to secure the BETSU PCM in the CRYOTP mission. Flight results will be compared to 1-g test results and differences will be discussed.

  4. Cryogenic Fuel Tank Draining Analysis Model

    NASA Technical Reports Server (NTRS)

    Greer, Donald

    1999-01-01

    One of the technological challenges in designing advanced hypersonic aircraft and the next generation of spacecraft is developing reusable flight-weight cryogenic fuel tanks. As an aid in the design and analysis of these cryogenic tanks, a computational fluid dynamics (CFD) model has been developed specifically for the analysis of flow in a cryogenic fuel tank. This model employs the full set of Navier-Stokes equations, except that viscous dissipation is neglected in the energy equation. An explicit finite difference technique in two-dimensional generalized coordinates, approximated to second-order accuracy in both space and time is used. The stiffness resulting from the low Mach number is resolved by using artificial compressibility. The model simulates the transient, two-dimensional draining of a fuel tank cross section. To calculate the slosh wave dynamics the interface between the ullage gas and liquid fuel is modeled as a free surface. Then, experimental data for free convection inside a horizontal cylinder are compared with model results. Finally, cryogenic tank draining calculations are performed with three different wall heat fluxes to demonstrate the effect of wall heat flux on the internal tank flow field.

  5. Cryogenics Testbed Laboratory Flange Baseline Configuration

    NASA Technical Reports Server (NTRS)

    Acuna, Marie Lei Ysabel D.

    2013-01-01

    As an intern at Kennedy Space Center (KSC), I was involved in research for the Fluids and Propulsion Division of the NASA Engineering (NE) Directorate. I was immersed in the Integrated Ground Operations Demonstration Units (IGODU) project for the majority of my time at KSC, primarily with the Ground Operations Demonstration Unit Liquid Oxygen (GODU L02) branch of IGODU. This project was established to develop advancements in cryogenic systems as a part of KSC's Advanced Exploration Systems (AES) program. The vision of AES is to develop new approaches for human exploration, and operations in and beyond low Earth orbit. Advanced cryogenic systems are crucial to minimize the consumable losses of cryogenic propellants, develop higher performance launch vehicles, and decrease operations cost for future launch programs. During my internship, I conducted a flange torque tracking study that established a baseline configuration for the flanges in the Simulated Propellant Loading System (SPLS) at the KSC Cryogenics Test Laboratory (CTL) - the testing environment for GODU L02.

  6. Composite aerogel insulation for cryogenic liquid storage

    NASA Astrophysics Data System (ADS)

    Kyeongho, Kim; Hyungmook, Kang; Soojin, Shin; In Hwan, Oh; Changhee, Son; Hyung, Cho Yun; Yongchan, Kim; Sarng Woo, Karng

    2017-02-01

    High porosity materials such as aerogel known as a good insulator in a vacuum range (10-3 ∼ 1 Torr) was widely used to storage and to transport cryogenic fluids. It is necessary to be investigated the performance of aerogel insulations for cryogenic liquid storage in soft vacuum range to atmospheric pressure. A one-dimensional insulating experimental apparatus was designed and fabricated to consist of a cold mass tank, a heat absorber and an annular vacuum space with 5-layer (each 10 mm thickness) of the aerogel insulation materials. Aerogel blanket for cryogenic (used maximum temperature is 400K), aerogel blanket for normal temperature (used maximum temperature is 923K), and combination of the two kinds of aerogel blankets were 5-layer laminated between the cryogenic liquid wall and the ambient wall in vacuum space. Also, 1-D effective thermal conductivities of the insulation materials were evaluated by measuring boil-off rate from liquid nitrogen and liquid argon. In this study, the effective thermal conductivities and the temperature-thickness profiles of the two kinds of insulators and the layered combination of the two different aerogel blankets were presented.

  7. Surface Tension Confines Cryogenic Liquid

    NASA Technical Reports Server (NTRS)

    Castles, Stephen H.; Schein, Michael E.

    1989-01-01

    New type of Dewar provides passive, constant-temperature cryogenic cooling for scientific instruments under normal-to low-gravity conditions. Known as Surface-Tension-Contained Liquid Cryogen Cooler (STCLCC), keeps liquid cryogen in known location inside the Dewar by trapping liquid inside spongelike material. Unique sponge material fills most of volume of inner tank. Sponge is all-silica, open-cell material similar to that used for Space Shuttle thermal-protection tiles.

  8. Adhesive Bonding Characterization of Composite Joints for Cryogenic Usage

    NASA Technical Reports Server (NTRS)

    Graf, Neil A.; Schieleit, Gregory F.; Biggs, Robert

    2000-01-01

    The development of polymer composite cryogenic tanks is a critical step in creating the next generation of launch vehicles. Future reusable launch vehicles need to minimize the gross liftoff weight (GLOW). This weight reduction is possible due to the large reduction in weight that composite materials can provide over current aluminum technology. In addition to composite technology, adhesively bonded joints potentially have several benefits over mechanically fastened joints, such as weight savings and cryogenic fluid containment. Adhesively bonded joints may be used in several areas of these cryogenic tanks, such as in lobe-to-lobe joints (in a multi-lobe concept), skirt-to-tank joint, strut-to-tank joint, and for attaching stringers and ring frames. The bonds, and the tanks themselves, must be able to withstand liquid cryogenic fuel temperatures that they contain. However, the use of adhesively bonded composite joints at liquid oxygen and hydrogen temperatures is largely unknown and must be characterized. Lockheed Martin Space Systems Company, Michoud Operations performed coupon-level tests to determine effects of material selection, cure process parameters, substrate surface preparation, and other factors on the strength of these composite joints at cryogenic temperatures. This led to the selection of a material and process that would be suitable for a cryogenic tank. KEY WORDS: Composites, Adhesive Bonding, Cryogenics

  9. First Cryogenic Tests with Jlab's New Upgrade cavities

    SciTech Connect

    Peter Kneisel; Gianluigi Ciovati; Juergen Halbritter; Ganapati Rao Myneni; Jacek Sekutowicz; Genfa Wu

    2004-08-01

    Two types of 7-cell cavities have been developed for the upgrade of CEBAF to 12 GeV. The High Gradient type (HG) has been optimized with respect to the ratio of E{sub peak}/E{sub acc}. The Low Loss (LL) type has optimized shunt impedance and improved geometric factor. Each cavity type features four DESY-type coaxial Higher Order Mode (HOM) couplers and a waveguide input coupler. Design goals for these cavities have been set to E{sub acc} = 20 MV/m with an intrinsic Q{sub o} of 8 {center_dot} 10{sup 9} at 2.05 K. A niobium prototype of each cavity has been fabricated at JLab and both cavities have been evaluated at cryogenic temperatures after appropriate surface treatment. In addition, pressure sensitivity as well as Lorentz force detuning were evaluated. The damping of approximately 20 HOMs has been measured to verify the room temperature data. Several single cell cavities were tested in addition to multi cell cavities. We present in this contribution a summary of tests performed on the prototypes of the proposed cavities.

  10. Cryogenic Fluid Management Technologies for Advanced Green Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Motil, Susan M.; Meyer, Michael L.; Tucker, Stephen P.

    2007-01-01

    In support of the Exploration Vision for returning to the Moon and beyond, NASA and its partners are developing and testing critical cryogenic fluid propellant technologies that will meet the need for high performance propellants on long-term missions. Reliable knowledge of low-gravity cryogenic fluid management behavior is lacking and yet is critical in the areas of tank thermal and pressure control, fluid acquisition, mass gauging, and fluid transfer. Such knowledge can significantly reduce or even eliminate tank fluid boil-off losses for long term missions, reduce propellant launch mass and required on-orbit margins, and simplify vehicle operations. The Propulsion and Cryogenic Advanced Development (PCAD) Project is performing experimental and analytical evaluation of several areas within Cryogenic Fluid Management (CFM) to enable NASA's Exploration Vision. This paper discusses the status of the PCAD CFM technology focus areas relative to the anticipated CFM requirements to enable execution of the Vision for Space Exploration.

  11. Impaired Spatial Memory Performance in Adult Wistar Rats Exposed to Low (5-20 cGy) Doses of 1 GeV/n (56)Fe Particles.

    PubMed

    Britten, Richard A; Jewell, Jessica S; Miller, Vania D; Davis, Leslie K; Hadley, Melissa M; Wyrobek, Andrew J

    2016-03-01

    Prolonged deep space missions to planets and asteroids will expose astronauts to galactic cosmic radiation, comprised of low-linear energy transfer (LET) ionizing radiations, high-energy protons and high-Z and energy (HZE) particles, such as (56)Fe nuclei. In prior studies with rodents exposed to HZE particle radiation at doses likely to be encountered during deep space missions (<20 cGy) investigators reported impaired hippocampal-dependent neurocognitive performance and further observed substantial variation among the irradiated animals in neurocognitive impairment, ranging from no observable effects to severe impairment. These findings point to the importance of incorporating quantitative measures of interindividual variations into next generation risk assessment models of radiation risks on neurocognition. In this study, 269 male proven breeder Wistar rats were exposed to 1 GeV/n (56)Fe at doses of 0, 5, 10, 15 and 20 cGy, and tested for spatial memory performance on the Barnes maze at three months after exposure. The radiation response data were compared using changes in mean cohort performance and by the proportion of poor responders using the performance benchmark of two standard deviations below the mean value among the sham-irradiated cohort. Acute exposures to mission-relevant doses of 1 GeV/n (56)Fe reduced the mean spatial memory performance at three months after exposure (P < 0.002) and increased the proportions of poor performers, 2- to 3-fold. However, a substantial fraction of animals in all exposure cohorts showed no detectable change in performance, compared to the distribution of sham-irradiated animals. Our findings suggest that individualized metrics of susceptibility or resistance to radiation-induce changes in neurocognitive performance will be advantageous to the development of probabilistic risk assessment models for HZE-induced neurocognitive impairment.

  12. Noise performance at cryogenic temperatures at AlGaAs/InGaAs HEMT's with 0.15- mu m T-shaped WSi/sub x/ gates

    NASA Astrophysics Data System (ADS)

    Joshin, K.; Mimino, Y.; Ohmura, S.; Hirachi, Y.

    1992-03-01

    T-shaped 0.15-μm WSix gate HEMTs have been fabricated on AlGaAs/InGaAs MBE wafers. Their S-parameters, output noise spectral density Pno, and noise temperatures T e at cryogenic temperatures, were measured. The current gain cutoff frequency fT increases from 61 GHz at 295 K to 87 GHz at 90 K. Pno and Te measurements indicate that the hot-electron effect is noticeable at low temperatures at high drain current. At 30 GHz, the noise temperature is 19±3 K with an associated gain of 10.4 dB at the physical temperature of 20 K. The results demonstrate the great potential of AlGaAs/InGaAs HEMTs for low-temperature applications.

  13. Capillary acquisition devices for high-performance vehicles: Executive summary. [evaluation of cryogenic propellant management techniques using the centaur launch vehicle

    NASA Technical Reports Server (NTRS)

    Blatt, M. H.; Bradshaw, R. D.; Risberg, J. A.

    1980-01-01

    Technology areas critical to the development of cryogenic capillary devices were studied. Passive cooling of capillary devices was investigated with an analytical and experimental study of wicking flow. Capillary device refilling with settled fluid was studied using an analytical and experimental program that resulted in successful correlation of a versatile computer program with test data. The program was used to predict Centaur D-1S LO2 and LH2 start basket refilling. Comparisons were made between the baseline Centaur D-1S propellant feed system and feed system alternatives including systems using capillary devices. The preferred concepts from the Centaur D-1S study were examined for APOTV and POTV vehicles for delivery and round trip transfer of payloads between LEO and GEO. Mission profiles were determined to provide propellant usage timelines and the payload partials were defined.

  14. The Nuclear Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Kim, Tony; Emrich, William J.; Hickman, Robert R.; Broadway, Jeramie W.; Gerrish, Harold P.; Doughty, Glen; Belvin, Anthony; Borowski, Stanley K.; Scott, John

    2014-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progres made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP).

  15. The Nuclear Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Kim, Tony; Emrich, William J.; Hickman, Robert R.; Broadway, Jeramie W.; Gerrish, Harold P.; Doughty, Glen; Belvin, Anthony; Borowski, Stanley K.; Scott, John

    2014-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP). Nuclear propulsion can be affordable and viable compared to other propulsion systems and must overcome a biased public fear due to hyper-environmentalism and a false perception of radiation and explosion risk.

  16. Photomultiplier Tubes at Cryogenic Temperatures

    NASA Astrophysics Data System (ADS)

    Saunders, Nathan

    2016-09-01

    Liquid noble gas scintillators are widely used in experiments searching for physics beyond the Standard Model. Photomultiplier Tubes (PMTs) working at cryogenic temperatures have been developed as the primary light readout device in those experiments. Three PMTs from Hamamatsu Photonics K.K. (R6041, R11065, and R8520) have been systematically characterized at liquid nitrogen temperature. The high voltage dividing circuits for two of the PMTs were custom-built to make sure there is similar performance at both room and liquid nitrogen temperatures. Their dark count rates at both temperatures were measured. Also measured were their single photoelectron responses at both temperatures using 300, 340, 370, and 420 nm LEDs. The intention is to couple these PMTs directly with inorganic scintillators at liquid nitrogen temperature to achieve high light yeilds for rare-event searches.

  17. A Cryogenic Infrared Calibration Target

    NASA Technical Reports Server (NTRS)

    Wollack, E. J.; Kinzer, R. E., Jr.; Rinehart, S. A.

    2014-01-01

    A compact cryogenic calibration target is presented that has a peak diffuse reflectance, R < or = 0.003, from 800 to 4800/cm (12 - 2 microns ). Upon expanding the spectral range under consideration to 400-10,000/ cm-1 (25 - 1 microns) the observed performance gracefully degrades to R < or = 0.02 at the band edges. In the implementation described, a high-thermal-conductivity metallic substrate is textured with a pyramidal tiling and subsequently coated with a thin lossy dielectric coating that enables high absorption and thermal uniformity across the target. The resulting target assembly is lightweight, has a low-geometric profile, and has survived repeated thermal cycling from room temperature to approx.4 K. Basic design considerations, governing equations, and test data for realizing the structure described are provided. The optical properties of selected absorptive materials-Acktar Fractal Black, Aeroglaze Z306, and Stycast 2850 FT epoxy loaded with stainless steel powder-are characterized and presented

  18. Cryogenic thermal control technology summaries

    NASA Technical Reports Server (NTRS)

    Stark, J. A.; Leonhard, K. E.; Bennett, F. O., Jr.

    1974-01-01

    A summarization and categorization is presented of the pertinent literature associated with cryogenic thermal control technology having potential application to in-orbit fluid transfer systems and/or associated space storage. Initially, a literature search was conducted to obtain pertinent documents for review. Reports determined to be of primary significance were summarized in detail. Each summary, where applicable, consists of; (1) report identification, (2) objective(s) of the work, (3) description of pertinent work performed, (4)major results, and (5) comments of the reviewer (GD/C). Specific areas covered are; (1) multilayer insulation of storage tanks with and without vacuum jacketing, (2) other insulation such as foams, shadow shields, microspheres, honeycomb, vent cooling and composites, (3) vacuum jacketed and composite fluid lines, and (4) low conductive tank supports and insulation penetrations. Reports which were reviewed and not summarized, along with reasons for not summarizing, are also listed.

  19. The integration of cryogenic cooling systems with superconducting electronic systems

    SciTech Connect

    Green, Michael A.

    2003-07-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  20. Search for 0 νββ with CUORE: experiment and cryogenic systems overview

    NASA Astrophysics Data System (ADS)

    Drobizhev, Alexey; Cuore Collaboration

    2016-03-01

    CUORE--the Cryogenic Underground Observatory for Rare Events--is a search for the neutrinoless double beta decay of 130Te based at the Gran Sasso National Laboratories in Italy. The experiment, currently in its final stages of commissioning, is expected to begin data taking in 2016 and eventually be sensitive to a ~1026 y half life after a 5 y live time. The detector consists of an array of 988 5 ×5 ×5 cm3 TeO2 crystals (204 kg isotope mass) operated as bolometers at ~10 mK temperatures with Ge NTD readout. Running a ~1 t, ~1 m3 detector at such temperatures necessitated the design and construction of the world's largest and most powerful dilution refrigerator, capable of reaching temperatures <10 mK and producing ~ 2 mW of cooling power at 100 mK. The cryostat is optimized for noise and vibration isolation, as well as radiopurity. We report the expected and observed performance of the CUORE experiment and, in particular, its cryogenic systems. This work is supported by the INFN, DOE, NSF, the Alfred P. Sloan Foundation, the University of Wisconsin Foundation, and Yale University.

  1. HESS-II reconstruction strategy and performance in the low-energy (20-150 GeV) domain

    SciTech Connect

    Becherini, Y.; Djannati-Atai, A.; Punch, M.; Bernloehr, K.; Ehlert, S.; Masbou, J.; Moulin, E.

    2008-12-24

    In mid-2009 a notable upgrade of the H.E.S.S. telescope system will take place: a new telescope with a 600 m{sup 2} mirror area and very-high-resolution camera (0.07 deg.) will be positioned at the centre of the present configuration, with the aim of lowering the threshold and enhance its sensitivity in the 100 GeV to several TeV energy range. HESS-II will permit the investigation of the lower energy {gamma}-ray spectra in various cosmic accelerators, giving information on the origin of the {gamma}-rays observed, and will detect AGNs with a redshift greater than 0.2 (being less affected by absorption by Extragalactic Background Light--EBL--in this energy range) and will search for new classes of very high energy {gamma}-ray emitters (pulsars, microquasars, GRB, and dark matter candidates)

  2. Hierarchical Structural Evolution of Zn2GeO4 in Binary Solvent and Its Effect on Li-ion Storage Performance.

    PubMed

    Liu, Wei; Zhou, Tengfei; Zheng, Yang; Liu, Jianwen; Feng, Chuanqi; Shen, Yue; Huang, Yunhui; Guo, Zaiping

    2017-03-22

    Zinc germinate (Zn2GeO4) with a hierarchical structure was successfully synthesized in a binary ethylenediamine/water (En/H2O) solvent system by wet chemistry methods. The morphological evolution process of the Zn2GeO4 was investigated in detail by tuning the ratio of En to H2O in different solvent systems, and a series of compounds with awl-shaped, fascicular, and cross-linked hierarchical structures was obtained and employed as anode materials in lithium-ion batteries. The materials with fascicular structure exhibited excellent electrochemical performance, and a specific reversible capacity of 1034 mA h g(-1) was retained at a current density of 0.5 A g(-1) after 160 cycles. In addition, the as-prepared nanostructured electrode also delivered impressive rate capability of 315 mA h g(-1) at the current density of 10 A g(-1). The remarkable electrochemical performances could be ascribed to the following aspects. First, each unit in the three-dimensional fascicular structure can effectively buffer the volume expansions during the Li(+) extraction/insertion process, accommodate the strain induced by the volume variation, and stabilize its whole configuration. Meanwhile, the small fascicular units can enlarge the electrode/electrolyte contact area and form an integrated interlaced conductive network which provides continuous electron/ion pathways.

  3. Long term cryogenic storage facility systems study

    NASA Technical Reports Server (NTRS)

    Schuster, John R.

    1987-01-01

    The Long Term Cryogenic Storage Facility Systems Study (LTCSFSS) is a Phase A study of a large capacity propellant depot for the space based, cryogenic orbital transfer vehicle. The study is being performed for Marshall Space Flight Center by General Dynamics Space Systems Division and has five principal objectives: (1) Definition of preliminary concept designs for four storage facility concepts; (2) Selection of preferred concepts through the application of trade studies to candidate propellant management system components; (3) Preparation of a conceptual design for an orbital storage facility; (4) Development of supporting research and technology requirements; and (5) Development of a test program to demonstrate facility performance. The initial study has been completed, and continuation activities are just getting under way to provide greater detail in key areas and accommodate changes in study guidelines and assumptions.

  4. Cryogenic Flow Sensor

    NASA Technical Reports Server (NTRS)

    Justak, John

    2010-01-01

    An acousto-optic cryogenic flow sensor (CFS) determines mass flow of cryogens for spacecraft propellant management. The CFS operates unobtrusively in a high-pressure, high-flowrate cryogenic environment to provide measurements for fluid quality as well as mass flow rate. Experimental hardware uses an optical plane-of-light (POL) to detect the onset of two-phase flow, and the presence of particles in the flow of water. Acousto-optic devices are used in laser equipment for electronic control of the intensity and position of the laser beam. Acousto-optic interaction occurs in all optical media when an acoustic wave and a laser beam are present. When an acoustic wave is launched into the optical medium, it generates a refractive index wave that behaves like a sinusoidal grating. An incident laser beam passing through this grating will diffract the laser beam into several orders. Its angular position is linearly proportional to the acoustic frequency, so that the higher the frequency, the larger the diffracted angle. If the acoustic wave is traveling in a moving fluid, the fluid velocity will affect the frequency of the traveling wave, relative to a stationary sensor. This frequency shift changes the angle of diffraction, hence, fluid velocity can be determined from the diffraction angle. The CFS acoustic Bragg grating data test indicates that it is capable of accurately determining flow from 0 to 10 meters per second. The same sensor can be used in flow velocities exceeding 100 m/s. The POL module has successfully determined the onset of two-phase flow, and can distinguish vapor bubbles from debris.

  5. Optical Detection Of Cryogenic Leaks

    NASA Technical Reports Server (NTRS)

    Wyett, Lynn M.

    1988-01-01

    Conceptual system identifies leakage without requiring shutdown for testing. Proposed device detects and indicates leaks of cryogenic liquids automatically. Detector makes it unnecessary to shut equipment down so it can be checked for leakage by soap-bubble or helium-detection methods. Not necessary to mix special gases or other materials with cryogenic liquid flowing through equipment.

  6. Refrigerated cryogenic envelope

    DOEpatents

    Loudon, John D.

    1976-11-16

    An elongated cryogenic envelope including an outer tube and an inner tube coaxially spaced within said inner tube so that the space therebetween forms a vacuum chamber for holding a vacuum. The inner and outer tubes are provided with means for expanding or contracting during thermal changes. A shield is located in the vacuum chamber intermediate the inner and outer tubes; and, a refrigeration tube for directing refrigeration to the shield is coiled about at least a portion of the inner tube within the vacuum chamber to permit the refrigeration tube to expand or contract along its length during thermal changes within said vacuum chamber.

  7. FRIB cryogenic distribution system

    SciTech Connect

    Ganni, Venkatarao; Dixon, Kelly D.; Laverdure, Nathaniel A.; Knudsen, Peter N.; Arenius, Dana M.; Barrios, Matthew N.; Jones, S.; Johnson, M.; Casagrande, Fabio

    2014-01-01

    The Michigan State University Facility for Rare Isotope Beams (MSU-FRIB) helium distribution system has been revised to include bayonet/warm valve type disconnects between each cryomodule and the transfer line distribution system, similar to the Thomas Jefferson National Accelerator Facility (JLab) and the Spallation Neutron Source (SNS) cryogenic distribution systems. The heat loads at various temperature levels and some of the features in the design of the distribution system are outlined. The present status, the plans for fabrication, and the procurement approach for the helium distribution system are also included.

  8. Cryogenic support member

    DOEpatents

    Niemann, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

    1987-01-01

    A cryogenic support member is comprised of a non-metallic rod having a depression in at least one end and a metallic end connection assembled to the rod. The metallic end connection comprises a metallic plug which conforms to the shape and is disposed in the depression and a metallic sleeve is disposed over the rod and plug. The plug and the sleeve are shrink-fitted to the depression in the rod to form a connection good in compression, tension and bending.

  9. Cryogenic Propellant Scavenging

    NASA Technical Reports Server (NTRS)

    Louie, B.; Kemp, N. J.; Daney, D. E.

