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.

Cryogenic motion performances of a piezoelectric single crystal micromotor

NASA Astrophysics Data System (ADS)

Li, Xiaotian; Wu, Yuting; Chen, Zhijiang; Wei, Xiaoyong; Luo, Haosu; Dong, Shuxiang

2014-04-01

This study investigates the cryogenic performances of a millimeter-size piezoelectric ultrasonic linear micromotor. The piezoelectric vibrator of the micromotor is made of Pb(In1/2Nb1/2)O3 -Pb(Mg1/3Nb2/3)-PbTiO3 single crystal and operated in first-bending wobbling mode. Experiments show that the piezoelectric single crystal micromotor works effectively even at extremely low temperature of -175 °C, although its resonance peaks vary with temperature significantly. This work confirms the feasibility of cryogenic operation of the piezo-micromotor, which is meaningful for aerospace or superconducting microwave application.

Validation and performance of the LHC cryogenic system through commissioning of the first sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serio, L.; Bouillot, A.; Casas-Cubillos, J.

2007-12-01

The cryogenic system [1] for the Large Hadron Collider accelerator is presently in its final phase of commissioning at nominal operating conditions. The refrigeration capacity for the LHC is produced using eight large cryogenic plants and eight 1.8 K refrigeration units installed on five cryogenic islands. Machine cryogenic equipment is installed in a 26.7-km circumference ring deep underground tunnel and are maintained at their nominal operating conditions via a distribution system consisting of transfer lines, cold interconnection boxes at each cryogenic island and a cryogenic distribution line. The functional analysis of the whole system during all operating conditions was establishedmore » and validated during the first sector commissioning in order to maximize the system availability. Analysis, operating modes, main failure scenarios, results and performance of the cryogenic system are presented.« less

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.

Characterisation of diode-connected SiGe BiCMOS HBTs for space applications

NASA Astrophysics Data System (ADS)

Venter, Johan; Sinha, Saurabh; Lambrechts, Wynand

2016-02-01

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

Performance tests of a cryogenic hybrid magnetic bearing for turbopumps

NASA Technical Reports Server (NTRS)

Dirusso, Eliseo; Brown, Gerald V.

1992-01-01

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

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.

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

PubMed

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

2004-11-19

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

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

NASA Astrophysics Data System (ADS)

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

2008-03-01

Thermal conductivity testing under actual-use conditions is a key to understanding how cryogenic thermal insulation systems perform in regard to engineering, economics, and materials factors. The Cryogenics Test Laboratory at NASA's Kennedy Space Center tested a number of bulk-fill insulation materials, including aerogel beads, glass bubbles, and perlite powder, using a new cylindrical cryostat. Boundary temperatures for the liquid nitrogen boiloff method were 78 K and 293 K. Tests were performed as a function of cold vacuum pressure under conditions ranging from high vacuum to no vacuum. Results were compared with those from complementary test methods in the range of 20 K to 300 K. Various testing techniques are required to completely understand the operating performance of a material and to provide data for answers to design engineering questions.

Process simulations for the LCLS-II cryogenic systems

NASA Astrophysics Data System (ADS)

Ravindranath, V.; Bai, H.; Heloin, V.; Fauve, E.; Pflueckhahn, D.; Peterson, T.; Arenius, D.; Bevins, M.; Scanlon, C.; Than, R.; Hays, G.; Ross, M.

2017-12-01

Linac Coherent Light Source II (LCLS-II), a 4 GeV continuous-wave (CW) superconducting electron linear accelerator, is to be constructed in the existing two mile Linac facility at the SLAC National Accelerator Laboratory. The first light from the new facility is scheduled to be in 2020. The LCLS-II Linac consists of thirty-five 1.3 GHz and two 3.9 GHz superconducting cryomodules. The Linac cryomodules require cryogenic cooling for the super-conducting niobium cavities at 2.0 K, low temperature thermal intercept at 5.5-7.5 K, and a thermal shield at 35-55 K. The equivalent 4.5 K refrigeration capacity needed for the Linac operations range from a minimum of 11 kW to a maximum of 24 kW. Two cryogenic plants with 18 kW of equivalent 4.5 K refrigeration capacity will be used for supporting the Linac cryogenic cooling requirements. The cryogenic plants are based on the Jefferson Lab’s CHL-II cryogenic plant design which uses the “Floating Pressure” design to support a wide variation in the cooling load. In this paper, the cryogenic process for the integrated LCLS-II cryogenic system and the process simulation for a 4.5 K cryoplant in combination with a 2 K cold compressor box, and the Linac cryomodules are described.

Thermal Performance of Cryogenic Multilayer Insulation at Various Layer Spacings

NASA Technical Reports Server (NTRS)

Johnson, Wesley Louis

2010-01-01

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

Lifetime testing results and diagnostic performance prediction of linear coolers at Thales Cryogenics

NASA Astrophysics Data System (ADS)

van der Weijden, H.; Benschop, T.; van de Groep, W.; Willems, D.

2011-06-01

Thales Cryogenics (TCBV) has an extensive background in delivering long-life cryogenic coolers for military, civil and space programs. During the last years many technical improvements have increased the lifetime of coolers resulting in significantly higher MTTF's. Lifetime endurance tests are used to validate these performance increases. An update will be given on lifetime test of a selection of TCBV's coolers. MTTF figures indicate the statistical average lifetimes for a large population of coolers. However, for the user of IR camera's and spectrometers a detailed view on the performance of an individual cooler and the possible impact of its performance degradation during its lifetime is very important. Thales Cryogenics is developing Cooler Diagnostic Software (CDS), which can be implemented in the firmware of its DSP based cooler drive electronics. With this implemented software the monitoring of the main cooler parameters during the lifetime in the equipment will be possible, including the prediction of the expected cooler performance availability. Based on this software it will be possible to analyze the status of the cooler inside the equipment and, supported by the lifetime knowledge at Thales Cryogenics, make essential choices on the maintenance of equipment and the replacement of coolers. In the paper, we will give an overview of potential situations in which such a predictive algorithm can be used. We will present the required interaction with future users to make an optimal interaction and interpretation of the generated data possible.

Improving cryogenic deuterium–tritium implosion performance on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sangster, T. C.; Goncharov, V. N.; Betti, R.

2013-05-15

A flexible direct-drive target platform is used to implode cryogenic deuterium–tritium (DT) capsules on the OMEGA laser [Boehly et al., Opt. Commun. 133, 495 (1997)]. The goal of these experiments is to demonstrate ignition hydrodynamically equivalent performance where the laser drive intensity, the implosion velocity, the fuel adiabat, and the in-flight aspect ratio (IFAR) are the same as those for a 1.5-MJ target [Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] designed to ignite on the National Ignition Facility [Hogan et al., Nucl. Fusion 41, 567 (2001)]. The results from a series of 29 cryogenic DT implosions are presented.more » The implosions were designed to span a broad region of design space to study target performance as a function of shell stability (adiabat) and implosion velocity. Ablation-front perturbation growth appears to limit target performance at high implosion velocities. Target outer-surface defects associated with contaminant gases in the DT fuel are identified as the dominant perturbation source at the ablation surface; performance degradation is confirmed by 2D hydrodynamic simulations that include these defects. A trend in the value of the Lawson criterion [Betti et al., Phys. Plasmas 17, 058102 (2010)] for each of the implosions in adiabat–IFAR space suggests the existence of a stability boundary that leads to ablator mixing into the hot spot for the most ignition-equivalent designs.« less

Improving cryogenic deuterium tritium implosion performance on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sangster, T. C.; Goncharov, V. N.; Betti, R.

2013-01-01

A flexible direct-drive target platform is used to implode cryogenic deuterium–tritium (DT) capsules on the OMEGA laser [Boehly et al., Opt. Commun. 133, 495 (1997)]. The goal of these experiments is to demonstrate ignition hydrodynamically equivalent performance where the laser drive intensity, the implosion velocity, the fuel adiabat, and the in-flight aspect ratio (IFAR) are the same as those for a 1.5-MJ target [Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] designed to ignite on the National Ignition Facility [Hogan et al., Nucl. Fusion 41, 567 (2001)]. The results from a series of 29 cryogenic DT implosions are presented.more » The implosions were designed to span a broad region of design space to study target performance as a function of shell stability (adiabat) and implosion velocity. Ablation-front perturbation growth appears to limit target performance at high implosion velocities. Target outer-surface defects associated with contaminant gases in the DT fuel are identified as the dominant perturbation source at the ablation surface; performance degradation is confirmed by 2D hydrodynamic simulations that include these defects. A trend in the value of the Lawson criterion [Betti et al., Phys. Plasmas 17, 058102 (2010)] for each of the implosions in adiabat–IFAR space suggests the existence of a stability boundary that leads to ablator mixing into the hot spot for the most ignition-equivalent designs.« less

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.

Performance and Reliability of Solid Tantalum Capacitors at Cryogenic Conditions

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2006-01-01

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

Thermal Performance of Cryogenic Piping Multilayer Insulation in Actual Field Installations

NASA Technical Reports Server (NTRS)

Fesmire, J.; Augustnynowicz, S.; Thompson, K. (Technical Monitor)

2002-01-01

A standardized way of comparing the thermal performance of different pipelines in different sizes is needed. Vendor data for vacuum-insulated piping are typically given in heat leak rate per unit length (W/m) for a specific diameter pipeline. An overall k-value for actual field installations (k(sub oafi)) is therefore proposed as a more generalized measure for thermal performance comparison and design calculation. The k(sub oafi) provides a direct correspondence to the k-values reported for insulation materials and illustrates the large difference between ideal multilayer insulation (MLI) and actual MLI performance. In this experimental research study, a section of insulated piping was tested under cryogenic vacuum conditions, including simulated spacers and bending. Several different insulation systems were tested using a 1-meter-long cylindrical cryostat test apparatus. The simulated spacers tests showed significant degradation in the thermal performance of a given insulation system. An 18-meter-long pipeline test apparatus is now in operation at the Cryogenics Test Laboratory, NASA Kennedy Space Center, for conducting liquid nitrogen thermal performance tests.

Qualification and cryogenic performance of cryomodule components at CEBAF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heckman, J.; Macha, K.; Fischer, J.

1996-12-31

At CEBAF an electron beam is accelerated by superconducting resonant niobium cavities which are operated submerged in superfluid helium. The accelerator has 42 1/4 cryomodules, each containing eight cavities. The qualification and design of components for the cryomodules under went stringent testing and evaluation for acceptance. Indium wire seals are used between the cavity and helium vessel interface to make a superfluid helium leak tight seal. Each cavity is equipped with a mechanical tuner assembly designed to stretch and compress the cavities. Two rotary feedthroughs are used to operate each mechanical tuner assembly. Ceramic feedthroughs not designed for super-fluid weremore » qualified for tuner and cryogenic instrumentation. To ensure long term integrity of the machine special attention is required for material specifications and machine processes. The following is to share the qualification methods, design and performance of the cryogenic cryomodule components.« less

Investigations on Absorber Materials at Cryogenic Temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marhauser, Frank; Elliott, Thomas; Rimmer, Robert

2009-05-01

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

Linac cryogenic distribution system maintenance and upgrades at JLab

NASA Astrophysics Data System (ADS)

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

2014-01-01

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

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.

Automatic PID Control Loops Design for Performance Improvement of Cryogenic Turboexpander

NASA Astrophysics Data System (ADS)

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

2015-04-01

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

Thermoelectric Performance of Na-Doped GeSe

PubMed Central

2017-01-01

Recently, hole-doped GeSe materials have been predicted to exhibit extraordinary thermoelectric performance owing largely to extremely low thermal conductivity. However, experimental research on the thermoelectric properties of GeSe has received less attention. Here, we have synthesized polycrystalline Na-doped GeSe compounds, characterized their crystal structure, and measured their thermoelectric properties. The Seebeck coefficient decreases with increasing Na content up to x = 0.01 due to an increase in the hole carrier concentration and remains roughly constant at higher concentrations of Na, consistent with the electrical resistivity variation. However, the electrical resistivity is large for all samples, leading to low power factors. Powder X-ray diffraction and scanning electron microscopy/energy-dispersive spectrometry results show the presence of a ternary impurity phase within the GeSe matrix for all doped samples, which suggests that the optimal carrier concentration cannot be reached by doping with Na. Nevertheless, the lattice thermal conductivity and carrier mobility of GeSe is similar to those of polycrystalline samples of the leading thermoelectric material SnSe, leading to quality factors of comparable magnitude. This implies that GeSe shows promise as a thermoelectric material if a more suitable dopant can be found. PMID:29302637

High-performance Ge p-i-n photodetector on Si substrate

NASA Astrophysics Data System (ADS)

Chen, Li-qun; Huang, Xiang-ying; Li, Min; Huang, Yan-hua; Wang, Yue-yun; Yan, Guang-ming; Li, Cheng

2015-05-01

High-performance and tensile-strained germanium (Ge) p-i-n photodetector is demonstrated on Si substrate. The epitaxial Ge layers were prepared in an ultrahigh vacuum chemical vapor deposition (UHV-CVD) system using low temperature Ge buffer technique. The devices were fabricated by in situ doping and using Si as passivation layer between Ge and metal, which can improve the ohmic contact and realize the high doping. The results show that the dark current of the photodetector with diameter of 24 μm is about 2.5×10-7 μA at the bias voltage of -1 V, and the optical responsivity is 0.1 A/W at wavelength of 1.55 μm. The 3 dB bandwidth (BW) of 4 GHz is obtained for the photodetector with diameter of 24 μm at reverse bias voltage of 1 V. The long diffusion time of minority carrier in n-type Ge and the large contact resistance in metal/Ge contacts both affect the performance of Ge photodetectors.

Boosting the optical performance and commutation speed of phototransistor using SiGe/Si/Ge tunneling structure

NASA Astrophysics Data System (ADS)

Ferhati, H.; Djeffal, F.

2018-06-01

In this paper, a new optically controlled tunneling field effect transistor (OC-TFET) based on SiGe/Si/Ge hetero-channel is proposed to improve optical commutation speed and reduce power consumption. An exhaustive study of the device switching behavior associated with different hetero-channel structures has been carried out using an accurate numerical simulation. Moreover, a new figure of Merit (FoM) parameter called optical swing factor that describes the phototransistor optical commutation speed is proposed. We demonstrate that the band-to-band tunneling effect can be beneficial for improving the device optical commutation speed. The impact of the Ge mole fraction of the SiGe source region on the device FoMs is investigated. It is found that the optimized design with 40% of Ge content offers the opportunity to overcome the trade-off between ultrafast and very sensitive photoreceiver performance, where it yields 48 mV/dec of optical swing factor and 155 dB of I ON /I OFF ratio. An overall performance comparison between the proposed OC-TFET device and the conventional designs is performed, where the proposed structure ensures high optical detectivity for very low optical powers (sub-1pW) as compared to that of the conventional counterparts. Therefore, the proposed OC-TFET provides the possibility for bridging the gap between improved optical commutation speed and reduced power consumption, which makes it a potential alternative for high-performance inter-chip data communication applications.

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.

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

NASA Astrophysics Data System (ADS)

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

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

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

NASA Astrophysics Data System (ADS)

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

2017-02-01

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

MOSFET's for Cryogenic Amplifiers

NASA Technical Reports Server (NTRS)

Dehaye, R.; Ventrice, C. A.

1987-01-01

Study seeks ways to build transistors that function effectively at liquid-helium temperatures. Report discusses physics of metaloxide/semiconductor field-effect transistors (MOSFET's) and performances of these devices at cryogenic temperatures. MOSFET's useful in highly sensitive cryogenic preamplifiers for infrared astronomy.

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

PubMed

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

2016-01-01

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

Thermal Performance Testing of Cryogenic Insulation Systems

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

Cryogenic Moisture Apparatus

NASA Technical Reports Server (NTRS)

Fesmire, James; Smith, Trent; Breakfield, Robert; Baughner, Kevin; Heckle, Kenneth; Meneghelli, Barry

2010-01-01

The Cryogenic Moisture Apparatus (CMA) is designed for quantifying the amount of moisture from the surrounding air that is taken up by cryogenic-tank-insulating material specimens while under typical conditions of use. More specifically, the CMA holds one face of the specimen at a desired low temperature (e.g., the typical liquid-nitrogen temperature of 77 K) while the opposite face remains exposed to humid air at ambient or near-ambient temperature. The specimen is weighed before and after exposure in the CMA. The difference between the "after" and "before" weights is determined to be the weight of moisture absorbed by the specimen. Notwithstanding the term "cryogenic," the CMA is not limited to cryogenic applications: the low test temperature can be any temperature below ambient, and the specimen can be made of any material affected by moisture in air. The CMA is especially well suited for testing a variety of foam insulating materials, including those on the space-shuttle external cryogenic tanks, on other cryogenic vessels, and in refrigerators used for transporting foods, medicines, and other perishables. Testing is important because absorbed moisture not only adds weight but also, in combination with thermal cycling, can contribute to damage that degrades insulating performance. Materials are changed internally when subjected to large sub-ambient temperature gradients.

Disentangling nonradiative recombination processes in Ge micro-crystals on Si substrates

NASA Astrophysics Data System (ADS)

Pezzoli, Fabio; Giorgioni, Anna; Gallacher, Kevin; Isa, Fabio; Biagioni, Paolo; Millar, Ross W.; Gatti, Eleonora; Grilli, Emanuele; Bonera, Emiliano; Isella, Giovanni; Paul, Douglas J.; Miglio, Leo

2016-06-01

We address nonradiative recombination pathways by leveraging surface passivation and dislocation management in μm-scale arrays of Ge crystals grown on deeply patterned Si substrates. The time decay photoluminescence (PL) at cryogenic temperatures discloses carrier lifetimes approaching 45 ns in band-gap engineered Ge micro-crystals. This investigation provides compelling information about the competitive interplay between the radiative band-edge transitions and the trapping of carriers by dislocations and free surfaces. Furthermore, an in-depth analysis of the temperature dependence of the PL, combined with capacitance data and finite difference time domain modeling, demonstrates the effectiveness of GeO2 in passivating the surface of Ge and thus in enhancing the room temperature PL emission.

The Effects of Cryogenic Treatment on Cutting Tools

NASA Astrophysics Data System (ADS)

Kumar, Satish; Khedkar, Nitin K.; Jagtap, Bhushan; Singh, T. P.

2017-08-01

Enhancing the cutting tool life is important and economic factor to reduce the tooling as well as manufacturing cost. The tool life is improved considerably by 92 % after cryogenic treatment. The cryogenic treatment is a one-time permanent, sub-zero heat treatment that entirely changes cross-section of cutting tool. The cryogenic treatment is carried out with deep freezing of cutting tool materials to enhance physical and mechanical properties. The cryogenic treatment improves mechanical such as hardness, toughness and tribological properties such as wear resistance, coefficient of friction, surface finish, dimensional stability and stress relief. The deep cryogenic treatment is the most beneficial treatment applied on cutting tools. The cryogenic treatment is the most advanced heat treatment and popular to improve performance of the cutting tool. The optimization of cryogenic treatment variables is necessary to improve tool life. This study reviews the effects of cryogenic treatment on microstructure, tribological properties of tool steels and machining applications of cutting tool by investigating the surface and performing the surface characterization test like SEM. The economy of cutting tool can be achieved by deep cryogenic treatment.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Champlain, James G.; Ruppalt, Laura B.; Guyette, Andrew C.

2016-06-28

The DC and RF electronic behaviors of GeTe-based phase change material switches as a function of temperature, from 25 K to 375 K, have been examined. In its polycrystalline (ON) state, GeTe behaved as a degenerate p-type semiconductor, exhibiting metal-like temperature dependence in the DC regime. This was consistent with the polycrystalline (ON) state RF performance of the switch, which exhibited low resistance S-parameter characteristics. In its amorphous (OFF) state, the GeTe presented significantly greater DC resistance that varied considerably with bias and temperature. At low biases (<1 V) and temperatures (<200 K), the amorphous GeTe low-field resistance dramatically increased, resulting in exceptionally highmore » amorphous-polycrystalline (OFF-ON) resistance ratios, exceeding 10{sup 9} at cryogenic temperatures. At higher biases and temperatures, the amorphous GeTe exhibited nonlinear current-voltage characteristics that were best fit by a space-charge limited conduction model that incorporates the effect of a defect band. The observed conduction behavior suggests the presence of two regions of localized traps within the bandgap of the amorphous GeTe, located at approximately 0.26–0.27 eV and 0.56–0.57 eV from the valence band. Unlike the polycrystalline state, the high resistance DC behavior of amorphous GeTe does not translate to the RF switch performance; instead, a parasitic capacitance associated with the RF switch geometry dominates OFF state RF transmission.« less

Cryogenic engineering

NASA Astrophysics Data System (ADS)

Beliakov, V. P.

Recent developments and trends in cryogenic engineering are reviewed, with emphasis on the role of cryogenics in power generation, machine building, chemistry, and metallurgy. Several cryogenic systems are described, including air-separation apparatus, cryogenic storage systems, cryothermovacuum devices, and the cryogenic systems of superconducting devices. The theoretical principles underlying the design of cryogenic systems are examined, along with the theory for the processes involved.

Cryogenic ion implantation near amorphization threshold dose for halo/extension junction improvement in sub-30 nm device technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Hugh; Todorov, Stan; Colombeau, Benjamin

2012-11-06

We report on junction advantages of cryogenic ion implantation with medium current implanters. We propose a methodical approach on maximizing cryogenic effects on junction characteristics near the amorphization threshold doses that are typically used for halo implants for sub-30 nm technologies. BF{sub 2}{sup +} implant at a dose of 8 Multiplication-Sign 10{sup 13}cm{sup -2} does not amorphize silicon at room temperature. When implanted at -100 Degree-Sign C, it forms a 30 - 35 nm thick amorphous layer. The cryogenic BF{sub 2}{sup +} implant significantly reduces the depth of the boron distribution, both as-implanted and after anneals, which improves short channelmore » rolloff characteristics. It also creates a shallower n{sup +}-p junction by steepening profiles of arsenic that is subsequently implanted in the surface region. We demonstrate effects of implant sequences, germanium preamorphization, indium and carbon co-implants for extension/halo process integration. When applied to sequences such as Ge+As+C+In+BF{sub 2}{sup +}, the cryogenic implants at -100 Degree-Sign C enable removal of Ge preamorphization, and form more active n{sup +}-p junctions and steeper B and In halo profiles than sequences at room temperature.« less

Experimental study on the thermal hydraulic performance of plate-fin heat exchangers for cryogenic applications

NASA Astrophysics Data System (ADS)

Jiang, Qingfeng; Zhuang, Ming; Zhang, Qiyong; Zhu, Zhigang; Geng, Maofei; Sheng, Linhai; Zhu, Ping

2018-04-01

Efficient and compact plate-fin heat exchangers are critical for large-scale helium liquefaction/refrigeration systems as they constitute major part in the cold box. This study experimentally explores the heat transfer and pressure drop behaviors of helium gas at low temperature in four types of plate-fin channels, namely offset-strip and perforated fins, with different geometrical parameters. A series of cryogenic experiments at approximately liquid nitrogen temperature are carried out to measure the Colburn j factors and Fanning friction f factors with a wide range of Reynolds number. Besides, to reveal the performance variations under different operating temperatures, comparative experiments respectively conducted at room temperature and liquid nitrogen temperature are implemented. The results show that in comparison with the performance data at room temperature, most of j factors are relatively smaller perhaps because the lower aluminum thermal conductivity and higher Prandtl Number at low temperature. Meanwhile, the f factors corresponding to cryogenic conditions exhibit slightly larger even though the core pressure drops show considerable reductions. In contrast to the calculated results from the frequently-used performance curves (Chen and Shen, 1993), the Root Mean Squared Errors of j and f values are correlated within 8.38% and 6.97% for one perforated fin core, 41.29% and 34.97% for three OSF cores, respectively. For OSFs, further comparisons with the previous empirical correlations from literatures are conducted to verify the accuracy of each correlation. Generally, most of the calculated results predict acceptably within the deviations of ±25% for the j factors, while the predicted results express relatively large deviations for the f factors. Therefore, it may be revealed that most of the existing correlations were not able to accurately predict the experimental data in consideration of the performance differences under realistic cryogenic operating

Performance analysis for the cryogenic etalon spectrometer on the Upper Atmospheric Research Satellite

NASA Technical Reports Server (NTRS)

Roche, A. E.; Forney, P. B.; Kumer, J. B.; Naes, L. G.; Nast, T. C.

1983-01-01

The Upper Atmospheric Research Satellite (UARS) program has the objective of providing an 18-month to 2-year platform for observations of the upper atmosphere, giving particular attention to the stratosphere, mesosphere, and lower thermosphere. The primary aims of the mission are related to the measurement of the solar energy input between 120 and 500 km, the acquisition of global maps of the vertical and horizontal distribution of a series of critical trace and minor species, and the investigation of the dynamics of the upper atmosphere. One of several instruments designed to perform neutral species measurements on board the satellite is the Cryogenic Limb Array Etalon Spectrometer (CLAES). The CLAES experiment is concerned with measurements of concentrations of species of interest to the ozone layer balance. Attention is given to the performance requirements of the instrument and the effects of these requirements on the cryogenic design.

Spacelab cryogenic propellant management experiment

NASA Technical Reports Server (NTRS)

Cady, E. C.

1976-01-01

The conceptual design of a Spacelab cryogen management experiment was performed to demonstrate toe desirability and feasibility of subcritical cryogenic fluid orbital storage and supply. A description of the experimental apparatus, definition of supporting requirements, procedures, data analysis, and a cost estimate are included.

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

NASA Astrophysics Data System (ADS)

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

2013-04-01

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

Performance evaluation of cryogenic counter-flow heat exchangers with longitudinal conduction, heat in-leak and property variations

NASA Astrophysics Data System (ADS)

Jiang, Q. F.; Zhuang, M.; Zhu, Z. G.; Y Zhang, Q.; Sheng, L. H.

2017-12-01

Counter-flow plate-fin heat exchangers are commonly utilized in cryogenic applications due to their high effectiveness and compact size. For cryogenic heat exchangers in helium liquefaction/refrigeration systems, conventional design theory is no longer applicable and they are usually sensitive to longitudinal heat conduction, heat in-leak from surroundings and variable fluid properties. Governing equations based on distributed parameter method are developed to evaluate performance deterioration caused by these effects. The numerical model could also be applied in many other recuperators with different structures and, hence, available experimental data are used to validate it. For a specific case of the multi-stream heat exchanger in the EAST helium refrigerator, quantitative effects of these heat losses are further discussed, in comparison with design results obtained by the common commercial software. The numerical model could be useful to evaluate and rate the heat exchanger performance under the actual cryogenic environment.

The performance of a piezoelectric-sensor-based SHM system under a combined cryogenic temperature and vibration environment

NASA Astrophysics Data System (ADS)

Qing, Xinlin P.; Beard, Shawn J.; Kumar, Amrita; Sullivan, Kevin; Aguilar, Robert; Merchant, Munir; Taniguchi, Mike

2008-10-01

A series of tests have been conducted to determine the survivability and functionality of a piezoelectric-sensor-based active structural health monitoring (SHM) SMART Tape system under the operating conditions of typical liquid rocket engines such as cryogenic temperature and vibration loads. The performance of different piezoelectric sensors and a low temperature adhesive under cryogenic temperature was first investigated. The active SHM system for liquid rocket engines was exposed to flight vibration and shock environments on a simulated large booster LOX-H2 engine propellant duct conditioned to cryogenic temperatures to evaluate the physical robustness of the built-in sensor network as well as operational survivability and functionality. Test results demonstrated that the developed SMART Tape system can withstand operational levels of vibration and shock energy on a representative rocket engine duct assembly, and is functional under the combined cryogenic temperature and vibration environment.

SiGe Integrated Circuit Developments for SQUID/TES Readout

NASA Astrophysics Data System (ADS)

Prêle, D.; Voisin, F.; Beillimaz, C.; Chen, S.; Piat, M.; Goldwurm, A.; Laurent, P.

2018-03-01

SiGe integrated circuits dedicated to the readout of superconducting bolometer arrays for astrophysics have been developed since more than 10 years at APC. Whether for Cosmic Microwave Background (CMB) observations with the QUBIC ground-based experiment (Aumont et al. in astro-ph.IM, 2016. arXiv:1609.04372) or for the Hot and Energetic Universe science theme with the X-IFU instrument on-board of the ATHENA space mission (Barret et al. in SPIE 9905, space telescopes & instrumentation 2016: UV to γ Ray, 2016. https://doi.org/10.1117/12.2232432), several kinds of Transition Edge Sensor (TES) (Irwin and Hilton, in ENSS (ed) Cryogenic particle detection, Springer, Berlin, 2005) arrays have been investigated. To readout such superconducting detector arrays, we use time or frequency domain multiplexers (TDM, FDM) (Prêle in JINST 10:C08015, 2016. https://doi.org/10.1088/1748-0221/10/08/C08015) with Superconducting QUantum Interference Devices (SQUID). In addition to the SQUID devices, low-noise biasing and amplification are needed. These last functions can be obtained by using BiCMOS SiGe technology in an Application Specific Integrated Circuit (ASIC). ASIC technology allows integration of highly optimised circuits specifically designed for a unique application. Moreover, we could reach very low-noise and wide band amplification using SiGe bipolar transistor either at room or cryogenic temperatures (Cressler in J Phys IV 04(C6):C6-101, 1994. https://doi.org/10.1051/jp4:1994616). This paper discusses the use of SiGe integrated circuits for SQUID/TES readout and gives an update of the last developments dedicated to the QUBIC telescope and to the X-IFU instrument. Both ASIC called SQmux128 and AwaXe are described showing the interest of such SiGe technology for SQUID multiplexer controls.

Cryogenic readout techniques for germanium detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Inferential Framework for Autonomous Cryogenic Loading Operations

NASA Technical Reports Server (NTRS)

Luchinsky, Dmitry G.; Khasin, Michael; Timucin, Dogan; Sass, Jared; Perotti, Jose; Brown, Barbara

2017-01-01

We address problem of autonomous cryogenic management of loading operations on the ground and in space. As a step towards solution of this problem we develop a probabilistic framework for inferring correlations parameters of two-fluid cryogenic flow. The simulation of two-phase cryogenic flow is performed using nearly-implicit scheme. A concise set of cryogenic correlations is introduced. The proposed approach is applied to an analysis of the cryogenic flow in experimental Propellant Loading System built at NASA KSC. An efficient simultaneous optimization of a large number of model parameters is demonstrated and a good agreement with the experimental data is obtained.

Ge/GeO2-Ordered Mesoporous Carbon Nanocomposite for Rechargeable Lithium-Ion Batteries with a Long-Term Cycling Performance.

PubMed

Zeng, Lingxing; Huang, Xiaoxia; Chen, Xi; Zheng, Cheng; Qian, Qingrong; Chen, Qinghua; Wei, Mingdeng

2016-01-13

Germanium-based nanostructures are receiving intense interest in lithium-ion batteries because they have ultrahigh lithium ion storage ability. However, the Germanium-based anodes undergo the considerably large volume change during the charge/discharge processes, leading to a fast capacity fade. In the present work, a Ge/GeO2-ordered mesoporous carbon (Ge/GeO2-OMC) nanocomposite was successfully fabricated via a facile nanocasting route by using mesoporous carbon as a nanoreactor, and was then used as an anode for lithium-ion batteries. Benefited from its unique three-dimensional "meso-nano" structure, the Ge/GeO2-OMC nanocomposite exhibited large reversible capacity, excellent long-time cycling stability and high rate performance. For instance, a large reversible capacity of 1018 mA h g(-1) was obtained after 100 cycles at a current density of 0.1 A g(-1), which might be attributed to the unique structure of the Ge/GeO2-OMC nanocomposite. In addition, a reversible capacity of 492 mA h g(-1) can be retained when cycled to 500 cycles at a current density of 1 A g(-1).

Kodak AMSD Cryogenic Test Plans

NASA Technical Reports Server (NTRS)

Matthews, Gary; Hammon, John; Barrett, David; Russell, Kevin (Technical Monitor)

2002-01-01

NGST will be an IR based optical system that will operate at cryogenic temperatures. As part of the AMSD program, Kodak must demonstrate the ability of our system to perform at these very cold temperatures. Kodak will discuss the test approach that will be used for cryogenic testing at MSFC's XRCF.

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

NASA Technical Reports Server (NTRS)

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

2003-01-01

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

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.

Subcooling Cryogenic Propellants for Long Duration Space Exploration

NASA Technical Reports Server (NTRS)

Mustafi, Shuvo; Canavan, Edgar; Johnson, Wesley; Kutter, Bernard; Shull, Jeff

2009-01-01

The use of cryogenic propellants such as hydrogen and oxygen is crucial for exploration of the solar system because of their superior specific impulse capability. Future missions may require vehicles with the flexibility to remain in orbit or travel in space for months, necessitating long-term storage of these cryogens. One powerful technique for easing the challenge of cryogenic fluid storage is to remove energy from tlie cryogenic propellant by isobaricly subcooling them below their 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. After launch, even with the use of the best insulation systems, heat will leak into the cold cryogenic propellant tank. However, the large heat capacity available in highly subcooled cryogenic propellants allows them to absorb the energy that leaks into the tank until the cryogen reaches its operational thermodynamic condition. During this period of heating of the subcooled cryogen there will be no 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 many months with minimal mass penalty. Subcooling technologies for cryogenic propellants would thus provide the Exploration Systems Mission Directorate with an enhanced level of mission flexibility. However, there are a few challenges associated with subcooling cryogenic propellants since compact subcooling ground support equipment has not been demonstrated. This paper explores the beneficial impact of subcooling cryogenic propellants on the launch pad for long-term cryogenic propellant storage in space and proposes a novel method for implementing subcooling of cryogenic propellants for spacecraft such as the Ares V Earth Departure Stage (EDS). Analysis indicates that with a careful strategy to handle the

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.

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

NASA Technical Reports Server (NTRS)

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

1971-01-01

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

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.

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

Performance analysis of GeSn-alloy-based multiple quantum well transistor laser

NASA Astrophysics Data System (ADS)

Ranjan, Ravi; Pareek, Prakash; Anwer Askari, Syed Sadique; Das, Mukul K.

2018-02-01

The Group IV Photonics (GFP) which include an alloy of Si, Ge & Sn that gives a direct bandgap material (GeSn, SiGeSn) in near and mid-IR region used as an active material in photonics devices. The multiple quantum well SiGeSn/GeSn transistor laser structure is considered in this paper and performance parameters are evaluated for the same. The result shows that the threshold base current density (2.6 kA/cm2) for the proposed device initially decreases with increasing number of quantum well (QW) and later on it saturates. The current gain and output photon density of the device decreases and increases respectively, with increasing number of QW.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

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.

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

NASA Technical Reports Server (NTRS)

Patterson, Richard L.; Hammoud, Ahmad

2010-01-01

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

Performance of High-Speed PWM Control Chips at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

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.

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.

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

NASA Technical Reports Server (NTRS)

2008-01-01

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

Design theory and performance of cryogenic molecular adsorption refrigeration systems

NASA Technical Reports Server (NTRS)

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

1978-01-01

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

Aqueous Binder Enhanced High-Performance GeP5 Anode for Lithium-Ion Batteries

PubMed Central

He, Jun; Wei, Yaqing; Hu, Lintong; Li, Huiqiao; Zhai, Tianyou

2018-01-01

GeP5 is a recently reported new anode material for lithium ion batteries (LIBs), it holds a large theoretical capacity about 2300 mAh g−1, and a high rate capability due to its bi-active components and superior conductivity. However, it undergoes a large volume change during its electrochemical alloying and de-alloying with Li, a suitable binder is necessary to stable the electrode integrity for improving cycle performance. In this work, we tried to apply aqueous binders LiPAA and NaCMC to GeP5 anode, and compared the difference in electrochemical performance between them and traditional binder PVDF. As can be seen from the test result, GeP5 can keep stable in both common organic solvents and proton solvents such as water and alcohol solvents, it meets the application requirements of aqueous binders. The electrochemistry results show that the use of LiPAA binder can significantly improve the initial Coulombic efficiency, reversible capacity, and cyclability of GeP5 anode as compared to the electrodes based on NaCMC and PVDF binders. The enhanced electrochemical performance of GeP5 electrode with LiPAA binder can be ascribed to the unique high strength long chain polymer structure of LiPAA, which also provide numerous uniform distributed carboxyl groups to form strong ester groups with active materials and copper current collector. Benefit from that, the GeP5 electrode with LiPAA can also exhibit excellent rate capability, and even at low temperature, it still shows attractive electrochemical performance. PMID:29484292

Aqueous Binder Enhanced High-Performance GeP5 Anode for Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

He, Jun; Wei, Yaqing; Hu, Lintong; Li, Huiqiao; Zhai, Tianyou

2018-02-01

GeP5 is a recently reported new anode material for lithium ion batteries (LIBs), it holds a large theoretical capacity about 2300 mAh g-1, and a high rate capability due to its bi-active components and superior conductivity. However, it undergoes a large volume change during its electrochemical alloying and de-alloying with Li, a suitable binder is necessary to stable the electrode integrity for improving cycle performance. In this work, we tried to apply aqueous binders LiPAA and NaCMC to GeP5 anode, and compared the difference in electrochemical performance between them and traditional binder PVDF. As can be seen from the test result, GeP5 can keep stable in both common organic solvents and proton solvents such as water and alcohol solvents, it meets the application requirements of aqueous binders. The electrochemistry results show that the use of LiPAA binder can significantly improve the initial Coulombic efficiency, reversible capacity, and cyclability of GeP5 anode as compared to the electrodes based on NaCMC and PVDF binders. The enhanced electrochemical performance of GeP5 electrode with LiPAA binder can be ascribed to the unique high strength long chain polymer structure of LiPAA, which also provide numerous uniform distributed carboxyl groups to form strong ester groups with active meterials and copper current collector. Benefit from that, the GeP5 electrode with LiPAA can also exhibit excellent rate capability, and even at low temperature, it still shows attractive electrochemical performance.

