Science.gov

Sample records for 3-mm-diameter spot cryogen

  1. 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.

  2. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium tritium implosions on OMEGA

    SciTech Connect

    Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Yu. Glebov, V.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; Kessler, T. J.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; Maximov, A. V.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Nora, R.; Radha, P. B.; Regan, S. P.; Seka, W.; Shmayda, W. T.; Short, R.W.; Shvydky, A.; Skupsky, S.; Stoeckl, C.; Yaakobi, B.; Frenje, J. A.; Gatu-Johnson, M.; Petrasso, R. D.; Casey, D. T.

    2014-05-01

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≅ 4, an implosion velocity of 3.8 × 10⁷ cm/s, and a laser intensity of ~10¹⁵ W/cm². These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  3. Improving the hot-spot pressure and demonstrating ignition hydrodynamic equivalence in cryogenic deuterium–tritium implosions on OMEGA

    SciTech Connect

    Goncharov, V. N.; Sangster, T. C.; Betti, R.; Boehly, T. R.; Bonino, M. J.; Collins, T. J. B.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Follett, R. K.; Forrest, C. J.; Froula, D. H.; Glebov, V. Yu.; Harding, D. R.; Henchen, R. J.; Hu, S. X.; Igumenshchev, I. V.; Janezic, R.; Kelly, J. H.; and others

    2014-05-15

    Reaching ignition in direct-drive (DD) inertial confinement fusion implosions requires achieving central pressures in excess of 100 Gbar. The OMEGA laser system [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] is used to study the physics of implosions that are hydrodynamically equivalent to the ignition designs on the National Ignition Facility (NIF) [J. A. Paisner et al., Laser Focus World 30, 75 (1994)]. It is shown that the highest hot-spot pressures (up to 40 Gbar) are achieved in target designs with a fuel adiabat of α ≃ 4, an implosion velocity of 3.8 × 10{sup 7} cm/s, and a laser intensity of ∼10{sup 15} W/cm{sup 2}. These moderate-adiabat implosions are well understood using two-dimensional hydrocode simulations. The performance of lower-adiabat implosions is significantly degraded relative to code predictions, a common feature between DD implosions on OMEGA and indirect-drive cryogenic implosions on the NIF. Simplified theoretical models are developed to gain physical understanding of the implosion dynamics that dictate the target performance. These models indicate that degradations in the shell density and integrity (caused by hydrodynamic instabilities during the target acceleration) coupled with hydrodynamics at stagnation are the main failure mechanisms in low-adiabat designs. To demonstrate ignition hydrodynamic equivalence in cryogenic implosions on OMEGA, the target-design robustness to hydrodynamic instability growth must be improved by reducing laser-coupling losses caused by cross beam energy transfer.

  4. Demonstration of 55 +/- 7-Gbar Hot-Spot Pressure in Direct-Drive Layered DT Cryogenic Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Regan, S. P.

    2015-11-01

    Direct-drive ignition target designs for the National Ignition Facility (NIF) require hot-spot pressures in excess of 100 Gbar. Only one-third of the required pressure was inferred in earlier experimental campaigns conducted on the 60-beam, 30-kJ, 351-nm OMEGA laser with direct-drive implosions of layered DT cryogenic targets. Laser and target improvements were implemented on OMEGA to increase the stagnation pressure, including a set of phase plates to increase the laser irradiation uniformity on target and a purified fuel with isotope composition reaching a 50:50 DT ratio. Diagnostic improvements were made for a neutron burnwidth measurement with a 40-ps impulse response and a 16-channel Kirkpatrick-Baez microscope to measure gated (30-ps) x-ray images of the core near peak compression with 6- μm resolution. The inferred volume-averaged, peak pressure in the current campaign almost doubled to 55 +/- 7 Gbar with a neutron yield approaching 5 ×1013 . Further target performance improvements to reach hydrodynamic equivalence to ignition on OMEGA require mitigation of cross-beam energy transfer (CBET), which reduces the laser coupling. A proposed technique to reduce CBET by driving the spherical target with overlapping laser beams having individual focal spots smaller than the outside diameter of the target was investigated. The diameter of the target was discretely varied from 800 to 1000 μm, while the laser focal spot size was kept constant at 820 μm. The larger targets driven with up to 30 kJ of laser energy used dynamic bandwidth reduction, where the smoothing by spectral dispersion (SSD) is only applied to the pickets. The smaller targets driven with 26 kJ of laser energy had SSD on the entire pulse. This talk will summarize the results of this CBET mitigation campaign and describe a path forward to achieve ignition hydro-equivalence on OMEGA. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under

  5. Pulling of 3 mm diameter AlSb rods by micro-pulling down method

    SciTech Connect

    Bourret-Courchesne Ph.D., Edith; Perrodin, Didier

    2009-05-14

    We designed and supplied special crucibles for AlSb material. Thermal insulation and limitation of Sb losses were our first work. The protection of the growth environment was also one of our priority to avoid any pollution of the Fibercryst {mu}PD facility. When this work was achieved, the next step was the calibration of the heating power for these new crucibles. Then, it was the definition of single crystal growth conditions that oriented our research. Following our proposal, many growths attempts were performed. We started from Al & Sb pure powder or from LBNL AlSb crystal as expected. We used different crucibles and different seeds.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. Archived Guthrie blood spots as a novel source for quantitative DNA methylation analysis.

    PubMed

    Wong, Nicholas; Morley, Ruth; Saffery, Richard; Craig, Jeffrey

    2008-10-01

    Sodium bisulfite treatment followed by PCR and DNA sequencing is widely considered the gold standard for the analysis of DNA methylation patterns. However, this technique generally requires substantial quantities of genomic DNA as starting material and is often associated with degradation of DNA. Here, we assess the feasibility of performing bisulfite sequencing on DNA isolated from 3-mm diameter punches of dried blood Guthrie spots. We demonstrate that it is possible to perform bisulfite sequencing from both freshly prepared and archived dried blood spots, using a combination of high purity DNA extraction and efficient bisulfite conversion. With the number of new technologies available for DNA methylation studies, we have extended this analysis and have successfully used a high-throughput mass spectrometry method for DNA methylation analysis on these samples. This provides a new source of material for epigenetic analysis of birth samples and provides an invaluable reference point to track temporal change in epigenetic profiles possibly linked with health and disease.

  15. Liver spots

    MedlinePlus

    Sun-induced skin changes - liver spots; Senile or solar lentigines; Skin spots - aging; Age spots ... Liver spots are changes in skin color that occur in older skin. The coloring may be due to aging, exposure to the sun or other sources of ...

  16. 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)

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Vibrio sp. causing Porites ulcerative white spot disease.

    PubMed

    Arboleda, Mark D M; Reichardt, Wolfgang T

    2010-06-11

    The causative agent of the Indo-Pacific coral disease, Porites ulcerative white spot syndrome (PUWS), that affects Porites spp. and a few other coral genera has so far remained unidentified. Inoculation of thiosulphate citrate bile sucrose (TCBS) agar with tissue material from Porites cylindrica infected with white spot produced colonies of approximately 3 mm diameter consisting of Gram-negative, motile, non-sucrose-fermenting, slightly curved rods with a minimum NaCl requirement of 0.3%. Three of these putative Vibrio sp. isolates were used for infection trials that included different stages of cell growth. Four modes of inoculation and 3 stages of bacterial cell growth were considered for testing Koch's postulates. Stationary phase cells proved more consistently infectious than did exponentially growing or starved cells using a 1-step immersion technique at cell concentrations of 10(4) cells ml(-1). A 1-step immersion technique proved more reliable in producing signs of white spot than did other techniques, such as injection, smearing and 2-step immersion of the inoculum. At inoculum densities >10(4) cells ml(-1) further signs of disease, such as tissue degradation and bleaching, also became evident. At elevated temperatures (>29 degrees C) bleaching remained absent for at least 2 mo from non-inoculated corals serving as controls, but was observed in artificially infected coral fragments. Of the 9 seawater aquaria containing healthy specimens of P. cylindrica, 6 showed signs of white spot 15 d after infection with an isolate tentatively identified as Vibrio sp. Based on 99% similarity of its 16S rRNA gene sequence and selected phenotypical features, this isolate revealed a close relationship to V. natriegens and V. parahaemolyticus.

  2. 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.

  3. 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.

  4. SPOT Program

    NASA Technical Reports Server (NTRS)

    Smith, Jason T.; Welsh, Sam J.; Farinetti, Antonio L.; Wegner, Tim; Blakeslee, James; Deboeck, Toni F.; Dyer, Daniel; Corley, Bryan M.; Ollivierre, Jarmaine; Kramer, Leonard; Zimmerman, Patrick L.; Khatri, Reshma

    2010-01-01

    A Spacecraft Position Optimal Tracking (SPOT) program was developed to process Global Positioning System (GPS) data, sent via telemetry from a spacecraft, to generate accurate navigation estimates of the vehicle position and velocity (state vector) using a Kalman filter. This program uses the GPS onboard receiver measurements to sequentially calculate the vehicle state vectors and provide this information to ground flight controllers. It is the first real-time ground-based shuttle navigation application using onboard sensors. The program is compact, portable, self-contained, and can run on a variety of UNIX or Linux computers. The program has a modular objec-toriented design that supports application-specific plugins such as data corruption remediation pre-processing and remote graphics display. The Kalman filter is extensible to additional sensor types or force models. The Kalman filter design is also strong against data dropouts because it uses physical models from state and covariance propagation in the absence of data. The design of this program separates the functionalities of SPOT into six different executable processes. This allows for the individual processes to be connected in an a la carte manner, making the feature set and executable complexity of SPOT adaptable to the needs of the user. Also, these processes need not be executed on the same workstation. This allows for communications between SPOT processes executing on the same Local Area Network (LAN). Thus, SPOT can be executed in a distributed sense with the capability for a team of flight controllers to efficiently share the same trajectory information currently being computed by the program. SPOT is used in the Mission Control Center (MCC) for Space Shuttle Program (SSP) and International Space Station Program (ISSP) operations, and can also be used as a post -flight analysis tool. It is primarily used for situational awareness, and for contingency situations.

  5. 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.

  6. Dark Spots

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Dark spots (left) and 'fans' appear to scribble dusty hieroglyphics on top of the Martian south polar cap in two high-resolution Mars Global Surveyor, Mars Orbiter Camera images taken in southern spring. Each image is about 3-kilometers wide (2-miles).

  7. 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.

  8. Defrosting Spots

    NASA Technical Reports Server (NTRS)

    2005-01-01

    3 October 2005 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows dark, defrosting spots formed on a polygon-cracked plain in the south polar region of Mars. The surface was covered with carbon dioxide frost during the previous winter. In spring, the material begins to sublime away, creating a pattern of dark spots that sometimes have wind streaks emanating from them, as wind carries away or erodes the frost.

    Location near: 87.2oS, 28.4oW Image width: width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Spring

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. Mongolian spots.

    PubMed

    Gupta, Divya; Thappa, Devinder Mohan

    2013-01-01

    Mongolian spots (MS) are birthmarks that are present at birth and their most common location is sacrococcygeal or lumbar area. Lesions may be single or multiple and usually involve < 5% total body surface area. They are macular and round, oval or irregular in shape. The color varies from blue to greenish, gray, black or a combination of any of the above. The size varies from few to more than 20 centimetres. Pigmentation is most intense at the age of one year and gradually fades thereafter. It is rarely seen after the age of 6 years. Aberrant MS over occiput, temple, mandibular area, shoulders and limbs may be confused with other dermal melanocytoses and bruises secondary to child abuse, thus necessitating documentation at birth. Although regarded as benign, recent data suggest that MS may be associated with inborn errors of metabolism and neurocristopathies. Mongolian spots usually resolve by early childhood and hence no treatment is generally needed if they are located in the sacral area. However, sometimes it may be required for extrasacral lesions for cosmesis.

  20. 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.

  1. 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.

  2. Laser-induced fluorescence of phosphors for remote cryogenic thermometry

    NASA Technical Reports Server (NTRS)

    Beshears, D. L.; Capps, G. J.; Cates, M. R.; Simmons, C. M.; Schwenterly, S. W.

    1990-01-01

    Remote cryogenic temperature measurements can be made by inducing fluorescence in phosphors with temperature-dependent emissions and measuring the emission lifetimes. The thermographic phosphor technique can be used for making precision, noncontact, cryogenic-temperature measurements in electrically hostile environments, such as high dc electric or magnetic fields. The National Aeronautics and Space Administration is interested in using these thermographic phosphors for mapping hot spots on cryogenic tank walls. Europium-doped lanthanum oxysulfide (La2O2S:Eu) and magnesium fluorogermanate doped with manganese (Mg4FGeO6:Mn) are suitable for low-temperature surface thermometry. Several emission lines, excited by a 337-nm ultraviolet laser, provide fluorescence lifetimes having logarithmic dependence with temperature from 4 to above 125 K. A calibration curve for both La2O2S:Eu and Mg4FGeO6:Mn is presented, as well as emission spectra taken at room temperature and 11 K.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Southern Spots

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site] Context image for PIA03092 Southern Spots

    This VIS image of the south polar region was collected during the summer season. The markings of the pole are very diverse and easy to see after the winter frost has been removed.

    Image information: VIS instrument. Latitude 79.7S, Longitude 56.6E. 17 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  10. 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.

  11. Are 'hot spots' hot spots?

    NASA Astrophysics Data System (ADS)

    Foulger, Gillian R.

    2012-07-01

    The term 'hot spot' emerged in the 1960s from speculations that Hawaii might have its origins in an unusually hot source region in the mantle. It subsequently became widely used to refer to volcanic regions considered to be anomalous in the then-new plate tectonic paradigm. It carried with it the implication that volcanism (a) is emplaced by a single, spatially restricted, mongenetic melt-delivery system, assumed to be a mantle plume, and (b) that the source is unusually hot. This model has tended to be assumed a priori to be correct. Nevertheless, there are many geological ways of testing it, and a great deal of work has recently been done to do so. Two fundamental problems challenge this work. First is the difficulty of deciding a 'normal' mantle temperature against which to compare estimates. This is usually taken to be the source temperature of mid-ocean ridge basalts (MORBs). However, Earth's surface conduction layer is ˜200 km thick, and such a norm is not appropriate if the lavas under investigation formed deeper than the 40-50 km source depth of MORB. Second, methods for estimating temperature suffer from ambiguity of interpretation with composition and partial melt, controversy regarding how they should be applied, lack of repeatability between studies using the same data, and insufficient precision to detect the 200-300 °C temperature variations postulated. Available methods include multiple seismological and petrological approaches, modelling bathymetry and topography, and measuring heat flow. Investigations have been carried out in many areas postulated to represent either (hot) plume heads or (hotter) tails. These include sections of the mid-ocean spreading ridge postulated to include ridge-centred plumes, the North Atlantic Igneous Province, Iceland, Hawaii, oceanic plateaus, and high-standing continental areas such as the Hoggar swell. Most volcanic regions that may reasonably be considered anomalous in the simple plate-tectonic paradigm have been

  12. 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.

  13. 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)

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Experimental investigation of bright spots in broadband, gated x-ray images of ignition-scale implosions on the National Ignition Facility

    SciTech Connect

    Barrios, M. A.; Suter, L. J.; Glenn, S.; Benedetti, L. R.; Bradley, D. K.; Collins, G. W.; Hammel, B. A.; Izumi, N.; Ma, T.; Scott, H.; Smalyuk, V. A.; Regan, S. P.; Epstein, R.; Kyrala, G. A.

    2013-07-15

    Bright spots in the hot spot intensity profile of gated x-ray images of ignition-scale implosions at the National Ignition Facility [G. H. Miller et al., Opt. Eng. 443, (2004)] are observed. X-ray images of cryogenically layered deuterium-tritium (DT) and tritium-hydrogen-deuterium (THD) ice capsules, and gas filled plastic shell capsules (Symcap) were recorded along the hohlraum symmetry axis. Heterogeneous mixing of ablator material and fuel into the hot spot (i.e., hot-spot mix) by hydrodynamic instabilities causes the bright spots. Hot-spot mix increases the radiative cooling of the hot spot. Fourier analysis of the x-ray images is used to quantify the evolution of bright spots in both x- and k-space. Bright spot images were azimuthally binned to characterize bright spot location relative to known isolated defects on the capsule surface. A strong correlation is observed between bright spot location and the fill tube for both Symcap and cryogenically layered DT and THD ice targets, indicating the fill tube is a significant seed for the ablation front instability causing hot-spot mix. The fill tube is the predominant seed for Symcaps, while other capsule non-uniformities are dominant seeds for the cryogenically layered DT and THD ice targets. A comparison of the bright spot power observed for Si- and Ge-doped ablator targets shows heterogeneous mix in Symcap targets is mostly material from the doped ablator layer.

  6. Mongolian blue spots (image)

    MedlinePlus

    Mongolian blue spots are flat bluish- to bluish-gray skin markings commonly appearing at birth or shortly ... back and also can appear on the shoulders. Mongolian spots are benign and are not associated with ...

  7. Rocky Mountain spotted fever

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000654.htm Rocky Mountain spotted fever To use the sharing features on this page, please enable JavaScript. Rocky Mountain spotted fever is a disease caused by a type of ...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  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. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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 .

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Cryogenic Storage Tank Non-Destructive Evaluation

    NASA Technical Reports Server (NTRS)

    Arens, Ellen

    2010-01-01

    This slide presentation reviews the work in non-destructive evaluation (NDE) of cryogenic storage tanks. Four large cryogenic tanks, constructed in 1965 with perlite insulation in the annular regions, are of concern. The construction of the tanks, two Liquid Oxygen (LOX) and two Liquid Hydrogen (LH2), are described. The loss rate for the LOX tank at Pad A is slightly higher than that for the one at Pad B. The concerns for the LH2 tank at Pad B are that there is a significantly higher boil-off rate than that at Pad A, that there is mold growth, indicative of increased heat flow, that there is a long down-time needed for repairs, and that 3 of 5 full thermal cycles have been used on the Pad B LH2 tank. The advantages and disadvantages of thermal imaging are given. A detailed description of what is visible of the structures in the infra-red is given and views of the thermal images are included. Missing Perlite is given as the probable cause of the cold spot on the Pad B LH2 tank. There is no indications of problematic cold regions on the Pad A LH2 tank, as shown by the thermal images given in the presentation. There is definite indication of a cold region on the Pad A LOX tank. There is however concerns with thermal imaging, as thermal images can be significantly effected by environmental conditions, image differences on similar days but with different wind speeds. Other effects that must be considered include ambient temperature, humidity levels/dew, and cloud reflections

  20. The Earth's Hot Spots.

    ERIC Educational Resources Information Center

    Vink, Gregory E.; And Others

    1985-01-01

    Hot spots are isolated areas of geologic activity where volcanic eruptions, earthquakes, and upwelling currents occur far from plate boundaries. These mantle plumes are relatively stable and crustal plates drift over them. The nature and location of hot spots (with particular attention to the Hawaiian Islands and Iceland) are discussed. (DH)

  1. 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.

  2. 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.

  3. Aural stealth of portable cryogenically cooled infrared imagers

    NASA Astrophysics Data System (ADS)

    Veprik, Alexander; Vilenchick, Herman; Broyde, Ramon; Pundak, Nachman

    2006-05-01

    Novel tactics for carrying out military and antiterrorist operations calls for the development of a new generation of portable infrared imagers, the focal plane arrays of which are maintained at a cryogenic temperature. The rotary Stirling cryogenic engines providing for this cooling are usually mounted directly upon the light thin-walled imager frame, which is used for optical alignment, mechanical stability and heat sinking. The known disadvantage of this design approach is that the wideband vibration export produced by the cooler results in structural resonances and therefore in excessive noise radiation from the above imagers. The "noisy" thermal imager may be detected from quite a long distance using acoustic equipment relying upon a high-sensitive unidirectional microphone or aurally spotted when used in a close proximity to the opponent force. As a result, aural stealth along with enhanced imagery, compact design, low power consumption and long life-times become a crucial figure of merit characterising the modern infrared imager. Achieving the desired inaudibility level is a challenging task. As a matter of fact, even the best examples of modern "should-be silent" infrared imagers are quite audible from as far as 50 meters away even when operating in a steady-state mode. The authors report on the successful effort of designing the inaudible at greater then 10 meters cryogenically cooled infrared imager complying with the stringent MIL-STD-1774D (Level II) requirements.

  4. 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.

  5. 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.

  6. Watermarking spot colors

    NASA Astrophysics Data System (ADS)

    Alattar, Osama M.; Reed, Alastair M.

    2003-06-01

    Watermarking of printed materials has usually focused on process inks of cyan, magenta, yellow and black (CMYK). In packaging, almost three out of four printed materials include spot colors. Spot colors are special premixed inks, which can be produced in a vibrant range of colors, often outside the CMYK color gamut. In embedding a watermark into printed material, a common approach is to modify the luminance value of each pixel in the image. In the case of process color work pieces, the luminance change can be scaled to the C, M, Y and K channels using a weighting function, to produce the desired change in luminance. In the case of spot color art designs, there is only one channel available and the luminance change is applied to this channel. In this paper we develop a weighting function to embed the watermark signal across the range of different spot colors. This weighting function normalizes visibility effect and signal robustness across a wide range of different spot colors. It normalizes the signal robustness level over the range of an individual spot color"s intensity levels. Further, it takes into account the sensitivity of the capturing device to the different spot colors.

  7. 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.

  8. 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).

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Mononucleosis spot test

    MedlinePlus

    Monospot test; Heterophile antibody test; Heterophile agglutination test; Paul-Bunnell test; Forssman antibody test ... The mononucleosis spot test is done when symptoms of mononucleosis are ... Fatigue Fever Large spleen (possibly) Sore throat Tender ...

  17. Lincoln's Spot Resolutions.

    ERIC Educational Resources Information Center

    Mueller, Jean West; Schamel, Wynell Burroughs

    1988-01-01

    Examines the events leading to and immediately following the declaration of war on Mexico in 1846. Includes the second and third pages of Abraham Lincoln's "Spot Resolutions" and presents teaching suggestions for interpreting the document and assessing public opinion. (GEA)

  18. SPOT4 Management Centre

    NASA Technical Reports Server (NTRS)

    Labrune, Yves; Labbe, X.; Roussel, A.; Vielcanet, P.

    1994-01-01

    In the context of the CNES SPOT4 program CISI is particularly responsible for the development of the SPOT4 Management Centre, part of the SPOT4 ground control system located at CNES Toulouse (France) designed to provide simultaneous control over two satellites. The main operational activities are timed to synchronize with satellite visibilities (ten usable passes per day). The automatic capability of this system is achieved through agenda services (sequence of operations as defined and planned by operator). Therefore, the SPOT4 Management Centre offers limited, efficient and secure human interventions for supervision and decision making. This paper emphasizes the main system characteristics as degree of automation, level of dependability and system parameterization.

  19. Scientists Spot 'Teetotaler' Gene

    MedlinePlus

    ... gov/news/fullstory_162265.html Scientists Spot 'Teetotaler' Gene Discovery might one day lead to drugs to ... HealthDay News) -- Scientists say they've identified a gene variant that dampens the desire to drink alcohol. ...

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. On-line liquid chromatography/tandem mass spectrometry simultaneous determination of opiates, cocainics and amphetamines in dried blood spots.

    PubMed

    Saussereau, E; Lacroix, C; Gaulier, J M; Goulle, J P

    2012-02-15

    A novel approach has been developed for the illicit drugs quantitative determination using dried blood spots (DBS) on filter paper. The illicit drugs tested were opiates (morphine and its 3- and 6-glucuronide metabolites, codeine, 6-monoacetylmorphine), cocainics (ecgonine methylester, benzoylecgonine, cocaine, cocaethylene) and amphetamines (amphetamine, methamphetamine, MDA, MDMA, MDEA). The described method, requiring a small blood volume, is based on high performance liquid chromatography coupled to tandem mass spectrometry using on-line extraction. A Whatman card 903 was spotted with 30μL of whole blood and left overnight to dry at room temperature. A 3-mm diameter disk was removed using a manual punch, suspended in 150μL of water for 10min with ultrasonication, and then 100μL was injected in the on-line LC-MS/MS system. An Oasis HLB was used as an extraction column and a C18 Atlantis as an analytical column. The chromatographic cycle was performed with 20mM ammonium formate buffer (pH 2.8) (solvent A) and acetonitrile/solvent A (90:10, v/v) gradient in 16min. Detection was performed in positive electrospray ionization mode (ESI+) with a Quattro Micro (Waters). Recoveries of all analytes were up to 80%. DBS were stored in duplicate at 4°C and -20°C for up to 6 months. Illicit drugs seemed to be much more stabled at -20°C. Furthermore, it was tested whether analysis of DBS may be as reliable as that of whole blood investigating authentic samples; significant correlations were obtained. This DBS assay has potential as rapid, sensitive and inexpensive option for the illicit drugs determination in small blood volumes, which seems of great interest in suspected cases of driving under the influence of drugs.

  11. 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

  12. IR Spot Weld Inspect

    SciTech Connect

    Chen, Jian; Feng, Zhili

    2014-01-01

    In automotive industry, destructive inspection of spot welds is still the mandatory quality assurance method due to the lack of efficient non-destructive evaluation (NDE) tools. However, it is costly and time-consuming. Recently at ORNL, a new NDE prototype system for spot weld inspection using infrared (IR) thermography has been developed to address this problem. This software contains all the key functions that ensure the NDE system to work properly: system input/output control, image acquisition, data analysis, weld quality database generation and weld quality prediction, etc.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Rolling Spot Welder

    NASA Technical Reports Server (NTRS)

    Wagner, Garret E.; Fonteyne, Steve L.

    1990-01-01

    Wheeled tool speeds tack-welding operations. Spotwelds foil to parts in preparation for brazing. Includes electrode wheel rolling across foil. Welding current in electrode pulsed as electrode moves along, making series of uniformly-spaced low-current spot welds.

  3. Bacterial leaf spot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot has been reported in Australia (Queensland), Egypt, El Salvador, India, Japan, Nicaragua, Sudan, and the United States (Florida, Iowa, Kansas, Maryland, and Wisconsin). It occasionally causes locally severe defoliation and post-emergence damping-off and stunting. The disease is...

  4. Rocky Mountain Spotted Fever.

    PubMed

    Phillips, Jennan

    2017-01-01

    The tick-borne disease Rocky Mountain spotted fever (RMSF) can have deadly outcomes unless treated appropriately, yet nonspecific flu-like symptoms complicate diagnosis. Occupational health nurses must have a high index of suspicion with symptomatic workers and recognize that recent recreational or occupational activities with potential tick exposure may suggest RMSF.

  5. Arc spot grouping: An entanglement of arc spot cells

    SciTech Connect

    Kajita, Shin; Hwangbo, Dogyun; Ohno, Noriyasu; Tsventoukh, Mikhail M.; Barengolts, Sergey A.

    2014-12-21

    In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that an entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  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. TV spots' impact.

    PubMed

    El-bakly, S

    1994-09-01

    The Information, Education and Communication (IEC) Center of the State Information Service was established in 1979 for the purpose of providing information to the people on the population issue. The Ministry of Information has accorded the State Information Service free TV and radio air time for family planning dramas and spots. In the early years information campaigns were organized to make people aware of the population problem by slogans, songs, and cartoons. Around 1984 misconceptions about family planning and contraceptives were attacked through a number of TV and radio spots. A few years later 21 spots on specific contraceptive methods were broadcast which were aired for three years over 3000 times. They were extremely successful. The impact of these TV spots was one of the major reasons why the contraceptive prevalence rate increased from 30% in 1984 to 38% in 1988 and 47% in 1992. Spots were also broadcast about the social implications of large families. The TV soap opera "And The Nile Flows On", with the family planning message interwoven into it, was very well received by the target audience. A program entitled "Wedding of the Month" features couples who know family planning well. The most successful radio program is a 15-20 minute long quiz show for residents of the villages where the Select Villages Project is being implemented. The State Information Service has 60 local information centers in the 26 governorates of Egypt that make plans for the family planning campaign. In 1992 the Minya Initiative, a family planning project was implemented in the Minya Governorate. As a result, the contraceptive prevalence rate rose from 22% to 30% over 18 months. A new project, the Select Village Project, was developed in 1993 that replicates the Minya Initiative on the village level in other governorates. This new project that was implemented in sixteen governorates.

  13. 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.

  14. 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.

  15. Flow visualization in a cryogenic wind tunnel using holography

    NASA Astrophysics Data System (ADS)

    Burner, A. W.; Goad, W. K.

    1982-11-01

    Results of holographic flow visualization from tests made in the Langley 0.3 meter transonic cryogenic tunnel are presented. The tunnel was operated over a temperature range from 100 to 300 K and a pressure range from 1.1 to 4 atm. Interferometry at the facility may be of limited use at the low temperature high pressure conditions because of the jumbled nature of the reference fringes. The shadowgraph technique appears to be the best means of visualizing shocks at these high density conditions. The spot size at the focus of the reconstructed beams was measured and used as an indicator of density fluctuations in the flow field. These density fluctuations appear to be caused by temperature fluctuations of the test gas which are relatively independent of tunnel conditions.

  16. Three-Dimensional Analysis of the Effects of Low-Mode Asymmetries on OMEGA Cryogenic Implosions

    NASA Astrophysics Data System (ADS)

    Anderson, K. S.; McKenty, P. W.; Shvydky, A.; Knauer, J. P.; Collins, T. J. B.; Marinak, M. M.