    1985-01-01

    A detailed description of a computer model that has been developed for assessing the feasibility of low g cryogen propellant scavenging from the space shuttle External Tank (ET) is given. Either pump-assisted or pressure-induced propellant transfer may be selected. The program will accept a wide range of input variables, including the fuel to be transferred (LOX or LH2), heat leaks, tank temperatures, and piping and equipment specifications. The model has been parametrically analyzed to determine initial design specification for the system.

  10. Device applications of cryogenic optical refrigeration

    NASA Astrophysics Data System (ADS)

    Melgaard, Seth D.; Seletskiy, Denis V.; Epstein, Richard I.; Alden, Jay V.; Sheik-Bahae, Mansoor

    2014-02-01

    With the coldest solid-state temperatures (ΔT <185K from 300K) achievable by optical refrigeration, it is now timely to apply this technology to cryogenic devices. Along with thermal management and pump absorption, this work addresses the most key engineering challenge of transferring cooling power to the payload while efficiently rejecting optical waste-heat fluorescence. We discuss our optimized design of such a thermal link, which shows excellent performance in optical rejection and thermal properties.

  11. Installation and commissioning of a cryogen distribution system for the TPS project

    NASA Astrophysics Data System (ADS)

    Tsai, H. H.; Hsiao, F. Z.; Li, H. C.; Lin, M. C.; Wang, C.; Liao, W. R.; Lin, T. F.; Chiou, W. S.; Chang, S. H.; Chuang, P. S. D.

    2016-07-01

    A cryogen distribution system was installed and commissioned to transfer liquid nitrogen (LN2) and liquid helium (LHe) from storage dewars to superconducting radio-frequency (SRF) cavities for the 3-GeV Taiwan Photon Source (TPS) project. The cryogen distribution system comprises one distribution valve box (DVB), four control valve boxes (CVB) and seven sections of multichannel transfer line (MCL). The DVB distributes the LHe and LN2 to the CVB, and then to the SRF cavities through independent vacuum-jacketed transfer lines. The vaporized GHe and GN2 from the cryomodules are collected via the MCL. The cryogen distribution system was installed and commissioned from October 2014 to the end of March 2015. This paper presents the installation, pre-commissioning and commissioning of the cryogen distribution system, and describes the heat load test. Thermal acoustic oscillation (TAO) was found in the GHe process line; this phenomenon and its solution are also presented and discussed.

  12. Biological Applications of Cryogenic Detectors

    SciTech Connect

    Friedrich, S

    2003-12-03

    High energy resolution and broadband efficiency are enabling the use of cryogenic detectors in biological research. Two areas where they have found initial application are X-ray absorption spectroscopy (XAS) and time-of-flight mass spectrometry (TOF-MS). In synchrotron-based fluorescence-detected XAS cryogenic detectors are used to examine the role of metals in biological systems by measuring their oxidation states and ligand symmetries. In time-of-flight mass spectrometry cryogenic detectors increase the sensitivity for biomolecule detection and identification for masses above {approx}50 kDa, and thus enable TOF-MS on large protein complexes or even entire viruses. More recently, cryogenic detectors have been proposed as optical sensors for fluorescence signals from biomarkers. We discuss the potential for cryogenic detectors in biological research, as well as the challenges the technology faces.

  13. Computed tomography of cryogenic cells

    SciTech Connect

    Schneider, Gerd; Anderson, E.; Vogt, S.; Knochel, C.; Weiss, D.; LeGros, M.; Larabell, C.

    2001-08-30

    Due to the short wavelengths of X-rays and low numerical aperture of the Fresnel zone plates used as X-ray objectives, the depth of field is several microns. Within the focal depth, imaging a thick specimen is to a good approximation equivalent to projecting the specimen absorption. Therefore, computed tomography based on a tilt series of X-ray microscopic images can be used to reconstruct the local linear absorption coefficient and image the three-dimensional specimen structure. To preserve the structural integrity of biological objects during image acquisition, microscopy is performed at cryogenic temperatures. Tomography based on X-ray microscopic images was applied to study the distribution of male specific lethal 1 (MSL-1), a nuclear protein involved in dosage compensation in Drosophila melanogaster, which ensures that males with single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. Tomographic reconstructions of X-ray microscopic images were used to compute the local three-dimensional linear absorption coefficient revealing the arrangement of internal structures of Drosophila melanogaster cells. Combined with labelling techniques, nanotomography is a new technique to study the 3D distribution of selected proteins inside whole cells. We want to improve this technique with respect to resolution and specimen preparation. The resolution in the reconstruction can be significantly improved by reducing the angular step size to collect more viewing angles, which requires an automated data acquisition. In addition, fast-freezing with liquid ethane instead of cryogenic He gas will be applied to improve the vitrification of the hydrated samples. We also plan to apply cryo X-ray nanotomography in order to study different types of cells and their nuclear protein distributions.

  14. Cryogenic Fluid Technologies for Long Duration In-Space Operations

    NASA Technical Reports Server (NTRS)

    Motil, Susan M.; Tramel, Terri L.

    2008-01-01

    Reliable knowledge of low-gravity cryogenic fluid management behavior is lacking and yet is critical in the areas of storage, distribution, and low-gravity propellant management. The Vision for Space Exploration mission objectives will require the use of high performance cryogenic propellants (hydrogen, oxygen, and methane). Additionally, lunar missions will require success in storing and transferring liquid and gas commodities on the surface. The fundamental challenges associated with the in-space use of cryogens are their susceptibility to environmental heat, their complex thermodynamic and fluid dynamic behavior in low gravity and the uncertainty of the position of the liquid-vapor interface if the propellants are not settled. The Cryogenic Fluid Management (CFM) project is addressing these issues through ground testing and analytical model development, and has crosscutting applications and benefits to virtually all missions requiring in-space operations with cryogens. Such knowledge can significantly reduce or even eliminate tank fluid boil-off losses for long term missions, reduce propellant launch mass and on-orbit margins, and simplify vehicle operations. The Cryogenic Fluid Management (CFM) Project is conducting testing and performing analytical evaluation of several areas to enable NASA s Exploration Vision. This paper discusses the content and progress of the technology focus areas within CFM.

  15. Neutron Detection with a Cryogenic Spectrometer

    SciTech Connect

    Bell, Z.W.; Lamberti, V.E.; Carpenter, D.A.; Cristy, S.S.

    2003-06-23

    Cryogenic calorimeters are used for x-ray detection because of their exquisite energy resolution and have found application in x-ray astronomy, and the search for dark matter. These devices operate by detecting the heat pulse produced by ionization in an absorber cooled to temperatures below 1 K. Such temperatures are needed to lower the absorber's heat capacity to the point that the deposition of even a few eV results in a measurable temperature excursion. Typical absorbers for dark matter measurements are massive Si or Ge crystals, and, with Ge, have achieved a resolution of 650 eV at 10 keV. Chow, et al., report the measurement of the 60 keV emission from {sup 241}Am with 230 eV resolution using a superconducting tin absorber. Cunningham, et al., also using a superconducting tin absorber, have recently reported a four-fold improvement over Chow. With such results being reported from the x- and gamma-ray world it is natural to examine the possibilities for cryogenic neutron spectroscopy. Such a detector would operate by detecting the heat pulses caused by neutron capture and scattering. To date, {sup 6}LiF has been the absorber of choice because relatively large crystals can be grown, and it is an insulating material with low heat capacity. Silver reports the fabrication of a {sup 6}LiF spectrometer operating at 328 mK and achieving a resolution of 39 keV. De Marcillac reports the fabrication of a spectrometer operating at 80 mK and achieving 16 keV resolution when bombarded with 5 MeV alpha particles. In this paper, we report preliminary results with a TiB{sub 2} absorber exposed to thermal neutrons. In contrast to lithium, whose chemistry selects for LiF as the absorber, boron offers a rich chemistry from which to select materials with high boron content. We will discuss the considerations governing the choice of absorber material as well as the basic considerations needed to understand a cryogenic spectrometer. The capture and scattering reactions in boron and

  16. Evaluation of COTS SiGe, SOI, and Mixed Signal Electronic Parts for Extreme Temperature Use in NASA Missions

    NASA Technical Reports Server (NTRS)

    Patterson, Richard L.; Hammoud, Ahmad

    2010-01-01

    The NASA Electronic Parts and Packaging (NEPP) Program sponsors a task at the NASA Glenn Research Center titled "Reliability of SiGe, SOI, and Advanced Mixed Signal Devices for Cryogenic Space Missions." In this task COTS parts and flight-like are evaluated by determining their performance under extreme temperatures and thermal cycling. The results from the evaluations are published on the NEPP website and at professional conferences in order to disseminate information to mission planners and system designers. This presentation discusses the task and the 2010 highlights and technical results. Topics include extreme temperature operation of SiGe and SOI devices, all-silicon oscillators, a floating gate voltage reference, a MEMS oscillator, extreme temperature resistors and capacitors, and a high temperature silicon operational amplifier.

  17. Cryogenic Piezoelectric Actuator

    NASA Technical Reports Server (NTRS)

    Jiang, Xiaoning; Cook, William B.; Hackenberger, Wesley S.

    2009-01-01

    In this paper, PMN-PT single crystal piezoelectric stack actuators and flextensional actuators were designed, prototyped and characterized for space optics applications. Single crystal stack actuators with footprint of 10 mm x10 mm and the height of 50 mm were assembled using 10 mm x10mm x0.15mm PMN-PT plates. These actuators showed stroke > 65 - 85 microns at 150 V at room temperature, and > 30 microns stroke at 77 K. Flextensional actuators with dimension of 10mm x 5 mm x 7.6 mm showed stroke of >50 microns at room temperature at driving voltage of 150 V. A flextensional stack actuator with dimension of 10 mm x 5 mm x 47 mm showed stroke of approx. 285 microns at 150 V at room temperature and > 100 microns at 77K under driving of 150 V should be expected. The large cryogenic stroke and high precision of these actuators are promising for cryogenic optics applications.

  18. Cryogenic fluid management experiment

    NASA Technical Reports Server (NTRS)

    Eberhardt, R. N.; Bailey, W. J.; Fester, D. A.

    1981-01-01

    The cryogenic fluid management experiment (CFME), designed to characterize subcritical liquid hydrogen storage and expulsion in the low-q space environment, is discussed. The experiment utilizes a fine mesh screen fluid management device to accomplish gas-free liquid expulsion and a thermodynamic vent system to intercept heat leak and control tank pressure. The experiment design evolved from a single flight prototype to provision for a multimission (up to 7) capability. A detailed design of the CFME, a dynamic test article, and dedicated ground support equipment were generated. All materials and parts were identified, and components were selected and specifications prepared. Long lead titanium pressurant spheres and the flight tape recorder and ground reproduce unit were procured. Experiment integration with the shuttle orbiter, Spacelab, and KSC ground operations was coordinated with the appropriate NASA centers, and experiment interfaces were defined. Phase 1 ground and flight safety reviews were conducted. Costs were estimated for fabrication and assembly of the CFME, which will become the storage and supply tank for a cryogenic fluid management facility to investigate fluid management in space.

  19. Cryogenics maintenance strategy

    NASA Astrophysics Data System (ADS)

    Cruzat, Fabiola

    2012-09-01

    ALMA is an interferometer composed of 66 independent systems, with specific maintenance requirements for each subsystem. To optimize the observation time and reduce downtime maintenance, requirements are very demanding. One subsystem with high maintenance efforts is cryogenics and vacuum. To organize the maintenance, the Cryogenic and Vacuum department is using and implementing different tools. These are monitoring and problem reporting systems and CMMS. This leads to different maintenance approaches: Preventive Maintenance, Corrective Maintenance and Condition Based Maintenance. In order to coordinate activities with other departments the preventive maintenance schedule is kept as flexible as systems allow. To cope with unavoidable failures, the team has to be prepared to work under any condition with the spares on time. Computerized maintenance management system (CMMS) will help to manage inventory control for reliable spare part handling, the correct record of work orders and traceability of maintenance activities. For an optimized approach the department is currently evaluating where preventive or condition based maintenance applies to comply with the individual system demand. Considering the change from maintenance contracts to in-house maintenance will help to minimize costs and increase availability of parts. Due to increased number of system and tasks the cryo team needs to grow. Training of all staff members is mandatory, in depth knowledge must be built up by doing complex maintenance activities in the Cryo group, use of advanced computerized metrology systems.

  20. Innovative, High-Pressure, Cryogenic Control Valve: Short Face-to-Face, Reduced Cost

    NASA Technical Reports Server (NTRS)

    Wilkes, Karlin; Larsen, Ed; McCourt, Jackson

    2003-01-01

    A control valve that can throttle high-pressure cryogenic fluid embodies several design features that distinguish it over conventional valves designed for similar applications. Field and design engineers worked together to create a valve that would simplify installation, trim changes, and maintenance, thus reducing overall cost. The seals and plug stem packing were designed to perform optimally in cryogenic temperature ranges. Unlike conventional high-pressure cryogenic valves, the trim size can be changed independent of the body.

  1. Cryogenic Boil-Off Reduction System

    NASA Astrophysics Data System (ADS)

    Plachta, David W.; Guzik, Monica C.

    2014-03-01

    A computational model of the cryogenic boil-off reduction system being developed by NASA as part of the Cryogenic Propellant Storage and Transfer technology maturation project has been applied to a range of propellant storage tanks sizes for high-performing in-space cryogenic propulsion applications. This effort focuses on the scaling of multi-layer insulation (MLI), cryocoolers, broad area cooling shields, radiators, solar arrays, and tanks for liquid hydrogen propellant storage tanks ranging from 2 to 10 m in diameter. Component scaling equations were incorporated into the Cryogenic Analysis Tool, a spreadsheet-based tool used to perform system-level parametric studies. The primary addition to the evolution of this updated tool is the integration of a scaling method for reverse turbo-Brayton cycle cryocoolers, as well as the development and inclusion of Self-Supporting Multi-Layer Insulation. Mass, power, and sizing relationships are traded parametrically to establish the appropriate loiter period beyond which this boil-off reduction system application reduces mass. The projected benefit compares passive thermal control to active thermal control, where active thermal control is evaluated for reduced boil-off with a 90 K shield, zero boil-off with a single heat interception stage at the tank wall, and zero boil-off with a second interception stage at a 90 K shield. Parametric studies show a benefit over passive storage at loiter durations under one month, in addition to showing a benefit for two-stage zero boil-off in terms of reducing power and mass as compared to single stage zero boil-off. Furthermore, active cooling reduces the effect of varied multi-layer insulation performance, which, historically, has been shown to be significant.

  2. Bonding and Sealing Evaluations for Cryogenic Tanks

    NASA Technical Reports Server (NTRS)

    Glass, David E.

    1997-01-01

    Several different cryogenic tank concepts are being considered for reusable launch vehicles (RLV'S) . Though different tank concepts are being considered, many will require that the cryogenic insulation be evacuated and be bonded to a structure. In this work, an attempt was made to evaluate the effectiveness of maintaining a vacuum on a specimen where foam or honeycomb core was encased within Gr/Ep. In addition to these tests, flatwise adhesion pull off tests were performed at room temperature with PR 1664, EA 9394, FM-300, Crest 3170, and HT 435 adhesives. The materials bonded included Gr/Ep, Gr/BMI, Al, and stainless steel facesheets, and Ti honeycomb, Hexcel honeycomb, and Rohacell foam core materials.

  3. A cryogenic valve for spacecraft applications

    NASA Technical Reports Server (NTRS)

    Salerno, L. J.; Spivak, A. L.

    1982-01-01

    Space-compatible cryogenic valves are now required to operate between room and liquid helium temperatures. A remotely controllable cryogenic valve is described, which is made of bellows-type stainless steel and is operated by a miniature dc motor with integral gearset (485:1) at a nominal voltage of 28 Vdc. The power transmission provides a further reduction of 7.2:1 to give an overall gear ratio of nearly 3500:1, assuring reliability of operation at low temperatures. Valve performance (leak rate) data are presented at LN2, LHe, and SfHe temperatures at delivered torques of 18, 27, 31, and 35 N-m. At a closing torque of 31 N-m, a leak rate of 0.028 scc/sec was achieved at 2 K, while at a torque of 18 N-m the leak rate at 300 K was less than 3 x 10 to the -9th scc/sec.

  4. Cryogenics for ground based and space-borne instrumentation

    NASA Astrophysics Data System (ADS)

    Duband, L.

    In many space sciences project cryogenic detectors are essential for the accomplishment of the scientific objectives, offering unique advantages and unmatched performance. In addition several other components such as the optics can benefit from a cryogenic cooling which reduces the radiative loading. The Service des Basses Températ- ures (SBT) of CEA Grenoble has been involved in space cryogenics for over 20 years now and features a dedicated laboratory, the Cryocoolers and Space Cryogenics group. Various cryocoolers have been developed in the past and our fields of activity focus now on four main technologies: sorption coolers, multistage pulse tubes, adiabatic demagnetization refrigerators (ADR), and cryogenic loop heat pipes. In addition work on two new concepts for ground based dilution refrigerators is also ongoing. Finally developments on various key technologies such as the heat switches, the suspension or structural systems are also carried out. These developments are mainly funded by the European Space Agency (ESA) or by the Centre National d'Études Spatiales (CNES). In this paper we mostly give an overview of the developments carried out at SBT along with several examples of other relevant systems. We use space cryogenics as a thread. However these coolers or techniques can be used on ground, particularly on remote locations where liquid cryogen are unavailable and/or where maintenance must be limited to a strict minimum. In this case they can be simplified and take advantage of on ground resources, and their cost can be significantly reduced. For most of these systems the common feature is the absence of any moving parts or any friction, which guarantees a very good reliability and make them very good candidates for space borne instruments requiring cryogenic temperatures.

  5. Recent Advances and Applications in Cryogenic Propellant Densification Technology

    NASA Technical Reports Server (NTRS)

    Tomsik, Thomas M.

    2000-01-01

    This purpose of this paper is to review several historical cryogenic test programs that were conducted at the NASA Glenn Research Center (GRC), Cleveland, Ohio over the past fifty years. More recently these technology programs were intended to study new and improved denser forms of liquid hydrogen (LH2) and liquid oxygen (LO2) cryogenic rocket fuels. Of particular interest are subcooled cryogenic propellants. This is due to the fact that they have a significantly higher density (eg. triple-point hydrogen, slush etc.), a lower vapor pressure and improved cooling capacity over the normal boiling point cryogen. This paper, which is intended to be a historical technology overview, will trace the past and recent development and testing of small and large-scale propellant densification production systems. Densifier units in the current GRC fuels program, were designed and are capable of processing subcooled LH2 and L02 propellant at the X33 Reusable Launch Vehicle (RLV) scale. One final objective of this technical briefing is to discuss some of the potential benefits and application which propellant densification technology may offer the industrial cryogenics production and end-user community. Density enhancements to cryogenic propellants (LH2, LO2, CH4) in rocket propulsion and aerospace application have provided the opportunity to either increase performance of existing launch vehicles or to reduce the overall size, mass and cost of a new vehicle system.

  6. Theoretical analysis of performance enhancement in GeSn/SiGeSn light-emitting diode enabled by Si3N4 liner stressor technique.

    PubMed

    Zhang, Qingfang; Liu, Yan; Han, Genquan; Shao, Yao; Gao, Xi; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2016-12-01

    We comprehensively investigate the energy band diagrams, carrier distribution, spontaneous emission rate rsp, and the internal quantum efficiency ηIQE in the lattice-matched GeSn/SiGeSn double heterostructure light-emitting diode (LED) wrapped in a Si3N4 liner stressor. The large tensile strain introduced into the device by the expansion of the Si3N4 liner is characterized by numerical simulation. A lower Sn composition required for the indirect to direct bandgap transition and a higher ratio of the electron occupation probability in the Γ conduction valley are achieved in the tensile strained GeSn/SiGeSn LED in comparison with the relaxed device. Analytical calculation shows that the tensile strained LED wrapped in the Si3N4 liner stressor exhibits the improved rsp and ηIQE compared to the relaxed device. rsp and ηIQE also can be enhanced by increasing Sn composition, carrier injection density, and n-type doping concentration in the GeSn active layer.

  7. Ultrastable Cryogenic Microwave Oscillators

    NASA Astrophysics Data System (ADS)

    Mann, Anthony G.

    Ultrastable cryogenic microwave oscillators are secondary frequency standards in the microwave domain. The best of these oscillators have demonstrated a short term frequency stability in the range 10-14 to a few times 10-16. The main application for these oscillators is as flywheel oscillators for the next generation of passive atomic frequency standards, and as local oscillators in space telemetry ground stations to clean up the transmitter close in phase noise. Fractional frequency stabilities of passive atomic frequency standards are now approaching 3 x10^-14 /τ where τ is the measurement time, limited only by the number of atoms that are being interrogated. This requires an interrogation oscillator whose short-term stability is of the order of 10-14 or better, which cannot be provided by present-day quartz technology. Ultrastable cryogenic microwave oscillators are based on resonators which have very high electrical Q-factors. The resolution of the resonator's linewidth is typically limited by electronics noise to about 1ppm and hence Q-factors in excess of 108 are required. As these are only attained in superconducting cavities or sapphire resonators at low temperatures, use of liquid helium cooling is mandatory, which has so far restricted these oscillators to the research or metrology laboratory. Recently, there has been an effort to dispense with the need for liquid helium and make compact flywheel oscillators for the new generation of primary frequency standards. Work is under way to achieve this goal in space-borne and mobile liquid-nitrogen-cooled systems. The best cryogenic oscillators developed to date are the ``whispering gallery'' (WG) mode sapphire resonator-oscillators of NASA's Jet Propulsion Laboratory (JPL) and the University of Western Australia (UWA), as well as Stanford University's superconducting cavity stabilized oscillator (SCSO). All of these oscillators have demonstrated frequency

  8. Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout

    NASA Astrophysics Data System (ADS)

    England, Troy; Lilly, Michael; Curry, Matthew; Carr, Stephen; Carroll, Malcolm

    Fast, low-power quantum state readout is one of many challenges facing quantum information processing. Single electron transistors (SETs) are potentially fast, sensitive detectors for performing spin readout of electrons bound to Si:P donors. From a circuit perspective, however, their output impedance and nonlinear conductance are ill suited to drive the parasitic capacitance of coaxial conductors used in cryogenic environments, necessitating a cryogenic amplification stage. We will introduce two new amplifier topologies that provide excellent gain versus power tradeoffs using silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The AC HBT allows in-situ adjustment of power dissipation during an experiment and can provide gain in the millikelvin temperature regime while dissipating less than 500 nW. The AC Current Amplifier maximizes gain at nearly 800 A/A. We will also show results of using these amplifiers with SETs at 4 K. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000. Flexible Low-power SiGe HBT Amplifier Circuits for Fast Single-shot Spin Readout.

  9. Cryogenic cooler apparatus

    DOEpatents

    Wheatley, John C.; Paulson, Douglas N.; Allen, Paul C.

    1983-01-01

    A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. .sup.4 He, .sup.3 He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3-4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel.

  10. Cryogenic nuclear gyroscope

    SciTech Connect

    Gallop, J.C.; Potts, S.P.

    1980-09-30

    A cryogenic nuclear gyroscope is described that is comprised of a cylinder of niobium cooled within a helium cryostat so as to be superconducting and to provide a trapped, substantially homogeneous magnetic field, a helium-3 sample contained within a spherical pyrex cell having nuclei possessing a net magnetic moment, coils provided to polarize the sample to provide that net magnetic moment, and a SQUID magnetometer coupled to the sample by a pick-up coil of a transformer and frequency sensitive means coupled to the SQUID to detect changes in the precession of the nuclear moments of the sample caused by rotation of the gyroscope about an axis parallel to the direction of the homogeneous magnetic field. A superconducting lead shield isolates the helium-3 sample from external magnetic fields.

