Sample records for jordana jet propulsion

  1. Jet propulsion without inertia

    E-Print Network [OSTI]

    Saverio E. Spagnolie; Eric Lauga

    2010-05-04T23:59:59.000Z

    A body immersed in a highly viscous fluid can locomote by drawing in and expelling fluid through pores at its surface. We consider this mechanism of jet propulsion without inertia in the case of spheroidal bodies, and derive both the swimming velocity and the hydrodynamic efficiency. Elementary examples are presented, and exact axisymmetric solutions for spherical, prolate spheroidal, and oblate spheroidal body shapes are provided. In each case, entirely and partially porous (i.e. jetting) surfaces are considered, and the optimal jetting flow profiles at the surface for maximizing the hydrodynamic efficiency are determined computationally. The maximal efficiency which may be achieved by a sphere using such jet propulsion is 12.5%, a significant improvement upon traditional flagella-based means of locomotion at zero Reynolds number. Unlike other swimming mechanisms which rely on the presentation of a small cross section in the direction of motion, the efficiency of a jetting body at low Reynolds number increases as the body becomes more oblate, and limits to approximately 162% in the case of a flat plate swimming along its axis of symmetry. Our results are discussed in the light of slime extrusion mechanisms occurring in many cyanobacteria.

  2. Strategic Technology JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Waliser, Duane E.

    Strategic Technology Directions JET PROPULSION LABORATORY National Aeronautics and Space Administration 2 0 0 9 #12;© 2009 California Institute of Technology. Government sponsorship acknowledged. #12;Strategic Technology Directions 2009 offers a distillation of technologies, their links to space missions

  3. MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Christian, Eric

    MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL FROM SHATTERED STAR The signal of a cataclysmic magnetic flare emanating from a star that cracked apart about some of the most unusual stars in the universe. The magnetic burst from the star SGR1900

  4. PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Christian, Eric

    PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL are above the current sheet, they detect magnetic fields directed outward from the sun. When spacecraft observing magnetic field lines pointing inward only," Marsden said. A pair of magnetometers, each able

  5. JET PROPULSION LAB 0 RAT 0 R Y

    E-Print Network [OSTI]

    Waliser, Duane E.

    JET PROPULSION LAB 0 RAT 0 R Y ANN U A L REP 0 R T #12;#12;------ - - ~ CON TEN T S DIRECTOR Administration for the penod January 1 through December 31, 1986. JET PROPULSION LABORATORY Califorrua Institute, Voyager 2 gave us our first close view of the distant giant Uranus, its complex rings, inclined magnetic

  6. 1Pre-Decisional --For Planning and Discussion Purposes Only. Copyright 2013. All rights reserved. 1Jet Propulsion Laboratory,

    E-Print Network [OSTI]

    Rathbun, Julie A.

    . 1Jet Propulsion Laboratory, California Institute of Technology 2Applied Physics Laboratory, Johns Propulsion Laboratory (JPL) and Johns Hopkins University's Applied Physics Laboratory (APL). The team and the structure of the icy shell. IO.2 Determine Europa's magnetic induction response to estimate ocean salinity

  7. A Model-Driven Architecture for Highly Distributed, Data-Intensive Systems Jet Propulsion Laboratory, May 2008

    E-Print Network [OSTI]

    Mattmann, Chris

    from unstructured and semi-structure information (ii) Scalable, secure, federated search (iii The Jet Propulsion Laboratory (JPL) has been researching and building data intensive systems for highly for both solar system and earth exploration, these systems have a number of critical architectural

  8. An investigation of the entrainment effects of a propulsive jet on the base pressure of blunt based bodies

    E-Print Network [OSTI]

    Berry, Ronald Allen

    1973-01-01T23:59:59.000Z

    and Henderson did a parameter correlation of data on 6 the effect of the supersonic power on base drag, using some obser- vations of Cubbsge . This correlation dealt only with Phase 4. Three of the flow regime, and it resulted in a formula wh1ch pre- dicted... coefficient of a body with th1s base geometry, one must first determine the base pres- sure coefficient with no propulsive jet and then add. the delta base pressure coefficient interpolated from the cucves. Both the Brazzel and Henderson and Mc...

  9. Software Engineering for Space Exploration Iowa State University and Jet Propulsion Laboratory/California Institute of Technology

    E-Print Network [OSTI]

    Lutz, Robyn R.

    and Techniques, D.2.4.g Reliability, D.2.7 Distribution, Maintenance and Enhancement, D.2.15 Software and System Safety. 1. Software engineering plays a vital role in space exploration Innovations in robotic spacecraft1 Software Engineering for Space Exploration Robyn Lutz Iowa State University and Jet

  10. JET PROPULSION LABORATORY COVER: FROM

    E-Print Network [OSTI]

    Waliser, Duane E.

    "G UVER 155 Bl;JLDI:-JGS. 1:-1 THIS PA:-IORAMIC VIEW, THE SA=-- GAB- IUEL ,\\I011NTr\\J:-I~ I'Ot{.\\1 A Mi in the robotic explnration ofthe solarsystem:As a NASA Jteld center, JPL is charged with responsibilityfor a l7lVad range ofmajor robotic planetary missions and space science instruments. .. The advancement ofscientific

  11. Advanced Propulsion Technology Strategy

    Broader source: Energy.gov (indexed) [DOE]

    Alternative Sources) Hydrogen Time ADVANCED PROPULSION TECHNOLOGY STRATEGY DOWNSIZED TURBO GAS ENGINE CHEVROLET CRUZE 1.4L TURBO ECOTEC Downsized SIDI Turbo Boosting HCCI -...

  12. 7PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Christian, Eric

    , as a result of efforts by the joint NASA-ESA mission operations team and NASA's Deep Space Network. Although degrees, scientists on the joint NASA-European Space Agency (ESA) mission reported. "Ulysses is gathering important new information about the sun and its environment as it continues to journey farther south toward

  13. PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Christian, Eric

    Force Operational Test and Evaluation Center, assigned to the Los Angeles Air Force Base, Calif. Before in the Space Defense Systems Air Force Space Division, Los Angeles Air Force Base, Calif. In his earlier Air communications and scientific data collection for the highly productive Ulysses mission, a joint mission of NASA

  14. PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY

    E-Print Network [OSTI]

    Christian, Eric

    , velocity and turbulence of the solar atmosphere. Dr. Michael Bird of the University of Bonn, Germany from Ulysses will pass close to the sun's surface and travel through the dense lower solar atmosphere," Page said. At closest approach, the signals will cross through 1 #12;the sun's corona at four solar

  15. Antonio Diaz-Calderon Jet Propulsion Laboratory

    E-Print Network [OSTI]

    Kelly, Alonzo

    @jpl.nasa.gov Alonzo Kelly The Robotics Institute Carnegie Mellon University On-Line Stability Margin and Attitude which move heavy loads, accelerate or brake aggressively, turn at speed, or operate on sloped terrain

  16. Cover: Mariner 9 spacecraft. JET PROPULSION

    E-Print Network [OSTI]

    Waliser, Duane E.

    programs included a police air patrol system, a school alarm system, monitoring systems for hos- pitals, and studies of water pollution and energy management. In general, 1971 was a year of solid ac- complishment following gravity acceleration from the field of Venus. The spacecraft system design was essentially

  17. ECR-GDM Thruster for Fusion Propulsion

    SciTech Connect (OSTI)

    Brainerd, Jerome J.; Reisz, Al [Reisz Engineers 2909 Johnson Rd. Huntsville, Alabama 35805 256-325-2531 (United States)

    2009-03-16T23:59:59.000Z

    The concept of the Gasdynamic Mirror (GDM) device for fusion propulsion was proposed by and Lee (1995) over a decade ago and several theoretical papers has supported the feasibility of the concept. A new ECR plasma source has been built to supply power to the GDM experimental thruster previously tested at the Marshall Space Flight Center (MSFC). The new plasma generator, powered by microwaves at 2.45 or 10 GHz. is currently being tested. This ECR plasma source operates in a number of distinct plasma modes, depending upon the strength and shape of the local magnetic field. Of particular interest is the compact plasma jet issuing form the plasma generator when operated in a mirror configuration. The measured velocity profile in the jet plume is bimodal, possibly as a result of the GDM effect in the ECR chamber of the thruster.

  18. Progress in colloid propulsion

    E-Print Network [OSTI]

    López Urdiales, Jóse Mariano, 1977-

    2004-01-01T23:59:59.000Z

    In the early decades of the Space Age, a great deal of work was put into the development of the Colloid Thruster as an electric propulsion system for spacecraft. In spite of the effort by the end of the 70s the programs ...

  19. Propulsion engineering study for small-scale Mars missions

    SciTech Connect (OSTI)

    Whitehead, J.

    1995-09-12T23:59:59.000Z

    Rocket propulsion options for small-scale Mars missions are presented and compared, particularly for the terminal landing maneuver and for sample return. Mars landing has a low propulsive {Delta}v requirement on a {approximately}1-minute time scale, but at a high acceleration. High thrust/weight liquid rocket technologies, or advanced pulse-capable solids, developed during the past decade for missile defense, are therefore more appropriate for small Mars landers than are conventional space propulsion technologies. The advanced liquid systems are characterize by compact lightweight thrusters having high chamber pressures and short lifetimes. Blowdown or regulated pressure-fed operation can satisfy the Mars landing requirement, but hardware mass can be reduced by using pumps. Aggressive terminal landing propulsion designs can enable post-landing hop maneuvers for some surface mobility. The Mars sample return mission requires a small high performance launcher having either solid motors or miniature pump-fed engines. Terminal propulsion for 100 kg Mars landers is within the realm of flight-proven thruster designs, but custom tankage is desirable. Landers on a 10 kg scale also are feasible, using technology that has been demonstrated but not previously flown in space. The number of sources and the selection of components are extremely limited on this smallest scale, so some customized hardware is required. A key characteristic of kilogram-scale propulsion is that gas jets are much lighter than liquid thrusters for reaction control. The mass and volume of tanks for inert gas can be eliminated by systems which generate gas as needed from a liquid or a solid, but these have virtually no space flight history. Mars return propulsion is a major engineering challenge; earth launch is the only previously-solved propulsion problem requiring similar or greater performance.

  20. Lightweighting and Propulsion Materials Roadmapping Workshop...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Lightweighting and Propulsion Materials Roadmapping Workshop Outbrief Lightweighting and Propulsion Materials Roadmapping Workshop Outbrief 2012 DOE Hydrogen and Fuel Cells Program...

  1. Nuclear Propulsion in Space (1968)

    ScienceCinema (OSTI)

    None

    2014-06-17T23:59:59.000Z

    Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.

  2. Nuclear Propulsion in Space (1968)

    SciTech Connect (OSTI)

    None

    2012-06-23T23:59:59.000Z

    Project NERVA was an acronym for Nuclear Engine for Rocket Vehicle Application, a joint program of the U.S. Atomic Energy Commission and NASA managed by the Space Nuclear Propulsion Office (SNPO) at the Nuclear Rocket Development Station in Jackass Flats, Nevada U.S.A. Between 1959 and 1972, the Space Nuclear Propulsion Office oversaw 23 reactor tests, both the program and the office ended at the end of 1972.

  3. Performance and Emission Characteristics of an Aircraft Turbo Diesel Engine using JET-A Fuel

    E-Print Network [OSTI]

    Underwood, Sean Christopher

    2008-05-05T23:59:59.000Z

    Performance and emission data was acquired by testing an aircraft turbo diesel engine with JET-A at the Mal Harned Propulsion Laboratory of the University of Kansas. The performance data was analyzed and compared to the presented data...

  4. Lagrangian simulation of transverse jets with a distribution-based diffusion scheme

    E-Print Network [OSTI]

    Wee, Daehyun, 1974-

    2007-01-01T23:59:59.000Z

    Transverse jets form a dominant group of flow fields arising in many applications of modern energy utilization, including propulsion and effluent dispersion. Furthermore, they form canonical examples where the flow field ...

  5. Vorticity structure and evolution in a transverse jet with new algorithms for scalable particle simulation

    E-Print Network [OSTI]

    Marzouk, Youssef M. (Youssef Mohamed)

    2004-01-01T23:59:59.000Z

    Transverse jets arise in many applications, including propulsion, effluent dispersion, oil field flows, V/STOL aerodynamics, and drug delivery. Furthermore, they exemplify flows dominated by coherent structures that cascade ...

  6. Elastic tail propulsion at low Reynolds number

    E-Print Network [OSTI]

    Yu, Tony S. (Tony Sheung)

    2007-01-01T23:59:59.000Z

    A simple way to generate propulsion at low Reynolds number is to periodically oscillate a passive flexible filament. Here we present a macroscopic experimental investigation of such a propulsive mechanism. A robotic swimmer ...

  7. Jet Propulsion Laboratory 1972-1973 Annual Report

    E-Print Network [OSTI]

    Waliser, Duane E.

    for the im- provement of internal combustion engine performance. There has been growing collaboration- sector agencies has expanded. Develop- ment of a low-pollution engine concept holds considerable promise

  8. SUNITA PAYRA VERMA Jet Propulsion Laboratory, California Institute of Technology

    E-Print Network [OSTI]

    Associate · In project entitled "Scale up to obtain super clean coal - Organo-refining and identification

  9. Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers Ian K. Bartol, Paul S. Krueger, William J. Stewart and Joseph T. Thompson

    E-Print Network [OSTI]

    Hynes, Wayne L.

    Pulsed jet dynamics of squid hatchlings at intermediate Reynolds numbers Ian K. Bartol, Paul S of various appendages, squid paralarvae (hatchlings) employ a pulsed jet for locomotion at intermediate Re different propulsive mechanism, i.e. jetting, involves (1) radial expansion of the mantle, resulting

  10. Stellar jets

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2008-05-23T23:59:59.000Z

    With a goal of understanding the conditions under which jets might be produced in novae and related objects, I consider the conditions under which jets are produced from other classes of accreting compact objects. I give an overview of accretion disk spectral states, including a discussion of in which states these jets are seen. I highlight the differences between neutron stars and black holes, which may help give us insights about when and how the presence of a solid surface may help or inhibit jet production.

  11. Life Cycle Modeling of Propulsion Materials

    Broader source: Energy.gov (indexed) [DOE]

    * Start - Oct. 2008 * Finish - Sept. 2010 & beyond * 10% Complete for FY10 Budget * Total project funding - 80Kyear (FY'09) - 185K (FY'10) Barriers * Advanced propulsion...

  12. Pure Nuclear Fusion Bomb Propulsion

    E-Print Network [OSTI]

    Winterberg, F

    2008-01-01T23:59:59.000Z

    Recent progress towards the non-fission ignition of thermonuclear micro-explosions raises the prospect for a revival of the nuclear bomb propulsion idea, both for the fast transport of large payloads within the solar system and the launch into earth orbit without the release of fission products into the atmosphere. To reach this goal three areas of research are of importance: 1)Compact thermonuclear ignition drivers. 2)Fast ignition and deuterium burn. 3)Space-craft architecture involving magnetic insulation and GeV electrostatic potentials

  13. Enabling Green Energy and Propulsion Systems via Direct Noise...

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

    GE propulsion systems Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI Email: paliath@ge.com Institution: GE Global Research...

  14. air independent propulsion: Topics by E-print Network

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

    Electric Propulsion Conference, The George Washington University, USA October 6 10, 2013 Engineering Websites Summary: The 33st International Electric Propulsion...

  15. Vehicle Technologies Office: 2010 Propulsion Materials R&D Annual...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    0 Propulsion Materials R&D Annual Progress Report Vehicle Technologies Office: 2010 Propulsion Materials R&D Annual Progress Report 2010 annual progress report focusing on enabling...

  16. Vehicle Technologies Office: 2008 Propulsion Materials R&D Annual...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8 Propulsion Materials R&D Annual Progress Report Vehicle Technologies Office: 2008 Propulsion Materials R&D Annual Progress Report 2008propulsionmaterials.pdf More Documents &...

  17. Vehicle Technologies Office: 2011 Propulsion Materials R&D Annual...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vehicle Technologies Office: 2011 Propulsion Materials R&D Annual Progress Report Vehicle Technologies Office: 2011 Propulsion Materials R&D Annual Progress Report 2011 annual...

  18. 2008 Annual Merit Review Results Summary - 12. Propulsion Materials

    Broader source: Energy.gov (indexed) [DOE]

    2-1 12. Propulsion Materials Introduction Propulsion materials research is critical to bringing advanced high-efficiency powertrains to the marketplace. The use of innovative...

  19. Vehicle Technologies Office: 2013 Propulsion Materials R&D Annual...

    Energy Savers [EERE]

    3 Propulsion Materials R&D Annual Progress Report Vehicle Technologies Office: 2013 Propulsion Materials R&D Annual Progress Report This report describes the progress made during...

  20. advanced space propulsion: Topics by E-print Network

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

    12 NASA Procedural Requirements NRPTA National Rocket Propulsion Testing Alliance OIG Office of Inspector General RPT Rocket Propulsion Test SLS Space Launch System...

  1. advanced electric propulsion: Topics by E-print Network

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

    distant electric propulsion missions ... Goycoolea, Martin 2013-01-01 7 Simplest AB-Thermonuclear Space Propulsion and Electric Generator CERN Preprints Summary: The author...

  2. Vehicle Technologies Office: 2008 Propulsion Materials R&D Annual...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Vehicle Technologies Office: 2008 Propulsion Materials R&D Annual Progress Report Vehicle Technologies Office: 2008 Propulsion Materials R&D Annual Progress Report...

  3. Jet observables without jet algorithms

    E-Print Network [OSTI]

    Bertolini, Daniele

    We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but ...

  4. Propulsive Efficiency of Rowing Oars David S. Cabrera1

    E-Print Network [OSTI]

    Ruina, Andy L.