    2016-10-01

    Understanding the role of low-mode asymmetries is essential to characterizing inertial confinement fusion implosions. Asymmetries seeded by nonuniformities in laser drive, capsule manufacture, and target positioning lead to shell modulation as well as nonradial hydrodynamic flow in the hot spot at stagnation, which can adversely affect peak pressure and neutron yield. Full-sphere three-dimensional simulations are required to quantify the flow in the hot spot and its impact on hot-spot pressure and other observables. This paper will analyze results from HYDRA simulations of OMEGA cryogenic implosions modeling various sources of low-mode asymmetries (e.g., target offset, laser power imbalance, ice layer roughness) and show comparisons with experimental observables. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Numbers DE-NA0001944 and performed under the auspices of the LLNL under Contract No. DE-AC52-07NA27344.

  17. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    SciTech Connect

    Regan, S. P.; Epstein, R.; Hammel, B. A.; Suter, L. J.; Ralph, J.; Scott, H.; Barrios, M. A.; Bradley, D. K.; Callahan, D. A.; Cerjan, C.; Collins, G. W.; Dixit, S. N.; Doeppner, T.; Edwards, M. J.; Farley, D. R.; Glenn, S.; Glenzer, S. H.; Golovkin, I. E.; Haan, S. W.; Hamza, A.; Hicks, D. G.; Izumi, N.; Kilkenny, J. D.; Kline, J. L.; Kyrala, G. A.; Landen, O. L.; Ma, T.; MacFarlane, J. J.; Mancini, R. C.; McCrory, R. L.; Meezan, N. B.; Meyerhofer, D. D.; Nikroo, A.; Peterson, K. J.; Sangster, T. C.; Springer, P.; Town, R. P. J.

    2012-03-30

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraum x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.

  18. Hot-spot mix in ignition-scale implosions on the NIF [Hot-spot mix in ignition-scale implosions on the National Ignition Facility (NIF)

    DOE PAGES

    Regan, S. P.; Epstein, R.; Hammel, B. A.; ...

    2012-03-30

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding 2 a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraummore » x-ray drive. Richtmyer–Meshkov and Rayleigh–Taylor hydrodynamic instabilities seeded by high-mode (50 < t < 200) ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium–hydrogen–deuterium (THD) and DT cryogenic targets and gas-filled plastic shell capsules, which replace the THD layer with a massequivalent CH layer, was examined. The inferred amount of hot-spot mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code, is typically below the 75 ng allowance for hot-spot mix. Furthermore, predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.« less

  19. Low cost, SPF aluminum cryogenic tank structure for ALS

    NASA Technical Reports Server (NTRS)

    Anton, Claire E.; Rasmussen, Perry; Thompson, Curt; Latham, Richard; Hamilton, C. Howard; Ren, Ben; Gandhi, Chimata; Hardwick, Dallis

    1992-01-01

    Past production work has shown that cryogenic tank structure for the Shuttle Booster Rockets and the Titan system have very high life cycle costs for the fuel tank structure. The tanks are machined stiffener-skin combination that are subsequently formed into the required contour after machining. The material scrap rate for these configurations are usually high, and the loss of a tank panel due to forming or heat treatment problems is very costly. The idea of reducing the amount of scrap material and scrapped structural members has prompted the introduction of built-up structure for cryogenic tanks to be explored on the ALS program. A build-up structure approach that has shown improvements in life cycle cost over the conventional built-up approach is the use of superplastically formed (SPF) stiffened panels (reducing the overall part count and weight for the tank) resistance spot welded (RSW) to outer tank skin material. The stiffeners provide for general stability of the tank, while the skin material provides hoop direction continuity for the loads.

  20. Improved algorithm of ray tracing in ICF cryogenic targets

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Yang, Yongying; Ling, Tong; Jiang, Jiabin

    2016-10-01

    The high precision ray tracing inside inertial confinement fusion (ICF) cryogenic targets plays an important role in the reconstruction of the three-dimensional density distribution by algebraic reconstruction technique (ART) algorithm. The traditional Runge-Kutta methods, which is restricted by the precision of the grid division and the step size of ray tracing, cannot make an accurate calculation in the case of refractive index saltation. In this paper, we propose an improved algorithm of ray tracing based on the Runge-Kutta methods and Snell's law of refraction to achieve high tracing precision. On the boundary of refractive index, we apply Snell's law of refraction and contact point search algorithm to ensure accuracy of the simulation. Inside the cryogenic target, the combination of the Runge-Kutta methods and self-adaptive step algorithm are employed for computation. The original refractive index data, which is used to mesh the target, can be obtained by experimental measurement or priori refractive index distribution function. A finite differential method is performed to calculate the refractive index gradient of mesh nodes, and the distance weighted average interpolation methods is utilized to obtain refractive index and gradient of each point in space. In the simulation, we take ideal ICF target, Luneberg lens and Graded index rod as simulation model to calculate the spot diagram and wavefront map. Compared the simulation results to Zemax, it manifests that the improved algorithm of ray tracing based on the fourth-order Runge-Kutta methods and Snell's law of refraction exhibits high accuracy. The relative error of the spot diagram is 0.2%, and the peak-to-valley (PV) error and the root-mean-square (RMS) error of the wavefront map is less than λ/35 and λ/100, correspondingly.

  1. Poisson Spot with Magnetic Levitation

    ERIC Educational Resources Information Center

    Hoover, Matthew; Everhart, Michael; D'Arruda, Jose

    2010-01-01

    In this paper we describe a unique method for obtaining the famous Poisson spot without adding obstacles to the light path, which could interfere with the effect. A Poisson spot is the interference effect from parallel rays of light diffracting around a solid spherical object, creating a bright spot in the center of the shadow.

  2. Rocky Mountain spotted fever.

    PubMed

    Lacz, N L; Schwartz, R A; Kapila, R

    2006-04-01

    Rocky Mountain spotted fever (RMSF) is an unusual but important dermatological condition to identify without hesitation. The classic triad of headache, fever, and a rash that begins on the extremities and travels proximally to involve the trunk is found in a majority of patients. The cutaneous centripetal pattern is a result of cell to cell migration by the causative organism Rickettsia rickettsii. Such individuals should receive prompt antimicrobial therapy and supportive care to avoid serious and potentially fatal complications.

  3. Rocky Mountain spotted fever.

    PubMed

    Kamper, C A; Chessman, K H; Phelps, S J

    1988-02-01

    The epidemiology, pathogenesis, clinical features, and treatment of Rocky Mountain spotted fever are reviewed. Rocky Mountain spotted fever is a severe infection caused by Rickettsia rickettsii transmitted to man by various species of ticks. High-incidence areas exist in the southeast and south central United States. Only 60-70% of patients with the disease report a history of tick bite or exposure to tick-infested areas. The disease is initially characterized by fever, headache, gastrointestinal complaints, myalgia, and a generalized rash. In several days generalized vasculitis may lead to periorbital edema and nonpitting edema of the face and extremities. Central nervous system involvement is common. Because signs and symptoms associated with the disease are nonspecific, the diagnosis is often delayed or missed. Traditionally diagnostic confirmation relied on serologic testing, but an indirect fluorescent antibody assay will soon be commercially available. Rocky Mountain spotted fever is usually treated with the rickettsiostatic agents chloramphenicol or tetracycline, but few comparative data on these agents in patients with the disease are available. For patients who cannot tolerate oral medications, intravenous chloramphenicol sodium succinate is the preferred treatment; chloramphenicol is also the drug of choice for children less than eight years of age. Otherwise, oral tetracycline hydrochloride is the drug of choice. Antibiotic therapy should be continued for 7-10 days or until the patient is afebrile for two to five days. All cases of Rocky Mountain spotted fever must be reported to the Centers for Disease Control. The best ways to decrease the morbidity and mortality of the disease are to increase awareness of its signs and symptoms and to prevent exposure to ticks.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. CRESST cryogenic dark matter search

    NASA Astrophysics Data System (ADS)

    Cozzini, C.; Angloher, G.; Bucci, C.; Feilitzsch, F. von; Frank, T.; Hauff, D.; Henry, S.; Jagemann, T.; Jochum, J.; Kraus, H.; Majorovits, B.; Ninkovic, J.; Petricca, F.; Pröbst, F.; Ramachers, Y.; Rau, W.; Razeti, M.; Seidel, W.; Stark, M.; Stodolsky, L.; Uchaikin, S.; Wulandari, H.

    2005-05-01

    The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO 4 crystals as absorbers for direct WIMP (weakly interactive massive particles) detection. The phonon signal in the CaWO 4 crystal is registered in coincidence with the light signal, which is measured with a separate cryogenic light detector. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers (W-SPTs). As a result an active discrimination of the electron recoils against nuclear recoils is achieved. Results on the properties of the detector modules and on the WIMP sensitivity are presented.

  11. Residual contact restraints in cryogenics

    NASA Astrophysics Data System (ADS)

    Cretegny, J. F.; Demonicault, J. M.

    The use of residual stress measurements to evaluate the state of cryogenic turbomachines, whose surfaces are worn by the working conductions in dry contact, is addressed. Their contribution to the understanding of the reasons of possible ruptures is considered. It is stated that residual stress measurements should be used as a complementary tool rather than as input data for models. It is shown, thanks to two examples concerning the ball bearings and splines of the liquid hydrogen turbopump of the Vulcain engine, what can be expected from such techniques. Total exploitation of the results has still to be done, but preliminary results are quite encouraging.

  12. Fiberglass supports for cryogenic tanks

    NASA Technical Reports Server (NTRS)

    Keller, C. W.

    1972-01-01

    Analysis, design, fabrication, and test activities were conducted to develop additional technology needed for application of filament-wound fiberglass struts to cryogenic flight tankage. It was conclusively verified that monocoque cylinder or ogive struts are optimum or near-optimum for the range of lengths and loads studied, that a higher strength-to-weight ratio can be achieved for fiberglass struts than for any metallic struts, and that integrally-wrapped metallic end fittings can be used to achieve axial load transfer without reliance on bond strength or mechanical fasteners.

  13. The influence of cryogenic mass exchange on the distribution of viable microfauna in cryozems

    NASA Astrophysics Data System (ADS)

    Gubin, S. V.; Lupachev, A. V.; Shatilovich, A. V.; Myl'nikov, A. P.; Ryss, A. Yu.; Veremeeva, A. A.

    2016-12-01

    The role of cryogenic mass exchange in the distribution of the viable microfauna (ciliates, heterotrophic flagellates, and nematodes) in the profiles of cryoturbated cryogenic soils and in the upper layers of permafrost was revealed. The material for microbiological investigations was collected from the main horizons of cryozem profiles, including the zones with morphologically manifested processes of cryogenic mass exchange (the development of barren spots, cryoturbation, and suprapermafrost accumulation) and the zones affected by solifluction. The radiocarbon dating of the soil samples showed that the age of the organic cryogenic material and material buried in the course of solifluction varied from 2100 to 4500 years. Some zones with specific ecological conditions promoting the preservation of species diversity of the microfauna were found to develop in the cryozem profiles. A considerable part of the community (38% of ciliates, 58% of flagellates, and 50% of nematodes) maintained its viability in the dormant state, and in some cases, it could pass to the state of long-term cryobiosis in the upper layer of permafrost.

  14. Numerical simulations of cryogenic cavitating flows

    NASA Astrophysics Data System (ADS)

    Kim, Hyunji; Kim, Hyeongjun; Min, Daeho; Kim, Chongam

    2015-12-01

    The present study deals with a numerical method for cryogenic cavitating flows. Recently, we have developed an accurate and efficient baseline numerical scheme for all-speed water-gas two-phase flows. By extending such progress, we modify the numerical dissipations to be properly scaled so that it does not show any deficiencies in low Mach number regions. For dealing with cryogenic two-phase flows, previous EOS-dependent shock discontinuity sensing term is replaced with a newly designed EOS-free one. To validate the proposed numerical method, cryogenic cavitating flows around hydrofoil are computed and the pressure and temperature depression effect in cryogenic cavitation are demonstrated. Compared with Hord's experimental data, computed results are turned out to be satisfactory. Afterwards, numerical simulations of flow around KARI turbopump inducer in liquid rocket are carried out under various flow conditions with water and cryogenic fluids, and the difference in inducer flow physics depending on the working fluids are examined.

  15. Cryogenic Systems: Recent Trends and New Directions

    NASA Astrophysics Data System (ADS)

    Weisend, John

    2011-03-01

    The production of reliable cryogenic temperatures is vital for the use of superconductivity in accelerators. Cryogenics is found in the accelerating structures and magnets of the accelerator as well as in the magnets and calorimeters of the detectors in the experimental areas. In the century since the discovery of superconductivity, cryogenic systems have gone from small laboratory devices to very large industrial scale systems involving multiple refrigeration plants, containing over 100 tonnes of liquid helium. These systems, while specialized, represent a mature, well understood technology. This paper will survey the current status of cryogenic systems in accelerators and describe recent trends including: the large scale use of He II (superfluid helium) and the development of higher reliability and higher efficiency systems. It will also discuss future directions including the increased use of HiTc current leads, possible applications for small cryocoolers and the potential impact of the world helium supply on accelerator cryogenics.

  16. 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.

  17. Techniques for on-orbit cryogenic servicing

    NASA Astrophysics Data System (ADS)

    DeLee, C. H.; Barfknecht, P.; Breon, S.; Boyle, R.; DiPirro, M.; Francis, J.; Huynh, J.; Li, X.; McGuire, J.; Mustafi, S.; Tuttle, J.; Wegel, D.

    2014-11-01

    NASA (National Aeronautics and Space Administration) has a renewed interest in on-orbit cryogen storage and transfer to support its mission to explore near-earth objects such as asteroids and comets. The Cryogenic Propellant Storage and Transfer Technology Demonstration Mission (CPST-TDM), managed by the NASA Glenn Research Center (GRC) and scheduled for launch in 2018, will demonstrate numerous key technologies applicable to a cryopropellant fuel depot. As an adjunct to the CPST-TDM work, experiments at NASA Goddard Space Flight Center (GSFC) will support the development of techniques to manage and transfer cryogens on-orbit and expand these techniques as they may be applicable to servicing science missions using solid cryogens such as the Wide-field Infrared Survey Explorer (WISE). The results of several ground experiments are described, including autogenous pressurization used for transfer of liquid nitrogen and argon, characterization of the transfer and solidification of argon, and development of robotic tools for cryogen transfer.

  18. 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.

  19. Models for cryogenic wind tunnels

    NASA Technical Reports Server (NTRS)

    Lawing, Pierce L.

    1989-01-01

    Model requirements, types of model construction methods, and research in new ways to build models are discussed. The 0.3-m Transonic Cryogenic Tunnel was in operation for 16 years and many 2-D airfoil pressure models were tested. In addition there were airfoil models dedicated to transition detection techniques and other specialized research. There were also a number of small 3-D models tested. A chronological development in model building technique is described which led to the construction of many successful models. The difficulties of construction are illustrated by discussing several unsuccessful model fabrication attempts. The National Transonic Facility, a newer and much larger tunnel, was used to test a variety of models including a submarine, transport and fighter configurations, and the Shuttle Orbiter. A new method of building pressure models was developed and is described. The method is centered on the concept of bonding together plates with pressure channels etched into the bond planes, which provides high density pressure instrumentation with minimum demand on parent model material. With care in the choice of materials and technique, vacuum brazing can be used to produce strong bonds without blocking pressure channels and with no bonding voids between channels. Using multiple plates, a 5 percent wing with 96 orifices was constructed and tested in a transonic cryogenic wind tunnel. Samples of test data are presented and future applications of the technology are suggested.

  20. 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.

  1. 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.

  2. The cryogenic storage ring CSR

    NASA Astrophysics Data System (ADS)

    von Hahn, R.; Becker, A.; Berg, F.; Blaum, K.; Breitenfeldt, C.; Fadil, H.; Fellenberger, F.; Froese, M.; George, S.; Göck, J.; Grieser, M.; Grussie, F.; Guerin, E. A.; Heber, O.; Herwig, P.; Karthein, J.; Krantz, C.; Kreckel, H.; Lange, M.; Laux, F.; Lohmann, S.; Menk, S.; Meyer, C.; Mishra, P. M.; Novotný, O.; O'Connor, A. P.; Orlov, D. A.; Rappaport, M. L.; Repnow, R.; Saurabh, S.; Schippers, S.; Schröter, C. D.; Schwalm, D.; Schweikhard, L.; Sieber, T.; Shornikov, A.; Spruck, K.; Sunil Kumar, S.; Ullrich, J.; Urbain, X.; Vogel, S.; Wilhelm, P.; Wolf, A.; Zajfman, D.

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm-3 is derived, equivalent to a room-temperature pressure below 10-14 mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  3. The cryogenic storage ring CSR.

    PubMed

    von Hahn, R; Becker, A; Berg, F; Blaum, K; Breitenfeldt, C; Fadil, H; Fellenberger, F; Froese, M; George, S; Göck, J; Grieser, M; Grussie, F; Guerin, E A; Heber, O; Herwig, P; Karthein, J; Krantz, C; Kreckel, H; Lange, M; Laux, F; Lohmann, S; Menk, S; Meyer, C; Mishra, P M; Novotný, O; O'Connor, A P; Orlov, D A; Rappaport, M L; Repnow, R; Saurabh, S; Schippers, S; Schröter, C D; Schwalm, D; Schweikhard, L; Sieber, T; Shornikov, A; Spruck, K; Sunil Kumar, S; Ullrich, J; Urbain, X; Vogel, S; Wilhelm, P; Wolf, A; Zajfman, D

    2016-06-01

    An electrostatic cryogenic storage ring, CSR, for beams of anions and cations with up to 300 keV kinetic energy per unit charge has been designed, constructed, and put into operation. With a circumference of 35 m, the ion-beam vacuum chambers and all beam optics are in a cryostat and cooled by a closed-cycle liquid helium system. At temperatures as low as (5.5 ± 1) K inside the ring, storage time constants of several minutes up to almost an hour were observed for atomic and molecular, anion and cation beams at an energy of 60 keV. The ion-beam intensity, energy-dependent closed-orbit shifts (dispersion), and the focusing properties of the machine were studied by a system of capacitive pickups. The Schottky-noise spectrum of the stored ions revealed a broadening of the momentum distribution on a time scale of 1000 s. Photodetachment of stored anions was used in the beam lifetime measurements. The detachment rate by anion collisions with residual-gas molecules was found to be extremely low. A residual-gas density below 140 cm(-3) is derived, equivalent to a room-temperature pressure below 10(-14) mbar. Fast atomic, molecular, and cluster ion beams stored for long periods of time in a cryogenic environment will allow experiments on collision- and radiation-induced fragmentation processes of ions in known internal quantum states with merged and crossed photon and particle beams.

  4. Challenges for Cryogenics at Iter

    NASA Astrophysics Data System (ADS)

    Serio, L.

    2010-04-01

    Nuclear fusion of light nuclei is a promising option to provide clean, safe and cost competitive energy in the future. The ITER experimental reactor being designed by seven partners representing more than half of the world population will be assembled at Cadarache, South of France in the next decade. It is a thermonuclear fusion Tokamak that requires high magnetic fields to confine and stabilize the plasma. Cryogenic technology is extensively employed to achieve low-temperature conditions for the magnet and vacuum pumping systems. Efficient and reliable continuous operation shall be achieved despite unprecedented dynamic heat loads due to magnetic field variations and neutron production from the fusion reaction. Constraints and requirements of the largest superconducting Tokamak machine have been analyzed. Safety and technical risks have been initially assessed and proposals to mitigate the consequences analyzed. Industrial standards and components are being investigated to anticipate the requirements of reliable and efficient large scale energy production. After describing the basic features of ITER and its cryogenic system, we shall present the key design requirements, improvements, optimizations and challenges.

  5. Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF.

    PubMed

    Ma, T; Izumi, N; Tommasini, R; Bradley, D K; Bell, P; Cerjan, C J; Dixit, S; Döppner, T; Jones, O; Kline, J L; Kyrala, G; Landen, O L; LePape, S; Mackinnon, A J; Park, H-S; Patel, P K; Prasad, R R; Ralph, J; Regan, S P; Smalyuk, V A; Springer, P T; Suter, L; Town, R P J; Weber, S V; Glenzer, S H

    2012-10-01

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

  6. Red Spot Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This brief movie shows counterclockwise atmospheric motion around Jupiter's Great Red Spot. The clip was made from blue-filter images taken with the narrow-angle camera on NASA's Cassini spacecraft during seven separate rotations of Jupiter between Oct. 1 and Oct. 5, 2000.

    The clip also shows the eastward and westward motion of the zonal jets, seen as the horizontal stripes flowing in opposite directions. The zonal jets circle the planet. As far as can be determined from both Earth-based and spacecraft measurements, the positions and speeds of the jets have not changed for 100 years. Since Jupiter is a fluid planet without a solid boundary, the jet speeds are measured relative to Jupiter's magnetic field, which rotates, wobbling like a top because of its tilt, every 9 hours 55.5 minutes. The movie shows motions in the magnetic reference frame, so winds to the west correspond to features that are rotating a little slower than the magnetic field, and eastward winds correspond to features rotating a little faster.

    Because the Red Spot is in the southern hemisphere, the direction of motion indicates it is a high-pressure center. Small bright clouds appear suddenly to the west of the Great Red Spot. Scientists suspect these small white features are lightning storms. The storms eventually merge with the Red Spot and surrounding jets, and may be the main energy source for the large-scale features.

    The smallest features in the movie are about 500 kilometers (about 300 miles) across. The spacing of the movie frames in time is not uniform; some consecutive images are separated by two Jupiter rotations, and some by one. The images have been re-projected using a simple cylindrical map projection. They show an area from 50 degrees north of Jupiter's equator to 50 degrees south, extending 100 degrees east-west, about one quarter of Jupiter's circumference.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet

  7. [Rocky Mountain spotted fever].

    PubMed

    Reinauer, K M; Jaschonek, K; Kusch, G; Heizmann, W R; Döller, P C; Jenss, H

    1990-01-12

    After returning from a holiday in the USA a 24-year-old man fell ill with diarrhoea, high fever and marked rash including the palms of the hands and soles of the feet. When a history of a tick bite in the USA was elicited, a rickettsial infection was suspected. Treatment with doxycycline, 100 mg twice daily, was instituted finally and the fever slowly resolved. The patient became completely well again within four weeks. Serological tests confirmed the diagnosis of Rocky Mountain spotted fever.

  8. Dark Spots and Fans

    NASA Technical Reports Server (NTRS)

    2006-01-01

    As winter turns to spring at the south polar ice cap of Mars, the rising sun reveals dark spots and fans emerging from the cold polar night. Using visual images (left) and temperature data (right) from the Thermal Emission Imaging system on NASA's Mars Odyssey orbiter, scientists have built a new model for the origin of the dark markings. Scientists propose the markings come from dark sand and dust strewn by high-speed jets of carbon-dioxide gas. These erupt from under a layer of carbon-dioxide ice that forms each Martian winter.

  9. Imaging of High-Energy X-Ray Emission from Cryogenic Thermonuclear Fuel Implosions on the NIF

    SciTech Connect

    Ma, T

    2012-05-01

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered targets. Using bremsstrahlung assumptions, the measured absolute x-ray brightness allows for the inference of electron temperature, electron density, hot spot mass, mix mass, and pressure. Current inertial confinement fusion (ICF) experiments conducted on the National Ignition Facility (NIF) seek to indirectly drive a spherical implosion, compressing and igniting a deuterium-tritium fuel. This DT fuel capsule is cryogenically prepared as a solid ice layer surrounded by a low-Z ablator material. Ignition will occur when the hot spot approaches sufficient temperature ({approx}3-4 keV) and {rho}R ({approx}0.3 g/cm{sup 2}) such that alpha deposition can further heat the hot spot and generate a self-sustaining burn wave. During the implosion, the fuel mass becomes hot enough to emit large amounts of x-ray radiation, the spectra and spatial variation of which contains key information that can be used to evaluate the implosion performance. The Ross filter diagnostic employs differential filtering to provide spectrally resolved, time-integrated, absolute x-ray self-emission images of the imploded core of cryogenic layered targets.

  10. Configurable hot spot fixing system

    NASA Astrophysics Data System (ADS)

    Kajiwara, Masanari; Kobayashi, Sachiko; Mashita, Hiromitsu; Aburada, Ryota; Furuta, Nozomu; Kotani, Toshiya

    2014-03-01

    Hot spot fixing (HSF) method has been used to fix many hot spots automatically. However, conventional HSF based on a biasing based modification is difficult to fix many hot spots under a low-k1 lithography condition. In this paper we proposed a new HSF, called configurable hotspot fixing system. The HSF has two major concepts. One is a new function to utilize vacant space around a hot spot by adding new patterns or extending line end edges around the hot spot. The other is to evaluate many candidates at a time generated by the new functions. We confirmed the proposed HSF improves 73% on the number of fixing hot spots and reduces total fixing time by 50% on a device layout equivalent to 28nm-node. The result shows the proposed HSF is effective for layouts under the low-k1 lithography condition.

  11. Turbulent spots in hypervelocity flow

    NASA Astrophysics Data System (ADS)

    Jewell, Joseph S.; Leyva, Ivett A.; Shepherd, Joseph E.

    2017-04-01

    The turbulent spot propagation process in boundary layer flows of air, nitrogen, carbon dioxide, and air/carbon dioxide mixtures in thermochemical nonequilibrium at high enthalpy is investigated. Experiments are performed in a hypervelocity reflected shock tunnel with a 5-degree half-angle axisymmetric cone instrumented with flush-mounted fast-response coaxial thermocouples. Time-resolved and spatially demarcated heat transfer traces are used to track the propagation of turbulent bursts within the mean flow, and convection rates at approximately 91, 74, and 63% of the boundary layer edge velocity, respectively, are observed for the leading edge, peak, and trailing edge of the spots. A simple model constructed with these spot propagation parameters is used to infer spot generation rates from observed transition onset to completion distance. Spot generation rates in air and nitrogen are estimated to be approximately twice the spot generation rates in air/carbon dioxide mixtures.

  12. Jovian Dark Spot

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A recently discovered black spot in Jupiter's clouds is darker than any feature ever before observed on the giant planet. The spot may be the result of a downward spiraling wind that blows away high clouds and reveals deeper, very dark cloud layers. These three panels depict the same area of Jupiter's atmosphere. A map of Jovian temperatures near 250 millibar pressure (top) panel is derived from the photopolarimeter-radiometer instrument on NASA's Galileo Jupiter orbiter. This map is compared with maps derived from images of the same area in visible light (middle panel)and thermal radiation sensitive to cloud-top temperatures (bottom panel).

    The single downward-pointing arrow in the top panel indicates the location of a warm area that corresponds to the position of a so-called 'black spot'(shown in the middle panel), a feature that is about a year old. Features this dark are rare on Jupiter. The bottom panel, sensitive to temperatures at Jupiter's cloud tops, shows this feature as a bright object, meaning that upper-level cold clouds are missing - allowing us to see deeper into Jupiter's warmer interior. The dark visible appearance of the feature than most likely represents the color of very deep clouds. The warm temperatures and cloud-free conditions imply that this feature is a region where dry upper-atmospheric gas is being forced to converge, is warmed up and then forced to descend, clearing out clouds. It is the opposite of wet, upwelling gas in areas such as Jupiter's Great Red Spot or white ovals. On the other hand, it is unlike the dry and relatively cloudless feature into which the Galileo probe descended in 1995, because that region had the same temperatures as its surroundings and did not appear nearly as dark as this new spot.

    The temperatures sampled by the photopolarimeter radiometer are near the top of Jupiter's troposphere, where wind motions control the atmosphere. The top row of arrows shows the location of temperature waves in a warm region

  13. 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

  14. Cryogenic storage tank with a retrofitted in-tank cryogenic pump

    SciTech Connect

    Zwick, E.B.; Brigham, W.D.

    1989-08-29

    This patent describes a low boiloff submersible pump assembly for use in a conventional cryogenic tank having an open access port. It comprises: a pump; a removable pump mounting tube extending through the access port of the cryogenic tank. The pump mounting tube having an inner surface thermally insulated from an outer surface of the tube and thermally insulated from the access port of the cryogenic tank. The tube having an open lower end, the upper end of the tube including means adapted to make a gas-tight seal with the pump mounted thereto. The tube extending through the tank and into the cryogen stored in the tank; and block means for thermally insulating the removable pump mounting tube from the cryogenic tank at the access port of the cryogenic tank. The mounting tube connecting the tank only at the access port through the block means.

  15. Nanosecond cryogenic Yb:YAG disk laser

    SciTech Connect

    Perevezentsev, E A; Mukhin, I B; Kuznetsov, I I; Vadimova, O L; Palashov, O V

    2014-05-30

    A cryogenic Yb:YAG disk laser is modernised to increase its average and peak power. The master oscillator unit of the laser is considerably modified so that the pulse duration decreases to several nanoseconds with the same pulse energy. A cryogenic disk laser head with a flow-through cooling system is developed. Based on two such laser heads, a new main amplifier is assembled according to an active multipass cell scheme. The total small-signal gain of cryogenic cascades is ∼10{sup 8}. (lasers)

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. Apollo cryogenic integrated systems program

    NASA Technical Reports Server (NTRS)

    Seto, R. K. M.; Cunningham, J. E.