Process of making cryogenically cooled high thermal performance crystal optics

DOEpatents

Kuzay, Tuncer M.

1992-01-01

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

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 Astrophysics Data System (ADS)

Thienel, Lee; Stouffer, Chuck

1995-09-01

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.

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.

On-orbit cryogenic fluid transfer

NASA Technical Reports Server (NTRS)

Aydelott, J. C.; Gille, J. P.; Eberhardt, R. N.

1984-01-01

A number of future NASA and DOD missions have been identified that will require, or could benefit from resupply of cryogenic liquids in orbit. The most promising approach for accomplishing cryogenic fluid transfer in the weightlessness environment of space is to use the thermodynamic filling technique. This approach involves initially reducing the receiver tank temperature by using several charge hold vent cycles followed by filling the tank without venting. Martin Marietta Denver Aerospace, under contract to the NASA Lewis Research Center, is currently developing analytical models to describe the on orbit cryogenic fluid transfer process. A detailed design of a shuttle attached experimental facility, which will provide the data necessary to verify the analytical models, is also being performed.

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.

Cryogenic insulation standard data and methodologies

NASA Astrophysics Data System (ADS)

Demko, J. A.; Fesmire, J. E.; Johnson, W. L.; Swanger, A. M.

2014-01-01

Although some standards exist for thermal insulation, few address the sub-ambient temperature range and cold-side temperatures below 100 K. Standards for cryogenic insulation systems require cryostat testing and data analysis that will allow the development of the tools needed by design engineers and thermal analysts for the design of practical cryogenic systems. Thus, this critically important information can provide reliable data and methodologies for industrial efficiency and energy conservation. Two Task Groups have been established in the area of cryogenic insulation systems Under ASTM International's Committee C16 on Thermal Insulation. These are WK29609 - New Standard for Thermal Performance Testing of Cryogenic Insulation Systems and WK29608 - Standard Practice for Multilayer Insulation in Cryogenic Service. The Cryogenics Test Laboratory of NASA Kennedy Space Center and the Thermal Energy Laboratory of LeTourneau University are conducting Inter-Laboratory Study (ILS) of selected insulation materials. Each lab carries out the measurements of thermal properties of these materials using identical flat-plate boil-off calorimeter instruments. Parallel testing will provide the comparisons necessary to validate the measurements and methodologies. Here we discuss test methods, some initial data in relation to the experimental approach, and the manner reporting the thermal performance data. This initial study of insulation materials for sub-ambient temperature applications is aimed at paving the way for further ILS comparative efforts that will produce standard data sets for several commercial materials. Discrepancies found between measurements will be used to improve the testing and data reduction techniques being developed as part of the future ASTM International standards.

Performance and Cost Evaluation of Cryogenic Solid Propulsion Systems

NASA Astrophysics Data System (ADS)

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

2002-01-01

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

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.

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

NASA Astrophysics Data System (ADS)

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

2010-04-01

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

Process of making cryogenically cooled high thermal performance crystal optics

DOEpatents

Kuzay, T.M.

1992-06-23

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

JWST NIRSpec Cryogenic Light Shield Mechanism

NASA Technical Reports Server (NTRS)

Hale, Kathleen; Sharma, Rajeev

2006-01-01

The focal plane detectors for the Near-Infrared Spectrometer (NIRSpec) instrument on the James Webb Space Telescope (JWST) require a light tight cover for calibration along with an open field-of-view during ground performance testing within a cryogenic dewar. In order to meet the light attenuation requirements and provide open and closed fields of view without breaking vacuum, a light shield mechanism was designed. This paper describes the details of the light shield mechanism design and test results. Included is information on the labyrinth light path design, motor capability and performance, dry film lubrication, mechanism control, and mechanism cryogenic performance results.

Mechanical testing of large cryogenic structures

NASA Technical Reports Server (NTRS)

Newkirk, Roger; Burriesci, Larry

1990-01-01

The mechanical testing performed on the Cryogenic Limb Array Etalon Spectrometer (CLAES) instrument installed on the Upper Atmosphere Research Satellite is discussed. The CLAES determines temperatures and concentrations of stratospheric minor species as a function of altitude by measuring the atmospheric infrared emission spectra. CLAES is based on a telescope optical system and infrared spectrometer which are cooled with cryogens.

Cryogenic bolometric systems

NASA Astrophysics Data System (ADS)

Kangas, Miikka Matias

The big bang, early galaxy formation, the interstellar medium, and high z galaxy cluster evolution are all science objectives that are studied in the far infrared (FIR). The cosmological parameters that describe the universe are encoded in anisotropies in the Cosmic Microwave Background (CMB), and can be extracted from precision subdegree angular resolution FIR maps. Cryogenic bolometers are well suited for these science objectives, and are evolving rapidly today. A cryogenic bolometric system is made up of a few building blocks, which can be modularized or integrated depending on the maturity of the scientific field they are used for. Integration of systems increases with the maturity of the technology. The basic building blocks are the bolometer, the cryogenics, the dewar, the optics, the filters, and electronics. The electronics can be further subdivided into room temperature back-end and cryogenic front-end electronics. The electronics are often partly integrated into the dewar. The dewar is part of the support structure, and only the subkelvin portion the dewar is referred to as cryogenics here. Each of these can be a sophisticated engineering feat on their own, and this dissertation revolves around the development of several of these elements. The microfabrication sequence for a free standing micromesh detector was developed. Polarization preserving photometer optics and filters were constructed and tested. A test dewar mechanical and optical structure was created to test single pixel photometers prior to mounting in the flight dewar. A modular flight dewar capable of holding an array of photometers and adaptable to a number of different cryogenics schemes and detector arrays was engineered and constructed. A zero gravity dilution refrigerator coil was constructed and tested. A corrugated platelet array concept was designed and tested. Metal mesh filter design and fabrication techniques were developed. Kevlar isolator structures were improved to work in

Cryogenic Temperature-Gradient Foam/Substrate Tensile Tester

NASA Technical Reports Server (NTRS)

Vailhe, Christophe

2003-01-01

The figure shows a fixture for measuring the tensile strength of the bond between an aluminum substrate and a thermally insulating polymeric foam. The specimen is meant to be representative of insulating foam on an aluminum tank that holds a cryogenic liquid. Prior to the development of this fixture, tensile tests of this type were performed on foam/substrate specimens immersed in cryogenic fluids. Because the specimens were cooled to cryogenic temperatures throughout their thicknesses, they tended to become brittle and to fracture at loads below true bond tensile strengths. The present fixture is equipped to provide a thermal gradient from cryogenic temperature at the foam/substrate interface to room temperature on the opposite foam surface. The fixture includes an upper aluminum block at room temperature and a lower aluminum block cooled to -423 F (approx. -253 C) by use of liquid helium. In preparation for a test, the metal outer surface (the lower surface) of a foam/substrate specimen is bonded to the lower block and the foam outer surface (the upper surface) of the specimen is bonded to the upper block. In comparison with the through-the-thickness cooling of immersion testing, the cryogenic-to-room-temperature thermal gradient that exists during testing on this fixture is a more realistic approximation of the operational thermal condition of sprayed insulating foam on a tank of cryogenic liquid. Hence, tensile tests performed on this fixture provide more accurate indications of operational bond tensile strengths. In addition, the introduction of the present fixture reduces the cost of testing by reducing the amount of cryogenic liquid consumed and the time needed to cool a specimen.

Centaur Test Bed (CTB) for Cryogenic Fluid Management

NASA Technical Reports Server (NTRS)

Sakla, Steven; Kutter, Bernard; Wall, John

2006-01-01

Future missions such as NASA s space exploration vision and DOD satellite servicing will require significant increases in the understanding and knowledge of space based cryogenic fluid management (CFM), including the transfer and storage of cryogenic fluids. Existing CFM capabilities are based on flight of upper stage cryogenic vehicles, scientific dewars, a few dedicated flight demonstrations and ground testing. This current capability is inadequate to support development of the CEV cryogenic propulsion system, other aspects of robust space exploration or the refueling of satellite cryo propulsion systems with reasonable risk. In addition, these technologies can provide significant performance increases for missions beyond low-earth orbit to enable manned missions to the Moon and beyond. The Centaur upper-stage vehicle can provide a low cost test platform for performing numerous flight demonstrations of the full breadth of required CFM technologies to support CEV development. These flight demonstrations can be performed as secondary mission objectives using excess LH2 and/or LO2 from the main vehicle propellant tanks following primary spacecraft separation at minimal cost and risk.

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.

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.

Status of the LBNF Cryogenic System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montanari, D.; Adamowski, M.; Bremer, J.

2017-01-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 ton of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team willmore » design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the models of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.« less

Status of the LBNF Cryogenic System

NASA Astrophysics Data System (ADS)

Montanari, D.; Adamowski, M.; Bremer, J.; Delaney, M.; Diaz, A.; Doubnik, R.; Haaf, K.; Hentschel, S.; Norris, B.; Voirin, E.

2017-12-01

The Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An international engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. The expected performance, the functional requirements and the status of the design are also highlighted.

Cryogenic phonon-scintillation detectors with PMT readout for rare event search experiments

NASA Astrophysics Data System (ADS)

Zhang, X.; Lin, J.; Mikhailik, V. B.; Kraus, H.

2016-06-01

Cryogenic phonon-scintillation detectors (CPSD) for rare event search experiments require reliable, efficient and robust photon detectors that can resolve individual photons in a scintillation event. We report on a cryogenic detector containing a scintillating crystal, equipped with an NTD-Ge phonon sensor and a photon detector based on a low-temperature photomultiplier tube (PMT) that is powered by a Cockcroft-Walton generator. Here we present results from the characterisation of two detector modules, one with CaWO4, the other with CaMoO4 as scintillator. The energy resolutions (FWHM) at 122.1 keV for the scintillation/PMT channel are 19.9% and 29.7% respectively for CaWO4 and CaMoO4 while the energy resolutions (FWHM) for the phonon channels are 2.17 keV (1.8%) and 0.97 keV (0.79%). These characteristics compare favourably with other CPSDs currently used in cryogenic rare-event search experiments. The detection module with PMT readout benefits from the implementation of a well-understood, reliable, and commercially available component and improved time resolution, while retaining the major advantages of conventional CPSD, such as high sensitivity, resolving power and discrimination ability.

Astrium Preparation of Future Cryogenic Thrust Chamber Development

NASA Astrophysics Data System (ADS)

Nicolay, Rolf

2002-01-01

The scenarios for future cryogenic propulsion in Europe are mainly governed by cost issues on the one side and performance issues on the other. Certain relationships of the different issues exist to either the application for ELVs or RLVs respectively. Taking into account the limited budgets of the Europeans Agency Market, flexible development strategies are and have to be defined to fulfill both applications requirements. Investigations aiming at identifying the optimum development strategy serving both applications have been performed. Based on the experience of the different cryogenic thrust chamber developments already performed, Astrium worked out a flexible development strategy for future cryogenic thrust chambers in order to: This paper is going to report about this development strategy and the associated derived needs for technological investigations and development work.

Cryogenic immersion microscope

DOEpatents

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.

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.

Cryogenic Fluid Management Technology Development Roadmaps

NASA Technical Reports Server (NTRS)

Stephens, J. R.; Johnson, W. L.

2017-01-01

Advancement in Cryogenic Fluid Management (CFM) Technologies is essential for achieving NASA's future long duration missions. Propulsion systems utilizing cryogens are necessary to achieve mission success. Current State Of the Art (SOA) CFM technologies enable cryogenic propellants to be stored for several hours. However, some envisioned mission architectures require cryogens to be stored for two years or longer. The fundamental roles of CFM technologies are long term storage of cryogens, propellant tank pressure control and propellant delivery. In the presence of heat, the cryogens will "boil-off" over time resulting in excessive pressure buildup, off-nominal propellant conditions, and propellant loss. To achieve long term storage and tank pressure control, the CFM elements will intercept and/or remove any heat from the propulsion system. All functions are required to perform both with and without the presence of a gravitational field. Which CFM technologies are required is a function of the cryogens used, mission architecture, vehicle design and propellant tank size. To enable NASA's crewed mission to the Martian surface, a total of seventeen CFM technologies have been identified to support an In-Space Stage and a Lander/Ascent Vehicle. Recognizing that FY2020 includes a Decision Point regarding the In-Space Stage Architecture, a set of CFM Technology Development Roadmaps have been created identifying the current Technology Readiness Level (TRL) of each element, current technology "gaps", and existing technology development efforts. The roadmaps include a methodical approach and schedule to achieve a flight demonstration in FY2023, hence maturing CFM technologies to TRL 7 for infusion into the In-Space Stage Preliminary Design.

Design of a cryogenic test facility for evaluating the performance of interferometric components of the SPICA/SAFARI instrument

NASA Astrophysics Data System (ADS)

Veenendaal, Ian T.; Naylor, David A.; Gom, Brad G.

2014-08-01

The Japanese SPace Infrared telescope for Cosmology and Astrophysics (SPICA), a 3 m class telescope cooled to ~ 6 K, will provide extremely low thermal background far-infrared observations. An imaging Fourier transform spectrometer (SAFARI) is being developed to exploit the low background provided by SPICA. Evaluating the performance of the interferometer translation stage and key optical components requires a cryogenic test facility. In this paper we discuss the design challenges of a pulse tube cooled cryogenic test facility that is under development for this purpose. We present the design of the cryostat and preliminary results from component characterization and external optical metrology.

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.

Status of the LBNF Cryogenic System

DOE PAGES

Montanari, D.; Adamowski, M.; Bremer, J.; ...

2017-12-30

We present that the Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An internationalmore » engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. Lastly, the expected performance, the functional requirements and the status of the design are also highlighted.« less

Status of the LBNF Cryogenic System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Montanari, D.; Adamowski, M.; Bremer, J.

We present that the Sanford Underground Research Facility (SURF) will host the Deep Underground Neutrino Experiment (DUNE), an international multi-kiloton Long-Baseline neutrino experiment that will be installed about a mile underground in Lead, SD. In the current configuration four cryostats will contain a modular detector and a total of 68,400 tons of ultrapure liquid argon, with a level of impurities lower than 100 parts per trillion of oxygen equivalent contamination. The Long-Baseline Neutrino Facility (LBNF) provides the conventional facilities and the cryogenic infrastructure to support DUNE. The system is comprised of three sub-systems: External/Infrastructure, Proximity and Internal cryogenics. An internationalmore » engineering team will design, manufacture, commission, and qualify the LBNF cryogenic system. This contribution presents the modes of operations, layout and main features of the LBNF cryogenic system. Lastly, the expected performance, the functional requirements and the status of the design are also highlighted.« less

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.

Coupled Cryogenic Thermal and Electrical Models for Transient Analysis of Superconducting Power Devices with Integrated Cryogenic Systems

NASA Astrophysics Data System (ADS)

Satyanarayana, S.; Indrakanti, S.; Kim, J.; Kim, C.; Pamidi, S.

2017-12-01

Benefits of an integrated high temperature superconducting (HTS) power system and the associated cryogenic systems on board an electric ship or aircraft are discussed. A versatile modelling methodology developed to assess the cryogenic thermal behavior of the integrated system with multiple HTS devices and the various potential configurations are introduced. The utility and effectiveness of the developed modelling methodology is demonstrated using a case study involving a hypothetical system including an HTS propulsion motor, an HTS generator and an HTS power cable cooled by an integrated cryogenic helium circulation system. Using the methodology, multiple configurations are studied. The required total cooling power and the ability to maintain each HTS device at the required operating temperatures are considered for each configuration and the trade-offs are discussed for each configuration. Transient analysis of temperature evolution in the cryogenic helium circulation loop in case of a system failure is carried out to arrive at the required critical response time. The analysis was also performed for a similar liquid nitrogen circulation for an isobaric condition and the cooling capacity ratio is used to compare the relative merits of the two cryogens.

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.

Cryogenic Fluid Technologies for Long Duration In-Space Operations

NASA Technical Reports Server (NTRS)

Motil, Susan M.; Tramel, Terri L.

2008-01-01

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

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

PubMed

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

2014-12-21

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

Commissioning the cryogenic system of the first LHC sector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Millet, F.; Claudet, S.; Ferlin, G.

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 commissioningmore » 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.« less

Radiation Requirements and Testing of Cryogenic Thermometers for the Ilc

NASA Astrophysics Data System (ADS)

Barnett, T.; Filippov, Yu. P.; Filippova, E. Yu.; Mokhov, N. V.; Nakao, N.; Klebaner, A. L.; Korenev, S. A.; Theilacker, J. C.; Trenikhina, J.; Vaziri, K.

2008-03-01

Large quantity of cryogenic temperature sensors will be used for operation of the International Linear Collider (ILC). Most of them will be subject to high radiation doses during the accelerator lifetime. Understanding of particle energy spectra, accumulated radiation dose in thermometers and its impact on performance are vital in establishing technical specification of cryogenic thermometry for the ILC. Realistic MARS15 computer simulations were performed to understand the ILC radiation environment. Simulation results were used to establish radiation dose requirements for commercially available cryogenic thermometers. Two types of thermometers, Cernox® and TVO, were calibrated prior to irradiation using different technique. The sensors were subjected then to up to 200 kGy electron beam irradiation with kinetic energy of 5 MeV, a representative of the situation at the ILC operation. A post-irradiation behavior of the sensors was studied. The paper describes the MARS15 model, simulation results, cryogenic test set-up, irradiation tests, and cryogenic test results.

Cryogen Safety Course 8876

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glass, George

2017-06-13

Cryogenics (from the Greek word κρvoζ, meaning frost or icy cold) is the study of the behavior of matter at very cold temperatures. The purpose of this course is to provide trainees with an introduction to cryogen use, the hazards and potential accidents related to cryogen systems, cryogen safety components, and the requirements that govern the design and use of cryogen systems at Los Alamos National Laboratory (LANL). The knowledge you gain will help you keep your workplace safe for yourself and your coworkers.

Long-term cryogenic space storage system

NASA Technical Reports Server (NTRS)

Hopkins, R. A.; Chronic, W. L.

1973-01-01

Discussion of the design, fabrication and testing of a 225-cu ft spherical cryogenic storage system for long-term subcritical applications under zero-g conditions in storing subcritical cryogens for space vehicle propulsion systems. The insulation system design, the analytical methods used, and the correlation between the performance test results and analytical predictions are described. The best available multilayer insulation materials and state-of-the-art thermal protection concepts were applied in the design, providing a boiloff rate of 0.152 lb/hr, or 0.032% per day, and an overall heat flux of 0.066 Btu/sq ft hr based on a 200 sq ft surface area. A six to eighteen month cryogenic storage is provided by this system for space applications.

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.

Design and performance evaluation of a cryogenic condenser for an in-pile experiment

NASA Technical Reports Server (NTRS)

Graham, R. W.; Crum, R. J.; Hsu, Y.

1972-01-01

An apparatus was designed to enable in-pile irradiation of materials in liquid hydrogen at cryogenic temperatures. One of the principal components of this apparatus was a horizontal tube condenser. The performance of the condenser was evaluated by running a liquid-nitrogen prototype of the apparatus at heat loads comparable to or greater than those expected during the irradiation. The test showed that the condenser was capable of handling the design heat load and that the design procedure was sound.

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.

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.

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.

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.

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

NASA Technical Reports Server (NTRS)

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

1998-01-01

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

Design of Si0.5Ge0.5 based tunnel field effect transistor and its performance evaluation

NASA Astrophysics Data System (ADS)

Singh, Gurmeet; Amin, S. Intekhab; Anand, Sunny; Sarin, R. K.

2016-04-01

In this work, the performance comparison of two heterojunction PIN TFETs having Si channel and Si0.5Ge0.5 source with high-k (SiGe DGTFET HK) and hetero-gate dielectric (SiGe DGTFET HG) respectively with those of two homojunction Si based PIN (DGTFET HK and DGTFET HG) TFETs is performed. Similarly, by employing the technique of pocketing at source junction in above four PIN TFETs, the performances of resultant four PNPN TFETs (SiGe PNPN DGTFET HK, SiGe PNPN DGTFET HG, PNPN DGTFET HK and PNPN DGTFET HG) are also compared with each other. Due to lower tunnel resistance of SiGe based heterojunction PIN and PNPN TFETs, the DC parameters such as ON current, ON-OFF current ratio, average subthreshold slope are improved significantly as compared to Si based PIN and PNPN TFETs respectively. The output characteristics of HG architectures in Si based homojunction PIN and PNPN TFETs is observed to be identical to with respective Si based HK PIN and PNPN TFET architectures. However, the output characteristics of HG architectures in SiGe based heterojunction PIN and PNPN TFETs degrade as compared to their respective SiGe based HK PIN and PNPN TFET architectures. In ON state, SiGe based HK and HG PIN and PNPN TFETs have lower gate capacitance (Cgg) as compared to their respective Si based HK and HG PIN and PNPN TFETs. Moreover, HG architecture suppresses gate to drain capacitance (Cgd) and ambipolar conduction. Transconductance (gm) and cut off frequency (fT) is also observed to be higher for SiGe based PIN and PNPN TFETs.

High performance waveguide-coupled Ge-on-Si linear mode avalanche photodiodes.

PubMed

Martinez, Nicholas J D; Derose, Christopher T; Brock, Reinhard W; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

2016-08-22

We present experimental results for a selective epitaxially grown Ge-on-Si separate absorption and charge multiplication (SACM) integrated waveguide coupled avalanche photodiode (APD) compatible with our silicon photonics platform. Epitaxially grown Ge-on-Si waveguide-coupled linear mode avalanche photodiodes with varying lateral multiplication regions and different charge implant dimensions are fabricated and their illuminated device characteristics and high-speed performance is measured. We report a record gain-bandwidth product of 432 GHz for our highest performing waveguide-coupled avalanche photodiode operating at 1510nm. Bit error rate measurements show operation with BER< 10^-12, in the range from -18.3 dBm to -12 dBm received optical power into a 50 Ω load and open eye diagrams with 13 Gbps pseudo-random data at 1550 nm.

Cryogenic Fluid Management Technologies for Advanced Green Propulsion Systems

NASA Technical Reports Server (NTRS)

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

2007-01-01

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

A high performance pMOSFET with two-step recessed SiGe-S/D structure for 32 nm node and beyond

NASA Astrophysics Data System (ADS)

Yasutake, Nobuaki; Azuma, Atsushi; Ishida, Tatsuya; Ohuchi, Kazuya; Aoki, Nobutoshi; Kusunoki, Naoki; Mori, Shinji; Mizushima, Ichiro; Morooka, Tetsu; Kawanaka, Shigeru; Toyoshima, Yoshiaki

2007-11-01

A novel SiGe-S/D structure for high performance pMOSFET called two-step recessed SiGe-source/drain (S/D) is developed with careful optimization of recessed SiGe-S/D structure. With this method, hole mobility, short channel effect and S/D resistance in pMOSFET are improved compared with conventional recessed SiGe-S/D structure. To enhance device performance such as drain current drivability, SiGe region has to be closer to channel region. Then, conventional deep SiGe-S/D region with carefully optimized shallow SiGe SDE region showed additional device performance improvement without SCE degradation. As a result, high performance 24 nm gate length pMOSFET was demonstrated with drive current of 451 μA/μm at ∣ Vdd∣ of 0.9 V and Ioff of 100 nA/μm (552 μA/μm at ∣ Vdd∣ of 1.0 V). Furthermore, by combining with Vdd scaling, we indicate the extendability of two-step recessed SiGe-S/D structure down to 15 nm node generation.

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.

Design and demonstrate the performance of cryogenic components representative of space vehicles: Start basket liquid acquisition device performance analysis

NASA Technical Reports Server (NTRS)

1987-01-01

The objective was to design, fabricate and test an integrated cryogenic test article incorporating both fluid and thermal propellant management subsystems. A 2.2 m (87 in) diameter aluminum test tank was outfitted with multilayer insulation, helium purge system, low-conductive tank supports, thermodynamic vent system, liquid acquisition device and immersed outflow pump. Tests and analysis performed on the start basket liquid acquisition device and studies of the liquid retention characteristics of fine mesh screens are discussed.

Eddy Current Damper for Cryogenic Applications

NASA Astrophysics Data System (ADS)

Starin, Scott; Crosno, Fred

2002-09-01

This presentation considers the following topics: the need for cryogenic energy absorption, high speed damper characteristics, gearbox characteristics, composite assembly characteristics, performance tests, simulation models.

Cryogenic Moisture Uptake in Foam Insulation for Space Launch Vehicles

NASA Technical Reports Server (NTRS)

Fesmire, James E.; ScholtensCoffman, Brekke E.; Sass, Jared P.; Williams, Martha K.; Smith, Trent M.; Meneghelli, Barrry J.

2008-01-01

Rigid polyurethane foams and rigid polyisocyanurate foams (spray-on foam insulation), like those flown on Shuttle, Delta IV, and will be flown on Ares-I and Ares-V, can gain an extraordinary amount of water when under cryogenic conditions for several hours. These foams, when exposed for eight hours to launch pad environments on one side and cryogenic temperature on the other, increase their weight from 35 to 80 percent depending on the duration of weathering or aging. This effect translates into several thousand pounds of additional weight for space vehicles at lift-off. A new cryogenic moisture uptake apparatus was designed to determine the amount of water/ice taken into the specimen under actual-use propellant loading conditions. This experimental study included the measurement of the amount of moisture uptake within different foam materials. Results of testing using both aged specimens and weathered specimens are presented. To better understand cryogenic foam insulation performance, cryogenic moisture testing is shown to be essential. The implications for future launch vehicle thermal protection system design and flight performance are discussed.

Pulse shape discrimination performance of inverted coaxial Ge detectors

NASA Astrophysics Data System (ADS)

Domula, A.; Hult, M.; Kermaïdic, Y.; Marissens, G.; Schwingenheuer, B.; Wester, T.; Zuber, K.

2018-05-01

We report on the characterization of two inverted coaxial Ge detectors in the context of being employed in future 76Ge neutrinoless double beta (0 νββ) decay experiments. It is an advantage that such detectors can be produced with bigger Ge mass as compared to the planar Broad Energy Ge (BEGe) or p-type Point Contact (PPC) detectors that are currently used in the GERDA and MAJORANA DEMONSTRATOR 0 νββ decay experiments respectively. This will result in a lower background for the search of 0 νββ decay due to a reduction of detector surface to volume ratio, cables, electronics and holders which are dominating nearby radioactive sources. The measured resolution near the 76Ge Q-value at 2039 keV is 2.3 keV FWHM and their pulse-shape discrimination of background events are similar to BEGe and PPC detectors. It is concluded that this type of Ge-detector is suitable for usage in 76Ge 0 νββ decay experiments.

Reusable cryogenic foam insulation for advanced aerospace vehicles

NASA Technical Reports Server (NTRS)

Mcauliffe, Patrick S.; Taylor, Allan H.; Sparks, Larry L.; Dube, William P.

1991-01-01

Future high-speed aircraft and aerospace vehicles using cryogenic propellants will require an advanced reusable insulation system for the propellant tank structure. This cryogenic insulation system must be lightweight, structurally and thermally efficient, and capable of multiple reuse without cracking or degraded performance. This paper presents recent progress in the development of a reusable cryogenic foam insulation system having a maximum service temperature of 400 F. The system consists of preshaped, precut blocks of rigid polymethacrylimide foam insulation, wrapped with a high-temperature Kapton and aluminum foil vapor barrier which is adhesively bonded to the propellant tank wall.

Thermal Performance of a Cryogenic Fluid Management Cubesat Mission

NASA Technical Reports Server (NTRS)

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

2013-01-01

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

Mesoporous Hollow Ge Microspheres Prepared via Molten-Salt Metallothermic Reaction for High-Performance Li-Storage Anode.

PubMed

Lin, Ning; Li, Tieqiang; Han, Ying; Zhang, Qianliang; Xu, Tianjun; Qian, Yitai

2018-03-14

Generally, Ge-based anodes are prepared by metallothermic reduction of GeO 2 with Mg at 650 °C. Herein, a molten-salt system is developed a low-temperature metallothermic reduction of GeO 2 to prepare nanostructured Ge based anode materials. Typically, mesoporous hollow Ge microspheres are prepared by reduction of GeO 2 with metallic Mg in molten ZnCl 2 (mp 292) at 350 °C. Monodispersed Ge particles are synthesized through reduction of GeO 2 with Mg in molten AlCl 3 (mp 192 °C) at 250 °C. The meso-porous Ge anode delivers the reversible capacity of 1291 mA h g -1 at 0.2 C after 150 cycles with a retention of 97.3%, 1217 mA h g -1 at 0.8 C after 400 cycles with a retention of 91.9%, and superior rate capability with a capacity of 673 mA h g -1 even at 10 C. Then, the reaction mechanism and full-cell performance of as-prepared Ge anodes are studied systemically.

Thales Cryogenics rotary cryocoolers for HOT applications

NASA Astrophysics Data System (ADS)

Martin, Jean-Yves; Cauquil, Jean-Marc; Benschop, Tonny; Freche, Sébastien

2012-06-01

Thales Cryogenics has an extensive background in delivering reliable linear and rotary coolers for military, civil and space programs. Recent work carried out at detector level enable to consider a higher operation temperature for the cooled detectors. This has a direct impact on the cooling power required to the cryocooler. In continuation of the work presented last year, Thales cryogenics has studied the operation and optimization of the rotary cryocoolers at high cold regulation temperature. In this paper, the performances of the Thales Cryogenics rotary cryocoolers at elevated cold regulation temperature will be presented. From these results, some trade-offs can be made to combine correct operation of the cryocooler on all the ambient operational range and maximum efficiency of the cryocooler. These trade-offs and the impact on MTTF of elevated cold regulation temperature will be presented and discussed. In correlation with the increase of the cold operation temperature, the cryocooler input power is significantly decreased. As a consequence, the cooler drive electronics own consumption becomes relatively important and must be reduced in order to minimize global input power to the cooling function (cryocooler and cooler drive electronics). Thales Cryogenics has developed a new drive electronics optimized for low input power requirements. In parallel, improvements on RM1 and RM2 cryocoolers have been defined and implemented. The main impacts on performances of these new designs will be presented. Thales cryogenics is now able to propose an efficient cooling function for application requiring a high cold regulation temperature including a range of tuned rotary coolers.

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.

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;

High performance waveguide-coupled Ge-on-Si linear mode avalanche photodiodes

DOE PAGES

Martinez, Nicholas J. D.; Derose, Christopher T.; Brock, Reinhard W.; ...

2016-08-09

Here, we present experimental results for a selective epitaxially grown Ge-on-Si separate absorption and charge multiplication (SACM) integrated waveguide coupled avalanche photodiode (APD) compatible with our silicon photonics platform. Epitaxially grown Ge-on-Si waveguide-coupled linear mode avalanche photodiodes with varying lateral multiplication regions and different charge implant dimensions are fabricated and their illuminated device characteristics and high-speed performance is measured. We report a record gain-bandwidth product of 432 GHz for our highest performing waveguide-coupled avalanche photodiode operating at 1510nm. Bit error rate measurements show operation with BER< 10 –12, in the range from –18.3 dBm to –12 dBm received optical powermore » into a 50 Ω load and open eye diagrams with 13 Gbps pseudo-random data at 1550 nm.« less

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

NASA Astrophysics Data System (ADS)

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

2016-07-01

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

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

NASA Technical Reports Server (NTRS)

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

2016-01-01

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

Computing Thermal Effects of Cavitation in Cryogenic Liquids

NASA Technical Reports Server (NTRS)

Hosangadi, Ashvin; Ahuja, Vineet; Dash, Sanford M.

2005-01-01

A computer program implements a numerical model of thermal effects of cavitation in cryogenic fluids. The model and program were developed for use in designing and predicting the performances of turbopumps for cryogenic fluids. Prior numerical models used for this purpose do not account for either the variability of properties of cryogenic fluids or the thermal effects (especially, evaporative cooling) involved in cavitation. It is important to account for both because in a cryogenic fluid, the thermal effects of cavitation are substantial, and the cavitation characteristics are altered by coupling between the variable fluid properties and the phase changes involved in cavitation. The present model accounts for both thermal effects and variability of properties by incorporating a generalized representation of the properties of cryogenic fluids into a generalized compressible-fluid formulation for a cavitating pump. The model has been extensively validated for liquid nitrogen and liquid hydrogen. Using the available data on the properties of these fluids, the model has been shown to predict accurate temperature-depression values.

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.

Cryogenic hydrogen-induced air-liquefaction technologies

NASA Technical Reports Server (NTRS)

Escher, William J. D.

1990-01-01

Extensive use of a special advanced airbreathing propulsion archives data base, as well as direct contacts with individuals who were active in the field in previous years, a technical assessment of cryogenic hydrogen induced air liquefaction, as a prospective onboard aerospace vehicle process, was performed and documented in 1986. The resulting assessment report is summarized. Technical findings relating the status of air liquefaction technology are presented both as a singular technical area, and also as that of a cluster of collateral technical areas including: Compact lightweight cryogenic heat exchangers; Heat exchanger atmospheric constituents fouling alleviation; Para/ortho hydrogen shift conversion catalysts; Hydrogen turbine expanders, cryogenic air compressors and liquid air pumps; Hydrogen recycling using slush hydrogen as heat sinks; Liquid hydrogen/liquid air rocket type combustion devices; Air Collection and Enrichment System (ACES); and Technically related engine concepts.

Possible human endogenous cryogens.

PubMed

Shido, Osamu; Sugimoto, Naotoshi

2011-06-01

Anapyrexia, which is a regulated fall in core temperature, is beneficial for animals and humans when the oxygen supply is limited, e.g., hypoxic, ischemic, or histotoxic hypoxia, since at low body temperature the tissues require less oxygen due to Q(10). Besides hypoxia, anapyrexia can be induced various exogenous and endogenous substances, named cryogens. However, there are only a few reports investigating endogenous cryogens in mammals. We have experienced one patient who suffered from severe hypothermia. The patient seemed to be excessively producing endogenous peptidergic cryogenic substances the molecular weight of which may be greater than 30 kDa. In animal studies, the patient's cryogen appeared to affect metabolic functions, including thermogenic threshold temperatures, and then to produce hypothermia. Since endogenous cryogenic substances may be regarded as useful tool in human activities, e.g., during brain hypothermia therapy or staying in a space station or spaceship, further studies may be needed to identify human endogenous cryogens.

High performance Ω-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts.

PubMed

Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E

2010-10-29

Ge nanowires (NWs) about 2 µm long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH(4) as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu(3)Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga(+) implantation leading to a high performance Ω-gated Ge-NW MOSFET with saturation currents of a few microamperes.

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.

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.

Development of 100 g Si and 250 g Ge detectors for a dark matter search

NASA Astrophysics Data System (ADS)

Brink, P. L.; Cabrera, B.; Chugg, B.; Clarke, R. M.; Davies, A.; Nam, S. W.; Young, B. A.

1996-05-01

Over the last two years we have proposed and implemented a new phonon sensing scheme for Cryogenic elementary particle detectors based upon Transition Edge Sensors (TES) operated in the (negative) Electrothermal-feedback (ETF) mode, and utilizing large Al collection pads for the initial phonon absorption. We have also implemented an ionization electrode, in addition to the phonon sensors, to allow the simultaneous measurement of ionization and phonon signals in Si and Ge absorbers. Our progress to date include successfully discriminating between electron and nuclear recoils down to a threshold of 4 keV recoil energy for a 4 g Si detector. Our first 100 g Si detectors have been fabricated, and initial work on Ge detectors indicates that our phonon sensing scheme will also work on large mass Ge absorbers.