    Propulsive Efficiency of Rowing Oars David S. Cabrera1 Andy L. Ruina2 Department of Theoretical Is the common folklore, that oars are less efficient at propulsion than propellers, correct? Here we examine the propulsive efficiency of the oars used in competitive rowing. We take the propulsive efficiency of rowing

  5. Propulsion mechanisms in a helicon plasma thruster

    E-Print Network [OSTI]

    Sinenian, Nareg

    2008-01-01T23:59:59.000Z

    Electric thrusters offer an attractive option for various in-space propulsion tasks due to their high thrust efficiencies. The performance characteristics of a compact electric thruster utilizing a helicon plasma source ...

  6. http://lez1.pppl.gov/pub/LiMagPropulsion.ps http://lez1.pppl.gov/pub/LiMagPropulsion.pdf

    E-Print Network [OSTI]

    Zakharov, Leonid E.

    http://lez1.pppl.gov/pub/LiMagPropulsion.ps http://lez1.pppl.gov/pub/LiMagPropulsion.pdf Magnetic propulsion for driving liquid Li walls L. E. Zakharov, PPPL Background: The mechanism of magnetic propulsion the technical aspects of magnetic propulsion, the issues and the necessary R & D. Electro-magnetic propulsion

  7. Jet Shapes and Jet Algorithms in SCET

    E-Print Network [OSTI]

    Stephen D. Ellis; Andrew Hornig; Christopher Lee; Christopher K. Vermilion; Jonathan R. Walsh

    2010-11-15T23:59:59.000Z

    Jet shapes are weighted sums over the four-momenta of the constituents of a jet and reveal details of its internal structure, potentially allowing discrimination of its partonic origin. In this work we make predictions for quark and gluon jet shape distributions in N-jet final states in e+e- collisions, defined with a cone or recombination algorithm, where we measure some jet shape observable on a subset of these jets. Using the framework of Soft-Collinear Effective Theory, we prove a factorization theorem for jet shape distributions and demonstrate the consistent renormalization-group running of the functions in the factorization theorem for any number of measured and unmeasured jets, any number of quark and gluon jets, and any angular size R of the jets, as long as R is much smaller than the angular separation between jets. We calculate the jet and soft functions for angularity jet shapes \\tau_a to one-loop order (O(alpha_s)) and resum a subset of the large logarithms of \\tau_a needed for next-to-leading logarithmic (NLL) accuracy for both cone and kT-type jets. We compare our predictions for the resummed \\tau_a distribution of a quark or a gluon jet produced in a 3-jet final state in e+e- annihilation to the output of a Monte Carlo event generator and find that the dependence on a and R is very similar.

  8. Haar LBP Gabor Jet boosting Gabor Jet

    E-Print Network [OSTI]

    Ai, Haizhou

    Boosting 1 boosting Haar LBP Gabor Jet boosting LBP Haar Gabor Jet boosting TP391. Further more, three kinds of local feature, Haar like feature, LBP histogram and Gabor jet are extracted, Haar like feature is more efficient for discriminating young and middle aged people, and Gabor Jet fits

  9. Space Propulsion Field Exam: Space Propulsion/Plasma Physics REQUIRED BY ALL STUDENTS

    E-Print Network [OSTI]

    de Weck, Olivier L.

    Space Propulsion Field Exam: Space Propulsion/Plasma Physics REQUIRED BY ALL STUDENTS From) Both devices use magnetic fields, even though they both are electrostatic ion accelerators. Explain the role of the magnetic field in each of them, and how this guides the layout of these fields. 3) One

  10. DICHOTOMY OF SOLAR CORONAL JETS: STANDARD JETS AND BLOWOUT JETS

    SciTech Connect (OSTI)

    Moore, Ronald L.; Cirtain, Jonathan W.; Sterling, Alphonse C.; Falconer, David A., E-mail: ron.moore@nasa.go [Space Science Office, VP62, Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2010-09-01T23:59:59.000Z

    By examining many X-ray jets in Hinode/X-Ray Telescope coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H{alpha} macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major coronal mass ejections. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 A snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T {approx} 10{sup 4} - 10{sup 5} K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  11. Nuclear thermal propulsion engine cost trade studies

    SciTech Connect (OSTI)

    Paschall, R.K. (Rocketdyne Division, Rockwell International Corporation, Mail Stop IB57, 6633 Canoga Avenue, P.O. Box 7922, Canoga Park, California 91309-7922 (United States))

    1993-01-10T23:59:59.000Z

    The NASA transportation strategy for the Mars Exploration architecture includes the use of nuclear thermal propulsion as the primary propulsion system for Mars transits. It is anticipated that the outgrowth of the NERVA/ROVER programs will be a nuclear thermal propulsion (NTP) system capable of providing the propulsion for missions to Mars. The specific impulse (Isp) for such a system is expected to be in the 870 s range. Trade studies were conducted to investigate whether or not it may be cost effective to invest in a higher performance (Isp[gt]870 s) engine for nuclear thermal propulsion for missions to Mars. The basic cost trades revolved around the amount of mass that must be transported to low-earth orbit prior to each Mars flight and the cost to launch that mass. The mass required depended on the assumptions made for Mars missions scenarios including piloted/cargo flights, number of Mars missions, and transit time to Mars. Cost parameters included launch cost, program schedule for development and operations, and net discount rate. The results were very dependent on the assumptions that were made. Under some assumptions, higher performance engines showed cost savings in the billions of dollars; under other assumptions, the additional cost to develop higher performance engines was not justified.

  12. DC, AC and advanced EV propulsion systems

    SciTech Connect (OSTI)

    O'Neil, W.

    1983-08-01T23:59:59.000Z

    Battery development and liquid fuel availability and cost are still the pacing factors in wide scale electric vehicle introduction. Propulsion systems also require technical development, however, if electric vehicles are to be acceptable in the marketplace in competition against ICE vehicles. Eaton Corporation has undertaken a program designed to identify and investigate three broad types of propulsion systems in identical test vehicles on the same test track under conditions as similar as possible. Characteristics of dc, ac and advanced systems are compared to date, and projections of anticipated results and further work are provided. The compelling advantages of multiple mechanical ratios in EV propulsion systems are reviewed. An emerging, but less obvious, advantage is higher overall system efficiency.

  13. Jet finding techniques at LHC

    E-Print Network [OSTI]

    BOUMEDIENE, D; The ATLAS collaboration

    2015-01-01T23:59:59.000Z

    Jet finding techniques at hadron colliders, including pile-up removal tricks, jet deconstruction, etc

  14. Boston University Physics Colloquium Microscale propulsion in biological and

    E-Print Network [OSTI]

    Mohanty, Raj

    Boston University Physics Colloquium Microscale propulsion in biological and engineered systems biological locomotion and engineered propulsion. In the first example, we examine swimming microorganisms the microstructure. In the second example, we examine engineered magnetic artificial microswimmers which can

  15. Experimental Investigations of Elastic Tail Propulsion At Low Reynolds Number

    E-Print Network [OSTI]

    Yu, Tony S.

    2007-05-04T23:59:59.000Z

    A simple way to generate propulsion at low Reynolds number is to periodically oscillate a passive flexible filament. Here we present a macroscopic experimental investigation of such a propulsive mechanism. A robotic swimmer ...

  16. A development approach for nuclear thermal propulsion

    SciTech Connect (OSTI)

    Buden, D.

    1992-09-01T23:59:59.000Z

    The cost and time to develop nuclear thermal propulsion systems are very approach dependent. The objectives addressed are the development of an ``acceptable`` nuclear thermal propulsion system that can be used as part of the transportation system for people to explore Mars and the enhancement performance of other missions, within highly constrained budgets and schedules. To accomplish this, it was necessary to identify the cost drivers considering mission parameters, safety of the crew, mission success, facility availability and time and cost to construct new facilities, qualification criteria, status of technologies, management structure, and use of such system engineering techniques as concurrent engineering.

  17. A development approach for nuclear thermal propulsion

    SciTech Connect (OSTI)

    Buden, D.

    1992-01-01T23:59:59.000Z

    The cost and time to develop nuclear thermal propulsion systems are very approach dependent. The objectives addressed are the development of an acceptable'' nuclear thermal propulsion system that can be used as part of the transportation system for people to explore Mars and the enhancement performance of other missions, within highly constrained budgets and schedules. To accomplish this, it was necessary to identify the cost drivers considering mission parameters, safety of the crew, mission success, facility availability and time and cost to construct new facilities, qualification criteria, status of technologies, management structure, and use of such system engineering techniques as concurrent engineering.

  18. Propulsive Efficiency of the Underwater Dolphin Kick in Humans

    E-Print Network [OSTI]

    Fish, Frank

    Propulsive Efficiency of the Underwater Dolphin Kick in Humans Alfred von Loebbecke Rajat Mittal's propulsive efficiencies. These estimates are compared with those of a ceta- cean performing the dolphin kick kinematics is based on underwater video footage. The simulations indicate that the propulsive efficiency

  19. Magnetic propulsion of liquid Li in tokamaks 1

    E-Print Network [OSTI]

    Zakharov, Leonid E.

    Magnetic propulsion of liquid Li in tokamaks 1 Leonid E. Zakharov, Princeton University, Princeton of the torus. This effect of magnetic propulsion can be used for developing new approaches for protecting circumference. On the other hand, when the liquid lithium is held in a closed volume, magnetic propulsion

  20. PROPULSION AND ENERGY 54 AEROSPACE AMERICA/DECEMBER 2005

    E-Print Network [OSTI]

    Walker, Mitchell

    PROPULSION AND ENERGY 54 AEROSPACE AMERICA/DECEMBER 2005 Electric propulsion Several significant advancements in electric propulsion (EP) systems and related technolo- gies occurred this year. Flight programs throughout the discharge and includes the effects of magnetic fields on the primary electrons. PRIMA is used

  1. From Jet Counting to Jet Vetoes

    E-Print Network [OSTI]

    Peter Schichtel; Christoph Englert; Erik Gerwick; Tilman Plehn; Steffen Schumann

    2012-06-04T23:59:59.000Z

    The properties of multi-jet events impact many LHC analysis. The exclusive number of jets at hadron colliders can be described in terms of two simple patterns: staircase scaling and Poisson scaling. In photon plus jets production we can interpolate between the two patterns using simple kinematic cuts. The associated theoretical errors are well under control. Understanding such exclusive jet multiplicities significantly impacts Higgs searches and searches for supersymmetry at the LHC.

  2. Propulsion in a viscoelastic fluid Eric Laugaa

    E-Print Network [OSTI]

    Lauga, Eric

    and a healthy respiratory system.8 Cilia are short flagella which produce fluid motion by means mechanisms and propulsion.9 In the upper respiratory tract, cilia are located in a thin layer of low influenced by viscoelastic stresses. Relevant examples include the ciliary transport of respiratory airway

  3. MHD (magnetohydrodynamic) undersea propulsion: A novel concept with renewed interest

    SciTech Connect (OSTI)

    Doss, E.D.; Geyer, H.K. (Argonne National Lab., IL (USA)); Roy, G.D. (Office of Naval Research, Arlington, VA (USA))

    1990-01-01T23:59:59.000Z

    This paper discusses the reasons for the national and international renewed interest in the concept of MHD seawater propulsion. The main advantages of this concept are presented, together with some of the technical challenges that need to be overcome to achieve reliability, performance, and stealth. The paper discusses in more detail some of the technical issues and loss mechanisms influencing the thruster performance in terms of its electrical efficiency. Among the issues discussed are the jet losses and nozzle efficiency. Ohmic losses and frictional losses inside the thruster. Also discussed are the electrical end losses caused by the fringing magnetic field near the end of the electrodes. It has been shown that the frictional and end losses can have strong adverse effects on the thruster performance. Furthermore, a parametric study has been performed to investigate the effects of several parameters on the performance of the MHD thrusters. Those parameters include the magnetic field, thruster diameter, all roughness, flow velocity, and electrical load factor. The results of the parametric study indicate that the thruster efficiency increases with the strength of the magnetic field and thruster diameter, and decreases with the wall roughness and the flow velocity. 8 refs., 8 figs.

  4. Nuclear Thermal Propulsion: A Joint NASA/DOE/DOD Workshop

    SciTech Connect (OSTI)

    Clark, J.S.

    1991-01-01T23:59:59.000Z

    Papers presented at the joint NASA/DOE/DOD workshop on nuclear thermal propulsion are compiled. The following subject areas are covered: nuclear thermal propulsion programs; Rover/NERVA and NERVA systems; Low Pressure Nuclear Thermal Rocket (LPNTR); particle bed reactor nuclear rocket; hybrid propulsion systems; wire core reactor; pellet bed reactor; foil reactor; Droplet Core Nuclear Rocket (DCNR); open cycle gas core nuclear rockets; vapor core propulsion reactors; nuclear light bulb; Nuclear rocket using Indigenous Martian Fuel (NIMF); mission analysis; propulsion and reactor technology; development plans; and safety issues.

  5. Jet Reconstruction at RHIC

    E-Print Network [OSTI]

    Sevil Salur; for the STAR Collaboration

    2010-05-14T23:59:59.000Z

    Full jet reconstruction in heavy-ion collisions is expected to provide more sensitive measurements of jet quenching in hot QCD matter at RHIC. In this paper we review recent studies of jets utilizing modern jet reconstruction algorithms and their corresponding background subtraction techniques.

  6. Jet Physics at CDF

    E-Print Network [OSTI]

    Kenichi Hatakeyama; for the CDF Collaboration

    2007-12-12T23:59:59.000Z

    Recent results on jet physics at the Fermilab Tevatron $p\\bar p$ collider from the CDF Collaboration are presented. The main focus is put on results for the inclusive jet and dijet, $b\\bar b$ dijet, $W/Z+$jets and $W/Z+b$-jets production.

  7. Fluidic electrodynamics: Approach to electromagnetic propulsion

    SciTech Connect (OSTI)

    Martins, Alexandre A.; Pinheiro, Mario J. [Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 351.1.21.841.92.43 (Portugal); Department of Physics and Institute for Plasmas and Nuclear Fusion and Instituto Superior Tecnico Lisboa, Portugal 351.1.21.841.93.22 (Portugal)

    2009-03-16T23:59:59.000Z

    We report on a new methodological approach to electrodynamics based on a fluidic viewpoint. We develop a systematic approach establishing analogies between physical magnitudes and isomorphism (structure-preserving mappings) between systems of equations. This methodological approach allows us to give a general expression for the hydromotive force, thus re-obtaining the Navier-Stokes equation departing from the appropriate electromotive force. From this ground we offer a fluidic approach to different kinds of issues with interest in propulsion, e.g., the force exerted by a charged particle on a body carrying current; the magnetic force between two parallel currents; the Magnus's force. It is shown how the intermingle between the fluid vector fields and electromagnetic fields leads to new insights on their dynamics. The new concepts introduced in this work suggest possible applications to electromagnetic (EM) propulsion devices and the mastery of the principles of producing electric fields of required configuration in plasma medium.

  8. Fast Track'' nuclear thermal propulsion concept

    SciTech Connect (OSTI)

    Johnson, R.A.; Zweig, H.R. (Rocketdyne Division, Rockwell International Corporation, 6633 Canoga Avenue, P.O. Box 7922, Canoga Park, California 91309-7922 (United States)); Cooper, M.H.; Wett, J. Jr. (Westinghouse Electric Corporation, Post Office Box 158, Madison, Pennsylvania 15663 (United States))

    1993-01-10T23:59:59.000Z

    The objective of the Space Exploration Initiative ( America at the Threshold...,'' 1991) is the exploration of Mars by man in the second decade of the 21st century. The NASA Fast Track'' approach (NASA-LeRC Presentation, 1992) could accelerate the manned exploration of Mars to 2007. NERVA-derived nuclear propulsion represents a viable near-term technology approach to accomplish the accelerated schedule. Key milestones in the progression to the manned Mars mission are (1) demonstration of TRL-6 for the man-rateable system by 1999, (2) a robotic lunar mission by 2000, (3) the first cargo mission to Mars by 2005, and (4) the piloted Mars mission in 2007. The Rocketdyne-Westinghouse concept for nuclear thermal propulsion to achieve these milestones combines the nuclear reactor technology of the Rover/NERVA programs and the state-of-the-art hardware designs from hydrogen-fueled rocket engine successes like the Space Shuttle Main Engine (SSME).

  9. SERAPHIM: A propulsion technology for fast trains

    SciTech Connect (OSTI)

    Kelly, B.; Turman, B.; Marder, B.; Rohwein, G.; Aeschliman, D.; Cowan, B.

    1995-06-01T23:59:59.000Z

    The Segmented Rail Phased Induction Motor (SERAPHIM) is a compact, pulsed linear induction motor (LIM) offering a unique capability for very high speed train propulsion. It uses technology developed for the Sandia coilgun, an electromagnetic launcher designed to accelerate projectiles to several kilometers per second. Both aluminum cylinders and plates were accelerated to a kilometer per second (Mach 3) by passing through a sequence of coils which were energized at the appropriate time. Although this technology was developed for ultra-high velocity, it can be readily adapted to train propulsion for which, at sea level, the power required to overcome air resistance limits the operational speed to a more modest 300 mph. Here, the geometry is reversed. The coils are on the vehicle and the ``projectiles`` are fixed along the roadbed. SERAPHIM operates not by embedding flux in a conductor, but by excluding it. In this propulsion scheme, pairs of closely spaced coils on the vehicle straddle a segmented aluminum reaction rail. A high frequency current is switched on as a coil pair crosses an edge and remains off as they overtake the next segment. This induces surface currents which repel the coil. In essence, the pulsed coils push off segment edges because at the high frequency of operation, the flux has insufficient time to penetrate. In contrast to conventional LIMs, the performance actually improves with velocity, even for a minimal motor consisting of a single coil pair reacting with a single plate. This paper will present results of proof-of-principle tests, electromagnetic computer simulations, and systems analysis. It is concluded that this new linear induction motor can be implemented using existing technology and is a promising alternative propulsion method for very high speed rail transportation.