    1971-01-01

    The integrated systems program is capable of simulating both nominal and anomalous operation of the Apollo cryogenics storage system (CSS). Two versions of the program exist; one for the Apollo 14 configuration and the other for J Type Mission configurations. The program consists of two mathematical models which are dynamically coupled. A model of the CSS components and lines determines the oxygen and hydrogen flowrate from each storage tank given the tank pressures and temperatures, and the electrical power subsystem and environmental control subsystem flow demands. Temperatures and pressures throughout the components and lines are also determined. A model of the CSS tankage determines the pressure and temperatures in the tanks given the flowrate from each tank and the thermal environment. The model accounts for tank stretch and includes simplified oxygen tank heater and stratification routines. The program is currently operational on the Univac 1108 computer.

  3. Cryogenic vacuumm RF feedthrough device

    DOEpatents

    Wu, Genfa; Phillips, Harry Lawrence

    2008-12-30

    A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

  4. ESS Cryogenic System Process Design

    NASA Astrophysics Data System (ADS)

    Arnold, P.; Hees, W.; Jurns, J.; Su, X. T.; Wang, X. L.; Weisend, J. G., II

    2015-12-01

    The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 17 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on specific process design criteria, design decisions and their motivations for the helium cryoplants and auxiliary equipment. Key issues for all plants and their process concepts are energy efficiency, reliability, smooth turn-down behaviour and flexibility. The accelerator cryoplant (ACCP) and the target moderator cryoplant (TMCP) in particular need to be prepared for a range of refrigeration capacities due to the intrinsic uncertainties regarding heat load definitions. Furthermore the paper addresses questions regarding process arrangement, 2 K cooling methodology, LN2 precooling, helium storage, helium purification and heat recovery.

  5. 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.

  6. The development of radiant cooler and cryogenic heat pipes for 200K cryogenic optical system cooling

    NASA Astrophysics Data System (ADS)

    Liu, Enguang; Wu, Yinong; Yang, Xiaofeng; Mu, Yongbin

    2016-05-01

    This paper presents a heat transfer system, in which a radiant cooler, cryogenic heat pipes and flexible thermal links were developed for heat transfer, by which a cryogenic system was cooled down to 200K from room temperature. A scrolling mechanism was designed for the radiant cooler to anti-contamination and block sunlight in the initial orbit phase. The cryogenic heat pipe is a type of grooved heat pipe with the working fluid of ethane and working temperature ranging from 160K to 210K. Some experimental and simulation results of the radiant cooler, cryogenic heat pipes will be discussed in this paper.

  7. Advances in cryogenic engineering. Volume 33 - Proceedings of the Cryogenic Engineering Conference, Saint Charles, IL, June 14-18, 1987

    NASA Technical Reports Server (NTRS)

    Fast, R. W. (Editor)

    1988-01-01

    Papers are presented on superconductivity applications including magnets, electronics, rectifiers, magnet stability, coil protection, and cryogenic techniques. Also considered are insulation, heat transfer to liquid helium and nitrogen, heat and mass transfer in He II, superfluid pumps, and refrigeration for superconducting systems. Other topics include cold compressors, refrigeration and liquefaction, magnetic refrigeration, and refrigeration for space applications. Papers are also presented on cryogenic applications, commercial cryogenic plants, the properties of cryogenic fluids, and cryogenic instrumentation and data acquisition.

  8. Resolving stellar surface spots

    NASA Astrophysics Data System (ADS)

    Strassmeier, K. G.; Carroll, T.; Rice, J. B.; Savanov, I. S.

    Doppler imaging of stellar surfaces is a novel technique with similarities to medical brain tomography (instead of a fixed brain and a rotating scanner, astronomers have a fixed spectrograph and a rotating brain, star of course). The number of free (internal) parameters is of the order of the number of surface grid points and only constrained by the number of input data points. This obviously ill-posed situation requires modern inversion algorithms with penalty functions of the form of maximum entropy or Tikhonov etc.. We present a brief status review of our Doppler imaging codes at AIP that span from temperature and spot-filling-factor mapping to full Stokes-based magnetic field mapping.

  9. Rocky Mountain spotted fever.

    PubMed

    Dantas-Torres, Filipe

    2007-11-01

    Rocky Mountain spotted fever (RMSF) is a life-threatening disease caused by Rickettsia rickettsii, an obligately intracellular bacterium that is spread to human beings by ticks. More than a century after its first clinical description, this disease is still among the most virulent human infections identified, being potentially fatal even in previously healthy young people. The diagnosis of RMSF is based on the patient's history and a physical examination, and often presents a dilemma for clinicians because of the non-specific presentation of the disease in its early course. Early empirical treatment is essential to prevent severe complications or a fatal outcome, and treatment should be initiated even in unconfirmed cases. Because there is no vaccine available against RMSF, avoidance of tick-infested areas is still the best way to prevent the infection.

  10. The cryogenic control system of BEPCII

    NASA Astrophysics Data System (ADS)

    Li, Gang; Wang, Ke-Xiang; Zhao, Ji-Jiu; Yue, Ke-Juan; Dai, Ming-Hui; Huang, Yi-Ling; Jiang, Bo

    2008-04-01

    A superconducting cryogenic system has been designed and deployed in the Beijing Electron- Positron Collider Upgrade Project (BEPCII). The system consists of a Siemens PLC (S7-PLC, Programmable Logic Controller) for the compressor control, an Allen Bradley (AB) PLC for the cryogenic equipments, and the Experimental Physics and Industrial Control System (EPICS) that integrates the PLCs. The system fully automates the superconducting cryogenic control with process control, PID (Proportional-Integral-Differential) control loops, real-time data access and data storage, alarm handler and human machine interface. It is capable of automatic recovery as well. This paper describes the BEPCII cryogenic control system, data communication between S7-PLC and EPICS Input/Output Controllers (IOCs), and the integration of the flow control, the low level interlock, the AB-PLC, and EPICS.

  11. 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.

  12. Cryogenic fatigue data developed for Inconel 718

    NASA Technical Reports Server (NTRS)

    Schmidt, E. H.

    1967-01-01

    Data were obtained on the cryogenic fatigue properties of Inconel 718 bar using axial loading and rotating beam fatigue tests. Results also disclosed the fatigue properties of Inconel 718 sheet materials.

  13. Cryogenic target formation using cold gas jets

    DOEpatents

    Hendricks, Charles D.

    1981-01-01

    A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member.

  14. Cryogenic target formation using cold gas jets

    DOEpatents

    Hendricks, C.D.

    1980-02-26

    A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets are disclosed. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member. 4 figs.

  15. Cryogenic target formation using cold gas jets

    DOEpatents

    Hendricks, Charles D. [Livermore, CA

    1980-02-26

    A method and apparatus using cold gas jets for producing a substantially uniform layer of cryogenic materials on the inner surface of hollow spherical members having one or more layers, such as inertially imploded targets. By vaporizing and quickly refreezing cryogenic materials contained within a hollow spherical member, a uniform layer of the materials is formed on an inner surface of the spherical member. Basically the method involves directing cold gas jets onto a spherical member having one or more layers or shells and containing the cryogenic material, such as a deuterium-tritium (DT) mixture, to freeze the contained material, momentarily heating the spherical member so as to vaporize the contained material, and quickly refreezing the thus vaporized material forming a uniform layer of cryogenic material on an inner surface of the spherical member.

  16. Space propulsion technology and cryogenic fluid depot

    NASA Technical Reports Server (NTRS)

    Diehl, Larry A.

    1988-01-01

    Information on space propulsion and technology and the cryogenic fluid depot is given in viewgraph form. Information is given on orbit transfer, electric propulsion, spacecraft propulsion, and program objectives.

  17. Cryogenic Preservation of Granulocytes and Monocytes.

    DTIC Science & Technology

    1982-01-25

    plateletpheresis bags and preserved with the granulocyte protocol. All cells were recovered after 3 months storage in liquid nitrogen with 94...phagocytic index. Technical Reports. Cryogenic preservation of monocytes from human blood and plateletpheresis cellular residues. December 20, 1980. Long...and Callalan, A.B. : Cryogenic preservation of monocytes from human blood and plateletpheresis cellular residues. Blood 57:592-598, 1981. Arnaout, A.A

  18. Filament-wound, fiberglass cryogenic tank supports

    NASA Technical Reports Server (NTRS)

    Carter, J. S.; Timberlake, T. E.

    1971-01-01

    The design, fabrication, and testing of filament-wound, fiberglass cryogenic tank supports for a LH2 tank, a LF2/FLOX tank and a CH4 tank. These supports consist of filament-wound fiberglass tubes with titanium end fittings. These units were satisfactorily tested at cryogenic temperatures, thereby offering a design that can be reliably and economically produced in large or small quantities. The basic design concept is applicable to any situation where strong, lightweight axial load members are desired.

  19. Progress in Cryogenic Target Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    McCrory, R. L.; Meyerhofer, D. D.; Betti, R.; Boehly, T. R.; Craxton, R. S.; Delettrez, J. A.; Edgell, D. H.; Glebov, V. Yu; Goncharov, V. N.; Harding, D. R.; Hu, S. X.; Knauer, J. P.; Marshall, F. J.; McKenty, P. W.; Radha, P. B.; Regan, S. P.; Sangster, T. C.; Seka, W.; Short, R. W.; Shvarts, D.; Skupsky, S.; Smalyuk, V. A.; Soures, J. M.; Stoeckl, C.; Theobald, W.; Yaakobi, B.; Frenje, J. A.; Li, C. K.; Petrasso, R. D.; Séguin, F. H.; Casey, D. T.

    2016-10-01

    Cryogenic deuterium-tritium targets are imploded on the OMEGA Laser System in a direct-drive configuration. Areal densities of approximately 200 mg/cm2 have been measured with implosion velocities of 3 × 107 cm/s. These implosions are used to study the dynamics of cryogenic target compression and to develop areal-density diagnostics that will be used as part of the ignition campaign on the National Ignition Facility.

  20. 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.

  1. Visual-Inspection Probe For Cryogenic Chamber

    NASA Technical Reports Server (NTRS)

    Friend, Steve; Valenzuela, James; Yoshinaga, Jay

    1990-01-01

    Visual-inspection probe that resembles borescope enables observer at ambient temperature to view objects immersed in turbulent flow of liquid oxygen, liquid nitrogen, or other cryogenic fluid. Design of probe fairly conventional, except special consideration given to selection of materials and to thermal expansion to provide for expected range of operating temperatures. Penetrates wall of cryogenic chamber to provide view of interior. Similar probe illuminates scene. View displayed on video monitor.

  2. 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.

  3. Rocky Mountain spotted fever, Colombia.

    PubMed

    Hidalgo, Marylin; Orejuela, Leonora; Fuya, Patricia; Carrillo, Pilar; Hernandez, Jorge; Parra, Edgar; Keng, Colette; Small, Melissa; Olano, Juan P; Bouyer, Donald; Castaneda, Elizabeth; Walker, David; Valbuena, Gustavo

    2007-07-01

    We investigated 2 fatal cases of Rocky Mountain spotted fever that occurred in 2003 and 2004 near the same locality in Colombia where the disease was first reported in the 1930s. A retrospective serosurvey of febrile patients showed that > 21% of the serum samples had antibodies aaainst spotted fever group rickettsiae.

  4. Hot Spot Cosmic Accelerators

    NASA Astrophysics Data System (ADS)

    2002-11-01

    length of more than 3 million light-years, or no less than one-and-a-half times the distance from the Milky Way to the Andromeda galaxy, this structure is indeed gigantic. The region where the jets collide with the intergalactic medium are known as " hot spots ". Superposing the intensity contours of the radio emission from the southern "hot spot" on a near-infrared J-band (wavelength 1.25 µm) VLT ISAAC image ("b") shows three distinct emitting areas; they are even better visible on the I-band (0.9 µm) FORS1 image ("c"). This emission is obviously associated with the shock front visible on the radio image. This is one of the first times it has been possible to obtain an optical/near-IR image of synchrotron emission from such an intergalactic shock and, thanks to the sensitivity and image sharpness of the VLT, the most detailed view of its kind so far . The central area (with the strongest emission) is where the plasma jet from the galaxy centre hits the intergalactic medium. The light from the two other "knots", some 10 - 15,000 light-years away from the central "hot spot", is also interpreted as synchrotron emission. However, in view of the large distance, the astronomers are convinced that it must be caused by electrons accelerated in secondary processes at those sites . The new images thus confirm that electrons are being continuously accelerated in these "knots" - hence called "cosmic accelerators" - far from the galaxy and the main jets, and in nearly empty space. The exact physical circumstances of this effect are not well known and will be the subject of further investigations. The present VLT-images of the "hot spots" near 3C 445 may not have the same public appeal as some of those beautiful images that have been produced by the same instruments during the past years. But they are not less valuable - their unusual importance is of a different kind, as they now herald the advent of fundamentally new insights into the mysteries of this class of remote and active

  5. Cryogenic ion chemistry and spectroscopy.

    PubMed

    Wolk, Arron B; Leavitt, Christopher M; Garand, Etienne; Johnson, Mark A

    2014-01-21

    The use of mass spectrometry in macromolecular analysis is an incredibly important technique and has allowed efficient identification of secondary and tertiary protein structures. Over 20 years ago, Chemistry Nobelist John Fenn and co-workers revolutionized mass spectrometry by developing ways to non-destructively extract large molecules directly from solution into the gas phase. This advance, in turn, enabled rapid sequencing of biopolymers through tandem mass spectrometry at the heart of the burgeoning field of proteomics. In this Account, we discuss how cryogenic cooling, mass selection, and reactive processing together provide a powerful way to characterize ion structures as well as rationally synthesize labile reaction intermediates. This is accomplished by first cooling the ions close to 10 K and condensing onto them weakly bound, chemically inert small molecules or rare gas atoms. This assembly can then be used as a medium in which to quench reactive encounters by rapid evaporation of the adducts, as well as provide a universal means for acquiring highly resolved vibrational action spectra of the embedded species by photoinduced mass loss. Moreover, the spectroscopic measurements can be obtained with readily available, broadly tunable pulsed infrared lasers because absorption of a single photon is sufficient to induce evaporation. We discuss the implementation of these methods with a new type of hybrid photofragmentation mass spectrometer involving two stages of mass selection with two laser excitation regions interfaced to the cryogenic ion source. We illustrate several capabilities of the cryogenic ion spectrometer by presenting recent applications to peptides, a biomimetic catalyst, a large antibiotic molecule (vancomycin), and reaction intermediates pertinent to the chemistry of the ionosphere. First, we demonstrate how site-specific isotopic substitution can be used to identify bands due to local functional groups in a protonated tripeptide designed to

  6. Layered composite thermal insulation system for nonvacuum cryogenic applications

    NASA Astrophysics Data System (ADS)

    Fesmire, J. E.

    2016-03-01

    A problem common to both space launch applications and cryogenic propulsion test facilities is providing suitable thermal insulation for complex cryogenic piping, tanks, and components that cannot be vacuum-jacketed or otherwise be broad-area-covered. To meet such requirements and provide a practical solution to the problem, a layered composite insulation system has been developed for nonvacuum applications and extreme environmental exposure conditions. Layered composite insulation system for extreme conditions (or LCX) is particularly suited for complex piping or tank systems that are difficult or practically impossible to insulate by conventional means. Consisting of several functional layers, the aerogel blanket-based system can be tailored to specific thermal and mechanical performance requirements. The operational principle of the system is layer-pairs working in combination. Each layer pair is comprised of a primary insulation layer and a compressible radiant barrier layer. Vacuum-jacketed piping systems, whether part of the ground equipment or the flight vehicle, typically include numerous terminations, disconnects, umbilical connections, or branches that must be insulated by nonvacuum means. Broad-area insulation systems, such as spray foam or rigid foam panels, are often the lightweight materials of choice for vehicle tanks, but the plumbing elements, feedthroughs, appurtenances, and structural supports all create ;hot spot; areas that are not readily insulated by similar means. Finally, the design layouts of valve control skids used for launch pads and test stands can be nearly impossible to insulate because of their complexity and high density of components and instrumentation. Primary requirements for such nonvacuum thermal insulation systems include the combination of harsh conditions, including full weather exposure, vibration, and structural loads. Further requirements include reliability and the right level of system breathability for thermal

  7. Saturn's Hot Spot

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This is the sharpest image of Saturn's temperature emissions taken from the ground; it is a mosaic of 35 individual exposures made at the W.M. Keck I Observatory, Mauna Kea, Hawaii on Feb. 4, 2004.

    The images to create this mosaic were taken with infrared radiation. The mosaic was taken at a wavelength near 17.65 microns and is sensitive to temperatures in Saturn's upper troposphere. The prominent hot spot at the bottom of the image is right at Saturn's south pole. The warming of the southern hemisphere was expected, as Saturn was just past southern summer solstice, but the abrupt changes in temperature with latitude were not expected. The tropospheric temperature increases toward the pole abruptly near 70 degrees latitude from 88 to 89 Kelvin (-301 to -299 degrees Fahrenheit) and then to 91 Kelvin (-296 degrees Fahrenheit) right at the pole.

    Ring particles are not at a uniform temperature everywhere in their orbit around Saturn. The ring particles are orbiting clockwise in this image. Particles are coldest just after having cooled down in Saturn's shadow (lower left). As they orbit Saturn, the particles increase in temperature up to a maximum (lower right) just before passing behind Saturn again in shadow.

    A small section of the ring image is missing because of incomplete mosaic coverage during the observing sequence.

  8. The future of cryogenic propulsion

    NASA Astrophysics Data System (ADS)

    Palerm, S.; Bonhomme, C.; Guelou, Y.; Chopinet, J. N.; Danous, P.

    2015-07-01

    As the French Space Agency, CNES is funding an ambitious program to identify, develop and evaluate the technologies and skills that will enable to design cost efficient future launchers. This program deals together with, researches for mastering complex physical phenomena, set ups of robust and efficient numerical tools for design and justification, and identification of innovative manufacturing processes and hardware. It starts from low Technical Readiness Level (TRL 2) up to a maturation of TRL 6 with the use of demonstrators, level that allows to be ready for a development. This paper focuses on cryogenic propulsion activities conducted with SNECMA and French laboratories to prepare next generation engines. The physics in that type of hardware addresses a large range of highly complex phenomena, among them subcritical and supercritical combustion and possible associated High Frequency oscillations in combustion devices, tribology in bearings and seals, cavitation and rotordynamics in turbopump. The research activities conducted to master those physical phenomena are presented. Moreover, the operating conditions of these engines are very challenging, both thermally and mechanically. The innovative manufacturing processes and designs developed to cope with these conditions while filling cost reduction requirements are described. Finally, the associated demonstrators put in place to prepare the implementation of these new technologies on future engines are presented.

  9. 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.

  10. Single spots, unipolar magnetic regions, and pairs of spots

    NASA Astrophysics Data System (ADS)

    Akasofu, S.-I.

    2014-06-01

    McIntosh (1981) noted that sunspot pairs appear preferentially near the boundary of unipolar magnetic (UM) regions of opposite polarity. A large number of solar magnetograms from the Mount Wilson Observatory and the Kitt Peak Observatory during fairly quiet periods are examined to confirm his finding. In this study, it is also found collaterally that positive single spots appear in a positive UM region and vice versa. It is suggested thus that a pair of spots of opposite polarity is formed because two single spots develop in the vicinity of the boundary (the neutral line) of two UM regions of opposite polarity for polarity arrangement appropriate to the Hale law, namely, the Hale boundary. For these reasons, it is suggested that single spots and UM regions have significant meaning in solar magnetism.

  11. 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.

  12. The Future with Cryogenic Fluid Dynamics

    NASA Astrophysics Data System (ADS)

    Scurlock, R. G.

    The applications of cryogenic systems have expanded over the past 50 years into many areas of our lives. During this time, the impact of the common features of Cryogenic Fluid Dynamics, CryoFD, on the economic design of these cryogenic systems, has grown out of a long series of experimental studies carried out by teams of postgraduate students at Southampton University.These studies have sought to understand the heat transfer and convective behavior of cryogenic liquids and vapors, but they have only skimmed over the many findings made, on the strong convective motions of fluids at low temperatures. The convection takes place in temperature gradients up to 10,000 K per meter, and density gradients of 1000% per meter and more, with rapid temperature and spatially dependent changes in physical properties like viscosity and surface tension, making software development and empirical correlations almost impossible to achieve. These temperature and density gradients are far larger than those met in other convecting systems at ambient temperatures, and there is little similarity. The paper will discuss the likely impact of CryoFD on future cryogenic systems, and hopefully inspire further research to support and expand the use of existing findings, and to improve the economy of present-day systems even more effectively. Particular examples to be mentioned include the following. Doubling the cooling power of cryo-coolers by a simple use of CryoFD. Reducing the boil-off rate of liquid helium stored at the South Pole, such that liquid helium availability is now all-the-year-round. Helping to develop the 15 kA current leads for the LHC superconducting magnets at CERN, with much reduced refrigeration loads. Improving the heat transfer capability of boiling heat transfer surfaces by 10 to 100 fold. This paper is an edited text of an invited plenary presentation at ICEC25/ICMC2014 by Professor Scurlock on the occasion of his being presented with the ICEC Mendelssohn Award for his

  13. Cryogenic Applications of Commercial Electronic Components

    NASA Technical Reports Server (NTRS)

    Buchanan, Ernest D.; Benford, Dominic J.; Forgione, Joshua B.; Moseley, S. Harvey; Wollack, Edward J.

    2012-01-01

    We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2K), using commercially available low power components. The challenges encountered in designing cryogenic electronics include finding components that can function usefully in the cold and possess low enough power dissipation so as not to heat the systems they are designed to measure. From design, test, and integration perspectives it is useful for components to operate similarly at room and cryogenic temperatures; however this is not a necessity. Some of the circuits presented here have been used successfully in the MUSTANG and in the GISMO camera to build a complete digital to analog multiplexer (which will be referred to as the Cryogenic Address Driver board). Many of the circuit elements described are of a more general nature rather than specific to the Cryogenic Address Driver board, and were studied as a part of a more comprehensive approach to addressing a larger set of cryogenic electronic needs.

  14. Advanced cryogenics for cutting tools. Final report

    SciTech Connect

    Lazarus, L.J.

    1996-10-01

    The purpose of the investigation was to determine if cryogenic treatment improved the life and cost effectiveness of perishable cutting tools over other treatments or coatings. Test results showed that in five of seven of the perishable cutting tools tested there was no improvement in tool life. The other two tools showed a small gain in tool life, but not as much as when switching manufacturers of the cutting tool. The following conclusions were drawn from this study: (1) titanium nitride coatings are more effective than cryogenic treatment in increasing the life of perishable cutting tools made from all cutting tool materials, (2) cryogenic treatment may increase tool life if the cutting tool is improperly heat treated during its origination, and (3) cryogenic treatment was only effective on those tools made from less sophisticated high speed tool steels. As a part of a recent detailed investigation, four cutting tool manufacturers and two cutting tool laboratories were queried and none could supply any data to substantiate cryogenic treatment of perishable cutting tools.

  15. 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.

  16. 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.

  17. Cryogenic applications of commercial electronic components

    NASA Astrophysics Data System (ADS)

    Buchanan, Ernest D.; Benford, Dominic J.; Forgione, Joshua B.; Harvey Moseley, S.; Wollack, Edward J.

    2012-10-01

    We have developed a range of techniques useful for constructing analog and digital circuits for operation in a liquid Helium environment (4.2 K), using commercially available low power components. The challenges encountered in designing cryogenic electronics include finding components that can function usefully in the cold and possess low enough power dissipation so as not to heat the systems they are designed to measure. From design, test, and integration perspectives it is useful for components to operate similarly at room and cryogenic temperatures; however this is not a necessity. Some of the circuits presented here have been used successfully in the MUSTANG [1] and in the GISMO [2] camera to build a complete digital to analog multiplexer (which will be referred to as the Cryogenic Address Driver board). Many of the circuit elements described are of a more general nature rather than specific to the Cryogenic Address Driver board, and were studied as a part of a more comprehensive approach to addressing a larger set of cryogenic electronic needs.

  18. 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.

  19. Aerogel Blanket Insulation Materials for Cryogenic Applications

    NASA Technical Reports Server (NTRS)

    Coffman, B. E.; Fesmire, J. E.; White, S.; Gould, G.; Augustynowicz, S.

    2009-01-01

    Aerogel blanket materials for use in thermal insulation systems are now commercially available and implemented by industry. Prototype aerogel blanket materials were presented at the Cryogenic Engineering Conference in 1997 and by 2004 had progressed to full commercial production by Aspen Aerogels. Today, this new technology material is providing superior energy efficiencies and enabling new design approaches for more cost effective cryogenic systems. Aerogel processing technology and methods are continuing to improve, offering a tailor-able array of product formulations for many different thermal and environmental requirements. Many different varieties and combinations of aerogel blankets have been characterized using insulation test cryostats at the Cryogenics Test Laboratory of NASA Kennedy Space Center. Detailed thermal conductivity data for a select group of materials are presented for engineering use. Heat transfer evaluations for the entire vacuum pressure range, including ambient conditions, are given. Examples of current cryogenic applications of aerogel blanket insulation are also given. KEYWORDS: Cryogenic tanks, thermal insulation, composite materials, aerogel, thermal conductivity, liquid nitrogen boil-off

  20. Cryogenic System for the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    Arenius, D.; Chronis, W.; Creel, J.; Dixon, K.; Ganni, V.; Knudsen, P.

    2004-06-01

    The Spallation Neutron Source (SNS) is a neutron-scattering facility being built at Oak Ridge, TN for the US Department of Energy. The SNS accelerator linac consists of superconducting radio-frequency (SRF) cavities in cryostats (cryomodules). The linac cryomodules are cooled to 2.1 K by a 2300 watt cryogenic refrigeration system. As an SNS partner laboratory, Jefferson Lab is responsible for the installed integrated cryogenic system design for the SNS linac accelerator consisting of major subsystem equipment engineered and procured from industry. Jefferson Lab's work included developing the major vendor subsystem equipment procurement specifications, equipment procurement, and the integrated system engineering support of the field installation and commissioning. The major cryogenic system components include liquid nitrogen storage, gaseous helium storage, cryogen distribution transfer line system, 2.1-K cold box consisting of four stages of cold compressors, 4.5-K cold box, warm helium compressors with its associated oil removal, gas management, helium purification, gas impurity monitoring systems, and the supportive utilities of electrical power, cooling water and instrument air. The system overview, project organization, the important aspects, and the capabilities of the cryogenic system are described.

  1. Weird Warm Spot on Exoplanet

    NASA Video Gallery

    This animation illustrates an unexpected warm spot on the surface of a gaseous exoplanet. NASA's Spitzer Space Telescope discovered that the hottest part of the planet, shown here as bright, orange...

  2. Center Spot: Shoe Box Science

    ERIC Educational Resources Information Center

    Hoffman, Jan

    1976-01-01

    This is the second "Center Spot" devoted to Jan Hoffman's "Shoe Box Science," a program that organizes manipulative materials so that children can identify, describe, order, construct, name and distinguish on their own.

  3. Energy Efficient Cryogenics on Earth and in Space

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.

    2012-01-01

    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 energy-efficient cryogenics on Earth and in space.

  4. Cryogenic Amplifier Based Receivers at Submillimeter Wavelengths

    NASA Technical Reports Server (NTRS)

    Chattopadhyay, Goutam; Reck, Theodore and; Schlecht, Erich; Lin, Robert; Deal, William

    2012-01-01

    The operating frequency of InP high electron mobility transistor (HEMT) based amplifiers has moved well in the submillimeter-wave frequencies over the last couple of years. Working amplifiers with usable gain in waveguide packages has been reported beyond 700 GHz. When cooled cryogenically, they have shown substantial improvement in their noise temperature. This has opened up the real possibility of cryogenic amplifier based heterodyne receivers at submillimeter wavelengths for ground-based, air-borne, and space-based instruments for astrophysics, planetary, and Earth science applications. This paper provides an overview of the science applications at submillimeter wavelengths that will benefit from this technology. It also describes the current state of the InP HEMT based cryogenic amplifier receivers at submillimeter wavelengths.

  5. 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.

  6. Designs of pulsed power cryogenic transformers

    SciTech Connect

    Singh, S.K.; Heyne, C.J.; Hackowrth, D.T.; Shestak, E.J.; Eckels, P.W.; Rogers, J.D.

    1988-03-01

    The Westinghouse Electric Corporation has completed designs of three pulsed power cryogenic transformers of three pulsed power cryogenic transformers for the Los Alamos National Laboratory. These transformers will be configured to transfer their stored energy sequentially to an electro-magnetic launcher and form a three-stage power supply. The pulse transformers will act as two winding energy storage solenoids which provide a high current and energy pulse compression by transforming a 50 kA power supply into a megamp level power supply more appropriate for the electromagnetic launcher duty. This system differs from more traditional transformer applications in that significant current levels do not exists simultaneously in the two windings of the pulse transformer. This paper describes the designs of the pulsed power cryogenic transformers.

  7. Long term storage of cryogens in space

    NASA Technical Reports Server (NTRS)

    Fester, D. A.; Eberhardt, R. N.