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

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

NASA Technical Reports Server (NTRS)

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

2001-01-01

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

A microwave cryogenic low-noise amplifier based on sige heterostructures

NASA Astrophysics Data System (ADS)

Ivanov, B. I.; Grajcar, M.; Novikov, I. L.; Vostretsov, A. G.; Il'ichev, E.

2016-04-01

A low-noise cryogenic amplifier for the measurement of weak microwave signals at sub-Kelvin temperatures is constructed. The amplifier has five stages based on SiGe bipolar heterostructure transistors and has a gain factor of 35 dB in the frequency band from 100 MHz to 4 GHz at an operating temperature of 800 mK. The parameters of a superconducting quantum bit measured with this amplifier in the ultralow-power mode are presented as an application example. The amplitude-frequency response of the "supercon-ducting qubit-coplanar cavity" structure is demonstrated. The ground state of the qubit is characterized in the quasi-dispersive measurement mode.

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

NASA Technical Reports Server (NTRS)

Russell, John M.

1989-01-01

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

The cryogenics design of the SuperCDMS SNOLAB experiment

NASA Astrophysics Data System (ADS)

Hollister, M. I.; Bauer, D. A.; Dhuley, R. C.; Lukens, P.; Martin, L. D.; Ruschman, M. K.; Schmitt, R. L.; Tatkowski, G. L.

2017-12-01

The Super Cryogenic Dark Matter Search (SuperCDMS) experiment is a direct detection dark matter experiment intended for deployment to the SNOLAB underground facility in Ontario, Canada. With a payload of up to 186 germanium and silicon crystal detectors operating below 15 mK, the cryogenic architecture of the experiment is complex. Further, the requirement that the cryostat presents a low radioactive background to the detectors limits the materials and techniques available for construction, and heavily influences the design of the cryogenics system. The resulting thermal architecture is a closed cycle (no liquid cryogen) system, with stages at 50 and 4 K cooled with gas and fluid circulation systems and stages at 1 K, 250 mK and 15 mK cooled by the lower temperature stages of a large, cryogen-free dilution refrigerator. This paper describes the thermal design of the experiment, including details of the cooling systems, mechanical designs and expected performance of the system under operational conditions.

PIP-II Cryogenic System and the Evolution of Superfluid Helium Cryogenic Plant Specifications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakravarty, Anindya; Rane, Tejas; Klebaner, Arkadiy

2017-01-01

PIP-II cryogenic system: Superfluid Helium Cryogenic Plant (SHCP) and Cryogenic Distribution System (CDS) connecting the SHCP and the SC Linac (25 cryomodules) PIP-II Cryogenic System Static and dynamic heat loads for the SC Linac and static load of CDS listed out Simulation study carried out to compute SHe flow requirements for each cryomodule Comparison between the flow requirements of the cryomodules for the CW and pulsed modes of operation presented From computed heat load and pressure drop values, SHCP basic specifications evolved.

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.

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.

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.

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.

New Cryogenic Optical Test Capability at Marshall Space Flight Center's Space Optics Manufacturing Technology Center

NASA Technical Reports Server (NTRS)

Kegley, Jeff; Burdine, Robert V. (Technical Monitor)

2002-01-01

A new cryogenic optical testing capability exists at Marshall Space Flight Center's Space Optics Manufacturing Technology Center (SOMTC). SOMTC has been performing optical wavefront testing at cryogenic temperatures since 1999 in the X-ray Cryogenic Test Facility's (XRCF's) large vacuum chamber. Recently the cryogenic optical testing capability has been extended to a smaller vacuum chamber. This smaller horizontal cylindrical vacuum chamber has been outfitted with a helium-cooled liner that can be connected to the facility's helium refrigeration system bringing the existing kilowatt of refrigeration capacity to bear on a 1 meter diameter x 2 meter long test envelope. Cryogenic environments to less than 20 Kelvin are now possible in only a few hours. SOMTC's existing instruments (the Instantaneous Phase-shifting Interferometer (IPI) from ADE Phase-Shift Technologies and the PhaseCam from 4D Vision Technologies) view the optic under test through a 150 mm clear aperture BK-7 window. Since activation and chamber characterization tests in September 2001, the new chamber has been used to perform a cryogenic (less than 30 Kelvin) optical test of a 22.5 cm diameter x 127 cm radius of curvature Si02 mirror, a cryogenic survival (less than 30 Kelvin) test of an adhesive, and a cryogenic cycle (less than 20 Kelvin) test of a ULE mirror. A vibration survey has also been performed on the test chamber. Chamber specifications and performance data, vibration environment data, and limited test results will be presented.

New Cryogenic Optical Test Capability at Marshall Space Flight Center's Space Optics Manufacturing Technology Center

NASA Technical Reports Server (NTRS)

Kegley, Jeff; Stahl, H. Philip (Technical Monitor)

2002-01-01

A new cryogenic optical testing capability exists at Marshall Space Flight Center's Space Optics Manufacturing Technology Center (SOMTC). SOMTC has been performing optical wavefront testing at cryogenic temperatures since 1999 in the X-ray Cryogenic Test Facility's (XRCF's) large vacuum chamber. Recently the cryogenic optical testing capability has been extended to a smaller vacuum chamber. This smaller horizontal cylindrical vacuum chamber has been outfitted with a helium-cooled liner that can be connected to the facility's helium refrigeration system bringing the existing kilowatt of refrigeration capacity to bear on a 1 meter diameter x 2 meter long test envelope. Cryogenic environments to less than 20 Kelvin are now possible in only a few hours. SOMTC's existing instruments (the Instantaneous Phase-shifting Interferometer (IPI) from ADE Phase-Shift Technologies and the PhaseCam from 4D Vision Technologies) view the optic under test through a 150 mm clear aperture BK-7 window. Since activation and chamber characterization tests in September 2001, the new chamber has been used to perform a cryogenic (less than 30 Kelvin) optical test of a 22.5 cm diameter x 127 cm radius of curvature SiO2 mirror, a cryogenic survival (less than 30 Kelvin) test of an adhesive, and a cryogenic cycle (less than 20 Kelvin) test of a ULE mirror. A vibration survey has also been performed on the test chamber. Chamber specifications and performance data, vibration environment data, and limited test results will be presented.

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.

Testing of Prototype Magnetic Suspension Cryogenic Transfer Line

NASA Astrophysics Data System (ADS)

Fesmire, J. E.; Augustynowicz, S. D.; Nagy, Z. F.; Sojourner, S. J.; Shu, Q. S.; Cheng, G.; Susta, J. T.

2006-04-01

A 6-meter prototype cryogenic transfer line with magnetic suspension was tested for its mechanical and thermal performance at the Cryogenics Test Laboratory of NASA Kennedy Space Center (KSC). A test facility with two cryogenic end-boxes was designed and commissioned for the testing. Suspension mechanisms were verified through a series of tests with liquid nitrogen. The thermal performance of the prototype was determined using the new test apparatus. The tested prototype has incorporated temperature and vacuum pressure data acquisition ports, customized interfaces to cryogenic end-boxes, and instrumentation. All tests were conducted under simulated onsite transfer line working conditions. A static (boiloff rate measurement) testing method was employed to demonstrate the gross heat leak in the tested article. The real-time temperature distribution, vacuum level, levitation distance, and mass flow rate were measured. The main purpose of this paper is to summarize the testing facility design and preparation, test procedure, and primary test results. Special arrangements (such as turning on/off mechanical support units, observing levitation gap, and setting up the flowmeter) in testing of such a magnetically levitated transfer line are also discussed. Preliminary results show that the heat leak reduction of approximately one-third to one-half is achievable through such transfer lines with a magnetic suspension system.

Performance of the JT-60SA cryogenic system under pulsed heat loads during acceptance tests

NASA Astrophysics Data System (ADS)

Hoa, C.; Bonne, F.; Roussel, P.; Lamaison, V.; Girard, S.; Fejoz, P.; Goncalves, R.; Vallet, J. C.; Legrand, J.; Fabre, Y.; Pudys, V.; Wanner, M.; Cardella, A.; Di Pietro, E.; Kamiya, K.; Natsume, K.; Ohtsu, K.; Oishi, M.; Honda, A.; Kashiwa, Y.; Kizu, K.

2017-12-01

The JT-60SA cryogenic system a superconducting tokamak currently under assembly at Naka, Japan. After one year of commissioning, the acceptance tests were successfully completed in October 2016 in close collaboration with Air Liquide Advanced Technologies (ALaT), the French atomic and alternative energies commission (CEA), Fusion for Energy (F4E) and the Quantum Radiological Science and Technology (QST). The cryogenic system has several cryogenic users at various temperatures: the superconducting magnets at 4.4 K, the current leads at 50 K, the thermal shields at 80 K and the divertor cryo-pumps at 3.7 K. The cryogenic system has an equivalent refrigeration power of about 9.5 kW at 4.5 K, with peak loads caused by the nuclear heating, the eddy currents in the structures and the AC losses in the magnets during cyclic plasma operation. The main results of the acceptance tests will be reported, with emphasis on the management of the challenging pulsed load operation using a liquid helium volume of 7 m3 as a thermal damper.

Sources of Cryogenic Data and Information

NASA Astrophysics Data System (ADS)

Mohling, R. A.; Hufferd, W. L.; Marquardt, E. D.

It is commonly known that cryogenic data, technology, and information are applied across many military, National Aeronautics and Space Administration (NASA), and civilian product lines. Before 1950, however, there was no centralized US source of cryogenic technology data. The Cryogenic Data Center of the National Bureau of Standards (NBS) maintained a database of cryogenic technical documents that served the national need well from the mid 1950s to the early 1980s. The database, maintained on a mainframe computer, was a highly specific bibliography of cryogenic literature and thermophysical properties that covered over 100 years of data. In 1983, however, the Cryogenic Data Center was discontinued when NBS's mission and scope were redefined. In 1998, NASA contracted with the Chemical Propulsion Information Agency (CPIA) and Technology Applications, Inc. (TAI) to reconstitute and update Cryogenic Data Center information and establish a self-sufficient entity to provide technical services for the cryogenic community. The Cryogenic Information Center (CIC) provided this service until 2004, when it was discontinued due to a lack of market interest. The CIC technical assets were distributed to NASA Marshall Space Flight Center and the National Institute of Standards and Technology. Plans are under way in 2006 for CPIA to launch an e-commerce cryogenic website to offer bibliography data with capability to download cryogenic documents.

Development of COPVS for High pressure, In-Space, Cryogenic Fuel Storage

NASA Technical Reports Server (NTRS)

DeLay, Tom; Schneider, Judy; Dyess, Mark; Hastings, Chad; Noorda, Ryan; Noorda, Jared; Patterson, James

2008-01-01

Polymeric composite overwrapped pressure vessels (COPVs) provide an attractive material system to support developing commercial launch business and alternate fuel ventures. However to be able to design with these materials, the mechanical behavior of the materials must be understood with regards to processing, performance, damage tolerance, and environment. For the storage of cryogenic propellants, it is important to evaluate the materials performance and impact damage resistance at cryogenic temperatures in order to minimize weight and to ensure safety and reliability. To evaluate the ultimate performance, various polymeric COPV's have been statically burst tested at cryogenic conditions before and after exposure to irradiation. Materials selected for these COPVs were based on the measured mechanical properties of candidate resin systems and fibers that were also tested at cryogenic conditions before and after exposure to irradiation. The correlation of COPV burst pressures with the constituent material properties has proven to be a valuable screening method for selection of suitable candidate materials with resistance to material degradation due to exposure to temperature and radiation.

Improved Cryogenic Optical Test Capability at Marshall Space Flight Center's X-ray Cryogenic Test Facility

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey; Haight, Harlan; Hogue, William; Carpenter, Jay; Siler, Richard; Wright, Ernie; Eng, Ron; Baker, Mark; McCracken, Jeff

2005-01-01

Marshall Space Flight Center's X-ray & Cryogenic Test Facility (XRCF) has been performing optical wavefront testing and thermal structural deformation testing at subliquid nitrogen cryogenic temperatures since 1999. Recent modifications have been made to the facility in support of the James Webb Space Telescope (JWST) program. The test article envelope and the chamber's refrigeration capacity have both been increased. A new larger helium-cooled enclosure has been added to the existing enclosure increasing both the cross-sectional area and the length. This new enclosure is capable of supporting six JWST Primary Mirror Segment Assemblies. A second helium refrigeration system has been installed essentially doubling the cooling capacity available at the facility. Modifications have also been made to the optical instrumentation area. Improved access is now available for both the installation and operation of optical instrumentation outside the vacuum chamber. Chamber configuration, specifications, and performance data will be presented.

(abstract) Simple Spreadsheet Thermal Models for Cryogenic Applications

NASA Technical Reports Server (NTRS)

Nash, A. E.

1994-01-01

Self consistent circuit analog thermal models, that can be run in commercial spreadsheet programs on personal computers, have been created to calculate the cooldown and steady state performance of cryogen cooled Dewars. The models include temperature dependent conduction and radiation effects. The outputs of the models provide temperature distribution and Dewar performance information. These models have been used to analyze the Cryogenic Telescope Test Facility (CTTF). The facility will be on line in early 1995 for its first user, the Infrared Telescope Technology Testbed (ITTT), for the Space Infrared Telescope Facility (SIRTF) at JPL. The model algorithm as well as a comparison of the model predictions and actual performance of this facility will be presented.

Outsourcing strategy and tendering methodology for the operation and maintenance of CERN’s cryogenic facilities

NASA Astrophysics Data System (ADS)

Serio, L.; Bremer, J.; Claudet, S.; Delikaris, D.; Ferlin, G.; Ferrand, F.; Pezzetti, M.; Pirotte, O.

2017-12-01

CERN operates and maintains the world largest cryogenic infrastructure ranging from ageing but well maintained installations feeding detectors, test facilities and general services, to the state-of-the-art cryogenic system serving the flagship LHC machine complex. A study was conducted and a methodology proposed to outsource to industry the operation and maintenance of the whole cryogenic infrastructure. The cryogenic installations coupled to non LHC-detectors, test facilities and general services infrastructure have been fully outsourced for operation and maintenance on the basis of performance obligations. The contractor is responsible for the operational performance of the installations based on a yearly operation schedule provided by CERN. The maintenance of the cryogenic system serving the LHC machine and its detectors has been outsourced on the basis of tasks oriented obligations, monitored by key performance indicators. CERN operation team, with the support of the contractor operation team, remains responsible for the operational strategy and performances. We report the analysis, strategy, definition of the requirements and technical specifications as well as the achieved technical and economic performances after one year of operation.

Development of Advanced Tools for Cryogenic Integration

NASA Astrophysics Data System (ADS)

Bugby, D. C.; Marland, B. C.; Stouffer, C. J.; Kroliczek, E. J.

2004-06-01

This paper describes four advanced devices (or tools) that were developed to help solve problems in cryogenic integration. The four devices are: (1) an across-gimbal nitrogen cryogenic loop heat pipe (CLHP); (2) a miniaturized neon CLHP; (3) a differential thermal expansion (DTE) cryogenic thermal switch (CTSW); and (4) a dual-volume nitrogen cryogenic thermal storage unit (CTSU). The across-gimbal CLHP provides a low torque, high conductance solution for gimbaled cryogenic systems wishing to position their cryocoolers off-gimbal. The miniaturized CLHP combines thermal transport, flexibility, and thermal switching (at 35 K) into one device that can be directly mounted to both the cooler cold head and the cooled component. The DTE-CTSW, designed and successfully tested in a previous program using a stainless steel tube and beryllium (Be) end-pieces, was redesigned with a polymer rod and high-purity aluminum (Al) end-pieces to improve performance and manufacturability while still providing a miniaturized design. Lastly, the CTSU was designed with a 6063 Al heat exchanger and integrally welded, segmented, high purity Al thermal straps for direct attachment to both a cooler cold head and a Be component whose peak heat load exceeds its average load by 2.5 times. For each device, the paper will describe its development objective, operating principles, heritage, requirements, design, test data and lessons learned.

Cryogenic Insulation System

NASA Technical Reports Server (NTRS)

Davis, Randall C. (Inventor); Taylor, Allan H. (Inventor); Jackson, L. Robert (Inventor); Mcauliffe, Patrick S. (Inventor)

1988-01-01

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system.

CryoPAF4: a cryogenic phased array feed design

NASA Astrophysics Data System (ADS)

Locke, Lisa; Garcia, Dominic; Halman, Mark; Henke, Doug; Hovey, Gary; Jiang, Nianhua; Knee, Lewis; Lacy, Gordon; Loop, David; Rupen, Michael; Veidt, Bruce; Wierzbicki, Ramunas

2016-07-01

Phased array feed (PAF) receivers used on radio astronomy telescopes offer the promise of increased fields of view while maintaining the superlative performance attained with traditional single pixel feeds (SPFs). However, the much higher noise temperatures of room temperature PAFs compared to cryogenically-cooled SPFs have prevented their general adoption. Here we describe a conceptual design for a cryogenically cooled 2.8 - 5.18 GHz dual linear polarization PAF with estimated receiver temperature of 11 K. The cryogenic PAF receiver will comprise a 140 element Vivaldi antenna array and low-noise amplifiers housed in a 480 mm diameter cylindrical dewar covered with a RF transparent radome. A broadband two-section coaxial feed is integrated within each metal antenna element to withstand the cryogenic environment and to provide a 50 ohm impedance for connection to the rest of the receiver. The planned digital beamformer performs digitization, frequency band selection, beam forming and array covariance matrix calibration. Coupling to a 15 m offset Gregorian dual-reflector telescope, cryoPAF4 can expect to form 18 overlapping beams increasing the field of view by a factor of 8x compared to a single pixel receiver of equal system temperature.

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

NASA Astrophysics Data System (ADS)

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

2015-03-01

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

Thermohydrodynamic Analysis of Cryogenic Liquid Turbulent Flow Fluid Film Bearings

NASA Technical Reports Server (NTRS)

San Andres, Luis

1996-01-01

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

Study of Cryogenic Complex Plasma

DTIC Science & Technology

2008-10-27

nitrogen or liquid helium) and dust particles are introduced in the plasma. In YD-2, a cryogenic plasma is produced in the vapor of liquid helium above the...cryogenic liquid ( liquid nitrogen or liquid helium) and dust particles are introduced in the plasma. In YD-2, a cryogenic plasma is produced in the vapor...cryogenic liquid ( liquid nitrogen or liquid helium) in the Dewar bottle produces a stable plasma. We have been successful in producing a plasma (1

Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.

1985-01-01

The Cryogenic Fluid Management Facility is a reusable test bed which is designed to be carried within the Shuttle cargo bay to investigate the systems and technologies associated with the efficient management of cryogens in space. Cryogenic fluid management consists of the systems and technologies for: (1) liquid storage and supply, including capillary acquisition/expulsion systems which provide single-phase liquid to the user system, (2) both passive and active thermal control systems, and (3) fluid transfer/resupply systems, including transfer lines and receiver tanks. The facility contains a storage and supply tank, a transfer line and a receiver tank, configured to provide low-g verification of fluid and thermal models of cryogenic storage and transfer processes. The facility will provide design data and criteria for future subcritical cryogenic storage and transfer system applications, such as Space Station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, and ground-based and space-based orbit transfer vehicles (OTV).

Cryogenic Fluid Management Facility

NASA Technical Reports Server (NTRS)

Eberhardt, R. N.; Bailey, W. J.; Symons, E. P.; Kroeger, E. W.

1984-01-01

The Cryogenic Fluid Management Facility (CFMF) is a reusable test bed which is designed to be carried into space in the Shuttle cargo bay to investigate systems and technologies required to efficiently and effectively manage cryogens in space. The facility hardware is configured to provide low-g verification of fluid and thermal models of cryogenic storage, transfer concepts and processes. Significant design data and criteria for future subcritical cryogenic storage and transfer systems will be obtained. Future applications include space-based and ground-based orbit transfer vehicles (OTV), space station life support, attitude control, power and fuel depot supply, resupply tankers, external tank (ET) propellant scavenging, space-based weapon systems and space-based orbit maneuvering vehicles (OMV). This paper describes the facility and discusses the cryogenic fluid management technology to be investigated. A brief discussion of the integration issues involved in loading and transporting liquid hydrogen within the Shuttle cargo bay is also included.

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.

Developments in advanced and energy saving thermal isolations for cryogenic applications

NASA Astrophysics Data System (ADS)

Shu, Q. S.; Demko, J. A.; Fesmire, J. E.

2015-12-01

The cooling power consumption in large scale superconducting systems is huge and cryogenic devices used in space applications often require an extremely long cryogen holding time. To economically maintain the device at its operating temperature and minimize the refrigeration losses, high performance of thermal isolation is essential. The radiation from warm surrounding surfaces and conducting heat leaks through supports and penetrations are the dominant heat loads to the cold mass under vacuum condition. The advanced developments in various cryogenic applications to successfully reduce the heat loads through radiation and conduction are briefly and systematically discussed and evaluated in this review paper. These include: (1) thermal Insulation for different applications (foams, perlites, glass bubbles, aerogel and MLI), (2) sophisticated low-heat-leak support (cryogenic tension straps, trolley bars and posts with dedicated thermal intercepts), and (3) novel cryogenic heat switches.

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.

Direct-Drive DT Cryogenic Implosion Performance with a Fill Tube

NASA Astrophysics Data System (ADS)

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

2017-10-01

The effects of a fill tube on the performance of direct-drive DT cryogenic implosions on the 60-beam, 30-kJ, 351-nm OMEGA laser are presented. The calculated adiabat, convergence ratio, and in-flight-aspect ratio quantities were 4, 17, and 23, respectively. Changes to the measured neutron yield, areal density, and ion temperature caused by the fill tube were found to be within experimental uncertainties. Gated x-ray images recorded during the acceleration phase at photon energies down to 1 keV show evidence of the fill tube perturbing the imploding shell and causing a region of enhanced emission from the hot spot, while gated x-ray images of the hot spot in the 4- to 8-keV photon energy range show no effect from the fill tube. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

Nanotribological behavior of deep cryogenically treated martensitic stainless steel

PubMed Central

Bakoglidis, Konstantinos D; Tuckart, Walter R; Broitman, Esteban

2017-01-01

Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic–plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally. PMID:28904837

Nanotribological behavior of deep cryogenically treated martensitic stainless steel.

PubMed

Prieto, Germán; Bakoglidis, Konstantinos D; Tuckart, Walter R; Broitman, Esteban

2017-01-01

Cryogenic treatments are increasingly used to improve the wear resistance of various steel alloys by means of transformation of retained austenite, deformation of virgin martensite and carbide refinement. In this work the nanotribological behavior and mechanical properties at the nano-scale of cryogenically and conventionally treated AISI 420 martensitic stainless steel were evaluated. Conventionally treated specimens were subjected to quenching and annealing, while the deep cryogenically treated samples were quenched, soaked in liquid nitrogen for 2 h and annealed. The elastic-plastic parameters of the materials were assessed by nanoindentation tests under displacement control, while the friction behavior and wear rate were evaluated by a nanoscratch testing methodology that it is used for the first time in steels. It was found that cryogenic treatments increased both hardness and elastic limit of a low-carbon martensitic stainless steel, while its tribological performance was enhanced marginally.

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

NASA Astrophysics Data System (ADS)

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

2016-10-01

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

Introduction of performance boosters like Ge as channel material for the future of CMOS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Samia, Slimani, E-mail: slimani.samia@gmail.com; Laboratoire de Modélisation et Méthodes de calcul LMMC,20002 Saida; Bouaza, Djellouli, E-mail: djelbou@hotmail.fr

High mobility materials are being considered to replace Si in the channel to achieve higher drive currents and switching speeds. Ge is one of new attractive channel materials that require CMOS scaling For future technology nodes and future high performance P-MOSFETS, we have studied a nanoscale SOI DG MOSFETs using quantum simulation approach on DG MOSFETs within the variation of Ge channel concentration and in the presence of source and drain doping by replacing Silicon in the channel by Ge using various dielectric constant. The use of high mobility channel (like Ge) to maximize the MOSFET IDsat and simultaneously circumventmore » the poor electrostatic control to suppress short-channel effects and enhance source injection velocity. The leakage current (I{sub off}) can be controlled by different gates oxide thickness more ever the required threshold voltage (V{sub TH}) can be achieved by keeping gate work function and altering the doping channel.« less

POLOCAM: a millimeter wavelength cryogenic polarimeter prototype for MUSIC-POL

NASA Astrophysics Data System (ADS)

Laurent, Glenn T.; Vaillancourt, John E.; Savini, Giorgio; Ade, Peter A. R.; Beland, Stephane; Glenn, Jason; Hollister, Matthew I.; Maloney, Philip R.; Sayers, Jack

2012-09-01

As a proof-of-concept, we have constructed and tested a cryogenic polarimeter in the laboratory as a prototype for the MUSIC instrument (Multiwavelength Sub/millimeter Kinetic Inductance Camera). The POLOCAM instrument consists of a rotating cryogenic polarization modulator (sapphire half-waveplate) and polarization analyzer (lithographed copper polarizers deposited on a thin film) placed into the optical path at the Lyot stop (4K cold pupil stop) in a cryogenic dewar. We present an overview of the project, design and performance results of the POLOCAM instrument (including polarization efficiencies and instrumental polarization), as well as future application to the MUSIC-POL instrument.

Development of aerodynamic foil journal bearings for a high speed cryogenic turboexpander

NASA Astrophysics Data System (ADS)

Xiong, L.-Y.; Wu, G.; Hou, Y.; Liu, L.-Q.; Ling, M.-F.; Chen, C.-Z.

The research presented in this paper is aimed at the development of aerodynamic foil journal bearings applying to a small high speed cryogenic turboexpander. A small high speed cryogenic turboexpander is designed. Attention has been paid to the study of the effect of foil stiffness on the vibration performance of bearings. From rotation tests, it is clear that, with the proper choice of foil stiffness, the foil bearing presented here can possess sufficiently high stability. The maximum rotational speed obtained is greater than 230 000 rpm. Therefore, owing to its simplicity and high performance, this type of foil journal bearing can hopefully be applied to a small high speed cryogenic turboexpander.

Analysis and Design of Cryogenic Pressure Vessels for Automotive Hydrogen Storage

NASA Astrophysics Data System (ADS)

Espinosa-Loza, Francisco Javier

Cryogenic pressure vessels maximize hydrogen storage density by combining the high pressure (350-700 bar) typical of today's composite pressure vessels with the cryogenic temperature (as low as 25 K) typical of low pressure liquid hydrogen vessels. Cryogenic pressure vessels comprise a high-pressure inner vessel made of carbon fiber-coated metal (similar to those used for storage of compressed gas), a vacuum space filled with numerous sheets of highly reflective metalized plastic (for high performance thermal insulation), and a metallic outer jacket. High density of hydrogen storage is key to practical hydrogen-fueled transportation by enabling (1) long-range (500+ km) transportation with high capacity vessels that fit within available spaces in the vehicle, and (2) reduced cost per kilogram of hydrogen stored through reduced need for expensive structural material (carbon fiber composite) necessary to make the vessel. Low temperature of storage also leads to reduced expansion energy (by an order of magnitude or more vs. ambient temperature compressed gas storage), potentially providing important safety advantages. All this is accomplished while simultaneously avoiding fuel venting typical of cryogenic vessels for all practical use scenarios. This dissertation describes the work necessary for developing and demonstrating successive generations of cryogenic pressure vessels demonstrated at Lawrence Livermore National Laboratory. The work included (1) conceptual design, (2) detailed system design (3) structural analysis of cryogenic pressure vessels, (4) thermal analysis of heat transfer through cryogenic supports and vacuum multilayer insulation, and (5) experimental demonstration. Aside from succeeding in demonstrating a hydrogen storage approach that has established all the world records for hydrogen storage on vehicles (longest driving range, maximum hydrogen storage density, and maximum containment of cryogenic hydrogen without venting), the work also

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

Thermodynamic Analyses of the LCLS-II Cryogenic Distribution System

DOE PAGES

Dalesandro, Andrew; Kaluzny, Joshua; Klebaner, Arkadiy

2016-12-29

The Linac Coherent Light Source (LCLS) at Stanford Linear Accelerator Center (SLAC) is in the process of being upgraded to a superconducting radio frequency (SRF) accelerator and renamed LCLS-II. This upgrade requires thirty-five 1.3 GHz SRF cryomodules (CM) and two 3.9 GHz CM. A cryogenic distribution system (CDS) is in development by Fermi National Accelerator Laboratory to interconnect the CM Linac with the cryogenic plant (CP). The CDS design utilizes cryogenic helium to support the CM operations with a high temperature thermal shield around 55 K, a low temperature thermal intercepts around 5 K, and a SRF cavity liquid heliummore » supply and sub-atmospheric vapor return both around 2 K. Additionally the design must accommodate a Linac consisting of two parallel cryogenic strings, supported by two independent CP utilizing CDS components such as distribution boxes, transfer lines, feed caps and endcaps. In this paper, we describe the overall layout of the cryogenic distribution system and the major thermodynamic factors which influence the CDS design including heat loads, pressure drops, temperature profiles, and pressure relieving requirements. In addition the paper describes how the models are created to perform the analyses.« less

Recent Advances and Applications in Cryogenic Propellant Densification Technology

NASA Technical Reports Server (NTRS)

Tomsik, Thomas M.

2000-01-01

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

Proceedings of the 26th International Cryogenic Engineering Conference - International Cryogenic Material Conference 2016

NASA Astrophysics Data System (ADS)

Datta, T. S.; Sharma, R. G.; Kar, S.

2017-02-01

Session There were 6 plenary talks delivered by the eminent scientist/ technologists. The topics on which these talks were delivered were Cryogenics for Indian Space Programme, The Cold Chain, Super-fluid Cooling Technology, Review on Superconducting Materials in China, Review on Cryogenics and Superconductivity for present day MRI and finally the Mendelssohn Award lecture on the 50 years of Cryogenics and Superconductivity for High Energy Physics. Other than the plenary talks, there were 102 oral presentations covered in 18 technical sessions, out of which 21 were Invited Talks. Each session was dedicated to a specific topic like Large Scale Cryogenics, Cryogenics for Accelerators, Fusion and Space, Cryocoolers, Heat Transfer, Cryogenic Instrumentation, Superconducting Materials, Superconducting Magnets & Cavities, Power Applications, LNG & Safety etc. In addition to oral presentations there were three poster sessions spread over three days and a total of 250 posters were displayed. 4. Award Session There was a dedicated session on Award Ceremony. Dr Haishan Cao, post doctoral researcher at the University of Twente, The Netherlands received the 2016 Klipping Award for his work on Micro-machined Joule-Thomson coolers. The ICMC Cryogenic Material Awardee for Excellence (2016) was Prof. Kazumasa Iida, Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University. Japan. The paper published in ” Cryogenics 72 (2015), p 111-121 by J. Bartlett, G. Hardy, and I.D. Hepburn, titled “Performance of a fast response miniature Adiabatic Demagnetization Refrigerator using a single crystal tungsten magneto resistive heat switch” was selected for the best paper award. The prestigious 2016 Mendelssohn Award was given to Dr. Philippe Lebrun of CERN, Geneva, Switzerland for his life-long contribution to Cryogenics and Superconductivity for accelerator programme. Each awardees was also presented with a complimentary book from Springer Nature through

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.

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.

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.

Thermal Design and Analysis for the Cryogenic MIDAS Experiment

NASA Technical Reports Server (NTRS)

Amundsen, Ruth McElroy

1997-01-01

The Materials In Devices As Superconductors (MIDAS) spaceflight experiment is a NASA payload which launched in September 1996 on the Shuttle, and was transferred to the Mir Space Station for several months of operation. MIDAS was developed and built at NASA Langley Research Center (LaRC). The primary objective of the experiment was to determine the effects of microgravity and spaceflight on the electrical properties of high-temperature superconductive (HTS) materials. The thermal challenge on MIDAS was to maintain the superconductive specimens at or below 80 K for the entire operation of the experiment, including all ground testing and 90 days of spaceflight operation. Cooling was provided by a small tactical cryocooler. The superconductive specimens and the coldfinger of the cryocooler were mounted in a vacuum chamber, with vacuum levels maintained by an ion pump. The entire experiment was mounted for operation in a stowage locker inside Mir, with the only heat dissipation capability provided by a cooling fan exhausting to the habitable compartment. The thermal environment on Mir can potentially vary over the range 5 to 40 C; this was the range used in testing, and this wide range adds to the difficulty in managing the power dissipated from the experiment's active components. Many issues in the thermal design are discussed, including: thermal isolation methods for the cryogenic samples; design for cooling to cryogenic temperatures; cryogenic epoxy bonds; management of ambient temperature components self-heating; and fan cooling of the enclosed locker. Results of the design are also considered, including the thermal gradients across the HTS samples and cryogenic thermal strap, electronics and thermal sensor cryogenic performance, and differences between ground and flight performance. Modeling was performed in both SINDA-85 and MSC/PATRAN (with direct geometry import from the CAD design tool Pro/Engineer). Advantages of both types of models are discussed

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

NASA Astrophysics Data System (ADS)

Sam, Ashish Alex; Ghosh, Parthasarathi

2017-02-01

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

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

NASA Astrophysics Data System (ADS)

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

2013-12-01

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

Experimental study on cryogenic moisture uptake in polyurethane foam insulation material

NASA Astrophysics Data System (ADS)

Zhang, X. B.; Yao, L.; Qiu, L. M.; Gan, Z. H.; Yang, R. P.; Ma, X. J.; Liu, Z. H.

2012-12-01

Rigid foam is widely used to insulate cryogenic tanks, in particular for space launch vehicles due to its lightweight, mechanical strength and thermal-insulating performance. Up to now, little information is available on the intrusion of moisture into the material under cryogenic conditions, which will bring substantial additional weight for the space vehicles at lift-off. A cryogenic moisture uptake apparatus has been designed and fabricated to measure the amount of water uptake into the polyurethane foam. One side of the specimen is exposed to an environment with high humidity and ambient temperature, while the other with cryogenic temperature at approximately 78 K. A total of 16 specimens were tested for up to 24 h to explore the effects of the surface thermal protection layer, the foam thickness, exposed time, the butt joints, and the material density on water uptake of the foam. The results are constructive for the applications of the foam to the cryogenic insulation system in space launch vehicles.

The cryogenic wind tunnel for high Reynolds number testing. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Kilgore, R. A.

1974-01-01

Experiments performed at the NASA Langley Research Center in a cryogenic low-speed continuous-flow tunnel and in a cryogenic transonic continuous-flow pressure tunnel have demonstrated the predicted changes in Reynolds number, drive power, and fan speed with temperature, while operating with nitrogen as the test gas. The experiments have also demonstrated that cooling to cryogenic temperatures by spraying liquid nitrogen directly into the tunnel circuit is practical and that tunnel temperature can be controlled within very close limits. Whereas most types of wind tunnel could operate with advantage at cryogenic temperatures, the continuous-flow fan-driven tunnel is particularly well suited to take full advantage of operating at these temperatures. A continuous-flow fan-driven cryogenic tunnel to satisfy current requirements for test Reynolds number can be constructed and operated using existing techniques. Both capital and operating costs appear acceptable.

Use of Thermoset Composite Materials in Cryogenic Tanks

NASA Astrophysics Data System (ADS)

Diaz, V.; Cardone, T.; Ramusat, G.

2014-06-01

To improve the performances of Future Expendable Launchers, one of the key aspects to be considered is the mass optimization of the cryogenic upper stage of the launcher, where a mass saving of one Kg, is directly transferred to one more Kg of payload.This optimization is inherently linked to the use of composite materials in all the structures that conforms the upper stage of the launcher.Currently, most of the upper stage structures of the operational launchers, like Ariane 5, are made in composite materials, with the exception of the cryogenic (LH2 and LOX) tanks which remain metallic.So, from a structural point of view, the next qualitative step in the development of new expendable launcher, would be the manufacturing of the upper stage cryogenic tanks in composite materials.To reach this objective important concerns mainly related to the potential for leaks and the compatibility with the LOX need to be resolved.In the frame of the FLPP (Future Launcher Preparatory Program) funded by ESA, an activity related to the use of thermoset composite material in the cryogenic tanks has been included.This paper presents a summary of the performed work which includes:* The selection and characterization of the most suitable candidate materials for the considered application* The design and analysis of a subscale demonstrator representative of the LH2 compartment* The design, manufacturing and testing of some test articles representatives of the selected design solutions* The manufacturing and testing of the selected subscale demonstrator.