  10. Engineering Challenges in Antiproton Triggered Fusion Propulsion

    SciTech Connect (OSTI)

    Cassenti, Brice [Department. of Engineering and Science, Rensselaer Polytechnic Institute, 275 Windsor Avenue, Hattford, CT 06120 (United States); Kammash, Terry [Nuclear Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States)

    2008-01-21T23:59:59.000Z

    During the last decade antiproton triggered fusion propulsion has been investigated as a method for achieving high specific impulse, high thrust in a nuclear pulse propulsion system. In general the antiprotons are injected into a pellet containing fusion fuel with a small amount of fissionable material (i.e., an amount less than the critical mass) where the products from the fission are then used to trigger a fusion reaction. Initial calculations and simulations indicate that if magnetically insulated inertial confinement fusion is used that the pellets should result in a specific impulse of between 100,000 and 300,000 seconds at high thrust. The engineering challenges associated with this propulsion system are significant. For example, the antiprotons must be precisely focused. The pellet must be designed to contain the fission and initial fusion products and this will require strong magnetic fields. The fusion fuel must be contained for a sufficiently long time to effectively release the fusion energy, and the payload must be shielded from the radiation, especially the excess neutrons emitted, in addition to many other particles. We will review the recent progress, possible engineering solutions and the potential performance of these systems.

  11. High Pt Jet Physics

    E-Print Network [OSTI]

    M. Martinez

    2006-10-13T23:59:59.000Z

    In this contribution, a comprehensive review of the main aspects of high $\\pt$ jet physics in Run II at the Tevatron is presented. Recent measurements on inclusive jet production are discussed using different jet algorithms and covering a wide region of jet transverse momentum and jet rapidity. Several measurements, sensitive to a proper description of soft gluon radiation and the underlying event in hadron collisions, are shown. Finally, high $\\pt$ prompt photon measurements and studies on the production of electroweak bosons in association with jets in the final state are discussed.

  12. Simplest AB-Thermonuclear Space Propulsion and Electric Generator

    E-Print Network [OSTI]

    Alexander Bolonkin

    2007-01-19T23:59:59.000Z

    The author applies, develops and researches mini-sized Micro- AB Thermonuclear Reactors for space propulsion and space power systems. These small engines directly convert the high speed charged particles produced in the thermonuclear reactor into vehicle thrust or vehicle electricity with maximum efficiency. The simplest AB-thermonuclear propulsion offered allows spaceships to reach speeds of 20,000 50,000 km/s (1/6 of light speed) for fuel ratio 0.1 and produces a huge amount of useful electric energy. Offered propulsion system permits flight to any planet of our Solar system in short time and to the nearest non-Sun stars by E-being or intellectual robots during a single human life period. Key words: AB-propulsion, thermonuclear propulsion, space propulsion, thermonuclear power system.

  13. Jets at all scales

    E-Print Network [OSTI]

    F. Tavecchio

    2002-12-11T23:59:59.000Z

    I discuss recent developments in the field of relativistic jets in AGNs. After a brief review of our current knowledge of emission from Blazars, I discuss some consequences of the recent detection made by {\\it Chandra} of X-ray emission from extended jets. Finally I report some recent results on the problem of the connection between accretion and jets, study that in principle could shed light on the important issue of jet formation.

  14. Enabling Green Energy and Propulsion Systems via Direct Noise...

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

    Umesh Paliath, GE Global Research; Joe Insley, Argonne National Laboratory Enabling Green Energy and Propulsion Systems via Direct Noise Computation PI Name: Umesh Paliath PI...

  15. DOE Vehicle Technologies Program 2009 Merit Review Report - Propulsion...

    Broader source: Energy.gov (indexed) [DOE]

    7-1 7. Materials Technologies: Propulsion Materials Introduction Advanced materials, including metals, polymers, composites, and intermetallic compounds, can play an important role...

  16. aircraft nuclear propulsion: Topics by E-print Network

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

    engine technologies mature. Significant (more) Kirner, Rudi 2013-01-01 3 Pure Nuclear Fusion Bomb Propulsion CERN Preprints Summary: Recent progress towards the non-fission...

  17. automotive propulsion system: Topics by E-print Network

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

    analysis; automotive control system. I. INTRODUCTION In reliability Zachmann, Gabriel 49 Mini-Micro Thrusters, LOX Hydrocarbon Propulsion, and Attitude Control...

  18. automotive propulsion systems: Topics by E-print Network

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

    analysis; automotive control system. I. INTRODUCTION In reliability Zachmann, Gabriel 49 Mini-Micro Thrusters, LOX Hydrocarbon Propulsion, and Attitude Control...

  19. advanced propulsion systems: Topics by E-print Network

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

    for the tail's motion. Index terms--Fish propulsion, underwater robot, fish design. I. INTRODUCTION LTHOUGH almost all marine vehicles use propellers Papadopoulos,...

  20. aircraft propulsion reactors: Topics by E-print Network

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

    to produce adequate thrust, reduce ... Dicara, Daniel L 2006-01-01 13 Simplest AB-Thermonuclear Space Propulsion and Electric Generator CERN Preprints Summary: The author...

  1. Fusion Propulsion and Power for Future Flight

    SciTech Connect (OSTI)

    Froning, H.D. Jr.

    1996-02-01T23:59:59.000Z

    There are innovative magnetic and electric confinement fusion power and propulsion system designs with potential for: vacuum specific impulses of 1500-2000 seconds with rocket engine thrust/mass ratios of 5-10 g`s; environmentally favorable exhaust emissions if aneutronic fusion propellants can be used; a 2 to 3-fold reduction in the mass of hypersonic airliners and SSTO aerospace planes; a 10 to 20 fold reduction in Mars expedition mass and cost (if propellant from planetary atmospheres is used); and feasibility or in-feasibility of these systems could be confirmed with a modest applied research and exploratory development cost.

  2. Nuclear propulsion system options for Mars missions

    SciTech Connect (OSTI)

    Emrich, W.J. Jr.; Young, A.C. (NASA, Marshall Space Flight Center, Huntsville, AL (United States))

    1992-03-01T23:59:59.000Z

    This paper focuses on the use of a nuclear thermal rocket to accomplish a variety of space missions with emphasis on the manned Mars mission. The particle-bed-reactor type nuclear engine was chosen as the baseline engine because of its perceived versatility over other nuclear propulsion systems in conducting a wide variety of tasks. This study indicates that the particle-bed-reactor engine with its high engine thrust-to-weight ratio (about 20) and high specific impulse (about 950 to 1050 sec) offers distinct advantages over the larger and heavier NERVA-type nuclear engines.

  3. Advanced Propulsion Technology Strategy | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: The Future of1 AAcceleratedDepartment ofDepartment ofMachines Advanced||Propulsion

  4. Microquasars and Jets

    E-Print Network [OSTI]

    Sylvain Chaty

    2005-06-01T23:59:59.000Z

    I present an overview of past, present and future research on microquasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena. After remindind the analogy with quasars, I focus on one of the best microquasar representatives, probably the archetype, namely GRS 1915+105, and present accretion and ejection phenomena, showing that only a multi-wavelength approach allows a better understanding of phenomena occuring in these sources. Thereafter, I review jets at different scales: compact jets, large-scale jets, and the interactions between ejections and the surrounding medium. I finish by speaking about microblazars and ultraluminous X-ray sources.

  5. Signatures of helical jets

    E-Print Network [OSTI]

    W. Steffen

    1996-11-18T23:59:59.000Z

    Observational signatures of helical jets can be found in some X-ray binaries (XRB), planetary nebulae, Herbig-Haro objects and in jets of active galactic nuclei (AGN). For the prototypical XRB SS433 a kinematic model of precessing jets has been applied very successfully and yielded a determination of its distance which is independent of conventional methods. In galactic jets precession appears to be the predominant mechanism for the production of observed helical signatures. In extragalactic jets other mechanisms seem to be similarly frequent. As a result of their strong dependence on the direction of motion with respect to the observer, special relativistic effects can be pronounced in helical jets. These have to be taken into account in AGN-jets and the newly discovered galactic sources which show apparent superluminal motion. Since the galactic superluminal jets are located in a binary system, jet precession is very likely in these sources. In this paper I review the main structural and kinematic signatures of helical jets and briefly mention the physical mechanisms behind them. I will present kinematic simulations of relativistic jets which are helically bent or have an internal helical flow field.

  6. Jet substructure in ATLAS

    E-Print Network [OSTI]

    David W. Miller; for the ATLAS Collaboration

    2011-10-05T23:59:59.000Z

    Measurements are presented of the jet invariant mass and substructure in proton-proton collisions at sqrt{s} = 7 TeV with the ATLAS detector using an integrated luminosity of 37 pb-1. These results exercise the tools for distinguishing the signatures of new boosted massive particles in the hadronic final state. Two "fat" jet algorithms are used, along with the filtering jet grooming technique that was pioneered in ATLAS. New jet substructure observables are compared for the first time to data at the LHC. Finally, a sample of candidate boosted top quark events collected in the 2010 data is analyzed in detail for the jet substructure properties of hadronic "top-jets" in the final state. These measurements demonstrate not only our excellent understanding of QCD in a new energy regime but open the path to using complex jet substructure observables in the search for new physics.

  7. ab-ramjet space propulsion: Topics by E-print Network

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

    12 NASA Procedural Requirements NRPTA National Rocket Propulsion Testing Alliance OIG Office of Inspector General RPT Rocket Propulsion Test SLS Space Launch System...

  8. ab-thermonuclear space propulsion: Topics by E-print Network

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

    12 NASA Procedural Requirements NRPTA National Rocket Propulsion Testing Alliance OIG Office of Inspector General RPT Rocket Propulsion Test SLS Space Launch System...

  9. Advances in Magnetized Plasma Propulsion and Radiation Shielding Robert Winglee

    E-Print Network [OSTI]

    Shepherd, Simon

    Advances in Magnetized Plasma Propulsion and Radiation Shielding Robert Winglee Department of Earth Propulsion (M2P2)3,4 . In this scheme a magnetic field attached to the spacecraft is expanded-mangetosphere, that is magnetic field inflated by the injection of plasma have several applications key to the exploration

  10. A comparison of propulsion systems for potential space mission applications

    SciTech Connect (OSTI)

    Harvego, E.A.; Sulmeisters, T.K.

    1987-01-01T23:59:59.000Z

    A derivative of the NERVA nuclear rocket engine was compared with a chemical propulsion system and a nuclear electric propulsion system to assess the relative capabilities of the different propulsion system options for three potential space missions. The missions considered were (1) orbital transfer from low earth orbit (LEO) to geosynchronous earth orbit (GEO), (2) LEO to a lunar base, and (3) LEO to Mars. The results of this comparison indicate that the direct-thrust NERVA-derivative nuclear rocket engine has the best performance characteristics for the missions considered. The combined high thrust and high specific impulse achievable with a direct-thrust nuclear stage permits short operating times (transfer times) comparable to chemical propulsion systems, but with considerably less required propellant. While nuclear-electric propulsion systems are more fuel efficient than either direct-nuclear or chemical propulsion, they are not stand-alone systems, since their relatively low thrust levels require the use of high-thrust ferry or lander stages in high gravity applications such as surface-to-orbit propulsion. The extremely long transfer times and inefficient trajectories associated with electric propulsion systems were also found to be a significant drawback.

  11. Energy cost and muscular activity required for propulsion during walking

    E-Print Network [OSTI]

    Kram, Rodger

    Energy cost and muscular activity required for propulsion during walking Jinger S. Gottschall Kram. Energy cost and muscular activity required for propulsion during walk- ing. J Appl Physiol 94 there was a positive linear relationship between a horizontal impeding force and energy expen- diture. Using a wind

  12. Emissions and Performance Tradeoffs for Advanced Marine Diesel Propulsion

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    is designed that reduces smoke generation on an experimental marine Diesel engine equipped with a variable and emission generation in marine diesel propulsion. In comparison to the MIMO controller we considerEmissions and Performance Tradeoffs for Advanced Marine Diesel Propulsion Anna Stefanopoulouy

  13. Interplanetary missions with the GDM propulsion system

    SciTech Connect (OSTI)

    Kammash, T.; Emrich, W. Jr. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Marshall Space Flight Center, Huntsville, Alabama 35812 (United States)

    1998-01-15T23:59:59.000Z

    The Gasdynamic Mirror (GDM) fusion propulsion system utilizes a magnetic mirror machine in which a hot dense plasma is confined long enough to produce fusion energy while allowing a fraction of its charged particle population to escape from one end to generate thrust. The particles escaping through the opposite end have their energy converted to electric power which can be used to sustain the system in a steady state operation. With the aid of a power flow diagram the minimum demands on energy production can be established and the propulsive capability of the system can be determined by solving an appropriate set of governing equations. We apply these results to several missions within the solar system and compute the trip time by invoking a continuous burn, acceleration/deceleration type of trajectory with constant thrust and specific impulse. Ignoring gravitational effects of the planets or the sun, and neglecting the change in the Earth's position during the flight we compute the round trip time for missions from Earth to Mars, Jupiter, and Pluto using linear distances and certain payload fractions. We find that a round trip to Mars with the GDM rocket takes about 170 days while those to Jupiter and Pluto take 494 and 1566 days respectively.

  14. Ultrahigh Specific Impulse Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    Anne Charmeau; Brandon Cunningham; Samim Anghaie

    2009-02-09T23:59:59.000Z

    Research on nuclear thermal propulsion systems (NTP) have been in forefront of the space nuclear power and propulsion due to their design simplicity and their promise for providing very high thrust at reasonably high specific impulse. During NERVA-ROVER program in late 1950's till early 1970's, the United States developed and ground tested about 18 NTP systems without ever deploying them into space. The NERVA-ROVER program included development and testing of NTP systems with very high thrust (~250,000 lbf) and relatively high specific impulse (~850 s). High thrust to weight ratio in NTP systems is an indicator of high acceleration that could be achieved with these systems. The specific impulse in the lowest mass propellant, hydrogen, is a function of square root of absolute temperature in the NTP thrust chamber. Therefor optimizing design performance of NTP systems would require achieving the highest possible hydrogen temperature at reasonably high thrust to weight ratio. High hydrogen exit temperature produces high specific impulse that is a diret measure of propellant usage efficiency.

  15. Evaluation of an Impulse Gravity Generator Based Beamed Propulsion Concept

    E-Print Network [OSTI]

    Giovanni Modanese; Chris Y. Taylor

    2002-09-05T23:59:59.000Z

    This paper analyzes the suitability of a beamed propulsion concept having properties consistent with the impulse gravity generator described by Podkletnov et al. [physics/0108005]. The use of this propulsion concept for orbital maneuver, Earth-to-orbit, interplanetary, and interstellar applications based on presently available experimental results and theory is considered, and areas for future research needed to better characterize this phenomenon are discussed. A beam of radiation or particles with the properties described for the impulse gravity generator would appear to be an excellent candidate for use in beamed spacecraft propulsion. Besides the usual benefits of beamed propulsion, it would not need sails or other special spacecraft components to function, could safely provide high accelerations to delicate components, and might operate at higher efficiencies than other beamed propulsion concepts.

  16. Jet studies with STAR at RHIC: jet algorithms, jet shapes, jets in AA

    E-Print Network [OSTI]

    Jan Kapitan; for the STAR Collaboration

    2011-11-08T23:59:59.000Z

    Hard scattered partons are predicted to be well calibrated probes of the hot and dense medium produced in heavy ion collisions. Interactions of these partons with the medium w ill result in modifications of internal jet structure in Au+Au events compared to that observed in the p+p/d+Au reference. Full jet reconstruction is a promising tool to measu re these effects without the significant biases present in measurements with high-$\\pT$ hadrons. One of the most significant challenges for jet reconstruction in the heavy ion environment comes from the correct characterization of the background fluctuations. The jet mome ntum irresolution due to background fluctuations has to be understood in order to recover the correct jet spectrum. Recent progress in jet reconstruction methodology is discu ssed, as well as recent measurements from p+p, d+Au and Au+Au collisions at $\\sqrt{s_\\mathrm{NN}}=200 \\gev$.

  17. Hotspots, Jets and Environments

    E-Print Network [OSTI]

    M. J. Hardcastle

    2007-07-12T23:59:59.000Z

    I discuss the nature of `hotspots' and `jet knots' in the kpc-scale structures of powerful radio galaxies and their relationship to jet-environment interactions. I describe evidence for interaction between the jets of FRI sources and their local environments, and discuss its relationship to particle acceleration, but the main focus of the paper is the hotspots of FRIIs and on new observational evidence on the nature of the particle acceleration associated with them.

  18. Jet physics in ALICE

    E-Print Network [OSTI]

    C. Loizides

    2005-10-12T23:59:59.000Z

    This work aims at the performance of the ALICE detector for the measurement of high-energy jets at mid-pseudo-rapidity in ultra-relativistic nucleus--nucleus collisions at LHC and their potential for the characterization of the partonic matter created in these collisions. In our approach, jets at high energy with E_{T}>50 GeV are reconstructed with a cone jet finder, as typically done for jet measurements in hadronic collisions. Within the ALICE framework we study its capabilities of measuring high-energy jets and quantify obtainable rates and the quality of reconstruction, both, in proton--proton and in lead--lead collisions at LHC conditions. In particular, we address whether modification of the jet fragmentation in the charged-particle sector can be detected within the high particle-multiplicity environment of the central lead--lead collisions. We comparatively treat these topics in view of an EMCAL proposed to complete the central ALICE tracking detectors. The main activities concerning the thesis are the following: a) Determination of the potential for exclusive jet measurements in ALICE. b) Determination of jet rates that can be acquired with the ALICE setup. c) Development of a parton-energy loss model. d) Simulation and study of the energy-loss effect on jet properties.