  11. Cryogenic Wind Tunnels.

    DTIC Science & Technology

    1980-07-01

    4 Ua 0 - mI - L - In 04 4 0 .e NA rA 0O r, 41 --t4..4 Z~, 4A e4 LANO wIU a~I. . 4 *0r I .- . . . .44 󈧰 6j.4. oo I~~~ 0 A I 1 I 4 L tr- A I N 𔃺 LA...sometimes appropriate for industrial aerodynamics. 1.00 LINE pr ATM Tr K LINE Pt. ATM Tt’ K .9 -1 3D .9_ _ _ P. 09 390 HELIUM IDEAL .94 HELIUM IDEA L 𔃿 .92...L8CRYOGENIC WIND TUNNELS. (U) UNCLASSIFIED AGARDLS111" 1111 18* 111122 1111 111 - 1I1111.25 IIQ14 111.6 MI (NO(OPY RP tHI1IN Illki AGAVEI.11 C i

  12. Cryogenic Cam Butterfly Valve

    NASA Technical Reports Server (NTRS)

    McCormack, Kenneth J. (Inventor)

    2016-01-01

    A cryogenic cam butterfly valve has a body that includes an axially extending fluid conduit formed there through. A disc lug is connected to a back side of a valve disc and has a circular bore that receives and is larger than a cam of a cam shaft. The valve disc is rotatable for a quarter turn within the body about a lug axis that is offset from the shaft axis. Actuating the cam shaft in the closing rotational direction first causes the camming side of the cam of the cam shaft to rotate the disc lug and the valve disc a quarter turn from the open position to the closed position. Further actuating causes the camming side of the cam shaft to translate the valve disc into sealed contact with the valve seat. Opening rotational direction of the cam shaft reverses these motions.

  13. Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Jones, David

    2011-01-01

    The CPS is an in-space cryogenic propulsive stage based largely on state of the practice design for launch vehicle upper stages. However, unlike conventional propulsive stages, it also contains power generation and thermal control systems to limit the loss of liquid hydrogen and oxygen due to boil-off during extended in-space storage. The CPS provides the necessary (Delta)V for rapid transfer of in-space elements to their destinations or staging points (i.e., E-M L1). The CPS is designed around a block upgrade strategy to provide maximum mission/architecture flexibility. Block 1 CPS: Short duration flight times (hours), passive cryo fluid management. Block 2 CPS: Long duration flight times (days/weeks/months), active and passive cryo fluid management.

  14. Cryogenic expansion machine

    DOEpatents

    Pallaver, Carl B.; Morgan, Michael W.

    1978-01-01

    A cryogenic expansion engine includes intake and exhaust poppet valves each controlled by a cam having adjustable dwell, the valve seats for the valves being threaded inserts in the valve block. Each cam includes a cam base and a ring-shaped cam insert disposed at an exterior corner of the cam base, the cam base and cam insert being generally circular but including an enlarged cam dwell, the circumferential configuration of the cam base and cam dwell being identical, the cam insert being rotatable with respect to the cam base. GI CONTRACTUAL ORIGIN OF THE INVENTION The invention described herein was made in the course of, or under, a contract with the UNITED STATES ENERGY RESEARCH AND DEVELOPMENT ADMINISTRATION.

  15. Cryogenic cooler apparatus

    DOEpatents

    Wheatley, J.C.; Paulson, D.N.; Allen, P.C.

    1983-01-04

    A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. [sup 4]He, [sup 3]He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3--4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel. 10 figs.

  16. GeOx/Reduced Graphene Oxide Composite as an Anode for Li-ion Batteries: Enhanced Capacity via Reversible Utilization of Li2O along with Improved Rate Performance

    SciTech Connect

    Lv, Dongping; Gordin, Mikhail; Yi, Ran; Xu, Terrence; Song, Jiangxuan; Jiang, Yingbing; Choi, Daiwon; Wang, Donghai

    2014-09-01

    A self-assembled GeOx/reduced graphene oxide (GeOx/RGO) composite, where GeOx nanoparticles were grown directly on reduced graphene oxide sheets, was synthesized via a facile one-step reduction approach and studied by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray spectroscopy, electron energy loss spectroscopy elemental mapping, and other techniques. Electrochemical evaluation indicates that incorporation of reduced graphene oxide enhances both the rate capability and reversible capacity of GeOx, with the latter being due to the RGO enabling reversible utilization of Li2O. The composite delivers a high reversible capacity of 1600 mAhg-1 at a current density of 100 mAg-1, and still maintains a capacity of 410 mAhg-1 at a high current density of 20 Ag-1. Owing to the flexible reduced graphene oxide sheets enwrapping the GeOx particles, the cycling stability of the composite was also improved significantly. To further demonstrate its feasibility in practical applications, the synthesized GeOx/RGO composite anode was successfully paired with a high voltage LiNi0.5Mn1.5O4 cathode to form a full cell, which showed good cycling and rate performance.

  17. Design and Operation of Cryogenic Distillation Research Column for Ultra-Low Background Experiments

    NASA Astrophysics Data System (ADS)

    Chiller, Christopher; Alanson Chiller, Angela; Jasinski, Benjamin; Snyder, Nathan; Mei, Dongming

    2013-04-01

    Motivated by isotopically enriched germanium (76Ge and 73Ge) for monocrystalline crystal growth for neutrinoless double-beta decay and dark matter experiments, a cryogenic distillation research column was developed. Without market availability of distillation columns in the temperature range of interest with capabilities necessary for our purposes, we designed, fabricated, tested, refined and operated a two-meter research column for purifying and separating gases in the temperature range from 100-200K. Due to interest in defining stratification, purity and throughput optimization, capillary lines were integrated at four equidistant points along the length of the column such that real-time residual gas analysis could guide the investigation. Interior gas column temperatures were monitored and controlled within 0.1oK accuracy at the top and bottom. Pressures were monitored at the top of the column to four significant figures. Subsequent impurities were measured at partial pressures below 2E-8torr. We report the performance of the column in this paper.

  18. Cryogenic Insulation Standard Data and Methodologies Project

    NASA Technical Reports Server (NTRS)

    Summerfield, Burton; Thompson, Karen; Zeitlin, Nancy; Mullenix, Pamela; Fesmire, James; Swanger, Adam

    2015-01-01

    Extending some recent developments in the area of technical consensus standards for cryogenic thermal insulation systems, a preliminary Inter-Laboratory Study of foam insulation materials was performed by NASA Kennedy Space Center and LeTourneau University. The initial focus was ambient pressure cryogenic boil off testing using the Cryostat-400 flat-plate instrument. Completion of a test facility at LETU has enabled direct, comparative testing, using identical cryostat instruments and methods, and the production of standard thermal data sets for a number of materials under sub-ambient conditions. The two sets of measurements were analyzed and indicate there is reasonable agreement between the two laboratories. Based on cryogenic boiloff calorimetry, new equipment and methods for testing thermal insulation systems have been successfully developed. These boiloff instruments (or cryostats) include both flat plate and cylindrical models and are applicable to a wide range of different materials under a wide range of test conditions. Test measurements are generally made at large temperature difference (boundary temperatures of 293 K and 78 K are typical) and include the full vacuum pressure range. Results are generally reported in effective thermal conductivity (ke) and mean heat flux (q) through the insulation system. The new cryostat instruments provide an effective and reliable way to characterize the thermal performance of materials under subambient conditions. Proven in through thousands of tests of hundreds of material systems, they have supported a wide range of aerospace, industry, and research projects. Boiloff testing technology is not just for cryogenic testing but is a cost effective, field-representative methodology to test any material or system for applications at sub-ambient temperatures. This technology, when adequately coupled with a technical standards basis, can provide a cost-effective, field-representative methodology to test any material or system

  19. Cryogenic Systems and Superconductive Power

    DTIC Science & Technology

    subsystem suitable for providing reliable long-lived cryogenic refrigeration for a superconductive ship propulsion system; and, Provide a sound...technical basis for subsequent applications of superconductive power in the area of ship propulsion .

  20. Cryogenic Systems and Superconductive Power

    DTIC Science & Technology

    The report defines, investigates, and experimentally evaluates the key elements of a representative crogenic turborefrigerator subsystem suitable for providing reliable long-lived cryogenic refrigeration for a superconductive ship propulsion system.

  1. Developing NDE Techniques for Large Cryogenic Tanks

    NASA Technical Reports Server (NTRS)

    Parker, Don; Starr, Stan; Arens, Ellen

    2011-01-01

    The Shuttle Program requires very large cryogenic ground storage tanks in which to store liquid oxygen and hydrogen. The existing Pads A and B Launch Complex-39 tanks, which will be passed onto future launch programs, are 45 years old and have received minimal refurbishment and only external inspections over the years. The majority of the structure is inaccessible without a full system drain of cryogenic liquid and granular insulation in the annular region. It was previously thought that there was a limit to the number of temperature cycles that the tanks could handle due to possible insulation compaction before undergoing a costly and time consuming complete overhaul; therefore the tanks were not drained and performance issues with these tanks, specifically the Pad B liquid hydrogen tank, were accepted. There is a needind an opportunity, as the Shuttle program ends and work to upgrade the launch pads progresses, to develop innovative non-destructive evaluation (NDE) techniques to analyze the current tanks. Techniques are desired that can aid in determining the extent of refurbishment required to keep the tanks in service for another 20+ years. A nondestructive technique would also be a significant aid in acceptance testing of new and refurbished tanks, saving significant time and money, if corrective actions can be taken before cryogen is introduced to the systems.

  2. High-aperture cryogenic light microscopy.

    PubMed

    Le Gros, M A; McDermott, G; Uchida, M; Knoechel, C G; Larabell, C A

    2009-07-01

    We report here the development of instruments and protocols for carrying out high numerical aperture immersion light microscopy on cryogenic specimens. Imaging by this modality greatly increases the lifetimes of fluorescence probes, including those commonly used for protein localization studies, while retaining the ability to image the specimen with high fidelity and spatial resolution. The novel use of a cryogenic immersion fluid also minimizes the refractive index mismatch between the sample and lens, leading to a more efficient coupling of the light from the sample to the image forming system. This enhancement is applicable to both fluorescence and transmitted light microscopy techniques. The design concepts used for the cryogenic microscope can be applied to virtually any existing light-based microscopy technique. This prospect is particularly exciting in the context of 'super-resolution' techniques, where enhanced fluorescence lifetime probes are especially useful. Thus, using this new modality it is now possible to observe dynamic events in a live cell, and then rapidly vitrify the specimen at a specific time point prior to carrying out high-resolution imaging. The techniques described can be used in conjunction with other imaging modalities in correlated studies. We have also developed instrumentation to perform cryo-light imaging together with soft X-ray tomography on the same cryo-fixed specimen as a means of carrying out high content, quantifiable correlated imaging analyses. These methods are equally applicable to correlated light and electron microscopy of frozen biological objects.

  3. A Rapid Turnaround Cryogenic Detector Characterization System

    NASA Technical Reports Server (NTRS)

    Benford, Dominic j.; Dipirro, Michael J.; Forgione, Joshua B.; Jackson, Clifton E.; Jackson, Michael L.; Kogut, Al; Moseley, S. Harvey; Shirron, Peter J.

    2004-01-01

    Upcoming major NASA missions such as the Einstein Inflation Probe and the Single Aperture Far-Infrared Observatory require arrays of detectors with thousands of elements, operating at temperatures near l00 mK and sensitive to wavelengths from approx. 100 microns to approx. 3 mm. Such detectors represent a substantial enabling technology for these missions, and must be demonstrated soon in order for them to proceed. In order to make rapid progress on detector development, the cryogenic testing cycle must be made convenient and quick. We have developed a cryogenic detector characterization system capable of testing superconducting detector arrays in formats up to 8 x 32, read out by SQUID multiplexers. The system relies on the cooling of a two-stage adiabatic demagnetization refrigerator immersed in a liquid helium bath. This approach permits a detector to be cooled from 300K to 50 mK in about 4 hours, so that a test cycle begun in the morning will be over by the end of the day. Tine system is modular, with two identical immersible units, so that while one unit is cooling, the second can be reconfigured for the next battery of tests. We describe the design, construction, and performance of this cryogenic detector testing facility.

  4. Thermoelectric efficiency of (1 - x)(GeTe) x(Bi2Se0.2Te2.8) and implementation into highly performing thermoelectric power generators.

    PubMed

    Koenig, J; Winkler, M; Dankwort, T; Hansen, A-L; Pernau, H-F; Duppel, V; Jaegle, M; Bartholomé, K; Kienle, L; Bensch, W

    2015-02-14

    Here we report for the first time on a complete simulation assisted "material to module" development of a high performance thermoelectric generator (TEG) based on the combination of a phase change material and established thermoelectrics yielding the compositions (1 - x)(GeTe) x(Bi(2)Se(0.2)Te(2.8)). For the generator design our approach for benchmarking thermoelectric materials is demonstrated which is not restricted to the determination of the intrinsically imprecise ZT value but includes the implementation of the material into a TEG. This approach is enabling a much more reliable benchmarking of thermoelectric materials for TEG application. Furthermore we analyzed the microstructure and performance close to in-operandi conditions for two different compositions in order to demonstrate the sensitivity of the material against processing and thermal cycling. For x = 0.038 the microstructure of the as-prepared material remains unchanged, consequently, excellent and stable thermoelectric performance as prerequisites for TEG production was obtained. For x = 0.063 we observed strain phenomena for the pristine state which are released by the formation of planar defects after thermal cycling. Consequently the thermoelectric performance degrades significantly. These findings highlight a complication for deriving the correlation of microstructure and properties of thermoelectric materials in general.

  5. The RHIC cryogenic control system

    SciTech Connect

    Farah, Y.; Sondericker, J.

    1993-08-01

    A cryogenic process control system for the RHIC Project is discussed. It is independent of the main RHIC Control System, consisting of an upgrade of the existing 24.8 Kw helium refrigerator control section with the addition of a ring control section that regulates and monitors all cryogenic signals in the RHIC tunnel. The system is fully automated, which can run without the continuous presence of operators.

  6. Cryogenic foam insulation: Abstracted publications

    NASA Technical Reports Server (NTRS)

    Williamson, F. R.

    1977-01-01

    A group of documents were chosen and abstracted which contain information on the properties of foam materials and on the use of foams as thermal insulation at cryogenic temperatures. The properties include thermal properties, mechanical properties, and compatibility properties with oxygen and other cryogenic fluids. Uses of foams include applications as thermal insulation for spacecraft propellant tanks, and for liquefied natural gas storage tanks and pipelines.

  7. Cryogenic High Pressure Sensor Module

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor); Shams, Qamar A. (Inventor); Powers, William T. (Inventor)

    1999-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  8. Cryogenic, Absolute, High Pressure Sensor

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor); Shams. Qamar A. (Inventor); Powers, William T. (Inventor)

    2001-01-01

    A pressure sensor is provided for cryogenic, high pressure applications. A highly doped silicon piezoresistive pressure sensor is bonded to a silicon substrate in an absolute pressure sensing configuration. The absolute pressure sensor is bonded to an aluminum nitride substrate. Aluminum nitride has appropriate coefficient of thermal expansion for use with highly doped silicon at cryogenic temperatures. A group of sensors, either two sensors on two substrates or four sensors on a single substrate are packaged in a pressure vessel.

  9. Thermal management of cryogenic coolers used in military infrared sensors

    SciTech Connect

    Grimmett, J.D.; Rawlings, R.M.

    1996-12-31

    High performance infrared (IR) sensors are based on IR detectors that must be cooled to cryogenic temperatures to achieve the desired performance. The current IR sensors being developed utilize compact, linear drive cryocoolers based on the Stirling cycle to achieve the cryogenic temperatures. The integration of these coolers into the IR systems present a number of complex and unique challenges. One of the most significant affecting the reliability and performance of the system, is the thermal management of the cooler. Developing an effective heatsink design that maximizes cooling capacity and lifetime while meeting system requirements is a top priority. This paper discusses the thermal management issues of cryogenic coolers and the system requirements that influence the heatsink design. A thermal model and validation testing of the cooler is presented to show analytical capabilities for evaluating heatsink designs. The integration of the model and heatsink design into an IR system is demonstrated by comparing analytical results and empirical data.

  10. Uniaxially stressed Ge:Ga and Ge:Be

    SciTech Connect

    Dubon, O.D. Jr.

    1992-12-01

    The application of a large uniaxial stress to p-type Ge single crystals changes the character of both the valence band and the energy levels associated with the acceptors. Changes include the splitting of the fourfold degeneracy of the valence band top and the reduction of the ionization energy of shallow acceptors. In order to study the effect of uniaxial stress on transport properties of photoexcited holes, a variable temperature photo-Hall effect system was built in which stressed Ge:Ga and Ge:Be could be characterized. Results indicate that stress increases the lifetime and Hall mobility of photoexcited holes. These observations may help further the understanding of fundamental physical processes that affect the performance of stressed Ge photoconductors including the capture of holes by shallow acceptors.

  11. Latest developments in cryogenic safety

    NASA Technical Reports Server (NTRS)

    Webster, T. J.

    1983-01-01

    The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual hazardous situations. An awareness of the physical properties of the cryogenic fluids being dealt with is important in directing attention to hazardous situations which may arise. Because of this, the more important properties of the cryogenic fluids are given, such as molecular weight, boiling point and freezing point. From these properties, hazardous situations can be deduced. There are hidden dangers that are not always easy to spot. Some of the unexpected hazards, most of which have led to deaths, are: asphyxiation (anoxia), frost bites and hypothermia, explosions, and combustion. The aim of this publication is to help bring about increased safety in the production and use of cryogenic products through a deeper appreciation of the scientific, technological and administrative steps which must be made if accidents, some fatal, are to be voided in the future.

  12. Latest developments in cryogenic safety

    NASA Astrophysics Data System (ADS)

    Webster, T. J.

    1983-03-01

    The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual hazardous situations. An awareness of the physical properties of the cryogenic fluids being dealt with is important in directing attention to hazardous situations which may arise. Because of this, the more important properties of the cryogenic fluids are given, such as molecular weight, boiling point and freezing point. From these properties, hazardous situations can be deduced. There are hidden dangers that are not always easy to spot. Some of the unexpected hazards, most of which have led to deaths, are: asphyxiation (anoxia), frost bites and hypothermia, explosions, and combustion. The aim of this publication is to help bring about increased safety in the production and use of cryogenic products through a deeper appreciation of the scientific, technological and administrative steps which must be made if accidents, some fatal, are to be voided in the future.

  13. Cryogenic Vacuum Insulation for Vessels and Piping

    NASA Technical Reports Server (NTRS)

    Kogan, A.; Fesmire, J.; Johnson, W.; Minnick, J.

    2010-01-01

    Cryogenic vacuum insulation systems, with proper materials selection and execution, can offer the highest levels of thermal performance. Three areas of consideration are vital to achieve the optimum result: materials, representative test conditions, and engineering approach for the particular application. Deficiency in one of these three areas can prevent optimum performance and lead to severe inefficiency. Materials of interest include micro-fiberglass, multilayer insulation, and composite arrangements. Cylindrical liquid nitrogen boil-off calorimetry methods were used. The need for standard thermal conductivity data is addressed through baseline testing. Engineering analysis and design factors such as layer thickness, density, and practicality are also considered.

  14. Ferromagnetic germanide in Ge nanowire transistors for spintronics application.

    PubMed

    Tang, Jianshi; Wang, Chiu-Yen; Hung, Min-Hsiu; Jiang, Xiaowei; Chang, Li-Te; He, Liang; Liu, Pei-Hsuan; Yang, Hong-Jie; Tuan, Hsing-Yu; Chen, Lih-Juann; Wang, Kang L

    2012-06-26

    To explore spintronics applications for Ge nanowire heterostructures formed by thermal annealing, it is critical to develop a ferromagnetic germanide with high Curie temperature and take advantage of the high-quality interface between Ge and the formed ferromagnetic germanide. In this work, we report, for the first time, the formation and characterization of Mn(5)Ge(3)/Ge/Mn(5)Ge(3) nanowire transistors, in which the room-temperature ferromagnetic germanide was found through the solid-state reaction between a single-crystalline Ge nanowire and Mn contact pads upon thermal annealing. The atomically clean interface between Mn(5)Ge(3) and Ge with a relatively small lattice mismatch of 10.6% indicates that Mn(5)Ge(3) is a high-quality ferromagnetic contact to Ge. Temperature-dependent I-V measurements on the Mn(5)Ge(3)/Ge/Mn(5)Ge(3) nanowire heterostructure reveal a Schottky barrier height of 0.25 eV for the Mn(5)Ge(3) contact to p-type Ge. The Ge nanowire field-effect transistors built on the Mn(5)Ge(3)/Ge/Mn(5)Ge(3) heterostructure exhibit a high-performance p-type behavior with a current on/off ratio close to 10(5), and a hole mobility of 150-200 cm(2)/(V s). Temperature-dependent resistance of a fully germanided Mn(5)Ge(3) nanowire shows a clear transition behavior near the Curie temperature of Mn(5)Ge(3) at about 300 K. Our findings of the high-quality room-temperature ferromagnetic Mn(5)Ge(3) contact represent a promising step toward electrical spin injection into Ge nanowires and thus the realization of high-efficiency spintronic devices for room-temperature applications.

  15. Baseline Configuration of the Cryogenic System for the International Linear Collider

    SciTech Connect

    Casas-Cubillos, J.; Claudet, S.; Parma, V.; Riddone, G.; Serio, L.; Tavian, L.; Vullierme, B.; van Weelderen, R.; Chorowski, M.; Ganni, R.; Rode, C.; Klebaner, A.; Peterson, T.; Theilacker, J.; Rousset, B.; Weisend, J.; /SLAC

    2007-06-18

    The paper discusses the main constraints and boundary conditions and describes the baseline configuration of the International Linear Collider (ILC) cryogenic system. The cryogenic layout, architecture and the cooling principle are presented. The paper addresses a plan for study and development required to demonstrate and improve the performance, to reduce cost and to attain the desired reliability.

  16. Proceedings of the 26th International Cryogenic Engineering Conference – International Cryogenic Material Conference 2016

    NASA Astrophysics Data System (ADS)

    Datta, T. S.; Sharma, R. G.; Kar, S.

    2017-02-01

    Session There were 6 plenary talks delivered by the eminent scientist/ technologists. The topics on which these talks were delivered were Cryogenics for Indian Space Programme, The Cold Chain, Super-fluid Cooling Technology, Review on Superconducting Materials in China, Review on Cryogenics and Superconductivity for present day MRI and finally the Mendelssohn Award lecture on the 50 years of Cryogenics and Superconductivity for High Energy Physics. Other than the plenary talks, there were 102 oral presentations covered in 18 technical sessions, out of which 21 were Invited Talks. Each session was dedicated to a specific topic like Large Scale Cryogenics, Cryogenics for Accelerators, Fusion and Space, Cryocoolers, Heat Transfer, Cryogenic Instrumentation, Superconducting Materials, Superconducting Magnets & Cavities, Power Applications, LNG & Safety etc. In addition to oral presentations there were three poster sessions spread over three days and a total of 250 posters were displayed. 4. Award Session There was a dedicated session on Award Ceremony. Dr Haishan Cao, post doctoral researcher at the University of Twente, The Netherlands received the 2016 Klipping Award for his work on Micro-machined Joule-Thomson coolers. The ICMC Cryogenic Material Awardee for Excellence (2016) was Prof. Kazumasa Iida, Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University. Japan. The paper published in ” Cryogenics 72 (2015), p 111-121 by J. Bartlett, G. Hardy, and I.D. Hepburn, titled “Performance of a fast response miniature Adiabatic Demagnetization Refrigerator using a single crystal tungsten magneto resistive heat switch” was selected for the best paper award. The prestigious 2016 Mendelssohn Award was given to Dr. Philippe Lebrun of CERN, Geneva, Switzerland for his life-long contribution to Cryogenics and Superconductivity for accelerator programme. Each awardees was also presented with a complimentary book from Springer Nature through

  17. The Impact of the GE Foundation "Developing Futures"™ in Education Program on Mathematics Performance Trends in Four Districts. Research Report # RR-74

    ERIC Educational Resources Information Center

    Sirinides, Philip; Supovitz, Jonathan; Tognatta, Namrata; May, Henry

    2013-01-01

    Beginning in 2005, the GE Foundation initiated a commitment of expertise and financial resources to a set of urban school districts to improve public education and enhance student achievement in mathematics and science. This report analyzes the impacts of the GE Foundation commitment to the partner districts by examining trends in student…

  18. Development of a cryogenic rotating heat pipe joint

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The performance of two critical technology components required for a continuously rotatable heat pipe: (1) a low-leakage rotatable coupling for the heat pipe pressure vessel, and (2) a rotatable internal wick, is reported. Performance and leakage requirements were established based on 12 months operation of a cryogenic rotatable heat pipe on a satellite in earth orbit.