Testing the equipment for the cryogenic optical test of the James Webb Space Telescope

NASA Astrophysics Data System (ADS)

Whitman, Tony L.; Dziak, K. J.; Huguet, Jesse; Knight, J. Scott; Reis, Carl; Wilson, Erin

2014-08-01

After integration of the Optical Telescope Element (OTE) to the Integrated Science Instrument Module (ISIM) to become the OTIS, the JWST optics are tested at NASA's Johnson Space Center (JSC) in the cryogenic vacuum Chamber A for alignment and optical performance. Tens of trucks full of custom test equipment are being delivered to the JSC, in addition to the large pieces built at the Center, and the renovation of the chamber itself. The facility is tested for the thermal stability control for optical measurements and contamination control during temperature transitions. The support for the OTIS is also tested for thermal stability control, load tested in the cryogenic environment, and tested for isolation of the background vibration for the optical measurements. The Center of Curvature Optical Assembly (COCOA) is tested for the phasing and wavefront error (WFE) measurement of an 18 segment mirror and for cryogenic operation. A photogrammetry system is tested for metrology performance and cryogenic operation. Test mirrors for auto-collimation measurements are tested for optical performance and cryogenic operation. An assembly of optical test sources are calibrated and tested in a cryogenic environment. A Pathfinder telescope is used as a surrogate telescope for cryogenic testing of the OTIS optical test configuration. A Beam Image Analyzer (BIA) is used as a surrogate ISIM with the Pathfinder in this test. After briefly describing the OTIS optical test configuration, the paper will overview the list and configuration of significant tests of the equipment leading up to the OTIS test.

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

Mesoporous Ge/GeO2/Carbon Lithium-Ion Battery Anodes with High Capacity and High Reversibility.

PubMed

Hwang, Jongkook; Jo, Changshin; Kim, Min Gyu; Chun, Jinyoung; Lim, Eunho; Kim, Seongseop; Jeong, Sanha; Kim, Youngsik; Lee, Jinwoo

2015-05-26

We report mesoporous composite materials (m-GeO2, m-GeO2/C, and m-Ge-GeO2/C) with large pore size which are synthesized by a simple block copolymer directed self-assembly. m-Ge/GeO2/C shows greatly enhanced Coulombic efficiency, high reversible capacity (1631 mA h g(-1)), and stable cycle life compared with the other mesoporous and bulk GeO2 electrodes. m-Ge/GeO2/C exhibits one of the highest areal capacities (1.65 mA h cm(-2)) among previously reported Ge- and GeO2-based anodes. The superior electrochemical performance in m-Ge/GeO2/C arises from the highly improved kinetics of conversion reaction due to the synergistic effects of the mesoporous structures and the conductive carbon and metallic Ge.

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.

Exclusion limits on the WIMP nucleon elastic scattering cross-section from the Cryogenic Dark Matter Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golwala, Sunil Ramanlal

2000-01-01

Extensive evidence indicates that a large fraction of the matter in the universe is nonluminous, nonbaryonic, and “cold” — nonrelativistic at the time matter began to dominate the energy density of the universe. Weakly Interacting Massive Particles (WIMPs) are an excellent candidate for nonbaryonic, cold dark matter. Minimal supersymmetry provides a natural WIMP candidate in the form of the lightest superpartner, with a typical mass Mδ ~ 100 GeV c-2 . WIMPs are expected to have collapsed into a roughly isothermal, spherical halo within which the visible portion of our galaxy resides. They would scatter off nuclei via the weakmore » interaction, potentially allowingtheir direct detection. The Cryogenic Dark Matter Search (CDMS) employs Ge and Si detectors to search for WIMPs via their elastic-scatteringinteractions with nuclei while discriminatingagainst interactions of background particles. The former yield nuclear recoils while the latter produce electron recoils. The ionization yield (the ratio of ionization production to recoil energy in a semiconductor) of a particle interaction differs greatly for nuclear and electron recoils. CDMS detectors measure phonon and electron-hole-pair production to determine recoil energy and ionization yield for each event and thereby discriminate nuclear recoils from electron recoils. This dissertation reports new limits on the spin-independent WIMP-nucleon elastic-scattering cross section that exclude unexplored parameter space above 10 GeV c-2 WIMP mass and, at > 75% CL, the entire 3σ allowed region for the WIMP signal reported by the DAMA experiment. The experimental apparatus, detector performance, and data analysis are fully described.« less

Demonstration of Microsphere Insulation in Cryogenic Vessels

NASA Astrophysics Data System (ADS)

Baumgartner, R. G.; Myers, E. A.; Fesmire, J. E.; Morris, D. L.; Sokalski, E. R.

2006-04-01

While microspheres have been recognized as a legitimate insulation material for decades, actual use in full-scale cryogenic storage tanks has not been demonstrated until now. The performance and life-cycle-cost advantages previously predicted have now been proven. Most bulk cryogenic storage tanks are insulated with either multilayer insulation (MLI) or perlite. Microsphere insulation, consisting of hollow glass bubbles, combines in a single material the desirable properties that other insulations only have individually. The material has high crush strength, low density, is noncombustible, and performs well in soft vacuum. These properties were proven during recent field testing of two 22,700-L (6,000-gallon) liquid nitrogen tanks, one insulated with microsphere insulation and the other with perlite. Normal evaporation rates (NER) for both tanks were monitored with precision test equipment and insulation levels within the tanks were observed through view ports as an indication of insulation compaction. Specific industrial applications were evaluated based on the test results and beneficial properties of microsphere insulation. Over-the-road trailers previously insulated with perlite will benefit not only from the reduced heat leak, but also the reduced mass of microsphere insulation. Economic assessments for microsphere-insulated cryogenic vessels including life-cycle cost are also presented.

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

Thermodynamic Vent System for an On-Orbit Cryogenic Reaction Control Engine

NASA Technical Reports Server (NTRS)

Hurlbert, Eric A.; Romig, Kris A.; Jimenez, Rafael; Flores, Sam

2012-01-01

A report discusses a cryogenic reaction control system (RCS) that integrates a Joule-Thompson (JT) device (expansion valve) and thermodynamic vent system (TVS) with a cryogenic distribution system to allow fine control of the propellant quality (subcooled liquid) during operation of the device. It enables zero-venting when coupled with an RCS engine. The proper attachment locations and sizing of the orifice are required with the propellant distribution line to facilitate line conditioning. During operations, system instrumentation was strategically installed along the distribution/TVS line assembly, and temperature control bands were identified. A sub-scale run tank, full-scale distribution line, open-loop TVS, and a combination of procured and custom-fabricated cryogenic components were used in the cryogenic RCS build-up. Simulated on-orbit activation and thruster firing profiles were performed to quantify system heat gain and evaluate the TVS s capability to maintain the required propellant conditions at the inlet to the engine valves. Test data determined that a small control valve, such as a piezoelectric, is optimal to provide continuously the required thermal control. The data obtained from testing has also assisted with the development of fluid and thermal models of an RCS to refine integrated cryogenic propulsion system designs. This system allows a liquid oxygenbased main propulsion and reaction control system for a spacecraft, which improves performance, safety, and cost over conventional hypergolic systems due to higher performance, use of nontoxic propellants, potential for integration with life support and power subsystems, and compatibility with in-situ produced propellants.

An FPGA-based instrumentation platform for use at deep cryogenic temperatures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Conway Lamb, I. D.; Colless, J. I.; Hornibrook, J. M.

2016-01-15

We describe the operation of a cryogenic instrumentation platform incorporating commercially available field-programmable gate arrays (FPGAs). The functionality of the FPGAs at temperatures approaching 4 K enables signal routing, multiplexing, and complex digital signal processing in close proximity to cooled devices or detectors within the cryostat. The performance of the FPGAs in a cryogenic environment is evaluated, including clock speed, error rates, and power consumption. Although constructed for the purpose of controlling and reading out quantum computing devices with low latency, the instrument is generic enough to be of broad use in a range of cryogenic applications.

Cryogenic upgrade of the low heat load liquid helium cryostat used to house the Cryogenic Current Comparator in the Antiproton Decelerator at CERN

NASA Astrophysics Data System (ADS)

Lees, A.; Koettig, T.; Fernandes, M.; Tan, J.

2017-12-01

The Cryogenic Current Comparator (CCC) and its purpose built cryostat were installed in the low-energy Antiproton Decelerator (AD) at CERN in 2015. A pulse-tube cryocooler recondenses evaporated helium to liquid at 4.2 K filling the helium vessel of the cryostat at an equivalent cooling power of 0.69 W. To reduce the transmission of vibration to the highly sensitive CCC, the titanium support systems of the cryostat were optimized to be as stiff as possible while limiting the transmission of heat to the liquid helium vessel. During operation the liquid helium level in the cryostat was seen to reduce, indicating that heat load was higher than intended. To verify the reason for this additional heat load and improve the cryogenic performance of the cryostat, an upgrade was undertaken during the 2016 technical stop of the AD. This article presents the studies undertaken to understand the thermal performance of the cryostat and details the improvements made to reduce heat load on the liquid helium vessel. Also discussed are the procedures used to reduce the diffusion of helium to the vacuum space through ceramic insulators. Finally the upgraded cryogenic performance of the cryostat is presented.

Metrological analysis of a virtual flowmeter-based transducer for cryogenic helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arpaia, P., E-mail: pasquale.arpaia@unina.it; Technology Department, European Organization for Nuclear Research; Girone, M., E-mail: mario.girone@cern.ch

2015-12-15

The metrological performance of a virtual flowmeter-based transducer for monitoring helium under cryogenic conditions is assessed. At this aim, an uncertainty model of the transducer, mainly based on a valve model, exploiting finite-element approach, and a virtual flowmeter model, based on the Sereg-Schlumberger method, are presented. The models are validated experimentally on a case study for helium monitoring in cryogenic systems at the European Organization for Nuclear Research (CERN). The impact of uncertainty sources on the transducer metrological performance is assessed by a sensitivity analysis, based on statistical experiment design and analysis of variance. In this way, the uncertainty sourcesmore » most influencing metrological performance of the transducer are singled out over the input range as a whole, at varying operating and setting conditions. This analysis turns out to be important for CERN cryogenics operation because the metrological design of the transducer is validated, and its components and working conditions with critical specifications for future improvements are identified.« less

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.

Precision mechanisms for optics in a vacuum cryogenic environment

NASA Astrophysics Data System (ADS)

Navarro, R.; Elswijk, E.; Tromp, N.; Kragt, J.; Kroes, G.; Hanenburg, H.; de Haan, M.; Schuil, M.; Teuwen, M.; Janssen, H.; Venema, L.

2017-11-01

To achieve superb stability in cryogenic optical systems, NOVA-ASTRON generally designs optical instruments on the basis of a 'no adjustments' philosophy. This means that in principle no corrections are possible after assembly. The alignment precision and consequently the performance of the instrument is guaranteed from the design, the tolerance analysis and the detailed knowledge of the material behavior and manufacturing process. This resulted in a higher degree of integrated optomechanical-cryogenic design with fewer parts, but with a higher part complexity. The 'no adjustments' strategy is successful because in the end the risk on instrument performance and project delays is much reduced. Astronomical instrument specifications have become more challenging over the years. Recent designs of the European Southern Observatory Very Large Telescope Interferometer (ESO VLTI) 4 Telescope combiner MATISSE include hundreds of optical components in a cryogenic environment. Despite the large number of optical components the alignment accuracy and stability requirements are in the order of nanometers. The 'no adjustments' philosophy would be too costly in this case, because all components would need to meet extremely tight manufacturing specifications. These specifications can be relaxed dramatically if cryogenic mechanisms are used for alignment. Several mechanisms have been developed: a tip-tilt mirror mechanism, an optical path distance mechanism, a slider mechanism, a bistable cryogenic shutter and a mirror mounting clip. Key aspects of these mechanisms are that the optical element and mechanism are combined in a compact single component, driven by e.g. self braking piezo actuators in order to hold position without power. The design, realization and test results of several mechanisms are presented in this paper.

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.

A sub-Kelvin cryogen-free EPR system.

PubMed

Melhuish, Simon J; Stott, Chloe; Ariciu, Ana-Maria; Martinis, Lorenzo; McCulloch, Mark; Piccirillo, Lucio; Collison, David; Tuna, Floriana; Winpenny, Richard

2017-09-01

We present an EPR instrument built for operation at Q band below 1K. Our cryogen-free Dewar integrates with a commercial electro-magnet and bridge. A description of the cryogenic and RF systems is given, along with the adaptations to the standard EPR experiment for operation at sub-Kelvin temperatures. As a first experiment, the EPR spectra of powdered Cr 12 O 9 (OH) 3 [Formula: see text] were measured. The sub-Kelvin EPR spectra agree well with predictions, and the performance of the sub-Kelvin system at 5K is compared to that of a commercial spectrometer. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Device simulation of GeSn/GeSiSn pocket n-type tunnel field-effect transistor for analog and RF applications

NASA Astrophysics Data System (ADS)

Wang, Suyuan; Zheng, Jun; Xue, Chunlai; Li, Chuanbo; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

2017-11-01

We present the device simulations of analog and radio frequency (RF) performances of four double-gate pocket n-type tunneling field-effect transistors (NTFETs). The direct current (DC), analog and RF performances of the Ge-homo, GeSn-homo, GeSn/Ge and GeSn/GeSiSn NTFETs, are compared. The GeSn NTFETs greatly improve the on-state current (ION) and average subthreshold slope (SS), when compared with the Ge NTFET. Moreover, the GeSn/GeSiSn NTFET has the largest intrinsic gain (Av), and exhibits a suppressed ambipolar behavior, improved cut-off frequency (fT), and gain bandwidth product (GBW), according to the analyzed analog and RF figures of merit (FOM). Therefore, it can be concluded that the GeSn/GeSiSn NTFET has great potential as a promising candidate for the realization of future generation low-power analog/RF applications.

Cryogenic Orbital Nitrogen Experiment (CONE): Phase A/B design study

NASA Technical Reports Server (NTRS)

Bailey, William J.; Weiner, Stephen P.; Beekman, Douglas H.

1991-01-01

Subcritical cryogenic fluid management (CFM) has long been recognized as an enabling technology for future space missions. Subcritical liquid storage and supply are two of the five CFM technology areas that need to be studied in the low gravity on-orbit environment. The Cryogenic Orbital Nitrogen Experiment (CONE) is a LN2 cryogenic storage and supply system demonstration placed in orbit by the National Space Transportation System (NSTS) Orbiter and operated as an in-bay payload. In-space demonstration of CFM using LN2 with a few well defined areas of focus would provide the confidence level required to implement subcritical cryogen use and is the first step towards the more far reaching issue of cryogen transfer and tankage resupply. A conceptual approach for CONE was developed and an overview of the program is described including the following: (1) a description of the background and scope of the technology objectives; (2) a description of the payload design and operation; and (3) the justification for CONE relating to potential near term benefits and risk mitigation for future systems. Data and criteria is provided to correlate in-space performance with analytical and numerical modeling of CFM systems.

Assembly and performance of a 6.4 T cryogen-free dynamic nuclear polarization system.

PubMed

Kiswandhi, Andhika; Niedbalski, Peter; Parish, Christopher; Wang, Qing; Lumata, Lloyd

2017-09-01

We report on the assembly and performance evaluation of a 180-GHz/6.4 T dynamic nuclear polarization (DNP) system based on a cryogen-free superconducting magnet. The DNP system utilizes a variable-field superconducting magnet that can be ramped up to 9 T and equipped with cryocoolers that can cool the sample space with the DNP assembly down to 1.8 K via the Joule-Thomson effect. A homebuilt DNP probe insert with top-tuned nuclear magnetic resonance coil and microwave port was incorporated into the sample space in which the effective sample temperature is approximately 1.9 K when a 180-GHz microwave source is on during DNP operation. 13 C DNP of [1- 13 C] acetate samples doped with trityl OX063 and 4-oxo-TEMPO in this system have resulted in solid-state 13 C polarization levels of 58 ± 3% and 18 ± 2%, respectively. The relatively high 13 C polarization levels achieved in this work have demonstrated that the use of a cryogen-free superconducting magnet for 13 C DNP is feasible and in fact, relatively efficient-a major leap to offset the high cost of liquid helium consumption in DNP experiments. Copyright © 2017 John Wiley & Sons, Ltd.

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

NASA Astrophysics Data System (ADS)

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

2016-08-01

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

Overview of the Liquid Argon Cryogenics for the Short Baseline Neutrino Program (SBN) at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norris, Barry; Bremer, Johan; Chalifour, Michel

2017-01-01

The Short-Baseline Neutrino (SBN) physics program will involve three LAr-TPC detectors located along the Booster Neutrino Beam (BNB) at Fermilab. This new SBN Program will deliver a rich and compelling physics opportunity, including the ability to resolve a class of experimental anomalies in neutrino physics and to perform the most sensitive search to date for sterile neutrinos at the eV mass-scale through both appearance and disappearance oscillation channels. The Program will be composed of an existing and operational detector known as Micro Boone (170 ton LAr mass) plus two new experiments known as the SBN Near Detector (SBND, ~ 260more » ton) and the SBN Far Detector (SBN-FD, ~ 600 tons). Fermilab is now building two new facilities to house the experiments and incorporate all cryogenic and process systems to operate these detectors beginning in the 2018-2019 time frame. The SBN cryogenics are a collaborative effort between Fermilab and CERN. The SBN cryogenic systems for both detectors are composed of several sub-systems: External/Infrastructure (or LN2), Proximity (or LAr), and internal cryogenics. For each detector the External/Infrastructure cryogenics includes the equipment used to store and the cryogenic fluids needed for the operation of the Proximity cryogenics, including the LN2 and LAr storage facilities. The Proximity cryogenics consists of all the systems that take the cryogenic fluids from the external/infrastructure cryogenics and deliver them to the internal at the required pressure, temperature, purity and mass flow rate. It includes the condensers, the LAr and GAr purification systems, the LN2 and LAr phase separators, and the interconnecting piping. The Internal cryogenics is comprised of all the cryogenic equipment located within the cryostats themselves, including the GAr and LAr distribution piping and the piping required to cool down the cryostats and the detectors. These cryogenic systems will be engineered, manufactured, commissioned

Conceptual design of a cryogen-free μMRI device

NASA Astrophysics Data System (ADS)

Authelet, G.; Poirier-Quinot, M.; Ginefri, J.-C.; Bonelli, A.; Baudouy, B.

2017-12-01

To perform Micro Magnetic Resonance Imaging (mMRI) analysis on small regions such as skins, articulations or small animals, the required spatial resolution implies to dramatically improve the sensitivity of the detection. One way to go is to use small radio-frequency superconducting coil that allow, among others, increasing significantly the signal-to-noise ratio. The RF probe, constituted of an optimized YBaCuO film coil cooled below nitrogen temperature, must be located no further than few millimeters from the biological region to be imaged in a clinical MRI magnet. To fulfill the medical environment and constraints, a cryogen-free cooling scheme has been developed to maintain the superconducting coil at the working temperature. The cryogenic design is based on a pulse tube cryocooler and solid thermal links inserted in a non-magnetic cryostat to avoid creating any electromagnetic perturbations to the MRI magnet and the measurements. We report here the conceptual design of the cryogenic system with the required thermal performances, the corresponding layout and architecture of the system as well as the main technical challenges met for the construction.

Verification of the predictive capabilities of the 4C code cryogenic circuit model

NASA Astrophysics Data System (ADS)

Zanino, R.; Bonifetto, R.; Hoa, C.; Richard, L. Savoldi

2014-01-01

The 4C code was developed to model thermal-hydraulics in superconducting magnet systems and related cryogenic circuits. It consists of three coupled modules: a quasi-3D thermal-hydraulic model of the winding; a quasi-3D model of heat conduction in the magnet structures; an object-oriented a-causal model of the cryogenic circuit. In the last couple of years the code and its different modules have undergone a series of validation exercises against experimental data, including also data coming from the supercritical He loop HELIOS at CEA Grenoble. However, all this analysis work was done each time after the experiments had been performed. In this paper a first demonstration is given of the predictive capabilities of the 4C code cryogenic circuit module. To do that, a set of ad-hoc experimental scenarios have been designed, including different heating and control strategies. Simulations with the cryogenic circuit module of 4C have then been performed before the experiment. The comparison presented here between the code predictions and the results of the HELIOS measurements gives the first proof of the excellent predictive capability of the 4C code cryogenic circuit module.

Cryogenic Temperature Effects on Performance of Polymer Composites

NASA Technical Reports Server (NTRS)

Hui, David; Dutta, P. K.

2003-01-01

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

TankSIM: A Cryogenic Tank Performance Prediction Program

NASA Technical Reports Server (NTRS)

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

2015-01-01

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

Cryogenic Propellant Storage and Transfer Technology Demonstration For Long Duration In-Space Missions

NASA Technical Reports Server (NTRS)

Meyer, Michael L.; Motil, Susan M.; Kortes, Trudy F.; Taylor, William J.; McRight, Patrick S.

2012-01-01

The high specific impulse of cryogenic propellants can provide a significant performance advantage for in-space transfer vehicles. The upper stages of the Saturn V and various commercial expendable launch vehicles have used liquid oxygen and liquid hydrogen propellants; however, the application of cryogenic propellants has been limited to relatively short duration missions due to the propensity of cryogens to absorb environmental heat resulting in fluid losses. Utilizing advanced cryogenic propellant technologies can enable the efficient use of high performance propellants for long duration missions. Crewed mission architectures for beyond low Earth orbit exploration can significantly benefit from this capability by developing realistic launch spacing for multiple launch missions, by prepositioning stages and by staging propellants at an in-space depot. The National Aeronautics and Space Administration through the Office of the Chief Technologist is formulating a Cryogenic Propellant Storage and Transfer Technology Demonstration Mission to mitigate the technical and programmatic risks of infusing these advanced technologies into the development of future cryogenic propellant stages or in-space propellant depots. NASA is seeking an innovative path for human space exploration, which strengthens the capability to extend human and robotic presence throughout the solar system. This mission will test and validate key cryogenic technological capabilities and has the objectives of demonstrating advanced thermal control technologies to minimize propellant loss during loiter, demonstrating robust operation in a microgravity environment, and demonstrating efficient propellant transfer on orbit. The status of the demonstration mission concept development, technology demonstration planning and technology maturation activities in preparation for flight system development are described.

Simulation and experimental research of heat leakage of cryogenic transfer lines

NASA Astrophysics Data System (ADS)

Deng, B. C.; Xie, X. J.; Pan, W.; Jiang, R. X.; Li, J.; Yang, S. Q.; Li, Q.

2017-12-01

The heat leakage of cryogenic transfer lines directly influences the performance of large-scale helium refrigerator. In this paper, a thermal model of cryogenic transfer line considering numerical simulation of support coupled with MLI was established. To validate the model, test platform of cryogenic transfer lines with the merits of disassembly outer pipe and changeable easily multi-layer insulation has been built. The experimental results of heat leakage through overall length of cryogenic transfer lines, support and multi-layer insulation were obtained. The heat leakages of multi-layer insulation, a support and the overall leakage are 1.02 W/m, 0.44 W and 1.46 W/m from experimental data, respectively. The difference of heat leakage of MLI between experiment and simulation were less than 5%. The temperature distribution of support and MLI obtained in presented model in good agreement with experimental data. It is expected to reduce the overall heat leakage of cryogenic transfer lines further by optimizing structure of support based on the above thermal model and test platform in this paper.

Cryogenic filter wheel design for an infrared instrument

NASA Astrophysics Data System (ADS)

Azcue, Joaquín.; Villanueva, Carlos; Sánchez, Antonio; Polo, Cristina; Reina, Manuel; Carretero, Angel; Torres, Josefina; Ramos, Gonzalo; Gonzalez, Luis M.; Sabau, Maria D.; Najarro, Francisco; Pintado, Jesús M.

2014-09-01

In the last two decades, Spain has built up a strong IR community which has successfully contributed to space instruments, reaching Co-PI level in the SPICA mission (Space Infrared Telescope for Cosmology and Astrophysics). Under the SPICA mission, INTA, focused on the SAFARI instrument requirements but highly adaptable to other missions has designed a cryogenic low dissipation filter wheel with six positions, taking as starting point the past experience of the team with the OSIRIS instrument (ROSETTA mission) filter wheels and adapting the design to work at cryogenic temperatures. One of the main goals of the mechanism is to use as much as possible commercial components and test them at cryogenic temperature. This paper is focused on the design of the filter wheel, including the material selection for each of the main components of the mechanism, the design of elastic mount for the filter assembly, a positioner device designed to provide positional accuracy and repeatability to the filter, allowing the locking of the position without dissipation. In order to know the position of the wheel on every moment a position sensor based on a Hall sensor was developed. A series of cryogenic tests have been performed in order to validate the material configuration selected, the ball bearing lubrication and the selection of the motor. A stepper motor characterization campaign was performed including heat dissipation measurements. The result is a six position filter wheel highly adaptable to different configurations and motors using commercial components. The mechanism was successfully tested at INTA facilities at 20K at breadboard level.

Growth of Ferromagnetic Epitaxial Film of Hexagonal FeGe on (111) Ge Surface

NASA Astrophysics Data System (ADS)

Kumar, Dushyant; Joshi, P. C.; Hossain, Z.; Budhani, R. C.

2014-03-01

The realization of semiconductors showing ferromagnetic order at easily accessible temperatures has been of interest due to their potential use in spintronic devices where long spin life times are of key interest. We have realized the growth of FeGe thin films on Ge (111) wafers using pulsed laser deposition (PLD). The stoichiometric and single phase FeGe target used in PLD chamber has been made by arc melting. A typical θ-2 θ diffraction spectra performed on 40 nm thick FeGe film suggests the stabilization of β-Ni2In (B82-type) hexagonal phase with an epitaxial orientation of (0001)FeGe ||(111)Ge and [11-20]FeGe ||[-110]Ge. SEM images shows a granular structure with the formation of very large grains of about 100 to 500 nm in lateral dimension. The magnetization vs. temperature data taken from SQUID reveal the TC of ~ 270K. Since, PLD technique makes it easier to stabilize the B82 (Ni2In) hexagonal phase in thin FeGe films, this work opens opportunities to reinvestigate many conflicting results on various properties of the FeGe system.

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

NASA Technical Reports Server (NTRS)

Romanofsky, Robert R.

1996-01-01

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

Note: cryogenic low-noise dc-coupled wideband differential amplifier based on SiGe heterojunction bipolar transistors.

PubMed

Beev, Nikolai; Kiviranta, Mikko

2012-06-01

Silicon-germanium heterojunction bipolar transistors can be used to construct low-noise cryogenic amplifiers. We present a dc-coupled differential amplifier capable of operating down to 10 K. In this temperature regime it has bandwidth of 15 MHz and noise temperature as low as 1.3 K. When operated at liquid nitrogen temperature of 77 K, the measured noise temperature is lower than 3 K. The amplifier is based on the commercially available transistors NESG3031 and operational amplifier OPA836 and is capable of standalone operation without any additional stages at room temperature.

Charge Transport Phenomena in Detectors of the Cryogenic Dark Matter Search

NASA Astrophysics Data System (ADS)

Sundqvist, Kyle

2008-03-01

The Cryogenic Dark Matter Search (CDMS) seeks to detect putative weakly-interacting massive particles (WIMPS), which could explain the dark matter problem in cosmology and particle physics. By simultaneously measuring the number of charge carriers and the energy in athermal phonons created by particle interactions in intrinsic Ge and Si crystals at a temperature of 40 mK, a signature response for each event is produced. This response, combined with phonon pulse-shape information, allows CDMS to actively discriminate candidate WIMP interactions with nuclei apart from electromagnetic radioactive background which interacts with electrons. The challenges associated with these techniques are unique. Carrier drift-fields are maintained at only a few V/cm, else drift-emitted Luke-Neganov phonons would dominate the phonons of the original interaction. Under such conditions, carrier scattering is dominated by zero-point fluctuations of the lattice ions. It has been an open question how well the 8 Kelvin data prominent in the literature depicts this case. We compare the simulated transport properties of electrons and holes in <100> Ge at 40 mK and at 8 K, and apply this understanding to our detectors.

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

NASA Technical Reports Server (NTRS)

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

1975-01-01

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

Mid-infrared source with 0.2 J pulse energy based on nonlinear conversion of Q-switched pulses in ZnGeP2.

PubMed

Haakestad, Magnus W; Fonnum, Helge; Lippert, Espen

2014-04-07

Mid-infrared (3-5 μm) pulses with high energy are produced using nonlinear conversion in a ZnGeP(2)-based master oscillator-power amplifier, pumped by a Q-switched cryogenic Ho:YLF oscillator. The master oscillator is based on an optical parametric oscillator with a V-shaped 3-mirror ring resonator, and the power amplifier is based on optical parametric amplification in large-aperture ZnGeP(2) crystals. Pulses with up to 212 mJ energy at 1 Hz repetition rate are obtained, with FWHM duration 15 ns and beam quality M(2) = 3.

Two-year solid hydrogen cooler for the Cryogenic Limb Array Etalon Spectrometer (CLAES) instrument

NASA Technical Reports Server (NTRS)

Naes, L. G.; Nast, T. C.; Roche, A. E.; Forney, P. B.

1983-01-01

The Cryogenic Limb Array Etalon Spectrometer (CLAES) will be one of thirteen instruments on board the Upper Atmospheric Research Satellite (UARS) in late 1988. CLAES is to be employed for the measurement of stratospheric trace species concentrations affecting the ozone layer balance. It is an earth-limb viewing instrument which requires cryogenic cooling in order to obtain the necessary performance sensitivity. The present investigation is concerned with the solid hydrogen cryogen subsystem which provides the instrument temperature needed. Attention is given to the studies which led to the selection of solid hydrogen as cooling agent, the baseline cooler system, aspects of baseline performance sensitivity, and nominal cooler operations.

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

NASA Technical Reports Server (NTRS)

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

2003-01-01

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

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.

Concept Design of Cryogenic Propellant Storage and Transfer for Space Exploration

NASA Technical Reports Server (NTRS)

Free, James M.; Motil, Susan M.; Kortes, Trudy F.; Meyer, Michael L.; taylor, William J.

2012-01-01

NASA is in the planning and investigation process of developing innovative paths for human space exploration that strengthen the capability to extend human and robotic presence beyond low Earth orbit and throughout the solar system. NASA is establishing the foundations to enable humans to safely reach multiple potential destinations, including the Moon, asteroids, Lagrange points, and Mars and its environs through technology and capability development. To achieve access to these destinations within a reasonable flight time will require the use of high performance cryogenic propulsion systems. Therefore NASA is examining mission concepts for a Cryogenic Propellant Storage and Transfer (CPST) Flight Demonstration which will test and validate key capabilities and technologies required for future exploration elements such as large cryogenic propulsion stages and propellant depots. The CPST project will perform key ground testing in fiscal year 2012 and execute project formulation and implementation leading to a flight demonstration in 2017.

Cryogenics for HL-LHC

NASA Astrophysics Data System (ADS)

Tavian, L.; Brodzinski, K.; Claudet, S.; Ferlin, G.; Wagner, U.; van Weelderen, R.

The discovery of a Higgs boson at CERN in 2012 is the start of a major program of work to measure this particle's properties with the highest possible precision for testing the validity of the Standard Model and to search for further new physics at the energy frontier. The LHC is in a unique position to pursue this program. Europe's top priority is the exploitation of the full potential of the LHC, including the high-luminosity upgrade of the machine and detectors with an objective to collect ten times more data than in the initial design, by around 2030. To reach this objective, the LHC cryogenic system must be upgraded to withstand higher beam current and higher luminosity at top energy while keeping the same operation availability by improving the collimation system and the protection of electronics sensitive to radiation. This chapter will present the conceptual design of the cryogenic system upgrade with recent updates in performance requirements, the corresponding layout and architecture of the system as well as the main technical challenges which have to be met in the coming years.

Vent System Analysis for the Cryogenic Propellant Storage Transfer Ground Test Article

NASA Technical Reports Server (NTRS)

Hedayat, A

2013-01-01

To test and validate key capabilities and technologies required for future exploration elements such as large cryogenic propulsion stages and propellant depots, NASA is leading the efforts to develop and design the Cryogenic Propellant Storage and Transfer (CPST) Cryogenic Fluid Management (CFM) payload. The primary objectives of CPST payload are to demonstrate: 1) in-space storage of cryogenic propellants for long duration applications; and 2) in-space transfer of cryogenic propellants. The Ground Test Article (GTA) is a technology development version of the CPST payload. The GTA consists of flight-sized and flight-like storage and transfer tanks, liquid acquisition devices, transfer, and pressurization systems with all of the CPST functionality. The GTA is designed to perform integrated passive and active thermal storage and transfer performance testing with liquid hydrogen (LH2) in a vacuum environment. The GTA storage tank is designed to store liquid hydrogen and the transfer tank is designed to be 5% of the storage tank volume. The LH2 transfer subsystem is designed to transfer propellant from one tank to the other utilizing pressure or a pump. The LH2 vent subsystem is designed to prevent over-pressurization of the storage and transfer tanks. An in-house general-purpose computer program was utilized to model and simulate the vent subsystem operation. The modeling, analysis, and the results will be presented in the final paper.

Long-Term Cryogenic Propellant Storage for the Titan Orbiter Polar Surveyor (TOPS) Mission

NASA Technical Reports Server (NTRS)

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

ERTS-C (Landsat 3) cryogenic heat pipe experiment definition

NASA Technical Reports Server (NTRS)

Brennan, P. J.; Kroliczek, E. J.

1975-01-01

A flight experiment designed to demonstrate current cryogenic heat pipe technology was defined and evaluated. The experiment package developed is specifically configured for flight aboard an ERTS type spacecraft. Two types of heat pipes were included as part of the experiment package: a transporter heat pipe and a thermal diode heat pipe. Each was tested in various operating modes. Performance data obtained from the experiment are applicable to the design of cryogenic systems for detector cooling, including applications where periodic high cooler temperatures are experienced as a result of cyclic energy inputs.

Micromechanics, Fracture Mechanics and Gas Permeability of Composite Laminates for Cryogenic Storage Systems

NASA Technical Reports Server (NTRS)

Choi, Sukjoo; Sankar, Bhavani; Ebaugh, Newton C.

2005-01-01

A micromechanics method is developed to investigate microcrack propagation in a liquid hydrogen composite tank at cryogenic temperature. The unit cell is modeled using square and hexagonal shapes depends on fiber and matrix layout from microscopic images of composite laminates. Periodic boundary conditions are applied to the unit cell. The temperature dependent properties are taken into account in the analysis. The laminate properties estimated by the micromechanics method are compared with empirical solutions using constituent properties. The micro stresses in the fiber and matrix phases based on boundary conditions in laminate level are calculated to predict the formation of microcracks in the matrix. The method is applied to an actual liquid hydrogen storage system. The analysis predicts micro stresses in the matrix phase are large enough to cause microcracks in the composite. Stress singularity of a transverse crack normal to a ply-interface is investigated to predict the fracture behavior at cryogenic conditions using analytical and finite element analysis. When a transverse crack touches a ply-interface of a composite layer with same fiber orientation, the stress singularity is equal to 1/2. When the transverse crack propagates to a stiffer layer normal to the ply-direction, the singularity becomes less than 1/2 and vice versa. Finite element analysis is performed to predict the fracture toughness of a laminated beam subjected to fracture loads measured by four-point bending tests at room and cryogenic temperatures. As results, the fracture load at cryogenic temperature is significantly lower than that at room temperature. However, when thermal stresses are taken into consideration, for both cases of room and cryogenic temperatures, the difference of the fracture toughness becomes insignificant. The result indicates fracture toughness is a characteristic property, which is independent to temperature changes. The experimental analysis is performed to

Microminiature linear split Stirling cryogenic cooler for portable infrared imagers

NASA Astrophysics Data System (ADS)

Veprik, A.; Vilenchik, H.; Riabzev, S.; Pundak, N.

2007-04-01

Novel tactics employed in carrying out military and antiterrorist operations call for the development of a new generation of warfare, among which sophisticated portable infrared (IR) imagers for surveillance, reconnaissance, targeting and navigation play an important role. The superior performance of such imagers relies on novel optronic technologies and maintaining the infrared focal plane arrays at cryogenic temperatures using closed cycle refrigerators. Traditionally, rotary driven Stirling cryogenic engines are used for this purpose. As compared to their military off-theshelf linear rivals, they are lighter, more compact and normally consume less electrical power. Latest technological advances in industrial development of high-temperature (100K) infrared detectors initialized R&D activity towards developing microminiature cryogenic coolers, both of rotary and linear types. On this occasion, split linearly driven cryogenic coolers appear to be more suitable for the above applications. Their known advantages include flexibility in the system design, inherently longer life time, low vibration export and superior aural stealth. Moreover, recent progress in designing highly efficient "moving magnet" resonant linear drives and driving electronics enable further essential reduction of the cooler size, weight and power consumption. The authors report on the development and project status of a novel Ricor model K527 microminiature split Stirling linear cryogenic cooler designed especially for the portable infrared imagers.