  19. Test facilities for evaluating nuclear thermal propulsion systems

    SciTech Connect (OSTI)

    Beck, D.F.; Allen, G.C.; Shipers, L.R.; Dobranich, D.; Ottinger, C.A.; Harmon, C.D.; Fan, W.C. (Sandia National Labs., Albuquerque, NM (United States)); Todosow, M. (Brookhaven National Lab., Upton, NY (United States))

    1992-09-22T23:59:59.000Z

    Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propulsion (SNTP) program. Some preliminary results of evaluating this facility for use in testing other NTP concepts are also summarized.

  20. QCD Jets and Parton Showers

    E-Print Network [OSTI]

    Bryan R. Webber

    2010-09-29T23:59:59.000Z

    I discuss the calculation of QCD jet rates in e+e- annihilation as a testing ground for parton shower simulations and jet finding algorithms.

  1. Jet Tomography at RHIC

    E-Print Network [OSTI]

    J. C. Dunlop

    2007-07-10T23:59:59.000Z

    The status of the use of hard probes in heavy ion collisions at RHIC is reviewed. The discovery of strong jet quenching at RHIC is a major success. However, in order to make full use of this new phenomenon for full jet emission tomography of the properties of the collision zone further development is needed, both experimentally and theoretically.

  2. Molecular dynamics modeling of ionic liquids in electrospray propulsion

    E-Print Network [OSTI]

    Takahashi, Nanako

    2010-01-01T23:59:59.000Z

    Micro-propulsion has been studied for many years due to its applications in small-to-medium sized spacecraft for precise satellite attitude control. Electrospray thrusters are promising thrusters built upon the state of ...

  3. Porous material and process development for electrospray propulsion applications

    E-Print Network [OSTI]

    Arestie, Steven Mark

    2014-01-01T23:59:59.000Z

    Ion electrospray propulsion devices rely on the transportation of ionic liquid propellant to emission regions where ions are extracted at high velocities. One such method involves the use of porous substrates to passively ...

  4. Diffusion driven object propulsion in density stratified fluids

    E-Print Network [OSTI]

    Lenahan, Conor (Conor P.)

    2009-01-01T23:59:59.000Z

    An experimental study was conducted in order to verify the appropriateness of a two dimensional model of the flow creating diffusion driven object propulsion in density stratified fluids. Initial flow field experiments ...

  5. Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion

    E-Print Network [OSTI]

    . Lozano June 2010 SSL # 6-10 #12;#12;Molecular Dynamics Modeling of Ionic Liquids in Electrospray Propulsion Nanako Takahashi, Paulo C. Lozano June 2010 SSL # 6-10 This work is based on the unaltered text

  6. Electromagnetic Extraction and Annihilation of Antiprotons for Spacecraft Propulsion

    E-Print Network [OSTI]

    . Zayas, Raymond J. Sedwick May, 2008 SSL # 3-08 #12;#12;Electromagnetic Extraction and Annihilation of Antiprotons for Spacecraft Propulsion Daniel A. Zayas, Raymond J. Sedwick May, 2008 SSL # 3-08 This work

  7. Design of repeating projectile toy based on bistable spring propulsion

    E-Print Network [OSTI]

    Blanco, Matthew C. (Matthew Corwin)

    2007-01-01T23:59:59.000Z

    Recently, bistable springs have been proven as a viable propulsion method for the standard 1.75" foam balls used in Nerf® projectile toys. This technology was developed at M.I.T. by William Fienup and Barry Kudrowitz, who ...

  8. Development of a high power density motor for aircraft propulsion

    E-Print Network [OSTI]

    Dibua, Imoukhuede Tim Odion

    2007-04-25T23:59:59.000Z

    are currently powered by heavy gas turbine engines that require fueling. The development of electric motors to replace gas turbines would be a big step towards accomplishing more efficient aircraft propulsion. The primary objective of this research extends...

  9. Application of ion electrospray propulsion to lunar and interplanetary missions

    E-Print Network [OSTI]

    Whitlock, Caleb W. (Caleb Wade)

    2014-01-01T23:59:59.000Z

    High specific impulse electric propulsion systems enable ambitious lunar and interplanetary missions that return a wealth of scientific data. Many of these technologies are difficult to scale down, meaning the spacecraft ...

  10. Novel turbomachinery concepts for highly integrated airframe/propulsion systems

    E-Print Network [OSTI]

    Shah, Parthiv N

    2007-01-01T23:59:59.000Z

    Two novel turbomachinery concepts are presented as enablers to advanced flight missions requiring integrated airframe/propulsion systems. The first concept is motivated by thermal management challenges in low-to-high Mach ...

  11. Assessment of propfan propulsion systems for reduced environmental impact

    E-Print Network [OSTI]

    Peters, Andreas, Ph. D. Massachusetts Institute of Technology

    2010-01-01T23:59:59.000Z

    Current aircraft engine designs tend towards higher bypass ratio, low-speed fan designs for improved fuel burn, reduced emissions and noise. Alternative propulsion concepts include counter-rotating propfans (CRPs) which ...

  12. A doubly-fed machine for propulsion applications

    E-Print Network [OSTI]

    Tomovich, Michael S. (Michael Stephen)

    2014-01-01T23:59:59.000Z

    A doubly fed machine for propulsion applications is proposed, which, given the presence of AC and DC power sources, can be utilized in order to improve efficiency, weight, volume, and sizing of the rotor power electronics. ...

  13. Jet Propulsion Laboratory 1974-1975 Annual Report Cover The Manner 10 commemoratMl

    E-Print Network [OSTI]

    Waliser, Duane E.

    . The hydrogen injection engine project entered the vehicle system design phase. A study on alternative

  14. Portraits in Practice Iowa State University & Jet Propulsion Lab/Caltech

    E-Print Network [OSTI]

    Lutz, Robyn R.

    and Research at Siemens Corporation," led by Brian Berenbach, technical manager of the requirements engineering program, focuses on some recent projects and upcoming challenges. Siemens is one of the largest companies. Siemens Corporate Research (SCR) is part of Siemens Corporate Technology, the research arm of Siemens

  15. Thermoelectric Microdevice Fabrication Process and Evaluation at the Jet Propulsion Laboratory (JPL)

    E-Print Network [OSTI]

    panel surface area, solar flux decreases accordingly (inverse square law) and loses effective power microdevices can convert rejected or waste heat into usable electric power, at moderate (200-500K) temperatures and future directions. Introduction As a spacecraft travels further away from the sun, for a defined solar

  16. Form, function and flow in the plankton : jet propulsion and filtration by pelagic tunicates

    E-Print Network [OSTI]

    Sutherland, Kelly Rakow

    2010-01-01T23:59:59.000Z

    Trade-offs between filtration rate and swimming performance among several salp species with distinct morphologies and swimming styles were compared. Small-scale particle encounter at the salp filtering apparatus was also ...

  17. Failure Assessment Robyn Lutz, Jet Propulsion Laboratory/Caltech and Iowa State University

    E-Print Network [OSTI]

    Lutz, Robyn R.

    for failure assessment across the system lifecycle with an emphasis on the role of software. For each and characterization both of potential failure mechanisms in systems under development and of actual failure failure mechanisms in systems under development and of actual failure occurrences in operational systems

  18. Enabling Verifiable Conformance for Product Lines Jet Propulsion Laboratory/Caltech and Iowa State University

    E-Print Network [OSTI]

    Lutz, Robyn R.

    that conformance? 2. How can we enable such verification throughout the development lifecycle? This paper reports that makes or breaks the product-line practice. Verification that the software for each project satisfies its in the application engineering of NASA product lines. Lessons learned may be useful for developers of safety

  19. JET PROPULSION LABORATORY 1981 ANNUAL REPORT Qwer The tem:lln of the

    E-Print Network [OSTI]

    Waliser, Duane E.

    Imagmg Radar-A (SIR-A), flown on NASA's space shuttle Columbia In Novembelr 1981 The marbled, swtrl- mg. Thus I feel that last fall we not only passed through the nadir point in terms of es- tablishing ]PL

  20. 1997A N N U A L R E P O R T Jet Propulsion Laboratory

    E-Print Network [OSTI]

    Waliser, Duane E.

    to new positions on top of what is probably soft ice or ice-crusted water. observing NASA's Galileo spacecraft made two observations -- five months apart -- which revealed a new dark spot the size of Arizona a positive outcome: Missions are now being designed in a matter of a few weeks to a few months, in contrast

  1. JOEL AARON HUROWITZ Director's Fellow, Jet Propulsion Laboratory, California Institute of Technology (Caltech)

    E-Print Network [OSTI]

    Waliser, Duane E.

    's Workbench Training Seminar 1999-2001 Thermal Ionization Mass Spectrometer Laboratory Manager 1994-Convener: American Geophysical Union Fall Meeting 2001-2006 Emission Spectrometer Laboratory Manager 2004 NASA), Div. of Geological and Planetary Sciences, Caltech 2005-2006 Undergraduate Research Mentor, Stony

  2. Angular Scaling In Jets

    SciTech Connect (OSTI)

    Jankowiak, Martin; Larkoski, Andrew J.; /SLAC

    2012-02-17T23:59:59.000Z

    We introduce a jet shape observable defined for an ensemble of jets in terms of two-particle angular correlations and a resolution parameter R. This quantity is infrared and collinear safe and can be interpreted as a scaling exponent for the angular distribution of mass inside the jet. For small R it is close to the value 2 as a consequence of the approximately scale invariant QCD dynamics. For large R it is sensitive to non-perturbative effects. We describe the use of this correlation function for tests of QCD, for studying underlying event and pile-up effects, and for tuning Monte Carlo event generators.

  3. Gasoline Jet Fuels

    E-Print Network [OSTI]

    Kemner, Ken

    C4n= Diesel Gasoline Jet Fuels C O C5: Xylose C6 into fuels. IACT is examining these key reactions to understand the fundamental chemistry and to provide

  4. High pT Jet Physics

    E-Print Network [OSTI]

    Richard Teuscher; for the ATLAS Collaboration; for the CMS Collaboration; for the CDF Collaboration; for the D0 Collaboration

    2011-11-10T23:59:59.000Z

    This report gives a selection of recent jet results from the LHC and Tevatron, including inclusive jet production, dijets, and jets produced in association with massive vector bosons.

  5. Multiple jet interactions

    E-Print Network [OSTI]

    Hehr, Roger James

    1983-01-01T23:59:59.000Z

    MULTIPLE JET INTERACTIONS A Thesis by ROGER JAMES HEHR Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1983 Major Subject: Aerospace Engineering... MULTIPLE JET INTERACTIONS A Thesis by ROGER JAMES HEHR Approved as to style and content by: David . Norton (Chairman of Committee) raid L. orrison (Mem er) Leland A. Carlson (Member) Er est . Cross, r. (Head of Department) August 1983 ABSTRACT...

  6. A Propellantless Propulsion Experiment Design and Testing Plan

    SciTech Connect (OSTI)

    Goodwin, David P. [United States Department of Energy, Office of High Energy Physics, SC-20/Germantown Building, 1000 Independence Ave SW, Washington, D.C. 20585-1290 (United States)

    2004-02-04T23:59:59.000Z

    A propellantless propulsion experiment design and testing plan are described. The concept was initially presented during the Space Technology and Applications International Forum of 2001 and the experiment was initially presented during the Joint Propulsion Conference of 2001. New information is provided on how the experiment relates to the Human Exploration of Development of Space, the results of peer reviews, a cost estimate performed by a major U.S. aerospace company, and an alternative magnet design to reduce the cost of the experiment and potentially improve the reliability of the system. Recent improvements in high power solid state switches and superconducting magnets may have made propellantless propulsion possible. Propulsion may occur during the non-steady state ramp-up of a very rapidly pulsed, high power magnet. Propulsion would not occur after the first 100 nanoseconds of each pulse, since the magnetic field will have reached steady state. The United States Department of Energy Office of High Energy Physics provided some of the funding for the developed a no maintenance superconducting magnet that can carry 2,000 amperes per square millimeter and a switch which can provide 100 nanosecond ramp-ups at a rate of 0.4 megahertz, and at 9,000 volts and 30 amperes.

  7. Self-propulsion of V-shape micro-robot

    E-Print Network [OSTI]

    Vladimir A. Vladimirov

    2012-09-13T23:59:59.000Z

    In this paper we study the self-propulsion of a symmetric V-shape micro-robot (or V-robot) which consists of three spheres connected by two arms with an angle between them; the arms' lengths and the angle are changing periodically. Using an asymptotic procedure containing two-timing method and a distinguished limit, we obtain analytic expressions for the self-propulsion velocity and Lighthill's efficiency. The calculations show that a version of V-robot, aligned perpendicularly to the direction of self-swimming, is both the fastest one and the most efficient one. We have also shown that such $V$-robot is faster and more efficient than a linear three-sphere micro-robot. At the same time the maximal self-propulsion velocity of V-robots is significantly smaller than that of comparable microorganisms.

  8. High performance path following for marine vehicles using azimuthing podded propulsion

    E-Print Network [OSTI]

    Greytak, Matthew B. (Matthew Bardeen)

    2006-01-01T23:59:59.000Z

    Podded propulsion systems offer greater maneuvering possibilities for marine vehicles than conventional shaft and rudder systems. As the propulsion unit rotates about its vertical axis to a specified azimuth angle, the ...

  9. Naval ship propulsion and electric power systems selection for optimal fuel consumption

    E-Print Network [OSTI]

    Sarris, Emmanouil

    2011-01-01T23:59:59.000Z

    Although propulsion and electric power systems selection is an important part of naval ship design, respective decisions often have to be made without detailed ship knowledge (resistance, propulsors, etc.). Propulsion and ...

  10. Power conversion and scaling for vanishingly small satellites with electric propulsion

    E-Print Network [OSTI]

    Hansel, George J

    2014-01-01T23:59:59.000Z

    The development of ion electrospray propulsion systems (iEPS) as integrated microelectromechanical systems (i.e. MEMS) effectively miniaturizes propulsion for nanosatellites. Current iEPS thrusters consist of arrays of ion ...

  11. Bipolar Electrochemical Mechanism for the Propulsion of Catalytic Nanomotors in Hydrogen Peroxide Solutions

    E-Print Network [OSTI]

    Bipolar Electrochemical Mechanism for the Propulsion of Catalytic Nanomotors in Hydrogen Peroxide the bipolar electrochemical propulsion mechanism for bimetallic nanorods. Introduction Catalyic molecular nonbiological schemes for making micro/nanoscale ma- chines involve externally applied magnetic2 or electrical

  12. Heavy Vehicle Propulsion Materials Program: Progress and Highlights

    SciTech Connect (OSTI)

    D. Ray Johnson; Sidney Diamond

    2000-06-19T23:59:59.000Z

    The Heavy Vehicle Propulsion Materials Program was begun in 1997 to support the enabling materials needs of the DOE Office of Heavy Vehicle Technologies (OHVT). The technical agenda for the program grew out of the technology roadmap for the OHVT and includes efforts in materials for: fuel systems, exhaust aftertreatment, valve train, air handling, structural components, electrochemical propulsion, natural gas storage, and thermal management. A five-year program plan was written in early 2000, following a stakeholders workshop. The technical issues and planned and ongoing projects are discussed. Brief summaries of several technical highlights are given.

  13. Propulsion Mechanisms for Leidenfrost Solids on Ratchet Surfaces

    E-Print Network [OSTI]

    Baier, Tobias; Herbert, Stefan; Hardt, Steffen; Quere, David

    2012-01-01T23:59:59.000Z

    We propose a model for the propulsion of Leidenfrost solids on ratchets based on viscous drag due to the flow of evaporating vapor. The model assumes pressure-driven flow described by the Navier-Stokes equations and is mainly studied in lubrication approximation. A scaling expression is derived for the dependence of the propulsive force on geometric parameters of the ratchet surface and properties of the sublimating solid. We show that the model results as well as the scaling law compare favorably with experiments and are able to reproduce the experimentally observed scaling with the size of the solid.

  14. Effluent treatment options for nuclear thermal propulsion system ground tests

    SciTech Connect (OSTI)

    Shipers, L.R.; Brockmann, J.E.

    1992-10-16T23:59:59.000Z

    A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the strengths and weaknesses of different methods to handle effluent from nuclear thermal propulsion system ground tests.

  15. Handling effluent from nuclear thermal propulsion system ground tests

    SciTech Connect (OSTI)

    Shipers, L.R.; Allen, G.C.

    1992-09-09T23:59:59.000Z

    A variety of approaches for handling effluent from nuclear thermal propulsion system ground tests in an environmentally acceptable manner are discussed. The functional requirements of effluent treatment are defined and concept options are presented within the framework of these requirements. System concepts differ primarily in the choice of fission-product retention and waste handling concepts. The concept options considered range from closed cycle (venting the exhaust to a closed volume or recirculating the hydrogen in a closed loop) to open cycle (real time processing and venting of the effluent). This paper reviews the different methods to handle effluent from nuclear thermal propulsion system ground tests.

  16. Modified shielding jet model for twin-jet shielding analysis

    E-Print Network [OSTI]

    Gilbride, Jennifer Frances

    1983-01-01T23:59:59.000Z

    MODIFIED SHIELDING JET MODEL FOR TWIN-JET SHIELDING ANALYSIS A Thesis by JENNIFER FRANCES GILBRIDE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1983 Major Subject: Mechanical Engineering MODIFIED SHIELDING JET MODEL FOR TWIN-JET SHIELDING ANALYSIS A Thesis by JENNIFER FRANCES GILBRIDE Approved as to stvle and content by: 'Carl H. Gerhold (Chairman of Committee) J. Craag Dutton...

  17. A survey of processes for producing hydrogen fuel from different sources for automotive-propulsion fuel cells

    SciTech Connect (OSTI)

    Brown, L.F.