  19. Thermoelectric Performance of Multiple-Doped Co4Sb12- x- y- z Ge x Te y S z Skutterudite Compounds

    NASA Astrophysics Data System (ADS)

    Duan, Bo; Zhai, Pengcheng; Liu, Lisheng; Chen, Gang; Li, Peng; Zhang, Qingjie

    2013-07-01

    CoSb3 skutterudites multiply doped with Ge, Te, and S were synthesized by solid-state reaction and spark plasma sintering. x-Ray diffraction studies revealed that Ge, Te, and S entered the lattice of the CoSb3 compounds, and while Te increased the lattice volume, Ge and S decreased it. Compared with the undoped and single-doped CoSb3 compounds, the thermal conductivity and lattice thermal conductivity are significantly suppressed due to greatly increased point defect scattering. It is found that S is more effective for decreasing the lattice thermal conductivity than Te and Ge. The highest thermoelectric figure of merit, ZT, exceeds 1.1 for the Co4Sb11.25Ge0.05Te0.63S0.07 compound at 800 K.

  20. Radiation requirements and testing of cryogenic thermometers for the ILC

    SciTech Connect

    Barnett, T.; Filippov, Yu.P.; Mokhov, N.V.; Nakao, N.; Klebaner, A.L.; Korenev, S.A.; Theilacker, J.C. /; Trenikhina, J.; Vaziri, K.; /Fermilab

    2007-07-01

    Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox{reg_sign} and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

  1. Cryogenic Moisture Uptake in Foam Insulation for Space Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.; ScholtensCoffman, Brekke E.; Sass, Jared P.; Williams, Martha K.; Smith, Trent M.; Meneghelli, Barrry J.

    2008-01-01

    Rigid polyurethane foams and rigid polyisocyanurate foams (spray-on foam insulation), like those flown on Shuttle, Delta IV, and will be flown on Ares-I and Ares-V, can gain an extraordinary amount of water when under cryogenic conditions for several hours. These foams, when exposed for eight hours to launch pad environments on one side and cryogenic temperature on the other, increase their weight from 35 to 80 percent depending on the duration of weathering or aging. This effect translates into several thousand pounds of additional weight for space vehicles at lift-off. A new cryogenic moisture uptake apparatus was designed to determine the amount of water/ice taken into the specimen under actual-use propellant loading conditions. This experimental study included the measurement of the amount of moisture uptake within different foam materials. Results of testing using both aged specimens and weathered specimens are presented. To better understand cryogenic foam insulation performance, cryogenic moisture testing is shown to be essential. The implications for future launch vehicle thermal protection system design and flight performance are discussed.

  2. Heterogeneous integration of SiGe/Ge and III-V for Si photonics

    NASA Astrophysics Data System (ADS)

    Takenaka, Mitsuru; Kim, Younghyun; Han, Jaehoon; Kang, Jian; Ikku, Yuki; Cheng, Yongpeng; Park, Jinkwon; Takagi, Shinichi

    2016-05-01

    The heterogeneous integration of SiGe/Ge and III-V semiconductors gives us an opportunity to enhance functionalities of Si photonics platform through their superior material properties which lack in Si. In this paper we discuss what SiGe/Ge and III-V can bring to Si photonics. We have predicted that the light effective hole mass in strained SiGe results in the enhanced the free-carrier effects such as the plasma dispersion effect and free-carrier absorption. We observed significantly larger free-carrier absorption in the SiGe optical modulator than in the control Si device. By fabricating asymmetric Mach-Zehnder interferometer (MZI) SiGe optical modulators, the enhancement of the plasma dispersion effect in strained SiGe has been successfully demonstrated. Mid-infrared integrated photonics based on Ge waveguides on Si have also been investigated. Since Ge is transparent to the entire mid-infrared range, Ge photonic integrated circuits on the Ge-on-Insulator (GeOI) wafer are quite attractive. We have successfully fabricated the GeOI wafer with 2-μm-thick buried oxide (BOX) layer by wafer bonding. The passive waveguide components based on Ge strip waveguides have been demonstrated on the GeOI. We have also demonstrated carrier-injection Ge variable optical attenuators. We have proposed and investigate the III-V CMOS photonics platform by using the III-V on Insulator (IIIV- OI) on a Si wafer. The strong optical confinement in the III-V-OI enables us to achieve high-performance photonic devices. We have successfully demonstrated InGaAsP MZI optical switch with the low on-state crosstalk on the III-V-OI. Ultra-low dark current waveguide InGaAs PDs integrated with an InP grating coupler are also achieved.

  3. Deformation microstructure and positive temperature dependence of flow stress in Ni{sub 3}Ge

    SciTech Connect

    Solov’eva, Yulia Starenchenko, Vladimir Starenchenko, Svetlana Solov’ev, Artem

    2016-01-15

    Single crystalline specimens of Ni{sub 3}Ge were compressed along [0 0 1] at different temperatures. Temperature dependence of the critical resolved shear stress (τ{sub 0}(T)) has been obtained. Detailed measurements at cryogen temperatures (4.2-77 K temperature interval) showed that the increase of the yield stress with temperature starts at liquid helium temperature. The values of the apparent activation volume (V*) have been obtained as a result of stress relaxation tests repeated along the stress-strain curve at different stress levels at seven temperatures (77, 293, 373, 473, 573, 673, 773 K). Transmission electron microscopy (TEM) methods were used to analyze the evolution of dislocation structure with temperature and strain. The measurements of the straight dislocations fraction determined as δ = ρ{sub sd} / ρ, (ρ{sub sd} is the straight dislocation density, ρ is a total dislocation density) have been performed. The experimental data obtained in different tests in Ni{sub 3}Ge confirm two-stage nature of the positive temperature dependence of the flow stress of alloys with the L1{sub 2} structure. The model of thermal strengthening considering two different types of mechanisms, first acting at low temperatures and second at high has been proposed. Using this model the temperature dependence of the critical resolved shear stress has been approximated and the activation parameters of thermal strengthening of Ni{sub 3}Ge have been obtained.

  4. Cryogenic Electric Motor Tested

    NASA Technical Reports Server (NTRS)

    Brown, Gerald V.

    2004-01-01

    Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

  5. Process modules for GeSn nanoelectronics with high Sn-contents

    NASA Astrophysics Data System (ADS)

    Schulte-Braucks, C.; Glass, S.; Hofmann, E.; Stange, D.; von den Driesch, N.; Hartmann, J. M.; Ikonic, Z.; Zhao, Q. T.; Buca, D.; Mantl, S.

    2017-02-01

    This paper systematically studies GeSn n-FETs, from individual process modules to a complete device. High-k gate stacks and NiGeSn metallic contacts for source and drain are characterized in independent experiments. To study both direct and indirect bandgap semiconductors, a range of 0-14.5 at.% Sn-content GeSn alloys are investigated. Special emphasis is placed on capacitance-voltage (C-V) characteristics and Schottky-barrier optimization. GeSn n-FET devices are presented including temperature dependent I-V characteristics. Finally, as an important step towards implementing GeSn in tunnel-FETs, negative differential resistance in Ge0.87Sn0.13 tunnel-diodes is demonstrated at cryogenic temperatures. The present work provides a base for further optimization of GeSn FETs and novel tunnel FET devices.

  6. Electrical performance of phase change memory cells with Ge{sub 3}Sb{sub 2}Te{sub 6} deposited by molecular beam epitaxy

    SciTech Connect

    Boschker, Jos E.; Riechert, Henning; Calarco, Raffaella; Boniardi, Mattia; Redaelli, Andrea

    2015-01-12

    Here, we report on the electrical characterization of phase change memory cells containing a Ge{sub 3}Sb{sub 2}Te{sub 6} (GST) alloy grown in its crystalline form by Molecular Beam Epitaxy (MBE). It is found that the high temperature growth on the amorphous substrate results in a polycrystalline film exhibiting a rough surface with a grain size of approximately 80–150 nm. A detailed electrical characterization has been performed, including I-V characteristic curves, programming curves, set operation performance, crystallization activation at low temperature, and resistance drift, in order to determine the material related parameters. The results indicate very good alignment of the electrical parameters with the current state-of-the-art GST, deposited by physical vapor deposition. Such alignment enables a possible employment of the MBE deposition technique for chalcogenide materials in the phase change memory technology, thus leading to future studies of as-deposited crystalline chalcogenides as integrated in electrical vehicles.

  7. Development of cryogenic rupture discs for the space borne CRISTA project

    NASA Astrophysics Data System (ADS)

    Trant, R.; Neusser, C.; Offermann, D.; Kesting, F.

    Space cryostats require safety components to protect the cryogenic system against overpressure. The CRISTA cryostat (Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere), which contains 725 1 supercritical helium, will have a three stage safety system. A cryogenic rupture disc mounted directly on the helium tank will be the ultimate safety component. For qualifying cryogenic rupture discs a low temperature test facility was developed. The batch qualification of the cryogenic rupture disc, which is of the reserve buckling type, shows a standard deviation comparable with that at ambient temperature. The design of the rupture disc as well as test program and test results of the successfully performed qualification are described. Furthermore, design and performance of the low temperature test facility are treated.

  8. Evolvable Cryogenics (ECRYO) Pressure Transducer Calibration Test

    NASA Technical Reports Server (NTRS)

    Diaz, Carlos E., Jr.

    2015-01-01

    This paper provides a summary of the findings of recent activities conducted by Marshall Space Flight Center's (MSFC) In-Space Propulsion Branch and MSFC's Metrology and Calibration Lab to assess the performance of current "state of the art" pressure transducers for use in long duration storage and transfer of cryogenic propellants. A brief historical narrative in this paper describes the Evolvable Cryogenics program and the relevance of these activities to the program. This paper also provides a review of three separate test activities performed throughout this effort, including: (1) the calibration of several pressure transducer designs in a liquid nitrogen cryogenic environmental chamber, (2) the calibration of a pressure transducer in a liquid helium Dewar, and (3) the calibration of several pressure transducers at temperatures ranging from 20 to 70 degrees Kelvin (K) using a "cryostat" environmental chamber. These three separate test activities allowed for study of the sensors along a temperature range from 4 to 300 K. The combined data shows that both the slope and intercept of the sensor's calibration curve vary as a function of temperature. This homogeneous function is contrary to the linearly decreasing relationship assumed at the start of this investigation. Consequently, the data demonstrates the need for lookup tables to change the slope and intercept used by any data acquisition system. This ultimately would allow for more accurate pressure measurements at the desired temperature range. This paper concludes with a review of a request for information (RFI) survey conducted amongst different suppliers to determine the availability of current "state of the art" flight-qualified pressure transducers. The survey identifies requirements that are most difficult for the suppliers to meet, most notably the capability to validate the sensor's performance at temperatures below 70 K.

  9. Latest developments in cryogenic safety

    SciTech Connect

    Webster, T.J.

    1983-03-01

    The Cryogenic Safety Manual, sponsored by the British Cryogenics Council, was published over 10 years ago. A new updated version is now available. Some general aspects of cryogenic safety are highlighted, and attention is drawn to some of the more unusual hazardous situations. An awareness of the physical properties of the cryogenic fluids being dealt with is important in directing attention to hazardous situations which may arise. Because of this, the more important properties of the cryogenic fluids are given, such as molecular weight, boiling point and freezing point. From these properties, hazardous situations can be deduced. There are hidden dangers that are not always easy to spot. Some of the unexpected hazards, most of which have led to deaths, are: asphyxiation (anoxia), frost bites and hypothermia, explosions, and combustion. The aim of this publication is to help bring about increased safety in the production and use of crygenic products through a deeper appreciation of the scientific, technological and administrative steps which must be made if accidents, some fatal, are to be voided in the future.

  10. Thermodynamic Analyses of the LCLS-II Cryogenic Distribution System

    SciTech Connect

    Dalesandro, Andrew; Kaluzny, Joshua; Klebaner, Arkadiy

    2016-12-29

    The Linac Coherent Light Source (LCLS) at Stanford Linear Accelerator Center (SLAC) is in the process of being upgraded to a superconducting radio frequency (SRF) accelerator and renamed LCLS-II. This upgrade requires thirty-five 1.3 GHz SRF cryomodules (CM) and two 3.9 GHz CM. A cryogenic distribution system (CDS) is in development by Fermi National Accelerator Laboratory to interconnect the CM Linac with the cryogenic plant (CP). The CDS design utilizes cryogenic helium to support the CM operations with a high temperature thermal shield around 55 K, a low temperature thermal intercepts around 5 K, and a SRF cavity liquid helium supply and sub-atmospheric vapor return both around 2 K. Additionally the design must accommodate a Linac consisting of two parallel cryogenic strings, supported by two independent CP utilizing CDS components such as distribution boxes, transfer lines, feed caps and endcaps. In this paper, we describe the overall layout of the cryogenic distribution system and the major thermodynamic factors which influence the CDS design including heat loads, pressure drops, temperature profiles, and pressure relieving requirements. In addition the paper describes how the models are created to perform the analyses.

  11. Towards the cryogenic sliding mechanism for MOONS-ESO

    NASA Astrophysics Data System (ADS)

    Tozzi, A.; Carbonaro, L.; Oliva, T.; Iuzzolino, M.; Strachan, J.; Rees, P.

    2016-08-01

    The Multi-Object Optical and Near-Infrared Spectrograph (MOONS) shall be installed at one of the Very Large Telescopes (VLT) at the European Southern Observatory (ESO) in Paranal Chile. The instrument is being designed and built by an international consortium on behalf of ESO. The design is based on a three arms configuration, RI, YJ and H band, where RI and H have two possible resolutions. To achieve this goal it will be necessary to implement a sliding mechanism changing the dispersers, the filters and the cross dispersion prisms. This article describes the cryogenic exchanger mechanism that is under realization and the preliminary mechanical and optical tests that we have done at the cryogenic facility of Arcetri observatory of Florence. Parts of these test are based on interferometric measurements of the optics to study the behaviour of the mechanical supporting structure, and part are based on the cryogenic sliding system that will be used to move approximately 200 Kg of mass for 350 mm of travel range. The cryogenic sliding system, rails, screws, motors, is based on commercial components as the position measurement device that is based on commercial potentiometers. The results of the tests and performances at cryogenic temperature are reported in this paper.

  12. Computing Thermal Effects of Cavitation in Cryogenic Liquids

    NASA Technical Reports Server (NTRS)

    Hosangadi, Ashvin; Ahuja, Vineet; Dash, Sanford M.

    2005-01-01

    A computer program implements a numerical model of thermal effects of cavitation in cryogenic fluids. The model and program were developed for use in designing and predicting the performances of turbopumps for cryogenic fluids. Prior numerical models used for this purpose do not account for either the variability of properties of cryogenic fluids or the thermal effects (especially, evaporative cooling) involved in cavitation. It is important to account for both because in a cryogenic fluid, the thermal effects of cavitation are substantial, and the cavitation characteristics are altered by coupling between the variable fluid properties and the phase changes involved in cavitation. The present model accounts for both thermal effects and variability of properties by incorporating a generalized representation of the properties of cryogenic fluids into a generalized compressible-fluid formulation for a cavitating pump. The model has been extensively validated for liquid nitrogen and liquid hydrogen. Using the available data on the properties of these fluids, the model has been shown to predict accurate temperature-depression values.

  13. Thermodynamic Analyses of the LCLS-II Cryogenic Distribution System

    DOE PAGES

    Dalesandro, Andrew; Kaluzny, Joshua; Klebaner, Arkadiy

    2016-12-29

    The Linac Coherent Light Source (LCLS) at Stanford Linear Accelerator Center (SLAC) is in the process of being upgraded to a superconducting radio frequency (SRF) accelerator and renamed LCLS-II. This upgrade requires thirty-five 1.3 GHz SRF cryomodules (CM) and two 3.9 GHz CM. A cryogenic distribution system (CDS) is in development by Fermi National Accelerator Laboratory to interconnect the CM Linac with the cryogenic plant (CP). The CDS design utilizes cryogenic helium to support the CM operations with a high temperature thermal shield around 55 K, a low temperature thermal intercepts around 5 K, and a SRF cavity liquid heliummore » supply and sub-atmospheric vapor return both around 2 K. Additionally the design must accommodate a Linac consisting of two parallel cryogenic strings, supported by two independent CP utilizing CDS components such as distribution boxes, transfer lines, feed caps and endcaps. In this paper, we describe the overall layout of the cryogenic distribution system and the major thermodynamic factors which influence the CDS design including heat loads, pressure drops, temperature profiles, and pressure relieving requirements. In addition the paper describes how the models are created to perform the analyses.« less

  14. Cryogenic switched MOSFET characterization

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Both p channel and n channel enhancement mode MOSFETs can be readily switched on and off at temperatures as low as 2.8 K so that switch sampled readout of a VLWIR Ge:Ga focal plane is electronically possible. Noise levels as low as 100 rms electrons per sample (independent of sample rate) can be achieved using existing p channel MOSFETs, at overall rates up to 30,000 samples/second per multiplexed channel (e.g., 32 detectors at a rate of almost 1,000 frames/second). Run of the mill devices, including very low power dissipation n channel FETs would still permit noise levels of the order of 500 electrons/sample.

  15. Latest developments in cryogenic safety

    NASA Astrophysics Data System (ADS)

    Webster, T.

    1982-05-01

    The Cryogenic Safety Manual, published under the auspices of the British Cryogenics Council, is summarized. Since an awareness of the physical properties of the cryogenic fluids being dealt with is considered important in directing attention to hazardous situations which may arise, the manual lists the more important properties, such as molecular weight, boiling point, and freezing point. Since hydrogen and helium are very light, the possibility arises of explosive mixtures being formed at high points in buildings. Since argon is unexpectedly heavy, its removal requires suction rather than blowing. It is also pointed out that the use of inert liquid nitrogen can lead to the creation of a noninert atmosphere which supports combustion because it contains oxygen. Attention is also given to the danger of asphyxiation posed by the growing use of inert gases.

  16. Other Cryogenic Wind Tunnel Projects

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1997-01-01

    The first cryogenic tunnel was built at the NASA Langley Research Center in 1972. Since then, many cryogenic wind-tunnels have been built at aeronautical research centers around the world. In this lecture some of the more interesting and significant of these projects that have not been covered by other lecturers at this Special Course are described. In this lecture authors describe cryogenic wind-tunnel projects at research centers in four countries: China (Chinese Aeronautical Research and Development Center); England (College of Aeronautics at Cranfield, and Defence Research Agency - Bedford); Japan (National Aerospace Laboratory, University of Tsukuba, and National Defense Academy); and United States (Douglas Aircraft Co., University of Illinois at Urbana-Champaign, and NASA Langley).

  17. Other cryogenic wind tunnel projects

    NASA Technical Reports Server (NTRS)

    Kilgore, Robert A.

    1989-01-01

    The first cryogenic tunnel was built in 1972. Since then, many cryogenic wind-tunnel projects were started at aeronautical research centers around the world. Some of the more significant of these projects are described which are not covered by other lecturers at this Special Course. Described are cryogenic wind-tunnel projects in five countries: China (Chinese Aeronautical Research and Development Center); England (College of Aeronautics at Cranfield, and Royal Aerospace Establishment-Bedford); Japan (National Aerospace Laboratory, University of Tsukuba, and National Defense Academy); United States (Douglas Aircraft Co., University of Illinois at Urbana-Champaign and NASA Langley); and U.S.S.R. (Central Aero-Hydronamics Institute (TsAGI), Institute of Theoretical and Applied Mechanics (ITAM), and Physical-Mechanical Institute at Kharkov (PMI-K).

  18. Cryogenic needs for future tokamaks

    NASA Astrophysics Data System (ADS)

    Katheder, H.

    The ITER tokamak is a machine using superconducting magnets. The windings of these magnets will be subjected to high heat loads resulting from a combination of nuclear energy absorption and AC-losses. It is estimated that about 100 kW at 4.5 K are needed. The total cooling mass flow rate will be around 10 - 15 kg/s. In addition to the large cryogenic power required for the superconducting magnets cryogenic power is also needed for refrigerated radiation shield, various cryopumps, fuel processing and test beds. A general description of the overall layout and the envisaged refrigerator cycle, necessary cold pumps and ancillary equipment is given. The basic cryogenic layout for the ITER tokakmak design, as developed during the conceptual design phase and a short overview about existing tokamak designs using superconducting magnets is given.

  19. Status and Latest Results from the Cryogenic Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Dragowsky, Michael

    2003-10-01

    The Cryogenic Dark Matter Search (CDMS) Collaboration is engaged in the direct detection of Weakly-Interacting Massive Particles (WIMPs). The experimental signature is nuclear recoil energy resulting from spin-independent WIMP-nucleon elastic-scattering interactions in Si and Ge ZIP (Z-sensitive Ionization and Phonon-mediated) particle detectors. More generally, particle interactions are detected as recoil energy in both charge and athermal phonon channels. The two-channel readout allows for discrimination between nuclear and electron recoils, the latter resulting from radioactive and cosmogenic backgrounds. The first phase of the present experiment (CDMS II) has resulted in limits on the WIMP cross-section as a function of mass in the mass range 10-1000 GeV/c^2 from 28.3 kg days exposure on 1 kg Ge at the Stanford Underground Facility (SUF) (hep-ex/0306001 (2003)). The signal is consistent with all candidate events being due to neutrons generated from cosmic ray muon interactions in the rock surrounding this shallow experimental site. A new phase of the experiment is underway at the Soudan Mine (muon shielding overburden 2090 m.w.e.). The six detectors used in the SUF experiment are installed in the Soudan laboratory along with six additional detectors. The experimental status and latest results, including calibration and data from 1.5 kg Ge and 0.6 kg Si ZIP detectors, will be presented, as well as a look ahead to the next phase of the CDMS II experiment.