Heat switch technology for cryogenic thermal management

NASA Astrophysics Data System (ADS)

Shu, Q. S.; Demko, J. A.; E Fesmire, J.

2017-12-01

Systematic review is given of development of novel heat switches at cryogenic temperatures that alternatively provide high thermal connection or ideal thermal isolation to the cold mass. These cryogenic heat switches are widely applied in a variety of unique superconducting systems and critical space applications. The following types of heat switch devices are discussed: 1) magnetic levitation suspension, 2) shape memory alloys, 3) differential thermal expansion, 4) helium or hydrogen gap-gap, 5) superconducting, 6) piezoelectric, 7) cryogenic diode, 8) magneto-resistive, and 9) mechanical demountable connections. Advantages and limitations of different cryogenic heat switches are examined along with the outlook for future thermal management solutions in materials and cryogenic designs.

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.

Experimental evaluation of a tuned electromagnetic damper for vibration control of cryogenic turbopump rotors

NASA Technical Reports Server (NTRS)

Dirusso, Eliseo; Brown, Gerald V.

1990-01-01

Experiments were performed on a passive tuned electromagnetic damper that could be used for damping rotor vibrations in cryogenic turbopumps for rocket engines. The tests were performed in a rig that used liquid nitrogen to produce cryogenic turbopump temperatures. This damper is most effective at cryogenic temperatures and is not a viable damper at room temperature. The unbalanced amplitude response of the rotor shaft was measured for undamped (baseline) and damped conditions at the critical speeds of the rotor (approx. 5900 to 6400 rpm) and the data were compared. The tests were performed for a speed range between 900 and 10 000 rpm. The tests revealed that the damper is very effective for damping single-mode narrow bandwidth amplitude response but is less effective in damping broadband response or multimode amplitude response.

Design of a magnetic circuit for a cryogenic undulator in Taiwan photon source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Jui-Che, E-mail: huang.juiche@nsrrc.org.tw; Kuo, Cheng-Ying; Yang, Chin-Kang

2016-07-27

The plan for beamlines in Phase II at Taiwan Photon Source is to construct two new BioSAXS and nano-ARPES beamlines. A highly brilliant light source can be produced with a cryogenic undulator, and many synchrotron facilities have been developed and operated with these in their storage rings. The development of a cryogenic undulator became a target for a light source in TPS phase II. A cryogenic undulator with period of length 15 mm will be made in a hybrid magnetic structure, and use PrFeB permanent-magnet materials. A maximum magnetic field 1.31 T is estimated at gap 4 mm and temperaturemore » about 100 K. The spectral performance of a TPS cryogenic undulator is presented in this paper.« less

Introduction to cryogenic wind tunnels

NASA Technical Reports Server (NTRS)

Goodyer, M. J.

1985-01-01

The background to the evolution of the cryogenic wind tunnel is outlined, with particular reference to the late 60's/early 70's when efforts were begun to re-equip with larger wind tunnels. The problems of providing full scale Reynolds numbers in transonic testing were proving particularly intractible, when the notion of satisfying the needs with the cryogenic tunnel was proposed, and then adopted. The principles and advantages of the cryogenic tunnel are outlined, along with guidance on the coolant needs when this is liquid nitrogen, and with a note on energy recovery. Operational features of the tunnels are introduced with reference to a small low speed tunnel. Finally the outstanding contributions are highlighted of the 0.3-Meter Transonic Cryogenic Tunnel (TCT) at NASA Langley Research Center, and its personnel, to the furtherance of knowledge and confidence in the concept.

Design and Testing of a Cryogenic Capillary Pumped Loop Flight Experiment

NASA Technical Reports Server (NTRS)

Bugby, David C.; Kroliczek, Edward J.; Ku, Jentung; Swanson, Ted; Tomlinson, B. J.; Davis, Thomas M.; Baumann, Jane; Cullimore, Brent

1998-01-01

This paper details the flight configuration and pre-flight performance test results of the fifth generation cryogenic capillary pumped loop (CCPL-5). This device will fly on STS-95 in October 1998 as part of the CRYOTSU Flight Experiment. This flight represents the first in-space demonstration of a CCPL, a miniaturized two-phase fluid circulator for thermally linking cryogenic cooling sources to remote cryogenic components. CCPL-5 utilizes N2 as the working fluid and has a practical operating range of 75-110 K. Test results indicate that CCPL-5, which weighs about 200 grams, can transport over 10 W of cooling a distance of 0.25 m (or more) with less than a 5 K temperature drop.

Ultra-high-mass mass spectrometry with charge discrimination using cryogenic detectors

DOEpatents

Frank, Matthias; Mears, Carl A.; Labov, Simon E.; Benner, W. Henry

1999-01-01

An ultra-high-mass time-of-flight mass spectrometer using a cryogenic particle detector as an ion detector with charge discriminating capabilities. Cryogenic detectors have the potential for significantly improving the performance and sensitivity of time-of-flight mass spectrometers, and compared to ion multipliers they exhibit superior sensitivity for high-mass, slow-moving macromolecular ions and can be used as "stop" detectors in time-of-flight applications. In addition, their energy resolving capability can be used to measure the charge state of the ions. Charge discrimination is very valuable in all time-of-flight mass spectrometers. Using a cryogenically-cooled Nb-Al.sub.2 O.sub.3 -Nb superconductor-insulator-superconductor (SIS) tunnel junction (STJ) detector operating at 1.3 K as an ion detector in a time-of-flight mass spectrometer for large biomolecules it was found that the STJ detector has charge discrimination capabilities. Since the cryogenic STJ detector responds to ion energy and does not rely on secondary electron production, as in the conventionally used microchannel plate (MCP) detectors, the cryogenic detector therefore detects large molecular ions with a velocity-independent efficiency approaching 100%.

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.

Photoluminescence and electroluminescence from Ge/strained GeSn/Ge quantum wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Chung-Yi; Chang, Chih-Chiang; Huang, Chih-Hsiung

2016-08-29

Ge/strained GeSn/Ge quantum wells are grown on a 300 mm Si substrate by chemical vapor deposition. The direct bandgap emission from strained GeSn is observed in the photoluminescence spectra and is enhanced by Al{sub 2}O{sub 3}/SiO{sub 2} passivation due to the field effect. The electroluminescence of the direct bandgap emission of strained GeSn is also observed from the Ni/Al{sub 2}O{sub 3}/GeSn metal-insulator-semiconductor tunneling diodes. Electroluminescence is a good indicator of GeSn material quality, since defects in GeSn layers degrade the electroluminescence intensity significantly. At the accumulation bias, the holes in the Ni gate electrode tunnel to the strained n-type GeSn layermore » through the ultrathin Al{sub 2}O{sub 3} and recombine radiatively with electrons. The emission wavelength of photoluminescence and electroluminescence can be tuned by the Sn content.« less

Fabrication of Ge-on-insulator wafers by Smart-CutTM with thermal management for undamaged donor Ge wafers

NASA Astrophysics Data System (ADS)

Kim, Munho; Cho, Sang June; Jayeshbhai Dave, Yash; Mi, Hongyi; Mikael, Solomon; Seo, Jung-Hun; Yoon, Jung U.; Ma, Zhenqiang

2018-01-01

Newly engineered substrates consisting of semiconductor-on-insulator are gaining much attention as starting materials for the subsequent transfer of semiconductor nanomembranes via selective etching of the insulating layer. Germanium-on-insulator (GeOI) substrates are critically important because of the versatile applications of Ge nanomembranes (Ge NMs) toward electronic and optoelectronic devices. Among various fabrication techniques, the Smart-CutTM technique is more attractive than other methods because a high temperature annealing process can be avoided. Another advantage of Smart-CutTM is the reusability of the donor Ge wafer. However, it is very difficult to realize an undamaged Ge wafer because there exists a large mismatch in the coefficient of thermal expansion among the layers. Although an undamaged donor Ge wafer is a prerequisite for its reuse, research related to this issue has not yet been reported. Here we report the fabrication of 4-inch GeOI substrates using the direct wafer bonding and Smart-CutTM process with a low thermal budget. In addition, a thermo-mechanical simulation of GeOI was performed by COMSOL to analyze induced thermal stress in each layer of GeOI. Crack-free donor Ge wafers were obtained by annealing at 250 °C for 10 h. Raman spectroscopy and x-ray diffraction (XRD) indicated similarly favorable crystalline quality of the Ge layer in GeOI compared to that of bulk Ge. In addition, Ge p-n diodes using transferred Ge NM indicate a clear rectifying behavior with an on and off current ratio of 500 at ±1 V. This demonstration offers great promise for high performance transferrable Ge NM-based device applications.

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.

Modeling the Rapid Boil-Off of a Cryogenic Liquid When Injected into a Low Pressure Cavity

NASA Technical Reports Server (NTRS)

Lira, Eric

2016-01-01

Many launch vehicle cryogenic applications require the modeling of injecting a cryogenic liquid into a low pressure cavity. The difficulty of such analyses lies in accurately predicting the heat transfer coefficient between the cold liquid and a warm wall in a low pressure environment. The heat transfer coefficient and the behavior of the liquid is highly dependent on the mass flow rate into the cavity, the cavity wall temperature and the cavity volume. Testing was performed to correlate the modeling performed using Thermal Desktop and Sinda Fluint Thermal and Fluids Analysis Software. This presentation shall describe a methodology to model the cryogenic process using Sinda Fluint, a description of the cryogenic test set up, a description of the test procedure and how the model was correlated to match the test results.

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.

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

NASA Technical Reports Server (NTRS)

Balakrishna, S.; Kilgore, W. Allen

1995-01-01

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

Cryogenic actuator testing for the SAFARI ground calibration setup

NASA Astrophysics Data System (ADS)

de Jonge, C.; Eggens, M.; Nieuwenhuizen, A. C. T.; Detrain, A.; Smit, H.; Dieleman, P.

2012-09-01

For the on-ground calibration setup of the SAFARI instrument cryogenic mechanisms are being developed at SRON Netherlands Institute for Space Research, including a filter wheel, XYZ-scanner and a flipmirror mechanism. Due to the extremely low background radiation requirement of the SAFARI instrument, all of these mechanisms will have to perform their work at 4.5 Kelvin and low-dissipative cryogenic actuators are required to drive these mechanisms. In this paper, the performance of stepper motors, piezoelectric actuators and brushless DC-motors as cryogenic actuators are compared. We tested stepper motor mechanical performance and electrical dissipation at 4K. The actuator requirements, test setup and test results are presented. Furthermore, design considerations and early performance tests of the flipmirror mechanism are discussed. This flipmirror features a 102 x 72 mm aluminum mirror that can be rotated 45°. A Phytron stepper motor with reduction gearbox has been chosen to drive the flipmirror. Testing showed that this motor has a dissipation of 49mW at 4K with a torque of 60Nmm at 100rpm. Thermal modeling of the flipmirror mechanism predicts that with proper thermal strapping the peak temperature of the flipmirror after a single action will be within the background level requirements of the SAFARI instrument. Early tests confirm this result. For low-duty cycle operations commercial stepper motors appear suitable as actuators for test equipment in the SAFARI on ground calibration setup.

Cryogenic Hydrogen Fuel for Controlled Inertial Confinement Fusion (Cryogenic Target Factory Concept Based on FST-Layering Method)

NASA Astrophysics Data System (ADS)

Aleksandrova, I. V.; Koresheva, E. R.; Koshelev, I. E.; Krokhin, O. N.; Nikitenko, A. I.; Osipov, I. E.

2017-12-01

A central element of a power plant based on inertial confinement fusion (ICF) is a target with cryogenic hydrogen fuel that should be delivered to the center of a reactor chamber with a high accuracy and repetition rate. Therefore, a cryogenic target factory (CTF) is an integral part of any ICF reactor. A promising way to solve this problem consists in the FST layering method developed at the Lebedev Physical Institute (LPI). This method (rapid fuel layering inside moving free-standing targets) is unique, having no analogs in the world. The further development of FST-layering technologies is implemented in the scope of the LPI program for the creation of a modular CTF and commercialization of the obtained results. In this report, we discuss our concept of CTF (CTF-LPI) that exhibits the following distinctive features: using a FST-layering technology for the elaboration of an in-line production of cryogenic targets, using an effect of quantum levitation of high-temperature superconductors (HTSCs) in magnetic field for noncontacting manipulation, transport, and positioning of the free-standing cryogenic targets, as well as in using a Fourier holography technique for an on-line characterization and tracking of the targets flying into the reactor chamber. The results of original experimental and theoretical investigations performed at LPI indicate that the existing and developing target fabrication capabilities and technologies can be applied to ICF target production. The unique scientific, engineering, and technological base developed in Russia at LPI allows one to make a CTFLPI prototype for mass production of targets and delivery thereof at the required velocity into the ICF reactor chamber.

Harnessing the concurrent reaction dynamics in active Si and Ge to achieve high performance lithium-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Qiaobao; Chen, Huixin; Luo, Langli

Advanced composite electrodes containing multiple active components are often used in lithium-ion batteries for practical applications. The performance of such heterogeneous composite electrodes can in principle be enhanced by tailoring the concurrent reaction dynamics in multiple active components for promoting their collective beneficial effects. However, the potential of this design principle has remained uncharted to date. Here we develop a composite anode of Cu/Si/Ge nanowire arrays, where each nanowire consists of a core of Cu segments and a Si/Ge bilayer shell. This unique electrode architecture exhibited a markedly improved electrochemical performance over the reference Cu/Si systems, demonstrating a stable capacitymore » retention (81% after 3000 cycles at 2C) and doubled specific capacity at a rate of 16C (1C = 2 A g1). By using in situ transmission electron microscopy and electrochemical testing, we unravel a novel reaction mechanism of dynamic co-lithiation/co-delithiation in the active Si and Ge bilayer, which is shown to effectively alleviate the electrochemically induced mechanical degradation and thus greatly enhance the long-cycle stability of the electrode. Our findings offer insights into a rational design of high-performance lithium-ion batteries via exploiting the concurrent reaction dynamics in the multiple active components of composite electrodes.A composite anode of Cu/Si/Ge nanowire arrays grown on a porous Ni foam enables the outstanding capacity, rate capability and cycle stability of Li-ion batteries.« less

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.

Development of a cryogenic rotating heat pipe joint

NASA Technical Reports Server (NTRS)

1978-01-01

The performance of two critical technology components required for a continuously rotatable heat pipe: (1) a low-leakage rotatable coupling for the heat pipe pressure vessel, and (2) a rotatable internal wick, is reported. Performance and leakage requirements were established based on 12 months operation of a cryogenic rotatable heat pipe on a satellite in earth orbit.

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.

Study of Optical Fiber Sensors for Cryogenic Temperature Measurements.

PubMed

De Miguel-Soto, Veronica; Leandro, Daniel; Lopez-Aldaba, Aitor; Beato-López, Juan Jesus; Pérez-Landazábal, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Lopez-Amo, Manuel

2017-11-30

In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser have been studied. Their sensitivities and resolutions as sensors for cryogenic temperatures have been compared regarding their advantages and disadvantages. Additionally, the results have been compared with the given by a commercial optical backscatter reflectometer that allowed for distributed temperature measurements of a single mode fiber.

Study of Optical Fiber Sensors for Cryogenic Temperature Measurements

PubMed Central

Leandro, Daniel; Lopez-Aldaba, Aitor; Beato-López, Juan Jesus; Pérez-Landazábal, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; Lopez-Amo, Manuel

2017-01-01

In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg grating (FBG), and a π-phase shifted fiber Bragg grating interrogated in a random distributed feedback fiber laser have been studied. Their sensitivities and resolutions as sensors for cryogenic temperatures have been compared regarding their advantages and disadvantages. Additionally, the results have been compared with the given by a commercial optical backscatter reflectometer that allowed for distributed temperature measurements of a single mode fiber. PMID:29189755

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

NASA Astrophysics Data System (ADS)

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

2016-03-01

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

Cryogenic Test Capability at Marshall Space Flight Center's X-ray Cryogenic Test Facility

NASA Technical Reports Server (NTRS)

Kegley, Jeffrey; Baker, Mark; Carpenter, Jay; Eng, Ron; Haight, Harlan; Hogue, William; McCracken, Jeff; Siler, Richard; Wright, Ernie

2006-01-01

Marshall Space Flight Center's X-ray & Cryogenic Test Facility (XRCF) has been performing sub-liquid nitrogen temperature testing since 1999. Optical wavefront measurement, thermal structural deformation, mechanism functional & calibration, and simple cryo-conditioning tests have been completed. Recent modifications have been made to the facility in support of the James Webb Space Telescope (JWST) program. The chamber's payload envelope and the facility s refrigeration capacity have both been increased. Modifications have also been made to the optical instrumentation area improving access for both the installation and operation of optical instrumentation outside the vacuum chamber. The facility's capabilities, configuration, and performance data will be presented.

Shuttle: Reaction control system. Cryogenic liquid distribution system: Study

NASA Technical Reports Server (NTRS)

Akkerman, J. W.

1972-01-01

A cryogenic liquid distribution system suitable for the reaction control system on space shuttles is described. The system thermodynamics, operation, performance and weight analysis are discussed along with the design, maintenance and integration concepts.

Overview of RICOR tactical cryogenic refrigerators for space missions

NASA Astrophysics Data System (ADS)

Riabzev, Sergey; Filis, Avishai; Livni, Dorit; Regev, Itai; Segal, Victor; Gover, Dan

2016-05-01

Cryogenic refrigerators represent a significant enabling technology for Earth and Space science enterprises. Many of the space instruments require cryogenic refrigeration to enable the use of advanced detectors to explore a wide range of phenomena from space. RICOR refrigerators involved in various space missions are overviewed in this paper, starting in 1994 with "Clementine" Moon mission, till the latest ExoMars mission launched in 2016. RICOR tactical rotary refrigerators have been incorporated in many space instruments, after passing qualification, life time, thermal management testing and flight acceptance. The tactical to space customization framework includes an extensive characterization and qualification test program to validate reliability, the design of thermal interfacing with a detector, vibration export control, efficient heat dissipation in a vacuum environment, robustness, mounting design, compliance with outgassing requirements and strict performance screening. Current RICOR development is focused on dedicated ultra-long-life, highly reliable, space cryogenic refrigerator based on a Pulse Tube design

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.

Effects of Cryogenic Temperatures on Spacecraft Internal Dielectric Discharges

NASA Technical Reports Server (NTRS)

Ferguson, Dale c.; Schneider, Todd A.; Vaughn, Jason A.

2009-01-01

Abstract Most calculations of internal dielectric charging on spacecraft use tabulated values of material surface and bulk conductivities, dielectric constants, and dielectric breakdown strengths. Many of these properties are functions of temperature, and the temperature dependences are not well known. At cryogenic temperatures, where it is well known that material conductivities decrease dramatically, it is an open question as to the timescales over which buried charge will dissipate and prevent the eventual potentially disastrous discharges of dielectrics. In this paper, measurements of dielectric charging and discharging for cable insulation materials at cryogenic temperatures (approx. 90 K) are presented using a broad spectrum electron source at the NASA Marshall Space Flight Center. The measurements were performed for the James Webb Space Telescope (JWST), which will orbit at the Earth-Sun L2 point, and parts of which will be perennially at temperatures as low as 40 K. Results of these measurements seem to show that Radiation Induced Conductivity (RIC) under cryogenic conditions at L2 will not be sufficient to allow charges to bleed off of some typical cable insulation materials even over the projected JWST lifetime of a dozen years or more. After the charging and discharging measurements are presented, comparisons are made between the material conductivities that can be inferred from the measured discharges and conductivities calculated from widely used formulae. Furthermore, the measurement-inferred conductivities are compared with extrapolations of recent measurements of materials RIC and dark conductivities performed with the charge-storage method at Utah State University. Implications of the present measurements are also given for other spacecraft that may operate at cryogenic temperatures, such as probes of the outer planets or the permanently dark cratered areas on the moon. The present results will also be of interest to those who must design or

Design progress of cryogenic hydrogen system for China Spallation Neutron Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, G. P.; Zhang, Y.; Xiao, J.

2014-01-29

China Spallation Neutron Source (CSNS) is a large proton accelerator research facility with 100 kW beam power. Construction started in October 2011 and is expected to last 6.5 years. The cryogenic hydrogen circulation is cooled by a helium refrigerator with cooling capacity of 2200 W at 20 K and provides supercritical hydrogen to neutron moderating system. Important progresses of CSNS cryogenic system were concluded as follows. Firstly, process design of cryogenic system has been completed including helium refrigerator, hydrogen loop, gas distribution, and safety interlock. Secondly, an accumulator prototype was designed to mitigate pressure fluctuation caused by dynamic heat loadmore » from neutron moderation. Performance test of the accumulator has been carried out at room and liquid nitrogen temperature. Results show the accumulator with welding bellows regulates hydrogen pressure well. Parameters of key equipment have been identified. The contract for the helium refrigerator has been signed. Mechanical design of the hydrogen cold box has been completed, and the hydrogen pump, ortho-para hydrogen convertor, helium-hydrogen heat exchanger, hydrogen heater, and cryogenic valves are in procurement. Finally, Hydrogen safety interlock has been finished as well, including the logic of gas distribution, vacuum, hydrogen leakage and ventilation. Generally, design and construction of CSNS cryogenic system is conducted as expected.« less

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.

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.

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)

Shuttle cryogenic supply system optimization study. Volume 5A-1: Users manual for math models

NASA Technical Reports Server (NTRS)

1973-01-01

The Integrated Math Model for Cryogenic Systems is a flexible, broadly applicable systems parametric analysis tool. The program will effectively accommodate systems of considerable complexity involving large numbers of performance dependent variables such as are found in the individual and integrated cryogen systems. Basically, the program logic structure pursues an orderly progression path through any given system in much the same fashion as is employed for manual systems analysis. The system configuration schematic is converted to an alpha-numeric formatted configuration data table input starting with the cryogen consumer and identifying all components, such as lines, fittings, and valves, each in its proper order and ending with the cryogen supply source assembly. Then, for each of the constituent component assemblies, such as gas generators, turbo machinery, heat exchangers, and accumulators, the performance requirements are assembled in input data tabulations. Systems operating constraints and duty cycle definitions are further added as input data coded to the configuration operating sequence.

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

NASA Astrophysics Data System (ADS)

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

2017-04-01

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

Use of thermal sieve to allow optical testing of cryogenic optical systems.

PubMed

Kim, Dae Wook; Cai, Wenrui; Burge, James H

2012-05-21

Full aperture testing of large cryogenic optical systems has been impractical due to the difficulty of operating a large collimator at cryogenic temperatures. The Thermal Sieve solves this problem by acting as a thermal barrier between an ambient temperature collimator and the cryogenic system under test. The Thermal Sieve uses a set of thermally controlled baffles with array of holes that are lined up to pass the light from the collimator without degrading the wavefront, while attenuating the thermal background by nearly 4 orders of magnitude. This paper provides the theory behind the Thermal Sieve system, evaluates the optimization for its optical and thermal performance, and presents the design and analysis for a specific system.

Cryogenic Refractive Index of Heraeus Homosil Glass

NASA Technical Reports Server (NTRS)

Miller, Kevin H.; Quijada, Manuel A.; Leviton, Douglas B.

2017-01-01

This paper reports measurements of the refractive index of Homosil (Heraeus) over the wavelength range of 0.343.16 m and temperature range of 120335 K. These measurements were performed by using the Cryogenic High Accuracy Refraction Measuring System (CHARMS) facility at the NASAs Goddard Space Flight Center. These measurements were in support of an integrated Structural-Thermal-Optical-Performance (STOP) model that was developed for a field-widened Michelson interferometer that is being built and tested for the High Spectral Resolution Lidar (HSRL) project at the NASA Langley Research Center (LaRC). The cryogenic refractive index measurements were required in order to account for the highly sensitivity performance of the HSRL instrument to changes in refractive index with temperature, temperature gradients, thermal expansion, and deformation due to mounting stresses. A dense coverage of the absolute refractive index over the aforementioned wavelength and temperature ranges was used to determine the thermo-optic coefficient (dndT) and dispersion relation (dnd) as a function of wavelength and temperature. Our measurements of Homosil will be compared with measurements of other glasses from the fused silica family studied in CHARMS as well as measurements reported elsewhere in literature.

Cryogenic Refractive Index of Heraeus Homosil Glass

NASA Technical Reports Server (NTRS)

Miller, Kevin H.; Quijada, Manuel A.; Leviton, Douglas B.

2017-01-01

This paper reports measurements of the refractive index of Homosil (Heraeus) over the wavelength range of 0.34-3.16 microns and temperature range of 120-335 K. These measurements were performed by using the Cryogenic High Accuracy Refraction Measuring System (CHARMS) facility at the NASAs Goddard Space Flight Center. These measurements were in support of an integrated Structural-Thermal-Optical-Performance (STOP) model that was developed for a field-widened Michelson interferometer that is being built and tested for the High Spectral Resolution Lidar (HSRL) project at the NASA Langley Research Center (LaRC). The cryogenic refractive index measurements were required in order to account for the highly sensitivity performance of the HSRL instrument to changes in refractive index with temperature, temperature gradients, thermal expansion, and deformation due to mounting stresses. A dense coverage of the absolute refractive index over the aforementioned wavelength and temperature ranges was used to determine the thermo-optic coefficient (dn/dT) and dispersion relation (dn/d(lamda)) as a function of wavelength and temperature. Our measurements of Homosil will be compared with measurements of other glasses from the fused silica family studied in CHARMS as well as measurements reported elsewhere in literature.

Periodic flow hydrodynamic resistance parameters for woven screen matrices at cryogenic temperatures

NASA Astrophysics Data System (ADS)

Perrella, M. D.; Ghiaasiaan, S. M.

2017-12-01

The regenerator is a critical component in all Stirling and Pulse Tube cryocoolers. It generally consists of a microporous metallic or rare-earth filler material contained within a cylindrical shell. Accurate modelling of the hydrodynamic and thermal behaviour of different regenerator materials is crucial to the successful design of cryogenic systems. Previous investigations have used experimental measurements at steady and periodic flow conditions in conjunction with pore-level CFD analysis to determine the pertinent hydrodynamic parameters, namely the Darcy permeability and Forchheimer coefficients. Due to the difficulty associated with experimental measurement at cryogenic temperatures, past investigations were mostly performed at ambient conditions and their results are assumed to be appropriate for cryogenic temperatures. In this study, a regenerator filled with woven screen matrices such as 400 mesh T316 stainless steel were assembled and experimentally tested under periodic helium flow at cryogenic temperatures. The mass flow and pressure drop data were analysed using CFD to determine the dimensionless friction factor, Darcy Permeability and Forchheimer coefficients. These results are compared to previous investigations at ambient temperature conditions, and the relevance of room-temperature models and correlations to cryogenic temperatures is critically assessed.

Characterization of SiPM for cryogenic applications

NASA Astrophysics Data System (ADS)

Cervi, T.; Bonesini, M.; Falcone, A.; Menegolli, A.; Raselli, G. L.; Rossella, M.; Simonetta, M.; Torti, M.

2016-07-01

The development of detectors based on liquefied noble gas (LAr, LXe) is mandatory for experiments dedicated to study physics beyond the Standard Model. For this purpose, it is fundamental to detect the Vacuum Ultra Violet (VUV) scintillation light, produced after the passage of ionizing particles inside the detector sensitive volume, to be used for trigger, timing and calorimetric purposes. Besides the traditional cryogenic Photo-Multiplier Tubes (PMTs), one possibility is to adopt Silicon Photo-Multipliers (SiPMs). We present a comparison of the performance of a SiPM (mod. ASD-NUV3S-P Low Afterpulse) at various cryogenic temperatures, from 60 K up to room temperature, with particular emphasis on the LAr and LXe temperatures. SiPM were characterized in terms of breakdown voltage, gain, pulse shape response, dark count rate and correlated noise.

Broadband Ge/SiGe quantum dot photodetector on pseudosubstrate

PubMed Central

2013-01-01

We report the fabrication and characterization of a ten-period Ge quantum dot photodetector grown on SiGe pseudosubstrate. The detector exhibits tunable photoresponse in both 3- to 5- μm and 8- to 12- μm spectral regions with responsivity values up to about 1 mA/W at a bias of −3 V and operates under normal incidence radiation with background limited performance at 100 K. The relative response in the mid- and long-wave atmospheric windows could be controlled through the applied voltage. PMID:23651470

Numerical Modeling of Thermofluid Transients During Chilldown of Cryogenic Transfer Lines

NASA Technical Reports Server (NTRS)

Majumdar, Alok; Steadman, Todd

2003-01-01

The chilldown of fluid transfer lines is an important part of using cryogenic systems such as those found in both ground and space based applications. The chilldown process is a complex combination of both thermal and fluid transient phenomena. A cryogenic liquid flows through a transfer line that is initially at a much higher temperature than the cryogen. Transient heat transfer processes between the liquid and transfer line cause vaporization of the liquid, and this phase change can cause transient pressure and flow surges in the liquid. As the transfer line is cooled, these effects diminish until the liquid reaches a steady flow condition in the chilled transfer line. If these transient phenomena are not properly accounted for in the design process of a cryogenic system, it can lead to damage or failure of system components during operation. For such cases, analytical modeling is desirable for ensuring that a cryogenic system transfer line design is adequate for handling the effects of a chilldown process. The purpose of this paper is to present the results of a numerical model developed using Generalized Fluid System Simulation Program (GFSSP)'s new fluid transient capability in combination with its previously developed thermal transient capability to predict pressure and flow surge in cryogenic transfer lines during a chilldown process. An experiment performed by the National Bureau of Standards (NBS) in 1966 has been chosen as the baseline comparison case for this work. NBS s experimental set-up consisted of a 10.59 cubic foot supply dewar, an inlet valve, and a 200 foot long, in Outside Diameter (OD) vacuum jacketed copper transfer line that exhausted to atmosphere. Three different inlet valves, an in-port ball valve, a 1-in-port globe valve and a 1-in-port gate valve, were used in NBS's experiments. Experiments were performed using both liquid hydrogen and liquid nitrogen as the fluids. The proposed paper will include detailed comparisons of GFSSP

Theoretical calculation of performance enhancement in lattice-matched SiGeSn/GeSn p-channel tunneling field-effect transistor with type-II staggered tunneling junction

NASA Astrophysics Data System (ADS)

Wang, Hongjuan; Han, Genquan; Wang, Yibo; Peng, Yue; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hu, Shengdong; Hao, Yue

2016-04-01

In this work, a lattice-matched SiGeSn/GeSn heterostructure p-channel tunneling field-effect transistor (hetero-PTFET) with a type-II staggered tunneling junction (TJ) is investigated theoretically. Lattice matching and type-II band alignment at the Γ-point is obtained at the SiGeSn/GeSn interface by tuning Sn and Si compositions. A steeper subthreshold swing (SS) and a higher on state current (I ON) are demonstrated in SiGeSn/GeSn hetero-PTFET than in GeSn homo-PTFET. Si0.31Ge0.49Sn0.20/Ge0.88Sn0.12 hetero-PTFET achieves a 2.3-fold higher I ON than Ge0.88Sn0.12 homo-PTFET at V DD of 0.3 V. Hetero-PTFET achieves a more abrupt hole profile and a higher carrier density near TJ than the homo-PTFET, which contributes to the significantly enhanced band-to-band tunneling (BTBT) rate and tunneling current in hetero-PTFET.

Advances in cryogenic engineering. Vols. 37A & 37B - Proceedings of the 1991 Cryogenic Engineering Conference, Univ. of Alabama, Huntsville, June 11-14, 1991

NASA Technical Reports Server (NTRS)

Fast, Ronald W. (Editor)

1991-01-01

The present volume on advances in cryogenic engineering discusses heat and mass transfer in helium, heat transfer in cryogenic fluids, thermoacoustic oscillations, and insulation. Attention is given to applications of superconductivity with reference to magnetic stability and coil protection, cryogenic techniques, and refrigeration for electronics and superconducting systems. Topics addressed include compressors, expanders, and pumps for liquid helium, magnetic refrigerators, pulse tube refrigerators, and cryocoolers. Also examined are properties of cryogenic fluids, cryogenic applications in transportion and space science and technology, and cryogenic instrumentation.

Preparation and performance of broadband antireflective sub-wavelength structures on Ge substrate

NASA Astrophysics Data System (ADS)

Shen, Xiang-Wei; Liu, Zheng-Tang; Li, Yang-Ping; Lu, Hong-Cheng; Xu, Qi-Yuan; Liu, Wen-Ting

2009-01-01

Sub-wavelength structures (SWS) were prepared on Ge substrates through photolithography and reactive ion etching (RIE) technology for broadband antireflective purposes in the long wave infrared (LWIR) waveband of 8-12 μm. Topography of the etched patterns was observed using high resolution optical microscope and atomic force microscope (AFM). Infrared transmission performance of the SWS was investigated by Fourier transform infrared (FTIR) spectrometer. Results show that the etched patterns were of high uniformity and fidelity, the SWS exhibited a good broadband antireflective performance with the increment of the average transmittance which is over 8-12 μm up to 8%.

CERN experience and strategy for the maintenance of cryogenic plants and distribution systems

NASA Astrophysics Data System (ADS)

Serio, L.; Bremer, J.; Claudet, S.; Delikaris, D.; Ferlin, G.; Pezzetti, M.; Pirotte, O.; Tavian, L.; Wagner, U.

2015-12-01

CERN operates and maintains the world largest cryogenic infrastructure ranging from ageing installations feeding detectors, test facilities and general services, to the state-of-the-art cryogenic system serving the flagship LHC machine complex. After several years of exploitation of a wide range of cryogenic installations and in particular following the last two years major shutdown to maintain and consolidate the LHC machine, we have analysed and reviewed the maintenance activities to implement an efficient and reliable exploitation of the installations. We report the results, statistics and lessons learned on the maintenance activities performed and in particular the required consolidations and major overhauling, the organization, management and methodologies implemented.

Cryogenic Thermal Management Advances during the CRYOTOOL Program

NASA Astrophysics Data System (ADS)

Bugby, D.; Stouffer, C.; Garzon, J.; Beres, M.; Gilchrist, A.; Roberts, T.; Davis, T.

2006-04-01

This paper describes the cryogenic thermal management advances made during the AFRL-sponsored CRYOTOOL program. Advances occurred as a result of conducting four technology development tasks: (1) development of a differential thermal expansion cryogenic thermal switch (DTE-CTSW) made with high purity Al end-pieces and an Ultem support rod; (2) carrying out of a dual DTE-CTSW/dual cryocooler performance test to quantify CTSW benefits in a redundant cryocooler system; (3) development of a miniaturized cryogenic loop heat pipe (mini-CLHP) that combines flex link, conduction bar, and CTSW functionalities; and (4) development of an across-gimbal cryogenic thermal transport system (GCTTS) with large diameter transport line coils for optics cooling. The results are as follows. The DTE-CTSW achieved an ON conductance of 2-3.6 W/K (from 35-90 K) and an OFF resistance of 1100-2300 K/W (300-230 K warm end). The redundant cryocooler test showed modest parasitic heat leak savings when dual DTE-CTSWs were used versus when they were not used. The mini-CLHP, using neon as the working fluid, transported 2.5 W at 35 K, achieved an OFF resistance of 1555 K/W, and had cross/axial flexibilities of 100-450 N/m. Lastly, GCTTS, using nitrogen as the working fluid, transported 20 W at 100 K in a flat configuration. Additional work is needed to verify GCTTS operation in an elevated orientation.

PIP-II Cryogenic System and the evolution of Superfluid Helium Cryogenic Plant Specifications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakravarty, Anindya; Rane, Tejas; Klebaner, Arkadiy

2017-07-06

The PIP-II cryogenic system consists of a Superfluid Helium Cryogenic Plant (SHCP) and a Cryogenic Distribution System (CDS) connecting the SHCP to the Superconducting (SC) Linac consisting of 25 cryomodules. The dynamic heat load of the SC cavities for continuous wave (CW) as well as pulsed mode of operation has been listed out. The static heat loads of the cavities along with the CDS have also been discussed. Simulation study has been carried out to compute the supercritical helium (SHe) flow requirements for each cryomodule. Comparison between the flow requirements of the cryomodules for the CW and pulsed modes ofmore » operation have also been made. From the total computed heat load and pressure drop values in the CDS, the basic specifications for the SHCP, required for cooling the SC Linac, have evolved.« less

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

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.