    1996-03-01T23:59:59.000Z

    Seven common fuels are compared for their utility as hydrogen sources for proton-exchange-membrane fuel cells used in automotive propulsion. Methanol, natural gas, gasoline, diesel fuel, aviation jet fuel, ethanol, and hydrogen are the fuels considered. Except for the steam reforming of methanol and using pure hydrogen, all processes for generating hydrogen from these fuels require temperatures over 1000 K at some point. With the same two exceptions, all processes require water-gas shift reactors of significant size. All processes require low-sulfur or zero-sulfur fuels, and this may add cost to some of them. Fuels produced by steam reforming contain {approximately}70-80% hydrogen, those by partial oxidation {approximately}35-45%. The lower percentages may adversely affect cell performance. Theoretical input energies do not differ markedly among the various processes for generating hydrogen from organic-chemical fuels. Pure hydrogen has severe distribution and storage problems. As a result, the steam reforming of methanol is the leading candidate process for on-board generation of hydrogen for automotive propulsion. If methanol unavailability or a high price demands an alternative process, steam reforming appears preferable to partial oxidation for this purpose.

  18. Gudrun's (NLO) list pp->WW jet

    E-Print Network [OSTI]

    Huston, Joey

    Gudrun's (NLO) list 2->3 pp->WW jet pp->VVV pp->H + 2 jets 2->4 pp->4 jets pp->tT + 2jets p->tT bB pp->V+ 3 jets pp->VV + 2 jets pp->VVV + jet pp->WW bB From technology point-of-view start with massless cases such as + 2 jets then add progressively more difficult calculations (additional scales

  19. NASA/DOE/DOD nuclear propulsion technology planning: Summary of FY 1991 interagency panel results

    SciTech Connect (OSTI)

    Clark, J.S.; Wickenheiser, T.J.; Doherty, M.P.; Marshall, A.; Bhattacharryya, S.K.; Warren, J.

    1992-01-01T23:59:59.000Z

    Interagency (NASA/DOE/DOD) technical panels worked in 1991 to evaluate critical nuclear propulsion issues, compare nuclear propulsion concepts for a manned Mars mission on a consistent basis, and to continue planning a technology development project for the Space Exploration Initiative (SEI). Panels were formed to address mission analysis, nuclear facilities, safety policy, nuclear fuels and materials, nuclear electric propulsion technology, and nuclear thermal propulsion technology. A summary of the results and recommendations of the panels is presented.

  20. Author's personal copy A versatile implicit iterative approach for fully resolved simulation of self-propulsion

    E-Print Network [OSTI]

    Hartmann, Mitra J. Z.

    . This approach uses a constraint-based formulation of the problem of self-propulsion developed by Shirgaonkar et

  1. Jet quenching in shock waves

    E-Print Network [OSTI]

    Michael Spillane; Alexander Stoffers; Ismail Zahed

    2011-10-23T23:59:59.000Z

    We study the propagation of an ultrarelativistic light quark jet inside a shock wave using the holographic principle. The maximum stopping distance and its dependency on the energy of the jet is obtained.

  2. Jet Substructure by Accident

    E-Print Network [OSTI]

    Timothy Cohen; Eder Izaguirre; Mariangela Lisanti; Hou Keong Lou

    2013-04-23T23:59:59.000Z

    We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.

  3. Jet Substructure by Accident

    E-Print Network [OSTI]

    Cohen, Timothy; Lisanti, Mariangela; Lou, Hou Keong

    2012-01-01T23:59:59.000Z

    We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.

  4. International Electric Propulsion Conference, The George Washington University, USA October 6 10, 2013

    E-Print Network [OSTI]

    Walker, Mitchell

    1 The 33rd International Electric Propulsion Conference, The George Washington University, USA Electric Propulsion Conference, The George Washington University · Washington, D.C. · USA October 6 ­ 10.t.yim@nasa.gov. #12;2 The 33rd International Electric Propulsion Conference, The George Washington University, USA

  5. Magnetic Propulsion of Intense Lithium Streams in a Tokamak Magnetic Field

    E-Print Network [OSTI]

    Zakharov, Leonid E.

    Magnetic Propulsion of Intense Lithium Streams in a Tokamak Magnetic Field Leonid E. Zakharov the theory of magnetic propulsion of liquid lithium streams and their stability in tokamaks takes into account the propulsion e#11;ect, viscosity and the drag force due to magnetic pumping

  6. Magnetic propulsion of a conducting fluid and the theory of a

    E-Print Network [OSTI]

    Zakharov, Leonid E.

    Magnetic propulsion of a conducting fluid and the theory of a controlled tokamak fusion reactor) Abstract Effect of magnetic propulsion has been discovered for conducting fluid in toroidal magnetic field. The theory has been developed for intensive, driven by magnetic propulsion, free­surface streams

  7. Velocity Fluctuations in Helical Propulsion: How Small Can a Propeller Be

    E-Print Network [OSTI]

    Rangarajan, Govindan

    applied rotating magnetic field. The method of helical propulsion becomes especially important at smallerVelocity Fluctuations in Helical Propulsion: How Small Can a Propeller Be Arijit Ghosh,,# Debadrita propulsion is at the heart of locomotion strategies utilized by various natural and artificial swimmers. We

  8. Divergence of a Propulsive Plasma Flow Expanding through a Magnetic Nozzle

    E-Print Network [OSTI]

    Choueiri, Edgar

    Divergence of a Propulsive Plasma Flow Expanding through a Magnetic Nozzle IEPC-2009-260 Presented frequency waves have renewed interest in magnetic nozzles for plasma propulsion applications in space.1 at the 31st International Electric Propulsion Conference, University of Michigan · Ann Arbor, Michigan · USA

  9. Ground test facilities for evaluating nuclear thermal propulsion engines and fuel elements

    SciTech Connect (OSTI)

    Allen, G.C.; Beck, D.F.; Harmon, C.D.; Shipers, L.R.

    1992-08-01T23:59:59.000Z

    Interagency panels evaluating nuclear thermal propulsion development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and design issues of a proposed ground test complex for evaluating nuclear thermal propulsion engines and fuel elements being developed for the Space Nuclear Thermal Propulsion (SNTP) program. 2 refs.

  10. Organic vapor jet printing system

    DOE Patents [OSTI]

    Forrest, Stephen R

    2012-10-23T23:59:59.000Z

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

  11. Inclusive Jet & DijetInclusive Jet & Dijet Production at HERAProduction at HERA

    E-Print Network [OSTI]

    Inclusive Jet & DijetInclusive Jet & Dijet Production at HERAProduction at HERA M axime.8 2-jets p 2-jets DIS Inclusive jets DIS Proton PDF S 2-jets pPhoton PDF ObservablesQCD param. #12;M. Gouzevitch (Ecole Polytechnique, France) HEP2007, Manchester, 20/07/2007 3 Jet reconstruction · Iterative

  12. Jet Production Studies at Colliders

    E-Print Network [OSTI]

    Robert Hirosky

    2013-05-02T23:59:59.000Z

    An overview of jet production, measurement techniques, and recent physics results from colliders is presented. Analyses utilizing jets and boson plus jets final states are included and implications of the data are discussed. The results presented here are a snapshot of those available at the time of the PIC 2012 conference in September 2012.

  13. Elucidating Jet Energy Loss Using Jets: Prospects from ATLAS

    E-Print Network [OSTI]

    N. Grau; for the ATLAS Collaboration

    2009-10-20T23:59:59.000Z

    Jets at the LHC are expected to provide the testing ground for studying QCD energy loss. In this contribution, we briefly outline the strategy that will be used to measure jets in ATLAS and how we will go about studying energy loss. We describe the utility of measuring the jet $R_{AA}$, the fragmentation function, and heavy flavor jets. Utilizing the collision energy provided by the LHC and the nearly hermetic and highly segmented calorimeter, ATLAS is expected to make important contributions to the understanding of parton energy loss using fully reconstructed jets.

  14. Design, Analysis, and Simulation of Rocket Propulsion System

    E-Print Network [OSTI]

    Kulhanek, Sarah Logan

    2012-08-31T23:59:59.000Z

    . The program currently provides a symbolic link in the form of a button on the output page which will open Unigraphics NX CAD program. The post-processing simulation of the rocket propulsion system is done in a computational fluid dynamics (CFD) program...

  15. Electric Propulsion for Cars: New Directions for Energy Research

    E-Print Network [OSTI]

    Firestone, Jeremy

    Electric Propulsion for Cars: New Directions for Energy Research University of Delaware Energy #12;US Gasoline Consumption Unsustainable Low Cost Cars · 250,000 first year · Millions within 5 years a Prius 220 gal/year #12;Substitute Alternative Fuels for Gasoline Electricity Natural gas Methanol ? Bio

  16. International Electric Propulsion Conference IEPC-2007-153

    E-Print Network [OSTI]

    King, Lyon B.

    30th International Electric Propulsion Conference IEPC-2007-153 1 Confinement time in an electron and magnetic fields of a Hall-effect thruster with the goal of understanding the mechanism(s) responsible for anomalous cross-field mobility. A low-density electron plasma is confined using vacuum electric and magnetic

  17. Integration of Electric Propulsion Systems with Spacecraft An Overview

    E-Print Network [OSTI]

    Walker, Mitchell

    (Gravity field and steady-state Ocean Circulation Explorer), and JAXA's Hayabusa. Around the world, various to support robotic and human solar system exploration efforts to low-power (i.e., pace of electric propulsion technologies being infused into space missions, a growing need exists

  18. Jet quenching and elliptic flow

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2007-08-29T23:59:59.000Z

    In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. Assuming that the deposited energy quickly thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP fluid. Explicit simulation of Au+Au collision with and without a quenching jet indicate that elliptic flow is greatly reduced in a jet event. The result can be used to identify the jet events in heavy ion collisions.

  19. Vortex diode jet

    DOE Patents [OSTI]

    Houck, Edward D. (Idaho Falls, ID)

    1994-01-01T23:59:59.000Z

    A fluid transfer system that combines a vortex diode with a jet ejector to transfer liquid from one tank to a second tank by a gas pressurization method having no moving mechanical parts in the fluid system. The vortex diode is a device that has a high resistance to flow in one direction and a low resistance to flow in the other.

  20. Rapidity-Dependent Jet Vetoes

    E-Print Network [OSTI]

    Shireen Gangal; Maximilian Stahlhofen; Frank J. Tackmann

    2014-12-15T23:59:59.000Z

    Jet vetoes are a prominent part of the signal selection in various analyses at the LHC. We discuss jet vetoes for which the transverse momentum of a jet is weighted by a smooth function of the jet rapidity. With a suitable choice of the rapidity-weighting function, such jet-veto variables can be factorized and resummed allowing for precise theory predictions. They thus provide a complementary way to divide phase space into exclusive jet bins. In particular, they provide a natural and theoretically clean way to implement a tight veto on central jets with the veto constraint getting looser for jets at increasingly forward rapidities. We mainly focus our discussion on the 0-jet case in color-singlet processes, using Higgs production through gluon fusion as a concrete example. For one of our jet-veto variables we compare the resummed theory prediction at NLL'+NLO with the recent differential cross section measurement by the ATLAS experiment in the $H\\to\\gamma\\gamma$ channel, finding good agreement. We also propose that these jet-veto variables can be measured and tested against theory predictions in other SM processes, such as Drell-Yan, diphoton, and weak diboson production.

  1. Flow cytometer jet monitor system

    DOE Patents [OSTI]

    Van den Engh, Ger (Seattle, WA)

    1997-01-01T23:59:59.000Z

    A direct jet monitor illuminates the jet of a flow cytometer in a monitor wavelength band which is substantially separate from the substance wavelength band. When a laser is used to cause fluorescence of the substance, it may be appropriate to use an infrared source to illuminate the jet and thus optically monitor the conditions within the jet through a CCD camera or the like. This optical monitoring may be provided to some type of controller or feedback system which automatically changes either the horizontal location of the jet, the point at which droplet separation occurs, or some other condition within the jet in order to maintain optimum conditions. The direct jet monitor may be operated simultaneously with the substance property sensing and analysis system so that continuous monitoring may be achieved without interfering with the substance data gathering and may be configured so as to allow the front of the analysis or free fall area to be unobstructed during processing.

  2. Jet hadrochemistry as a characteristics of jet quenching

    E-Print Network [OSTI]

    Sebastian Sapeta; Urs Achim Wiedemann

    2007-07-24T23:59:59.000Z

    Jets produced in nucleus-nucleus collisions at the LHC are expected to be strongly modified due to the interaction of the parton shower with the dense QCD matter. Here, we point out that jet quenching can leave signatures not only in the longitudinal and transverse jet energy and multiplicity distributions, but also in the hadrochemical composition of the jet fragments. In particular, we show that even in the absence of medium effects at or after hadronization, the medium-modification of the parton shower can result in significant changes in jet hadrochemistry. We discuss how jet hadrochemistry can be studied within the high-multiplicity environment of nucleus-nucleus collisions at the LHC.

  3. V+jets production at the CMS

    E-Print Network [OSTI]

    B. Bilin; for the CMS Collaboration

    2014-10-22T23:59:59.000Z

    Measurements of Vector Boson production in association with jets are presented, using p-p collision data at sqrt{s} = 7 TeV. The measurements presented include Z + jets azimuthal correlations, event shapes, vector boson + jets differential cross section measurements, hard double-parton scattering using W + jets events and electroweak Z + forward - backward jet production.

  4. JET Forward Programme & Opportunities for Collaboration

    E-Print Network [OSTI]

    JET Forward Programme & Opportunities for Collaboration Lorne Horton JET Exploitation Manager Contract for the Opera.on of the JET Facili.es Co-Funded by Euratom #12;L.D. Horton 2 FESAC Strategic Planning Panel 8 July 2014 - What makes JET unique! - Plans for JET exploitation

  5. Jet Energy Scale March 31, 2009

    E-Print Network [OSTI]

    Jet Energy Scale March 31, 2009 #12;Jet energy vs parton energy Eta-dependent corrections: even scale: conversion from calo measurement to underlying jet Underlying event and out-of-cone corrections region, near-100% efficiency ·Excellent momentum measurement #12;Jet clustering · Jets are formed

  6. Assessment of Space Nuclear Thermal Propulsion Facility and Capability Needs

    SciTech Connect (OSTI)

    James Werner

    2014-07-01T23:59:59.000Z

    The development of a Nuclear Thermal Propulsion (NTP) system rests heavily upon being able to fabricate and demonstrate the performance of a high temperature nuclear fuel as well as demonstrating an integrated system prior to launch. A number of studies have been performed in the past which identified the facilities needed and the capabilities available to meet the needs and requirements identified at that time. Since that time, many facilities and capabilities within the Department of Energy have been removed or decommissioned. This paper provides a brief overview of the anticipated facility needs and identifies some promising concepts to be considered which could support the development of a nuclear thermal propulsion system. Detailed trade studies will need to be performed to support the decision making process.

  7. An historical collection of papers on nuclear thermal propulsion

    SciTech Connect (OSTI)

    Not Available

    1992-01-01T23:59:59.000Z

    The present volume of historical papers on nuclear thermal propulsion (NTP) encompasses NTP technology development regarding solid-core NTP technology, advanced concepts from the early years of NTP research, and recent activities in the field. Specific issues addressed include NERVA rocket-engine technology, the development of nuclear rocket propulsion at Los Alamos, fuel-element development, reactor testing for the Rover program, and an overview of NTP concepts and research emphasizing two decades of NASA research. Also addressed are the development of the 'nuclear light bulb' closed-cycle gas core and a demonstration of a fissioning UF6 gas in an argon vortex. The recent developments reviewed include the application of NTP to NASA's Lunar Space Transportation System, the use of NTP for the Space Exploration Initiative, and the development of nuclear rocket engines in the former Soviet Union.

  8. Gravity Control Propulsion: Towards a General Relativistic Approach

    E-Print Network [OSTI]

    O. Bertolami; F. G. Pedro

    2006-10-16T23:59:59.000Z

    Evaluation of gravity control concepts should be examined with respect to currently known physical theories. In this work we study the hypothetical conversion of gravitational potential energy into kinetic energy using the formalism of general relativity. We show that the energy involved in the process greatly exceeds the Newtonian estimate, given the nature of general relativity. We conclude that the impact of any gravity manipulation for propulsion greatly depends fundamentally on its exact definition.

  9. Scoping calculations of power sources for nuclear electric propulsion

    SciTech Connect (OSTI)

    Difilippo, F.C. [Oak Ridge National Lab., TN (United States)] [Oak Ridge National Lab., TN (United States)

    1994-05-01T23:59:59.000Z

    This technical memorandum describes models and calculational procedures to fully characterize the nuclear island of power sources for nuclear electric propulsion. Two computer codes were written: one for the gas-cooled NERVA derivative reactor and the other for liquid metal-cooled fuel pin reactors. These codes are going to be interfaced by NASA with the balance of plant in order to making scoping calculations for mission analysis.

  10. Propellantless propulsion in magnetic fields by partially shielded current

    E-Print Network [OSTI]

    Bergamin, L; Pinchook, A

    2006-01-01T23:59:59.000Z

    A new device for propellantless propulsion in presence of a magnetic field is discussed. The functional principle shares some features with electrodynamic tethers. However, the tether structure is replaced by a closed wire, which is partially shielded from the magnetic field by means of a superconductor. Therefore, it does not depend on the presence of a plasma. We show that even a relatively small device can yield interesting propulsivet forces for drag compensation or for orbital transfers.

  11. Vehicle configuration options using nuclear propulsion for Mars missions

    SciTech Connect (OSTI)

    Emrich, W.J. Jr. (NASA-Marshall Space Flight Center, Huntsville, Alabama 35812 (United States))

    1993-01-20T23:59:59.000Z

    The solid core nuclear thermal rocket (NTR) provides an attractive means of providing the propulsive force needed to accomplish a wide array of space missions. With its factor of two or more advantage in Isp over chemical engines, nuclear propulsion provides the opportunity to accomplish space missions which are impractical by other means. This paper focuses on the use of a nuclear thermal rocket to accomplish a variety of space missions with emphasis on the manned Mars mission. The particle bed reactor (PBR) type nuclear engine was chosen as the baseline engine used to conduct the present study because of its perceived versatility over other nuclear propulsion systems in conducting a wide variety of tasks. This study baselines a particle bed reactor engine with an engine thrust-to-weight ratio ([similar to]11.5) and a specific impulse of [similar to]950 s. It is shown that a PBR engine of this type will offer distinct advantages over the larger and heavier NERVA type nuclear engines.