  20. Automatic control of cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Balakrishna, S.

    1989-01-01

    Inadequate Reynolds number similarity in testing of scaled models affects the quality of aerodynamic data from wind tunnels. This is due to scale effects of boundary-layer shock wave interaction which is likely to be severe at transonic speeds. The idea of operation of wind tunnels using test gas cooled to cryogenic temperatures has yielded a quantrum jump in the ability to realize full scale Reynolds number flow similarity in small transonic tunnels. In such tunnels, the basic flow control problem consists of obtaining and maintaining the desired test section flow parameters. Mach number, Reynolds number, and dynamic pressure are the three flow parameters that are usually required to be kept constant during the period of model aerodynamic data acquisition. The series of activity involved in modeling, control law development, mechanization of the control laws on a microcomputer, and the performance of a globally stable automatic control system for the 0.3-m Transonic Cryogenic Tunnel (TCT) are discussed. A lumped multi-variable nonlinear dynamic model of the cryogenic tunnel, generation of a set of linear control laws for small perturbation, and nonlinear control strategy for large set point changes including tunnel trajectory control are described. The details of mechanization of the control laws on a 16 bit microcomputer system, the software features, operator interface, the display and safety are discussed. The controller is shown to provide globally stable and reliable temperature control to + or - 0.2 K, pressure to + or - 0.07 psi and Mach number to + or - 0.002 of the set point value. This performance is obtained both during large set point commands as for a tunnel cooldown, and during aerodynamic data acquisition with intrusive activity like geometrical changes in the test section such as angle of attack changes, drag rake movements, wall adaptation and sidewall boundary-layer removal. Feasibility of the use of an automatic Reynolds number control mode with

  1. Gauging Systems Monitor Cryogenic Liquids

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Rocket fuel needs to stay cool - super cool, in fact. The ability to store gas propellants like liquid hydrogen and oxygen at cryogenic temperatures (below -243 F) is crucial for space missions in order to reduce their volumes and allow their storage in smaller (and therefore, less costly) tanks. The Agency has used these cryogenic fluids for vehicle propellants, reactants, and life support systems since 1962 with the Centaur upper stage rocket, which was powered with liquid oxygen and liquid hydrogen. During proposed long-duration missions, super-cooled fluids will also be used in space power systems, spaceports, and lunar habitation systems. In the next generation of launch vehicles, gaseous propellants will be cooled to and stored for extended periods at even colder temperatures than currently employed via a process called densification. Densification sub-cools liquids to temperatures even closer to absolute zero (-459 F), increasing the fluid s density and shrinking its volume beyond common cryogenics. Sub-cooling cryogenic liquid hydrogen, for instance, from 20 K (-423 F) to 15 K (-432.4 F) reduces its mass by 10 percent. These densified liquid gases can provide more cost savings from reduced payload volume. In order to benefit from this cost savings, the Agency is working with private industry to prevent evaporation, leakage, and other inadvertent loss of liquids and gases in payloads - requiring new cryogenic systems to prevent 98 percent (or more) of boil-off loss. Boil-off occurs when cryogenic or densified liquids evaporate, and is a concern during launch pad holds. Accurate sensing of propellants aboard space vehicles is also critical for proper engine shutdown and re-ignition after launch, and zero boil-off fuel systems are also in development for the Altair lunar lander.

  2. ERTS-C (Landsat 3) cryogenic heat pipe experiment definition

    NASA Technical Reports Server (NTRS)

    Brennan, P. J.; Kroliczek, E. J.

    1975-01-01

    A flight experiment designed to demonstrate current cryogenic heat pipe technology was defined and evaluated. The experiment package developed is specifically configured for flight aboard an ERTS type spacecraft. Two types of heat pipes were included as part of the experiment package: a transporter heat pipe and a thermal diode heat pipe. Each was tested in various operating modes. Performance data obtained from the experiment are applicable to the design of cryogenic systems for detector cooling, including applications where periodic high cooler temperatures are experienced as a result of cyclic energy inputs.

  3. Cryogenic Chamber for Servo-Hydraulic Materials Testing

    NASA Technical Reports Server (NTRS)

    Francis, John J.; Tuttle, James

    2009-01-01

    A compact cryogenic test chamber can be cooled to approximately 5 to 6 Kelvin for materials testing. The system includes a temperature controller and multiple sensors to measure specimen temperature at different locations. The testing chamber provides a fast and easy method to perform materials testing at lower than liquid nitrogen temperature (77 K). The purpose of the chamber is to cool a composite lap shear specimen to approximately 20 K so that tensile test force and displacement data may be acquired at this cryogenic temperature range.

  4. Designing of epoxy resin systems for cryogenic use

    NASA Astrophysics Data System (ADS)

    Ueki, T.; Nishijima, S.; Izumi, Y.

    2005-02-01

    The mechanical and thermal properties of several types of epoxy systems were designed based on the chemical structure, network structure and morphology aiming at cryogenic application. In this research di-epoxies or multifunctional epoxies were cured by several kinds of hardeners such as anhydride, amine or phenol and were blended with polycarbonate, carboxyl-terminated butadiene acrylonitrile copolymer or phenoxy. The mechanical properties and thermal properties of these cured epoxies were measured at room and liquid nitrogen temperature. It was found that the two-dimensional network structured linear polymer shows high performance even at cryogenic temperature. It was concluded that the controls of the structures are very important to optimize epoxy systems for cryogenic application.

  5. Cryogenic hydrogen-induced air-liquefaction technologies

    NASA Technical Reports Server (NTRS)

    Escher, William J. D.

    1990-01-01

    Extensive use of a special advanced airbreathing propulsion archives data base, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented in 1986. The resulting assessment report is summarized. Technical findings relating the status of air liquefaction technology are presented both as a singular technical area, and also as that of a cluster of collateral technical areas including: Compact lightweight cryogenic heat exchangers; Heat exchanger atmospheric constituents fouling alleviation; Para/ortho hydrogen shift conversion catalysts; Hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; Hydrogen recycling using slush hydrogen as heat sinks; Liquid hydrogen/liquid air rocket type combustion devices; Air Collection and Enrichment System (ACES); and Technically related engine concepts.

  6. Improvement of fracture toughness of epoxy resins at cryogenic temperature

    SciTech Connect

    Nishijima, S.; Yamada, K.; Hussain, M.; Honda, Y.

    1997-06-01

    The improvement of the fracture toughness of epoxy resin has been tried to perform from the molecular level with an aim to improve the cryogenic properties of GFRP and/or the stability of superconducting magnets. The ceramic filler, which was formed by hydrolysis of alkoxide, was dispersed in the epoxy and cured. A coupling agent was also used to crosslink the filler and epoxy molecules. The positron annihilation lifetime was measured and the molecular state of the epoxies were evaluated. The thermal contraction and Vickers hardness were also measured. The thermal contraction and hardness were confirmed to reflect the molecular state as evaluated by positron annihilation lifetime. The fracture toughness was also measured down to cryogenic temperatures. It was found that the improvement of the fracture toughness at cryogenic temperatures is possible.

  7. CONE - An STS-based cryogenic fluid management experiment

    NASA Technical Reports Server (NTRS)

    Bell, R. S.; Vento, D. M.; Hanna, G. J.

    1992-01-01

    An overview of the CONE program is presented which includes a definition of the technology addressed by CONE and a baseline experiment set, a description of the experimental and support subsystems, interface requirements between the STS and the experiment carrier (Hitchhiker M), and the reusability and expansion capacity for additional experiment flights. CONE evaluates three primary technologies: the active thermodynamic vent system, the passive thermodynamic vent system, and liquid acquisition device performance. The cryogenic fluid management technology database that the system offers will allow for efficient subcritical cryogenic system designs for operation in a low-gravity environment. This system maximizes the balance between existing component technology and the need for the development of a cryogenic-fluid-management (CFM) test bed to investigate and demonstrate methods of storage and handling arenas.

  8. Polyimide x-ray filter substrates optimized for cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Grove, David A.

    1999-09-01

    New generation x-ray instruments for spacecraft such as ASTRO-E and CONSTELLATION-X have very specialized requirements, notably operation at cryogenic temperatures. Luxel Corporation, under a NASA Phase I SBIR contract, undertook the demonstration of feasibility of producing polyimide films suitable for use as x-ray filter substrates specifically optimized for cryogenic applications. 5000 angstrom thick polyimide films were processed using different cure cycles, and burst pressure analyses were performed at 293, 77, and 4 Kelvin. Test data showed that polyimide films are inherently stronger at cryogenic temperatures than at room temperature. Through cure modification, film strength was increased an additional 9 percent at 4K over that of the standard cure clearly showing the feasibility of film optimization.

  9. Space station experiment definition: Long term cryogenic fluid storage

    NASA Technical Reports Server (NTRS)

    Riemer, David H.

    1987-01-01

    A preliminary design of an experiment to demonstrate and evaluate long-term cryogenic fluid storage and transfer technologies has been performed. This Long-Term Cryogenic Fluid Storage (LTCFS) experiment is a Technology Development Mission (TDM) experiment proposed by the NASA Lewis Research Center to be deployed on the Initial Operational Capability (IOC) space station. Technologies required by future orbital cryogenic systems such as Orbital Transfer Vehicles (OTV's) were defined, and critical technologies requiring demonstration were chosen to be included in the experiment. A three-phase test program was defined to test the following types of technologies: (1) Passive Thermal Technologies; (2) Fluid Transfer Technologies; and (3) Active Refrigeration Technologies. The development status of advanced technologies required for the LTCFS experiment is summarized, including current, past and future programs.

  10. Overview of RICOR tactical cryogenic refrigerators for space missions

    NASA Astrophysics Data System (ADS)

    Riabzev, Sergey; Filis, Avishai; Livni, Dorit; Regev, Itai; Segal, Victor; Gover, Dan

    2016-05-01

    Cryogenic refrigerators represent a significant enabling technology for Earth and Space science enterprises. Many of the space instruments require cryogenic refrigeration to enable the use of advanced detectors to explore a wide range of phenomena from space. RICOR refrigerators involved in various space missions are overviewed in this paper, starting in 1994 with "Clementine" Moon mission, till the latest ExoMars mission launched in 2016. RICOR tactical rotary refrigerators have been incorporated in many space instruments, after passing qualification, life time, thermal management testing and flight acceptance. The tactical to space customization framework includes an extensive characterization and qualification test program to validate reliability, the design of thermal interfacing with a detector, vibration export control, efficient heat dissipation in a vacuum environment, robustness, mounting design, compliance with outgassing requirements and strict performance screening. Current RICOR development is focused on dedicated ultra-long-life, highly reliable, space cryogenic refrigerator based on a Pulse Tube design

  11. Metabonomic study on the plasma of streptozotocin-induced diabetic rats treated with Ge Gen Qin Lian Decoction by ultra high performance liquid chromatography-mass spectrometry.

    PubMed

    Zhang, Qiyun; Xu, Guoliang; Li, Jia; Guo, Xiaofeng; Wang, Hong; Li, Bingtao; Tu, Jun; Zhang, Huashan

    2016-02-20

    Changes in endogenous metabolites in the plasma of streptozotocin (STZ)-induced diabetic rats treated with Ge Gen Qin Lian Decoction (GGQLD) were studied. The endogenous compounds in plasma were detected using ultra high performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS). Rats were divided into three groups: control, model, and administration (4.95g crude drug/kg body weight). After the final administration, plasma samples from the three groups were analyzed using metabonomics. The three sample groups could be clearly distinguished. The administration group exhibited a distinct return to the levels of phytosphingosine and dihydrosphingosine of the control group according to the principal component analysis score, and the corresponding biomarkers were defined. Significant changes in endogenous metabolites, such as dihydrosphingosine, phytosphingosine, cholylglycine, and pantothenic acid, were identified in STZ-induced diabetic rats. These biochemical changes are associated with the metabolism of sphingolipids, fats, and acetyl coenzyme-A, which could be useful to further investigate the characteristics of STZ-induced diabetes mellitus and the therapeutic mechanism of action of GGQLD. This metabonomic analysis could provide a useful starting point toelucidate the therapeutic effects and mechanism of action of GGQLD in diabetes mellitus.

  12. Cryogenic thermal diode heat pipes

    NASA Technical Reports Server (NTRS)

    Alario, J.

    1979-01-01

    The development of spiral artery cryogenic thermal diode heat pipes was continued. Ethane was the working fluid and stainless steel the heat pipe material in all cases. The major tasks included: (1) building a liquid blockage (blocking orifice) thermal diode suitable for the HEPP space flight experiment; (2) building a liquid trap thermal diode engineering model; (3) retesting the original liquid blockage engineering model, and (4) investigating the startup dynamics of artery cryogenic thermal diodes. An experimental investigation was also conducted into the wetting characteristics of ethane/stainless steel systems using a specially constructed chamber that permitted in situ observations.

  13. Optical Cryogenic Tank Level Sensor

    NASA Technical Reports Server (NTRS)

    Duffell, Amanda

    2005-01-01

    Cryogenic fluids play an important role in space transportation. Liquid oxygen and hydrogen are vital fuel components for liquid rocket engines. It is also difficult to accurately measure the liquid level in the cryogenic tanks containing the liquids. The current methods use thermocouple rakes, floats, or sonic meters to measure tank level. Thermocouples have problems examining the boundary between the boiling liquid and the gas inside the tanks. They are also slow to respond to temperature changes. Sonic meters need to be mounted inside the tank, but still above the liquid level. This causes problems for full tanks, or tanks that are being rotated to lie on their side.

  14. Aerogel Beads as Cryogenic Thermal Insulation System

    NASA Technical Reports Server (NTRS)

    Fesmire, J. E.; Augustynowicz, S. D.; Rouanet, S.; Thompson, Karen (Technical Monitor)

    2001-01-01

    An investigation of the use of aerogel beads as thermal insulation for cryogenic applications was conducted at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Steady-state liquid nitrogen boiloff methods were used to characterize the thermal performance of aerogel beads in comparison with conventional insulation products such as perlite powder and multilayer insulation (MLI). Aerogel beads produced by Cabot Corporation have a bulk density below 100 kilograms per cubic meter (kg/cubic m) and a mean particle diameter of 1 millimeter (mm). The apparent thermal conductivity values of the bulk material have been determined under steady-state conditions at boundary temperatures of approximately 293 and 77 kelvin (K) and at various cold vacuum pressures (CVP). Vacuum levels ranged from 10(exp -5) torr to 760 torr. All test articles were made in a cylindrical configuration with a typical insulation thickness of 25 mm. Temperature profiles through the thickness of the test specimens were also measured. The results showed the performance of the aerogel beads was significantly better than the conventional materials in both soft-vacuum (1 to 10 torr) and no-vacuum (760 torr) ranges. Opacified aerogel beads performed better than perlite powder under high-vacuum conditions. Further studies for material optimization and system application are in progress.

  15. Power control electronics for cryogenic instrumentation

    NASA Technical Reports Server (NTRS)

    Ray, Biswajit; Gerber, Scott S.; Patterson, Richard L.; Myers, Ira T.

    1995-01-01

    In order to achieve a high-efficiency high-density cryogenic instrumentation system, the power processing electronics should be placed in the cold environment along with the sensors and signal-processing electronics. The typical instrumentation system requires low voltage dc usually obtained from processing line frequency ac power. Switch-mode power conversion topologies such as forward, flyback, push-pull, and half-bridge are used for high-efficiency power processing using pulse-width modulation (PWM) or resonant control. This paper presents several PWM and multiresonant power control circuits, implemented using commercially available CMOS and BiCMOS integrated circuits, and their performance at liquid-nitrogen temperature (77 K) as compared to their room temperature (300 K) performance. The operation of integrated circuits at cryogenic temperatures results in an improved performance in terms of increased speed, reduced latch-up susceptibility, reduced leakage current, and reduced thermal noise. However, the switching noise increased at 77 K compared to 300 K. The power control circuits tested in the laboratory did successfully restart at 77 K.

  16. High temperature thermoelectric transport properties of p-type Ba8Ga16AlxGe30-x type-I clathrates with high performance

    NASA Astrophysics Data System (ADS)

    Deng, Shukang; Tang, Xinfeng; Li, Peng; Zhang, Qingjie

    2008-04-01

    Using group-III atom Al as doping element, Ba8Ga16AlxGe30-x (x =1.0, 2.0, 3.0, 4.0, and 5.0) type-I clathrates with different Al content were synthesized by combining melting reaction with spark plasma sintering method. The effects of Al content on thermoelectric properties are investigated. X-ray diffraction patterns and Rietveld analysis reveal that the compounds prepared by this method are type-I clathrates and Al atom preference for the 6c site. The Al substitutions do not affect the atomic displacement parameters (ADPs) of framework atoms (Ge/Ga) and filled atoms (Ba) compared to that of Ba8Ga16Ge30, and the ADPs of Al are nearly equivalent to that of other framework Ge /Ga atoms. All specimens exhibit the behavior of the p-type conduction. The carrier concentration and electrical conductivity increase while Seebeck coefficient decreases with the increasing Al content for the specimens with ⩽4.0. Ba8Ga16Al3.0Ge27.0 compound possesses the relatively lower lattice thermal conductivity κL due to the mass fluctuation between Al atoms and other atoms in the framework; it is as low as 0.96W/mK at 300K. The maximum ZT value of 0.61 is obtained at 760K for Ba8Ga16Al3.0Ge27.0.

  17. The cryogenic wind tunnel for high Reynolds number testing. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Kilgore, R. A.

    1974-01-01

    Experiments performed at the NASA Langley Research Center in a cryogenic low-speed continuous-flow tunnel and in a cryogenic transonic continuous-flow pressure tunnel have demonstrated the predicted changes in Reynolds number, drive power, and fan speed with temperature, while operating with nitrogen as the test gas. The experiments have also demonstrated that cooling to cryogenic temperatures by spraying liquid nitrogen directly into the tunnel circuit is practical and that tunnel temperature can be controlled within very close limits. Whereas most types of wind tunnel could operate with advantage at cryogenic temperatures, the continuous-flow fan-driven tunnel is particularly well suited to take full advantage of operating at these temperatures. A continuous-flow fan-driven cryogenic tunnel to satisfy current requirements for test Reynolds number can be constructed and operated using existing techniques. Both capital and operating costs appear acceptable.

  18. Cryogenic Supply for the Gerda Experiment

    NASA Astrophysics Data System (ADS)

    Haberstroh, Ch.

    2008-03-01

    In the GERDA experiment (GERmanium Detector Array for the search of neutrinoless double beta decay of 76Ge) germanium diodes are suspended in a superinsulated cryostat filled with 70 m3 of liquid argon. The cold medium is required since the diodes have to be operated at low temperatures, and furthermore for shielding against background radiation. For the same reason the whole experiment will be placed in the underground laboratories in the Gran Sasso mountains, Italy. In order to avoid any detrimental perturbation inside the dewar vessel, the liquid-argon (LAr) inventory in the main tank will be kept in a subcooled state at a working pressure of 0.12 MPa absolute at the surface. At the TU Dresden an appropriate cryogenic arrangement was designed to match these requirements. Liquid nitrogen (LN2) is used as a cooling fluid. Special care was taken to cope with the narrow temperature span between the LAr boiling temperature and triple point. In the proposed solution a subcooler located close to the cryostat neck provides a stable LAr convection inside the main tank. The working pressure is adjusted with a controlled, slightly elevated temperature level at the liquid-vapor interface.

  19. Tests Of A Magnetic Bearing For Cryogenic Applications

    NASA Technical Reports Server (NTRS)

    Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Report describes experiments performed in test rig on hybrid magnetic bearing for possible use in turbopumps at low temperature. Results of tests indicate feasible to use bearing in cryogenic environments and bearing damps bending-mode vibrations of flexible rotor as rotor accelerates or decelerates through speeds at which bending-mode oscillations excited.

  20. Shuttle cryogenic supply system optimization study. Volume 6: Appendixes

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The optimization of the cryogenic supply system for space shuttles is discussed. The subjects considered are: (1) auxiliary power unit parametric data, (2) propellant acquisition, (3) thermal protection and thermodynamic properties, (4) instrumentation and controls, and (5) initial component redundancy evaluations. Diagrams of the systems are provided. Graphs of the performance capabilities are included.

  1. Long-Term Cryogenic Propellant Storage for the Titan Orbiter Polar Surveyor (TOPS) Mission

    NASA Technical Reports Server (NTRS)

    Mustafi, Shuvo; Francis, John; Li, Xiaoyi; DeLee, Hudson; Purves, Lloyd; Willis, Dewey; Nixon, Conor; Mcguinness, Dan; Riall, Sara; Devine, Matt; Hedayat, Ali

    2015-01-01

    Cryogenic propellants such as liquid hydrogen (LH2) and liquid oxygen (LOX) can dramatically enhance NASAs ability to explore the solar system because of their superior specific impulse (Isp) capability. Although these cryogenic propellants can be challenging to manage and store, they allow significant mass advantages over traditional hypergolic propulsion systems and are therefore technically enabling for many planetary science missions. New cryogenic storage techniques such as subcooling and the use of advanced insulation and low thermal conductivity support structures will allow for the long term storage and use of cryogenic propellants for solar system exploration and hence allow NASA to deliver more payloads to targets of interest, launch on smaller and less expensive launch vehicles, or both. Employing cryogenic propellants will allow NASA to perform missions to planetary destinations that would not be possible with the use of traditional hypergolic propellants. These new cryogenic storage technologies were implemented in a design study for the Titan Orbiter Polar Surveyor (TOPS) mission, with LH2 and LOX as propellants, and the resulting spacecraft design was able to achieve a 43 launch mass reduction over a TOPS mission, that utilized a conventional hypergolic propulsion system with mono-methyl hydrazine (MMH) and nitrogen tetroxide (NTO) propellants. This paper describes the cryogenic propellant storage design for the TOPS mission and demonstrates how these cryogenic propellants are stored passively for a decade-long Titan mission.

  2. Cryogenic Insulation System for Soft Vacuum

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, J. E.

    1999-01-01

    The development of a cryogenic insulation system for operation under soft vacuum is presented in this paper. Conventional insulation materials for cryogenic applications can be divided into three levels of thermal performance, in terms of apparent thermal conductivity [k-value in milliwatt per meter-kelvin (mW/m-K)]. System k-values below 0.1 can be achieved for multilayer insulation operating at a vacuum level below 1 x 10(exp -4) torr. For fiberglass or powder operating below 1 x 10(exp -3) torr, k-values of about 2 are obtained. For foam and other materials at ambient pressure, k-values around 30 are typical. New industry and aerospace applications require a versatile, robust, low-cost thermal insulation with performance in the intermediate range. The target for the new composite insulation system is a k-value below 4.8 mW/m-K (R-30) at a soft vacuum level (from 1 to 10 torr) and boundary temperatures of approximately 77 and 293 kelvin (K). Many combinations of radiation shields, spacers, and composite materials were tested from high vacuum to ambient pressure using cryostat boiloff methods. Significant improvement over conventional systems in the soft vacuum range was demonstrated. The new layered composite insulation system was also shown to provide key benefits for high vacuum applications as well.

  3. Sandwich Cylinder Technology for Cryogenic Tank

    NASA Astrophysics Data System (ADS)

    Rambaud, Wladimir; Lukowiak, Denis; Damas, Alain; Michelot, David; Jousset, Frederic; Mercier, Antoine; Bouilly, Thibault; Leudiere, Vincent

    2014-06-01

    In the frame of the Research and Technology activities, CNES Launcher Directorate and EuroCryospace performed studies on cryogenic tank.Since 2009/2010, we realized analyses and tests on a promising technology for cryogenic tank submitted to high compressive loads. Indeed, the "Sandwich cylinder" (metallic shell, insulating core, composite shell) is a way to improve performance and costs with respect to classical structure. This concept presents specific stiffness behavior (advantageous stiffness/mass ratio) higher than an aluminum alloy structure and scalable thermal behavior.The relevancy of the Sandwich concept was first evaluated by calculation in comparison with 3 other cylinder architectures and then this R&T project was conducted from elementary characterizations to a buckling test of a representative demonstrator.The paper provides an overview of the different steps of the project and the main results obtained. Potential benefits for Ariane 6 launcher are also presented.The concept is submitted to ECSP patent and so, numerical values will not be present in the paper.

  4. Background reduction in cryogenic detectors

    SciTech Connect

    Bauer, Daniel A.; /Fermilab

    2005-04-01

    This paper discusses the background reduction and rejection strategy of the Cryogenic Dark Matter Search (CDMS) experiment. Recent measurements of background levels from CDMS II at Soudan are presented, along with estimates for future improvements in sensitivity expected for a proposed SuperCDMS experiment at SNOLAB.

  5. Dust Charge in Cryogenic Environment

    SciTech Connect

    Kubota, J.; Kojima, C.; Sekine, W.; Ishihara, O.

    2008-09-07

    Dust charges in a complex helium gas plasma, surrounded by cryogenic liquid, are studied experimentally. The charge is determined by frequency and equilibrium position of damped dust oscillation proposed by Tomme et al.(2000) and is found to decrease with ion temperature of the complex plasma.