    1982-01-01

    Experimental design procedures leading to the configuration of a space-based cryogenic fluids test system are reported. Large quantities of cryogenic fluids are expected to be required in space for cooling systems, chemical and electrical OTVs, and resupply tankers. The design was guided by the necessity for representative storage and supply systems to be compatible with the Shuttle. Consideration was given to liquid hydrogen, oxygen, methane, and argon containers and concommitant fluid dynamics, thermal, and structural analyses. A 5% initial ullage was included for the liquids, except for methane, which was calculated at 8.9%. The Ar, CH4, and O2 tanks were set at 12.5 cu m, while the H2 tank was 37.4 cu m. The orbital experiment is required to provide actual thermal stabilization lags in a zero-g environment. Details of the Cryogenic Fluid Management Facility test module for flight on board the Shuttle are presented.

  8. Cryogenic Fluid Management Flight Experiment (CFMFE)

    NASA Technical Reports Server (NTRS)

    Defelice, David M.

    1987-01-01

    Since its foundation, NASA has excelled in the study and development of microgravity fluid management technology. With the advent of space-based vehicles and systems, the use of and the ability to efficiently manage subcritical cryogens in the space environment has become necessary to our growing space program. The NASA Lewis Research Center is responsible for the planning and execution of a program which will provide advanced in-space cryogenic fluid management technology. A number of future space missions have been identified that will require or could benefit from this technology. These technology needs have been prioritized and the Cryogenic Fluid Management Flight Experiment (CFMFE) is being designed to provide the experimental data necessary for the technological development effort.

  9. Conceptual design of the FRIB cryogenic system

    SciTech Connect

    Weisend II, J G; Bull, Brad; Burns, Chris; Fila, Adam; Kelley, Patrick; Laumer, Helmut; Mann, Thomas; McCartney, Allyn; Jones, S; Zeller, A

    2012-06-01

    The Facility for Rare Isotope Beams (FRIB) is a new nuclear science facility funded by the DOE Office of Science and Michigan State University (MSU). FRIB is currently under design and will be located on the MSU campus. The centerpiece of FRIB is a heavy ion linac utilizing superconducting RF cavities and magnets which in turn requires a large cryogenic system. The cryogenic system consists of a commercially produced helium refrigeration plant and an extensive distribution system. Superconducting components will operate at both 4.5 K and 2 K. This paper describes the conceptual design of the system including the expected heat loads and operating modes. The strategy for procuring a custom turnkey helium refrigeration plant from industry, an overview of the distribution system, the interface of the cryogenic system to the conventional facilities and the project schedule are also described.

  10. 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.

  11. Advanced long term cryogenic storage systems

    NASA Technical Reports Server (NTRS)

    Brown, Norman S.

    1987-01-01

    Long term, cryogenic fluid storage facilities will be required to support future space programs such as the space-based Orbital Transfer Vehicle (OTV), Telescopes, and Laser Systems. An orbital liquid oxygen/liquid hydrogen storage system with an initial capacity of approximately 200,000 lb will be required. The storage facility tank design must have the capability of fluid acquisition in microgravity and limit cryogen boiloff due to environmental heating. Cryogenic boiloff management features, minimizing Earth-to-orbit transportation costs, will include advanced thick multilayer insulation/integrated vapor cooled shield concepts, low conductance support structures, and refrigeration/reliquefaction systems. Contracted study efforts are under way to develop storage system designs, technology plans, test article hardware designs, and develop plans for ground/flight testing.

  12. Spacelab 2 infrared telescope cryogenic system

    NASA Technical Reports Server (NTRS)

    Urban, E. W.; Katz, L.; Hendricks, J. B.; Karr, G. R.

    1979-01-01

    The paper discusses the development of a cryogenic helium system to provide cooling to a scanning infrared telescope for the Spacelab 2 mission. The infrared optical/detector system and related electronics are being developed by the Smithsonian Astrophysical Observatory and the University of Arizona. A superfluid helium dewar and porous plug phase separator permit gas cooling of the infrared focal plane assembly to about 2.5 K, and of the two telescope sections to 8 K and 60 K. The design of the cryogenic system,including a commandable vacuum cover, and the prelaunch liquid helium servicing and maintenance approach were discussed. It is concluded that the system will satisfy the Infrared Telescope requirements, and the superfluid helium system shall be capable of satisfying cryogenic helium cooled requirements for the next several years.

  13. Cryogenic surface-electrode ion trap apparatus

    NASA Astrophysics Data System (ADS)

    Dubielzig, Timko; Carsjens, Martina; Kohnen, Matthias; Grondkowski, Sebastian; Ospelkaus, Christian

    2014-05-01

    In this talk we describe the infrastructure necessary to operate a surface-electrode ion trap with integrated microwave conductors for near-field quantum control of 9Be+ in a cryogenic environment. These traps are promising systems for analog quantum simulators and for quantum logic applications. Our group recently developed a trap with an integrated meander-like microwave guide for driving motional sidebands on an 9Be+ ion. The trap will be operated in a cryogenic vacuum chamber. We will discuss the vibrational isolated closed cycle cryostat and the design of the vacuum chamber with all electrical supplies necessary to apply two different microwave currents, dc voltages and three independent rf supplies to generate a reconfigurable rf trapping potential. We will also discuss the used hyperfine qubit and the laser systems required to cool and repump. Furthermore we will present the cryogenic, high aperture and fully acromatic imaging system.

  14. Cryogenic Propellant Storage and Transfer (CPST) Technology Demonstration Mission (TDM)

    NASA Technical Reports Server (NTRS)

    Chojnacki, Kent

    2013-01-01

    Objectives: 1) Store cryogenic propellants in a manner that maximizes their availability for use regardless of mission duration. 2) Efficiently transfer conditioned cryogenic propellant to an engine or tank situated in a microgravity environment. 3) Accurately monitor and gauge cryogenic propellants situated in a microgravity environment.

  15. 49 CFR 173.320 - Cryogenic liquids; exceptions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 2 2011-10-01 2011-10-01 false Cryogenic liquids; exceptions. 173.320 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.320 Cryogenic liquids; exceptions. (a) Atmospheric gases and helium, cryogenic liquids, in Dewar flasks, insulated...

  16. 49 CFR 173.320 - Cryogenic liquids; exceptions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Cryogenic liquids; exceptions. 173.320 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.320 Cryogenic liquids; exceptions. (a) Atmospheric gases and helium, cryogenic liquids, in Dewar flasks, insulated...

  17. 49 CFR 173.320 - Cryogenic liquids; exceptions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 2 2012-10-01 2012-10-01 false Cryogenic liquids; exceptions. 173.320 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.320 Cryogenic liquids; exceptions. (a) Atmospheric gases and helium, cryogenic liquids, in Dewar flasks, insulated...

  18. 49 CFR 173.320 - Cryogenic liquids; exceptions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 2 2013-10-01 2013-10-01 false Cryogenic liquids; exceptions. 173.320 Section 173... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.320 Cryogenic liquids; exceptions. (a) Atmospheric gases and helium, cryogenic liquids, in Dewar flasks, insulated...

  19. 21 CFR 882.4250 - Cryogenic surgical device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cryogenic surgical device. 882.4250 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A cryogenic surgical device is a device used to destroy nervous tissue or...

  20. 21 CFR 882.4250 - Cryogenic surgical device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cryogenic surgical device. 882.4250 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A cryogenic surgical device is a device used to destroy nervous tissue or...

  1. 21 CFR 882.4250 - Cryogenic surgical device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cryogenic surgical device. 882.4250 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A cryogenic surgical device is a device used to destroy nervous tissue or...

  2. 21 CFR 882.4250 - Cryogenic surgical device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cryogenic surgical device. 882.4250 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A cryogenic surgical device is a device used to destroy nervous tissue or...

  3. 21 CFR 882.4250 - Cryogenic surgical device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cryogenic surgical device. 882.4250 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device. (a) Identification. A cryogenic surgical device is a device used to destroy nervous tissue or...

  4. Resolving Ultrafast Heating of Dense Cryogenic Hydrogen

    NASA Astrophysics Data System (ADS)

    Zastrau, U.; Sperling, P.; Harmand, M.; Becker, A.; Bornath, T.; Bredow, R.; Dziarzhytski, S.; Fennel, T.; Fletcher, L. B.; Förster, E.; Göde, S.; Gregori, G.; Hilbert, V.; Hochhaus, D.; Holst, B.; Laarmann, T.; Lee, H. J.; Ma, T.; Mithen, J. P.; Mitzner, R.; Murphy, C. D.; Nakatsutsumi, M.; Neumayer, P.; Przystawik, A.; Roling, S.; Schulz, M.; Siemer, B.; Skruszewicz, S.; Tiggesbäumker, J.; Toleikis, S.; Tschentscher, T.; White, T.; Wöstmann, M.; Zacharias, H.; Döppner, T.; Glenzer, S. H.; Redmer, R.

    2014-03-01

    We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of ˜0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory.

  5. 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

  6. 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.

  7. Cryogenic fluid management experiment trunnion fatigue verification

    NASA Technical Reports Server (NTRS)

    Bailey, W. J.; Fester, D. A.; Toth, J. M., Jr.; Kasper, H. J.

    1983-01-01

    A subcritical liquid hydrogen orbital storage and transfer experiment was designed for flight in the Shuttle cargo bay. The Cryogenic Fluid Management Experiment (CFME) includes a liquid hydrogen tank supported in a vacuum jacket by two fiberglass epoxy trunnion mounts. This composite material was selected for the trunnions since it provides desirable strength, weight and thermal characteristics for supporting cryogenic tankage. An experimental program was conducted to provide material property and fatigue data for S-glass epoxy composite materials at ambient and liquid hydrogen temperatures and to verify structural integrity of the CFME trunnion supports.

  8. Sorption cryogenic refrigeration - Status and future

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.

    1988-01-01

    The operation principles of sorption cryogenic refrigeration are discussed. Sorption refrigerators have virtually no wear-related moving parts, have negligible vibration, and offer extremely long life (at least ten years), making it possible to obtain efficient, long life and low vibration cooling to as low as 7 K for cryogenic sensors. The physisorption and chemisorption systems recommended for various cooling ranges down to 7 K are described in detail. For long-life cooling at 4-5 K temperatures, a hybrid chemisorption-mechanical refrigeration system is recommended.

  9. Adjustable expandable cryogenic piston and ring

    DOEpatents

    Mazur, Peter O.; Pallaver, Carl B.

    1980-01-01

    The operation of a reciprocating expansion engine for cryogenic refrigeration is improved by changing the pistons and rings so that the piston can be operated from outside the engine to vary the groove in which the piston ring is located. This causes the ring, which is of a flexible material, to be squeezed so that its contact with the wall is subject to external control. This control may be made manually or it may be made automatically in response to instruments that sense the amount of blow-by of the cryogenic fluid and adjust for an optimum blow-by.

  10. The new cryogenic facility at LMA

    NASA Astrophysics Data System (ADS)

    Degallaix, Jérôme; Flaminio, Raffaele; Forest, Danièle; Franc, Janyce; Gautier, Kevin; Granata, Massimo; Lagrange, Bernard; Michel, Christophe; Morgado, Nazario; Pinard, Laurent; Saracco, Emeline; Benoit, Quentin

    2012-06-01

    To support the research effort for the third generation of gravitational wave interferometers, the Laboratoire des Matériaux Avancés (LMA) at Lyon, France has developed a new cryogenic facility to characterize optics at low temperature. The new cryostat is installed in a clean room and allows samples to be cooled down to 10 Kelvin in around 12 hours. Currently, two independent experiments have been installed in the cryostat: the measure of the optical absorption of silicon and the measurement of the coating mechanical loss. After a short presentation of the cryogenic and optical setup, preliminary results from the optical absorption experiment will be presented.

  11. CRYOGENIC AND VACUUM TECHNOLOGICAL ASPECTS OF THE LOW-ENERGY ELECTROSTATIC CRYOGENIC STORAGE RING

    SciTech Connect

    Orlov, D. A.; Lange, M.; Froese, M.; Hahn, R. von; Grieser, M.; Mallinger, V.; Sieber, T.; Weber, T.; Wolf, A.; Rappaport, M.

    2008-03-16

    The cryogenic and vacuum concepts for the electrostatic Cryogenic ion Storage Ring (CSR), under construction at the Max-Planck-Institut fuer Kernphysik in Heidelberg, is presented. The ring will operate in a broad temperature range from 2 to 300 K and is required to be bakeable up to 600 K. Extremely high vacuum and low temperatures are necessary to achieve long lifetimes of the molecular ions stored in the ring so that the ions will have enough time to cool by radiation to their vibrational and rotational ground states. To test cryogenic and vacuum technological aspects of the CSR, a prototype is being built and will be connected to the commercial cryogenic refrigerator recently installed, including a specialized 2-K connection system. The first results and the status of current work with the prototype are also presented.

  12. Research on On-Orbit Storage Scheme of Cryogenic Propellant

    NASA Astrophysics Data System (ADS)

    Xiaolin, Dong

    2016-07-01

    For manned deep space explorations as lunar and mars exploration,the cryogenic propellant is required to be on-orbit for a long time, from several days to years. However, because of the low boiling point of cryogenic propellant, it is easy to be boiled off. We should pay attention to the heat transfer path and influencing factors of cryogenic propellant on-orbit storage. This Paper proposed a scheme of cryogenic propellant on-orbit storage and gave an analysis of the key technologies, in order to promote the on-orbit application of cryogenic propellant.

  13. Method of measuring heat influx of a cryogenic transfer system

    DOEpatents

    Niemann, Ralph C.; Zelipsky, Steven A.; Rezmer, Ronald R.; Smelser, Peter

    1981-01-01

    A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

  14. Cryogenic Technology, part 1. [conference proceedings; cryogenic wind tunnel design and instrumentation

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Different engineering problems associated with the design of mechanisms and systems to operate in a cryogenic environment are discussed. The focal point for the entire engineering effort was the design of the National Transonic Facility, which is a closed-circuit cryogenic wind tunnel. The papers covered a variety of mechanical, structural, and systems design subjects including thermal structures insulation systems, noise, seals, and materials.

  15. Effect of entry of subcooled cryogen on thermal stratification in a cryogenic storage tank

    NASA Technical Reports Server (NTRS)

    Wang, Pao-lien

    1995-01-01

    The purpose of this study was to predict if subcooled cryogenic liquid entering the bottom of a storage tank will destroy the thermal stratification of the tank. After an extensive literature search, a formula for maximum critical Reynolds Number which used to predict the destratification of a cryogenic tank was found. Example of calculations and graphics to determine the mixing of fluid in the tank were presented.

  16. 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.

  17. Cryogenic propellant prestart conditioning for NLS

    NASA Technical Reports Server (NTRS)

    Gaynor, T. L.; Merlin, M. V.; Gautney, T. T.

    1992-01-01

    An overview is presented of a candidate National Launch System (NLS) passive cryogenic propellant prestart conditioning system that offers a stable propellant thermal environment and minimum system complexity. A 2D, multinode model utilizing real fluid properties was developed. This model predicts flow recirculation due to thermal gradients by assuming vertical cold and warm opposing flow streams produced by density differential.

  18. Cryogenic Heat Exchanger with Turbulent Flows

    ERIC Educational Resources Information Center

    Amrit, Jay; Douay, Christelle; Dubois, Francis; Defresne, Gerard

    2012-01-01

    An evaporator-type cryogenic heat exchanger is designed and built for introducing fluid-solid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N[subscript 2] and He gases from room temperatures. We present first the experimental results of…

  19. Jacketed cryogenic piping is stress relieved

    NASA Technical Reports Server (NTRS)

    Bowers, W. M.

    1967-01-01

    Jacketed design of piping used to transfer cryogenic fluids, relieves severe stresses associated with the temperature gradients that occur during transfer cycles and ambient periods. The inner /transfer/ pipe is preloaded in such a way that stress relief takes place automatically as cycling occurs.

  20. 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.

  1. 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.

  2. Cryogenic Propellant Boil-Off Reduction System

    NASA Astrophysics Data System (ADS)

    Plachta, D. W.; Christie, R. J.; Carlberg, E.; Feller, J. R.

    2008-03-01

    Lunar missions under consideration would benefit from incorporation of high specific impulse propellants such as LH2 and LO2, even with their accompanying boil-off losses necessary to maintain a steady tank pressure. This paper addresses a cryogenic propellant boil-off reduction system to minimize or eliminate boil-off. Concepts to do so were considered under the In-Space Cryogenic Propellant Depot Project. Specific to that was an investigation of cryocooler integration concepts for relatively large depot sized propellant tanks. One concept proved promising—it served to efficiently move heat to the cryocooler even over long distances via a compressed helium loop. The analyses and designs for this were incorporated into NASA Glenn Research Center's Cryogenic Analysis Tool. That design approach is explained and shown herein. Analysis shows that, when compared to passive only cryogenic storage, the boil-off reduction system begins to reduce system mass if durations are as low as 40 days for LH2, and 14 days for LO2. In addition, a method of cooling LH2 tanks is presented that precludes development issues associated with LH2 temperature cryocoolers.

  3. NASA cryogenic fluid management space experiment efforts

    NASA Technical Reports Server (NTRS)

    Glover, Daniel

    1991-01-01

    A history of technological development for subcritical cryogenic fluid management (CFM) through space experiments is given for the period 1960 to 1990. Space experiments with liquid hydrogen were conducted in the early 1960s. Efforts since then have consisted of studies and designs of potential space experiments. A chronology of CFM space experiments and design efforts is included.

  4. 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).

  5. 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.

  6. Preliminary Thermal Design of Cryogenic Radiation Shielding

    NASA Technical Reports Server (NTRS)

    Li, Xiaoyi; Mustafi, Shuvo; Boutte, Alvin

    2015-01-01

    Cryogenic Hydrogen Radiation Shielding (CHRS) is the most mass efficient material radiation shielding strategy for human spaceflight beyond low Earth orbit (LEO). Future human space flight, mission beyond LEO could exceed one year in duration. Previous radiation studies showed that in order to protect the astronauts from space radiation with an annual allowable radiation dose less than 500 mSv, 140 kgm2 of polyethylene is necessary. For a typical crew module that is 4 meter in diameter and 8 meter in length. The mass of polyethylene radiation shielding required would be more than 17,500 kg. The same radiation study found that the required hydrogen shielding for the same allowable radiation dose is 40 kgm2, and the mass of hydrogen required would be 5, 000 kg. Cryogenic hydrogen has higher densities and can be stored in relatively small containment vessels. However, the CHRS system needs a sophisticated thermal system which prevents the cryogenic hydrogen from evaporating during the mission. This study designed a cryogenic thermal system that protects the CHRS from hydrogen evaporation for one to up to three year mission. The design also includes a ground based cooling system that can subcool and freeze liquid hydrogen. The final results show that the CHRS with its required thermal protection system is nearly half of the mass of polyethylene radiation shielding.

  7. Energy Efficient Storage and Transfer of Cryogens

    NASA Technical Reports Server (NTRS)

    Fesmire, James E.

    2013-01-01

    Cryogenics is globally linked to energy generation, storage, and usage. Thermal insulation systems research and development is an enabling part of NASA's technology goals for Space Launch and Exploration. New thermal testing methodologies and materials are being transferred to industry for a wide range of commercial applications.

  8. The Stirling cycle and cryogenic refrigerators

    SciTech Connect

    Louie, B.; Radebaugh, R.

    1984-08-01

    This paper reviews the principles and techniques used in cryogenic refrigeration, with particular emphasis on small cryocoolers. Several thermodynamic cycles used in cryocoolers are discussed, as are the design requirements, applications, and current areas of research. The important features of the Stirling cycle used as a prime mover or refrigerator are compared.

  9. Elastic vacuum seal for cryogenic temperatures

    SciTech Connect

    Kolenko, E.A.

    1988-06-01

    Cold-hardened silicone rubber is proposed as a vacuum seal in units that contain materials with vastly different expansion coefficients and which operate at cryogenic temperatures. The cold vulcanization process and the polymerization catalyst used to accelerate and stabilize the process are described. Test results obtained for vacuum tightness in liquid nitrogen are assessed.

  10. 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.

  11. Fiber optic level sensor for cryogens

    NASA Technical Reports Server (NTRS)

    Sharma, M.

    1981-01-01

    Sensor is useful in cryogenic environments where liquids of very low index of refraction are encountered. It is "yes/no" indication of whether liquid is in contact with sensor. Sharp bends in fiber alter distribution of light among propagation modes. This amplifies change in light output observed when sensor contacts liquid, without requiring long fiber that would increse insertion loss.

  12. 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.

  13. 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.

  14. 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.

  15. Intermittency Models and Spot Measurements

    NASA Technical Reports Server (NTRS)

    Ashworth, D. A.

    2007-01-01

    Experimental work at the University of Oxford Osney Lab has demonstrated characteristics of the late-stage transition process by the use of thin-film heat transfer gauges. The development of turbulent spots has been observed in a range of environments, including flat plates, turbine blade cascade tests and wake-passing experiments. These results were taken at Mach/Reynolds numbers and gas-to-wall temperature ratios representative of gas turbines. Analyses of the spot characteristics are consistent with measurements taken in low speed experiments, and support the Schubauer and Klebanoff type of turbulent spots. The addition of simulated wakes from upstream stages has been observed to be primarily superpositional for these tests.

  16. Poisson's spot and Gouy phase

    NASA Astrophysics Data System (ADS)

    da Paz, I. G.; Soldati, Rodolfo; Cabral, L. A.; de Oliveira, J. G. G.; Sampaio, Marcos

    2016-12-01

    Recently there have been experimental results on Poisson spot matter-wave interferometry followed by theoretical models describing the relative importance of the wave and particle behaviors for the phenomenon. We propose an analytical theoretical model for Poisson's spot with matter waves based on the Babinet principle, in which we use the results for free propagation and single-slit diffraction. We take into account effects of loss of coherence and finite detection area using the propagator for a quantum particle interacting with an environment. We observe that the matter-wave Gouy phase plays a role in the existence of the central peak and thus corroborates the predominantly wavelike character of the Poisson's spot. Our model shows remarkable agreement with the experimental data for deuterium (D2) molecules.

  17. Laser based spot weld characterization

    NASA Astrophysics Data System (ADS)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  18. 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.

  19. Cryogenic systems for the large deployable reflector

    NASA Technical Reports Server (NTRS)

    Mason, Peter V.

    1988-01-01

    There are five technologies which may have application for Large Deployable Reflector (LDR), one passive and four active. In order of maturity, they are passive stored cryogen systems, and mechanical, sorption, magnetic, and pulse-tube refrigerators. In addition, deep space radiators will be required to reject the heat of the active systems, and may be useful as auxiliary coolers for the stored cryogen systems. Hybrid combinations of these technologies may well be more efficient than any one alone, and extensive system studies will be required to determine the best trade-offs. Stored cryogen systems were flown on a number of missions. The systems are capable of meeting the temperature requirements of LDR. The size and weight of stored cryogen systems are proportional to heat load and, as a result, are applicable only if the low-temperature heat load can be kept small. Systems using chemisorption and physical adsorption for compressors and pumps have received considerable attention in the past few years. Systems based on adiabatic demagnetization of paramagnetic salts were used for refrigeration for many years. Pulse-tube refrigerators were recently proposed which show relatively high efficiency for temperatures in the 60 to 80 K range. The instrument heat loads and operating temperatures are critical to the selection and design of the cryogenic system. Every effort should be made to minimize heat loads, raise operating temperatures, and to define these precisely. No one technology is now ready for application to LDR. Substantial development efforts are underway in all of the technologies and should be monitored and advocated. Magnetic and pulse-tube refrigerators have high potential.

  20. 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

  1. Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

    SciTech Connect

    Olson, R. E.; Leeper, R. J.

    2013-09-15

    The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ∼34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid” (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry.

  2. Alternative hot spot formation techniques using liquid deuterium-tritium layer inertial confinement fusion capsules

    SciTech Connect

    Olson, R. E.; Leeper, R. J.

    2013-09-27

    The baseline DT ice layer inertial confinement fusion (ICF) ignition capsule design requires a hot spot convergence ratio of ~34 with a hot spot that is formed from DT mass originally residing in a very thin layer at the inner DT ice surface. In the present paper, we propose alternative ICF capsule designs in which the hot spot is formed mostly or entirely from mass originating within a spherical volume of DT vapor. Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts—the DT wetted hydrocarbon (CH) foam concept and the “fast formed liquid” (FFL) concept—are described and compared to simulations of standard DT ice layer capsules. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low vapor pressure (DT ice) and high vapor pressure (DT liquid) capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules are less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density, with a potentially improved robustness to low-mode x-ray flux asymmetry.

  3. Rocky Mountain spotted fever, Panama.

    PubMed

    Estripeaut, Dora; Aramburú, María Gabriela; Sáez-Llorens, Xavier; Thompson, Herbert A; Dasch, Gregory A; Paddock, Christopher D; Zaki, Sherif; Eremeeva, Marina E

    2007-11-01

    We describe a fatal pediatric case of Rocky Mountain spotted fever in Panama, the first, to our knowledge, since the 1950s. Diagnosis was established by immunohistochemistry, PCR, and isolation of Rickettsia rickettsii from postmortem tissues. Molecular typing demonstrated strong relatedness of the isolate to strains of R. rickettsii from Central and South America.

  4. Hot-spot mix in ignition-scale implosions on the NIF

    SciTech Connect

    Regan, S. P.; Epstein, R.; McCrory, R. L.; Meyerhofer, D. D.; Sangster, T. C.; Hammel, B. A.; Suter, L. J.; Ralph, J.; Scott, H.; Barrios, M. A.; Bradley, D. K.; Callahan, D. A.; Cerjan, C.; Collins, G. W.; Dixit, S. N.; Doeppner, T.; Edwards, M. J.; Farley, D. R.; Glenn, S.; Glenzer, S. H.; and others

    2012-05-15

    Ignition of an inertial confinement fusion (ICF) target depends on the formation of a central hot spot with sufficient temperature and areal density. Radiative and conductive losses from the hot spot can be enhanced by hydrodynamic instabilities. The concentric spherical layers of current National Ignition Facility (NIF) ignition targets consist of a plastic ablator surrounding a thin shell of cryogenic thermonuclear fuel (i.e., hydrogen isotopes), with fuel vapor filling the interior volume [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]. The Rev. 5 ablator is doped with Ge to minimize preheat of the ablator closest to the DT ice caused by Au M-band emission from the hohlraum x-ray drive [D. S. Clark et al., Phys. Plasmas 17, 052703 (2010)]. Richtmyer-Meshkov and Rayleigh-Taylor hydrodynamic instabilities seeded by high-mode () ablator-surface perturbations can cause Ge-doped ablator to mix into the interior of the shell at the end of the acceleration phase [B. A. Hammel et al., Phys. Plasmas 18, 056310 (2011)]. As the shell decelerates, it compresses the fuel vapor, forming a hot spot. K-shell line emission from the ionized Ge that has penetrated into the hot spot provides an experimental signature of hot-spot mix. The Ge emission from tritium-hydrogen-deuterium (THD) and deuterium-tritium (DT) cryogenic targets and gas-filled plastic-shell capsules, which replace the THD layer with a mass-equivalent CH layer, was examined. The inferred amount of hot-spot-mix mass, estimated from the Ge K-shell line brightness using a detailed atomic physics code [J. J. MacFarlane et al., High Energy Density Phys. 3, 181 (2006)], is typically below the 75-ng allowance for hot-spot mix [S. W. Haan et al., Phys. Plasmas 18, 051001 (2011)]. Predictions of a simple mix model, based on linear growth of the measured surface-mass modulations, are consistent with the experimental results.

  5. Cryogenic Detectors (Narrow Field Instruments)

    NASA Astrophysics Data System (ADS)

    Hoevers, H.; Verhoeve, P.

    Two cryogenic imaging spectrometer arrays are currently considered as focal plane instruments for XEUS. The narrow field imager 1 (NFI 1) will cover the energy range from 0.05 to 3 keV with an energy resolution of 2 eV, or better, at 500 eV. A second narrow field imager (NFI 2) covers the energy range from 1 to 15 keV with an energy resolution of 2 eV (at 1 keV) and 5 eV (at 7 keV), creating some overlap with part of the NFI 1 energy window. Both narrow field imagers have a 0.5 arcmin field of view. Their imaging capabilities are matched to the XEUS optics of 2 to 5 arcsec leading to 1 arcsec pixels. The detector arrays will be cooled by a closed cycle system comprising a mechanical cooler with a base temperature of 2.5 K and either a low temperature 3He sorption pump providing the very low temperature stage and/or an Adiabatic Demagnetization Refrigerator (ADR). The ADR cooler is explicitly needed to cool the NFI 2 array. The narrow field imager 1} Currently a 48 times 48 element array of superconducting tunnel junctions (STJ) is envisaged. Its operating temperature is in the range between 30 and 350 mK. Small, single Ta STJs (20-50 mum on a side) have shown 3.5 eV (FWHM) resolution at E = 525 eV and small arrays have been successfully demonstrated (6 times 6 pixels), or are currently tested (10 times 12 pixels). Alternatively, a prototype Distributed Read-Out Imaging Device (DROID), consisting of a linear superconducting Ta absorber of 20 times 100 mum2, including a 20 times 20 mum STJ for readout at either end, has shown a measured energy resolution of 2.4 eV (FWHM) at E = 500 eV. Simulations involving the diffusion properties as well as loss and tunnel rates have shown that the performance can be further improved by slight modifications in the geometry, and that the size of the DROIDS can be increased to 0.5-1.0 mm without loss in energy resolution. The relatively large areas and good energy resolution compared to single STJs make DROIDS good candidates for the

  6. Cryogenic Magnetic Bearing Test Facility (CMBTF)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Cryogenic Magnetic Bearing Test Facility (CMBTF) was designed and built to evaluate compact, lightweight magnetic bearings for use in the SSME's (space shuttle main engine) liquid oxygen and liquid hydrogen turbopumps. State of the art and tradeoff studies were conducted which indicated that a hybrid permanent magnet bias homopolar magnetic bearing design would be smaller, lighter, and much more efficient than conventional industrial bearings. A test bearing of this type was designed for the test rig for use at both room temperature and cryogenic temperature (-320 F). The bearing was fabricated from state-of-the-art materials and incorporated into the CMBTF. Testing at room temperature was accomplished at Avcon's facility. These preliminary tests indicated that this magnetic bearing is a feasible alternative to older bearing technologies. Analyses showed that the hybrid magnetic bearing is one-third the weight, considerably smaller, and uses less power than previous generations of magnetic bearings.