  12. Advancements in Dense Plasma Focus (DPF) for Space Propulsion

    SciTech Connect (OSTI)

    Thomas, Robert [Department of Aerospace Engineering, University of Illinois at Urbana - Champaign, Urbana, Illinois 61801 (United States); Yang Yang; Miley, G.H. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-- Champaign, Urbana, Illinois 61801 (United States); Mead, F.B. [AFRL/PRSP, 10 E. Saturn Blvd., Edwards AFB CA 93524-7680 (United States)

    2005-02-06T23:59:59.000Z

    The development of a dense plasma focus (DPF) propulsion device using p-11B is described. A propulsion system of this type is attractive because of its high thrust-to-weight ratio capabilities at high specific impulses. From a fuel standpoint, p-11B is advantageous because of the aneutronic nature of the reaction, which is favorable for the production of thrust since the charged particles can be channeled by a magnetic field. Different fusion mechanisms are investigated and their implication to the p-11B reaction is explored. Three main requirements must be satisfied to reach breakeven for DPF fusion: a high Ti/Te ratio ({approx}20), an order of magnitude higher pinch lifetime, and the reflection and absorption of at least 50% radiation. Moreover, a power re-circulation method with high efficiency must be available for the relatively low Q value of the DPF fusion reactor. A possible direct energy conversion scheme using magnetic field compression is discussed. DPF parameters are estimated for thrust levels of 1000 kN and 500 kN, and possible propulsion applications are discussed, along with developmental issues.

  13. Full fuel-cycle comparison of forklift propulsion systems.

    SciTech Connect (OSTI)

    Gaines, L. L.; Elgowainy, A.; Wang, M. Q.; Energy Systems

    2008-11-05T23:59:59.000Z

    Hydrogen has received considerable attention as an alternative to fossil fuels. The U.S. Department of Energy (DOE) investigates the technical and economic feasibility of promising new technologies, such as hydrogen fuel cells. A recent report for DOE identified three near-term markets for fuel cells: (1) Emergency power for state and local emergency response agencies, (2) Forklifts in warehousing and distribution centers, and (3) Airport ground support equipment markets. This report examines forklift propulsion systems and addresses the potential energy and environmental implications of substituting fuel-cell propulsion for existing technologies based on batteries and fossil fuels. Industry data and the Argonne Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model are used to estimate full fuel-cycle emissions and use of primary energy sources, back to the primary feedstocks for fuel production. Also considered are other environmental concerns at work locations. The benefits derived from using fuel-cell propulsion are determined by the sources of electricity and hydrogen. In particular, fuel-cell forklifts using hydrogen made from the reforming of natural gas had lower impacts than those using hydrogen from electrolysis.

  14. Jet initiation of PBX 9502

    SciTech Connect (OSTI)

    McAfee, J.M.

    1987-07-01T23:59:59.000Z

    This report details the progress of an effort to determine the quantitative aspects of the initiation of PBX 9502 (95% TATB, 5% Kel-F 800) by copper jets. The particular jet used was that produced by the LAW warhead (66-mm diameter, 42/sup 0/ angle cone, copper-lined, conical shaped charge). Fifteen experiments, in various configurations, have been fired to define the essential parameters for quantitatively measuring the jet performance and initiation of bare PBX 9502. 7 refs., 8 figs.

  15. BNL experiment with gas jet

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

    Study of Hot Electron Transport and Subsequent Ion Acceleration using Overdense Gas Jet Target and Ultrafast TW CO2 Laser System Vitaly Yakimenko, Igor Pogorelsky ATF,...

  16. Jet Physics at the Tevatron

    E-Print Network [OSTI]

    Anwar Bhatti; Don Lincoln

    2010-02-23T23:59:59.000Z

    Jets have been used to verify the theory of quantum chromodynamics (QCD), measure the structure of the proton and to search for the physics beyond the Standard Model. In this article, we review the current status of jet physics at the Tevatron, a sqrt(s) = 1.96 TeV p-pbar collider at the Fermi National Accelerator Laboratory. We report on recent measurements of the inclusive jet production cross section and the results of searches for physics beyond the Standard Model using jets. Dijet production measurements are also reported.

  17. REIMR - A Process for Utilizing Liquid Rocket Propulsion-Oriented 'Lessons Learned' to Mitigate Development Risk in Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    Ballard, Richard O. [Nuclear and Advanced Propulsion Systems Engineering Branch, NASA Marshall Space Flight Center, AL 35812 (United States)

    2006-01-20T23:59:59.000Z

    This paper is a summary overview of a study conducted at the NASA Marshall Space Flight Center (NASA-MSFC) during the initial phases of the Space Launch Initiative (SLI) program to evaluate a large number of technical problems associated with the design, development, test, evaluation and operation of several major liquid propellant rocket engine systems (i.e., SSME, Fastrac, J-2, F-1). One of the primary results of this study was the identification of the 'Fundamental Root Causes' that enabled the technical problems to manifest, and practices that can be implemented to prevent them from recurring in future propulsion system development efforts, such as that which is currently envisioned in the field of nuclear thermal propulsion (NTP). This paper will discus the Fundamental Root Causes, cite some examples of how the technical problems arose from them, and provide a discussion of how they can be mitigated or avoided in the development of an NTP system.

  18. Jet shapes with the broadening axis

    E-Print Network [OSTI]

    Larkoski, Andrew James

    Broadening is a classic jet observable that probes the transverse momentum structure of jets. Traditionally, broadening has been measured with respect to the thrust axis, which is aligned along the (hemisphere) jet momentum ...

  19. Buoyant jet behavior in confined regions

    E-Print Network [OSTI]

    Fry, David J.

    1981-01-01T23:59:59.000Z

    Previous confined jet studies have emphasized the behavior of non-buoyant jets inside ducts or near plane boundaries (Coanda effect). Buoyancy, however, is a major factor in the confined jet behavior experienced in many ...

  20. Jet Production in $pp$ Collisions: Dependence on Jet Algorithm

    E-Print Network [OSTI]

    Asmita Mukherjee; Werner Vogelsang

    2013-03-04T23:59:59.000Z

    We report on a recent calculation of single-inclusive high-$p_T$ jet production in unpolarized and longitudinally polarized $pp$ collisions at RHIC, investigating the effect of the algorithm adopted to define the jets on the numerical results for cross sections and spin asymmetries.

  1. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOE Patents [OSTI]

    Rote, D.M.; He, Jianliang; Johnson, L.R.

    1992-01-01T23:59:59.000Z

    This report discusses a propulsion and stabilization system comprising a series of figure 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the figure 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  2. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOE Patents [OSTI]

    Rote, D.M.; He, J.; Johnson, L.R.

    1994-01-04T23:59:59.000Z

    A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

  3. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOE Patents [OSTI]

    Rote, Donald M. (Lagrange, IL); He, Jianliang (Woodridge, IL); Johnson, Larry R. (Naperville, IL)

    1994-01-01T23:59:59.000Z

    A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  4. Summer Undergraduate Research Opportunities in the Electric Propulsion and Plasmadynamics Laboratory (EPPDyL)*

    E-Print Network [OSTI]

    will then be detected using a mass spectrometer. Prior experience with basic electronic instruments is desirableSummer Undergraduate Research Opportunities in the Electric Propulsion and Plasmadynamics

  5. OPENING ANGLES OF COLLAPSAR JETS

    SciTech Connect (OSTI)

    Mizuta, Akira; Ioka, Kunihito [Theory Center, Institute of Particle and Nuclear Studies, KEK, Tsukuba 305-0801 (Japan)

    2013-11-10T23:59:59.000Z

    We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by ?{sub j} ? 1/5?{sub 0} and infer the initial Lorentz factor of the jet at the central engine, ?{sub 0}, is a few for existing observations of ?{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle ?{sub j,{sub max}} ? 1/5 ? 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.

  6. Top Jets at the LHC

    E-Print Network [OSTI]

    Almeida, L.G.

    2009-01-01T23:59:59.000Z

    Top Jets at the LHC Leandro G. Almeida, Seung J. Lee, GiladSB-08-37; WIS/17/08-SEPT-DPP Top Jets at the LHC Leandro G.p T hadronically-decaying top quarks at the Large Hadron

  7. Jet Charge at the LHC

    E-Print Network [OSTI]

    David Krohn; Tongyan Lin; Matthew D. Schwartz; Wouter J. Waalewijn

    2013-06-14T23:59:59.000Z

    Knowing the charge of the parton initiating a light-quark jet could be extremely useful both for testing aspects of the Standard Model and for characterizing potential beyond-the-Standard-Model signals. We show that despite the complications of hadronization and out-of-jet radiation such as pile-up, a weighted sum of the charges of a jet's constituents can be used at the LHC to distinguish among jets with different charges. Potential applications include measuring electroweak quantum numbers of hadronically decaying resonances or supersymmetric particles, as well as Standard Model tests, such as jet charge in dijet events or in hadronically-decaying W bosons in t-tbar events. We develop a systematically improvable method to calculate moments of these charge distributions by combining multi-hadron fragmentation functions with perturbative jet functions and pertubative evolution equations. We show that the dependence on energy and jet size for the average and width of the jet charge can be calculated despite the large experimental uncertainty on fragmentation functions. These calculations can provide a validation tool for data independent of Monte-Carlo fragmentation models.

  8. Latest Jet Results from Tevatron

    E-Print Network [OSTI]

    Andrea Messina

    2006-05-16T23:59:59.000Z

    This contribution reports preliminary jet results in ppbar collisions at sqrt(s)=1.96 TeV from the CDF and D0 experiments. The jet inclusive cross section, measured using both the Midpoint and the K_T jet clustering algorithm, is compared to next-to-leading order QCD prediction in different rapidity regions. The b-jet inclusive cross section measured exploiting the long lifetime and large mass of B hadrons is presented and compared to QCD prediction. A complementary measurement, using the large branching fraction of B hadrons into muons, is also described. The measurement of two-particle momentum correlation in jets is presented and compared to predictions.

  9. Phase 1 Space Fission Propulsion Energy Source Design

    SciTech Connect (OSTI)

    Houts, Mike; Van Dyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbud, Ivana; Carter, Robert [NASA MSFC, TD40, Marshall Space Flight Center, Alabama, 35812 (United States)

    2002-07-01T23:59:59.000Z

    Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and operated. Studies conducted in fiscal year 2001 (IISTP, 2001) show that fission electric propulsion (FEP) systems with a specific mass at or below 50 kg/kWjet could enhance or enable numerous robotic outer solar system missions of interest. At the required specific mass, it is possible to develop safe, affordable systems that meet mission requirements. To help select the system design to pursue, eight evaluation criteria were identified: system integration, safety, reliability, testability, specific mass, cost, schedule, and programmatic risk. A top-level comparison of four potential concepts was performed: a Testable, Passive, Redundant Reactor (TPRR), a Testable Multi-Cell In-Core Thermionic Reactor (TMCT), a Direct Gas Cooled Reactor (DGCR), and a Pumped Liquid Metal Reactor (PLMR). Development of any of the four systems appears feasible. However, for power levels up to at least 500 kWt (enabling electric power levels of 125-175 kWe, given 25-35% power conversion efficiency) the TPRR has advantages related to several criteria and is competitive with respect to all. Hardware-based research and development has further increased confidence in the TPRR approach. Successful development and utilization of a 'Phase 1' fission electric propulsion system will enable advanced Phase 2 and Phase 3 systems capable of providing rapid, affordable access to any point in the solar system. (authors)

  10. The Use of Steady and Pulsed Detonations for Propulsion Systems

    SciTech Connect (OSTI)

    Adelman, H.G.; Menees, G.P.; Cambier, J.L.; Bowles, J.V.

    1996-02-01T23:59:59.000Z

    Objectives of the ODWE concept studies are: demonstrate the feasibility of the oblique detonation wave engine (ODWE) for hypersonic propulsion; demonstrate the existance and stability of an oblique detonation wave in hypersonic wind tunnels; develop engineering codes which predict the performance characteristics of the ODWE including specific impulse and thrust coefficients for various operating conditions; develop multi-dimensional computer codes which can model all aspects of the ODWE including fuel injection, mixing, ignition, combustion and expansion with fully detailed chemical kinetics and turbulence models; and validate the codes with experimental data use the simulations to predict the ODWE performance for conditions not easily obtained in wind tunnels.

  11. Nature-inspired microfluidic propulsion using magnetic actuation

    E-Print Network [OSTI]

    Khaderi, S N; Anderson, P D; Ioan, D; Toonder, J M J den; Onck, P R

    2009-01-01T23:59:59.000Z

    In this work we mimic the efficient propulsion mechanism of natural cilia by magnetically actuating thin films in a cyclic but non-reciprocating manner. By simultaneously solving the elasto-dynamic, magnetostatic and fluid mechanics equations, we show that the amount of fluid propelled is proportional to the area swept by the cilia. By using the intricate interplay between film magnetization and applied field we are able to generate a pronounced asymmetry and associated flow. We delineate the functional response of the system in terms of three dimensionless parameters that capture the relative contribution of elastic, inertial, viscous and magnetic forces.

  12. Recapturing NERVA-Derived Fuels for Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    Qualls, A L [ORNL] [ORNL; Hancock, Emily F [ORNL] [ORNL

    2011-01-01T23:59:59.000Z

    The Department of Energy is working with NASA to examine fuel options for Nuclear Thermal Propulsion applications. Extensive development and testing was performed on graphite-based fuels during the Nuclear Engineer Rocket Vehicle Application (NERVA) and Rover programs through the early 1970s. This paper explores the possibility of recapturing the technology and the issues associated with using it for the next generation of nuclear thermal rockets. The issues discussed include a comparison of today's testing capabilities, analysis techniques and methods, and knowledge to that of previous development programs and presents a plan to recapture the technology for a flight program.

  13. ADVANCED RADIOISOTOPE HEAT SOURCE AND PROPULSION SYSTEMS FOR PLANETARY EXPLORATION

    SciTech Connect (OSTI)

    R. C. O'Brien; S. D. Howe; J. E. Werner

    2010-09-01T23:59:59.000Z

    The exploration of planetary surfaces and atmospheres may be enhanced by increasing the range and mobility of a science platform. Fundamentally, power production and availability of resources are limiting factors that must be considered for all science and exploration missions. A novel power and propulsion system is considered and discussed with reference to a long-range Mars surface exploration mission with in-situ resource utilization. Significance to applications such as sample return missions is also considered. Key material selections for radioisotope encapsulation techniques are presented.

  14. DOE Vehicle Technologies Program 2009 Merit Review Report - Propulsion

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't Your Destiny: Theof"WaveInteractionsMaterials | Department of Energy Propulsion

  15. Propulsion Materials R&D | Clean Energy | ORNL

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible forPortsmouth/Paducah47,193.70 HgPromising MagnesiumDOE/RichlandStructure andPropulsion

  16. JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets

    E-Print Network [OSTI]

    Ellis, Steve

    JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets LPC Fermilab 5/18/09 For the next) detectors · operating at high energy and high luminosity · most of the data will be about hadrons (jets of (QCD) jets, including masses · Search for BSM physics in SINGLE jets ­ bumps in mass distributions

  17. JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets

    E-Print Network [OSTI]

    Ellis, Steve

    JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets US ATLAS Hadronic Final State Forum will be about hadrons (jets). Theory and Experiment must work together to make the most of the data. Big Picture in SINGLE jets ­ bumps in mass distributions · Consider Recombination (kT) jets natural substructure

  18. AGN jet launch scenarios Rony Keppens

    E-Print Network [OSTI]

    AGN jet launch scenarios Rony Keppens Centre for mathematical Plasma Astrophysics Department of Mathematics, KU Leuven Rony Keppens (KU Leuven) Jet launch Nov. 2013, IAC winter school 1 / 48 #12;Astrophysical Jets · astrophysical jets: ubiquitous presence of accretion disks Young Stellar Objects (YSO

  19. Latest Jet Results from the Tevatron

    E-Print Network [OSTI]

    Mikolaj Cwiok; for the CDF; D0 Collaborations

    2007-05-21T23:59:59.000Z

    Recent QCD jet production measurements in p-pbar collisions at sqrt(s)=1.96 TeV at the Tevatron Collider at Fermilab are presented. Preliminary: inclusive jet, dijet, isolated photon + jet and Z + jets measurements are compared to available perturbative QCD models.

  20. JET neutral beam power upgrade Introduction

    E-Print Network [OSTI]

    JET neutral beam power upgrade Introduction A tokamak is a complex assembly, a system of systems the challenging requirements that fusion demands. The neutral beam heating system and its upgrade for the JET systems) are the main plasma heating scheme on fusion devices such as JET and ITER. The JET neutral beam

  1. Technology survey and performance scaling for the design of high power nuclear electric power and propulsion systems

    E-Print Network [OSTI]

    White, Daniel B., Jr

    2011-01-01T23:59:59.000Z

    High power nuclear electric propulsion systems have the capability to enable many next-generation space exploration applications. To date, use of electric primary propulsion in flight systems has been limited to low-power, ...