Conceptual design of ACB-CP for ITER cryogenic system

NASA Astrophysics Data System (ADS)

Jiang, Yongcheng; Xiong, Lianyou; Peng, Nan; Tang, Jiancheng; Liu, Liqiang; Zhang, Liang

2012-06-01

ACB-CP (Auxiliary Cold Box for Cryopumps) is used to supply the cryopumps system with necessary cryogen in ITER (International Thermonuclear Experimental Reactor) cryogenic distribution system. The conceptual design of ACB-CP contains thermo-hydraulic analysis, 3D structure design and strength checking. Through the thermohydraulic analysis, the main specifications of process valves, pressure safety valves, pipes, heat exchangers can be decided. During the 3D structure design process, vacuum requirement, adiabatic requirement, assembly constraints and maintenance requirement have been considered to arrange the pipes, valves and other components. The strength checking has been performed to crosscheck if the 3D design meets the strength requirements for the ACB-CP.

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

NASA Technical Reports Server (NTRS)

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

1985-01-01

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

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.

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.

Epitaxial Technologies for SiGeSn High Performance Optoelectronic Devices

DTIC Science & Technology

2015-04-29

comparison for specific detectivity (D*) between GeSn and other market dominating infrared detectors in short wavelength infrared range. An improved...Fig. 22(b). For this set of devices wherein the dark current is high, the shot noise dominates over other noise mechanisms. As applied voltage...interdigitated electrodes to allow high responsivity and low noise current. Photodiodes: The team has developed GeSn photodiode detector , which is a

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.

Thermographic Methods of Detecting Insulation Voids in Large Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Arens, Ellen; Nurge, Mark; Youngquist, Robert; Starr, Stanley

2010-01-01

Four very large (900Kgal) cryogenic liquid hydrogen and oxygen storage tanks at Kennedy Space Center's LC-39 launch pads were constructed in 1965 to support the Apollo/Saturn V Program and continue to support the Space Shuttle Program. These double-walled spherical tanks with powdered insulation in the annular region, have received minimal refurbishment or even inspection over the years. Intrusively inspecting these tanks would mean a significant down time to the program as the cryogenic liquid and the perlite insulation would have to be removed which would be a significant task and long-term schedule disruption. A study of the tanks was performed to determine the extent to which performance and structural information could be revealed without intrusive inspection. Thermal images of the tanks were taken over a variety of environmental conditions to determine the best conditions under which to compare and use thermography as a health monitoring technique as the tanks continue to age. The settling and subsequent compaction of insulation is a serious concern for cryogenic tanks. Comparison of images from the tanks reveals significant variations in the insulation in the annual regions and point to the use of thermography as a way to monitor for insulation migration and possible compaction. These measurements, when combined with mathematical models of historical boil-off data provide key insight to the condition of the vessels. Acceptance testing methods for new tanks, before they are filled with cryogenic commodity (and thereby thermally cycled), are needed and we explore how thermography can be used to accomplish this.

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.

Fermiology of Ce2 Rh3 Ge5

NASA Astrophysics Data System (ADS)

Wartenbe, Mark

The competition between localized and delocalized f electrons in heavy fermion materials produces a wide variety of interesting physical phenomena. Among these compounds is Ce2Rh3Ge5. This heavy-fermion system undergoes an antiferromagnetic transition below 4K and exhibits an angle dependent magnetic phase transition around 25 tesla. In addition, RF conductivity measurements in pulsed field (65T) have revealed quantum oscillations. Temperature dependence at fixed angle indicates relatively heavy effective masses of values ranging from ~3me on up to ~10me. This indicates that the narrow f-electron density of states is partially hybridized close to the Fermi energy, but also places strict cryogenic constraints upon the measurement (3Helium temperatures are required). Fermi surface calculations have produced complex figures which lend validation to such rich behavior. Presented are updated measurements including magnetization and revised theoretical calculations..

Technology Challenges for Deep-Throttle Cryogenic Engines for Space Exploration

NASA Technical Reports Server (NTRS)

Brown, Kendall K.; Nelson, Karl W.

2005-01-01

Historically, cryogenic rocket engines have not been used for in-space applications due to their additional complexity, the mission need for high reliability, and the challenges of propellant boil-off. While the mission and vehicle architectures are not yet defined for the lunar and Martian robotic and human exploration objectives, cryogenic rocket engines offer the potential for higher performance and greater architecture/mission flexibility. In-situ cryogenic propellant production could enable a more robust exploration program by significantly reducing the propellant mass delivered to low earth orbit, thus warranting the evaluation of cryogenic rocket engines versus the hypergolic bi-propellant engines used in the Apollo program. A multi-use engine. one which can provide the functionality that separate engines provided in the Apollo mission architecture, is desirable for lunar and Mars exploration missions because it increases overall architecture effectiveness through commonality and modularity. The engine requirement derivation process must address each unique mission application and each unique phase within each mission. The resulting requirements, such as thrust level, performance, packaging, bum duration, number of operations; required impulses for each trajectory phase; operation after extended space or surface exposure; availability for inspection and maintenance; throttle range for planetary descent, ascent, acceleration limits and many more must be addressed. Within engine system studies, the system and component technology, capability, and risks must be evaluated and a balance between the appropriate amount of technology-push and technology-pull must be addressed. This paper will summarize many of the key technology challenges associated with using high-performance cryogenic liquid propellant rocket engine systems and components in the exploration program architectures. The paper is divided into two areas. The first area describes how the mission

Technology Challenges for Deep-Throttle Cryogenic Engines for Space Exploration

NASA Astrophysics Data System (ADS)

Brown, Kendall K.; Nelson, Karl W.

2005-02-01

Historically, cryogenic rocket engines have not been used for in-space applications due to their additional complexity, the mission need for high reliability, and the challenges of propellant boil-off. While the mission and vehicle architectures are not yet defined for the lunar and Martian robotic and human exploration objectives, cryogenic rocket engines offer the potential for higher performance and greater architecture/mission flexibility. In-situ cryogenic propellant production could enable a more robust exploration program by significantly reducing the propellant mass delivered to low earth orbit, thus warranting the evaluation of cryogenic rocket engines versus the hypergolic bipropellant engines used in the Apollo program. A multi-use engine, one which can provide the functionality that separate engines provided in the Apollo mission architecture, is desirable for lunar and Mars exploration missions because it increases overall architecture effectiveness through commonality and modularity. The engine requirement derivation process must address each unique mission application and each unique phase within each mission. The resulting requirements, such as thrust level, performance, packaging, burn duration, number of operations; required impulses for each trajectory phase; operation after extended space or surface exposure; availability for inspection and maintenance; throttle range for planetary descent, ascent, acceleration limits and many more must be addressed. Within engine system studies, the system and component technology, capability, and risks must be evaluated and a balance between the appropriate amount of technology-push and technology-pull must be addressed. This paper will summarize many of the key technology challenges associated with using high-performance cryogenic liquid propellant rocket engine systems and components in the exploration program architectures. The paper is divided into two areas. The first area describes how the mission

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

Cryogenic Volume-Phase Holographic Grisms for MOIRCS

NASA Astrophysics Data System (ADS)

Ebizuka, Noboru; Ichiyama, Kotaro; Yamada, Toru; Tokoku, Chihiro; Onodera, Masato; Hanesaka, Mai; Kodate, Kashiko; Katsuno Uchimoto, Yuka; Maruyama, Miyoko; Shimasaku, Kazuhiro; Tanaka, Ichi; Yoshikawa, Tomohiro; Kashikawa, Nobunari; Iye, Masanori; Ichikawa, Takashi

2011-03-01

We have developed high-dispersion VPH (volume phase holographic) grisms with zinc selenide (ZnSe) prisms for the cryogenic optical system of MOIRCS (Multi-Object near-InfraRed Camera and Spectrograph) for Y-, J-, H-, and K-band observations. We fabricated VPH gratings using a hologram resin. After several heat cycles at between room temperature and 120 K, the VPH gratings were assembled to grisms by gluing with two ZnSe prisms. Several heat cycles were also carried out for the grisms before being installed into MOIRCS. We measured the efficiencies of the VPH grisms in a laboratory, and found them to be 70%-82%. The performances obtained by observations of MOIRCS with the 8.2 m Subaru Telescope have been found to be very consistent with the results in the laboratory test. This is the first astronomical application of cryogenic VPH grisms.

Using Cryogenics to Improve the Efficiency of Photovoltaic Solar Cells

NASA Astrophysics Data System (ADS)

Somers, Hunter; Martinez, Estefano; Ganley, Grace; Rivera, Daniel; Hopp, Aric; Jakachira, Takunda; West, Andrea; Sapp, Whitley; Watson, Casey R.; Paulin, Pete

Improving the reliability and profitability of green energy sources plays a crucial part in transitioning away from fossil fuels as an energy source. As a possible means of making solar energy production more efficient, we consider the effects of cryogenically treating photovoltaic (PV) solar panels at 300 Below, Inc. We report on the pre- and post-cryo performance of two different types of solar panels, when they are exposed to the same, artificial light source. Then, using NREL data, we project the financial benefits of adopting cryogenically treated solar panels throughout the United States over the next five years. 300 Below Inc.

49 CFR 173.316 - Cryogenic liquids in cylinders.

Code of Federal Regulations, 2010 CFR

2010-10-01

... °F.). (2) The cryogenic liquids of argon, nitrogen, oxygen, helium and neon must be loaded and... 49 Transportation 2 2010-10-01 2010-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in...

49 CFR 173.316 - Cryogenic liquids in cylinders.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 2 2013-10-01 2013-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than...

49 CFR 173.316 - Cryogenic liquids in cylinders.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in cylinders. (a) General requirements. (1) A cylinder may not be loaded with a cryogenic liquid colder than...

Spray-On Foam Insulations for Launch Vehicle Cryogenic Tanks

NASA Technical Reports Server (NTRS)

Fesmire, J. E.; Cofman, B. E.; Menghelli, B. J.; Heckle, K. W.

2011-01-01

Spray-on foam insulation (SOFI) has been developed for use on the cryogenic tanks of space launch vehicles beginning in the 1960s with the Apollo program. The use of SOFI was further developed for the Space Shuttle program. The External Tank (ET) of the Space Shuttle, consisting of a forward liquid oxygen tank in line with an aft liquid hydrogen tank, requires thermal insulation over its outer surface to prevent ice formation and avoid in-flight damage to the ceramic tile thermal protection system on the adjacent Orbiter. The insulation also provides system control and stability with throughout the lengthy process of cooldown, loading, and replenishing the tank. There are two main types of SOFI used on the ET: acreage (with the rind) and closeout (machined surface). The thermal performance of the seemingly simple SOFI system is a complex of many variables starting with the large temperature difference of from 200 to 260 K through the typical 25-mm thickness. Environmental factors include air temperature and humidity, wind speed, solar exposure, and aging or weathering history. Additional factors include manufacturing details, launch processing operations, and number of cryogenic thermal cycles. The study of the cryogenic thermal performance of SOFI under large temperature differentials is the subject of this article. The amount of moisture taken into the foam during the cold soak phase, termed Cryogenic Moisture Uptake, must also be considered. The heat leakage rates through these foams were measured under representative conditions using laboratory standard liquid nitrogen boiloff apparatus. Test articles included baseline, aged, and weathered specimens. Testing was performed over the entire pressure range from high vacuum to ambient pressure. Values for apparent thermal conductivity and heat flux were calculated and compared with prior data. As the prior data of record was obtained for small temperature differentials on non-weathered foams, analysis of the

Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks

NASA Technical Reports Server (NTRS)

Lopez, Alfredo; Grayson, Gary D.; Chandler, Frank O.; Hastings, Leon J.; Heyadat, Ali

2007-01-01

A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in normal gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-31) software. Quantitative model validation is ,provided by engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage_ Technology Demonstrator (STUSTD) program. The engineering checkout tests provide cryogenic tank self-pressurization test data at various heat leaks and tank fill levels. The predicted self-pressurization rates, ullage and liquid temperatures at discrete locations within the STUSTD tank are in good agreement with test data. The work presented here advances current CFD modeling capabilities for cryogenic pressure control and helps develop a low cost CFD-based design process for space hardware.

Investigation of two and three parameter equations of state for cryogenic fluids

NASA Technical Reports Server (NTRS)

Jenkins, Susan L.; Majumdar, Alok K.; Hendricks, Robert C.

1990-01-01

Two-phase flows are a common occurrence in cryogenic engines and an accurate evaluation of the heat-transfer coefficient in two-phase flow is of significant importance in their analysis and design. The thermodynamic equation of state plays a key role in calculating the heat transfer coefficient which is a function of thermodynamic and thermophysical properties. An investigation has been performed to study the performance of two- and three-parameter equations of state to calculate the compressibility factor of cryogenic fluids along the saturation loci. The two-parameter equations considered here are van der Waals and Redlich-Kwong equations of state. The three-parameter equation represented here is the generalized Benedict-Webb-Rubin (BWR) equation of Lee and Kesler. Results have been compared with the modified BWR equation of Bender and the extended BWR equations of Stewart. Seven cryogenic fluids have been tested; oxygen, hydrogen, helium, nitrogen, argon, neon, and air. The performance of the generalized BWR equation is poor for hydrogen and helium. The van der Waals equation is found to be inaccurate for air near the critical point. For helium, all three equations of state become inaccurate near the critical point.

Gamma and x-ray irradiation effects on different Ge and Ge/F doped optical fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alessi, A., E-mail: antonino.alessi@univ-st-etienne.fr; Girard, S.; Di Francesca, D.

2015-08-28

We performed electron paramagnetic resonance (EPR) measurements on γ and X ray irradiated Ge doped and Ge/F co-doped optical fibers. We considered three different drawing conditions (speed and tension), and for each type of drawing, we studied Ge and Ge/F doped samples having Ge doping level above 4% by weight. The EPR data recorded for the γ ray irradiated fibers confirm that all the samples exhibit a very close radiation response regardless of the drawing conditions corresponding to values used for the production of specialty fibers. Furthermore, as for the X irradiated materials, in the γ ray irradiated F co-dopedmore » fibers, we observed that the Ge(1) and the Ge(2) defects generation is unchanged, whereas it was enhanced for the E'Ge. In the various fibers, the comparison of the γ and X-ray induced concentrations of these kinds of Ge related defects indicates that the two irradiations induce similar effects regardless of the different employed dose rates and sources. Confocal microscopy luminescence results show that the starting content of the Germanium Lone Pair Center (GLPC) is neither strongly affected by the Ge content nor by the drawing conditions, and we consider the similarity of the GLPC content as key factor in determining many of the above reported similarities.« less

Insight into unusual impurity absorbability of GeO(2) in GeO(2)∕Ge stacks.

PubMed

Ogawa, Shingo; Suda, Taichi; Yamamoto, Takashi; Kutsuki, Katsuhiro; Hideshima, Iori; Hosoi, Takuji; Shimura, Takayoshi; Watanabe, Heiji

2011-10-03

Adsorbed species and its diffusion behaviors in GeO(2)∕Ge stacks, which are future alternative metal-oxide-semiconductor (MOS) materials, have been investigated using various physical analyses. We clarified that GeO(2) rapidly absorbs moisture in air just after its exposure. After the absorbed moisture in GeO(2) reaches a certain limit, the GeO(2) starts to absorb some organic molecules, which is accompanied by a structural change in GeO(2) to form a partial carbonate or hydroxide. We also found that the hydrogen distribution in GeO(2) shows intrinsic characteristics, indicative of different diffusion behaviors at the surface and at the GeO(2)∕Ge interface. Because the impurity absorbability of GeO(2) has a great influence on the electrical properties in Ge-MOS devices, these results provide valuable information in realizing high quality GeO(2)∕Ge stacks for the actual use of Ge-MOS technologies.

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown.

PubMed

Darr, Samuel; Dong, Jun; Glikin, Neil; Hartwig, Jason; Majumdar, Alok; Leclair, Andre; Chung, Jacob

2016-01-01

Manned deep space exploration will require cryogenic in-space propulsion. Yet, accurate prediction of cryogenic pipe flow boiling heat transfer is lacking, due to the absence of a cohesive reduced gravity data set covering the expected flow and thermodynamic parameter ranges needed to validate cryogenic two-phase heat transfer models. This work provides a wide range of cryogenic chilldown data aboard an aircraft flying parabolic trajectories to simulate reduced gravity. Liquid nitrogen is used to quench a 1.27 cm diameter tube from room temperature. The pressure, temperature, flow rate, and inlet conditions are reported from 10 tests covering liquid Reynolds number from 2,000 to 80,000 and pressures from 80 to 810 kPa. Corresponding terrestrial gravity tests were performed in upward, downward, and horizontal flow configurations to identify gravity and flow direction effects on chilldown. Film boiling heat transfer was lessened by up to 25% in reduced gravity, resulting in longer time and more liquid to quench the pipe to liquid temperatures. Heat transfer was enhanced by increasing the flow rate, and differences between reduced and terrestrial gravity diminished at high flow rates. The new data set will enable the development of accurate and robust heat transfer models of cryogenic pipe chilldown in reduced gravity.

Operational present status and reliability analysis of the upgraded EAST cryogenic system

NASA Astrophysics Data System (ADS)

Zhou, Z. W.; Y Zhang, Q.; Lu, X. F.; Hu, L. B.; Zhu, P.

2017-12-01

Since the first commissioning in 2005, the cryogenic system for EAST (Experimental Advanced Superconducting Tokamak) has been cooled down and warmed up for thirteen experimental campaigns. In order to promote the refrigeration efficiencies and reliability, the EAST cryogenic system was upgraded gradually with new helium screw compressors and new dynamic gas bearing helium turbine expanders with eddy current brake to improve the original poor mechanical and operational performance from 2012 to 2015. Then the totally upgraded cryogenic system was put into operation in the eleventh cool-down experiment, and has been operated for the latest several experimental campaigns. The upgraded system has successfully coped with various normal operational modes during cool-down and 4.5 K steady-state operation under pulsed heat load from the tokamak as well as the abnormal fault modes including turbines protection stop. In this paper, the upgraded EAST cryogenic system including its functional analysis and new cryogenic control networks will be presented in detail. Also, its operational present status in the latest cool-down experiments will be presented and the system reliability will be analyzed, which shows a high reliability and low fault rate after upgrade. In the end, some future necessary work to meet the higher reliability requirement for future uninterrupted long-term experimental operation will also be proposed.

The effect of reduced gravity on cryogenic nitrogen boiling and pipe chilldown

PubMed Central

Darr, Samuel; Dong, Jun; Glikin, Neil; Hartwig, Jason; Majumdar, Alok; Leclair, Andre; Chung, Jacob

2016-01-01

Manned deep space exploration will require cryogenic in-space propulsion. Yet, accurate prediction of cryogenic pipe flow boiling heat transfer is lacking, due to the absence of a cohesive reduced gravity data set covering the expected flow and thermodynamic parameter ranges needed to validate cryogenic two-phase heat transfer models. This work provides a wide range of cryogenic chilldown data aboard an aircraft flying parabolic trajectories to simulate reduced gravity. Liquid nitrogen is used to quench a 1.27 cm diameter tube from room temperature. The pressure, temperature, flow rate, and inlet conditions are reported from 10 tests covering liquid Reynolds number from 2,000 to 80,000 and pressures from 80 to 810 kPa. Corresponding terrestrial gravity tests were performed in upward, downward, and horizontal flow configurations to identify gravity and flow direction effects on chilldown. Film boiling heat transfer was lessened by up to 25% in reduced gravity, resulting in longer time and more liquid to quench the pipe to liquid temperatures. Heat transfer was enhanced by increasing the flow rate, and differences between reduced and terrestrial gravity diminished at high flow rates. The new data set will enable the development of accurate and robust heat transfer models of cryogenic pipe chilldown in reduced gravity. PMID:28725740

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.

Cryogenic Target-Implosion Experiments on OMEGA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harding, D.R.; Meyerhofer, D.D.; Sangster, T.C.

The University of Rochester’s Laboratory for Laser Energetics has been imploding thick cryogenic targets for six years. Improvements in the Cryogenic Target Handling System and the ability to accurately design laser pulse shapes that properly time shocks and minimize electron preheat, produced high fuel areal densities in deuterium cryogenic targets (202+/-7 mg/cm^2). The areal density was inferred from the energy loss of secondary protons in the fuel (D2) shell. Targets were driven on a low final adiabat (alpha = 2) employing techniques to radially grade the adiabat (the highest adiabat at the ablation surface). The ice layer meets the target-designmore » toughness specification for DT ice of 1-um rms (all modes), while D2 ice layers average 3.0-um-rms roughness. The implosion experiments and the improvements in the quality and understanding of cryogenic targets are presented.« less

49 CFR 173.316 - Cryogenic liquids in cylinders.

Code of Federal Regulations, 2011 CFR

2011-10-01

... filling density for hydrogen, cryogenic liquid is defined as the percent ratio of the weight of lading in... 49 Transportation 2 2011-10-01 2011-10-01 false Cryogenic liquids in cylinders. 173.316 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Gases; Preparation and Packaging § 173.316 Cryogenic liquids in...

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

NASA Astrophysics Data System (ADS)

Fast, R. W.

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. For individual items see A83-43221 to A83-43250

The COLD-SAT Experiment for Cryogenic Fluid Management Technology

NASA Technical Reports Server (NTRS)

Schuster, J. R.; Wachter, J. P.; Vento, D. M.

1990-01-01

Future national space transportation missions will depend on the use of cryogenic fluid management technology development needs for these missions. In-space testing will be conducted in order to show low gravity cryogenic fluid management concepts and to acquire a technical data base. Liquid H2 is the preferred test fluid due to its propellant use. The design of COLD-SAT (Cryogenic On-orbit Liquid Depot Storage, Acquisition, and Transfer Satellite), an Expendable Launch Vehicle (ELV) launched orbital spacecraft that will perform subcritical liquid H2 storage and transfer experiments under low gravity conditions is studied. An Atlas launch vehicle will place COLD-SAT into a circular orbit, and the 3-axis controlled spacecraft bus will provide electric power, experiment control, and data management, attitude control, and propulsive accelerations for the experiments. Low levels of acceleration will provide data on the effects that low gravity might have on the heat and mass transfer processes used. The experiment module will contain 3 liquid H2 tanks; fluid transfer, pressurization and venting equipment; and instrumentation.

Cryogenic wind tunnels: Unique capabilities for the aerodynamicist

NASA Technical Reports Server (NTRS)

Hall, R. M.

1976-01-01

The cryogenic wind-tunnel concept as a practical means for improving ground simulation of transonic flight conditions. The Langley 1/3-meter transonic cryogenic tunnel is operational, and the design of a cryogenic National Transonic Facility is undertaken. A review of some of the unique capabilities of cryogenic wind tunnels is presented. In particular, the advantages of having independent control of tunnel Mach number, total pressure, and total temperature are highlighted. This separate control over the three tunnel parameters will open new frontiers in Mach number, Reynolds number, aeroelastic, and model-tunnel interaction studies.

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.

Development of a cryogenic DC-low noise amplifier for SQuID-based readout electronics

NASA Astrophysics Data System (ADS)

Macculi, C.; Torrioli, G.; Di Giorgio, A.; Spinoglio, L.; Piro, Luigi

2014-07-01

We present the preliminary results of the design and test activities for a DC cryogenic low noise amplifier for the SAFARI imaging spectrometer, planned to be onboard the SPICA mission, necessary not only to drive, as usual, the voltage signal produced by the SQuID but also to boost such signals over about 7 meter of path towards the warm feedback electronics. This development has been done in the framework of the mission preparation studies, within the European Consortium for the development of the SAFARI instrument. The actual configuration of the SAFARI focal plane assembly (FPA), indeed, foresees a long distance to the warm back end electronics. It is therefore mandatory to boost the faint electric signal coming from the SQuID device by keeping under control both power dissipation and noise: this is the main role of the designed Cryogenic Low Noise Amplifier (LNA). Working at 136K, it has a differential input gain-stage, and a differential balanced voltage buffer output stage, running at few mW target overall power. At present the design is based on the use of Heterojunction Si:Ge transistors, the required bandwidth is DC-4MHz and the required noise lower than 1 nV/rtHz.

A cryogen-free variable temperature scanning tunneling microscope capable for inelastic electron tunneling spectroscopy

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Huang, Di; Wu, Shiwei

While low temperature scanning tunneling microscope (STM) has become an indispensable research tool in surface science, its versatility is yet limited by the shortage or high cost of liquid helium. The makeshifts include the use of alternative cryogen (such as liquid nitrogen) at higher temperature or the development of helium liquefier system usually at departmental or campus wide. The ultimate solution would be the direct integration of a cryogen-free cryocooler based on GM or pulse tube closed cycle in the STM itself. However, the nasty mechanical vibration at low frequency intrinsic to cryocoolers has set the biggest obstacle because of the known challenges in vibration isolation required to high performance of STM. In this talk, we will present the design and performance of our home-built cryogen-free variable temperature STM at Fudan University. This system can obtain atomically sharp STM images and high resolution dI/dV spectra comparable to state-of-the-art low temperature STMs, but with no limitation on running hours. Moreover, we demonstrated the inelastic tunneling spectroscopy (STM-IETS) on a single CO molecule with a cryogen-free STM for the first time.

Advanced Devices for Cryogenic Thermal Management

NASA Astrophysics Data System (ADS)

Bugby, D.; Stouffer, C.; Garzon, J.; Beres, M.; Gilchrist, A.

2006-04-01

This paper describes six advanced cryogenic thermal management devices/subsystems developed by Swales Aerospace for ground/space-based applications of interest to NASA, DoD, and the commercial sector. The devices/subsystems described herein include the following: (a) a differential thermal expansion cryogenic thermal switch (DTE-CTSW) constructed with high purity aluminum end-pieces and an Ultem support rod for the 6 K Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope (JWST) (b) a quad-redundant DTE-CTSW assembly for the 35 K science instruments (NIRCam, NIRSpec, and FGS) mounted on the JWST Integrated Science Instrument Module (ISIM) (c) a cryogenic diode heat pipe (CDHP) thermal switching system using methane as the working fluid for the 100 K CRISM hyperspectral mapping instrument on the Mars Reconnaissance Orbiter (MRO) and (d) three additional devices/subsystems developed during the AFRL-sponsored CRYOTOOL program, which include a dual DTE-CTSW/dual cryocooler test bed, a miniaturized neon cryogenic loop heat pipe (mini-CLHP), and an across gimbal cryogenic thermal transport system (GCTTS). For the first three devices/subsystems mentioned above, this paper describes key aspects of the development efforts including concept definition, design, fabrication, and testing. For the latter three, this paper provides brief overview descriptions as key details are provided in a related paper.

Study on a neon cryogenic oscillating heat pipe with long heat transport distance

NASA Astrophysics Data System (ADS)

Liang, Qing; Li, Yi; Wang, Qiuliang

2018-06-01

An experimental study is carried out to study the heat transfer characteristics of a cryogenic oscillating heat pipe (OHP) with long heat transport distance. The OHP is made up of a capillary tube with an inner diameter of 1.0 mm and an outer diameter of 2.0 mm. The working fluid is neon, and the length of the adiabatic section is 480 mm. Tests are performed with the different heat inputs, liquid filling ratios and condenser temperature. For the cryogenic OHP with a liquid filling ratio of 30.7% at the condenser temperature of 28 K, the effective thermal conductivity is 3466-30,854 W/m K, and the maximum transfer power is 35.60 W. With the increment of the heat input, the effective thermal conductivity of the cryogenic OHP increases at the liquid filling ratios of 30.7% and 38.5%, while it first increases and then decreases at the liquid filling ratios of 15.2% and 23.3%. Moreover, the effective thermal conductivity increases with decreasing liquid filling ratio at the small heat input, and the maximum transfer power first increases and then decreases with increasing liquid filling ratio. Finally, it is found that the thermal performance of the cryogenic OHP can be improved by increasing the condenser temperature.

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

Cryogenic refractive index of Heraeus homosil glass

NASA Astrophysics Data System (ADS)

Miller, Kevin H.; Quijada, Manuel A.; Leviton, Douglas B.

2017-08-01

This paper reports measurements of the refractive index of Homosil (Heraeus) over the wavelength range of 0.34—3.16 μm and temperature range of 120—335 K. These measurements were performed by using the Cryogenic High Accuracy Refraction Measuring System (CHARMS) facility at the NASA's Goddard Space Flight Center. These measurements were in support of an integrated Structural-Thermal-Optical-Performance (STOP) model that was developed for a fieldwidened Michelson interferometer that is being built and tested for the High Spectral Resolution Lidar (HSRL) project at the NASA Langley Research Center (LaRC). The cryogenic refractive index measurements were required in order to account for the highly sensitive performance of the HSRL instrument to changes in refractive index with temperature, temperature gradients, thermal expansion, and deformation due to mounting stresses. A dense coverage of the absolute refractive index over the aforementioned wavelength and temperature ranges was used to determine the thermo-optic coefficient (dn/dT) and dispersion relation (dn/dλ) as a function of wavelength and temperature. Our measurements of Homosil will be compared with measurements of other glasses from the fused silica family studied in CHARMS as well as measurements reported elsewhere in the literature.

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.

SiGe epitaxial memory for neuromorphic computing with reproducible high performance based on engineered dislocations

NASA Astrophysics Data System (ADS)

Choi, Shinhyun; Tan, Scott H.; Li, Zefan; Kim, Yunjo; Choi, Chanyeol; Chen, Pai-Yu; Yeon, Hanwool; Yu, Shimeng; Kim, Jeehwan

2018-01-01

Although several types of architecture combining memory cells and transistors have been used to demonstrate artificial synaptic arrays, they usually present limited scalability and high power consumption. Transistor-free analog switching devices may overcome these limitations, yet the typical switching process they rely on—formation of filaments in an amorphous medium—is not easily controlled and hence hampers the spatial and temporal reproducibility of the performance. Here, we demonstrate analog resistive switching devices that possess desired characteristics for neuromorphic computing networks with minimal performance variations using a single-crystalline SiGe layer epitaxially grown on Si as a switching medium. Such epitaxial random access memories utilize threading dislocations in SiGe to confine metal filaments in a defined, one-dimensional channel. This confinement results in drastically enhanced switching uniformity and long retention/high endurance with a high analog on/off ratio. Simulations using the MNIST handwritten recognition data set prove that epitaxial random access memories can operate with an online learning accuracy of 95.1%.

Cryogenic optical testing results of JWST aspheric test plate lens

NASA Astrophysics Data System (ADS)

Smith, Koby Z.; Towell, Timothy C.

2011-09-01

The James Webb Space Telescope (JWST) Secondary Mirror Assembly (SMA) is a circular 740mm diameter beryllium convex hyperboloid that has a 23.5nm-RMS (λ/27 RMS) on-orbit surface figure error requirement. The radius of curvature of the SMA is 1778.913mm+/-0.45mm and has a conic constant of -1.6598+/-0.0005. The on-orbit operating temperature of the JWST SMA is 22.5K. Ball Aerospace & Technologies Corp. (BATC) is under contract to Northrop Grumman Aerospace Systems (NGAS) to fabricate, assemble, and test the JWST SMA to its on-orbit requirements including the optical testing of the SMA at its cryogenic operating temperature. BATC has fabricated and tested an Aspheric Test Plate Lens (ATPL) that is an 870mm diameter fused silica lens used as the Fizeau optical reference in the ambient and cryogenic optical testing of the JWST Secondary Mirror Assembly (SMA). As the optical reference for the SMA optical test, the concave optical surface of the ATPL is required to be verified at the same 20K temperature range required for the SMA. In order to meet this objective, a state-of-the-art helium cryogenic testing facility was developed to support the optical testing requirements of a number of the JWST optical testing needs, including the ATPL and SMA. With the implementation of this cryogenic testing facility, the ATPL was successfully cryogenically tested and performed to less than 10nm-RMS (λ/63 RMS) surface figure uncertainty levels for proper reference backout during the SMA optical testing program.

Cryogenics for LDR

NASA Technical Reports Server (NTRS)

Kittel, Peter

1988-01-01

Three cryogenic questions of importance to Large Deployable Reflector (LDR) are discussed: the primary cooling requirement, the secondary cooling requirement, and the instrument changeout requirement.

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

Three-dimensional analysis for liquid hydrogen in a cryogenic storage tank with heat pipe pump system

NASA Astrophysics Data System (ADS)

Ho, Son H.; Rahman, Muhammad M.

2008-01-01

This paper presents a study on fluid flow and heat transfer of liquid hydrogen in a zero boil-off cryogenic storage tank in a microgravity environment. The storage tank is equipped with an active cooling system consisting of a heat pipe and a pump-nozzle unit. The pump collects cryogen at its inlet and discharges it through its nozzle onto the evaporator section of the heat pipe in order to prevent the cryogen from boiling off due to the heat leaking through the tank wall from the surroundings. A three-dimensional (3-D) finite element model is employed in a set of numerical simulations to solve for velocity and temperature fields of liquid hydrogen in steady state. Complex structures of 3-D velocity and temperature distributions determined from the model are presented. Simulations with an axisymmetric model were also performed for comparison. Parametric study results from both models predict that as the speed of the cryogenic fluid discharged from the nozzle increases, the mean or bulk cryogenic fluid speed increases linearly and the maximum temperature within the cryogenic fluid decreases.

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.

Shuttle cryogenic supply system optimization study. Volume 2: Technical report, sections 4 through 9

NASA Technical Reports Server (NTRS)

1973-01-01

The design and development of cryogenic supply systems for space shuttle vehicles are discussed. The weights, component counts, and statements of advantages and disadvantages of the systems considered are presented. Performance characteristics of the systems are analyzed in the form of graphs. Block diagrams and engineering drawings of the candidate systems are provided. Special consideration is given to flow rates and thermodynamic properties of the cryogenic systems.

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.

Stressed and unstressed Ge:Ga detector arrays for airborne astronomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stacey, G.J.; Beeman, J.W.; Haller, E.E.

1992-11-01

We have constructed and used two dimensional arrays of both unstressed and stressed Ge:GA photoconductive detectors for far-infrared astronomy from the Kuiper Airborne Observatory (KAO). The 25 element (5 x 5) arrays are designed for a new cryogenically cooled spectrometer, the MPE/UCB Far-Infrared Imaging Fabry-Perot Interferometer (FIFI). All of the pixels for the stressed array performed well on the first flights with FIFI; 25% of the detectors in the array are more sensitive than our best single element detector, with background limited noise equivalent powers (NEPs) [approx lt] 3.0 [times] 10[sup [minus]15] W Hz[sup [minus]1/2] at 158 [mu]m and 40more » km s[sup [minus]1] spectral resolution. The average array element performs within [plus minus] 15% of this value. With a bias field of 0.1 V/cm, the average detector response is 20 [plus minus] 6 Amp/Watt at 158 [mu]m. The cutoff wavelength and response also compare well with our single element detectors. The unstressed array delivers significantly better performance than our single element detector due to the lower thermal background in the new spectrometer. The average background limited NEP at 88 [mu]m and 35 km s[sup [minus]1] spectral resolution is approx. 7 [times] 10[sup [minus]15] W Hz[sup [minus]1/2]. 18 refs., 10 figs., 2 tabs.« less

Ge/graded-SiGe multiplication layers for low-voltage and low-noise Ge avalanche photodiodes on Si

NASA Astrophysics Data System (ADS)

Miyasaka, Yuji; Hiraki, Tatsurou; Okazaki, Kota; Takeda, Kotaro; Tsuchizawa, Tai; Yamada, Koji; Wada, Kazumi; Ishikawa, Yasuhiko

2016-04-01

A new structure is examined for low-voltage and low-noise Ge-based avalanche photodiodes (APDs) on Si, where a Ge/graded-SiGe heterostructure is used as the multiplication layer of a separate-absorption-carrier-multiplication structure. The Ge/SiGe heterojunction multiplication layer is theoretically shown to be useful for preferentially enhancing impact ionization for photogenerated holes injected from the Ge optical-absorption layer via the graded SiGe, reflecting the valence band discontinuity at the Ge/SiGe interface. This property is effective not only for the reduction of operation voltage/electric field strength in Ge-based APDs but also for the reduction of excess noise resulting from the ratio of the ionization coefficients between electrons and holes being far from unity. Such Ge/graded-SiGe heterostructures are successfully fabricated by ultrahigh-vacuum chemical vapor deposition. Preliminary pin diodes having a Ge/graded-SiGe multiplication layer act reasonably as photodetectors, showing a multiplication gain larger than those for diodes without the Ge/SiGe heterojunction.

Application of JLab 12GeV helium refrigeration system for the FRIB accelerator at MSU

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganni, Venkatarao; Knudsen, Peter N.; Arenius, Dana M.