  7. Cryogenic target system for hydrogen layering

    SciTech Connect

    Parham, T.; Kozioziemski, B.; Atkinson, D.; Baisden, P.; Bertolini, L.; Boehm, K; Chernov, A.; Coffee, K.; Coffield, F.; Dylla-Spears, R.; Edwards, O.; Fair, J.; Fedorov, M.; Fry, J.; Gibson, C.; Haid, B.; Holunga, D.; Kohut, T.; Lewis, T.; Malsbury, T.; Mapoles, E.; Sater, J.; Skulina, K.; Trummer, D.; Walters, C.

    2015-11-24

    Here, a cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highly constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.

  8. Low-noise cryogenic transmission line

    NASA Technical Reports Server (NTRS)

    Norris, D.

    1987-01-01

    New low-noise cryogenic input transmission lines have been developed for the Deep Space Network (DSN) at 1.668 GHz for cryogenically cooled Field Effect Transistors (FET) and High Electron Mobility Transistor (HEMT) amplifiers. These amplifiers exhibit very low noise temperatures of 5 K to 15 K, making the requirements for a low-noise input transmission line critical. Noise contribution to the total amplifier system from the low-noise line is less than 0.5 K for both the 1.668-GHz and 2.25-GHz FET systems. The 1.668-GHz input line was installed in six FET systems which were implemented in the DSN for the Venus Balloon Experiment. The 2.25-GHz input line has been implemented in three FET systems for the DSN 34-m HEF antennas, and the design is currently being considered for use at higher frequencies.

  9. Cryogenic fluid management (base R/T): Cryogenic fluid systems, Cryogenic Orbital Nitrogen Experiment (CONE), Cryogenic Orbital Hydrogen Experiment (COHE). (Transportation focused technology)

    NASA Technical Reports Server (NTRS)

    Symons, Pat

    1991-01-01

    The topics presented are covered in viewgraph form. The concluded remarks are: (1) advanced cryogenic fluid systems technology is enhancing or enabling to all known transportation scenarios for space exploration; (2) an integrated/coordinated program involving LeRC/MSFC has been formulated to address all known CFM needs - new needs should they develop, can be accommodated within available skills/facilities; (3) all required/experienced personnel and facilities are finally in place - data from initial ground-based experiments is being collected and analyzed - small scale STS experiments are nearing flight - program is beginning to yield significant results; (4) future proposed funding to primarily come from two sources; and (5) cryogenic fluid experimentation is essential to provide required technology and assure implementation in future NASA missions.

  10. 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.

  11. Designs of pulsed power cryogenic transformers

    SciTech Connect

    Singh, S.K.; Heyne, C.J.; Hackworth, D.T.; Shestak, E.J.; Eckels, P.W.; Rogers, J.D.

    1987-09-01

    The Westinghouse Electric Corporation has completed designs of three pulsed power cryogenic transformers for the Los Alamos National Laboratory. These transformers will be configured to transfer their stored energy sequentially to an electromagnetic launcher and form a three-stage power supply. The pulse transformers will act as two winding energy storage solenoids which provide a high current and energy pulse compression by transforming a 50 kA power supply into a megamp level power supply more appropriate for the electromagnetic launcher duty. This system differs from more traditional transformer applications in that significant current levels do not exist simultaneously in the two windings of the pulse transformer. This paper describes the designs of the pulsed power cryogenic transformers.

  12. Design of the NIF Cryogenic Target System

    SciTech Connect

    Gibson, C; Baltz, J; Malsbury, T; Atkinson, D; Brugmann, V; Coffield, F; Edwards, O; Haid, B; Locke, S; Shiromizu, S; Skulina, K

    2008-06-10

    The United States Department of Energy has embarked on a campaign to conduct credible fusion ignition experiments on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in 2010. The target assembly specified for this campaign requires the formation of a deuterium/tritium (DT) fuel ice layer in a 2 mm diameter capsule at the center of a 9 mm long by 5 mm diameter cylinder, called a hohlraum. The ice layer must be formed and maintained at temperatures below 20 K. At laser shot time, the target is positioned at the center of the NIF target chamber, aligned to the laser beams and held stable to less than 7 {micro}m rms. We have completed the final design of the Cryogenic Target System and are integrating the devices necessary to create, characterize and position the cryogenic target for ignition experiments. These designs, with supporting analysis and prototype test results, will be presented.

  13. Large scale cryogenic fluid systems testing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

  14. Absorber Materials at Room and Cryogenic Temperatures

    SciTech Connect

    F. Marhauser, T.S. Elliott, A.T. Wu, E.P. Chojnacki, E. Savrun

    2011-09-01

    We recently reported on investigations of RF absorber materials at cryogenic temperatures conducted at Jefferson Laboratory (JLab). The work was initiated to find a replacement material for the 2 Kelvin low power waveguide Higher Order Mode (HOM) absorbers employed within the original cavity cryomodules of the Continuous Electron Beam Accelerator Facility (CEBAF). This effort eventually led to suitable candidates as reported in this paper. Furthermore, though constrained by small funds for labor and resources, we have analyzed a variety of lossy ceramic materials, several of which could be usable as HOM absorbers for both normal conducting and superconducting RF structures, e.g. as loads in cavity waveguides and beam tubes either at room or cryogenic temperatures and, depending on cooling measures, low to high operational power levels.

  15. Cryogenic helium 2 systems for space applications

    NASA Technical Reports Server (NTRS)

    Urban, E.; Katz, L.; Hendricks, J.; Karr, G.

    1978-01-01

    Two cryogenic systems are described which will provide cooling for experiments to be flown on Spacelab 2 in the early 1980's. The first system cools a scanning infrared telescope by the transfer of cold helium gas from a separate superfluid helium storage dewar. The flexible design permits the helium storage dewar and transfer assembly to be designed independent of the infrared experiment. Where possible, modified commerical apparatus is used. The second cryogenic system utilizes a specially designed superfluid dewar in which a superfluid helium experiment chamber is immersed. Each dewar system employs a porous plug as a phase separator to hold the liquid helium within the dewar and provide cold gas to a vent line. To maintain the low vapor pressure of the superfluid, each system requires nearly continuous prelaunch vacuum pump service, and each will vent to space during the Spacelab 2 flight.

  16. Design concepts for the ASTROMAG cryogenic system

    NASA Technical Reports Server (NTRS)

    Green, M. A.; Castles, S.

    1988-01-01

    Described is a proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper presents a liquid helium storage concept which would permit cryogenic lifetimes of up to 3 years between refills. It is proposed that the superconducting coil be cooled using superfluid helium pumped by the thermomechanical effect. It is also proposed that the storage tank be resupplied with helium in orbit. A method for charging and discharging the magnet with minimum helium loss using split gas-cooled leads is discussed. A proposal to use a Stirling cycle cryocooler to extend the storage life of the cryostat will also be presented.

  17. 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.

  18. Design concepts for the ASTROMAG cryogenic system

    NASA Technical Reports Server (NTRS)

    Green, M. A.; Castles, S.

    1987-01-01

    Described is a proposed cryogenic system used to cool the superconducting magnet for the Space Station based ASTROMAG Particle Astrophysics Facility. This 2-meter diameter superconducting magnet will be cooled using stored helium II. The paper presents a liquid helium storage concept which would permit cryogenic lifetimes of up to 3 years between refills. It is proposed that the superconducting coil be cooled using superfluid helium pumped by the thermomechanical effect. It is also proposed that the storage tank be resupplied with helium in orbit. A method for charging and discharging the magnet with minimum helium loss using split gas-cooled leads is discussed. A proposal to use a Stirling cycle cryocooler to extend the storage life of the cryostat will also be presented.

  19. Cryogenic hydrogen circulation system of neutron source

    SciTech Connect

    Qiu, Y. N.; Hu, Z. J.; Wu, J. H.; Li, Q.; Zhang, Y.; Zhang, P.; Wang, G. P.

    2014-01-29

    Cold neutron sources of reactors and spallation neutron sources are classic high flux neutron sources in operation all over the world. Cryogenic fluids such as supercritical or supercooled hydrogen are commonly selected as a moderator to absorb the nuclear heating from proton beams. By comparing supercritical hydrogen circulation systems and supercooled hydrogen circulation systems, the merits and drawbacks in both systems are summarized. When supercritical hydrogen circulates as the moderator, severe pressure fluctuations caused by temperature changes will occur. The pressure control system used to balance the system pressure, which consists of a heater as an active controller for thermal compensation and an accumulator as a passive volume controller, is preliminarily studied. The results may provide guidelines for design and operation of other cryogenic hydrogen system for neutron sources under construction.

  20. 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

  1. Cryogenic target system for hydrogen layering

    DOE PAGES

    Parham, T.; Kozioziemski, B.; Atkinson, D.; ...

    2015-11-24

    Here, a cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highlymore » constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.« less

  2. 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.

  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. Optimized Heat Interception for Cryogen Tank Support

    NASA Technical Reports Server (NTRS)

    Canavan, Edgar R.; Miller, F. K.

    2007-01-01

    We consider means for using the cooling available in boil-off gas to intercept heat conducted through the support structure of a cryogen tank. A one-dimensional model of the structure coupled to a gas stream gives an analytical expression for heat leak in terms of flow rate for temperature independent-properties and laminar flow. A numerical model has been developed for heat transfer on a thin cylindrical tube with an attached vent line. The model is used to determine the vent path layout that will minimize heat flow into the cryogen tank. The results are useful for a number of applications, but the one of interest in this study is the minimization of the boil-off in large cryopropellant tanks in low Earth and low lunar orbit.

  5. Progress of the FAIR Cryogenic System

    NASA Astrophysics Data System (ADS)

    Kauschke, M.; Kollmus, H.; Martinez-Lopez, M.

    2017-02-01

    The planning revision of the cryogenic system for the Facility of Antiproton and Ion Research (FAIR, Darmstadt, Germany) resulted in the choice of a single universal plant, which should provide a wide range of cryogenic operation modes, as refrigeration capacity at 4.4K, liquefaction or intermediate temperature levels. The adaptation to the FAIR specific requirements will be done later by adding a second plant. One major demand for the plant is the short term adaptation to variations in the load requirements in the system. An exemplary integration into the overall FAIR system will be shown with the experiments in the Compressed Baryonic Matter (CBM) cave. The CBM cave will house an already existing magnet, HADES, and a new magnet for the CBM experiment, which is still under design. The scheduling of the different operation modes related to the operation of the main consumers as SIS100 or SuperFRS is shown.

  6. Value for controlling flow of cryogenic fluid

    DOEpatents

    Knapp, Philip A.

    1996-01-01

    A valve is provided for accurately controlling the flow of cryogenic fluids such as liquid nitrogen. The valve comprises a combination of disc and needle valves affixed to a valve stem in such a manner that the disc and needle are free to rotate about the stem, but are constrained in lateral and vertical movements. This arrangement provides accurate and precise fluid flow control and positive fluid isolation.

  7. Compensating For Shrinkage In A Cryogenic Seal

    NASA Technical Reports Server (NTRS)

    Hill, Arnold E.

    1993-01-01

    Proposed design for seals in liquid-hydrogen plumbing eliminates leaks caused by contraction of seals at low operating temperature. Each seal consists of rubber, polytetrafluorethylene, or lead O-ring including hollow core filled with water. At temperature of liquid hydrogen, anomalous expansion of water keeps seal gland filled and leaktight despite shrinkage of surrounding O-ring material. Design also used in systems using cryogenic fluids other than liquid hydrogen.

  8. PRESSURE OSCILLATION IN RHIC CRYOGENIC SYSTEM.

    SciTech Connect

    JIA,L.MONTAG,C.TALLERICO,T.HIRZEL,W.NICOLETTI,A.

    2003-09-22

    HORIZONTAL BEAM VIBRATION AROUND 10HZ IN THE RELATIVISTIC HEAVY ION COLLIDER (RHIC) HAVE BEEN IDENTIFIED AND THE POSSIBLE SOURCES TO CAUSE THIS VIBRATION HAVE BEEN INVESTIGATED. TO DETERMINE THE HETIUM PRESSURE OSCILLATIONS AS A POSSIBLE PRIMARY VIBRATION SOURCE, HELIUM PRESSURE MEASUREMENTS WERE CARRIED OUT IN THE FIVE CRYOGENIC TRANSFER LINES AT 2 VALVE BOXES AND 6 LEAD PORTS AT 2 TRIPLET CRYOSTAT FOR BOTH MAGNET RINGS. ADDITIONALLY, COLD MA...

  9. 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.

  10. Cryogen spray cooling during laser tissue welding.

    PubMed

    Fried, N M; Walsh, J T

    2000-03-01

    Cryogen cooling during laser tissue welding was explored as a means of reducing lateral thermal damage near the tissue surface and shortening operative time. Two centimetre long full-thickness incisions were made on the epilated backs of guinea pigs, in vivo. India ink was applied to the incision edges then clamps were used to appose the edges. A 4 mm diameter beam of 16 W, continuous-wave, 1.06 microm, Nd:YAG laser radiation was scanned over the incisions, producing approximately 100 ms pulses. There was a delay of 2 s between scans. The total irradiation time was varied from 1-2 min. Cryogen was delivered to the weld site through a solenoid valve in spurt durations of 20, 60 and 100 ms. The time between spurts was either 2 or 4 s, corresponding to one spurt every one or two laser scans. Histology and tensile strength measurements were used to evaluate laser welds. Total irradiation times were reduced from 10 min without surface cooling to under 1 min with surface cooling. The thermal denaturation profile showed less denaturation in the papillary dermis than in the mid-dermis. Welds created using optimized irradiation and cooling parameters had significantly higher tensile strengths (1.7 +/- 0.4 kg cm(-2)) than measured in the control studies without cryogen cooling (1.0 +/- 0.2 kg cm(-2)) (p < 0.05). Cryogen cooling of the tissue surface during laser welding results in increased weld strengths while reducing thermal damage and operative times. Long-term studies will be necessary to determine weld strengths and the amount of scarring during wound healing.

  11. Method and apparatus for producing cryogenic targets

    DOEpatents

    Murphy, James T.; Miller, John R.

    1984-01-01

    An improved method and apparatus are given for producing cryogenic inertially driven fusion targets in the fast isothermal freezing (FIF) method. Improved coupling efficiency and greater availability of volume near the target for diagnostic purposes and for fusion driver beam propagation result. Other embodiments include a new electrical switch and a new explosive detonator, all embodiments making use of a purposeful heating by means of optical fibers.

  12. Active Control of Cryogenic Propellants in Space

    NASA Technical Reports Server (NTRS)

    Notardonato, William

    2011-01-01

    A new era of space exploration is being planned. Exploration architectures under consideration require the long term storage of cryogenic propellants in space. This requires development of active control systems to mitigate the effect of heat leak. This work summarizes current state of the art, proposes operational design strategies and presents options for future architectures. Scaling and integration of active systems will be estimated. Ideal long range spacecraft systems will be proposed with Exploration architecture benefits considered.

  13. Redesign of the Apollo cryogenic storage system

    NASA Technical Reports Server (NTRS)

    Bouman, C. P.

    1971-01-01

    An assessment of the Apollo 13 mission resulted in establishing new and revised requirements for the design of the oxygen tanks and the associated spacecraft system. Areas discussed include new system requirements, system changes to Apollo 14, revised operational requirements, instrumentation, operational redlines, component isolation modes, and return enhancement capabilities. In order to show the relationship of the cryogenic system to the spacecraft, a short description of the system is presented.

  14. Method and apparatus for producing cryogenic targets

    DOEpatents

    Murphy, J.T.; Miller, J.R.

    1984-08-07

    An improved method and apparatus are given for producing cryogenic inertially driven fusion targets in the fast isothermal freezing (FIF) method. Improved coupling efficiency and greater availability of volume near the target for diagnostic purposes and for fusion driver beam propagation result. Other embodiments include a new electrical switch and a new explosive detonator, all embodiments making use of a purposeful heating by means of optical fibers. 6 figs.

  15. 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.

  16. Cryogenic adhesives and sealants: Abstracted publications

    NASA Technical Reports Server (NTRS)

    Williamson, F. R.; Olien, N. A.

    1977-01-01

    Abstracts of primary documents containing original experimental data on the properties of adhesives and sealants at cryogenic temperatures are presented. The most important references mentioned in each document are cited. In addition, a brief annotation is given for documents considered secondary in nature, such as republications or variations of original reports, progress reports leading to final reports included as primary documents, and experimental data on adhesive properties at temperatures between about 130 K and room temperature.

  17. Superconducting Meissner Effect Bearings for Cryogenic Turbomachines

    DTIC Science & Technology

    1993-05-01

    duration missions, active cryocoolers are under development. These cryocoolers use either Stirling or reverse Brayton cycle refrigerators to cool the focal...Brayton cycle cryocoolers . During this period, a permanent magneWMeissner effect hearing was tested, and a system was developed for measuring the...The program is aimed at the development of a Meissner bearing system for miniature cryogenic turboexpanders used in Brayton cycle cryocoolers . "TIM

  18. Method and apparatus for producing cryogenic targets

    SciTech Connect

    Murphy, J.T.; Miller, J.R.

    1981-08-28

    An improved method and apparatus are given for producing cryogenic inertially driven fusion targets in the fast isothermal freezing (FIF) method. Improved coupling efficiency and greater availability of volume near the target for diagnostic purposes and for fusion driver beam propagation result. Other embodiments include a new electrical switch and a new explosive detonator, all embodiments making use of a purposeful heating by means of optical fibers.

  19. Cryogenic regenerator including sarancarbon heat conduction matrix

    NASA Technical Reports Server (NTRS)

    Jones, Jack A. (Inventor); Petrick, S. Walter (Inventor); Britcliffe, Michael J. (Inventor)

    1989-01-01

    A saran carbon matrix is employed to conduct heat through the heat storing volume of a cryogenic regenerator. When helium is adsorbed into the saran carbon matrix, the combination exhibits a volumetric specific heat much higher than previously used lead balls. A helium adsorbed saran regenerator should allow much lower refrigerator temperatures than those practically obtainable with lead based regenerators for regenerator type refrigeration systems.

  20. Terrestrial Planet Finder cryogenic delay line development

    NASA Technical Reports Server (NTRS)

    Smythe, Robert F.; Swain, Mark R.; Alvarez-Salazar, Oscar; Moore, James D.

    2004-01-01

    Delay lines provide the path-length compensation that makes the measurement of interference fringes possible. When used for nulling interferometry, the delay line must control path-lengths so that the null is stable and controlled throughout the measurement. We report on a low noise, low disturbance, and high bandwidth optical delay line capable of meeting the TPF interferometer optical path length control requirements at cryogenic temperatures.

  1. 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.

  2. 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.

  3. 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.

  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. Sensor and Instrumentation Development for Cryogenic Detectors

    NASA Astrophysics Data System (ADS)

    Allen, Nicholas; Febbraro, Micheal; Pain, Steven; Aidala, Christine; Lesser, Ezra; White, Aaron

    2015-10-01

    In the study of nuclear science, there is an ever increasing need for better efficiency and resolution in In nuclear sciences, new detectors with improved detection efficiency and energy resolution are constantly needed to drive experimental discovery and accuracy. Certain cryogenic liquids, particularly liquid noble gases such as Argon and Xenon, are very sensitive to energy deposited by ionizing particles and have many other useful properties for detector development. Developing these cryogenic liquids to operate with known detection methods offers exciting opportunities for experimental setups and has a wide variety of uses with regards to nuclear studies, such as gamma ray, neutron, and neutrino detection. However, operating at such low temperatures presents many complications when trying to effectively control and maintain detectors. In this poster, I will present some of the equipment and systems developed for particular low temperature applications. This will include the use of platinum resistance thermometers, capacitance-based liquid level sensors, and various systems used to regulate fluid flow for cryogenic detector systems.

  7. Safety Aspects of Big Cryogenic Systems Design

    NASA Astrophysics Data System (ADS)

    Chorowski, M.; Fydrych, J.; Poliński, J.

    2010-04-01

    Superconductivity and helium cryogenics are key technologies in the construction of large scientific instruments, like accelerators, fusion reactors or free electron lasers. Such cryogenic systems may contain more than hundred tons of helium, mostly in cold and high-density phases. In spite of the high reliability of the systems, accidental loss of the insulation vacuum, pipe rupture or rapid energy dissipation in the cold helium can not be overlooked. To avoid the danger of over-design pressure rise in the cryostats, they need to be equipped with a helium relief system. Such a system is comprised of safety valves, bursting disks and optionally cold or warm quench lines, collectors and storage tanks. Proper design of the helium safety relief system requires a good understanding of worst case scenarios. Such scenarios will be discussed, taking into account different possible failures of the cryogenic system. In any case it is necessary to estimate heat transfer through degraded vacuum superinsulation and mass flow through the valves and safety disks. Even if the design of the helium relief system does not foresee direct helium venting into the environment, an occasional emergency helium spill may happen. Helium propagation in the atmosphere and the origins of oxygen-deficiency hazards will be discussed.

  8. Temperature Stratification in a Cryogenic Fuel Tank

    NASA Technical Reports Server (NTRS)

    Daigle, Matthew John; Smelyanskiy, Vadim; Boschee, Jacob; Foygel, Michael Gregory

    2013-01-01

    A reduced dynamical model describing temperature stratification effects driven by natural convection in a liquid hydrogen cryogenic fuel tank has been developed. It accounts for cryogenic propellant loading, storage, and unloading in the conditions of normal, increased, and micro- gravity. The model involves multiple horizontal control volumes in both liquid and ullage spaces. Temperature and velocity boundary layers at the tank walls are taken into account by using correlation relations. Heat exchange involving the tank wall is considered by means of the lumped-parameter method. By employing basic conservation laws, the model takes into consideration the major multi-phase mass and energy exchange processes involved, such as condensation-evaporation of the hydrogen, as well as flows of hydrogen liquid and vapor in the presence of pressurizing helium gas. The model involves a liquid hydrogen feed line and a tank ullage vent valve for pressure control. The temperature stratification effects are investigated, including in the presence of vent valve oscillations. A simulation of temperature stratification effects in a generic cryogenic tank has been implemented in Matlab and results are presented for various tank conditions.

  9. 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.

  10. NTF: Soldering Technology Development for Cryogenics

    NASA Technical Reports Server (NTRS)

    Hall, E. T., Jr.

    1985-01-01

    The advent of the National Transonic Facility (NTF) brought about a new application for an old joining method, soldering. Soldering for use at cryogenic temperatures requires that solders remain ductile and free from tin-pest (grey tin), have toughness to withstand aerodynamic loads associated with flight research, and maintain their surface finishes. Solders are used to attach 347 Stainless-Steel tubing in surface grooves of models. The solder must fill up the gap and metallurgically bound to the tubing and model. Cryogenic temperatures require that only specific materials for models can be used, including: Vasco Max 200 CVM, lescalloy A-286 Vac Arc, pH 13-8 Mo. Solders identified for testing at this time are: 50% Sn - 49.5% Pb - 0.5% Sb, 95% Sn - 5% Sb, 50% In 50% Pb, and 37.5% Sn - 37.5% Pb - 25% In. With these materials and solders, it is necessary to determine their solderability. After solderability is determined, tube/groove specimens are fabricated and stressed under cryogenic temperatures. Compatible solders are then used for acutual models.

  11. Material Damping Experiments at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Levine, Marie; White, Christopher

    2003-01-01

    A unique experimental facility has been designed to measure damping of materials at cryogenic temperatures. The test facility pays special attention to removing other sources of damping in the measurement by avoiding frictional interfaces, decoupling the test specimen from the support system, and by using a non-contacting measurement device; Damping data is obtained for materials (AI, GrEp, Be, Fused Quartz), strain amplitudes (less than 10-6 ppm), frequencies (20Hz-330Hz) and temperatures (20K-293K) relevant to future precision optical space missions. The test data shows a significant decrease in viscous damping at cryogenic temperatures and can be as low as 10-4%, but the amount of the damping decrease is a function of frequency and material. Contrary to the other materials whose damping monotonically decreased with temperature, damping of Fused Quartz increased substantially at cryo, after reaching a minimum at around l50 K. The damping is also shown to be insensitive to strain for low strain levels. At room temperatures, the test data correlates well to the analytical predictions of the Zener damping model. Discrepancies at cryogenic temperatures between the model predictions and the test data are observed.

  12. Miniature thermo-electric cooled cryogenic pump

    DOEpatents

    Keville, R.F.

    1997-11-18

    A miniature thermo-electric cooled cryogenic pump is described for removing residual water molecules from an inlet sample prior to sample analysis in a mass spectroscopy system, such as ion cyclotron resonance (ICR) mass spectroscopy. The cryogenic pump is a battery operated, low power (<1.6 watts) pump with a {Delta}T=100 C characteristic. The pump operates under vacuum pressures of 5{times}10{sup {minus}4} Torr to ultra high vacuum (UHV) conditions in the range of 1{times}10{sup {minus}7} to 3{times}10{sup {minus}9} Torr and will typically remove partial pressure, 2{times}10{sup {minus}7} Torr, residual water vapor. The cryogenic pump basically consists of an inlet flange piece, a copper heat sink with a square internal bore, four two tier Peltier (TEC) chips, a copper low temperature square cross sectional tubulation, an electronic receptacle, and an exit flange piece, with the low temperature tubulation being retained in the heat sink at a bias angle of 5{degree}, and with the TECs being positioned in parallel to each other with a positive potential being applied to the top tier thereof. 2 figs.

  13. Miniature thermo-electric cooled cryogenic pump

    DOEpatents

    Keville, Robert F.

    1997-01-01

    A miniature thermo-electric cooled cryogenic pump for removing residual water molecules from an inlet sample prior to sample analysis in a mass spectroscopy system, such as ion cyclotron resonance (ICR) mass spectroscopy. The cryogenic pump is a battery operated, low power (<1.6 watts) pump with a .DELTA.T=100.degree. C. characteristic. The pump operates under vacuum pressures of 5.times.10.sup.-4 Torr to ultra high vacuum (UHV) conditions in the range of 1.times.10.sup.-7 to 3.times.10.sup.-9 Torr and will typically remove partial pressure, 2.times.10.sup.-7 Torr, residual water vapor. The cryogenic pump basically consists of an inlet flange piece, a copper heat sink with a square internal bore, four two tier Peltier (TEC) chips, a copper low temperature square cross sectional tubulation, an electronic receptacle, and an exit flange piece, with the low temperature tubulation being retained in the heat sink at a bias angle of 5.degree., and with the TECs being positioned in parallel to each other with a positive potential being applied to the top tier thereof.

  14. Expandable Purge Chambers Would Protect Cryogenic Fittings

    NASA Technical Reports Server (NTRS)

    Townsend, Ivan I., III

    2004-01-01

    Expandable ice-prevention and cleanliness-preservation (EIP-CP) chambers have been proposed to prevent the accumulation of ice or airborne particles on quick-disconnect (QD) fittings, or on ducts or tubes that contain cryogenic fluids. In the original application for which the EIP-CP chambers were conceived, there is a requirement to be able to disconnect and reconnect the QD fittings in rapid succession. If ice were to form on the fittings by condensation and freezing of airborne water vapor on the cold fitting surfaces, the ice could interfere with proper mating of the fittings, making it necessary to wait an unacceptably long time for the ice to thaw before attempting reconnection. By keeping water vapor away from the cold fitting surfaces, the EIP-CP chambers would prevent accumulation of ice, preserving the ability to reconnect as soon as required. Basically, the role of an EIP-CP chamber would be to serve as an enclosure for a flow of dry nitrogen gas that would keep ambient air away from QD cryogenic fittings. An EIP-CP chamber would be an inflatable device made of a fabriclike material. The chamber would be attached to an umbilical plate holding a cryogenic QD fitting.

  15. Thermoelectric Generators used as Cryogenic Heat Engines

    NASA Astrophysics Data System (ADS)

    Smith, D. E.; Ordonez, C. A.

    1997-03-01

    A future experiment is being planned at the University of North Texas to design, build, and test a cryogenic heat engine(C. A. Ordonez, Am. J. Phys. 64), 479 (1996). suitable as an electric-vehicle power system. The power system shall then be installed in a demonstration vehicle. This will be a next-generation vehicle following the current project described in the accompanying poster, ``Experimental Car Which Uses Liquid Nitrogen as Its Fuel" by M. E. Parker et al. The cryogenic heat engine electric vehicle power system will incorporate both a thermoelectric generator and an ambient-temperature turbine or pneumatic-motor/generator. The thermoelectric generator shall use liquid nitrogen (under pressure) as its cold reservoir. Energy is produced with the thermoelectric generator by using the liquid/gas phase change to absorb heat. At the present time a study is being carried out to determine the efficiency of thermoelectric devices which are used as cryogenic heat engines. Initial data is being taken using frozen H_2O and CO2 as cold reservoirs. The results of the study shall be presented.