  2. T E C H N I C A L N O T E Advantages of Natural Propulsive Systems

    E-Print Network [OSTI]

    Fish, Frank

    of this technical note is concerned with how thrust is generated by the various propulsive mechanisms exhibited biomimetic propulsive systems will be dependent on particular ap- plications, where the specifications

  3. Water cooled steam jet

    DOE Patents [OSTI]

    Wagner, Jr., Edward P. (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A water cooled steam jet for transferring fluid and preventing vapor lock, or vaporization of the fluid being transferred, has a venturi nozzle and a cooling jacket. The venturi nozzle produces a high velocity flow which creates a vacuum to draw fluid from a source of fluid. The venturi nozzle has a converging section connected to a source of steam, a diffuser section attached to an outlet and a throat portion disposed therebetween. The cooling jacket surrounds the venturi nozzle and a suction tube through which the fluid is being drawn into the venturi nozzle. Coolant flows through the cooling jacket. The cooling jacket dissipates heat generated by the venturi nozzle to prevent vapor lock.

  4. Micromachined chemical jet dispenser

    DOE Patents [OSTI]

    Swierkowski, Steve P. (Livermore, CA)

    1999-03-02T23:59:59.000Z

    A dispenser for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 .mu.m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (.about.200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments.

  5. Micromachined chemical jet dispenser

    DOE Patents [OSTI]

    Swierkowski, S.P.

    1999-03-02T23:59:59.000Z

    A dispenser is disclosed for chemical fluid samples that need to be precisely ejected in size, location, and time. The dispenser is a micro-electro-mechanical systems (MEMS) device fabricated in a bonded silicon wafer and a substrate, such as glass or silicon, using integrated circuit-like fabrication technology which is amenable to mass production. The dispensing is actuated by ultrasonic transducers that efficiently produce a pressure wave in capillaries that contain the chemicals. The 10-200 {micro}m diameter capillaries can be arranged to focus in one spot or may be arranged in a larger dense linear array (ca. 200 capillaries). The dispenser is analogous to some ink jet print heads for computer printers but the fluid is not heated, thus not damaging certain samples. Major applications are in biological sample handling and in analytical chemical procedures such as environmental sample analysis, medical lab analysis, or molecular biology chemistry experiments. 4 figs.

  6. The 32nd International Electric Propulsion Conference, Wiesbaden, Germany September 11 15, 2011

    E-Print Network [OSTI]

    The 32nd International Electric Propulsion Conference, Wiesbaden, Germany September 11 ­ 15, 2011 1 Electric Propulsion Conference, Wiesbaden · Germany September 11 ­ 15, 2011 K. Matyash1 , Max-Planck-Institut für Plasmaphysik, EURATOM Association, Greifswald, D-17491, Germany R. Schneider2 , Greifswald

  7. Definition, Expansion and Screening of Architectures for Planetary Exploration Class Nuclear Electric Propulsion and Power Systems

    E-Print Network [OSTI]

    Nuclear Electric Propulsion and Power Systems By Bryan K. Smith Submitted to the System Design, expansion and screening of Nuclear Electric Propulsion and Power concepts capable of achieving planetaryDefinition, Expansion and Screening of Architectures for Planetary Exploration Class Nuclear

  8. Design and Control of the Induction Motor Propulsion of an Electric Vehicle

    E-Print Network [OSTI]

    Brest, Université de

    Design and Control of the Induction Motor Propulsion of an Electric Vehicle B. Tabbache1,2 , A for presizing the induction motor propulsion of an Electric Vehicle (EV). Based on the EV desired performances for different induction motor-based EVs using a siding mode control technique. Index Terms--Electric Vehicle (EV

  9. The 33st International Electric Propulsion Conference, The George Washington University, USA October 6 10, 2013

    E-Print Network [OSTI]

    Walker, Mitchell

    The 33st International Electric Propulsion Conference, The George Washington University, USA, 30332, USA Abstract: Accurate measurement of ion charge flux in the plume of spacecraft electric.walker@ae.gatech.edu #12;The 33st International Electric Propulsion Conference, The George Washington University, USA

  10. The 32nd International Electric Propulsion Conference, Wiesbaden, Germany September 11 15, 2011

    E-Print Network [OSTI]

    International Electric Propulsion Conference, Wiesbaden, Germany September 11 ­ 15, 2011 2 magnetic fieldThe 32nd International Electric Propulsion Conference, Wiesbaden, Germany September 11 ­ 15, 2011 1 Effect of Magnetic Shielding on Plasma Plume of the Cylindrical Hall Thrusters IEPC-2011-175 Presented

  11. The 33st International Electric Propulsion Conference, The George Washington University, USA October 6 10, 2013

    E-Print Network [OSTI]

    King, Lyon B.

    The 33st International Electric Propulsion Conference, The George Washington University, USA with FerroTec EFH-1 in a non- uniform magnetic field IEPC-2013-319 Presented at the 33rd International Electric Propulsion Conference, The George Washington University · Washington, D.C. · USA October 6 ­ 10

  12. The 29th International Electric Propulsion Conference, Princeton University, October 31 November 4, 2005

    E-Print Network [OSTI]

    Walker, Mitchell

    The 29th International Electric Propulsion Conference, Princeton University, October 31 ­ November International Electric Propulsion Conference, Princeton University, October 31 ­ November 4, 2005 James H magnetic field transient with the vacuum facility. The thrust stand has been revamped to allow for active

  13. International Electric Propulsion Conference, Florence, Italy September 17-20, 2007

    E-Print Network [OSTI]

    Walker, Mitchell

    The 30th International Electric Propulsion Conference, Florence, Italy September 17-20, 2007 1-236 Presented at the 30th International Electric Propulsion Conference, Florence, Italy September 17-20, 2007 b = annulus outer diameter c = speed of light B = perturbed magnetic field B0 = equilibrium magnetic

  14. Principles of Rotating Plasma in Plasma Propulsion Systems N. J. Fisch

    E-Print Network [OSTI]

    Principles of Rotating Plasma in Plasma Propulsion Systems N. J. Fisch Department of Astrophysical Sciences Princeton University 33rd International Electric Propulsion Conference (IEPC2013 in crossed electric and magnetic fields. This talk reviews at a tutorial level some of the interesting

  15. International Electric Propulsion Conference, Princeton University, October 31 November 4, 2005

    E-Print Network [OSTI]

    King, Lyon B.

    The 29th International Electric Propulsion Conference, Princeton University, October 31 ­ November at the 29th International Electric Propulsion Conference, Princeton University, October 31 ­ November 4 consisting of a magnetic monopole with a constant axial E-field is used to identify fundamentals of electron

  16. International Electric Propulsion Conference, Princeton University, October 31 November 4, 2005

    E-Print Network [OSTI]

    King, Lyon B.

    The 29th International Electric Propulsion Conference, Princeton University, October 31 ­ November-effect Thruster IEPC-2005-274 Presented at the 29th International Electric Propulsion Conference, Princeton electron plasma in a pristine environment. A purely radial magnetic field is applied with a crossed

  17. An Analysis of Energy Balance in a Helicon Plasma Source for Space Propulsion

    E-Print Network [OSTI]

    An Analysis of Energy Balance in a Helicon Plasma Source for Space Propulsion by Justin Matthew;An Analysis of Energy Balance in a Helicon Plasma Source for Space Propulsion by Justin Matthew Pucci are optical radiation emission, wall losses due to poor magnetic confinement, and poor antenna-plasma coupling

  18. The Rotational Propulsion Characteristics of Scaled-up Helical Microswimmers with different heads and magnetic positioning

    E-Print Network [OSTI]

    of the cut-off frequency. The rotational propulsion characteristics of helical swimmers with a magnetic headThe Rotational Propulsion Characteristics of Scaled-up Helical Microswimmers with different heads and magnetic positioning Tiantian Xu1, Gilgueng Hwang2, Nicolas Andreff3 and St´ephane R´egnier1 Abstract

  19. Electric Motor Drive Selection Issues for HEV Propulsion Systems: A Comparative Study

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Electric Motor Drive Selection Issues for HEV Propulsion Systems: A Comparative Study M. Zeraoulia1 and on an effective comparison of the performances of the four main electric propulsion systems that are the dc motor, the induction motor, the permanent magnet synchronous motor, and the switched reluctance motor. The main

  20. A theory of jet definition

    E-Print Network [OSTI]

    Fyodor V. Tkachov

    2000-01-11T23:59:59.000Z

    A systematic framework for jet definition is developed from first principles of physical measurement, quantum field theory, and QCD. A jet definition is found which: is theoretically optimal in regard of both minimization of detector errors and inversion of hadronization; is similar to a cone algorithm with dynamically negotiated jet shapes and positions found via shape observables that generalize the thrust to any number of axes; involves no ad hoc conventions; allows a fast computer implementation [hep-ph/9912415]. The framework offers an array of options for systematic construction of quasi-optimal observables for specific applications.

  1. Radioisotope Electric Propulsion for Deep Space Sample Return

    SciTech Connect (OSTI)

    Noble, Robert J.; /SLAC

    2009-07-14T23:59:59.000Z

    The need to answer basic questions regarding the origin of the Solar System will motivate robotic sample return missions to destinations like Pluto, its satellite Charon, and objects in the Kuiper belt. To keep the mission duration short enough to be of interest, sample return from objects farther out in the Solar System requires increasingly higher return velocities. A sample return mission involves several complicated steps to reach an object and obtain a sample, but only the interplanetary return phase of the mission is addressed in this paper. Radioisotope electric propulsion is explored in this parametric study as a means to propel small, dedicated return vehicles for transferring kilogram-size samples from deep space to Earth. Return times for both Earth orbital rendezvous and faster, direct atmospheric re-entry trajectories are calculated for objects as far away as 100 AU. Chemical retro-rocket braking at Earth is compared to radioisotope electric propulsion but the limited deceleration capability of chemical rockets forces the return trajectories to be much slower.

  2. Nuclear rockets: High-performance propulsion for Mars

    SciTech Connect (OSTI)

    Watson, C.W.

    1994-05-01T23:59:59.000Z

    A new impetus to manned Mars exploration was introduced by President Bush in his Space Exploration Initiative. This has led, in turn, to a renewed interest in high-thrust nuclear thermal rocket propulsion (NTP). The purpose of this report is to give a brief tutorial introduction to NTP and provide a basic understanding of some of the technical issues in the realization of an operational NTP engine. Fundamental physical principles are outlined from which a variety of qualitative advantages of NTP over chemical propulsion systems derive, and quantitative performance comparisons are presented for illustrative Mars missions. Key technologies are described for a representative solid-core heat-exchanger class of engine, based on the extensive development work in the Rover and NERVA nuclear rocket programs (1955 to 1973). The most driving technology, fuel development, is discussed in some detail for these systems. Essential highlights are presented for the 19 full-scale reactor and engine tests performed in these programs. On the basis of these tests, the practicality of graphite-based nuclear rocket engines was established. Finally, several higher-performance advanced concepts are discussed. These have received considerable attention, but have not, as yet, developed enough credibility to receive large-scale development.

  3. Beamed Core Antimatter Propulsion: Engine Design and Optimization

    E-Print Network [OSTI]

    Ronan Keane; Wei-Ming Zhang

    2012-05-16T23:59:59.000Z

    A conceptual design for beamed core antimatter propulsion is reported, where electrically charged annihilation products directly generate thrust after being deflected and collimated by a magnetic nozzle. Simulations were carried out using the Geant4 (Geometry and tracking) software toolkit released by the CERN accelerator laboratory for Monte Carlo simulation of the interaction of particles with matter and fields. Geant permits a more sophisticated and comprehensive design and optimization of antimatter engines than the software environment for simulations reported by prior researchers. The main finding is that effective exhaust speeds Ve ~ 0.69c (where c is the speed of light) are feasible for charged pions in beamed core propulsion, a major improvement over the Ve ~ 0.33c estimate based on prior simulations. The improvement resulted from optimization of the geometry and the field configuration of the magnetic nozzle. Moreover, this improved performance is realized using a magnetic field on the order of 10 T at the location of its highest magnitude. Such a field could be produced with today's technology, whereas prior nozzle designs anticipated and required major advances in this area. The paper also briefly reviews prospects for production of the fuel needed for a beamed core engine.

  4. Strategic Control of Transverse Jet Shear Layer Instabilities J. Davitian,

    E-Print Network [OSTI]

    M'Closkey, Robert T.

    jet in crossflow or transverse jet. Jet nozzles that are flush as well as elevated with respect indicate that the jet's shear layer transitions to global instability when the jet-to-crossflow velocity THE transverse jet or jet in crossflow (JICF) is a flowfield with widespread applications in energy

  5. How to calibrate the jet energy scale?

    SciTech Connect (OSTI)

    Hatakeyama, K.; /Rockefeller U.

    2006-01-01T23:59:59.000Z

    Top quarks dominantly decay into b-quark jets and W bosons, and the W bosons often decay into jets, thus the precise determination of the jet energy scale is crucial in measurements of many top quark properties. I present the strategies used by the CDF and D0 collaborations to determine the jet energy scale. The various cross checks performed to verify the determined jet energy scale and evaluate its systematic uncertainty are also discussed.

  6. A versatile implicit iterative approach for fully resolved simulation of self-propulsion Oscar M. Curet a

    E-Print Network [OSTI]

    Curet, Oscar M.

    . This approach uses a constraint-based formulation of the problem of self-propulsion developed by Shirgaonkar et

  7. Jet Reconstruction with charged tracks only in CMS

    E-Print Network [OSTI]

    Paolo Azzurri

    2009-01-12T23:59:59.000Z

    The performance of jet finding using only charged tracks in CMS has been investigated. Different jet algorithms have been applied to QCD di-jet events, to hadronic tt multi-jet events and on Z+jets events. Results using jets made with tracks only or calorimeter towers are compared for energy response, angular resolution and jet matching to the leading partons. The jet reconstruction performance in the presence of pile-up interactions is presented for the Z+jets sample.

  8. Jet Quenching and Holographic Thermalization

    E-Print Network [OSTI]

    Elena Caceres; Arnab Kundu; Berndt Müller; Diana Vaman; Di-Lun Yang

    2012-08-31T23:59:59.000Z

    We employ the AdS/CFT correspondence to investigate the thermalization of the strongly-coupled plasma and the jet quenching of a hard probe traversing such a thermalizing medium.

  9. Jet production at hadron colliders

    E-Print Network [OSTI]

    Jouttenus, Teppo T. (Teppo Tapani)

    2012-01-01T23:59:59.000Z

    Hadronic jets feature in many final states of interest in modern collider experiments. They form a significant Standard Model background for many proposed new physics processes and also probe QCD interactions at several ...

  10. Radial flow pulse jet mixer

    DOE Patents [OSTI]

    VanOsdol, John G.

    2013-06-25T23:59:59.000Z

    The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

  11. Fragmentation inside an identified jet

    E-Print Network [OSTI]

    Procura, Massimiliano

    Using Soft?Collinear Effective Theory (SCET) we derive factorization formulae for semi?inclusive processes where a light hadron h fragments from a jet whose invariant mass is measured. Our analysis yields a novel “fragmenting ...

  12. Jet Quenching with Parton evolution

    E-Print Network [OSTI]

    Luan Cheng; Enke Wang

    2009-10-08T23:59:59.000Z

    We report the evolution effects on jet energy loss with detailed balance. The initial conditions and parton evolution based on perturbative QCD in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC are determined. The parton evolution affect the jet energy loss evidently. This will increase the energy and propagating distance dependence of the parton energy loss and will affect the shape of suppression of moderately high P_{T} hadron spectra.

  13. Stopping Cooling Flows with Jets

    E-Print Network [OSTI]

    Fabrizio Brighenti; William G. Mathews

    2006-01-24T23:59:59.000Z

    We describe 2D gasdynamical models of jets that carry mass as well as energy to the hot gas in galaxy clusters. These flows have many attractive attributes for solving the galaxy cluster cooling flow problem: Why the hot gas temperature and density profiles resemble cooling flows but show no spectral evidence of cooling to low temperatures. Using an approximate model for the cluster A1795, we show that mass-carrying jets can reduce the overall cooling rate to or below the low values implied by X-ray spectra. Biconical subrelativistic jets, described with several ad hoc parameters, are assumed to be activated when gas flows toward or cools near a central supermassive black hole. As the jets proceed out from the center they entrain more and more ambient gas. The jets lose internal pressure by expansion and are compressed by the ambient cluster gas, becoming rather difficult to observe. For a wide variety of initial jet parameters and several feedback scenarios the global cooling can be suppressed for many Gyrs while maintaining cluster temperature profiles similar to those observed. The intermittancy of the feedback generates multiple generations of X-ray cavities similar to those observed in the Perseus Cluster and elsewhere.

  14. Plasma jet ignition device

    DOE Patents [OSTI]

    McIlwain, Michael E. (Franklin, MA); Grant, Jonathan F. (Wayland, MA); Golenko, Zsolt (North Reading, MA); Wittstein, Alan D. (Fairfield, CT)

    1985-01-15T23:59:59.000Z

    An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to help plasma formation. A second improvement consists of a cavity insert containing a plurality of spaced, metal rings. The rings act as secondary spark gap electrodes reducing the voltage needed to maintain the initial arc in the cavity.

  15. Heavy Vehicle Propulsion Materials: Recent Progress and Future Plans

    SciTech Connect (OSTI)

    D. Ray Johnson; Sidney Diamond

    2001-05-14T23:59:59.000Z

    The Heavy Vehicle Propulsion Materials Program provides enabling materials technology for the U.S. DOE Office of Heavy Vehicle Technologies (OHVT). The technical agenda for the program is based on an industry assessment and the technology roadmap for the OHVT. A five-year program plan was published in 2000. Major efforts in the program are materials for diesel engine fuel systems, exhaust aftertreatment, and air handling. Additional efforts include diesel engine valve-train materials, structural components, and thermal management. Advanced materials, including high-temperature metal alloys, intermetallics, cermets, ceramics, amorphous materials, metal- and ceramic-matrix composites, and coatings, are investigated for critical engine applications. Selected technical issues and planned and ongoing projects as well as brief summaries of several technical highlights are given.