The planned approach to have a turnkey helium refrigeration system for the MSU-FRIB accelerator system, encompassing the design, fabrication, installation and commissioning of the 4.5-K refrigerator cold box(es), cold compression system, warm compression system, gas management, oil removal and utility/ancillary systems, was found to be cost prohibitive. Following JLab’s suggestion, MSU-FRIB accelerator management made a formal request to evaluate the applicability of the recently designed 12GeV JLab cryogenic system for this application. The following paper will outline the findings and the planned approach for the FRIB helium refrigeration system.

Li3Ge3Se6: the first ternary lithium germanium selenide with interesting ∞[Ge6Se12]n chains constructed by ethane-like [Ge2Se6]6- clusters.

PubMed

Li, Guangmao; Zhen, Ni; Chu, Yu; Zhou, Zhongxiang

2017-12-21

Li 3 Ge 3 Se 6 , the first compound of the ternary Li/Ge/Se system, has been synthesized. Note that interesting 1D ∞ [Ge 6 Se 12 ] n chains constructed by ethane-like [Ge 2 Se 6 ] 6- clusters were discovered in its structure. Investigations on the structures of all the [Ge 2 Se 6 ] 6- cluster-containing compounds have shown that only in Li 3 Ge 3 Se 6 are there 1D chains composed of [Ge 2 Se 6 ] 6- clusters, which result from the space limitation within the tunnels surrounded by LiSe 6 octahedra. Raman spectrum was obtained to demonstrate the existence of Ge-Ge bonds. UV-visible-NIR diffuse reflection spectrum showed an optical bandgap of 2.08 eV. Theoretical calculations based on first principles have also been performed for its band structure and density of states to analyze its structure-property relationship.

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.

Shuttle cryogenic supply system optimization study. Volume 3: Technical report, section 10, 11 and 12

NASA Technical Reports Server (NTRS)

1973-01-01

The evaluation of candidate cryogenic fuel systems for space shuttle vehicles is discussed. A set of guidelines was used to establish a matrix of possible combinations for the integration of potential cryogenic systems. The various concepts and combinations which resulted from the integration efforts are described. The parameters which were considered in developing the matrix are: (1) storage of cryogenic materials, (2) fuel lines, (3) tank pressure control, (4) thermal control, (5) fluid control, and (6) fluid conditioning. Block diagrams and drawings of the candidate systems are provided. Performance predictions for the systems are outlined in tables of data.

Propulsion Risk Reduction Activities for Nontoxic Cryogenic Propulsion

NASA Technical Reports Server (NTRS)

Smith, Timothy D.; Klem, Mark D.; Fisher, Kenneth L.

2010-01-01

The Propulsion and Cryogenics Advanced Development (PCAD) Project s primary objective is to develop propulsion system technologies for nontoxic or "green" propellants. The PCAD project focuses on the development of nontoxic propulsion technologies needed to provide necessary data and relevant experience to support informed decisions on implementation of nontoxic propellants for space missions. Implementation of nontoxic propellants in high performance propulsion systems offers NASA an opportunity to consider other options than current hypergolic propellants. The PCAD Project is emphasizing technology efforts in reaction control system (RCS) thruster designs, ascent main engines (AME), and descent main engines (DME). PCAD has a series of tasks and contracts to conduct risk reduction and/or retirement activities to demonstrate that nontoxic cryogenic propellants can be a feasible option for space missions. Work has focused on 1) reducing the risk of liquid oxygen/liquid methane ignition, demonstrating the key enabling technologies, and validating performance levels for reaction control engines for use on descent and ascent stages; 2) demonstrating the key enabling technologies and validating performance levels for liquid oxygen/liquid methane ascent engines; and 3) demonstrating the key enabling technologies and validating performance levels for deep throttling liquid oxygen/liquid hydrogen descent engines. The progress of these risk reduction and/or retirement activities will be presented.

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.

Results of an Advanced Development Zero Boil-Off Cryogenic Propellant Storage Test

NASA Technical Reports Server (NTRS)

Plachta, David

2004-01-01

A zero boil-off (ZBO) cryogenic propellant storage concept was recently tested in a thermally relevant low-earth orbit environment, an important development in the effort to apply this concept to flight projects. Previous efforts documented the benefits of ZBO for launch vehicle upper stages in a low-earth orbit (LEO). Central to that analysis is a ZBO Cryogenic Analysis Tool that estimates the performance of each component and the ZBO system. This test is essential to the validation of that tool, and was the first flight representative configuration tested in a thermally representative environment. The test article was comprised of a spherical 1.4 m diameter insulated propellant tank, with a submerged mixer, a cryogenic heat pipe, flight design cryocooler, and a radiator. All were enclosed in a thermal shroud and inserted into and tested in a vacuum chamber that simulated an LEO thermal environment. Thermal and pressure control tests were performed at sub-critical LN2 temperatures and approximately 2 atmospheres pressure. The cold side of the ZBO system performed well. In particular, the heat pipe performed better than expected, which suggests that the cryocooler could be located further from the tank than anticipated, i.e. on a spacecraft bus, while maintaining the desired efficiency. Also, the mixer added less heat than expected. The tank heating rate through the insulation was higher than expected; also the temperatures on the cryocooler hot side were higher than planned. This precluded the cryocooler from eliminating the boil-off. The results show the cryocooler was successful at removing 6.8 W of heat at approximately 75 K and 150 W of input power, with a heat rejection temperature of 311 K. The data generated on the ZBO components is essential for the upgrade of the ZBO Cryogenic Analysis Tool to more accurately apply the concept to future missions.

National and International Security Applications of Cryogenic Detectors—Mostly Nuclear Safeguards

NASA Astrophysics Data System (ADS)

Rabin, Michael W.

2009-12-01

As with science, so with security—in both arenas, the extraordinary sensitivity of cryogenic sensors enables high-confidence detection and high-precision measurement even of the faintest signals. Science applications are more mature, but several national and international security applications have been identified where cryogenic detectors have high potential payoff. International safeguards and nuclear forensics are areas needing new technology and methods to boost speed, sensitivity, precision and accuracy. Successfully applied, improved nuclear materials analysis will help constrain nuclear materials diversion pathways and contribute to treaty verification. Cryogenic microcalorimeter detectors for X-ray, gamma-ray, neutron, and alpha-particle spectrometry are under development with these aims in mind. In each case the unsurpassed energy resolution of microcalorimeters reveals previously invisible spectral features of nuclear materials. Preliminary results of quantitative analysis indicate substantial improvements are still possible, but significant work will be required to fully understand the ultimate performance limits.

Single ferromagnetic fluctuations in UCoGe revealed by 73Ge- and 59Co-NMR studies

NASA Astrophysics Data System (ADS)

Manago, Masahiro; Ishida, Kenji; Aoki, Dai

2018-02-01

73Ge and 59Co nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements have been performed on a 73Ge-enriched single-crystalline sample of the ferromagnetic superconductor UCoGe in the paramagnetic state. The 73Ge NQR parameters deduced from NQR and NMR are close to those of another isostructural ferromagnetic superconductor URhGe. The Knight shifts of the Ge and Co sites are well scaled to each other when the magnetic field is parallel to the b or c axis. The hyperfine coupling constants of Ge are estimated to be close to those of Co. The large difference of spin susceptibilities between the a and b axes could lead to the different response of the superconductivity and ferromagnetism with the field parallel to these directions. The temperature dependence of the nuclear spin-lattice relaxation rates 1 /T1 at the two sites is similar to each other above 5 K. These results indicate that the itinerant U-5 f electrons are responsible for the ferromagnetism in this compound, consistent with previous studies. The similarities and differences in the three ferromagnetic superconductors are discussed.

Structural damping studies at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Young, Clarence P., Jr.; Buehrle, Ralph D.

1994-01-01

Results of an engineering study to measure changes in structural damping properties of two cryogenic wind tunnel model systems and two metallic test specimens at cryogenic temperatures are presented. Data are presented which indicate overall, a trend toward reduced structural damping at cryogenic temperatures (-250 degrees F) when compared with room temperature damping properties. The study was focused on structures and materials used for model systems tested in the National Transonic Facility (NTF). The study suggests that the significant reductions in damping at extremely cold temperatures are most likely associated with changes in mechanical joint compliance damping rather than changes in material (solid) damping.

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.

Facesheet Delamination of Composite Sandwich Materials at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Gates, Thomas S.; Odegard, Gregory M.; Herring, Helen M.

2003-01-01

The next generation of space transportation vehicles will require advances in lightweight structural materials and related design concepts to meet the increased demands on performance. One potential source for significant structural weight reduction is the replacement of traditional metallic cryogenic fuel tanks with new designs for polymeric matrix composite tanks. These new tank designs may take the form of thin-walled sandwich constructed with lightweight core and composite facesheets. Life-time durability requirements imply the materials must safely carry pressure loads, external structural loads, resist leakage and operate over an extremely wide temperature range. Aside from catastrophic events like tank wall penetration, one of the most likely scenarios for failure of a tank wall of sandwich construction is the permeation of cryogenic fluid into the sandwich core and the subsequent delamination of the sandwich facesheet due to the build-up of excessive internal pressure. The research presented in this paper was undertaken to help understand this specific problem of core to facesheet delamination in cryogenic environments and relate this data to basic mechanical properties. The experimental results presented herein provide data on the strain energy release rate (toughness) of the interface between the facesheet and the core of a composite sandwich subjected to simulated internal pressure. A unique test apparatus and associated test methods are described and the results are presented to highlight the effects of cryogenic temperature on the measured material properties.

Low temperature growth of heavy boron-doped hydrogenated Ge epilayers and its application in Ge/Si photodetectors

NASA Astrophysics Data System (ADS)

Kuo, Wei-Cheng; Lee, Ming Jay; Wu, Mount-Learn; Lee, Chien-Chieh; Tsao, I.-Yu; Chang, Jenq-Yang

2017-04-01

In this study, heavily boron-doped hydrogenated Ge epilayers are grown on Si substrates at a low growth temperature (220 °C). The quality of the boron-doped epilayers is dependent on the hydrogen flow rate. The optical emission spectroscopic, X-ray diffraction and Hall measurement results demonstrate that better quality boron-doped Ge epilayers can be obtained at low hydrogen flow rates (0 sccm). This reduction in quality is due to an excess of hydrogen in the source gas, which breaks one of the Ge-Ge bonds on the Ge surface, leading to the formation of unnecessary dangling bonds. The structure of the boron doped Ge epilayers is analyzed by transmission electron microscopy and atomic force microscopy. In addition, the performance, based on the I-V characteristics, of Ge/Si photodetectors fabricated with boron doped Ge epilayers produced under different hydrogen flow rates was examined. The photodetectors with boron doped Ge epilayers produced with a low hydrogen flow rate (0 sccm) exhibited a higher responsivity of 0.144 A/W and a lower dark current of 5.33 × 10-7 A at a reverse bias of 1 V.

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.

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.

Vertical Ge photodetector base on InP taper waveguide

NASA Astrophysics Data System (ADS)

Amiri, Iraj Sadegh; Ariannejad, M. M.; Azzuhri, S. R. B.; Anwar, T.; Kouhdaragh, V.; Yupapin, P.

2018-06-01

In this work, simulation is conducted to investigate Ge photodetectors monolithically integrated on Si chip. The performance of vertical Germanium photodetector with FDTD Solutions (optical simulation) and electrical simulation has been studied. Selective heteroepitaxy of Ge is functioned in the monolithic integration of Ge photodetectors. The potential of CMOS-compatible monolithic integration of Ge as photodetector is investigated and the performance optimization is presented. Additionally, the investigation is extended to electrical part, particularly in the conversion efficiency as well as operation under low supplied voltage condition.

The Cryogenic Properties of Several Aluminum-Beryllium Alloys and a Beryllium Oxide Material

NASA Technical Reports Server (NTRS)

Gamwell, Wayne R.; McGill, Preston B.

2003-01-01

Performance related mechanical properties for two aluminum-beryllium (Al-Be) alloys and one beryllium-oxide (BeO) material were developed at cryogenic temperatures. Basic mechanical properties (Le., ultimate tensile strength, yield strength, percent elongation, and elastic modulus were obtained for the aluminum-beryllium alloy, AlBeMetl62 at cryogenic [-195.5"C (-320 F) and -252.8"C (-423"F)I temperatures. Basic mechanical properties for the Be0 material were obtained at cyrogenic [- 252.8"C (-423"F)] temperatures. Fracture properties were obtained for the investment cast alloy Beralcast 363 at cryogenic [-252.8"C (-423"F)] temperatures. The AlBeMetl62 material was extruded, the Be0 material was hot isostatic pressing (HIP) consolidated, and the Beralcast 363 material was investment cast.

Resonant cryogenic chopper. [for infrared and submillimeter radiometers

NASA Technical Reports Server (NTRS)

Page, Lyman A.; Cheng, Edward S.; Meyer, Stephan S.

1992-01-01

An account is given of the design features, construction, and performance of a both mechanically and thermally robust, resonant cryogenic chopper operating at 4.2 K. The chopper can occult a 2.54-cm aperture at 4.5 Hz, with approximately 1-mW dissipation. The controllability of the stator and rotor magnetic fields facilitates performance optimization and the determination of any possible interference effects. Attention is given to long-term amplitude stability determinations.

Commissioning of cryogenic system for China Spallation Neutron Source

NASA Astrophysics Data System (ADS)

Ye, Bin; He, Chongchao; Li, Na; Ding, Meiying; Wang, Yaqiong; Yu, Zhang; He, Kun

2017-12-01

China Spallation Neutron Source(CSNS) cryogenic system provides supercritical cryogenic hydrogen to neutron moderators, including a helium refrigerator, hydrogen loop and hydrogen safety equipment. The helium refrigerator is provided by Linde with cooling capacity of 2200 W at 20 K. Hydrogen loop system mainly includes cryogenic hydrogen pipes, hydrogen circulator cold-box and accumulator cold-box. Cryogenic hydrogen pump, ortho-para convertor, helium-hydrogen heat-exchanger, hydrogen heater and accumulator are integrated in hydrogen circulation cold-box, and accumulator cold-box. Hydrogen safety equipment includes safety valves, rupture disk, hydrogen sensor, flame detector and other equipment to ensure that cryogenic system in dangerous situations will go down, vents, or takes other measures. The cryogenic system commissioning work includes four steps. First, in order to test the refrigerating capacity of refrigerator, when acceptance testing, refrigerator internal heater was used as thermal load. Second, using simulation load as heat load of moderator, hydrogen loop use helium instead of hydrogen, and cooled down to 20 K, then re-warming and test the leak detection of hydrogen loop system. Third, base on the step 2, using hydrogen as working medium, and optimized the control logic. Forth, cryogenic system with the moderators joint commissioning. Now, cryogenic system is connected with the moderators, and the forth step will be carried out in the near future.

Cryogenic Fluid Management Experiment (CFME) trunnion verification testing

NASA Technical Reports Server (NTRS)

Bailey, W. J.; Fester, D. A.

1983-01-01

The Cryogenic Fluid Management Experiment (CFME) was designed to characterize subcritical liquid hydrogen storage and expulsion in the low-g space environment. The CFME has now become the storage and supply tank for the Cryogenic Fluid Management Facility, which includes transfer line and receiver tanks, as well. The liquid hydrogen storage and supply vessel is supported within a vacuum jacket to two fiberglass/epoxy composite trunnions which were analyzed and designed. Analysis using the limited available data indicated the trunnion was the most fatigue critical component in the storage vessel. Before committing the complete storage tank assembly to environmental testing, an experimental assessment was performed to verify the capability of the trunnion design to withstand expected vibration and loading conditions. Three tasks were conducted to evaluate trunnion integrity. The first determined the fatigue properties of the trunnion composite laminate materials. Tests at both ambient and liquid hydrogen temperatures showed composite material fatigue properties far in excess of those expected. Next, an assessment of the adequacy of the trunnion designs was performed (based on the tested material properties).

Sn-based Ge/Ge{sub 0.975}Sn{sub 0.025}/Ge p-i-n photodetector operated with back-side illumination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C.; Li, H.; Huang, S. H.

2016-04-11

We report an investigation of a GeSn-based p-i-n photodetector grown on a Ge wafer that collects light signal from the back of the wafer. Temperature dependent absorption measurements performed over a wide temperature range (300 K down to 25 K) show that (a) absorption starts at the indirect bandgap of the active GeSn layer and continues up to the direct bandgap of the Ge wafer, and (b) the peak responsivity increases rapidly at first with decreasing temperature, then increases more slowly, followed by a decrease at the lower temperatures. The maximum responsivity happens at 125 K, which can easily be achieved with themore » use of liquid nitrogen. The temperature dependence of the photocurrent is analyzed by taking into consideration of the temperature dependence of the electron and hole mobility in the active layer, and the analysis result is in reasonable agreement with the data in the temperature regime where the rapid increase occurs. This investigation demonstrates the feasibility of a GeSn-based photodiode that can be operated with back-side illumination for applications in image sensing systems.« less

Kinetic study of GeO disproportionation into a GeO{sub 2}/Ge system using x-ray photoelectron spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Shengkai; Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656; CREST, Japan Science and Technology Agency

2012-08-06

GeO disproportionation into GeO{sub 2} and Ge is studied through x-ray photoelectron spectroscopy. Direct evidence for the reaction 2GeO {yields} GeO{sub 2} + Ge after annealing in ultra-high vacuum is presented. Activation energy for GeO disproportionation is found to be about 0.7 {+-} 0.2 eV through kinetic and thermodynamic calculations. A kinetic model of GeO disproportionation is established by considering oxygen transfer in the GeO network. The relationship between GeO disproportionation and GeO desorption induced by GeO{sub 2}/Ge interfacial reaction is discussed, and the apparent contradiction between GeO desorption via interfacial redox reaction and GeO disproportionation into Ge and GeO{submore » 2} is explained by considering the oxygen vacancy.« less

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.

Three-dimensional hierarchical GeSe2 nanostructures for high performance flexible all-solid-state supercapacitors.

PubMed

Wang, Xianfu; Liu, Bin; Wang, Qiufan; Song, Weifeng; Hou, Xiaojuan; Chen, Di; Cheng, Yi-bing; Shen, Guozhen

2013-03-13

Highly flexible stacked and in-plane all-solid-state supercapacitors are fabricated on 3D hierarchical GeSe2 nanostructures with high performance, and, when configured as a self-powered photodetector nanosystem, can be used to power CdSe nanowire photodetectors. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of Cryogenic Cycle with Process Modeling Tool: Aspen HYSYS

NASA Astrophysics Data System (ADS)

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

2015-10-01

Cryogenic engineering deals with the development and improvement of low temperature techniques, processes and equipment. A process simulator such as Aspen HYSYS, for the design, analysis, and optimization of process plants, has features that accommodate the special requirements and therefore can be used to simulate most cryogenic liquefaction and refrigeration processes. Liquefaction is the process of cooling or refrigerating a gas to a temperature below its critical temperature so that liquid can be formed at some suitable pressure which is below the critical pressure. Cryogenic processes require special attention in terms of the integration of various components like heat exchangers, Joule-Thompson Valve, Turbo expander and Compressor. Here, Aspen HYSYS, a process modeling tool, is used to understand the behavior of the complete plant. This paper presents the analysis of an air liquefaction plant based on the Linde cryogenic cycle, performed using the Aspen HYSYS process modeling tool. It covers the technique used to find the optimum values for getting the maximum liquefaction of the plant considering different constraints of other parameters. The analysis result so obtained gives clear idea in deciding various parameter values before implementation of the actual plant in the field. It also gives an idea about the productivity and profitability of the given configuration plant which leads to the design of an efficient productive plant.

Cryogenic Optical Position Encoders for Mechanisms in the JWST Optical Telescope Element Simulator (OSIM)

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.; Anderjaska, Thomas; Badger, James (Inventor); Capon, Tom; Davis, CLinton; Dicks, Brent (Inventor); Eichhorn, William; Garza, Mario; Guishard, Corina; Haghani, Shadan;

Combination of Ultrasonic Vibration and Cryogenic Cooling for Cutting Performance Improvement of Inconel 718 Turning

NASA Astrophysics Data System (ADS)

Lin, S. Y.; Chung, C. T.; Cheng, Y. Y.

2011-01-01

The main objective of this study is to develop a thermo-elastic-plastic coupling model, based on a combination skill of ultrasonically assisted cutting and cryogenic cooling, under large deformation for Inconel 718 alloy machining process. The improvement extent on cutting performance and tool life promotion may be examined from this investigation. The critical value of the strain energy density of the workpiece will be utilized as the chip separation and the discontinuous chip segmentation criteria. The forced convection cooling and a hydrodynamic lubrication model will be considered and formulated in the model. Finite element method will be applied to create a complete numerical solution for this ultrasonic vibration cutting model. During the analysis, the cutting tool is incrementally advanced forward with superimposed ultrasonic vibration in a back and forth step-by-step manner, from an incipient stage of tool-workpiece engagement to a steady state of chip formation, a whole simulation of orthogonal cutting process under plane strain deformation is thus undertaken. High shear strength induces a fluctuation phenomenon of shear angle, high shear strain rate, variation of chip types and chip morphology, tool-chip contact length variation, the temperature distributions within the workpiece, chip and tool, periodic fluctuation in cutting forces can be determined from the developed model. A complete comparison of machining characteristics between some different combinations of ultrasonically assisted cutting and cryogenic cooling with conventional cutting operation can be acquired. Finally, the high-speed turning experiment for Inconel 718 alloy will be taken in the laboratory to validate the accuracy of the model, and the progressive flank wear, crater wear, notching and chipping of the tool edge can also be measured in the experiments.

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.

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.

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.

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.

Comparison of cryogenic low-pass filters.

PubMed

Thalmann, M; Pernau, H-F; Strunk, C; Scheer, E; Pietsch, T

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

Comparison of cryogenic low-pass filters

NASA Astrophysics Data System (ADS)

Thalmann, M.; Pernau, H.-F.; Strunk, C.; Scheer, E.; Pietsch, T.

2017-11-01

Low-temperature electronic transport measurements with high energy resolution require both effective low-pass filtering of high-frequency input noise and an optimized thermalization of the electronic system of the experiment. In recent years, elaborate filter designs have been developed for cryogenic low-level measurements, driven by the growing interest in fundamental quantum-physical phenomena at energy scales corresponding to temperatures in the few millikelvin regime. However, a single filter concept is often insufficient to thermalize the electronic system to the cryogenic bath and eliminate spurious high frequency noise. Moreover, the available concepts often provide inadequate filtering to operate at temperatures below 10 mK, which are routinely available now in dilution cryogenic systems. Herein we provide a comprehensive analysis of commonly used filter types, introduce a novel compact filter type based on ferrite compounds optimized for the frequency range above 20 GHz, and develop an improved filtering scheme providing adaptable broad-band low-pass characteristic for cryogenic low-level and quantum measurement applications at temperatures down to few millikelvin.

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.

Preparation of fine-particles at cryogenic temperatures

NASA Technical Reports Server (NTRS)

Globus, H.

1970-01-01

Flash freezing process yields gelling agent for use at cryogenic temperatures. Vaporized material, diluted with an inert gas, is injected below the surface of an agitated cryogenic liquid. This method disperses particles of chlorine trifluoride in liquid oxygen difluoride.

Advances in cryogenic engineering. Vols. 35A & 35B - Proceedings of the 1989 Cryogenic Engineering Conference, University of California, Los Angeles, July 24-28, 1989

NASA Astrophysics Data System (ADS)

Fast, R. W.

The book presents a review of literature on superfluid helium, together with papers under the topics on heat and mass transfer in He II; applications of He II for cooling superconducting devices in space; heat transfer to liquid helium and liquid nitrogen; multilayer insulation; applications of superconductivity, including topics on magnets and other devices, magnet stability and coil protection, and cryogenic techniques; and refrigeration for electronics. Other topics discussed include refrigeration of superconducting systems; the expanders, cold compressors, and pumps for liquid helium; dilution refrigerators; magnetic refrigerators; pulse tube refrigerators; cryocoolers for space applications; properties of cryogenic fluids; cryogenic instrumentation; hyperconducting devices (cryogenic magnets); cryogenic applications in space science and technology and in transportation; and miscellaneous cryogenic techniques and applications.

High-gain cryogenic amplifier assembly employing a commercial CMOS operational amplifier.

PubMed

Proctor, J E; Smith, A W; Jung, T M; Woods, S I

2015-07-01

We have developed a cryogenic amplifier for the measurement of small current signals (10 fA-100 nA) from cryogenic optical detectors. Typically operated with gain near 10(7) V/A, the amplifier performs well from DC to greater than 30 kHz and exhibits noise level near the Johnson limit. Care has been taken in the design and materials to control heat flow and temperatures throughout the entire detector-amplifier assembly. A simple one-board version of the amplifier assembly dissipates 8 mW to our detector cryostat cold stage, and a two-board version can dissipate as little as 17 μW to the detector cold stage. With current noise baseline of about 10 fA/(Hz)(1/2), the cryogenic amplifier is generally useful for cooled infrared detectors, and using blocked impurity band detectors operated at 10 K, the amplifier enables noise power levels of 2.5 fW/(Hz)(1/2) for detection of optical wavelengths near 10 μm.

Preliminary design trade-offs for a multi-mission stored cryogen cooler

NASA Technical Reports Server (NTRS)

Sherman, A.

1978-01-01

Preliminary design studies were performed for a multi-mission solid cryogen cooler having a wide range of application for both the shuttle sortie and free flyer missions. This multi-mission cooler (MMC) is designed to be utilized with various solid cryogens to meet a wide range of instrument cooling from 10 K (with solid hydrogen) to 90 K. The baseline cooler utilizes two stages of solid cryogen and incorporates an optional, higher temperature third stage which is cooled by either a passive radiator or a thermoelectric cooler. The MMC has an interface which can accommodate a wide variety of instrument configurations. A shrink fit adapter is incorporated which allows a drop-in instrument integration. The baseline design provides cooling of approximately 1 watt over a 60 to 100 K temperature range and about 0.5 watts from 15 to 60 K for a one year lifetime. For low cooling loads and with use of the optional radiator shield, cooling lifetimes as great as 8 years are predicted.

Multispectral optical telescope alignment testing for a cryogenic space environment

NASA Astrophysics Data System (ADS)

Newswander, Trent; Hooser, Preston; Champagne, James

2016-09-01

Multispectral space telescopes with visible to long wave infrared spectral bands provide difficult alignment challenges. The visible channels require precision in alignment and stability to provide good image quality in short wavelengths. This is most often accomplished by choosing materials with near zero thermal expansion glass or ceramic mirrors metered with carbon fiber reinforced polymer (CFRP) that are designed to have a matching thermal expansion. The IR channels are less sensitive to alignment but they often require cryogenic cooling for improved sensitivity with the reduced radiometric background. Finding efficient solutions to this difficult problem of maintaining good visible image quality at cryogenic temperatures has been explored with the building and testing of a telescope simulator. The telescope simulator is an onaxis ZERODUR® mirror, CFRP metered set of optics. Testing has been completed to accurately measure telescope optical element alignment and mirror figure changes in a cryogenic space simulated environment. Measured alignment error and mirror figure error test results are reported with a discussion of their impact on system optical performance.

The Effects of Annealing Temperatures on Composition and Strain in SixGe1−x Obtained by Melting Growth of Electrodeposited Ge on Si (100)

PubMed Central

Abidin, Mastura Shafinaz Zainal; Morshed, Tahsin; Chikita, Hironori; Kinoshita, Yuki; Muta, Shunpei; Anisuzzaman, Mohammad; Park, Jong-Hyeok; Matsumura, Ryo; Mahmood, Mohamad Rusop; Sadoh, Taizoh; Hashim, Abdul Manaf

2014-01-01

The effects of annealing temperatures on composition and strain in SixGe1−x, obtained by rapid melting growth of electrodeposited Ge on Si (100) substrate were investigated. Here, a rapid melting process was performed at temperatures of 1000, 1050 and 1100°C for 1 s. All annealed samples show single crystalline structure in (100) orientation. A significant appearance of Si-Ge vibration mode peak at ~00 cm−1 confirms the existence of Si-Ge intermixing due to out-diffusion of Si into Ge region. On a rapid melting process, Ge melts and reaches the thermal equilibrium in short time. Si at Ge/Si interface begins to dissolve once in contact with the molten Ge to produce Si-Ge intermixing. The Si fraction in Si-Ge intermixing was calculated by taking into account the intensity ratio of Ge-Ge and Si-Ge vibration mode peaks and was found to increase with the annealing temperatures. It is found that the strain turns from tensile to compressive as the annealing temperature increases. The Si fraction dependent thermal expansion coefficient of SixGe1−x is a possible cause to generate such strain behavior. The understanding of compositional and strain characteristics is important in Ge/Si heterostructure as these properties seem to give significant effects in device performance. PMID:28788521

The Effects of Annealing Temperatures on Composition and Strain in Si x Ge1-x Obtained by Melting Growth of Electrodeposited Ge on Si (100).

PubMed

Abidin, Mastura Shafinaz Zainal; Morshed, Tahsin; Chikita, Hironori; Kinoshita, Yuki; Muta, Shunpei; Anisuzzaman, Mohammad; Park, Jong-Hyeok; Matsumura, Ryo; Mahmood, Mohamad Rusop; Sadoh, Taizoh; Hashim, Abdul Manaf

2014-02-24

The effects of annealing temperatures on composition and strain in Si x Ge 1- x , obtained by rapid melting growth of electrodeposited Ge on Si (100) substrate were investigated. Here, a rapid melting process was performed at temperatures of 1000, 1050 and 1100 °C for 1 s. All annealed samples show single crystalline structure in (100) orientation. A significant appearance of Si-Ge vibration mode peak at ~400 cm -1 confirms the existence of Si-Ge intermixing due to out-diffusion of Si into Ge region. On a rapid melting process, Ge melts and reaches the thermal equilibrium in short time. Si at Ge/Si interface begins to dissolve once in contact with the molten Ge to produce Si-Ge intermixing. The Si fraction in Si-Ge intermixing was calculated by taking into account the intensity ratio of Ge-Ge and Si-Ge vibration mode peaks and was found to increase with the annealing temperatures. It is found that the strain turns from tensile to compressive as the annealing temperature increases. The Si fraction dependent thermal expansion coefficient of Si x Ge 1- x is a possible cause to generate such strain behavior. The understanding of compositional and strain characteristics is important in Ge/Si heterostructure as these properties seem to give significant effects in device performance.

RMs1: qualification results of the rotary miniature Stirling cryocooler at Thales Cryogenics

NASA Astrophysics Data System (ADS)

Martin, Jean-Yves; Seguineau, Cédric; Van-Acker, Sébastien; Sacau, Mikel; Le Bordays, Julien; Etchanchu, Thierry; Vasse, Christophe; Abadie, Christian; Laplagne, Gilles; Benschop, Tonny

2017-05-01

The trend for miniaturized Integrated Dewar and Cooler Assemblies (IDCA) has been confirmed over the past few years with several mentions of a new generation of IR detector working at High Operating Temperature (HOT). This key technology enables the use of cryocooler with reduced needs of cryogenics power. As a consequence, miniaturized IDCA are the combination of a HOT IR detector coupled with a low-size, low-weight and low-power (SWaP) cryocooler. Thales Cryogenics has developed his own line of SWaP products. Qualification results on linear solution where shown last year. The current paper focuses on the latest results obtained on RMs1 prototypes, the new rotary SWaP cryocooler from Thales Cryogenics. Cryogenic performances and induced vibrations are presented. In a second part, progress is discussed on compactness and weight on one side, and on power consumption on the other side. It shows how the trade-off made between weight and power consumption could lead to an optimized solution at system level. At least, an update is made on the qualification status.

Experimental investigation of the heat transfer characteristics of a helium cryogenic thermosyphon

NASA Astrophysics Data System (ADS)

Long, Z. Q.; Zhang, P.

2013-10-01

The heat transfer performance of a cryogenic thermosyphon filled with helium as the working fluid is investigated experimentally with a G-M cryocooler as the heat sink in this study. The cryogenic thermosyphon acts as a thermal link between the cryocooler and the cooled target (the copper evaporator with a large mass). Helium is charged in different filling ratios, and the cooling down process and the heat transfer characteristics of the cryogenic thermosyphon are investigated. The cooling down process of the cooled target can be significantly accelerated by the presence of helium in the cryogenic thermosyphon and the cooling down period can be further shortened by the increase of filling ratio. The heat transfer mode changes from the liquid-vapor phase change to natural convection as the increase of the heating power applied on the evaporator. The heat transfer limit and thermal resistance are discussed for the liquid-vapor phase change heat transfer, and they can be estimated by empirical correlations. For the natural convection heat transfer, it can be enhanced by increasing the filling ratio, and the natural convection of supercritical helium is much stronger than that of gaseous helium.

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

Study of Cryogenic Complex Plasma

DTIC Science & Technology

2010-08-17

inner diameter of 9.6 cm and the height of 80 cm. The Dewar bottle is filled with liquid helium or liquid nitrogen and is inserted in a liquid ...gas in the glass tube is controlled by the cryogenic liquid , liquid helium or liquid nitrogen , contained in the inner Dewar bottle. The outer Dewar...bottle contains liquid nitrogen to maintain the inner cryogenic temperature. An rf helium plasma with a neutral gas pressure P = 0.1 ~ 100 Pa is

Paint Removal Using Cryogenic Processes

DTIC Science & Technology

1992-01-01

perature. Low-carbon 3 percent nickel steel has impact strength to -100 0 F, low-carbon 9 percent nickel steel and maraging (high nickel) steel to -3201F...by cryogenic meth- ods. Cryogenic methods aie not rccommended for use on ships because of the danger of steel embrittlement by low temperatures. It...not recommended for use on ships because of the danger of steel embrittlement by low temperalures. It was demonstrated that a jet of liquid nitrogen

Cu2ZnGeS4 thin films deposited by thermal evaporation: the impact of Ge concentration on physical properties

NASA Astrophysics Data System (ADS)

Courel, Maykel; Sanchez, T. G.; Mathews, N. R.; Mathew, X.

2018-03-01

In this work, the processing of Cu2ZnGeS4 (CZGS) thin films by a thermal evaporation technique starting from CuS, GeS and ZnS precursors, and post-deposition thermal processing, is discussed. Batches of films with GeS layers of varying thicknesses are deposited in order to study the role of Ge concentration on the structural, morphological, optical and electrical properties of CZGS films. The formation of the CZGS compound with a tetragonal phase and a kesterite structure is confirmed for all samples using XRD and Raman studies. An improvement in crystallite size for Ge-poor films is also observed in the XRD analysis, which is in good agreement with the grain size observed in the cross section SEM image. Furthermore, it is found that the band-gap of CZGS film can be tailored in the range of 2.0-2.23 eV by varying Ge concentration. A comprehensive electrical characterization is also performed which demonstrates that slightly Ge-poor samples are described by the lowest grain boundary defect densities and the highest photosensitivity and mobility values. A study of the work function of CZGS samples with different Ge concentrations is also presented. Finally, a theoretical evaluation is presented, considering, under ideal conditions, the possible impact of these films on device performance. Based on the characterization results, it is concluded that Ge-poor CZGS samples deposited by thermal evaporation present better physical properties for device applications.

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

NASA Technical Reports Server (NTRS)

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

2003-01-01

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

On-wafer, cryogenic characterization of ultra-low noise HEMT devices

NASA Technical Reports Server (NTRS)

Bautista, J. J.; Laskar, J.; Szydlik, P.

1995-01-01

Significant advances in the development of high electron-mobility field-effect transistors (HEMT's) have resulted in cryogenic, low-noise amplifiers (LNA's) whose noise temperatures are within an order of magnitude of the quantum noise limit (hf/k). Further advances in HEMT technology at cryogenic temperatures may eventually lead to the replacement of maser and superconducting insulator superconducting front ends in the 1- to 100-GHz frequency band. Key to identification of the best HEMT's and optimization of cryogenic LNA's are accurate and repeatable device measurements at cryogenic temperatures. This article describes the design and operation of a cryogenic coplanar waveguide probe system for the characterization and modeling of advanced semiconductor transistors at cryogenic temperatures. Results on advanced HEMT devices are presented to illustrate the utility of the measurement system.

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.