  16. 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.

  17. 9 CFR 149.4 - Spot audit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random...

  18. 9 CFR 149.4 - Spot audit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Spot audit. 149.4 Section 149.4... LIVESTOCK IMPROVEMENT VOLUNTARY TRICHINAE CERTIFICATION PROGRAM § 149.4 Spot audit. (a) In addition to regularly scheduled site audits, certified production sites will be subject to spot audits. (1) Random...

  19. Rapid-Chill Cryogenic Coaxial Direct-Acting Solenoid Valve

    NASA Technical Reports Server (NTRS)

    Richard, James; Castor, Jim; Sheller, Richard

    2006-01-01

    A commercially available cryogenic direct- acting solenoid valve has been modified to incorporate a rapid-chill feature. The net effect of the modifications is to divert some of the cryogenic liquid to the task of cooling the remainder of the cryogenic liquid that flows to the outlet. Among the modifications are the addition of several holes and a gallery into a valve-seat retainer and the addition of a narrow vent passage from the gallery to the atmosphere.

  20. Some General Principles in Cryogenic Design, Implementation, and Testing

    NASA Technical Reports Server (NTRS)

    Dipirro, Michael James

    2015-01-01

    Brief Course Description: In 2 hours only the most basic principles of cryogenics can be presented. I will concentrate on the differences between a room temperature thermal analysis and cryogenic thermal analysis, namely temperature dependent properties. I will talk about practical materials for thermal contact and isolation. I will finish by describing the verification process and instrumentation used that is unique to cryogenic (in general less than 100K) systems.

  1. Historical Summary of Cryogenic Activity Prior to 1950

    NASA Astrophysics Data System (ADS)

    Radebaugh, R.

    Cryogenics is the science and technology dealing with temperatures less than about 120 K, although this historical summary does not adhere to a strict 120 K definition. The techniques used to produce cryogenic temperatures differ in severalways from those dealing with conventional refrigeration. In practice, these two areas often overlap and the boundary between conventional and cryogenic refrigeration is often indistinct. Significant reductions in temperature often have very pronounced effects on the properties of materials and the behavior of systems.

  2. Managing Rocky Mountain spotted fever.

    PubMed

    Minniear, Timothy D; Buckingham, Steven C

    2009-11-01

    Rocky Mountain spotted fever is caused by the tick-borne bacterium Rickettsia rickettsii. Symptoms range from moderate illness to severe illness, including cardiovascular compromise, coma and death. The disease is prevalent in most of the USA, especially during warmer months. The trademark presentation is fever and rash with a history of tick bite, although tick exposure is unappreciated in over a third of cases. Other signature symptoms include headache and abdominal pain. The antibiotic therapy of choice for R. rickettsii infection is doxycycline. Preventive measures for Rocky Mountain spotted fever and other tick-borne diseases include: wearing long-sleeved, light colored clothing; checking for tick attachment and removing attached ticks promptly; applying topical insect repellent; and treating clothing with permethrin.

  3. Sweet Spots and Door Stops

    ERIC Educational Resources Information Center

    Thompson, Michael; Tsui, Stella; Leung, Chi Fan

    2011-01-01

    A sweet spot is referred to in sport as the perfect place to strike a ball with a racquet or bat. It is the point of contact between bat and ball where maximum results can be produced with minimal effort from the hand of the player. Similar physics can be applied to the less inspiring examples of door stops; the perfect position of a door stop is…

  4. Integrated modeling of cryogenic layered highfoot experiments at the NIF

    NASA Astrophysics Data System (ADS)

    Kritcher, A. L.; Hinkel, D. E.; Callahan, D. A.; Hurricane, O. A.; Clark, D.; Casey, D. T.; Dewald, E. L.; Dittrich, T. R.; Döppner, T.; Barrios Garcia, M. A.; Haan, S.; Berzak Hopkins, L. F.; Jones, O.; Landen, O.; Ma, T.; Meezan, N.; Milovich, J. L.; Pak, A. E.; Park, H.-S.; Patel, P. K.; Ralph, J.; Robey, H. F.; Salmonson, J. D.; Sepke, S.; Spears, B.; Springer, P. T.; Thomas, C. A.; Town, R.; Celliers, P. M.; Edwards, M. J.

    2016-05-01

    Integrated radiation hydrodynamic modeling in two dimensions, including the hohlraum and capsule, of layered cryogenic HighFoot Deuterium-Tritium (DT) implosions on the NIF successfully predicts important data trends. The model consists of a semi-empirical fit to low mode asymmetries and radiation drive multipliers to match shock trajectories, one dimensional inflight radiography, and time of peak neutron production. Application of the model across the HighFoot shot series, over a range of powers, laser energies, laser wavelengths, and target thicknesses predicts the neutron yield to within a factor of two for most shots. The Deuterium-Deuterium ion temperatures and the DT down scattered ratios, ratio of (10-12)/(13-15) MeV neutrons, roughly agree with data at peak fuel velocities <340 km/s and deviate at higher peak velocities, potentially due to flows and neutron scattering differences stemming from 3D or capsule support tent effects. These calculations show a significant amount alpha heating, 1-2.5× for shots where the experimental yield is within a factor of two, which has been achieved by increasing the fuel kinetic energy. This level of alpha heating is consistent with a dynamic hot spot model that is matched to experimental data and as determined from scaling of the yield with peak fuel velocity. These calculations also show that low mode asymmetries become more important as the fuel velocity is increased, and that improving these low mode asymmetries can result in an increase in the yield by a factor of several.

  5. Comparison of Hot Spot Formation in DT ice layer and DT liquid layer ICF Capsules

    NASA Astrophysics Data System (ADS)

    Olson, R. E.; Leeper, R. J.

    2013-10-01

    Simulations of the implosion and hot spot formation in two DT liquid layer ICF capsule concepts - the DT wetted CH foam concept and the ``fast formed liquid'' (FFL) concept - will be described and compared to simulations of standard DT ice layer capsules. The wetted foam and FFL designs allow for flexibility in hot spot convergence ratio through the adjustment of the initial cryogenic capsule temperature and, hence, DT vapor density. 1D simulations are used to compare the drive requirements, the optimal shock timing, the radial dependence of hot spot specific energy gain, and the hot spot convergence ratio in low (DT ice) and high (DT liquid) vapor pressure capsules. 2D simulations are used to compare the relative sensitivities to low-mode x-ray flux asymmetries in the DT ice and DT liquid capsules. It is found that the overall thermonuclear yields predicted for DT liquid layer capsules will be less than yields predicted for DT ice layer capsules in simulations using comparable capsule size and absorbed energy. However, the relative simplicity of the hot spot formation technique might lead to a more robust ignition experiment, a reduction in sensitivity to low-mode x-ray flux asymmetry, and an improvement in the computational prediction of hot spot behavior. This work was performed under the auspices of the U. S. DOE by LANL under contract DE-AC52-06NA25396. Sandia is a multiprogram laboratory operated by the Sandia Corporation, a Lockheed-Martin Company, for the U.S. DOE under contract DE-AC04-94AL85000.

  6. 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.

  7. 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.

  8. 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.

  9. Investigation of woven composites as potential cryogenic tank materials

    NASA Astrophysics Data System (ADS)

    Islam, Md. S.; Melendez-Soto, E.; Castellanos, A. G.; Prabhakar, P.

    2015-12-01

    In this paper, carbon fiber and Kevlar® fiber woven composites were investigated as potential cryogenic tank materials for storing liquid fuel in spacecraft or rocket. Towards that end, both carbon and Kevlar® fiber composites were manufactured and tested with and without cryogenic exposure. The focus was on the investigation of the influence of initial cryogenic exposure on the degradation of the composite. Tensile, flexural and inter laminar shear strength (ILSS) tests were conducted, which indicate that Kevlar® and carbon textile composites are potential candidates for use under cryogenic exposure.

  10. Absorption-Desorption Compressor for Spaceborne/Airborne Cryogenic Refrigerators.

    DTIC Science & Technology

    Refrigerant compressors, *Refrigeration systems), Spaceborne, Airborne, Cryogenics, Gases, Absorption, Desorption, Hydrogen, Hydrides, Lanthanum compounds, Nickel alloys, Joule Thomson effect , Heat transfer

  11. 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.

  12. Justifications shape ethical blind spots.

    PubMed

    Pittarello, Andrea; Leib, Margarita; Gordon-Hecker, Tom; Shalvi, Shaul

    2015-06-01

    To some extent, unethical behavior results from people's limited attention to ethical considerations, which results in an ethical blind spot. Here, we focus on the role of ambiguity in shaping people's ethical blind spots, which in turn lead to their ethical failures. We suggest that in ambiguous settings, individuals' attention shifts toward tempting information, which determines the magnitude of their lies. Employing a novel ambiguous-dice paradigm, we asked participants to report the outcome of the die roll appearing closest to the location of a previously presented fixation cross on a computer screen; this outcome would determine their pay. We varied the value of the die second closest to the fixation cross to be either higher (i.e., tempting) or lower (i.e., not tempting) than the die closest to the fixation cross. Results of two experiments revealed that in ambiguous settings, people's incorrect responses were self-serving. Tracking participants' eye movements demonstrated that people's ethical blind spots are shaped by increased attention toward tempting information.

  13. Systematic Propulsion Optimization Tools (SPOT)

    NASA Technical Reports Server (NTRS)

    Bower, Mark; Celestian, John

    1992-01-01

    This paper describes a computer program written by senior-level Mechanical Engineering students at the University of Alabama in Huntsville which is capable of optimizing user-defined delivery systems for carrying payloads into orbit. The custom propulsion system is designed by the user through the input of configuration, payload, and orbital parameters. The primary advantages of the software, called Systematic Propulsion Optimization Tools (SPOT), are a user-friendly interface and a modular FORTRAN 77 code designed for ease of modification. The optimization of variables in an orbital delivery system is of critical concern in the propulsion environment. The mass of the overall system must be minimized within the maximum stress, force, and pressure constraints. SPOT utilizes the Design Optimization Tools (DOT) program for the optimization techniques. The SPOT program is divided into a main program and five modules: aerodynamic losses, orbital parameters, liquid engines, solid engines, and nozzles. The program is designed to be upgraded easily and expanded to meet specific user needs. A user's manual and a programmer's manual are currently being developed to facilitate implementation and modification.

  14. Sensitivity of Inferred Electron Temperature from X-ray Emission of NIF Cryogenic DT Implosions

    SciTech Connect

    Klem, Michael

    2015-05-01

    The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory seeks to achieve thermonuclear ignition through inertial confinement fusion. The accurate assessment of the performance of each implosion experiment is a crucial step. Here we report on work to derive a reliable electron temperature for the cryogenic deuteriumtritium implosions completed on the NIF using the xray signal from the Ross filter diagnostic. These Xrays are dominated by bremsstrahlung emission. By fitting the xray signal measured through each of the individual Ross filters, the source bremsstrahlung spectrum can be inferred, and an electron temperature of the implosion hot spot inferred. Currently, each filter is weighted equally in this analysis. We present work quantifying the errors with such a technique and the results from investigating the contribution of each filter to the overall accuracy of the temperature inference. Using this research, we also compare the inferred electron temperature against other measured implosion quantities to develop a more complete understanding of the hotspot physics.

  15. Fiber-optic Bragg grating sensors for structural health monitoring at cryogenic temperatures

    NASA Astrophysics Data System (ADS)

    Ecke, Wolfgang; Latka, Ines; Habisreuther, Tobias; Lingertat, Johann

    2007-04-01

    While conventional resistance strain gages show increasing cross-sensitivities to temperature and magnetic field with decreasing temperature down to liquid helium, it has been found that fiber optic Bragg grating strain sensors show negligible thermo-optic and magneto-optic effects in cryogenic environment and allow, therefore, reliable strain measurements. These specific application advantages of optical fiber Bragg grating sensors at low temperatures, together with the electrical isolation and low electro-magnetic interference, low thermal conductivity to a large number of multiplexed sensors, make them attractive for structural health monitoring of super-conductive magnets, e.g., for super-conductive motors, magnetic levitation transport, nuclear fusion reactors, or for measurement of material parameters at low temperature, and, if using special sensor substrates, also for temperature measurements and hot spot detection on superconductors.

  16. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-01

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ˜16 m to a streak camera in a well-shielded location. An ˜200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ˜40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  17. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    SciTech Connect

    Stoeckl, C.; Boni, R.; Ehrne, F.; Forrest, C. J.; Glebov, V. Yu.; Katz, J.; Lonobile, D. J.; Magoon, J.; Regan, S. P.; Shoup, III, M. J.; Sorce, A.; Sorce, C.; Sangster, T. C.; Weiner, D.

    2016-05-10

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic DT implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ~16 m to a streak camera in a well-shielded location. An ~200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ~40±10 ps was measured in a dedicated experiment using hard x rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. Furthermore, the measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  18. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA.

    PubMed

    Stoeckl, C; Boni, R; Ehrne, F; Forrest, C J; Glebov, V Yu; Katz, J; Lonobile, D J; Magoon, J; Regan, S P; Shoup, M J; Sorce, A; Sorce, C; Sangster, T C; Weiner, D

    2016-05-01

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments-a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ∼16 m to a streak camera in a well-shielded location. An ∼200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ∼40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

  19. Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

    DOE PAGES

    Stoeckl, C.; Boni, R.; Ehrne, F.; ...

    2016-05-10

    A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic DT implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments—a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ~16 m to a streak camera in amore » well-shielded location. An ~200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ~40±10 ps was measured in a dedicated experiment using hard x rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. Furthermore, the measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.« less

  20. Downstream Development of a Laminar Spot

    NASA Astrophysics Data System (ADS)

    Sekiya, Naoki; Matsumoto, Akira

    It was well-known that a disturbance, introduced artificially into a supercritical laminar boundary layer along a flat plate, is still laminar in the initial stage of its downstream development. Thus, we named it a "laminar spot" because it resembles a turbulent spot though its velocity perturbation remains laminar. From velocity measurements using a rake-type 16-channel hot-wire probe, we found that in the first stage of the downstream development of a laminar spot, its maximum width was at 0.2δ (what is called the critical layer) and one-half of its lateral growth angle was about 5°, which is almost one-half that of a turbulent spot. We call this region a "laminar spot region". In the present study, we measured in detail the velocity field of a laminar spot using a new hot-wire probe in the laminar spot region. The results showed that a laminar spot consists of some hairpin vortices and some induced U-shaped vortices under the hairpin vortices. Because of the interaction of the velocities induced by the respective vortex legs, the legs of the U-shaped vortices were located at the outermost part of the spot. Moreover, the new vortex legs extended spanwise at about 4° as the spot traveled downstream. Consequently, we concluded that the laminar spot grew spanwise in accordance with the span of these vortex legs.

  1. ESA uncovers Geminga's `hot spot'

    NASA Astrophysics Data System (ADS)

    2004-07-01

    16 July 2004 Astronomers using ESA’s X-ray observatory XMM-Newton have detected a small, bright ‘hot spot’ on the surface of the neutron star called Geminga, 500 light-years away. The hot spot is the size of a football field and is caused by the same mechanism producing Geminga’s X-ray tails. This discovery identifies the missing link between the X-ray and gamma-ray emission from Geminga. hi-res Size hi-res: 1284 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot This figure shows the effects of charged particles accelerated in the magnetosphere of Geminga. Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of particles kicked out by Geminga’s strong magnetic field, trail the neutron star as it moves about in space. Panel (b) shows how electrically charged particles interact with Geminga’s magnetic field. For example, if electrons (blue) are kicked out by the star, positrons (in red) hit the star’s magnetic poles like in an ‘own goal’. Panel (c) illustrates the size of Geminga’s magnetic field (blue) compared to that of the star itself at the centre (purple). The magnetic field is tilted with respect to Geminga’s rotation axis (red). Panel (d) shows the magnetic poles of Geminga, where charged particles hit the surface of the star, creating a two-million degrees hot spot, a region much hotter than the surroundings. As the star spins on its rotation axis, the hot spot comes into view and then disappears, causing the periodic colour change seen by XMM-Newton. An animated version of the entire sequence can be found at: Click here for animated GIF [low resolution, animated GIF, 5536 KB] Click here for AVI [high resolution, AVI with DIVX compression, 19128 KB] hi-res Size hi-res: 371 kb Credits: ESA, P. Caraveo (IASF, Milan) Geminga's hot spot, panel (a) Panel (a) shows an image taken with the EPIC instrument on board the XMM-Newton observatory. The bright tails, made of

  2. 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

    International Conference ICEC 26 - ICMC 2016 was organized at New Delhi, India during March 7-11, 2016. Previous conference ICEC25-ICMC 2014 was held at the University of Twente, The Netherlands in July 2014. Next Conference ICEC 27- ICMC 2018 will be held at Oxford, UK during September 3-7, 2018 1. Introduction This is a biennial international conference on cryogenic engineering and cryogenics materials organized by the International Cryogenic Engineering Committee and the International Cryogenic Material Committee. For some years, the host country has been alternating between Europe and Asia. The present conference was held at the Manekshaw Convention Centre, New Delhi, India during March 7-11, 2016 and hosted jointly by the Indian Cryogenics Council (ICC) and the Inter-University Accelerator Centre (IUAC), New Delhi. Put all together as many as 547 persons participated in the conference. Out of these 218 were foreign delegates coming from 25 countries and the rest from India. 2. Inaugural Session & Course Lectures The pre conference short course lectures on “Cryocoolers” and “Superconducting Materials for Power Applications” were organized on 7th March. Cryocooler course was given jointly by Dr. Chao Wang from M/s. Cryomech, USA and Prof. Milind Atrey from IIT Bombay, India. The Course on Superconducting Materials was given by Prof. Venkat Selvamanickam from the University of Houston, USA. The conference was inaugurated in the morning of March 8th in a typical Indian tradition and in the presence of the Chief Guest, Dr. R Chidambaram (Principle Scientific Adviser to Govt. of India), Guest of Honour, Prof. H Devaraj (Vice Chairman University Grant Commission), Prof Marcel ter Brake ( Chair, ICEC Board), Prof. Wilfried Goldacker (Chair, ICMC board), Dr. D Kanjilal (Director IUAC), Dr R K Bhandari, (President, Indian Cryogenic Council ). Dr. T S Datta, Chair Local Organizing Committee coordinated the proceedings of the inaugural function. 3. Technical

  3. Watermarking spot colors in packaging

    NASA Astrophysics Data System (ADS)

    Reed, Alastair; Filler, TomáÅ.¡; Falkenstern, Kristyn; Bai, Yang

    2015-03-01

    In January 2014, Digimarc announced Digimarc® Barcode for the packaging industry to improve the check-out efficiency and customer experience for retailers. Digimarc Barcode is a machine readable code that carries the same information as a traditional Universal Product Code (UPC) and is introduced by adding a robust digital watermark to the package design. It is imperceptible to the human eye but can be read by a modern barcode scanner at the Point of Sale (POS) station. Compared to a traditional linear barcode, Digimarc Barcode covers the whole package with minimal impact on the graphic design. This significantly improves the Items per Minute (IPM) metric, which retailers use to track the checkout efficiency since it closely relates to their profitability. Increasing IPM by a few percent could lead to potential savings of millions of dollars for retailers, giving them a strong incentive to add the Digimarc Barcode to their packages. Testing performed by Digimarc showed increases in IPM of at least 33% using the Digimarc Barcode, compared to using a traditional barcode. A method of watermarking print ready image data used in the commercial packaging industry is described. A significant proportion of packages are printed using spot colors, therefore spot colors needs to be supported by an embedder for Digimarc Barcode. Digimarc Barcode supports the PANTONE spot color system, which is commonly used in the packaging industry. The Digimarc Barcode embedder allows a user to insert the UPC code in an image while minimizing perceptibility to the Human Visual System (HVS). The Digimarc Barcode is inserted in the printing ink domain, using an Adobe Photoshop plug-in as the last step before printing. Since Photoshop is an industry standard widely used by pre-press shops in the packaging industry, a Digimarc Barcode can be easily inserted and proofed.

  4. Polyamide 66 as a Cryogenic Dielectric

    SciTech Connect

    Tuncer, Enis; Polyzos, Georgios; Sauers, Isidor; James, David Randy; Ellis, Alvin R; Messman, Jamie M; Aytug, Tolga

    2009-01-01

    Improvements in superconductor and cryogenic technologies enable novel power apparatus, \\eg, cables, transformers, fault current limiters, generators, \\etc, with better device characteristics than their conventional counterparts. In these applications electrical insulation materials play an important role in system weight, footprint (size), and voltage level. The trend in the electrical insulation material selection has been to adapt or to employ conventional insulation materials to these new systems. However, at low temperatures, thermal contraction and loss of mechanical strength in many materials make them unsuitable for superconducting power applications. In this paper, a widely used commercial material was characterized as a potential cryogenic dielectric. The material is used in ``oven bag'' a heat-resistant polyamide (nylon) used in cooking (produced by Reynolds\\textregistered, Richmond, VA, USA). It is first characterized by Fourier transform infrared and x-ray diffraction techniques and determined to be composed of polyamide 66 (PA66) polymer. Secondly the complex dielectric permittivity and dielectric breakdown strength of the PA66 films are investigated. The dielectric data are then compared with data reported in the literature. A comparison of dielectric strength with a widely used high-temperature superconductor electrical insulation material, polypropylene-laminated paper (PPLP\\texttrademark\\ a product of Sumitomo Electric Industries, Japan), is provided. It is observed that the statistical analysis of the PA66 films yields 1\\% failure probability at $127\\ \\kilo\\volt\\milli\\meter^{-1}$; this value is approximately $46\\ \\kilo\\volt\\milli\\meter^{-1}$ higher than PPLP\\texttrademark. It is concluded that PA66 may be a good candidate for cryogenic applications. Finally, a summary of dielectric properties of some of the commercial tape insulation materials and various polymers is also provided.

  5. Cryogenic Scan Mechanism for Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Brasunas, John C.; Francis, John L.

    2011-01-01

    A compact and lightweight mechanism has been developed to accurately move a Fourier transform spectrometer (FTS) scan mirror (a cube corner) in a near-linear fashion with near constant speed at cryogenic temperatures. This innovation includes a slide mechanism to restrict motion to one dimension, an actuator to drive the motion, and a linear velocity transducer (LVT) to measure the speed. The cube corner mirror is double-passed in one arm of the FTS; double-passing is required to compensate for optical beam shear resulting from tilting of the moving cube corner. The slide, actuator, and LVT are off-the-shelf components that are capable of cryogenic vacuum operation. The actuator drives the slide for the required travel of 2.5 cm. The LVT measures translation speed. A proportional feedback loop compares the LVT voltage with the set voltage (speed) to derive an error signal to drive the actuator and achieve near constant speed. When the end of the scan is reached, a personal computer reverses the set voltage. The actuator and LVT have no moving parts in contact, and have magnetic properties consistent with cryogenic operation. The unlubricated slide restricts motion to linear travel, using crossed roller bearings consistent with 100-million- stroke operation. The mechanism tilts several arc seconds during transport of the FTS mirror, which would compromise optical fringe efficiency when using a flat mirror. Consequently, a cube corner mirror is used, which converts a tilt into a shear. The sheared beam strikes (at normal incidence) a flat mirror at the end of the FTS arm with the moving mechanism, thereby returning upon itself and compensating for the shear

  6. 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.

  7. R&D ERL: Cryogenic System

    SciTech Connect

    Than, R.

    2010-01-01

    The ERL cryogenic system will supply cooling to a super-conducting RF (SCRF) gun and the 5-cell super-conducting RF cavity system that need to be held cold at 2K. The engineering of the cavity cryomodules were carried out by AES in collaboration with BNL. The 2K superfluid bath is produced by pumping on the bath using a sub-atmospheric warm compression system. The cryogenic system makes use of mainly existing equipment relocated from other facilities: a 300W 4.5K coldbox, an 45 g/s screw compressor, a 3800 liter liquid helium storage dewar, a 170 m{sup 3} warm gas storage tank, and a 40,000 liter vertical low pressure liquid nitrogen storage dewar. An existing wet expander obtained from another facility has been added to increase the plant capacity. In order to deliver the required 3 to 4 bar helium to the cryomodules while using up stored liquid capacity at low pressure, a new subcooler will be installed to function as the capacity transfer device. A 2K to 4K recovery heat exchanger is also implemented for each cryomodule to recover refrigeration below 4K, thus maximizing 2K cooling capacity with the given sub-atmospheric pump. No 4K-300K refrigeration recovery is implemented at this time of the returning sub-atmospheric cold vapor, hence the 2K load appears as a liquefaction1 load on the cryogenic plant. A separate LN2 cooling loop supplies liquid nitrogen to the superconducting gun's cathode tip.

  8. 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

  9. Using Composite Materials in a Cryogenic Pump

    NASA Technical Reports Server (NTRS)

    Batton, William D.; Dillard, James E.; Rottmund, Matthew E.; Tupper, Michael L.; Mallick, Kaushik; Francis, William H.

    2008-01-01

    Several modifications have been made to the design and operation of an extended-shaft cryogenic pump to increase the efficiency of pumping. In general, the efficiency of pumping a cryogenic fluid is limited by thermal losses which is itself caused by pump inefficiency and leakage of heat through the pump structure. A typical cryogenic pump includes a drive shaft and two main concentric static components (an outer pressure containment tube and an intermediate static support tube) made from stainless steel. The modifications made include replacement of the stainless-steel drive shaft and the concentric static stainless-steel components with components made of a glass/epoxy composite. The leakage of heat is thus reduced because the thermal conductivity of the composite is an order of magnitude below that of stainless steel. Taking advantage of the margin afforded by the decrease in thermal conductivity, the drive shaft could be shortened to increase its effective stiffness, thereby increasing the rotordynamic critical speeds, thereby further making it possible to operate the pump at a higher speed to increase pumping efficiency. During the modification effort, an analysis revealed that substitution of the shorter glass/epoxy shaft for the longer stainless-steel shaft was not, by itself, sufficient to satisfy the rotordynamic requirements at the desired increased speed. Hence, it became necessary to increase the stiffness of the composite shaft. This stiffening was accomplished by means of a carbon-fiber-composite overwrap along most of the length of the shaft. Concomitantly with the modifications described thus far, it was necessary to provide for joining the composite-material components with metallic components required by different aspects of the pump design. An adhesive material formulated specially to bond the composite and metal components was chosen as a means to satisfy these requirements.

  10. Isolation and Cryogenic Preservation of Monocytes from Plateletpheresis Cellular Residues.

    DTIC Science & Technology

    1983-01-11

    ISOLATION AND CRYOGENIC PRESERVATION OF I MONOCYTES FROM PLATELETPHERESIS CELLULAR RESIDUES Prepared for publication in TRANSFUSION Center for Blood...and Subtitle) S. TYPE OF REPORT 4 PERIOD COVERED Isolation and cryogenic preservation of mono- Technical Annual ytes from plateletpheresis cellular...If necoaamy mnd identify by block number) Monocytes, isolation, cryopreservation Plateletpheresis residues Counterflow centrifugation 20. ABSTRACT

  11. Cryogenic seal concept for static and dynamic conditions

    NASA Technical Reports Server (NTRS)

    De Gaetano, E. A.

    1968-01-01

    Seal rings reduce cryogenic pump seal leakage under static and dynamic conditions. The rings are fitted into annular diaphragms, which are affected by cryogenic pressure and temperature, to move against a mating ring, to increase seal-bearing loads under static conditions.

  12. 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.

  13. Cryogenic line insulation made from prefabricated polyurethane shells

    NASA Technical Reports Server (NTRS)

    Lerma, G.

    1975-01-01

    Prefabricated polyurethane foam insulation is inexpensive and easily installed on cryogenic lines. Insulation sections are semicircular half shells. Pair of half shells is placed to surround cryogenic line. Cylindrically-shaped knit sock is pulled over insulation then covered with polyurethane resin to seal system.

  14. Thermography to Inspect Insulation of Large Cryogenic Tanks

    NASA Technical Reports Server (NTRS)

    Arens, Ellen; Youngquist, Robert

    2011-01-01

    Thermography has been used in the past to monitor active, large, cryogenic storage tanks. This approach proposes to use thermography to monitor new or refurbished tanks, prior to filling with cryogenic liquid, to look for insulation voids. Thermography may provide significant cost and schedule savings if voids can be detected early before a tank is returned to service.

  15. Unlined Reuseable Filament Wound Composite Cryogenic Tank Testing

    NASA Technical Reports Server (NTRS)

    Murphy, A. W.; Lake, R. E.; Wilkerson, C.

    1999-01-01

    An unlined reusable filament wound composite cryogenic tank was tested at the Marshall Space Flight Center using LH2 cryogen and pressurization to 320 psig. The tank was fabricated by Phillips Laboratory and Wilson Composite Group, Inc., using an EnTec five-axis filament winder and sand mandrels. The material used was IM7/977-2 (graphite/epoxy).

  16. 49 CFR 173.319 - Cryogenic liquids in tank cars.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.319 Cryogenic liquids in tank...). (2) Ethylene, and hydrogen (minimum 95 percent parahydrogen), cryogenic liquids must be loaded and... Maximum start-to-discharge pressure (psig) Maximum permitted filling density (percent by weight)...