  6. Ames Research Center cryogenics program

    NASA Technical Reports Server (NTRS)

    Kittel, Peter

    1987-01-01

    Viewgraphs describe the Ames Research Center's cryogenics program. Diagrams are given of a fluid management system, a centrifugal pump, a flow meter, a liquid helium test facility, an extra-vehicular activity coupler concept, a dewar support with passive orbital disconnect, a pulse tube refrigerator, a dilution refrigerator, and an adiabatic demagnetization cooler.

  7. Level Sensor for Cryogenic Fluids

    NASA Technical Reports Server (NTRS)

    Simmons, N. E.; Schroff, R. A.

    1983-01-01

    Hot wire sensor combined with voltage-comparator circuit monitors liquid level in cryogenic-fluid storage tanks. Sensor circuit adaptable to different liquids and sensors. Constant-current source drives current through sensing probe and fixed resistor. Voltage comparator circuits interpret voltage drops to tell whether probe is immersed in liquid and is current in probe.

  8. Status Of Sorption Cryogenic Refrigeration

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1988-01-01

    Report reviews sorption refrigeration. Developed for cooling infrared detectors, cryogenic research, and other advanced applications, sorption refrigerators have few moving parts, little vibration, and lifetimes of 10 years or more. Describes types of sorption stages, multistage and hybrid refrigeration systems, power requirements, cooling capacities, and advantages and disadvantages of various stages and systems.

  9. Cryogenic Tank Technology Program (CTTP)

    NASA Technical Reports Server (NTRS)

    Vaughn, T. P.

    2001-01-01

    The objectives of the Cryogenic Tank Technology Program were to: (1) determine the feasibility and cost effectiveness of near net shape hardware; (2) demonstrate near net shape processes by fabricating large scale-flight quality hardware; and (3) advance state of current weld processing technologies for aluminum lithium alloys.

  10. Foam shell cryogenic ICF target

    DOEpatents

    Darling, Dale H.

    1987-01-01

    A uniform cryogenic layer of DT fuel is maintained in a fusion target having a low density, small pore size, low Z rigid foam shell saturated with liquid DT fuel. Capillary action prevents gravitational slumping of the fuel layer. The saturated shell may be cooled to produce a solid fuel layer.

  11. A Magnetically Coupled Cryogenic Pump

    NASA Technical Reports Server (NTRS)

    Hatfield, Walter; Jumper, Kevin

    2011-01-01

    Historically, cryogenic pumps used for propellant loading at Kennedy Space Center (KSC) and other NASA Centers have a bellows mechanical seal and oil bath ball bearings, both of which can be problematic and require high maintenance. Because of the extremely low temperatures, the mechanical seals are made of special materials and design, have wearing surfaces, are subject to improper installation, and commonly are a potential leak path. The ball bearings are non-precision bearings [ABEC-1 (Annular Bearing Engineering Council)] and are lubricated using LOX compatible oil. This oil is compatible with the propellant to prevent explosions, but does not have good lubricating properties. Due to the poor lubricity, it has been a goal of the KSC cryogenics community for the last 15 years to develop a magnetically coupled pump, which would eliminate these two potential issues. A number of projects have been attempted, but none of the pumps was a success. An off-the-shelf magnetically coupled pump (typically used with corrosive fluids) was procured that has been used for hypergolic service at KSC. The KSC Cryogenics Test Lab (CTL) operated the pump in cryogenic LN2 as received to determine a baseline for modifications required. The pump bushing, bearings, and thrust rings failed, and the pump would not flow liquid (this is a typical failure mode that was experienced in the previous attempts). Using the knowledge gained over the years designing and building cryogenic pumps, the CTL determined alternative materials that would be suitable for use under the pump design conditions. The CTL procured alternative materials for the bearings (bronze, aluminum bronze, and glass filled PTFE) and machined new bearing bushings, sleeves, and thrust rings. The designed clearances among the bushings, sleeves, thrust rings, case, and case cover were altered once again using experience gained from previous cryogenic pump rebuilds and designs. The alternative material parts were assembled into

  12. Centaur Test Bed (CTB) for Cryogenic Fluid Management

    NASA Technical Reports Server (NTRS)

    Sakla, Steven; Kutter, Bernard; Wall, John

    2006-01-01

    Future missions such as NASA s space exploration vision and DOD satellite servicing will require significant increases in the understanding and knowledge of space based cryogenic fluid management (CFM), including the transfer and storage of cryogenic fluids. Existing CFM capabilities are based on flight of upper stage cryogenic vehicles, scientific dewars, a few dedicated flight demonstrations and ground testing. This current capability is inadequate to support development of the CEV cryogenic propulsion system, other aspects of robust space exploration or the refueling of satellite cryo propulsion systems with reasonable risk. In addition, these technologies can provide significant performance increases for missions beyond low-earth orbit to enable manned missions to the Moon and beyond. The Centaur upper-stage vehicle can provide a low cost test platform for performing numerous flight demonstrations of the full breadth of required CFM technologies to support CEV development. These flight demonstrations can be performed as secondary mission objectives using excess LH2 and/or LO2 from the main vehicle propellant tanks following primary spacecraft separation at minimal cost and risk.

  13. Cryogenic Field Measurement of Pr{sub 2}Fe{sub 14}B Undulator and Performance Enhancement Options at the NSLS-II

    SciTech Connect

    Tanabe, Toshiya; Chubar, Oleg; Harder, David A.; Rank, James; Spataro, Charles; Lehecka, Michael; Rakowsky, George

    2010-06-23

    Short period (14.5mm) hybrid undulator arrays composed of Praseodymium Iron Boron (Pr{sub 2}Fe{sub 14}B) magnets (CR53, NEOMAX, Inc.) and vanadium permendur poles have been fabricated at Brookhaven National Laboratory. Unlike Neodymium Iron Boron (Nd{sub 2}Fe{sub 14}B) magnets which exhibit spin reorientation at a temperatures below 150 K, PrFeB arrays monotonically increase performance with lower operating temperature. It opens up the possibility for use in operating a cryo-permanent magnet undulator (CPMU) in the range of 40 K to 60 K where very efficient cryocoolers are available. Magnetic flux density profiles were measured at various temperature ranges from room temperature down to liquid helium (LHe) using the Vertical Testing Facility (VTF) at the National Synchrotron Light Source-II (NSLS-II). Temperature variations of phase error have been characterized. In addition, we examined the use of textured Dysprosium (Dy) poles to replace permendur poles to obtain further improvement in performance.

  14. Stressed and unstressed Ge:Ga detector arrays for airborne astronomy

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Beeman, J. W.; Haller, E. E.; Geis, N.; Poglitsch, A.; Rumitz, M.

    1992-01-01

    The construction and operation of 2D arrays of both unstressed and stressed Ge:Ga photoconductive detectors for far-IR astronomy from the Kuiper Airborne Observatory is presented. The 25 element (5 x 5) arrays are designed for a new cryogenically cooled spectrometer. The 2D spatial array described has the advantage of absolute registry between pixels in a map.

  15. Testing the equipment for the cryogenic optical test of the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Whitman, Tony L.; Dziak, K. J.; Huguet, Jesse; Knight, J. Scott; Reis, Carl; Wilson, Erin

    2014-08-01

    After integration of the Optical Telescope Element (OTE) to the Integrated Science Instrument Module (ISIM) to become the OTIS, the JWST optics are tested at NASA's Johnson Space Center (JSC) in the cryogenic vacuum Chamber A for alignment and optical performance. Tens of trucks full of custom test equipment are being delivered to the JSC, in addition to the large pieces built at the Center, and the renovation of the chamber itself. The facility is tested for the thermal stability control for optical measurements and contamination control during temperature transitions. The support for the OTIS is also tested for thermal stability control, load tested in the cryogenic environment, and tested for isolation of the background vibration for the optical measurements. The Center of Curvature Optical Assembly (COCOA) is tested for the phasing and wavefront error (WFE) measurement of an 18 segment mirror and for cryogenic operation. A photogrammetry system is tested for metrology performance and cryogenic operation. Test mirrors for auto-collimation measurements are tested for optical performance and cryogenic operation. An assembly of optical test sources are calibrated and tested in a cryogenic environment. A Pathfinder telescope is used as a surrogate telescope for cryogenic testing of the OTIS optical test configuration. A Beam Image Analyzer (BIA) is used as a surrogate ISIM with the Pathfinder in this test. After briefly describing the OTIS optical test configuration, the paper will overview the list and configuration of significant tests of the equipment leading up to the OTIS test.

  16. SPICA sub-Kelvin cryogenic chains

    NASA Astrophysics Data System (ADS)

    Duband, L.; Duval, J. M.; Luchier, N.; Prouve, T.

    2012-04-01

    SPICA, a Japanese led mission, is part of the JAXA future science program and is planned for launch in 2018. SPICA will perform imaging and spectroscopic observations in the mid- and far-IR waveband, and is developing instrumentation spanning the 5-400 μm range. The SPICA payload features several candidate instruments, some of them requiring temperature down to 50 mK. This is currently the case for SAFARI, a core instrument developed by a European-based consortium, and BLISS proposed by CALTECH/JPL in the US. SPICA's distinctive feature is to actively cool its telescope to below 6 K. In addition, SPICA is a liquid cryogen free satellite and all the cooling will be provided by radiative cooling (L2 orbit) down to 30 K and by mechanical coolers for lower temperatures. The satellite will launch warm and slowly equilibrate to its operating temperatures once in orbit. This warm launch approach makes it possible to eliminate a large liquid cryogen tank and to use the mass saved to launch a large diameter telescope (3.2 m). This 4 K cooled telescope significantly reduces its own thermal radiation, offering superior sensitivity in the infrared region. The cryogenic system that enables this warm launch/cooled telescope concept is a key issue of the mission. This cryogenic chain features a number of cooling stages comprising passive radiators, Stirling coolers and several Joule Thomson loops, offering cooling powers at typically 20, 4.5, 2.5 and 1.7 K. The SAFARI and BLISS detectors require cooling to temperatures as low as 50 mK. The instrument coolers will be operated from these heat sinks. They are composed of a small demagnetization refrigerator (ADR) pre cooled by either a single or a double sorption cooler, respectively for SAFARI and BLISS. The BLISS cooler maintains continuous cooling at 300 mK and thus suppresses the thermal equilibrium time constant of the large focal plane. These hybrid architectures allow designing low weight coolers able to reach 50 mK. Because

  17. Centaur Standard Shroud (CSS) cryogenic unlatch tests

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Cryogenic tanking and partial jettison (unlatch) tests were performed on a full scale Centaur vehicle and Centaur Standard Shroud (CSS) to develop and qualify the CSS insulation system, the CSS and Centaur ground-hold purge systems, and the Centaur hydrogen tank flight vent system. Operation of the shroud/Centaur pyrotechnic systems, seals, and the shroud jettison springs, hinges, and other separation systems was demonstrated by a partial jettison of the shroud into catch nets. The Centaur tanks were filled with liquid hydrogen and liquid nitrogen. Prelaunch operations were performed, and data taken to establish system performances. Results from the initial tests showed a higher than expected heat transfer rate to the Centaur hydrogen tank. In addition, the release mechanism for the forward seal between the Centaur and the CSS did not function properly, and the seal was torn during jettison of the shroud.

  18. Identifying electronic properties relevant to improving stability in a-Si:H-based cells and overall performance in a-Si,Ge:H-based cells. Annual subcontract report, 18 April 1995--17 April 1996

    SciTech Connect

    Cohen, J.D.

    1997-03-01

    The work done during this second phase of the University of Oregon`s NREL subcontract focused on degradation studies in both pure a-Si:H and a-Si,Ge:H alloys, as well as a detailed study of the interface between these two materials in a-Si:H/a-Si, Ge:H heterostructures. All samples discussed in this report were produced by the glow-discharge method and were obtained either in collaboration with United Solar Systems Corporation or with researchers at Lawrence Berkeley laboratory. First, the results from the a-Si, Ge:H degradation studies support the conclusion that considerable quantities of charged defects exist in nominally intrinsic material. Researchers found that on light-soaking, all the observed defect sub-bands increased; however, their ratios varied significantly. Second, researchers performed voltage pulse stimulated capacitance transient measurements on a-Si:H/a-Si, Ge:H heterostructure samples and found a clear signature of trapped hole emission extending over long times. Finally, researchers began comparison studies of the electronic properties of a-Si:H grown by glow discharge either with 100% silane, or with silane diluted in H{sub 2} or He gas. The results on these samples indicate that the films grown under high hydrogen dilution exhibit roughly a factor of 3 lower deep defect densities than those grown using pure silane.

  19. Use of Thermoset Composite Materials in Cryogenic Tanks

    NASA Astrophysics Data System (ADS)

    Diaz, V.; Cardone, T.; Ramusat, G.

    2014-06-01

    To improve the performances of Future Expendable Launchers, one of the key aspects to be considered is the mass optimization of the cryogenic upper stage of the launcher, where a mass saving of one Kg, is directly transferred to one more Kg of payload.This optimization is inherently linked to the use of composite materials in all the structures that conforms the upper stage of the launcher.Currently, most of the upper stage structures of the operational launchers, like Ariane 5, are made in composite materials, with the exception of the cryogenic (LH2 and LOX) tanks which remain metallic.So, from a structural point of view, the next qualitative step in the development of new expendable launcher, would be the manufacturing of the upper stage cryogenic tanks in composite materials.To reach this objective important concerns mainly related to the potential for leaks and the compatibility with the LOX need to be resolved.In the frame of the FLPP (Future Launcher Preparatory Program) funded by ESA, an activity related to the use of thermoset composite material in the cryogenic tanks has been included.This paper presents a summary of the performed work which includes:* The selection and characterization of the most suitable candidate materials for the considered application* The design and analysis of a subscale demonstrator representative of the LH2 compartment* The design, manufacturing and testing of some test articles representatives of the selected design solutions* The manufacturing and testing of the selected subscale demonstrator.

  20. Superfluid helium cryogenic systems for superconducting RF cavities at KEK

    SciTech Connect

    Nakai, H.; Hara, K.; Honma, T.; Hosoyama, K.; Kojima, Y.; Nakanishi, K.; Kanekiyo, T.; Morita, S.

    2014-01-29

    Recent accelerator projects at KEK, such as the Superconducting RF Test Facility (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium, which can generate high gradient acceleration field. Since the operation temperature of these cavities is selected to be 2 K, we have developed two 2 K superfluid helium cryogenic systems for stable operation of superconducting RF cavities for each of STF and cERL. These two 2 K superfluid helium cryogenic systems are identical in principle. Since the operation mode of the cavities is different for STF and cERL, i.e. the pulse mode for STF and the continuous wave mode for cERL, the heat loads from the cavities are quite different. The 2 K superfluid helium cryogenic systems mainly consists of ordinary helium liquefiers/refrigerators, 2 K refrigerator cold boxes, helium gas pumping systems and high-performance transfer lines. The 2 K refrigerators and the high-performance transfer lines are designed by KEK. Some superconducting RF cavity cryomodules have been already connected to the 2 K superfluid helium cryogenic systems for STF and cERL respectively, and cooled down to 2 K successfully.

  1. CryoPAF4: a cryogenic phased array feed design

    NASA Astrophysics Data System (ADS)

    Locke, Lisa; Garcia, Dominic; Halman, Mark; Henke, Doug; Hovey, Gary; Jiang, Nianhua; Knee, Lewis; Lacy, Gordon; Loop, David; Rupen, Michael; Veidt, Bruce; Wierzbicki, Ramunas

    2016-07-01

    Phased array feed (PAF) receivers used on radio astronomy telescopes offer the promise of increased fields of view while maintaining the superlative performance attained with traditional single pixel feeds (SPFs). However, the much higher noise temperatures of room temperature PAFs compared to cryogenically-cooled SPFs have prevented their general adoption. Here we describe a conceptual design for a cryogenically cooled 2.8 - 5.18 GHz dual linear polarization PAF with estimated receiver temperature of 11 K. The cryogenic PAF receiver will comprise a 140 element Vivaldi antenna array and low-noise amplifiers housed in a 480 mm diameter cylindrical dewar covered with a RF transparent radome. A broadband two-section coaxial feed is integrated within each metal antenna element to withstand the cryogenic environment and to provide a 50 ohm impedance for connection to the rest of the receiver. The planned digital beamformer performs digitization, frequency band selection, beam forming and array covariance matrix calibration. Coupling to a 15 m offset Gregorian dual-reflector telescope, cryoPAF4 can expect to form 18 overlapping beams increasing the field of view by a factor of 8x compared to a single pixel receiver of equal system temperature.

  2. Cryogenic setup for trapped ion quantum computing.

    PubMed

    Brandl, M F; van Mourik, M W; Postler, L; Nolf, A; Lakhmanskiy, K; Paiva, R R; Möller, S; Daniilidis, N; Häffner, H; Kaushal, V; Ruster, T; Warschburger, C; Kaufmann, H; Poschinger, U G; Schmidt-Kaler, F; Schindler, P; Monz, T; Blatt, R

    2016-11-01

    We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternating magnetic field noise, resulting in 120 dB reduction of 50 Hz noise along the magnetic field axis. We combine this efficient magnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of optical qubits due to the motion of the cryostat. We measure vibrations of the cryostat of less than ±20 nm over 2 s. In addition to the cryogenic apparatus, we describe the setup required for an operation with (40)Ca(+) and (88)Sr(+) ions. The instability of the laser manipulating the optical qubits in (40)Ca(+) is characterized by yielding a minimum of its Allan deviation of 2.4 ⋅ 10(-15) at 0.33 s. To evaluate the performance of the apparatus, we trapped (40)Ca(+) ions, obtaining a heating rate of 2.14(16) phonons/s and a Gaussian decay of the Ramsey contrast with a 1/e-time of 18.2(8) ms.

  3. Cryogenic setup for trapped ion quantum computing

    NASA Astrophysics Data System (ADS)

    Brandl, M. F.; van Mourik, M. W.; Postler, L.; Nolf, A.; Lakhmanskiy, K.; Paiva, R. R.; Möller, S.; Daniilidis, N.; Häffner, H.; Kaushal, V.; Ruster, T.; Warschburger, C.; Kaufmann, H.; Poschinger, U. G.; Schmidt-Kaler, F.; Schindler, P.; Monz, T.; Blatt, R.

    2016-11-01

    We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenuate alternating magnetic field noise, resulting in 120 dB reduction of 50 Hz noise along the magnetic field axis. We combine this efficient magnetic shielding with high optical access required for single ion addressing as well as for efficient state detection by placing two lenses each with numerical aperture 0.23 inside the inner heat shield. The cryostat design incorporates vibration isolation to avoid decoherence of optical qubits due to the motion of the cryostat. We measure vibrations of the cryostat of less than ±20 nm over 2 s. In addition to the cryogenic apparatus, we describe the setup required for an operation with 40Ca+ and 88Sr+ ions. The instability of the laser manipulating the optical qubits in 40Ca+ is characterized by yielding a minimum of its Allan deviation of 2.4 ṡ 10-15 at 0.33 s. To evaluate the performance of the apparatus, we trapped 40Ca+ ions, obtaining a heating rate of 2.14(16) phonons/s and a Gaussian decay of the Ramsey contrast with a 1/e-time of 18.2(8) ms.

  4. Cryogen free cryostat for neutron scattering experiments

    NASA Astrophysics Data System (ADS)

    Kirichek, O.; Down, R. B. E.; Manuel, P.; Keeping, J.; Bowden, Z. A.

    2014-12-01

    Most very low temperature (below 1K) experiments at advanced neutron facilities are based on dilution and 3He refrigerator inserts used with Orange cryostats, or similar systems. However recent increases in the cost of liquid helium caused by global helium supply problems, has raised significant concern about the affordability of such cryostats. Here we present the design and test results of a cryogen free top-loading cryostat with a standard KelvinoxVT® dilution refrigerator insert which provides sample environment for neutron scattering experiments in the temperature range 35 mK - 300 K. The dilution refrigerator insert operates in a continuous regime. The cooling time of the insert is similar to one operated in the Orange cryostat. The main performance criteria such as base temperature, cooling power, and circulation rate are compatible with the technical specification of a standard dilution refrigerator. In fact the system offers operating parameters very similar to those of an Orange cryostat, but without the complication of cryogens. The first scientific results obtained in ultra-low temperature neutron scattering experiment with this system are also going to be discussed.

  5. Cryogenics and the Human Exploration of Mars

    NASA Technical Reports Server (NTRS)

    Salerno, Louis J.; Kittel, Peter; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    Current plans within NASA involve extending the human exploration of space from low earth orbit into the solar system, with the first human exploration of Mars presently planned in 2011. Integral to all hum Mars mission phases is cryogenic fluid management. Cryogenic fluids will be required both as propellant and for In-Situ Resource Utilization (ISRU). Without safe and efficient cryogen storage human Mars missions will not be possible. Effective control and handling of cryogenic fluids is the key to affordable Mars missions, and advancing active thermal control technology is synergistic with all of NASA's exploration initiatives and with existing and future instrument cooling programs, including MTPE and Origins. Present mission scenarios for human exploration require cryogenic propellant storage for up to 1700 days and for up to 60 metric tons. These requirements represent increases of an order of magnitude over previous storage masses and lifetimes. The key cryogenic terminology areas to be addressed in human Mars missions are long-term propellant storage, cryogenic refrigeration, cryogenic liquefaction, and zero gravity fluid management. Long-term storage for the thermal control of cryogenic propellants is best accomplished with a mix of passive and active technologies. Passive technologies such as advanced multilayer insulation (MLI) concepts will be combined with the development of active coolers (cryogenic refrigerators). Candidates for long-life active cooling applications include Reverse Turbo-Brayton, Stirling, and Pulse-Tube coolers. The integration of passive and active technologies will form a hybrid system optimized to minimize the launch mass while preserving the cryogenic propellants. Since cryogenic propellants are the largest mass that Mars missions must launch from earth, even a modest reduction in the percentage of propellant carried results in a significant weight saving. This paper will present a brief overview of cryogenic fluid management

  6. Electromechanical actuation for cryogenic valve control

    NASA Technical Reports Server (NTRS)

    Lister, M. J.; Reichmuth, D. M.

    1993-01-01

    The design and analysis of the electromechanical actuator (EMA) being developed for the NASA/Marshall Space Flight Center as part of the National Launch System (NLS) Propellant Control Effector Advanced Development Program (ADP) are addressed. The EMA design uses several proven technologies combined into a single modular package which includes single stage high ratio gear reduction, redundant electric motors mounted on a common drive shaft, redundant drive and control electronics, and digital technology for performing the closed loop position feedback, communication, and health monitoring functions. Results of tests aimed at evaluating both component characteristics and overall system performance demonstrated that the goal of low cost, reliable control in a cryogenic environment is feasible.

  7. Strained silicon FETs on thin SiGe virtual substrates produced by He implantation: effect of reduced self-heating on DC and RF performance

    NASA Astrophysics Data System (ADS)

    Hackbarth, T.; Herzog, H.-J.; Hieber, K.-H.; König, U.; Mantl, S.; Holländer, B.; Lenk, St.; von Känel, H.; Enciso, M.; Aniel, F.; Giguerre, L.

    2004-11-01

    Strained-Si based SiGe MODFETs on ultra-thin SiGe virtual substrates prepared by molecular beam epitaxy (MBE) and helium implantation are presented and compared to similar devices on thick, compositionally graded virtual substrates grown by low energy plasma enhanced CVD (LEPECVD). MBE grown 100 nm thick pseudomorphic Si 0.67Ge 0.33 layers have been relaxed to about 70% by using He + ions implanted with a dose of 2 × 10 16 cm -2 at an energy of 18 keV approximately 100 nm below the hetero-interface, followed by an annealing step at 850 °C for 600 s. Then another Si 0.67Ge 0.33 layer and a modulation doped strained Si QW are grown on top of the virtual substrate having a final degree of relaxation of about 80%. A cut-off frequency of fmax(MAG)=121 GHz was achieved with RF devices having a gate length of 70 nm. Self-heating effects in devices on thick, graded, and on thin buffer layers are addressed by experimental DC and RF data and 2-D numerical simulations of the device temperature.