Comparative analysis on flexibility requirements of typical Cryogenic Transfer lines

NASA Astrophysics Data System (ADS)

Jadon, Mohit; Kumar, Uday; Choukekar, Ketan; Shah, Nitin; Sarkar, Biswanath

2017-04-01

The cryogenic systems and their applications; primarily in large Fusion devices, utilize multiple cryogen transfer lines of various sizes and complexities to transfer cryogenic fluids from plant to the various user/ applications. These transfer lines are composed of various critical sections i.e. tee section, elbows, flexible components etc. The mechanical sustainability (under failure circumstances) of these transfer lines are primary requirement for safe operation of the system and applications. The transfer lines need to be designed for multiple design constraints conditions like line layout, support locations and space restrictions. The transfer lines are subjected to single load and multiple load combinations, such as operational loads, seismic loads, leak in insulation vacuum loads etc. [1]. The analytical calculations and flexibility analysis using professional software are performed for the typical transfer lines without any flexible component, the results were analysed for functional and mechanical load conditions. The failure modes were identified along the critical sections. The same transfer line was then refurbished with the flexible components and analysed for failure modes. The flexible components provide additional flexibility to the transfer line system and make it safe. The results obtained from the analytical calculations were compared with those obtained from the flexibility analysis software calculations. The optimization of the flexible component’s size and selection was performed and components were selected to meet the design requirements as per code.

Reusable Cryogenic Tank VHM Using Fiber Optic Distributed Sensing Technology

NASA Technical Reports Server (NTRS)

Bodan-Sanders, Patricia; Bouvier, Carl

1998-01-01

The reusable oxygen and hydrogen tanks are key systems for both the X-33 (sub-scale, sub-orbital technology demonstrator) and the commercial Reusable Launch Vehicle (RLV). The backbone of the X-33 Reusable Cryogenic Tank Vehicle Health Management (VHM) system lies in the optical network of distributed strain temperature and hydrogen sensors. This network of fiber sensors will create a global strain and temperature map for monitoring the health of the tank structure, cryogenic insulation, and Thermal Protection System. Lockheed Martin (Sanders and LMMSS) and NASA Langley have developed this sensor technology for the X-33 and have addressed several technical issues such as fiber bonding and laser performance in this harsh environment.

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.

Thin SiGe virtual substrates for Ge heterostructures integration on silicon

NASA Astrophysics Data System (ADS)

Cecchi, S.; Gatti, E.; Chrastina, D.; Frigerio, J.; Müller Gubler, E.; Paul, D. J.; Guzzi, M.; Isella, G.

2014-03-01

The possibility to reduce the thickness of the SiGe virtual substrate, required for the integration of Ge heterostructures on Si, without heavily affecting the crystal quality is becoming fundamental in several applications. In this work, we present 1 μm thick Si1-xGex buffers (with x > 0.7) having different designs which could be suitable for applications requiring a thin virtual substrate. The rationale is to reduce the lattice mismatch at the interface with the Si substrate by introducing composition steps and/or partial grading. The relatively low growth temperature (475 °C) makes this approach appealing for complementary metal-oxide-semiconductor integration. For all the investigated designs, a reduction of the threading dislocation density compared to constant composition Si1-xGex layers was observed. The best buffer in terms of defects reduction was used as a virtual substrate for the deposition of a Ge/SiGe multiple quantum well structure. Room temperature optical absorption and photoluminescence analysis performed on nominally identical quantum wells grown on both a thick graded virtual substrate and the selected thin buffer demonstrates a comparable optical quality, confirming the effectiveness of the proposed approach.

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

NASA Technical Reports Server (NTRS)

Woike, Thomas J.

1993-01-01

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

Foam vessel for cryogenic fluid storage

DOEpatents

Spear, Jonathan D [San Francisco, CA

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.

Correction of Dynamic Characteristics of SAR Cryogenic GTE on Consumption of Gasified Fuel

NASA Astrophysics Data System (ADS)

Bukin, V. A.; Gimadiev, A. G.; Gangisetty, G.

2018-01-01

When the gas turbine engines (GTE) NK-88 were developed for liquid hydrogen and NK-89 for liquefied natural gas, performance of the systems with a turbo-pump unitary was improved and its proved without direct regulation of the flow of a cryogenic fuel, which was supplied by a centrifugal pump of the turbo-pump unit (TPU) Command from the “kerosene” system. Such type of the automatic control system (SAR) has the property of partial “neutralization” of the delay caused by gasification of the fuel. This does not require any measurements in the cryogenic medium, and the failure of the centrifugal cryogenic pump does not lead to engine failure. On the other hand, the system without direct regulation of the flow of cryogenic fuel has complex internal dynamic connections, their properties are determined by the characteristics of the incoming units and assemblies, and it is difficult to maintain accurate the maximum boundary level and minimum fuel consumption due to the influence of a booster pressure change. Direct regulation of the consumption of cryogenic fuel (prior to its gasification) is the preferred solution, since for using traditional liquid and gaseous fuels this is the main and proven method. The scheme of correction of dynamic characteristics of a single-loop SAR GTE for the consumption of a liquefied cryogenic fuel with a flow rate correction in its gasified state, which ensures the dynamic properties of the system is not worse than for NK-88 and NK-89 engines.

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.

Cryogenic mirror analysis

NASA Technical Reports Server (NTRS)

Nagy, S.

1988-01-01

Due to extraordinary distances scanned by modern telescopes, optical surfaces in such telescopes must be manufactured to unimaginable standards of perfection of a few thousandths of a centimeter. The detection of imperfections of less than 1/20 of a wavelength of light, for application in the building of the mirror for the Space Infrared Telescope Facility, was undertaken. Because the mirror must be kept very cold while in space, another factor comes into effect: cryogenics. The process to test a specific morror under cryogenic conditions is described; including the follow-up analysis accomplished through computer work. To better illustrate the process and analysis, a Pyrex Hex-Core mirror is followed through the process from the laser interferometry in the lab, to computer analysis via a computer program called FRINGE. This analysis via FRINGE is detailed.

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.

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.

Use of PROFIBUS for cryogenic instrumentation at XFEL

NASA Astrophysics Data System (ADS)

Boeckmann, T.; Bolte, J.; Bozhko, Y.; Clausen, M.; Escherich, K.; Korth, O.; Penning, J.; Rickens, H.; Schnautz, T.; Schoeneburg, B.; Zhirnov, A.

2017-12-01

The European X-ray Free Electron Laser (XFEL) is a research facility and since December 2016 under commissioning at DESY in Hamburg. The XFEL superconducting accelerator is 1.5 km long and contains 96 superconducting accelerator modules. The control system EPICS (Experimental Physics and Industrial Control System) is used to control and operate the XFEL cryogenic system consisting of the XFEL refrigerator, cryogenic distribution systems and the XFEL accelerator. The PROFIBUS fieldbus technology is the key technology of the cryogenic instrumentation and the link to the control system. More than 650 PROFIBUS nodes are implemented in the different parts of the XFEL cryogenic facilities. The presentation will give an overview of PROFIBUS installation in these facilities regarding engineering, possibilities of diagnostics, commissioning and the first operating experience.

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

NASA Technical Reports Server (NTRS)

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

2013-01-01

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

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.

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 882.4250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device...

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 882.4250 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4250 Cryogenic surgical device...

Performance enhancement of Ge-on-Insulator tunneling FETs with source junctions formed by low-energy BF2 ion implantation

NASA Astrophysics Data System (ADS)

Katoh, Takumi; Matsumura, Ryo; Takaguchi, Ryotaro; Takenaka, Mitsuru; Takagi, Shinichi

2018-04-01

To clarify the process of formation of source regions of high-performance Ge n-channel tunneling field-effect transistors (TFETs), p+-n junctions formed by low-energy ion implantation (I/I) of BF2 atoms are characterized. Here, the formation of p+-n junctions with steep B profiles and low junction leakage is a key issue. The steepness of 5.7 nm/dec in profiles of B implanted into Ge is obtained for BF2 I/I at 3 keV with a dose of 4 × 1014 cm-2. Ge-on-insulator (GOI) n-TFETs with the source tunnel junctions formed by low-energy B and BF2 I/I are fabricated on GOI substrates and the device operation is confirmed. Although the performance at room temperature is significantly degraded by the source junction leakage current, an I on/I off ratio of 105 and the minimum sub-threshold swing (S.S.) of 130 mV/dec are obtained at 10 K. It is found that GOI n-TFETs with steeper B profiles formed by BF2 I/I have led to higher on current and a lower sub-threshold slope, demonstrating the effectiveness of steep B profiles in enhancing the GOI TFET performance.

Across-Gimbal and Miniaturized Cryogenic Loop Heat Pipes

NASA Astrophysics Data System (ADS)

Bugby, D.; Marland, B.; Stouffer, C.; Kroliczek, E.

2003-01-01

This paper describes the development status of three advanced cryogenic loop heat pipes (CLHP) for solving important problems in cryogenic integration. The three devices described herein are: (1) an across-gimbal CLHP; (2) a short transport length miniaturized CLHP; and (3) a long transport length miniaturized CLHP. The across-gimbal CLHP, which is baselined for operation from 80-100 K with nitrogen, provides a low weight, low torque, high conductance solution for gimbaled cryogenic systems wishing to mount their cryocoolers off-gimbal. The short transport length miniaturized CLHP, which is baselined for operation near 35 K with neon, combines localized thermal transport, flexibility, and thermal switching into one device that can be directly mounted to a cryocooler cold head and a cryogenic component just a short distance (10-20 cm) away. The long transport length miniaturized CLHP, which is also baselined for operation near 35 K with neon, adds to the capabilities of the short transport length miniaturized CLHP by increasing the transport length to over 250 cm to meet cryogenic heat transport device requirements of future NASA and DoD spacecraft.

A new cryogenic diode thermometer

NASA Astrophysics Data System (ADS)

Courts, S. S.; Swinehart, P. R.; Yeager, C. J.

2002-05-01

While the introduction of yet another cryogenic diode thermometer is not earth shattering, a new diode thermometer, the DT-600 series, recently introduced by Lake Shore Cryotronics, possesses three features that make it unique among commercial diode thermometers. First, these diodes have been probed at the chip level, allowing for the availability of a bare chip thermometer matching a standard curve-an important feature in situations where real estate is at a premium (IR detectors), or where in-situ calibration is difficult. Second, the thermometry industry has assumed that interchangeability should be best at low temperatures. Thus, good interchangeability at room temperatures implies a very good interchangeability at cryogenic temperature, resulting in a premium priced sensor. The DT-600 series diode thermometer is available in an interchangeability band comparable to platinum RTDs with the added advantage of interchangeability to 2 K. Third, and most important, the DT-600 series diode does not exhibit an instability in the I-V characteristic in the 8 K to 20 K temperature range that is observed in other commercial diode thermometer devices [1]. This paper presents performance characteristics for the DT-600 series diode thermometer along with a comparison of I-V curves for this device and other commercial diode thermometers exhibiting an I-V instability.

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.

Large-Scale Cryogen Systems and Test Facilities

NASA Technical Reports Server (NTRS)

Johnson, R. G.; Sass, J. P.; Hatfield, W. H.

2007-01-01

NASA has completed initial construction and verification testing of the Integrated Systems Test Facility (ISTF) Cryogenic Testbed. The ISTF is located at Complex 20 at Cape Canaveral Air Force Station, Florida. The remote and secure location is ideally suited for the following functions: (1) development testing of advanced cryogenic component technologies, (2) development testing of concepts and processes for entire ground support systems designed for servicing large launch vehicles, and (3) commercial sector testing of cryogenic- and energy-related products and systems. The ISTF Cryogenic Testbed consists of modular fluid distribution piping and storage tanks for liquid oxygen/nitrogen (56,000 gal) and liquid hydrogen (66,000 gal). Storage tanks for liquid methane (41,000 gal) and Rocket Propellant 1 (37,000 gal) are also specified for the facility. A state-of-the-art blast proof test command and control center provides capability for remote operation, video surveillance, and data recording for all test areas.

Fiber-based confocal microscope for cryogenic spectroscopy.

PubMed

Högele, Alexander; Seidl, Stefan; Kroner, Martin; Karrai, Khaled; Schulhauser, Christian; Sqalli, Omar; Scrimgeour, Jan; Warburton, Richard J

2008-02-01

We describe the design and performance of a fiber-based confocal microscope for cryogenic operation. The microscope combines positioning at low temperatures along three space coordinates of millimeter translation and nanometer precision with high stability and optical performance at the diffraction limit. It was successfully tested under ambient conditions as well as at liquid nitrogen (77 K) and liquid helium (4 K) temperatures. The compact nonmagnetic design provides for long term position stability against helium refilling transfers, temperature sweeps, as well as magnetic field variation between -9 and 9 T. As a demonstration of the microscope performance, applications in the spectroscopy of single semiconductor quantum dots are presented.

Development of dual solid cryogens for high reliability refrigeration system

NASA Technical Reports Server (NTRS)

Caren, R. P.; Coston, R. M.

1967-01-01

High reliability solid cryogen refrigeration system consists of a container initially filled with a solid cryogen which is coupled thermally to an infrared detector by means of a link of high thermal conductivity extending from a heat exchanger within the cryogen container.

Ge/Si(001) heterostructures with dense arrays of Ge quantum dots: morphology, defects, photo-emf spectra and terahertz conductivity.

PubMed

Yuryev, Vladimir A; Arapkina, Larisa V; Storozhevykh, Mikhail S; Chapnin, Valery A; Chizh, Kirill V; Uvarov, Oleg V; Kalinushkin, Victor P; Zhukova, Elena S; Prokhorov, Anatoly S; Spektor, Igor E; Gorshunov, Boris P

2012-07-23

: Issues of Ge hut cluster array formation and growth at low temperatures on the Ge/Si(001) wetting layer are discussed on the basis of explorations performed by high resolution STM and in-situ RHEED. Dynamics of the RHEED patterns in the process of Ge hut array formation is investigated at low and high temperatures of Ge deposition. Different dynamics of RHEED patterns during the deposition of Ge atoms in different growth modes is observed, which reflects the difference in adatom mobility and their 'condensation' fluxes from Ge 2D gas on the surface for different modes, which in turn control the nucleation rates and densities of Ge clusters. Data of HRTEM studies of multilayer Ge/Si heterostructures are presented with the focus on low-temperature formation of perfect films.Heteroepitaxial Si p-i-n-diodes with multilayer stacks of Ge/Si(001) quantum dot dense arrays built in intrinsic domains have been investigated and found to exhibit the photo-emf in a wide spectral range from 0.8 to 5 μm. An effect of wide-band irradiation by infrared light on the photo-emf spectra has been observed. Photo-emf in different spectral ranges has been found to be differently affected by the wide-band irradiation. A significant increase in photo-emf is observed in the fundamental absorption range under the wide-band irradiation. The observed phenomena are explained in terms of positive and neutral charge states of the quantum dot layers and the Coulomb potential of the quantum dot ensemble. A new design of quantum dot infrared photodetectors is proposed.By using a coherent source spectrometer, first measurements of terahertz dynamical conductivity (absorptivity) spectra of Ge/Si(001) heterostructures were performed at frequencies ranged from 0.3 to 1.2 THz in the temperature interval from 300 to 5 K. The effective dynamical conductivity of the heterostructures with Ge quantum dots has been discovered to be significantly higher than that of the structure with the same amount of bulk

Performance of Ge-Sb-Bi-Te-B Recording Media for Phase-Change Optical Disks

NASA Astrophysics Data System (ADS)

Lee, Chain-Ming; Yen, Wen-Shin; Liu, Ren-Haur; Chin, Tsung-Shune

2001-09-01

We investigated the physical properties of GeSbBiTeB materials and examined the feasibility for phase change recording. The studied compositions were Ge4Sb0.5Bi0.5Te5 and Ge2Sb1.5Bi0.5Te5 with B doping. The coexistence of Bi and B atoms into both Ge4SbTe5 and Ge2Sb2Te5 lattice maintains single fcc structure without phase separation. The Bi substitution shows benefits in decreasing crystallization temperature and activation energy, however the reflectivity is slightly reduced. 3 With small amount addition of boron about 1 at.%, the reflectivity can be increased. 2 Conventional 4-layer structure of digital versatile disk-random access memory (DVD-RAM) 2.6 GB format was used to prepare the disks for dynamic characterization and overwrite cyclability evaluations. The disk with Ge4Sb0.5Bi0.5Te5(B) recording layer shows large noise fluctuation and low overwrite erase ratio, suggesting that the crystallization speed is still insufficient. While the disk with Ge2Sb1.5Bi0.5Te5(B) recording layer shows lower writing and erasing powers, stable noise level and high overwrite erase ratio, indicating the capability for DVD-RAM applications. The effect of B doping was verified to enhance the signal amplitude and modulation.

Membrane-augmented cryogenic methane/nitrogen separation

DOEpatents

Lokhandwala, Kaaeid

1997-01-01

A membrane separation process combined with a cryogenic separation process for treating a gas stream containing methane, nitrogen and at least one other component. The membrane separation process works by preferentially permeating methane and the other component and rejecting nitrogen. The process is particularly useful in removing components such as water, carbon dioxide or C.sub.3+ hydrocarbons that might otherwise freeze and plug the cryogenic equipment.

Cryogenics and its application with reference to spice grinding: a review.

PubMed

Balasubramanian, S; Gupta, Manoj Kumar; Singh, K K

2012-01-01

Cryogenics is the study of very low temperature and its application on different materials including biological products. Cryogenics has numerous applications in space science, electronics, automobiles, the manufacturing industry, sports and musical instruments, biological science and agriculture, etc. Cryogenic freezing finds pivotal application in food, that is, spices and condiments. Although there is a wide range of cryogens to produce the desired low temperature, generally liquid nitrogen (LN₂) is used in food grinding. The application of low temperature shows a promising pathway to produce higher quality end product with higher flavor and volatile oil retention. Cryogenic grinders generally consist of precoolers and grinder with the cryogen distribution system. In such grinding systems, cryogens subject the raw material up to or lower than glass transition temperature before it is ground, thus eliminating much of the material and quality hassles of traditional grinding. At present, the capital investment including cryogen and handling costs escalate the final cost of the product. Thus, for large-scale production, a proper design to optimize and make it feasible is the need of the hour and understanding the behavior of different food materials at these low temperature conditions. This article reviews the scenario and application of cryogenics in different sectors, especially to spice grinding.

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

NASA Technical Reports Server (NTRS)

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

1976-01-01

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

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.

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.

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

NASA Technical Reports Server (NTRS)

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

2002-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2017-03-01

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

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

PubMed

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

2017-12-01

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

Pressure-Induced Phase Transitions in GeTe-Rich Ge-Sb-Te Alloys across the Rhombohedral-to-Cubic Transitions.

PubMed

Krbal, Milos; Bartak, Jaroslav; Kolar, Jakub; Prytuliak, Anastasiia; Kolobov, Alexander V; Fons, Paul; Bezacier, Lucile; Hanfland, Michael; Tominaga, Junji

2017-07-17

We demonstrate that pressure-induced amorphization in Ge-Sb-Te alloys across the ferroelectric-paraelectric transition can be represented as a mixture of coherently distorted rhombohedral Ge 8 Sb 2 Te 11 and randomly distorted cubic Ge 4 Sb 2 Te 7 and high-temperature Ge 8 Sb 2 Te 11 phases. While coherent distortion in Ge 8 Sb 2 Te 11 does not prevent the crystalline state from collapsing into its amorphous counterpart in a similar manner to pure GeTe, the pressure-amorphized Ge 8 Sb 2 Te 11 phase begins to revert to the crystalline cubic phase at ∼9 GPa in contrast to Ge 4 Sb 2 Te 7 , which remains amorphous under ambient conditions when gradually decompressed from 40 GPa. Moreover, experimentally, it was observed that pressure-induced amorphization in Ge 8 Sb 2 Te 11 is a temperature-dependent process. Ge 8 Sb 2 Te 11 transforms into the amorphous phase at ∼27.5 and 25.2 GPa at room temperature and 408 K, respectively, and completely amorphizes at 32 GPa at 408 K, while some crystalline texture could be seen until 38 GPa (the last measurement point) at room temperature. To understand the origins of the temperature dependence of the pressure-induced amorphization process, density functional theory calculations were performed for compositions along the (GeTe) x - (Sb 2 Te 3 ) 1-x tie line under large hydrostatic pressures. The calculated results agreed well with the experimental data.

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.

Cryogenic Eyesafer Laser Optimization for Use Without Liquid Nitrogen

DTIC Science & Technology

2014-02-01

liquid cryogens. This calls for optimal performance around 125–150 K—high enough for reasonably efficient operation of a Stirling cooler. We...state laser system with an optimum operating temperature somewhat higher—ideally 125–150 K—can be identified, then a Stirling cooler can be used to...needed to optimize laser performance in the desired temperature range. This did not include actual use of Stirling coolers, but rather involved both

Cryogenic focussing, ohmically heated on-column trap

NASA Technical Reports Server (NTRS)

Springston, Stephen R.

1991-01-01

A procedure is described for depositing a conductive layer of gold on the exterior of a fused-silica capillary used in gas chromatography. By subjecting a section of the column near the inlet to a thermal cycle of cryogenic cooling and ohmic heating, volatile samples are concentrated and subsequently injected. The performance of this trap as a chromatographic injector is demonstrated. Several additional applications are suggested and the unique properties of this device are discussed.

Electronic Components and Systems for Cryogenic Space Applications

NASA Technical Reports Server (NTRS)

Patterson, R. L.; Hammoud, A.; Dickman, J. E.; Gerber, S.; Elbuluk, M. E.; Overton, E.

2001-01-01

Electronic components and systems capable of operation at cryogenic temperatures are anticipated in many future NASA space missions such as deep space probes and planetary surface exploration. For example, an unheated interplanetary probe launched to explore the rings of Saturn would reach an average temperature near Saturn of about - 183 C. In addition to surviving the deep space harsh environment, electronics capable of low temperature operation would contribute to improving circuit performance, increasing system efficiency, and reducing payload development and launch costs. Terrestrial applications where components and systems must operate in low temperature environments include cryogenic instrumentation, superconducting magnetic energy storage, magnetic levitation transportation system, and arctic exploration. An on-going research and development program at the NASA Glenn Research Center focuses on the development of reliable electronic devices and efficient power systems capable of surviving in low temperature environments. An overview of the program will be presented in this paper. A description of the low temperature test facilities along with selected data obtained from in-house component testing will also be discussed. Ongoing research activities that are being performed in collaboration with various organizations will also be presented.

Shuttle cryogenic supply system optimization study. Volume 6: Appendixes

NASA Technical Reports Server (NTRS)

1973-01-01

The optimization of the cryogenic supply system for space shuttles is discussed. The subjects considered are: (1) auxiliary power unit parametric data, (2) propellant acquisition, (3) thermal protection and thermodynamic properties, (4) instrumentation and controls, and (5) initial component redundancy evaluations. Diagrams of the systems are provided. Graphs of the performance capabilities are included.

Carbon fiber composites for cryogenic filament-wound vessels

NASA Technical Reports Server (NTRS)

Larsen, J. V.; Simon, R. A.

1972-01-01

Advanced unidirectional and bidirectional carbon fiber/epoxy resin composites were evaluated for physical and mechanical properties over a cryogenic to room temperature range for potential application to cryogenic vessels. The results showed that Courtaulds HTS carbon fiber was the superior fiber in terms of cryogenic strength properties in epoxy composites. Of the resin systems tested in ring composites, CTBN/ERLB 4617 exhibited the highest composite strengths at cryogenic temperatures, but very low interlaminar shear strengths at room temperature. Tests of unidirectional and bidirectional composite bars showed that the Epon 828/Empol 1040 resin was better at all test temperatures. Neither fatigue cycling nor thermal shock had a significant effect on composite strengths or moduli. Thermal expansion measurements gave negative values in the fiber direction and positive values in the transverse direction of the composites.

Investigation of mechanical properties of cryogenically treated music wire

NASA Astrophysics Data System (ADS)

Heptonstall, A.; Waller, M.; Robertson, N. A.

2015-08-01

It has been reported that treating music wire (high carbon steel wire) by cooling to cryogenic temperatures can enhance its mechanical properties with particular reference to those properties important for musical performance. We use such wire for suspending many of the optics in Advanced LIGO, the upgrade to LIGO—the Laser Interferometric Gravitational-Wave Observatory. Two properties that particularly interest us are mechanical loss and breaking strength. A decrease in mechanical loss would directly reduce the thermal noise associated with the suspension, thus enhancing the noise performance of mirror suspensions within the detector. An increase in strength could allow thinner wire to be safely used, which would enhance the dilution factor of the suspension, again leading to lower suspension thermal noise. In this article, we describe the results of an investigation into some of the mechanical properties of music wire, comparing untreated wire with the same wire which has been cryogenically treated. For the samples we studied, we conclude that there is no significant difference in the properties of interest for application in gravitational wave detectors.

Test Results of Selected Commercial DC/DC Converters under Cryogenic Temperatures - A Digest

NASA Technical Reports Server (NTRS)

Patterson, Richard; Hammoud, Ahmad

2010-01-01

DC/DC converters are widely used in space power systems in the areas of power management and distribution, signal conditioning, and motor control. Design of DC/DC converters to survive cryogenic temperatures will improve the power system performance, simplify design, and reduce development and launch costs. In this work, the performance of nine COTS modular, low-tomedium power DC/DC converters was investigated under cryogenic temperatures. The converters were evaluated in terms of their output regulation, efficiency, and input and output currents. At a given temperature, these properties were obtained at various input voltages and at different load levels. A summary on the performance of the tested converters was given. More comprehensive testing and in-depth analysis of performance under long-term exposure to extreme temperatures are deemed necessary to establish the suitability of these and other devices for use in the harsh environment of space exploration missions.

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.

A hybrid electronically scanned pressure module for cryogenic environments

NASA Technical Reports Server (NTRS)

Chapman, J. J.; Hopson, P., Jr.; Kruse, N.

1995-01-01

Pressure is one of the most important parameters measured when testing models in wind tunnels. For models tested in the cryogenic environment of the National Transonic Facility at NASA Langley Research Center, the technique of utilizing commercially available multichannel pressure modules inside the models is difficult due to the small internal volume of the models and the requirement of keeping the pressure transducer modules within an acceptable temperature range well above the -173 degrees C tunnel temperature. A prototype multichannel pressure transducer module has been designed and fabricated with stable, repeatable sensors and materials optimized for reliable performance in the cryogenic environment. The module has 16 single crystal silicon piezoresistive pressure sensors electrostatically bonded to a metalized Pyrex substrate for sensing the wind tunnel model pressures. An integral temperature sensor mounted on each silicon micromachined pressure sensor senses real-time temperature fluctuations to within 0.1 degrees C to correct for thermally induced non-random sensor drift. The data presented here are from a prototype sensor module tested in the 0.3 M cryogenic tunnel and thermal equilibrium conditions in an environmental chamber which approximates the thermal environment (-173 degrees C to +60 degrees C) of the National Transonic Facility.

Thermal modeling of a cryogenic turbopump for space shuttle applications.

NASA Technical Reports Server (NTRS)

Knowles, P. J.

1971-01-01

Thermal modeling of a cryogenic pump and a hot-gas turbine in a turbopump assembly proposed for the Space Shuttle is described in this paper. A model, developed by identifying the heat-transfer regimes and incorporating their dependencies into a turbopump system model, included heat transfer for two-phase cryogen, hot-gas (200 R) impingement on turbine blades, gas impingement on rotating disks and parallel plate fluid flow. The ?thermal analyzer' program employed to develop this model was the TRW Systems Improved Numerical Differencing Analyzer (SINDA). This program uses finite differencing with lumped parameter representation for each node. Also discussed are model development, simulations of turbopump startup/shutdown operations, and the effects of varying turbopump parameters on the thermal performance.

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.

Powder metallurgy of Ge, Si, and Ge-Si

NASA Astrophysics Data System (ADS)

Schilz, Jürgen; Langenbach, Marion

1993-03-01

id="ab1"Planetary ball-milling and pressing behaviour of Ge, Si and Ge-Si powder mixtures are investigated. Scanning and transmission electron microscopy observations revealed the different microstructure of the two elements after milling: Ge remains in a microcrystalline state, whereas Si can be comminuted into grains consisting of nanocrystalline regions. Planetary milling of the two elements together, using agate balls and vial, did not reveal any compound formation. By hot-isostatic pressing, pure Ge and Ge-Si mixtures were densified to a higher value than pure Si. This denotes a plastic flow of the Ge component at a process temperature of 800°C. The microhardness of hot-pressed Ge reaches the bulk value; hot-pressed Si is very soft. Energy dispersive X-ray analysis and X-ray diffraction did not detect any impurity contamination from vial and milling media wear. Moreover, by electrical transport measurements it turned out that the net carrier concentration density resulting from electrical active impurities introduced by the milling and pressing process is below 2 x 1016 cm 3 at room temperature.

Thermal Structures Technology Development for Reusable Launch Vehicle Cryogenic Propellant Tanks

NASA Technical Reports Server (NTRS)

Johnson, Theodore F.; Natividad, Roderick; Rivers, H. Kevin; Smith, Russell

1998-01-01

Analytical and experimental studies conducted at the NASA Langley Research Center for investigating integrated cryogenic propellant tank systems for a Reusable Launch Vehicle are described. The cryogenic tanks are investigated as an integrated tank system. An integrated tank system includes the tank wall, cryogenic insulation, Thermal Protection System (TPS) attachment sub-structure, and TPS. Analysis codes are used to size the thicknesses of cryogenic insulation and TPS insulation for thermal loads, and to predict tank buckling strengths at various ring frame spacings. The unique test facilities developed for the testing of cryogenic tank components are described. Testing at cryogenic and high-temperatures verifies the integrity of materials, design concepts, manufacturing processes, and thermal/structural analyses. Test specimens ranging from the element level to the subcomponent level are subjected to projected vehicle operational mechanical loads and temperatures. The analytical and experimental studies described in this paper provide a portion of the basic information required for the development of light-weight reusable cryogenic propellant tanks.

Thermal Structures Technology Development for Reusable Launch Vehicle Cryogenic Propellant Tanks

NASA Technical Reports Server (NTRS)

Johnson, Theodore F.; Natividad, Roderick; Rivers, H. Kevin; Smith, Russell W.

2005-01-01

Analytical and experimental studies conducted at the NASA, Langley Research Center (LaRC) for investigating integrated cryogenic propellant tank systems for a reusable launch vehicle (RLV) are described. The cryogenic tanks are investigated as an integrated tank system. An integrated tank system includes the tank wall, cryogenic insulation, thermal protection system (TPS) attachment sub-structure, and TPS. Analysis codes are used to size the thicknesses of cryogenic insulation and TPS insulation for thermal loads, and to predict tank buckling strengths at various ring frame spacings. The unique test facilities developed for the testing of cryogenic tank components are described. Testing at cryogenic and high-temperatures verifies the integrity of materials, design concepts, manufacturing processes, and thermal/structural analyses. Test specimens ranging from the element level to the subcomponent level are subjected to projected vehicle operational mechanical loads and temperatures. The analytical and experimental studies described in this paper provide a portion of the basic information required for the development of light-weight reusable cryogenic propellant tanks.

Feasibility study for a Cryogenic On-Orbit Liquid Depot-Storage, Acquisition and Transfer (COLD-SAT) satellite

NASA Technical Reports Server (NTRS)

Rybak, S. C.; Willen, G. S.; Follett, W. H.; Hanna, G. J.; Cady, E. C.; Distefano, E.; Meserole, J. S.

1990-01-01

This feasibility study presents the conceptual design of a spacecraft for performing a series of cryogenic fluid management flight experiments. This spacecraft, the Cryogenic On-Orbit Liquid Depot-Storage, Acquisition, and Transfer (COLD-SAT) satellite, will use liquid hydrogen as the test fluid, be launched on a Delta expendable launch vehicle, and conduct a series of experiments over a two to three month period. These experiments will investigate the physics of subcritical cryogens in the low gravity space environment to characterize their behavior and to correlate the data with analytical and numerical models of in-space cryogenic fluid management systems. Primary technologies addressed by COLD-SAT are: (1) pressure control; (2) chilldown; (3) no-vent fill; (4) liquid acquisition device fill; (5) pressurization; (6) low-g fill and drain; (7) liquid acquisition device expulsion; (8) line chilldown; (9) thermodynamic state control; and (10) fluid dumping.

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.

Cryogen-free operation of the Soft X-ray Spectrometer instrument

NASA Astrophysics Data System (ADS)

Sneiderman, Gary A.; Shirron, Peter J.; Fujimoto, Ryuichi; Bialas, Thomas G.; Boyce, Kevin R.; Chiao, Meng P.; DiPirro, Michael J.; Eckart, Megan E.; Hartz, Leslie; Ishisaki, Yoshitaka; Kelley, Richard L.; Kilbourne, Caroline A.; Masters, Candace; McCammon, Dan; Mitsuda, Kazuhisa; Noda, Hirofumi; Porter, Frederick S.; Szymkowiak, Andrew E.; Takei, Yoh; Tsujimoto, Masahiro; Yoshida, Seiji

2016-07-01

The Soft X-ray Spectrometer (SXS) is the first space-based instrument to implement redundancy in the operation of a sub-Kelvin refrigerator. The SXS cryogenic system consists of a superfluid helium tank and a combination of Stirling and Joule-Thompson (JT) cryocoolers that support the operation of a 3-stage adiabatic demagnetization refrigerator (ADR). When liquid helium is present, the x-ray microcalorimeter detectors are cooled to their 50 mK operating temperature by two ADR stages, which reject their heat directly to the liquid at 1.1 K. When the helium is depleted, all three ADR stages are used to accomplish detector cooling while rejecting heat to the JT cooler operating at 4.5 K. Compared to the simpler helium mode operation, the cryogen-free mode achieves the same instrument performance by controlling the active cooling devices within the cooling system differently. These include the three ADR stages and four active heat switches, provided by NASA, and five cryocoolers, provided by JAXA. Development and verification details of this capability are presented within this paper and offer valuable insights into the challenges, successes, and lessons that can benefit other missions, particularly those employing cryogen-free cooling systems.

Research of the cold shield in cryogenic liquid storage

NASA Astrophysics Data System (ADS)

Chen, L. B.; Zheng, J. P.; Wu, X. L.; Cui, C.; Zhou, Y.; Wang, J. J.

2017-12-01

To realize zero boil-off storage of cryogenic liquids, a cryocooler that can achieve a temperature below the boiling point temperature of the cryogenic liquid is generally needed. Taking into account that the efficiency of the cryocooler will be higher at a higher operating temperature, a novel thermal insulation system using a sandwich container filled with cryogenic liquid with a higher boiling point as a cold radiation shield between the cryogenic tank and the vacuum shield in room temperature is proposed to reduce the electricity power consumption. A two-stage cryocooler or two separate cryocoolers are adopted to condense the evaporated gas from the cold shield and the cryogenic tank. The calculation result of a 55 liter liquid hydrogen tank with a liquid nitrogen shield shows that only 14.4 W of electrical power is needed to make all the evaporated gas condensation while 121.7 W will be needed without the liquid nitrogen shield.

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.

Cold Helium Gas Pressurization For Spacecraft Cryogenic Propulsion Systems

NASA Technical Reports Server (NTRS)

Morehead, Robert L.; Atwell. Matthew J.; Hurlbert, Eric A.; Melcher, J. C.

2017-01-01

To reduce the dry mass of a spacecraft pressurization system, helium pressurant may be stored at low temperature and high pressure to increase mass in a given tank volume. Warming this gas through an engine heat exchanger prior to tank pressurization both increases the system efficiency and simplifies the designs of intermediate hardware such as regulators, valves, etc. since the gas is no longer cryogenic. If this type of cold helium pressurization system is used in conjunction with a cryogenic propellant, though, a loss in overall system efficiency can be expected due to heat transfer from the warm ullage gas to the cryogenic propellant which results in a specific volume loss for the pressurant, interpreted as the Collapse Factor. Future spacecraft with cryogenic propellants will likely have a cold helium system, with increasing collapse factor effects as vehicle sizes decrease. To determine the collapse factor effects and overall implementation strategies for a representative design point, a cold helium system was hotfire tested on the Integrated Cryogenic Propulsion Test Article (ICPTA) in a thermal vacuum environment at the NASA Glenn Research Center Plum Brook Station. The ICPTA vehicle is a small lander-sized spacecraft prototype built at NASA Johnson Space Center utilizing cryogenic liquid oxygen/liquid methane propellants and cryogenic helium gas as a pressurant to operate one 2,800lbf 5:1 throttling main engine, two 28lbf Reaction Control Engines (RCE), and two 7lbf RCEs (Figure 1). This vehicle was hotfire tested at a variety of environmental conditions at NASA Plum Brook, ranging from ambient temperature/simulated high altitude, deep thermal/high altitude, and deep thermal/high vacuum conditions. A detailed summary of the vehicle design and testing campaign may be found in Integrated Cryogenic Propulsion Test Article Thermal Vacuum Hotfire Testing, AIAA JPC 2017.

Active Thermal Architecture for Cryogenic Optical Instrumentation (ATACOI)

NASA Technical Reports Server (NTRS)

Swenson, Charles; Hunter, Roger C.; Baker, Christopher E.