  17. 49 CFR 173.319 - Cryogenic liquids in tank cars.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.319 Cryogenic liquids in tank...). (2) Ethylene, and hydrogen (minimum 95 percent parahydrogen), cryogenic liquids must be loaded and... Maximum start-to-discharge pressure (psig) Maximum permitted filling density (percent by weight)...

  18. 49 CFR 173.319 - Cryogenic liquids in tank cars.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.319 Cryogenic liquids in tank...). (2) Ethylene, and hydrogen (minimum 95 percent parahydrogen), cryogenic liquids must be loaded and... Maximum start-to-discharge pressure (psig) Maximum permitted filling density (percent by weight)...

  19. Novel design of an all-cryogenic RF pound circuit

    NASA Technical Reports Server (NTRS)

    Basu, Ronni; Wang, Rabi T.; Dick, G. John

    2005-01-01

    We report on the design, construction and test of a new all-cryogenic RF Pound circuit used to stabilize a 100 MHz VCXO. Here, all active and passive RF components used to accomplish the phase modulation and detect a PM to AM conversion have been installed into the cryogenic environment.

  20. Contracting/expanding self-sealing cryogenic tube seals

    NASA Technical Reports Server (NTRS)

    Jia, Lin X. (Inventor)

    1997-01-01

    Contracting/expanding self-sealing cryogenic tube seals are disclosed which use the different properties of thermal contraction and expansion of selected dissimilar materials in accord with certain design criteria to yield self-tightening seals via sloped-surface sealing. The seals of the subject invention are reusable, simple to assemble, and adaptable to a wide variety of cryogenic applications.

  1. Cryogenic propulsion for the Titan Orbiter Polar Surveyor (TOPS) mission

    NASA Astrophysics Data System (ADS)

    Mustafi, S.; DeLee, C.; Francis, J.; Li, X.; McGuinness, D.; Nixon, C. A.; Purves, L.; Willis, W.; Riall, S.; Devine, M.; Hedayat, A.

    2016-03-01

    Liquid hydrogen (LH2) and liquid oxygen (LO2) cryogenic propellants can dramatically enhance NASA's ability to explore the solar system due to 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 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. These new cryogenic storage technologies were implemented in a design study for the Titan Orbiter Polar Surveyor (TOPS) mission, with LH2 and LO2 as propellants, and the resulting spacecraft design was able to achieve a 43% launch mass reduction over a TOPS mission, that utilized a traditional 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 that requires the cryogenics propellants to be stored for 8.5 years.

  2. Increasing the Cryogenic Toughness of Steels

    NASA Technical Reports Server (NTRS)

    Rush, H. F.

    1986-01-01

    Grain-refining heat treatments increase toughness without substantial strength loss. Five alloys selected for study, all at or near technological limit. Results showed clearly grain sizes of these alloys refined by such heat treatments and grain refinement results in large improvement in toughness without substantial loss in strength. Best improvements seen in HP-9-4-20 Steel, at low-strength end of technological limit, and in Maraging 200, at high-strength end. These alloys, in grain refined condition, considered for model applications in high-Reynolds-number cryogenic wind tunnels.

  3. Cryogenic 3D printing for tissue engineering.

    PubMed

    Adamkiewicz, Michal; Rubinsky, Boris

    2015-12-01

    We describe a new cryogenic 3D printing technology for freezing hydrogels, with a potential impact to tissue engineering. We show that complex frozen hydrogel structures can be generated when the 3D object is printed immersed in a liquid coolant (liquid nitrogen), whose upper surface is maintained at the same level as the highest deposited layer of the object. This novel approach ensures that the process of freezing is controlled precisely, and that already printed frozen layers remain at a constant temperature. We describe the device and present results which illustrate the potential of the new technology.

  4. Properties of a nanodielectric cryogenic resin

    SciTech Connect

    Polyzos, Georgios; Tuncer, Enis; Sauers, Isidor; More, Karren Leslie

    2010-01-01

    Physical properties of a nanodielectric composed of in situ synthesized titanium dioxide (TiO{sub 2}) nanoparticles ({le} 5 nm in diameter) and a cryogenic resin are reported. The dielectric losses were reduced by a factor of 2 in the nanocomposite, indicating that the presence of small TiO{sub 2} nanoparticles restricted the mobility of the polymer chains. Dielectric breakdown data of the nanodielectric was distributed over a narrower range than that of the unfilled resin. The nanodielectric had 1.56 times higher 1% breakdown probability than the resin, yielding 0.64 times thinner insulation thickness for the same voltage level, which is beneficial in high voltage engineering.

  5. Low heat-leak cryogenic envelope

    DOEpatents

    DeHaan, James R.

    1976-10-19

    A plurality of cryogenic envelope sections are joined together to form a power transmission line. Each of the sections is comprised of inner and outer tubes having multilayer metalized plastic spirally wrapped within a vacuum chamber formed between the inner and outer tubes. A refrigeration tube traverses the vacuum chamber, but exits one section and enters another through thermal standoffs for reducing heat-leak from the outer tube to the refrigeration tube. The refrigeration tube passes through a spirally wrapped shield within each section's vacuum chamber in a manner so that the refrigeration tube is in close thermal contact with the shield, but is nevertheless slideable with respect thereto.

  6. Pressure transducer and system for cryogenic environments

    NASA Technical Reports Server (NTRS)

    Chapman, John J. (Inventor)

    1992-01-01

    A silicon pressure die is bonded to a borosilicate substrate above the pneumatic port. A Wheatstone bridge circuit is formed on the silicon pressure die and has bridge elements of silicon doped with boron to a deposit density level of approximately 1 x 10(exp 19)-10(exp 21) boron/cc. A current source is provided to excite the Wheatstone bridge circuit. In addition, a temperature sensor is provided to provide temperature readings. An array may be formed of the resulting pressure transducers. This unique solution of materials permits operation of a pressure transducer in cryogenic environments.

  7. Stability limit of the cryogenic hydrogen maser

    SciTech Connect

    Maan, A.C.; Stoof, H.T.C.; Verhaar, B.J. ); Mandel, P. )

    1990-05-28

    It is pointed out that the usual oscillation condition of the H maser is only a necessary condition for steady operation. Reducing the coupled field-matter dynamics to the complex Lorenz equations we derive a second requirement which together with the first forms a set of necessary and sufficient conditions for the steady operation to be stable. The instability of the steady state predicted by the equations should be easily accessible experimentally for the cryogenic H maser. It will be characterized by a pulsed output power which, depending on the detuning, is either periodic or chaotic.

  8. Linear beam raster for cryogenic targets

    SciTech Connect

    Yan, C; Sinkine, N; Wojcik, R

    2005-02-21

    Based on the H-bridge switch technique a linear beam raster system was developed in 2002. The system generates a rectangular raster pattern with highly uniform ({approx}95%) raster density distribution on cryogenic targets. The two raster frequencies are 24.96 and 25.08 kHz. The turning time at the vertex is 200 ns and the scan linearity is 98%. The beam-heating effect on the target is effectively eliminated. The new raster system allows the use of higher beam current toward 200 muA in many of the experimental proposals at end station Hall A and Hall C of the Jefferson lab.

  9. Physicists make a difference in space cryogenics

    NASA Technical Reports Server (NTRS)

    Petrac, D.

    1990-01-01

    An evaluation is made of space cryogenics technology development challenges in whose treatment the unique abilities of physicists have been notably valuable. In addition to such broad concerns as the quantum properties of superfluid He, the basic laws of thermodynamics and entropy, and quantization of such fields as those of phonons and magnons, productive efforts have been made by physicists in the basic principles of SQUIDs, magnetic shielding due to the Meissner effect in superconductors, adiabatic demagnetization, and dilution cooling of He-3 and He-4. These contributions will be of fundamental importance to the IR Telescope for Space and Advanced X-ray Astronomical Facility, which are currently under development.

  10. Storage tank for cryogenic liquefied gas

    SciTech Connect

    Guilhem, J. R.

    1985-02-12

    The invention is related to a tank designed to contain a cryogenic liquefied gas and formed in addition to the main tank by two other tight walls. In the upper part of this tank an aperture duct connects the ceiling of the tank to the exterior of the tank, a holder supporting a device sensing in various areas wall temperatures of the tank, can be fitted into this aperture duct, a remote temperature sensor is actually hold by this support and is introduced into the tank. The invention finds an application as a means to easily localize leaking failures of the intermediate wall.

  11. 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.

  12. 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

  13. 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.

  14. Infrared detectors and test technology of cryogenic camera

    NASA Astrophysics Data System (ADS)

    Yang, Xiaole; Liu, Xingxin; Xing, Mailing; Ling, Long

    2016-10-01

    Cryogenic camera which is widely used in deep space detection cools down optical system and support structure by cryogenic refrigeration technology, thereby improving the sensitivity. Discussing the characteristics and design points of infrared detector combined with camera's characteristics. At the same time, cryogenic background test systems of chip and detector assembly are established. Chip test system is based on variable cryogenic and multilayer Dewar, and assembly test system is based on target and background simulator in the thermal vacuum environment. The core of test is to establish cryogenic background. Non-uniformity, ratio of dead pixels and noise of test result are given finally. The establishment of test system supports for the design and calculation of infrared systems.

  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 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.

  17. Introduction to Quantum Sensors in Cryogenic Particle Detection

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Hamb; Kim, Sun Kee

    Cryogenic detectors have been important tools in many aspects of science because their sensitivities can provide more than extreme limits of conventional semiconductor based detectors. The sensor developments in cryogenic particle detection are based on the precise measurement of noble properties of condensed matter in low temperatures. The major measurement technologies originate from quantum measurements, phase transitions and superconducting electronics. Although the early developments of cryogenic detectors were initiated by applications to elementary particle physics, they have been adopted in biology, forensics, and security as well as astronomy and nuclear science. Various types of cryogenic detectors cover a wide energy range from THz radiations to hundreds MeV particles. We review the recent development of sensor technologies in cryogenic particle detection. The measurement principles are covered together with applications to elementary particle physics and THz measurement.

  18. Minimally Invasive Ear Reshaping With a 1450-nm Diode Laser Using Cryogen Spray Cooling in New Zealand White Rabbits

    PubMed Central

    Holden, Paul K.; Chlebicki, Cara; Wong, Brian J. F.

    2014-01-01

    Background Otoplasty is the current standard of care for treating prominent ears, a psychologically and sometimes functionally disabling disorder. The technically demanding procedure carries many risks such as poor aesthetic outcome, need for revision surgery, and need for general anesthesia. This study investigates the use of laser irradiation combined with cryogen skin cooling and stenting to reshape cartilage in the ears of New Zealand white rabbits. Methods In this prospective, randomized, internally controlled animal study, the right ears of 9 rabbits were mechanically deformed with a jig and then irradiated with a 1450-nm diode laser combined with cryogen skin cooling (14 J/pulse with cryogen spray for 33 milliseconds per cycle and a 6-mm spot size). The left ear served as the control. The ears were splinted for 1, 3, or 4 weeks. The rabbits were then given a lethal dose of intravenous pentobarbital, and the splints were removed and ears examined and photographed. Light and confocal microscopy were performed on the specimens. Results Shape change was observed in all 9 treated rabbit ears, while none of the control ears (stenting alone) showed significant change. Qualitatively, reshaped ears were stiffer after 4 weeks of splinting than after 1 or 3 weeks. None of the rabbits showed evidence of skin injury nor did they show signs of postprocedural pain. Findings from histologic analysis in the treated areas showed evidence of an expanded chondrocyte population in the region of laser irradiation, along with some perichondrial thickening and some fibrosis of the deep dermis. Confocal microscopy revealed minimal cellular death at 1 week and none thereafter. Conclusions Cartilage reshaping using laser energy can be performed safely transcutaneously using cryogen spray cooling in rabbits. This animal model has similarity to human ears with regard to skin and cartilage thickness and is a stepping stone toward developing minimally invasive laser auricle reshaping in

  19. 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.

  20. Nonbright spot AVO: Two examples

    SciTech Connect

    Ross, C.P.; Kinman, D.L.

    1994-12-31

    Utilization of amplitude-versus-offset (AVO) attribute sections such as the product of the normal incidence trace and gradient trace have been used extensively in bright spot (Class 3) AVO analysis and interpretation. However, while these sections have often worked well with Class 3 responses they are not reliable indicators of non-bright spot (Class 2) seismic anomalies. Analyzing Class 2 seismic data with AVO products will: (1) not detect the gas-charged reservoir because of near-zero acoustic impedance contrast between the sands and encasing shales, or (2) yield an incorrect (negative) AVO product if the normal incidence and gradient values are opposite in sign. Class 2 offset responses are divided into two sub-categories: those with phase reversals (Class 2p) and those without phase reversals (Class 2). An AVO procedure for these types of Class 2 anomalies is presented through two examples. The technique better exploits the nature of the prestack response, yielding a more definitive AVO attribute section, and the technique is adaptive to both Class 2 and Class 2p responses. When compared to a conventionally processed relative amplitude seismic section with characteristically low amplitude responses for near-zero acoustic impedance sands, this procedure clearly denotes the presence of gas-charged pore fluids within the reservoir.

  1. Still from Red Spot Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This image is one of seven from the narrow-angle camera on NASA's Cassini spacecraft assembled as a brief movie of cloud movements on Jupiter. It was taken with a blue filter. The smallest features visible are about 500 kilometers (about 300 miles) across.

    Small bright clouds appear suddenly to the west of the Great Red Spot. Based on data from NASA's Galileo spacecraft, scientists suspect that these small white features are lightning storms, where falling raindrops create an electrical charge. The lightning storms eventually merge with the Red Spot and surrounding jets, and may be the main energy source for these large-scale features. Imaging observations of the darkside of the planet in the weeks following Cassini's closest approach to Jupiter on Dec. 30, 2000 will search for lightning storms like these.

    This image was re-projected by cylindrical-map projection of an image taken in the first week of October 2000. It shows an area from 50 degrees north of Jupiter's equator to 50 degrees south, extending 100 degrees east west, about one quarter of Jupiter's circumference.

    Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  2. Spot and Runway Departure Advisor

    NASA Technical Reports Server (NTRS)

    Jung, Yoon Chul

    2013-01-01

    The Spot and Runway Departure Advisor (SARDA) is a research prototype of a decision support tool for ATC tower controllers to assist in manging and controlling traffic on the surface of an airport. SARDA employs a scheduler to generate an optimal runway schedule and gate push-back - spot release sequence and schedule that improves efficiency of surface operations. The advisories for ATC tower controllers are displayed on an Electronic Flight Strip (EFS) system. The human-in-the-loop simulation of the SARDA tool was conducted for east operations of Dallas-Ft. Worth International Airport (DFW) to evaluate performance of the SARDA tool and human factors, such as situational awareness and workload. The results indicates noticeable taxi delay reduction and fuel savings by using the SARDA tool. Reduction in controller workload were also observed throughout the scenario runs. The future plan includes modeling and simulation of the ramp operations of the Charlotte International Airport, and develop a decision support tool for the ramp controllers.

  3. Instructor Debrief Training in SPOT

    NASA Technical Reports Server (NTRS)

    Martin, Lynne; Orasanu, Judith; Villeda, Eric; Conners, Mary M. (Technical Monitor)

    2002-01-01

    One way to enhance the effectiveness of Special Purpose Operational Training' (SPOT) debriefing sessions may be for instructors to make explicit connections between the Crew Resource Management (CRM) concepts a carrier advocates and the behaviors displayed by the crew in question. A tool listing key behaviors from the scenario was devised, accompanied by an instructors' training session in which links were made between the behaviors and the underlying CRM processes they reflect. The aim of the tool is to assist instructors to focus the debriefing on the key SPOT/ CRM issues, in this case on planning. A second tool suggested ways to facilitate the discussion. Fourteen instructors at a major U.S. carrier took part in the training session and used the toolkit in their subsequent debriefs. Pre- and post-training debriefing samples from each instructor were compared to assess whether there were any changes in instructors' approaches to discussions in terms of the topics they covered and how they raised the points.

  4. Solar 'hot spots' are still hot

    NASA Technical Reports Server (NTRS)

    Bai, Taeil

    1990-01-01

    Longitude distributions of solar flares are not random but show evidence for active zones (or hot spots) where flares are concentrated. According to a previous study, two hot spots in the northern hemisphere, which rotate with a synodic period of about 26.72 days, produced the majority of major flares, during solar cycles 20 and 21. The more prominent of these two hot spots is found to be still active during the rising part of cycle 22, producing the majority of northern hemisphere major flares. The synodic rotation period of this hot spot is 26.727 + or - 0.007 days. There is also evidence for hot spots in the southern hemisphere. Two hot spots separated by 180 deg are found to rotate with a period of 29.407 days, with one of them having persisted in the same locations during cycles 19-22 and the other, during cycles 20-22.

  5. Spotted bass Micropterus punctulatus (Rafinesque 1819)

    USGS Publications Warehouse

    Churchill, Timothy N.; Bettoli, Phillip William

    2015-01-01

    Three subspecies of Spotted Bass Micropterus punctulatus were historically recognized: the smaller Northern Spotted Bass M. p. punctulatus, the larger, longer-lived Alabama Spotted Bass M. p. henshalli, and the now invalidated Wichita Spotted Bass M. p. wichitae (Bailey and Hubbs 1940; Cofer 1995; Warren 2009; Rider and Maceina 2015, this volume). The subspecific status has been examined over the past decade as advanced genetic analyses have been developed (e.g., Kassler et al. 2002; Baker et al. 2008; Tringali et al. 2015, this volume). The American Fisheries Society has recently changed the designation of the Alabama Spotted Bass to a separate species, Alabama Bass M. henshalli (Page et al. 2013). The remainder of this paper will discuss the biology and conservation of only Spotted Bass. Both species have been observed to hybridize with other Micropterus spp. (Koppelman 1994; Pierce and Van Den Avyle 1997; Barwick et al. 2006).

  6. Integrating sustainable hunting in biodiversity protection in Central Africa: hot spots, weak spots, and strong spots.

    PubMed

    Fa, John E; Olivero, Jesús; Farfán, Miguel Ángel; Márquez, Ana Luz; Vargas, Juan Mario; Real, Raimundo; Nasi, Robert

    2014-01-01

    Wild animals are a primary source of protein (bushmeat) for people living in or near tropical forests. Ideally, the effect of bushmeat harvests should be monitored closely by making regular estimates of offtake rate and size of stock available for exploitation. However, in practice, this is possible in very few situations because it requires both of these aspects to be readily measurable, and even in the best case, entails very considerable time and effort. As alternative, in this study, we use high-resolution, environmental favorability models for terrestrial mammals (N = 165) in Central Africa to map areas of high species richness (hot spots) and hunting susceptibility. Favorability models distinguish localities with environmental conditions that favor the species' existence from those with detrimental characteristics for its presence. We develop an index for assessing Potential Hunting Sustainability (PHS) of each species based on their ecological characteristics (population density, habitat breadth, rarity and vulnerability), weighted according to restrictive and permissive assumptions of how species' characteristics are combined. Species are classified into five main hunting sustainability classes using fuzzy logic. Using the accumulated favorability values of all species, and their PHS values, we finally identify weak spots, defined as high diversity regions of especial hunting vulnerability for wildlife, as well as strong spots, defined as high diversity areas of high hunting sustainability potential. Our study uses relatively simple models that employ easily obtainable data of a species' ecological characteristics to assess the impacts of hunting in tropical regions. It provides information for management by charting the geography of where species are more or less likely to be at risk of extinction from hunting.

  7. 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.

  8. 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.

  9. 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.

  10. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Astrophysics Data System (ADS)

    Henderson, S. W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Calabrese, E.; Choi, S. K.; Coughlin, K. P.; Crowley, K. T.; Datta, R.; Devlin, M. J.; Duff, S. M.; Dunkley, J.; Dünner, R.; van Engelen, A.; Gallardo, P. A.; Grace, E.; Hasselfield, M.; Hills, F.; Hilton, G. C.; Hincks, A. D.; Hloẑek, R.; Ho, S. P.; Hubmayr, J.; Huffenberger, K.; Hughes, J. P.; Irwin, K. D.; Koopman, B. J.; Kosowsky, A. B.; Li, D.; McMahon, J.; Munson, C.; Nati, F.; Newburgh, L.; Niemack, M. D.; Niraula, P.; Page, L. A.; Pappas, C. G.; Salatino, M.; Schillaci, A.; Schmitt, B. L.; Sehgal, N.; Sherwin, B. D.; Sievers, J. L.; Simon, S. M.; Spergel, D. N.; Staggs, S. T.; Stevens, J. R.; Thornton, R.; Van Lanen, J.; Vavagiakis, E. M.; Ward, J. T.; Wollack, E. J.

    2016-08-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies—imaged in intensity and polarization at few arcminute-scale resolution—will enable precision cosmological constraints and also a wide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the Advanced ACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the Advanced ACTPol cryogenic detector arrays.

  11. Buffeting tests in a cryogenic windtunnel

    NASA Technical Reports Server (NTRS)

    Mabey, D. G.; Boyden, R. P.; Johnson, W. G.

    1995-01-01

    Measurements of wing buffeting, using root strain gages, were made in the NASA Langley 0.3 m cryogenic wind tunnel to refine techniques which will be used in larger cryogenic facilities such as the United States National Transonic Facility (NTF) and the European Transonic Wind Tunnel (ETW). The questions addressed included the relative importance variations in frequency parameter and Reynolds number, the choice of model material (considering both stiffness and damping) and the effects of static aeroelastic distortion. The main series of tests was made on three half models of slender 65 deg delta wings with a sharp leading edge. The three delta wings had the same planform but widely differing bending stiffnesses and frequencies (obtained by varying both the material and the thickness of the wings). It was known that the steady flow on this configuration would be insensitive to variations in Reynolds number. On this wing at vortex breakdown the spectrum of the unsteady excitation is unusual, having a sharp peak at particular frequency parameter. Additional tests were made on one unswept half-wing of aspect ratio 1.5 with an NPL 9510 aerofoil section, known to be sensitive to variations in Reynolds number at transonic speeds. The test Mach numbers were M = 0.21 and 0.35 for the delta wings and to M = 0.30 for the unswept wing. On this wing the unsteady excitation spectrum is fairly flat (as on most wings). Hence correct representation of the frequency parameter is not particularly important.

  12. Advanced ACTPol Cryogenic Detector Arrays and Readout

    NASA Technical Reports Server (NTRS)

    Henderson, S.W.; Allison, R.; Austermann, J.; Baildon, T.; Battaglia, N.; Beall, J. A.; Becker, D.; De Bernardis, F.; Bond, J. R.; Wollack, E. J.

    2016-01-01

    Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope, adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background anisotropies-imaged in intensity and polarization at few arcminute-scale resolution-will enable precision cosmological constraints and also awide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the AdvancedACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the AdvancedACTPol cryogenic detector arrays.

  13. Cryogenic Heat Engines Made Using Electrocaloric Capacitors

    NASA Astrophysics Data System (ADS)

    Franz, Justin; Ordonez, Carlos A.

    2001-10-01

    It is possible to operate a heat engine using a cold substance, such as liquid nitrogen, as a heat sink and the atmosphere as a heat source.(C. A. Ordonez, American Journal of Physics 64), (1996) 479-481. With sufficient work produced per unit mass of liquid nitrogen, such a cryogenic heat engine may be suitable for powering short range, non-polluting automobiles.(C. A. Ordonez, Energy Conversion and Management 41) (2000) 331-341. Using existing liquid nitrogen plants to produce liquid nitrogen at about 50% of Carnot efficiency, and using renewable energy to power the liquid nitrogen plants, the cost to use liquid nitrogen to power an automobile per mile driven would be a few times the cost of using gasoline in the U.S. The increased ``fuel" cost may be acceptable for short range vehicles provided such vehicles have an acceptable price. We report on thermal-to-electrical energy conversion systems being studied for use as cryogenic heat engines. Specifically, capacitors made using paraelectric materials can provide energy conversion based on the electrocaloric effect. The electrocaloric effect is a change in electric field across a material that results from a change in temperature of the material.

  14. Thermal Design of a Collapsible Cryogenic Vessel

    NASA Technical Reports Server (NTRS)

    Hegab, Hisham E.

    2001-01-01

    Strategic planning for human exploration missions to Mars has conclusively identified in-situ resource utilization (ISRU) as an enabling technology. Most mission scenarios include an ISRU plant to produce propellants for ascent from Mars as well as the production of backup reserves of water, oxygen, and process gases. Current mission scenarios call for an ISRU plant to be deployed and then produce and store the required propellants and life support reserves before the arrival of the first human mission. Reliable cryogenic propellant liquefaction and storage technologies for extended period missions are especially critical. This report examines the cryogenic storage problem for liquid oxygen produced by an ISRU plant for a human mission scenario. The analysis examines various hardware configurations including insulation types, packaging techniques, and required cryocoolers to minimize the initial launch mass to low Earth orbit. Results of the analyses indicate that high vacuum insulation systems requiring vacuum pressures below one millitorr will be required to minimize the 'initial launch mass into low Earth orbit even though the temperature on the surface of Mars is much lower than Earth.

  15. Fielding the NIF Cryogenic Ignition Target

    SciTech Connect

    Malsbury, T; Haid, B; Gibson, C; Atkinson, D; Skulina, K; Klingmann, J; Atherton, J; Mapoles, E; Kozioziemski, B; Dzenitis, E

    2008-02-28

    The United States Department of Energy has embarked on a campaign to conduct credible fusion ignition experiments on the National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory in 2010. The target assembly specified for this campaign requires the formation of a deuterium/tritium (DT) fuel ice layer on the inside of a 2 millimeter diameter capsule positioned at the center of a 9 millimeter long by 5 millimeter diameter cylinder, called a hohlraum. The ice layer requires micrometer level accuracy and must be formed and maintained at temperatures below 19 K. At NIF shot time, the target must be positioned at the center of the NIF 10 meter diameter target chamber, aligned to the laser beam lines and held stable to less than 7 micrometers rms. We have completed the final design and are integrating the systems necessary to create, characterize and field the cryogenic target for ignition experiments. These designs, with emphasis on the challenges of fielding a precision cryogenic positioning system will be presented.

  16. 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.

  17. 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.

  18. 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.

  19. The cryogenic gas stopping cell of SHIPTRAP

    NASA Astrophysics Data System (ADS)

    Droese, C.; Eliseev, S.; Blaum, K.; Block, M.; Herfurth, F.; Laatiaoui, M.; Lautenschläger, F.; Minaya Ramirez, E.; Schweikhard, L.; Simon, V. V.; Thirolf, P. G.

    2014-11-01

    The overall efficiency of the Penning-trap mass spectrometer SHIPTRAP at GSI Darmstadt, employed for high-precision mass measurements of exotic nuclei in the mass region above fermium, is presently mostly limited by the stopping and extraction of fusion-evaporation products in the SHIPTRAP gas cell. To overcome this limitation a second-generation gas cell with increased stopping volume was designed. In addition, its operation at cryogenic temperatures leads to a higher gas density at a given pressure and an improved cleanliness of the helium buffer gas. Here, the results of experiments with a 219Rn recoil ion source are presented. An extraction efficiency of 74(3)% was obtained, a significant increase compared to the extraction efficiency of 30% of the present gas stopping cell operated at room temperature. The optimization of electric fields and other operating parameters at room as well as cryogenic temperatures is described in detail. Furthermore, the extraction time of 219Rn ions was determined for several operating parameters.

  20. 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.

  1. High efficiency, variable geometry, centrifugal cryogenic pump

    SciTech Connect

    Forsha, M.D.; Nichols, K.E.; Beale, C.A.

    1994-12-31

    A centrifugal cryogenic pump has been developed which has a basic design that is rugged and reliable with variable speed and variable geometry features that achieve high pump efficiency over a wide range of head-flow conditions. The pump uses a sealless design and rolling element bearings to achieve high reliability and the ruggedness to withstand liquid-vapor slugging. The pump can meet a wide range of variable head, off-design flow requirements and maintain design point efficiency by adjusting the pump speed. The pump also has features that allow the impeller and diffuser blade heights to be adjusted. The adjustable height blades were intended to enhance the pump efficiency when it is operating at constant head, off-design flow rates. For small pumps, the adjustable height blades are not recommended. For larger pumps, they could provide off-design efficiency improvements. This pump was developed for supercritical helium service, but the design is well suited to any cryogenic application where high efficiency is required over a wide range of head-flow conditions.

  2. Advances in cryogenic engineering. Volume 27 - Proceedings of the Cryogenic Engineering Conference, San Diego, CA, August 11-14, 1981

    NASA Technical Reports Server (NTRS)

    Fast, R. W. (Editor)

    1982-01-01

    Applications of superconductivity are considered, taking into account MHD and fusion, generators, transformers, transmission lines, magnets for physics, cryogenic techniques, electrtronics, and aspects of magnet stability. Advances related to heat transfer in He I are discussed along with subjects related to theat transfer in He II, refrigeration of superconducting systems, refrigeration and liquefaction, dilution and magnetic refrigerators, refrigerators for space applications, mass transfer and flow phenomena, and the properties of fluids. Developments related to cryogenic applications are also explored, giving attention to bulk storage and transfer of cryogenic fluids, liquefied natural gas operations, space science and technology, and cryopumping. Topics related to cryogenic instrumentation and controls include the production and use of high grade silicon diode temperature sensors, the choice of strain gages for use in a large superconducting alternator, microprocessor control of cryogenic pressure, and instrumentation, data acquisition and reduction for a large spaceborne helium dewar.