  8. Enhanced thermoelectric performance driven by high-temperature phase transition in the phase change material Ge4SbTe5

    DOE PAGES

    Williams, Jared B.; Lara-Curzio, Edgar; Cakmak, Ercan; ...

    2015-05-15

    Phase change materials are identified for their ability to rapidly alternate between amorphous and crystalline phases and have large contrast in the optical/electrical properties of the respective phases. The materials are primarily used in memory storage applications, but recently they have also been identified as potential thermoelectric materials. Many of the phase change materials researched today can be found on the pseudo-binary (GeTe)1-x(Sb2Te3)x tie-line. While many compounds on this tie-line have been recognized as thermoelectric materials, here we focus on Ge4SbTe5, a single phase compound just off of the (GeTe)1-x(Sb2Te3)x tie-line, that forms in a stable rocksalt crystal structure atmore » room temperature. We find that stoichiometric and undoped Ge4SbTe5 exhibits a thermal conductivity of ~1.2 W/m-K at high temperature and a large Seebeck coefficient of ~250 μV/K. The resistivity decreases dramatically at 623 K due to a structural phase transition which lends to a large enhancement in both thermoelectric power factor and thermoelectric figure of merit at 823 K. In a more general sense the research presents evidence that phase change materials can potentially provide a new route to highly efficient thermoelectric materials for power generation at high temperature.« less

  9. Tuning superior solar cell performance of carrier mobility and absorption in perovskite CH3NH3GeCl3: A density functional calculations

    NASA Astrophysics Data System (ADS)

    Zhao, Yu-Qing; Wu, Li-Juan; Liu, Biao; Wang, Ling-Zhi; He, Peng-Bin; Cai, Meng-Qiu

    2016-05-01

    The solar cell based on hybrid organic-inorganic halide perovskite has received considerable attention. One of the most important issues in the pursuit of further developments in this area is to obtain both a high carrier mobility and an excellent ability of light adsorption. In this paper, we investigate the electronic structure and electronic effective masses of the new non-toxic material CH3NH3GeCl3 by first-principle calculations. The results show that the absorption efficiency of CH3NH3GeCl3 is more superior to that of CH3NH3PbI3 in short wavelength region. We trace this result to the ferroelectricity caused by the more serious octahedral GeCl6- distortion. We also discover a new relationship between the carrier effective masses anisotropy and the anisotropy of electronic density of states along three principal directions. Moreover, while applied the isotropic compressive pressure, the absorption efficiency and carrier mobility of CH3NH3GeCl3 in orthorhombic phase are improved greatly due to changes of electronic structure. We speculate that these are general results of tuning of the carrier mobility by controlling the band gap and the electronic occupation along different directions, to obtain both a high carrier mobility and an excellent ability of light adsorption.

  10. Nanogel Aerogel as Load Bearing Insulation for Cryogenic Systems

    NASA Astrophysics Data System (ADS)

    Koravos, J. J.; Miller, T. M.; Fesmire, J. E.; Coffman, B. E.

    2010-04-01

    Load support structures in cryogenic storage, transport and processing systems are large contributors to the total heat leak of the system. Conventional insulation systems require the use of these support members in order to stabilize the process fluid enclosure and prevent degradation of insulation performance due to compression. Removal of these support structures would substantially improve system efficiency. Nanogel aerogel insulation performance is tested at vacuum pressures ranging from high vacuum to atmospheric pressure and under loads from loosely packed to greater than 10,000 Pa. Insulation performance is determined using boil-off calorimetry with liquid nitrogen as the latent heat recipient. Two properties of the aerogel insulation material suit it to act as a load bearing "structure" in a process vessel: (1) Ability to maintain thermal performance under load; (2) Elasticity when subjected to load. Results of testing provide positive preliminary indication that these properties allow Nanogel aerogel to effectively be used as a load bearing insulation in cryogenic systems.

  11. Development of a Flat-plate Cryogenic Oscillating Heat Pipe for Improving HTS Magnet Cooling

    NASA Astrophysics Data System (ADS)

    Natsume, K.; Mito, T.; Yanagi, N.; Tamura, H.

    A new method of including cryogenic oscillating heat pipes (OHPs) in the HTS coil windings as a thermal transport device has been studied. In this work, two type of OHPs are tested in low temperature. Employed working fluids are H2, Ne, N2. We have attained high performance thermal property using a bent-pipe cryogenic OHP as a prototype. Obtained effective conductivities have reached to 46000 W/m K. Then a flat-plate cryogenic OHP has been developed, that is suitable for imbedding in magnet windings. Preliminary experiments have been conducted and the result has been promising.

  12. Shuttle cryogenic supply system optimization study. Volume 3: Technical report, section 10, 11 and 12

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The evaluation of candidate cryogenic fuel systems for space shuttle vehicles is discussed. A set of guidelines was used to establish a matrix of possible combinations for the integration of potential cryogenic systems. The various concepts and combinations which resulted from the integration efforts are described. The parameters which were considered in developing the matrix are: (1) storage of cryogenic materials, (2) fuel lines, (3) tank pressure control, (4) thermal control, (5) fluid control, and (6) fluid conditioning. Block diagrams and drawings of the candidate systems are provided. Performance predictions for the systems are outlined in tables of data.

  13. An FPGA-based instrumentation platform for use at deep cryogenic temperatures

    SciTech Connect

    Conway Lamb, I. D.; Colless, J. I.; Hornibrook, J. M.; Pauka, S. J.; Waddy, S. J.; Reilly, D. J.; Frechtling, M. K.

    2016-01-15

    We describe the operation of a cryogenic instrumentation platform incorporating commercially available field-programmable gate arrays (FPGAs). The functionality of the FPGAs at temperatures approaching 4 K enables signal routing, multiplexing, and complex digital signal processing in close proximity to cooled devices or detectors within the cryostat. The performance of the FPGAs in a cryogenic environment is evaluated, including clock speed, error rates, and power consumption. Although constructed for the purpose of controlling and reading out quantum computing devices with low latency, the instrument is generic enough to be of broad use in a range of cryogenic applications.

  14. An FPGA-based instrumentation platform for use at deep cryogenic temperatures.

    PubMed

    Conway Lamb, I D; Colless, J I; Hornibrook, J M; Pauka, S J; Waddy, S J; Frechtling, M K; Reilly, D J

    2016-01-01

    We describe the operation of a cryogenic instrumentation platform incorporating commercially available field-programmable gate arrays (FPGAs). The functionality of the FPGAs at temperatures approaching 4 K enables signal routing, multiplexing, and complex digital signal processing in close proximity to cooled devices or detectors within the cryostat. The performance of the FPGAs in a cryogenic environment is evaluated, including clock speed, error rates, and power consumption. Although constructed for the purpose of controlling and reading out quantum computing devices with low latency, the instrument is generic enough to be of broad use in a range of cryogenic applications.

  15. POLOCAM: a millimeter wavelength cryogenic polarimeter prototype for MUSIC-POL

    NASA Astrophysics Data System (ADS)

    Laurent, Glenn T.; Vaillancourt, John E.; Savini, Giorgio; Ade, Peter A. R.; Beland, Stephane; Glenn, Jason; Hollister, Matthew I.; Maloney, Philip R.; Sayers, Jack

    2012-09-01

    As a proof-of-concept, we have constructed and tested a cryogenic polarimeter in the laboratory as a prototype for the MUSIC instrument (Multiwavelength Sub/millimeter Kinetic Inductance Camera). The POLOCAM instrument consists of a rotating cryogenic polarization modulator (sapphire half-waveplate) and polarization analyzer (lithographed copper polarizers deposited on a thin film) placed into the optical path at the Lyot stop (4K cold pupil stop) in a cryogenic dewar. We present an overview of the project, design and performance results of the POLOCAM instrument (including polarization efficiencies and instrumental polarization), as well as future application to the MUSIC-POL instrument.

  16. Advanced cryogenic tank development status

    NASA Astrophysics Data System (ADS)

    Braun, G. F.; Tack, W. T.; Scholz, E. F.

    1993-06-01

    Significant advances have been made in the development of materials, structures, and manufacturing technologies for the next generation of cryogenic propellant tanks under the auspices of a joint U.S. Air Force/NASA sponsored advanced development program. This paper summarizes the achievements of this three-year program, particularly in the evolution and properties of Weldalite 049, net shape component technology, Al-Li welding technology, and efficient manufacturing concepts. Results of a recent mechanical property characterization of a full-scale integrally stiffened barrel panel extrusion are presented, as well as plans for an additional weld process optimization program using response surface design of experiment techniques. A further discussion is given to the status of hardware completed for the Advanced Manufacturing Development Center and Martin Marietta's commitment to the integration of these technologies into the production of low-cost, light-weight cryogenic propellant tanks.

  17. The Cryogenic Dark Matter Search

    NASA Astrophysics Data System (ADS)

    Sander, Joel

    2004-05-01

    The Cryogenic Dark Matter Search (CDMS) is an experiment to search for Weakly Interacting Massive Particles (WIMPs). The experiment initially was deployed at a shallow underground site, and is currently deployed at a deep underground site at the Soudan Mine in Minnesota. The detectors operate at cryogenic temperature, and are capable of distinguishing nuclear recoils from WIMP interactions from various backgrounds. The detectors are shielded from background by both active and passive elements. We will describe the components of the overall experiment, and focus on the novel data acquisition system that has been develop to control and monitor the experiment via the World Wide Web. Preliminary signals from the operation at Soudan will be discussed.

  18. Cryogenic High-Sensitivity Magnetometer

    NASA Technical Reports Server (NTRS)

    Day, Peter; Chui, Talso; Goodstein, David

    2005-01-01

    A proposed magnetometer for use in a cryogenic environment would be sensitive enough to measure a magnetic-flux density as small as a picogauss (10(exp -16) Tesla). In contrast, a typical conventional flux-gate magnetometer cannot measure a magnetic-flux density smaller that about 1 microgauss (10(exp -10) Tesla). One version of this device, for operation near the low end of the cryogenic temperature range, would include a piece of a paramagnetic material on a platform, the temperature of which would be controlled with a periodic variation. The variation in temperature would be measured by use of a conventional germanium resistance thermometer. A superconducting coil would be wound around the paramagnetic material and coupled to a superconducting quantum interference device (SQUID) magnetometer.

  19. Insulating Cryogenic Pipes With Frost

    NASA Technical Reports Server (NTRS)

    Stephenson, J. G.; Bova, J. A.

    1985-01-01

    Crystallized water vapor fills voids in pipe insulation. Small, carefully controlled amount of water vapor introduced into dry nitrogen gas before it enters aft fuselage. Vapor freezes on pipes, filling cracks in insulation. Ice prevents gaseous nitrogen from condensing on pipes and dripping on structure, in addition to helping to insulate all parts. Industrial applications include large refrigeration plants or facilities that use cryogenic liquids.

  20. Cryogenic moderator simulations : confronting reality.

    SciTech Connect

    Iverson, E. B.

    1999-01-06

    The Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory is a spallation neutron source dedicated to materials research. Its three cryogenic methane moderators provide twelve neutron beams to fourteen instruments and test facilities. This report concerns ongoing activities for benchmarking our Monte Carlo model of the IPNS neutron generation system. This paper concentrates on the techniques (both experimental and calculational) used in such benchmarking activities.

  1. First-principles Study of the NiGe/Ge Schottky Barrier Height under Dopant Segregation

    NASA Astrophysics Data System (ADS)

    Lin, Chiung-Yuan; Lin, Han-Chi

    2015-03-01

    Traditional Si-based MOSFETs are approaching its fundamental scaling limits, and Ge has been comprehensively explored as a potential channel material to replace Si due to its high intrinsic carrier mobility for further performance enhancement. Nevertheless, strong Fermi-level pinning near the valence band edge of Ge leads to high electron Schottky barrier height. Dopant segregation technique has been proposed to achieve shallower junction depth and heavier dopant concentration for NiGe/Ge. However, the role of dopants at the NiGe/Ge interface is not clear. In this study, first-principles calculations are employed to nail down the most stable dopant position and to obtain the physical Schottky barrier height (by HSE06 hybrid functional) of the NiGe/Ge contact. For the conventional n-type dopant such as phosphorous and arsenic, our calculations show that those two elements may be segregated at the interface, while the reduction of the Schottky barrier height is insignificant. This implies that the experimental improvement of the NiGe/n-type Ge junction by dopant are mainly attributed to the increased dopant concentration around the interface. The authors acknowledge financial support from the Taiwan Ministry of Science and Technology (under Grant No. MOST 103-2112-M-009-004-).

  2. A pressure control analysis of cryogenic storage systems

    NASA Technical Reports Server (NTRS)

    Lin, C.-S.; Vandresar, N. T.; Hasan, M. M.

    1991-01-01

    Self-pressurization of cryogenic storage tanks due to heat leak through the thermal protection system is examined along with the performance of various pressure control technologies for application in microgravity environments. Methods of pressure control such as fluid mixing, passive thermodynamic venting, and active thermodynamic venting are analyzed using the homogeneous thermodynamic model. Simplified equations suggested may be used to characterize the performance of various pressure control systems and to design space experiments.

  3. Shuttle cryogenic supply system optimization study. Volume 4: Cryogenic cooling in environmental control systems

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An analysis of cryogenic fluid cooling in the environmental control system of the space shuttle was conducted. The technique for treating the cryogenic fluid storage and supply tanks and subsystems as integrated systems was developed. It was concluded that a basic incompatibility exists between the heat generated and the cryogen usage rate and cryogens cannot be used to absorb the generated heat. The use of radiators and accumulators to provide additional cooling capability is recommended.

  4. Cryogenic fluid management in space

    NASA Technical Reports Server (NTRS)

    Antar, Basil N.

    1988-01-01

    Many future space based vehicles and satellites will require on orbit refuelling procedures. Cryogenic fluid management technology is being developed to assess the requirements of such procedures as well as to aid in the design and development of these vehicles. Cryogenic fluid management technology for this application could be divided into two areas of study, one is concerned with fluid transfer process and the other with cryogenic liquid storage. This division is based upon the needed technology for the development of each area. In the first, the interaction of fluid dynamics with thermodynamics is essential, while in the second only thermodynamic analyses are sufficient to define the problem. The following specific process related to the liquid transfer area are discussed: tank chilldown and fill; tank pressurization; liquid positioning; and slosh dynamics and control. These specific issues are discussed in relation with the required technology for their development in the low gravity application area. In each process the relevant physics controlling the technology is identified and methods for resolving some of the basic questions are discussed.

  5. COLD-SAT: A technology satellite for cryogenic experimentation

    NASA Technical Reports Server (NTRS)

    Arif, H.; Kroeger, E. W.

    1989-01-01

    NASA-Lewis (LeRC) is involved in the development and validation of analytical models which describe the fluid dynamic and thermodynamic processes associated with the storage, acquisition and transfer of subcritical cryogenic fluids in low gravity. Four concurrent studies, including one in-house at LeRC, are underway to determine the feasibility of performing model validation experiments aboard a free-flying spacecraft (S/C) called Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT), using liquid hydrogen as the cryogen. The technology requirements for the experiments are described along with the initial LeRC concepts for the S/C and an experiment subsystem comprising of cryogenic tankage (a supply dewar and three receiver tanks), gas pressurization bottles (both helium and autogenous hydrogen), their associated plumbing, and instrumentation for data collection. Experiments were categorized into enabling/high priority Class 1 technologies and component/system Class 2 demonstrations. As initially envisioned by LeRC, COLD-SAT would have had a 1997 launch aboard a Delta-2 for a 6 month active lifetime in a 925 km orbit with a pseudo-inertial attitude.

  6. Facesheet Delamination of Composite Sandwich Materials at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Odegard, Gregory M.; Herring, Helen M.

    2003-01-01

    The next generation of space transportation vehicles will require advances in lightweight structural materials and related design concepts to meet the increased demands on performance. One potential source for significant structural weight reduction is the replacement of traditional metallic cryogenic fuel tanks with new designs for polymeric matrix composite tanks. These new tank designs may take the form of thin-walled sandwich constructed with lightweight core and composite facesheets. Life-time durability requirements imply the materials must safely carry pressure loads, external structural loads, resist leakage and operate over an extremely wide temperature range. Aside from catastrophic events like tank wall penetration, one of the most likely scenarios for failure of a tank wall of sandwich construction is the permeation of cryogenic fluid into the sandwich core and the subsequent delamination of the sandwich facesheet due to the build-up of excessive internal pressure. The research presented in this paper was undertaken to help understand this specific problem of core to facesheet delamination in cryogenic environments and relate this data to basic mechanical properties. The experimental results presented herein provide data on the strain energy release rate (toughness) of the interface between the facesheet and the core of a composite sandwich subjected to simulated internal pressure. A unique test apparatus and associated test methods are described and the results are presented to highlight the effects of cryogenic temperature on the measured material properties.

  7. First experimental data of the cryogenic safety test facility PICARD

    NASA Astrophysics Data System (ADS)

    Heidt, C.; Henriques, A.; Stamm, M.; Grohmann, S.

    2017-02-01

    The test facility PICARD, which stands for Pressure Increase in Cryostats and Analysis of Relief Devices, has been designed and constructed for cryogenic safety experiments. With a cryogenic liquid volume of 100 L, a nominal design pressure of 16 bar(g) and the capacity of measuring helium mass flow rates through safety relief devices up to 4 kg/s, the test facility allows the systematic investigation of hazardous incidents in cryostats under realistic conditions. In the course of experiments, the insulating vacuum is vented with atmospheric air or gaseous nitrogen at ambient temperature under variation of the venting diameter, the thermal insulation, the cryogenic fluid, the liquid level and the set pressure in order to analyze the impact on the heat flux and hence on the process dynamics. A special focus will be on the occurrence and implications of two-phase flow during expansion and on measuring the flow coefficients of safety devices at cryogenic temperatures. This paper describes the commissioning and the general performance of the test facility at liquid helium temperatures. Furthermore, the results of first venting experiments are presented.

  8. Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

    NASA Astrophysics Data System (ADS)

    Joshi, D. M.; Patel, H. K.

    2015-10-01

    Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

  9. Prediction of cryogenic heat pipe performance

    NASA Technical Reports Server (NTRS)

    Colwell, G. T.

    1976-01-01

    A 304 stainless steel heat pipe with slab type capillary structure and nitrogen as the working fluid was studied in the temperature range of 60 K to 120 K. The pipe was 1.27 cm in outside diameter and 9.14 cm in total length. In the transient studies, described in detail in this report, saddles were included at evaporator and condenser ends and a radiator was included at the condenser end.

  10. Effects of Cryogenic Temperatures on Spacecraft Internal Dielectric Discharges

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale c.; Schneider, Todd A.; Vaughn, Jason A.

    2009-01-01

    Abstract Most calculations of internal dielectric charging on spacecraft use tabulated values of material surface and bulk conductivities, dielectric constants, and dielectric breakdown strengths. Many of these properties are functions of temperature, and the temperature dependences are not well known. At cryogenic temperatures, where it is well known that material conductivities decrease dramatically, it is an open question as to the timescales over which buried charge will dissipate and prevent the eventual potentially disastrous discharges of dielectrics. In this paper, measurements of dielectric charging and discharging for cable insulation materials at cryogenic temperatures (approx. 90 K) are presented using a broad spectrum electron source at the NASA Marshall Space Flight Center. The measurements were performed for the James Webb Space Telescope (JWST), which will orbit at the Earth-Sun L2 point, and parts of which will be perennially at temperatures as low as 40 K. Results of these measurements seem to show that Radiation Induced Conductivity (RIC) under cryogenic conditions at L2 will not be sufficient to allow charges to bleed off of some typical cable insulation materials even over the projected JWST lifetime of a dozen years or more. After the charging and discharging measurements are presented, comparisons are made between the material conductivities that can be inferred from the measured discharges and conductivities calculated from widely used formulae. Furthermore, the measurement-inferred conductivities are compared with extrapolations of recent measurements of materials RIC and dark conductivities performed with the charge-storage method at Utah State University. Implications of the present measurements are also given for other spacecraft that may operate at cryogenic temperatures, such as probes of the outer planets or the permanently dark cratered areas on the moon. The present results will also be of interest to those who must design or

  11. Properties of cryogenically worked metals. [stainless steels

    NASA Technical Reports Server (NTRS)

    Schwartzberg, F. R.; Kiefer, T. F.

    1975-01-01

    A program was conducted to determine whether the mechanical properties of cryogenically worked 17-7PH stainless steel are suitable for service from ambient to cryogenic temperatures. It was determined that the stress corrosion resistance of the cryo-worked material is quite adequate for structural service. The tensile properties and fracture toughness at room temperature were comparable to titanium alloy 6Al-4V. However, at cryogenic temperatures, the properties were not sufficient to recommend consideration for structural service.

  12. The dependency of different stress-level SiN capping films and the optimization of D-SMT process for the device performance booster in Ge n-FinFETs

    SciTech Connect

    Liao, M.-H. Chen, P.-G.

    2015-08-17

    The capping stressed SiN film is one of the most important process steps for the dislocation stress memorization technique (D-SMT), which has been used widely in the current industry, for the electron mobility booster in the n-type transistor beyond the 32/28 nm technology node. In this work, we found that the different stress-level SiN capping films influence the crystal re-growth velocities along different directions including [100] and [110] directions in Ge a lot. It can be further used to optimize the dislocation angle in the transistor during the D-SMT process and then results in the largest channel stress distribution to boost the device performance in the Ge n-FinFETs. Based on the theoretical calculation and experimental demonstration, it shows that the Ge three dimensional (3D) n-FinFETs device performance is improved ∼55% with the usage of +3 GPa tensile stressed SiN capping film. The channel stress and dislocation angle is ∼2.5 GPa and 30°, measured by the atomic force microscope-Raman technique and transmission electron microscopy, respectively.

  13. Final report for the cryogenic retrieval demonstration

    SciTech Connect

    Valentich, D.J.; Yokuda, E.L.

    1992-09-01

    This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft[sup 3] of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a cold test pit'' that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 [times] 9 [times] 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub's proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.

  14. Final report for the cryogenic retrieval demonstration

    SciTech Connect

    Valentich, D.J.; Yokuda, E.L.

    1992-09-01

    This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft{sup 3} of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a ``cold test pit`` that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 {times} 9 {times} 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub`s proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.

  15. The Nuclear Cryogenic Propulsion Stage

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Kim, Tony; Emrich, William J.; Hickman, Robert R.; Broadway, Jeramie W.; Gerrish, Harold P.; Belvin, Anthony D.; Borowski, Stanley K.; Scott, John H.

    2014-01-01

    Nuclear Thermal Propulsion (NTP) development efforts in the United States have demonstrated the technical viability and performance potential of NTP systems. For example, Project Rover (1955 - 1973) completed 22 high power rocket reactor tests. Peak performances included operating at an average hydrogen exhaust temperature of 2550 K and a peak fuel power density of 5200 MW/m3 (Pewee test), operating at a thrust of 930 kN (Phoebus-2A test), and operating for 62.7 minutes in a single burn (NRX-A6 test). Results from Project Rover indicated that an NTP system with a high thrust-to-weight ratio and a specific impulse greater than 900 s would be feasible. Excellent results were also obtained by the former Soviet Union. Although historical programs had promising results, many factors would affect the development of a 21st century nuclear thermal rocket (NTR). Test facilities built in the US during Project Rover no longer exist. However, advances in analytical techniques, the ability to utilize or adapt existing facilities and infrastructure, and the ability to develop a limited number of new test facilities may enable affordable development, qualification, and utilization of a Nuclear Cryogenic Propulsion Stage (NCPS). Bead-loaded graphite fuel was utilized throughout the Rover/NERVA program, and coated graphite composite fuel (tested in the Nuclear Furnace) and cermet fuel both show potential for even higher performance than that demonstrated in the Rover/NERVA engine tests.. NASA's NCPS project was initiated in October, 2011, with the goal of assessing the affordability and viability of an NCPS. FY 2014 activities are focused on fabrication and test (non-nuclear) of both coated graphite composite fuel elements and cermet fuel elements. Additional activities include developing a pre-conceptual design of the NCPS stage and evaluating affordable strategies for NCPS development, qualification, and utilization. NCPS stage designs are focused on supporting human Mars

  16. Cryogenic Technology Development for Exploration Missions

    NASA Technical Reports Server (NTRS)

    Chato, David J.

    2007-01-01

    This paper reports the status and findings of different cryogenic technology research projects in support of the President s Vision for Space Exploration. The exploration systems architecture study is reviewed for cryogenic fluid management needs. It is shown that the exploration architecture is reliant on the cryogenic propellants of liquid hydrogen, liquid oxygen and liquid methane. Needs identified include: the key technologies of liquid acquisition devices, passive thermal and pressure control, low gravity mass gauging, prototype pressure vessel demonstration, active thermal control; as well as feed system testing, and Cryogenic Fluid Management integrated system demonstration. Then five NASA technology projects are reviewed to show how these needs are being addressed by technology research. Projects reviewed include: In-Space Cryogenic Propellant Depot; Experimentation for the Maturation of Deep Space Cryogenic Refueling Technology; Cryogenic Propellant Operations Demonstrator; Zero Boil-Off Technology Experiment; and Propulsion and Cryogenic Advanced Development. Advances are found in the areas of liquid acquisition of liquid oxygen, mass gauging of liquid oxygen via radio frequency techniques, computational modeling of thermal and pressure control, broad area cooling thermal control strategies, flight experiments for resolving low gravity issues of cryogenic fluid management. Promising results are also seen for Joule-Thomson pressure control devices in liquid oxygen and liquid methane and liquid acquisition of methane, although these findings are still preliminary.

  17. Cryogenics at the European Spallation Source

    NASA Astrophysics Data System (ADS)

    Weisend, J. G., II; Arnold, P.; Hees, J. Fydrych. W.; Jurns, J. M.; Wang, X. L.

    Cryogenics plays an important role at the European Spallation Source, a world class neutron science center, currently under construction in Lund, Sweden. Three principal applications of cryogenics are found at ESS. The SRF cryomodules of the ESS proton linac require cooling at 2 K, 4.5 K and 40 K; the hydrogenmoderator surrounding the target that produces neutrons, requires cooling via 16.5 K helium and LHe is required for many of the scientific instruments. These needs will be met by a set of three cryogenic refrigeration/liquefaction plants and an extensive cryogenic distribution system. Significant progress has been made on the ESS cryogenic system in preparation for the expected first beam on target in 2019. This work includes: funding of industry studies for the accelerator cryoplant, preliminary design of the cryogenic distribution system, investigation of possible in kind contributors and release of the invitation to tender for the accelerator cryoplant.This paper describes the requirements, design solutions and current status of the ESS cryogenic system. The planned recovery of waste heat from the cryogenic plants, a unique aspect of ESS, is described. The procurement of the cryogenic system, expected to be done via a combination of purchase via competitive bids and in kind contributions is also discussed.

  18. First Results from the Cryogenic Dark Matter Search Experiment at the Deep Site

    SciTech Connect

    Mandic, Vuk

    2004-06-01

    The Cryogenic Dark Matter Search (CDMS) experiment is designed to search for dark matter in the form of the Weakly Interacting Massive Particles (WIMPs). For this purpose, CDMS uses detectors based on crystals of Ge and Si, operated at the temperature of 20 mK, and providing a two-fold signature of an interaction: the ionization and the athermal phonon signals. The two signals, along with the passive and active shielding of the experimental setup, and with the underground experimental sites, allow very effective suppression and rejection of different types of backgrounds. This dissertation presents the commissioning and the results of the first WIMP-search run performed by the CDMS collaboration at the deep underground site at the Soudan mine in Minnesota. We develop different methods of suppressing the dominant background due to the electron-recoil events taking place at the detector surface and we apply these algorithms to the data set. These results place the world's most sensitive limits on the WIMP-nucleon spin-independent elastic-scattering cross-section. Finally, they examine the compatibility of the supersymmetric WIMP-models with the direct-detection experiments (such as CDMS) and discuss the implications of the new CDMS result on these models.

  19. Cryogenic detectors for dark matter search and neutrinoless double beta decay

    NASA Astrophysics Data System (ADS)

    Münster, Andrea; Schönert, Stefan; Willers, Michael

    2017-02-01

    The search for the neutrinoless double beta decay and the direct search for dark matter particles are amongst the most fundamental questions in astroparticle physics and cosmology. To achieve a high sensitivity, detectors with an excellent energy resolution and highly efficient particle identification capabilities are required. In recent years, cryogenic particle detectors have become one of the driving technologies in these fields. Future direct dark matter search experiments aim to improve the sensitivity for low mass dark matter particles (≲ 10 GeV /c2) down to the neutrino floor and the next generation of neutrinoless double beta decay experiments aims to improve the sensitivity on the half-life to ∼1026 -1027 years, corresponding to the parameter space predicted for the inverted mass ordering and degenerate mass range. To achieve these goals, significant improvements in detector performance and in radiopurity are required and both classes of experiments can benefit from the strong synergies in the fields of detector development and in the production of high purity single-crystals.

  20. Shuttle cryogenic supply system optimization study. Volume 5A-1: Users manual for math models

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The Integrated Math Model for Cryogenic Systems is a flexible, broadly applicable systems parametric analysis tool. The program will effectively accommodate systems of considerable complexity involving large numbers of performance dependent variables such as are found in the individual and integrated cryogen systems. Basically, the program logic structure pursues an orderly progression path through any given system in much the same fashion as is employed for manual systems analysis. The system configuration schematic is converted to an alpha-numeric formatted configuration data table input starting with the cryogen consumer and identifying all components, such as lines, fittings, and valves, each in its proper order and ending with the cryogen supply source assembly. Then, for each of the constituent component assemblies, such as gas generators, turbo machinery, heat exchangers, and accumulators, the performance requirements are assembled in input data tabulations. Systems operating constraints and duty cycle definitions are further added as input data coded to the configuration operating sequence.

  1. Performance Validation of Refrigeration Recovery for Experimental Hall High Target Loads

    SciTech Connect

    Errol Yuksek, Venkatarao, Ganni,Robert Norton, Peter Knudsen

    2012-07-01

    The Qweak experiment at Jefferson Lab (JLab) is a 3000 W hydrogen target scheduled to run until the planned shutdown in the spring of 2012 for the 12 GeV installation. As detailed in previous proceedings, support of this target's cryogenic load was made possible by incorporating modifications to the End Station Refrigerator (ESR) to recover the refrigeration supplied by the Central Helium Liquefier (CHL). Testing and commissioning for these modifications was performed in January and February 2010 demonstrating that the performance met or exceeded projected expectations. In this paper, we present the analysis of the test results in regards to the actual loads capable of being supported and the process boundaries encountered, as well as a discussion of the commissioning results for the cryogenic support of the Qweak target.

  2. GeMini: The Next-Generation Mechanically-Cooled Germanium Spectrometer

    SciTech Connect

    Burks, M

    2008-11-12

    The next-generation mechanically-cooled germanium spectrometer has been developed. GeMini (MINIature GErmanium spectrometer) has been designed to bring high-resolution gamma-ray spectroscopy to a range of demanding field environments. Intended applications include short-notice inspections, border patrol, port monitoring and emergency response, where positive nuclide identification of radioactive materials is required but power and liquid cryogen are not easily available. GeMini weighs 2.75 kg for the basic instrument and 4.5 kg for the full instrument including user interface and ruggedized hermetic packaging. It is very low power allowing it to operate for 10 hours on a single set of rechargeable batteries. This instrument employs technology adapted from the gamma-ray spectrometer currently flying on NASA's Mercury MESSENGER spacecraft. Specifically, infrared shielding techniques allow for a vast reduction of thermal load. This in turn allows for a smaller, lighter-weight design, well-suited for a hand-held instrument. Three working prototypes have been built and tested in the lab. The measured energy resolution is 3 keV fwhm at 662 keV gamma-rays. This paper will focus on the design and performance of the instrument.

  3. Nuclear Cryogenic Propulsion Stage for Mars Exploration

    NASA Technical Reports Server (NTRS)

    Houts, M. G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP).

  4. Versatile three-dimensional cryogenic micropositioning device

    NASA Astrophysics Data System (ADS)

    Heil, J.; Böhm, A.; Primke, M.; Wyder, P.

    1996-01-01

    A simple design for a mechanically driven three-dimensional cryogenic micropositioner is presented. The design is based on a parallelogram structure constructed from leaf springs and wires. Actuation is achieved by the elastic deformation of the parallelogram by screws. Positions within a volume of roughly (2 mm)3 are attainable. The precision and reproducibility of positioning are in the μm-range. The deviations from linearity are smaller than 10% for the whole working range and the deviation from orthogonality is smaller than 3°. Calibration measurements performed on a Cu-mesh with a lattice constant of 60 μm are presented. In an experiment investigating the ballistic transport of carriers in the semimetal Bi, two such devices are used. The first one is used as a scanning unit for an optical fiber and the second one is used as micropositioner for a Cu point contact.

  5. Cryogenics with cement microscopy redefines cement behavior

    SciTech Connect

    Mehta, S.; Jones, R. ); Caveny, B. )

    1994-10-03

    Cement microscopy (CM), cryogenics, environmental scanning microscopy (ESM), scanning electron microscopy (SEM), and other technologies are leading investigators to change their views on cement gelation, hydration, and retardation. Cement samples frozen in a nitrogen slush and viewed with an SEM present a more accurate picture of the setting process. Observations made through this technique have revolutionized ARCO Exploration and Production Technology's and Halliburton Energy Services' oil field cement procurement and slurry design. Findings from this joint study are expected to lead to: optimized waiting on cement (WOC) times; reduced planning and design time; optimized slurry retarder additions; optimized gel times to fit given situations; especially applicable to squeeze operations; improved cement selection (from vendors) for peak performance; and improved cement manufacture. The paper discusses the measuring methods and the findings on the following: cement voids, cement gelation, and retardation mechanisms. It also briefly discusses the impact these discoveries have on operations.

  6. Cryogenic Fluid Film Bearing Tester Development Study

    NASA Technical Reports Server (NTRS)

    Scharrer, Joseph K. (Editor); Murphy, Brian T.; Hawkins, Lawrence A.

    1993-01-01

    Conceptual designs were developed for the determination of rotordynamic coefficients of cryogenic fluid film bearings. The designs encompassed the use of magnetic and conventional excitation sources as well as the use of magnetic bearings as support bearings. Test article configurations reviewed included overhung, floating housing, and fixed housing. Uncertainty and forced response analyses were performed to assess quality of data and suitability of each for testing a variety of fluid film bearing designs. Development cost and schedule estimates were developed for each design. Facility requirements were reviewed and compared with existing MSFC capability. The recommended configuration consisted of a fixed test article housing centrally located between two magnetic bearings. The magnetic bearings would also serve as the excitation source.

  7. Cryogenic glass-filament-wound tank evaluation

    NASA Technical Reports Server (NTRS)

    Morris, E. E.; Landes, R. E.

    1971-01-01

    High-pressure glass-filament-wound fluid storage vessels with thin aluminum liners were designed, fabricated, and tested at ambient and cryogenic temperatures which demonstrated the feasibility of producing such vessels as well as high performance and light weight. Significant developments and advancements were made in solving problems associated with the thin metal liners in the tanks, including liner bonding to the overwrap and high strain magnification at the vessel polar bosses. The vessels had very high burst strengths, and failed in cyclic fatigue tests by local liner fracture and leakage without structural failure of the composite tank wall. The weight of the tanks was only 40 to 55% of comparable 2219-T87 aluminum and Inconel 718 tanks.

  8. Pratt and Whitney cryogenic turbopump bearing experience

    NASA Technical Reports Server (NTRS)

    Poole, W. E.; Bursey, R. W., Jr.

    1988-01-01

    Successful, reusable bearings require lubrication, traditionally, a transfer film from sacrificial cage wear. Early testing included materials screening programs to identify suitable cryogenic cage materials. A specially developed element tester that simulated the function of a ball bearing cage was used. Suitable materials must provide lubrication with an acceptably low wear rate, without abrading contacting surfaces. The most promising materials were tested in full scale bearings at speeds up to 4 MDN. Teflon, filled with 40 percent bronze powder, was the best performing material. A variety of bearings were designed and successfully tested in LH2 and LOX. Bearings with bronze filled Teflon cages were successfully tested for 150 hrs. In overload tests, the same design was tested for 5 hrs at maximum Hertz stresses above 450 ksi and an additional 5 hrs with a maximum Hertz stress exceeding 500 ksi. Four bearings were tested in LOX for 25 hrs, with a maximum time per bearing of 10 hrs.

  9. Shuttle cryogenic supply system optimization study. Volume 2: Technical report, sections 4 through 9

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The design and development of cryogenic supply systems for space shuttle vehicles are discussed. The weights, component counts, and statements of advantages and disadvantages of the systems considered are presented. Performance characteristics of the systems are analyzed in the form of graphs. Block diagrams and engineering drawings of the candidate systems are provided. Special consideration is given to flow rates and thermodynamic properties of the cryogenic systems.

  10. Enhanced thermoelectric performance driven by high-temperature phase transition in the phase change material Ge4SbTe5

    SciTech Connect

    Williams, Jared B.; Lara-Curzio, Edgar; Cakmak, Ercan; Watkins, Thomas R.; Morelli, Donald T.

    2015-05-15

    Phase change materials are identified for their ability to rapidly alternate between amorphous and crystalline phases and have large contrast in the optical/electrical properties of the respective phases. The materials are primarily used in memory storage applications, but recently they have also been identified as potential thermoelectric materials. Many of the phase change materials researched today can be found on the pseudo-binary (GeTe)1-x(Sb2Te3)x tie-line. While many compounds on this tie-line have been recognized as thermoelectric materials, here we focus on Ge4SbTe5, a single phase compound just off of the (GeTe)1-x(Sb2Te3)x tie-line, that forms in a stable rocksalt crystal structure at room temperature. We find that stoichiometric and undoped Ge4SbTe5 exhibits a thermal conductivity of ~1.2 W/m-K at high temperature and a large Seebeck coefficient of ~250 μV/K. The resistivity decreases dramatically at 623 K due to a structural phase transition which lends to a large enhancement in both thermoelectric power factor and thermoelectric figure of merit at 823 K. In a more general sense the research presents evidence that phase change materials can potentially provide a new route to highly efficient thermoelectric materials for power generation at high temperature.

  11. Carbon-Free Porous Zn2GeO4 Nanofibers as Advanced Anode Materials for High-Performance Lithium Ion Batteries.

    PubMed

    Li, Huan-Huan; Wu, Xing-Long; Zhang, Lin-Lin; Fan, Chao-Ying; Wang, Hai-Feng; Li, Xiao-Ying; Sun, Hai-Zhu; Zhang, Jing-Ping; Yan, Qingyu

    2016-11-23

    In this work, carbon-free, porous, and micro/nanostructural Zn2GeO4 nanofibers (p-ZGONFs) have been prepared via a dissolution-recrystallization-assisted electrospinning technology. The successful electrospinning to fabricate the uniform p-ZGONFs mainly benefits from the preparation of completely dissolved solution, which avoids the sedimentation of common Ge-containing solid-state precursors. Electrochemical tests demonstrate that the as-prepared p-ZGONFs exhibit superior Li-storage properties in terms of high initial reversible capacity of 1075.6 mA h g(-1), outstanding cycling stability (no capacity decay after 130 cycles at 0.2 A g(-1)), and excellent high-rate capabilities (e.g., still delivering a capacity of 384.7 mA h g(-1) at a very high current density of 10 A g(-1)) when used as anode materials for lithium ion batteries (LIBs). All these Li-storage properties are much better than those of Zn2GeO4 nanorods prepared by a hydrothermal process. The much enhanced Li-storage properties should be attributed to its distinctive structural characteristics including the carbon-free composition, plentiful pores, and macro/nanostructures. Carbon-free composition promises its high theoretical Li-storage capacity, and plentiful pores cannot only accommodate the volumetric variations during the successive lithiation/delithiation but can also serve as the electrolyte reservoirs to facilitate Li interaction with electrode materials.

  12. Cryogenic Fracturing: Laboratory Visualization Experiments and Numerical Simulations Using Peridynamics

    NASA Astrophysics Data System (ADS)

    Martin-Short, R.; Edmiston, J. K.

    2015-12-01

    Typical hydraulic fracturing operations involve the use of a large quantity of water, which can be problematic for several reasons including possible formation (permeability) damage, disposal of waste water, and the use of precious local water resource. An alternate reservoir permeability enhancing technology not requiring water is cryogenic fracturing. This method induces controlled fracturing of rock formations by thermal shock and has potentially important applications in the geothermal and hydrocarbon industries. In this process, cryogenic fluid—such as liquid nitrogen—is injected into the subsurface, causing fracturing due to thermal gradients. These fractures may improve the formation permeability relative to that achievable by hydraulic fracturing alone. We conducted combined laboratory visualization and numerical simulations studies of thermal-shock-induced fracture initiation and propagation resulting from liquid nitrogen injection in rock and analog materials. The experiment used transparent soda-lime glass cubes to facilitate real-time visualization of fracture growth and the fracture network geometry. In this contribution, we report the effect of overall temperature difference between cryogenic fluid and solid material on the produced fracture network, by pre-heating the glass cubes to several temperatures and injecting liquid nitrogen. Temperatures are monitored at several points by thermocouple and the fracture evolution is captured visually by camera. The experiment was modeled using a customized, thermoelastic, fracture-capable numerical simulation code based on peridynamics. The performance of the numerical code was validated by the results of the laboratory experiments, and then the code was used to study the different factors affecting a cryogenic fracturing operation, including the evolution of residual stresses and constitutive relationships for material failure. In complex rock such as shale, understanding the process of cryogenic

  13. Cryogenic actuator testing for the SAFARI ground calibration setup

    NASA Astrophysics Data System (ADS)

    de Jonge, C.; Eggens, M.; Nieuwenhuizen, A. C. T.; Detrain, A.; Smit, H.; Dieleman, P.

    2012-09-01

    For the on-ground calibration setup of the SAFARI instrument cryogenic mechanisms are being developed at SRON Netherlands Institute for Space Research, including a filter wheel, XYZ-scanner and a flipmirror mechanism. Due to the extremely low background radiation requirement of the SAFARI instrument, all of these mechanisms will have to perform their work at 4.5 Kelvin and low-dissipative cryogenic actuators are required to drive these mechanisms. In this paper, the performance of stepper motors, piezoelectric actuators and brushless DC-motors as cryogenic actuators are compared. We tested stepper motor mechanical performance and electrical dissipation at 4K. The actuator requirements, test setup and test results are presented. Furthermore, design considerations and early performance tests of the flipmirror mechanism are discussed. This flipmirror features a 102 x 72 mm aluminum mirror that can be rotated 45°. A Phytron stepper motor with reduction gearbox has been chosen to drive the flipmirror. Testing showed that this motor has a dissipation of 49mW at 4K with a torque of 60Nmm at 100rpm. Thermal modeling of the flipmirror mechanism predicts that with proper thermal strapping the peak temperature of the flipmirror after a single action will be within the background level requirements of the SAFARI instrument. Early tests confirm this result. For low-duty cycle operations commercial stepper motors appear suitable as actuators for test equipment in the SAFARI on ground calibration setup.

  14. Multidimensional Study of High-Adiabat OMEGA Cryogenic Experiments

    NASA Astrophysics Data System (ADS)

    Collins, T. J. B.; Betti, R.; Bose, A.; Christopherson, A. R.; Knauer, J. P.; Marozas, J. A.; Maximov, A. V.; Mora, A.; Radha, P. B.; Shang, W.; Shvydky, A.; Stoeckl, C.; Woo, K. M.; Varchas, G.

    2016-10-01

    Despite recent advances in modeling laser direct-drive inertial confinement fusion (ICF) experiments, there remains a predictability gap. This is particularly shown by the shortfall in hot-spot pressures inferred from OMEGA cryogenic implosions. To address this, a series of high-adiabat, cryogenic implosions were performed on OMEGA. These shots were performed with and without single-beam smoothing by spectral dispersion, at low and high drive intensities. These shots represent a regime where good agreement with simulation is expected because of the high adiabat. Multidimensional simulations of these shots will be presented with an emphasis on comparison with experimental indicators of departure from spherical symmetry (``1-D-ness''). The roles of short- and long-wavelength perturbations are considered. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  15. Cryogenic fluid management program flight concept definition

    NASA Technical Reports Server (NTRS)

    Kroeger, Erich

    1987-01-01

    The Lewis Research Center's cryogenic fluid management program flight concept definition is presented in viewgraph form. Diagrams are given of the cryogenic fluid management subpallet and its configuration with the Delta launch vehicle. Information is given in outline form on feasibility studies, requirements definition, and flight experiments design.

  16. Foam vessel for cryogenic fluid storage

    DOEpatents

    Spear, Jonathan D

    2011-07-05

    Cryogenic storage and separator vessels made of polyolefin foams are disclosed, as are methods of storing and separating cryogenic fluids and fluid mixtures using these vessels. In one embodiment, the polyolefin foams may be cross-linked, closed-cell polyethylene foams with a density of from about 2 pounds per cubic foot to a density of about 4 pounds per cubic foot.

  17. Continuous-Reading Cryogen Level Sensor

    NASA Technical Reports Server (NTRS)

    Barone, F. E.; Fox, E.; Macumber, S.

    1984-01-01

    Two pressure transducers used in system for measuring amount of cryogenic liquid in tank. System provides continuous measurements accurate within 0.03 percent. Sensors determine pressure in liquid and vapor in tank. Microprocessor uses pressure difference to compute mass of cryogenic liquid in tank. New system allows continuous sensing; unaffected by localized variations in composition and density as are capacitance-sensing schemes.

  18. Low Mn alloy steel for cryogenic service

    DOEpatents

    Morris, J.W. Jr.; Niikura, M.

    A ferritic cryogenic steel which has a relatively low (about 4 to 6%) manganese content and which has been made suitable for use at cryogenic temperatures by a thermal cycling treatment followed by a final tempering. The steel includes 4 to 6% manganese, 0.02 to 0.06% carbon, 0.1 to 0.4% molybdenum and 0 to 3% nickel.

  19. Cryogenic Boil-Off Reduction System Testing

    NASA Technical Reports Server (NTRS)

    Plachta, David W.; Johnson, Wesley L.; Feller, Jeffery

    2014-01-01

    The Cryogenic Boil-Off Reduction System was tested with LH2 and LOX in a vacuum chamber to simulate space vacuum and the temperatures of low Earth orbit. Testing was successful and results validated the scaling study model that predicts active cooling reduces upper stage cryogenic propulsion mass for loiter periods greater than 2 weeks.

  20. Neutron Detection with Cryogenics and Semiconductors

    SciTech Connect

    bell, Z.W.; Carpenter, D.A.; Cristy, S.S.; Lamberti, V.E.

    2005-03-10

    The common methods of neutron detection are reviewed with special attention paid to the application of cryogenics and semiconductors to the problem. The authors' work with LiF- and boron-based cryogenic instruments is described as well as the use of CdTe and HgI{sub 2} for direct detection of neutrons.