  3. Predictive process simulation of cryogenic implants for leading edge transistor design

    SciTech Connect

    Gossmann, Hans-Joachim; Zographos, Nikolas; Park, Hugh; Colombeau, Benjamin; Parrill, Thomas; Khasgiwale, Niranjan; Borges, Ricardo; Gull, Ronald; Erokhin, Yuri

    2012-11-06

    Two cryogenic implant TCAD-modules have been developed: (i) A continuum-based compact model targeted towards a TCAD production environment calibrated against an extensive data-set for all common dopants. Ion-specific calibration parameters related to damage generation and dynamic annealing were used and resulted in excellent fits to the calibration data-set. (ii) A Kinetic Monte Carlo (kMC) model including the full time dependence of ion-exposure that a particular spot on the wafer experiences, as well as the resulting temperature vs. time profile of this spot. It was calibrated by adjusting damage generation and dynamic annealing parameters. The kMC simulations clearly demonstrate the importance of the time-structure of the beam for the amorphization process: Assuming an average dose-rate does not capture all of the physics and may lead to incorrect conclusions. The model enables optimization of the amorphization process through tool parameters such as scan speed or beam height.

  4. Voyager 1 Red Spot Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie shows the portion of Jupiter around the Great Red Spot as it swirls through more than 60 Jupiter days. Notice the difference in speed and direction of the various zones of the atmosphere. The interaction of the atmospheric clouds and storm shows how dynamic the Jovian atmosphere is.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 66 images taken once every Jupiter rotation period (about 10 hours). This time-lapse movie uses images taken every time Jupiter longitude 68W passed under the spacecraft. These images were acquired in the Blue filter from Jan. 6 to Feb. 3 1979. The spacecraft flew from 58 million kilometers to 31 million kilometers from Jupiter during that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  5. Fatal Rocky Mountain spotted fever.

    PubMed

    Hattwick, M A; Retailliau, H; O'Brien, R J; Slutzker, M; Fontaine, R E; Hanson, B

    1978-09-29

    Forty-four fatal cases of Rocky Mountain spotted fever (RMSF) occurring in 1974 were compared with 50 nonfatal cases of similar age, sex, date of onset, and place of occurrence. Diagnosis and initiation of treatment in fatal cases were substantially delayed compared with nonfatal cases. Several reasons for this delay were identified: (1) the rash appeared later in the course of illness in the fatal cases, often not until the patient was terminal, (2) a history of tick bite was less often obtained during life or obtained late in the clinical course in fatal cases, and (3) initial nonspecific symptoms or unexpected symptoms led to an initial diagnosis of more common diseases. Only two fatal cases were treated with either tetracycline or chloramphenicol before the sixth day of illness. Presumptive diagnosis of RMSF and initiation of tetracycline therapy before onset of rash may be necessary to reduce mortality.

  6. SU-E-T-510: Interplay Between Spots Sizes, Spot / Line Spacing and Motion in Spot Scanning Proton Therapy

    SciTech Connect

    Lee, TK

    2015-06-15

    Purpose In proton beam configuration for spot scanning proton therapy (SSPT), one can define the spacing between spots and lines of scanning as a ratio of given spot size. If the spacing increases, the number of spots decreases which can potentially decrease scan time, and so can whole treatment time, and vice versa. However, if the spacing is too large, the uniformity of scanned field decreases. Also, the field uniformity can be affected by motion during SSPT beam delivery. In the present study, the interplay between spot/ line spacing and motion is investigated. Methods We used four Gaussian-shape spot sizes with 0.5cm, 1.0cm, 1.5cm, and 2.0cm FWHM, three spot/line spacing that creates uniform field profile which are 1/3*FWHM, σ/3*FWHM and 2/3*FWHM, and three random motion amplitudes within, +/−0.3mm, +/−0.5mm, and +/−1.0mm. We planned with 2Gy uniform single layer of 10×10cm2 and 20×20cm2 fields. Then, mean dose within 80% area of given field size, contrubuting MU per each spot assuming 1cGy/MU calibration for all spot sizes, number of spots and uniformity were calculated. Results The plans with spot/line spacing equal to or smaller than 2/3*FWHM without motion create ∼100% uniformity. However, it was found that the uniformity decreases with increased spacing, and it is more pronounced with smaller spot sizes, but is not affected by scanned field sizes. Conclusion It was found that the motion during proton beam delivery can alter the dose uniformity and the amount of alteration changes with spot size which changes with energy and spot/line spacing. Currently, robust evaluation in TPS (e.g. Eclipse system) performs range uncertainty evaluation using isocenter shift and CT calibration error. Based on presented study, it is recommended to add interplay effect evaluation to robust evaluation process. For future study, the additional interplay between the energy layers and motion is expected to present volumetric effect.

  7. 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

  8. Ambystoma maculatum (spotted salamander). Reproduction

    USGS Publications Warehouse

    Glorioso, Brad M.; Waddle, Hardin; Hefner, Jeromi

    2012-01-01

    The Spotted Salamander is a wide-ranging salamander of the eastern United States that typically breeds in winter or early spring in ephemeral pools in lowland forests. Ambystoma maculatum is known to deposit 2-4 egg masses per year, each containing 1-250 eggs. As part of ongoing research into the ecology and reproductive biology of Spotted Salamanders in the Kisatchie District of Kisatchie National Forest in Natchitoches Parish, Louisiana, USA, we have been counting the number of embryos per egg mass. We captured seven female A. maculatum in a small pool, six of which were still gravid. We took standard measurements, including SVL, and then implanted a Passive Integrated Transponder (PIT tag) into each adult female as was the protocol. About an hour after processing these animals we marked new A. maculatum egg masses found in the same small pool using PVC pin flags pushed carefully through the outer jelly. We did not have enough time to process them that evening, and it was not until a few days later that we photographed those masses. We discovered that one of the masses contained a PIT tag in the outer jelly that corresponded to one of the six gravid females that were marked that same evening. To our knowledge, this is the first report of PIT tags being the means, albeit coincidentally, by which a particular egg mass of Ambystoma maculatum has been assigned to a particular female. For our purposes, losing the PIT tag from the adult female is counter to the goals of our study of this population, and we will no longer be implanting PIT tags into gravid females.

  9. 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.

  10. 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

  11. Thermal Stabilization in a High Vacuum Cryogenic Optical System

    NASA Astrophysics Data System (ADS)

    Wallace, Rosa; Cripe, Jonathan; Corbitt, Thomas

    2016-03-01

    The existing technology for gravitational wave detection is limited in part by quantum noise. In our tabletop experiments, we are attempting to lower the noise floor to the quantum limit through the use of a seismically isolated cryogenic high vacuum environment, with the intention of exploring different methods to reduce quantum noise. In the development phase of this environment, we have implemented a customized strategy of ultraviolet irradiation combined with cryogenically cooled radiation shielding to reduce the impact of water vapor and blackbody radiation on the thermal stability of the cryogenic micro-components. Supported by National Science Foundation REU Site #1262890 and CAREER Award #1150531.

  12. Lightweight cryogenic-compatible pressure vessels for vehicular fuel storage

    DOEpatents

    Aceves, Salvador; Berry, Gene; Weisberg, Andrew H.

    2004-03-23

    A lightweight, cryogenic-compatible pressure vessel for flexibly storing cryogenic liquid fuels or compressed gas fuels at cryogenic or ambient temperatures. The pressure vessel has an inner pressure container enclosing a fuel storage volume, an outer container surrounding the inner pressure container to form an evacuated space therebetween, and a thermal insulator surrounding the inner pressure container in the evacuated space to inhibit heat transfer. Additionally, vacuum loss from fuel permeation is substantially inhibited in the evacuated space by, for example, lining the container liner with a layer of fuel-impermeable material, capturing the permeated fuel in the evacuated space, or purging the permeated fuel from the evacuated space.

  13. Thermohydrodynamic analysis of cryogenic liquid turbulent flow fluid film bearings

    NASA Technical Reports Server (NTRS)

    Andres, Luis San

    1993-01-01

    A thermohydrodynamic analysis is presented and a computer code developed for prediction of the static and dynamic force response of hydrostatic journal bearings (HJB's), annular seals or damper bearing seals, and fixed arc pad bearings for cryogenic liquid applications. The study includes the most important flow characteristics found in cryogenic fluid film bearings such as flow turbulence, fluid inertia, liquid compressibility and thermal effects. The analysis and computational model devised allow the determination of the flow field in cryogenic fluid film bearings along with the dynamic force coefficients for rotor-bearing stability analysis.

  14. Effect of Nuclear Radiation on Materials at Cryogenic Temperatures

    NASA Technical Reports Server (NTRS)

    Schwanbeck, C. A.

    1965-01-01

    The tensile properties for 33 polycrystalline structural materials including aluminum, titanium, nickel and iron alloys were obtained at -256.5 C (30 deg R) after irradiation exposure at this temperature to 10(exp 17) nvt (E greater than 0.5 Mev), at -256.5 C without previous irradiation, and at approximately 27 C (540 deg R) without previous irradiation. The data were evaluated statistically to permit identification of cryogenic effects and nuclear-cryogenic effects. A number of conclusions were drawn regarding suitability of certain of the materials for use in nuclear-cryogenic applications and regarding the need for further investigation.

  15. 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.

  16. Threaded insert for compact cryogenic-capable pressure vessels

    DOEpatents

    Espinosa-Loza, Francisco; Ross, Timothy O.; Switzer, Vernon A.; Aceves, Salvador M.; Killingsworth, Nicholas J.; Ledesma-Orozco, Elias

    2015-06-16

    An insert for a cryogenic capable pressure vessel for storage of hydrogen or other cryogenic gases at high pressure. The insert provides the interface between a tank and internal and external components of the tank system. The insert can be used with tanks with any or all combinations of cryogenic, high pressure, and highly diffusive fluids. The insert can be threaded into the neck of a tank with an inner liner. The threads withstand the majority of the stress when the fluid inside the tank that is under pressure.

  17. A Pump for Liquid Cryogen with HTS Electrical Drive

    NASA Astrophysics Data System (ADS)

    Kovalev, L. K.; Ilushin, K. V.; Penkin, V. T.; Kovalev, K. L.; Larionoff, A. E.; Poltavets, V. N.; Koneev, S. M.-A.; Larionoff, S. A.; Modestov, K. A.; Akimov, I. I.; Verzhbitsky, L. G.; Trifonov, Ye. Ye.; Logviniouk, V. P.; Dew-Hughes, D.

    2004-06-01

    This work describes the research and development of a cryogenic pump that is intended for the fuel supply of aircraft engines using advanced low temperature fuel. The basic design is that of 4-pole reluctance motor. The rotor is constructed from soft iron and BSCCO/Ag laminated material; the latter developed by the All-Russian Scientific Research Institute of Inorganic Materials. The motor was integrated with a centrifugal cryogenic pump for the cryogenic fuel supply system, developed by the TUPOLEV Company. The results of theoretical modelling and experimental investigations are presented.

  18. Cryogenic Fluid Management Technology Development for Nuclear Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    Taylor, B. D.; Caffrey, J.; Hedayat, A.; Stephens, J.; Polsgrove, R.

    2015-01-01

    Cryogenic fluid management technology is critical to the success of future nuclear thermal propulsion powered vehicles and long duration missions. This paper discusses current capabilities in key technologies and their development path. The thermal environment, complicated from the radiation escaping a reactor of a nuclear thermal propulsion system, is examined and analysis presented. The technology development path required for maintaining cryogenic propellants in this environment is reviewed. This paper is intended to encourage and bring attention to the cryogenic fluid management technologies needed to enable nuclear thermal propulsion powered deep space missions.

  19. Cryogenic system operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1992-01-01

    This report presents a review of cryogenic system operating experiences, from particle accelerator, fusion experiment, space research, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of cryogenic component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with cryogenic systems are discussed, including ozone formation, effects of spills, and modeling spill behavior. This information should be useful to fusion system designers and safety analysts, such as the team working on the International Thermonuclear Experimental Reactor design.

  20. Spacecraft-borne long life cryogenic refrigeration: Status and trends

    NASA Technical Reports Server (NTRS)

    Johnson, A. L.

    1983-01-01

    The status of cryogenic refrigerator development intended for, or possibly applicable to, long life spacecraft-borne application is reviewed. Based on these efforts, the general development trends are identified. Using currently projected technology needs, the various trends are compared and evaluated. The linear drive, non-contacting bearing Stirling cycle refrigerator concept appears to be the best current approach that will meet the technology projection requirements for spacecraft-borne cryogenic refrigerators. However, a multiply redundant set of lightweight, moderate life, moderate reliability Stirling cycle cryogenic refrigerators using high-speed linear drive and sliding contact bearings may possibly suffice.

  1. Demonstration of Fuel Hot-Spot Pressure in Excess of 50 Gbar for Direct-Drive, Layered Deuterium-Tritium Implosions on OMEGA

    NASA Astrophysics Data System (ADS)

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; Collins, T. J. B.; Craxton, R. S.; Davis, A. K.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Frenje, J. A.; Froula, D. H.; Gatu Johnson, M.; Glebov, V. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Jacobs-Perkins, D.; Janezic, R.; Karasik, M.; Keck, R. L.; Kelly, J. H.; Kessler, T. J.; Knauer, J. P.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Obenschain, S. P.; Petrasso, R. D.; Radha, P. B.; Rice, B.; Rosenberg, M. J.; Schmitt, A. J.; Schmitt, M. J.; Seka, W.; Shmayda, W. T.; Shoup, M. J.; Shvydky, A.; Skupsky, S.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Woo, K. M.; Yaakobi, B.; Zuegel, J. D.

    2016-07-01

    A record fuel hot-spot pressure Phs=56 ±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium-tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility, these implosions achieved a Lawson parameter ˜60 % of the value required for ignition [A. Bose et al., Phys. Rev. E 93, LM15119ER (2016)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is approximately 40% lower. Three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  2. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

    DOE PAGES

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; ...

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40%more » lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.« less

  3. Demonstration of fuel hot-spot pressure in excess of 50 Gbar for direct-drive, layered deuterium-tritium implosions on OMEGA

    SciTech Connect

    Regan, S. P.; Goncharov, V. N.; Igumenshchev, I. V.; Sangster, T. C.; Betti, R.; Bose, A.; Boehly, T. R.; Bonino, M. J.; Campbell, E. M.; Cao, D.; Collins, T. J. B.; Craxton, R. S.; Davis, A. K.; Delettrez, J. A.; Edgell, D. H.; Epstein, R.; Forrest, C. J.; Frenje, J. A.; Froula, D. H.; Gatu Johnson, M.; Glebov, V. Yu.; Harding, D. R.; Hohenberger, M.; Hu, S. X.; Jacobs-Perkins, D.; Janezic, R.; Karasik, M.; Keck, R. L.; Kelly, J. H.; Kessler, T. J.; Knauer, J. P.; Kosc, T. Z.; Loucks, S. J.; Marozas, J. A.; Marshall, F. J.; McCrory, R. L.; McKenty, P. W.; Meyerhofer, D. D.; Michel, D. T.; Myatt, J. F.; Obenschain, S. P.; Petrasso, R. D.; Radha, P. B.; Rice, B.; Rosenberg, M. J.; Schmitt, A. J.; Schmitt, M. J.; Seka, W.; Shmayda, W. T.; Shoup, III, M. J.; Shvydky, A.; Skupsky, S.; Solodov, A. A.; Stoeckl, C.; Theobald, W.; Ulreich, J.; Wittman, M. D.; Woo, K. M.; Yaakobi, B.; Zuegel, J. D.

    2016-07-07

    A record fuel hot-spot pressure Phs = 56±7 Gbar was inferred from x-ray and nuclear diagnostics for direct-drive inertial confinement fusion cryogenic, layered deuterium–tritium implosions on the 60-beam, 30-kJ, 351-nm OMEGA Laser System. When hydrodynamically scaled to the energy of the National Ignition Facility (NIF), these implosions achieved a Lawson parameter ~60% of the value required for ignition [A. Bose et al., Phys. Rev. E (in press)], similar to indirect-drive implosions [R. Betti et al., Phys. Rev. Lett. 114, 255003 (2015)], and nearly half of the direct-drive ignition-threshold pressure. Relative to symmetric, one-dimensional simulations, the inferred hot-spot pressure is ~40% lower. Furthermore, three-dimensional simulations suggest that low-mode distortion of the hot spot seeded by laser-drive nonuniformity and target-positioning error reduces target performance.

  4. Strategic Improvements to TSA Spot Program

    DTIC Science & Technology

    2015-03-01

    Administration’s Screening Passengers by Observation Techniques (SPOT) program analyzes the Government Accountability Office (GAO) and Office of Inspector...INTENTIONALLY LEFT BLANK iv ABSTRACT This study of Transportation Security Administration’s Screening Passengers by Observation Techniques ...area SME subject matter expert SPOT screening passengers by observation techniques TAC threat assessment capabilities TAD threat assessment

  5. Hot Spot Removal System: System description

    SciTech Connect

    1997-09-01

    Hazardous wastes contaminated with radionuclides, chemicals, and explosives exist across the Department of Energy complex and need to be remediated due to environmental concerns. Currently, an opportunity is being developed to dramatically reduce remediation costs and to assist in the acceleration of schedules associated with these wastes by deploying a Hot Spot Removal System. Removing the hot spot from the waste site will remove risk driver(s) and enable another, more cost effective process/option/remedial alternative (i.e., capping) to be applied to the remainder of the site. The Hot Spot Removal System consists of a suite of technologies that will be utilized to locate and remove source terms. Components of the system can also be used in a variety of other cleanup activities. This Hot Spot Removal System Description document presents technologies that were considered for possible inclusion in the Hot Spot Removal System, technologies made available to the Hot Spot Removal System, industrial interest in the Hot Spot Removal System`s subsystems, the schedule required for the Hot Spot Removal System, the evaluation of the relevant technologies, and the recommendations for equipment and technologies as stated in the Plan section.

  6. HotSpot Software Test Plan

    SciTech Connect

    Walker, H; Homann, S G

    2009-03-12

    This Software Test Plan (STP) describes the procedures used to verify and validate that the HotSpot Health Physics Codes meet the requirements of its user base, which includes: (1) Users of the PC version of HotSpot conducting consequence assessment, hazard assessment and safety analysis calculations; and (2) Users of the NARAC Web and iClient software tools, which allow users to run HotSpot for consequence assessment modeling. This plan is intended to meet Critical Recommendation 2 from the Software Evaluation of HotSpot and DOE Safety Software Toolbox Recommendation for inclusion of HotSpot in the Department of Energy (DOE) Safety Software Toolbox. These users and sponsors of the HotSpot software and the organizations they represent constitute the intended audience for this document. HotSpot software is maintained for the Department of Energy Office of Emergency Operations by the National Atmospheric Release Advisory Center (NARAC) at Lawrence Livermore National Laboratory (LLNL). An overview of HotSpot and NARAC are provided.

  7. Rocky Mountain Spotted Fever in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We describe the first molecular confirmation of Rickettsia rickettsii, the cause of Rocky Mountain spotted fever (RMSF), from a tick vector, Amblyomma cajennense, and from a cluster of fatal spotted fever cases in Argentina. Questing A. cajennense ticks were collected at or near sites of presumed or...

  8. Rocky Mountain spotted fever in children.

    PubMed

    Woods, Charles R

    2013-04-01

    Rocky Mountain spotted fever is typically undifferentiated from many other infections in the first few days of illness. Treatment should not be delayed pending confirmation of infection when Rocky Mountain spotted fever is suspected. Doxycycline is the drug of choice even for infants and children less than 8 years old.

  9. Rocky Mountain spotted fever in Argentina

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cases of epidemic typhus have been documented in Argentina since 1919; however, no confirmed reports of spotted fever rickettsiosis were described in this country until 1999. We describe the first molecular confirmation of Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever (R...

  10. Rocky Mountain Spotted Fever: Statistics and Epidemiology

    MedlinePlus

    ... Search The CDC Cancel Submit Search The CDC Rocky Mountain Spotted Fever (RMSF) Note: Javascript is disabled or is not ... message, please visit this page: About CDC.gov . Rocky Mountain Spotted Fever (RMSF) Symptoms, Diagnosis, and Treatment Statistics and Epidemiology ...

  11. Habitat Suitability Index Models: Spotted seatrout

    USGS Publications Warehouse

    Kostecki, Paul T.

    1984-01-01

    The estuarine spotted seatrout, a primarily estuarine species, is one of the most important sport and commercial fishes in coastal Gulf of Mexico waters (Arnold et a1. 1976). Spotted seatrout rank second by weight in catches by U.S. saltwater sport fishermen (National Marine Fisheries Services 1981) .

  12. Thermal conductivity of silver loaded conductive epoxy from cryogenic to ambient temperature and its application for precision cryogenic noise measurements

    NASA Astrophysics Data System (ADS)

    Amils, Ricardo I.; Gallego, Juan Daniel; Sebastián, José Luis; Muñoz, Sagrario; Martín, Agustín; Leuther, Arnulf

    2016-06-01

    The pressure to increase the sensitivity of instrumentation has pushed the use of cryogenic Low Noise Amplifier (LNA) technology into a growing number of fields. These areas range from radio astronomy and deep space communications to fundamental physics. In this context manufacturing for cryogenic environments requires a proper thermal knowledge of the materials to be able to achieve adequate design behavior. In this work, we present experimental measurements of the thermal conductivity of a silver filled conductive epoxy (EPO-TEK H20E) which is widely used in cryogenic electronics applications. The characterization has been made using a sample preparation which mimics the practical use of this adhesive in the fabrication of cryogenic devices. We apply the data obtained to a detailed analysis of the effects of the conductive epoxy in a monolithic thermal noise source used for high accuracy cryogenic microwave noise measurements. In this application the epoxy plays a fundamental role since its limited thermal conductivity allows heating the chip with relatively low power. To our knowledge, the cryogenic thermal conductivity data of this epoxy has not been reported before in the literature in the 4-300 K temperature range. A second non-conductive epoxy (Gray Scotch-Weld 2216 B/A), also widely used in cryogenic applications, has been measured in order to validate the method by comparing with previous published data.

  13. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color....

  14. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color....

  15. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color....

  16. 7 CFR 28.413 - Middling Light Spotted Color.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color....

  17. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color....

  18. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color....

  19. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color....

  20. 7 CFR 28.415 - Low Middling Light Spotted Color.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Low Middling Light Spotted Color. 28.415 Section 28... Spotted Color. Low Middling Light Spotted Color is color which in spot or color, or both, is between Low Middling Color and Low Middling Spotted Color....

  1. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color....

  2. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color....

  3. 7 CFR 28.413 - Middling Light Spotted Color.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color....

  4. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color....

  5. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color....

  6. 7 CFR 28.413 - Middling Light Spotted Color.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color....

  7. 7 CFR 28.413 - Middling Light Spotted Color.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 2 2012-01-01 2012-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between Middling Color and Middling Spotted Color....

  8. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color....

  9. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color....

  10. 7 CFR 28.411 - Good Middling Light Spotted Color.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Good Middling Light Spotted Color. 28.411 Section 28... Light Spotted Color. Good Middling Light Spotted Color is color which in spot or color, or both, is between Good Middling Color and Good Middling Spotted Color....

  11. 7 CFR 28.412 - Strict Middling Light Spotted Color.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false Strict Middling Light Spotted Color. 28.412 Section 28... Light Spotted Color. Strict Middling Light Spotted Color is color which in spot or color, or both, is between Strict Middling Color and Strict Middling Spotted Color....

  12. 7 CFR 28.413 - Middling Light Spotted Color.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Middling Light Spotted Color. 28.413 Section 28.413... REGULATIONS COTTON CLASSING, TESTING, AND STANDARDS Standards Light Spotted Cotton § 28.413 Middling Light Spotted Color. Middling Light Spotted Color is color which in spot or color, or both, is between...

  13. 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).

  14. On a cryogenic noble gas ion catcher

    NASA Astrophysics Data System (ADS)

    Dendooven, P.; Purushothaman, S.; Gloos, K.

    2006-03-01

    In situ purification of the gas used as stopping medium in a noble gas ion catcher by operating the device at low temperatures of 60-150 K was investigated. Alpha-decay recoil ions from a 223Ra source served as energetic probes. The combined ion survival and transport efficiencies for 219Rn ions saturated below about 90 K, reaching 28.7(17)% in helium, 22.1(13)% in neon, and 17.0(10)% in argon. These values may well reflect the charge exchange and stripping cross-sections during the slowing down of the ions, and thus represent a fundamental upper limit for the efficiency of noble gas ion catcher devices. We suggest the cryogenic noble gas ion catcher as a technically simpler alternative to the ultra-high purity noble gas ion catcher operating at room temperature.

  15. Development of Large Cryogenic Semiconductor Detectors

    SciTech Connect

    Mandic, Vuk

    2016-12-09

    This project aims at developing large cryogenic semiconductor detectors for applications in particle physics and more broadly. We have developed a 150 mm diameter, 43 mm thick, Si-based detector that measures ionization released in an interaction of a particle inside the silicon crystal of high purity, operated at 30 mK temperature. We demonstrated that such a detector can be used to measure recoil energies on the keV scale, and that its stable operation can be maintained indefinitely. Detectors of this type could therefore be used in the fields of direct dark matter searches, coherent neutrino scattering measurements, X-ray observations, as well as in broader applications such as homeland security.

  16. Cryogenic system for a superconducting spectrometer

    SciTech Connect

    Porter, J.

    1983-08-01

    The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable, pool boiling design to provide a maximum particle bending field of 3 tesla. This paper describes the cryogenic facility including helium refrigeration, gas management, liquid nitrogen system, and the overall control strategy. The system normally operates with a 4K heat load of 150 watts; the LN/sub 2/ circuits absorb an additional 4000 watts. 80K intercept control is by an LSI 11 computer. Total available refrigeration at 4K is 400 watts using reciprocating expanders at the 20K and 4K level. The minicomputer has the capability of optimizing overall utility input cost by varying operating points. A hybrid of pneumatic, analog, and digital control is successful in providing full time unattended operation. The 7m diameter magnet/cryostat assembly is rotatable through 180 degrees to provide a variety of spectrometer orientations.

  17. Cryogenic system for a superconducting spectrometer

    SciTech Connect

    Porter, J.

    1983-03-01

    The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable, pool boiling design to provide a maximum particle bending field of 3 tesla. This paper describes the cryogenic facility including helium refrigeration, gas management, liquid nitrogen system, and the overall control strategy. The system normally operates with a 4 K heat load of 150 watts; the LN/sub 2/ circuits absorb an additional 4000 watts. 80K intercept control is by an LSI 11 computer. Total available refrigeration at 4K is 400 watts using reciprocating expanders at the 20K and 4K level. The minicomputer has the capability of optimizing overall utility input cost by varying operating points. A hybrid of pneumatic, analog, and digital control is successful in providing full time unattended operation. The 7m diameter magnet/cryostat assembly is rotatable through 180 degrees to provide a variety of spectrometer orientations.

  18. Cryogenic system for a superconducting spectrometer

    NASA Astrophysics Data System (ADS)

    Porter, J.

    1983-03-01

    The Heavy Ion Spectrometer System (HISS) relies upon superconducting coils of cryostable, pool boiling design to provide a maximum particle bending field of 3 tesla. The cryogenic facility including helium refrigeration, gas management, liquid nitrogen system, and the overall control strategy are described. The system normally operates with a 4 K heat load of 150 watts; the LN2 circuits absorb an additional 4000 watts. The 80K intercept control is by an LSI 11 computer. Total available refrigeration at 4K is 400 watts using reciprocating expanders at the 20K and 4K level. The minicomputer has the capability of optimizing overall utility input cost by varying operating points. A hybrid of pneumatic, analog, and digital control is successful in providing full time unattended operation. The 7m diameter magnet/cryostat assembly is rotatable through 180 degrees to provide a variety of spectrometer orientations.

  19. Nuclear Cryogenic Propulsion Stage Affordable Development Strategy

    NASA Technical Reports Server (NTRS)

    Doughty, Glen E.; Gerrish, H. P.; Kenny, R. J.

    2014-01-01

    The development of nuclear power for space use in nuclear thermal propulsion (NTP) systems will involve significant expenditures of funds and require major technology development efforts. The development effort must be economically viable yet sufficient to validate the systems designed. Efforts are underway within the National Aeronautics and Space Administration's (NASA) Nuclear Cryogenic Propulsion Stage Project (NCPS) to study what a viable program would entail. The study will produce an integrated schedule, cost estimate and technology development plan. This will include the evaluation of various options for test facilities, types of testing and use of the engine, components, and technology developed. A "Human Rating" approach will also be developed and factored into the schedule, budget and technology development approach.

  20. Dissipative cryogenic filters with zero dc resistance.

    PubMed

    Bluhm, Hendrik; Moler, Kathryn A

    2008-01-01

    The authors designed, implemented, and tested cryogenic rf filters with zero dc resistance, based on wires with a superconducting core inside a resistive sheath. The superconducting core allows low frequency currents to pass with negligible dissipation. Signals above the cutoff frequency are dissipated in the resistive part due to their small skin depth. The filters consist of twisted wire pairs shielded with copper tape. Above approximately 1 GHz, the attenuation is exponential in omega, as typical for skin depth based rf filters. By using additional capacitors of 10 nF per line, an attenuation of at least 45 dB above 10 MHz can be obtained. Thus, one single filter stage kept at mixing chamber temperature in a dilution refrigerator is sufficient to attenuate room temperature black body radiation to levels corresponding to 10 mK above about 10 MHz.