  16. Macroscopic and direct light propulsion of bulk graphene material

    E-Print Network [OSTI]

    Zhang, Tengfei; Wu, Yingpeng; Xiao, Peishuang; Yi, Ningbo; Lu, Yanhong; Ma, Yanfeng; Huang, Yi; Zhao, Kai; Yan, Xiao-Qing; Liu, Zhi-Bo; Tian, Jian-Guo; Chen, Yongsheng

    2015-01-01T23:59:59.000Z

    It has been a great challenge to achieve the direct light manipulation of matter on a bulk scale. In this work, the direct light propulsion of matter was observed on a macroscopic scale for the first time using a bulk graphene based material. The unique structure and properties of graphene and the morphology of the bulk graphene material make it capable of not only absorbing light at various wavelengths but also emitting energetic electrons efficiently enough to drive the bulk material following Newtonian mechanics. Thus, the unique photonic and electronic properties of individual graphene sheets are manifested in the response of the bulk state. These results offer an exciting opportunity to bring about bulk scale light manipulation with the potential to realize long-sought proposals in areas such as the solar sail and space transportation driven directly by sunlight.

  17. Maximum velocity of self-propulsion for an active segment

    E-Print Network [OSTI]

    Recho, Pierre

    2015-01-01T23:59:59.000Z

    The motor part of a crawling eukaryotic cell can be represented schematically as an active continuum layer. The main active processes in this layer are protrusion, originating from non-equilibrium polymerization of actin fibers, contraction, induced by myosin molecular motors and attachment due to active bonding of trans-membrane proteins to a substrate. All three active mechanisms are regulated by complex signaling pathways involving chemical and mechanical feedback loops whose microscopic functioning is still poorly understood. In this situation, it is instructive to take a reverse engineering approach and study a problem of finding the spatial organization of standard active elements inside a crawling layer ensuring an optimal cost-performance trade-off. In this paper we assume that (in the range of interest) the energetic cost of self-propulsion is velocity independent and adopt, as an optimality criterion, the maximization of the overall velocity. We then choose a prototypical setting, formulate the corr...

  18. Application of the enabler to nuclear electric propulsion

    SciTech Connect (OSTI)

    Pierce, B.L. (Westinghouse Electric Corporation Advanced Energy Systems P.O Box 158 Madison, PA 15663-0158 (US))

    1991-01-01T23:59:59.000Z

    This paper describes a power system concept that provides the electric power for a baseline electric propulsion system for a piloted mission to Mars. A 10-MWe space power system is formed by coupling an Enabler reactor with a simple non-recuperated closed Brayton cycle. The Enabler reactor is a gas-cooled reactor based on proven reactor technology developed under the NERVA/Rover programs. The selected power cycle, which uses a helium-xenon mixture at 1920 K at the turbine inlet, is diagramed and described. The specific mass of the power system over the power range from 5 to 70 MWe is given. The impact of operating life on the specific mass of a 10-MWe system is also shown.

  19. Nuclear space power and propulsion requirements and issues

    SciTech Connect (OSTI)

    Swerdling, M. [IR Associates, North Hills, CA (United States); Isenberg, L. [IR Associates, La Habra, CA (United States)

    1995-12-31T23:59:59.000Z

    The use of nuclear power in space is going through a low point. The kinds of missions that would use nuclear power are expensive and there are few new expensive missions. Both NASA and DoD are in a mode of cheaper, faster, better, which means using what is available as much as possible and only incorporating new technology to reduce mission cost. NASA is performing Mission to Planet Earth and detailed exploration missions of Mars. These NASA missions can be done with solar-battery power subsystems and there is no need for nuclear power. The NASA mission to Pluto does require nuclear radioisotope power. Ways to reduce the power subsystem cost and the power level are being investigated. NASA is studying ways to explore beyond Mars with solar-battery power because of the cost and uncertainty in the availability and launchability of nuclear space power systems. The DoD missions are all in earth orbit and can be done with solar-battery systems. The major DoD requirement at present is to reduce costs of all their space missions. One way to do this is to develop highly efficient upper stage boosters that can be integrated with lower cost Earth to low orbit stages and still place their payloads in to higher orbits. One attractive upper stage is a nuclear bimodal (propulsion and power) engine to accomplished lower booster cost to place space assets in GEO. However this is not being pursued because of DOE`s new policy not to fund nuclear space power research and development as well as the difficulty in obtaining launch approval for nuclear propulsion and power systems.

  20. MOA: Magnetic Field Oscillating Amplified Thruster and its Application for Nuclear Electric and Thermal Propulsion

    SciTech Connect (OSTI)

    Frischauf, Norbert [QASAR Technologie(s) GmbH, Johann Gottekgasse 39, A-1230, Vienna (Austria); Hettmer, Manfred; Grassauer, Andreas; Bartusch, Tobias [QASAR Technologie(s) GmbH, Johann Gottekgasse 39, A-1230, Vienna (Austria); Koudelka, Otto [Institute of Communication Networks and Satellite Communication, Graz University of Technology, Inffeldgasse 12/I, A-8010 Graz (Austria)

    2006-07-01T23:59:59.000Z

    More than 60 years after the later Nobel laureate Hannes Alfven had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto-hydrodynamic interactions in a wave like fashion, the technical implementation of Alfven waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors. The name of the concept, utilising Alfven waves to accelerate ionised matter for propulsive purposes, is MOA - Magnetic field Oscillating Amplified thruster. Alfven waves are generated by making use of two coils, one being permanently powered and serving also as magnetic nozzle, the other one being switched on and off in a cyclic way, deforming the field lines of the overall system. It is this deformation that generates Alfven waves, which are in the next step used to transport and compress the propulsive medium, in theory leading to a propulsion system with a much higher performance than any other electric propulsion system. Based on computer simulations, which were conducted to get a first estimate on the performance of the system, MOA is a highly flexible propulsion system, whose performance parameters might easily be adapted, by changing the mass flow and/or the power level. As such the system is capable to deliver a maximum specific impulse of 13116 s (12.87 mN) at a power level of 11.16 kW, using Xe as propellant, but can also be attuned to provide a thrust of 236.5 mN (2411 s) at 6.15 kW of power. While space propulsion is expected to be the prime application for MOA and is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an 'afterburner system' for Nuclear Thermal Propulsion, other terrestrial applications can be thought of as well, making the system highly suited for a common space-terrestrial application research and utilisation strategy. (authors)

  1. Soft interactions in jet quenching

    E-Print Network [OSTI]

    Carlos Hidalgo-Duque; Felipe J. Llanes-Estrada

    2014-11-05T23:59:59.000Z

    We study the collisional aspects of jet quenching in a high energy nuclear collision, especially in the final state pion gas. The jet has a large energy, and acquires momentum transverse to its axis more effectively by multiple soft collisions than by few hard scatterings (as known from analogous systems such as J/\\psi production at Hera). Such regime of large E and small momentum transfer corresponds to Regge kinematics and is characteristically dominated by the pomeron. From this insight we estimate the jet quenching parameter in the hadron medium (largely a pion gas) at the end of the collision, which is naturally small and increases with temperature in line with the gas density. The physics in the quark-gluon plasma/liquid phase is less obvious, and here we revisit a couple of simple estimates that suggest indeed that the pomeron-mediated interactions are very relevant and should be included in analysis of the jet quenching parameter. Finally, the ocasional hard collisions produce features characteristic of a L\\`evy flight in the q_perp^2 plane perpendicular to the jet axis. We suggest one- and two-particle q_perp correlations as interesting experimental probes.

  2. Jet energy scale setting with "photon+Jet" events at LHC energies. Event rates, Pt structure of jet

    E-Print Network [OSTI]

    D. V. Bandourin; V. F. Konoplianikov; N. B. Skachkov

    2000-12-15T23:59:59.000Z

    In this paper the study of "photon+Jet" events is continued, aimed at jet energy scale setting and hadron calorimeter calibration at LHC energies. The event number distribution over Pt and pseudorapidity eta in the barrel region of the photon is presented. The features of "photon+Jet" events in CMS detector |eta|<1.4 are exposed. Pt structure of the region in the eta-phi space inside and beyond jet is also shown.

  3. Gravity waves from vortex dipoles and jets

    E-Print Network [OSTI]

    Wang, Shuguang

    2009-05-15T23:59:59.000Z

    The dissertation first investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Several initially balanced and localized jets induced by vortex dipoles are examined here...

  4. Flow control via synthetic jet actuation 

    E-Print Network [OSTI]

    Miller, Adam Cole

    2005-02-17T23:59:59.000Z

    An experimental investigation was undertaken to determine the ability of Synthetic Jet Actuators to control the aerodynamic properties of a wing. The Synthetic Jet Actuator (SJA) was placed at two separate positions on ...

  5. Jet energy scale setting with "photon+Jet" events at LHC energies. Generalities, selection rules

    E-Print Network [OSTI]

    D. V. Bandourin; V. F. Konoplianikov; N. B. Skachkov

    2000-12-14T23:59:59.000Z

    "photon+Jet" events, based on the q~q-> g+photon and qg-> q+photon subprocesses, are proposed for jet energy scale setting and hadron calorimeter calibration at LHC energies. General features and selection criteria of "photon+Jet" events that would provide a good photon Pt - jet Pt balance are described. CMS detector geometry is taken as the basement.

  6. Improved e-Jet Printing -TFOT Improved e-Jet Printing

    E-Print Network [OSTI]

    Rogers, John A.

    Improved e-Jet Printing - TFOT Home Sections News Articles Forums About Us Improved e-Jet Printing at the University of Illinois have developed a technology that provides higher resolution and more versatility in e-jet printing. As opposed to conventional ink-jet printers, where heat or mechanical vibrations are used

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

    E-Print Network [OSTI]

    Budair, Mohammed Omar

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

  8. JET SCHEMES OF TORIC SURFACES ESPACES DE JETS DES SURFACES TORIQUES

    E-Print Network [OSTI]

    Favre, Charles - Institut de Mathématiques de Jussieu, Université Paris 7

    JET SCHEMES OF TORIC SURFACES ESPACES DE JETS DES SURFACES TORIQUES HUSSEIN MOURTADA Abstract. For m N, m 1, we determine the irreducible components of the m - th jet scheme of a toric surface S irr´eductibles des m-espaces des jets d'une surface torique S. Pour m assez grand, on relie le nombre

  9. JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets

    E-Print Network [OSTI]

    Ellis, Steve

    JET PRUNING: Looking for New (BSM) Physics at the LHC with Jets UC Berkeley 4/20/09 For the next) detectors · operating at high energy and high luminosity · most of the data will be about hadrons (jets Walsh & Chris Vermilion 0903.5081 #12;Outline · Brief review of jets · Searching for BSM physics

  10. ALMOST JET STRUCTURES AND FIRST JET-EXTENSIONS OF FIBRED MANIFOLDS

    E-Print Network [OSTI]

    Pasquero, Stefano

    ALMOST JET STRUCTURES AND FIRST JET-EXTENSIONS OF FIBRED MANIFOLDS Paola Morando Dipartimento di conditions for a manifold M to be diffeomorphic to the first jet­extension j1(N) of a fibred manifold N O are given in terms of almost jet structures, i.e. pairs (S, A), where S is a suitable type (2, 1) tensor

  11. Coupling between JET Pedestal ne-Te and Outer Target Plate Recycling: Consequences for JET ITER-Like-Wall Operation

    E-Print Network [OSTI]

    Coupling between JET Pedestal ne-Te and Outer Target Plate Recycling: Consequences for JET ITER-Like-Wall Operation

  12. The Remote Photogrammetric Survey and Engineering Analysis of the Divertor Structure during JET’s Remote Tile Exchange

    E-Print Network [OSTI]

    The Remote Photogrammetric Survey and Engineering Analysis of the Divertor Structure during JET’s Remote Tile Exchange

  13. Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part I: The JET In-vessel Cryopump

    E-Print Network [OSTI]

    Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part I: The JET In-vessel Cryopump

  14. Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part II: The JET LHCD Cryopump

    E-Print Network [OSTI]

    Theoretical and Experimental Simulation of Accident Scenarios of the JET Cryogenic Components Part II: The JET LHCD Cryopump

  15. Jets in relativistic heavy ion collisions

    SciTech Connect (OSTI)

    Wang, Xin-Nian; Gyulassy, M.

    1990-09-01T23:59:59.000Z

    Several aspects of hard and semihard QCD jets in relativistic heavy ion collisions are discussed, including multiproduction of minijets and the interaction of a jet with dense nuclear matter. The reduction of jet quenching effect in deconfined phase of nuclear matter is speculated to provide a signature of the formation of quark gluon plasma. HIJING Monte Carlo program which can simulate events of jets production and quenching in heavy ion collisions is briefly described. 35 refs., 13 figs.

  16. Jet physics and strong coupling at HERA

    E-Print Network [OSTI]

    Maxime Gouzevitch

    2009-06-05T23:59:59.000Z

    Jet production in electron-proton scattering at HERA provides an important testing ground for Quantum Chromodynamics (QCD). The inclusive jet and multi-jet cross sections recently measured by H1 and ZEUS collaborations allow a precise determination of the strong coupling and test of its running. Additionally, a measurement of the angular correlations in the 3-jet events gives a handle on the fundamental gauge structure of the QCD.

  17. Jet physics at HERA, Tevatron and LHC

    E-Print Network [OSTI]

    C. Royon

    2008-11-10T23:59:59.000Z

    In this short report, we discuss the Jet Physics results and perspectives at HERA, Tevatron and LHC.

  18. Inclusive jet production at the Tevatron

    SciTech Connect (OSTI)

    Norniella, Olga; /Barcelona, IFAE

    2006-08-01T23:59:59.000Z

    Preliminary results on inclusive jet production in proton-antiproton collisions at {radical}s = 1.96 TeV based on 1 fb{sup -1} of CDF Run II data are presented. Measurements are preformed using different jet algorithms in a wide range of jet transverse momentum and jet rapidity. The measured cross sections are compared to next-to-leading order perturbative QCD calculations

  19. Advanced thermally stable jet fuels

    SciTech Connect (OSTI)

    Schobert, H.H.

    1999-01-31T23:59:59.000Z

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume (Sections 1 through 5).

  20. Jet quenching and $?$-jet correlation in high-energy heavy-ion collisions

    E-Print Network [OSTI]

    Xin-Nian Wang; Yan Zhu

    2014-07-16T23:59:59.000Z

    Medium modification of $\\gamma$-tagged jets in high-energy heavy-ion collisions is investigated within a linearized Boltzmann transport model which includes both elastic parton scattering and induced gluon emission. In Pb+Pb collisions at $\\sqrt{s}=2.76$ TeV, a $\\gamma$-tagged jet is seen to lose 15\\% of its energy at 0-10\\% central collisions. Simulations also point to a sizable azimuthal angle broadening of $\\gamma$-tagged jets at the tail of a distribution which should be measurable when experimental errors are significantly reduced. An enhancement at large $z_\\text{jet}=p_L/E_{\\text{jet}}$ in jet fragmentation function at the Large Hadron Collider (LHC) can be attributed to the dominance of leading particles in the reconstructed jet. A $\\gamma-$tagged jet fragmentation function is shown to be more sensitive to jet quenching, therefore a better probe of the jet transport parameter.

  1. Submarine propulsion shaft life : probabilistic prediction and extension through prevention of water ingress

    E-Print Network [OSTI]

    Jonart, Douglas E. (Douglas Edward)

    2014-01-01T23:59:59.000Z

    Submarine propulsion shafts have demonstrated acceptable reliability performance when inspected and refurbished at least every 6 years. Designers wish to extend the inspection interval to 12 years without sacrificing ...

  2. Analysis of Advanced Actinide-Fueled Energy Systems for Deep Space Propulsion Applications 

    E-Print Network [OSTI]

    Guy, Troy Lamar

    2011-02-22T23:59:59.000Z

    The present study is focused on evaluating higher actinides beyond uranium that are capable of supporting power and propulsion requirements in robotic deep space and interstellar exploration. The central technology in this ...

  3. A fully microfabricated two-dimensional electrospray array with applications to space propulsion

    E-Print Network [OSTI]

    Gassend, Blaise L. P. (Blaise Laurent Patrick), 1978-

    2007-01-01T23:59:59.000Z

    This thesis presents the design, fabrication and testing of a fully-integrated planar electrospray thruster array, which could lead to more efficient and precise thrusters for space propulsion applications. The same ...

  4. Innovative nuclear thermal propulsion technology evaluation: Results of the NASA/DOE Task Team study

    SciTech Connect (OSTI)

    Howe, S. (Los Alamos National Lab., NM (United States)); Borowski, S. (National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center); Motloch, C. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Helms, I. (Nuclear Utility Services, Damascus, MD (United States)); Diaz, N.; Anghaie, S. (Florida Univ., Gainesville, FL (United States)); Latham, T. (United

    1991-01-01T23:59:59.000Z

    In response to findings from two NASA/DOE nuclear propulsion workshops held in the summer of 1990, six task teams were formed to continue evaluation of various nuclear propulsion concepts. The Task Team on Nuclear Thermal Propulsion (NTP) created the Innovative Concepts Subpanel to evaluate thermal propulsion concepts which did not utilize solid fuel. The Subpanel endeavored to evaluate each of the concepts on a level technological playing field,'' and to identify critical technologies, issues, and early proof-of-concept experiments. The concepts included the liquid core fission, the gas core fission, the fission foil reactors, explosively driven systems, fusion, and antimatter. The results of the studies by the panel will be provided. 13 refs., 6 figs., 2 tabs.

  5. The design and feasibility of a 10 mN chemical space propulsion thruster

    E-Print Network [OSTI]

    Bruccoleri, Alexander Robert

    2009-01-01T23:59:59.000Z

    This thesis discusses the design of a ten milli Newton chemical propulsion system for providing approximately 200 m/s delta velocity to a five kg satellite. The nozzle is the focus of the experimental work, which involves ...

  6. An impulse framework for hydrodynamic force analysis : fish propulsion, water entry of spheres, and marine propellers

    E-Print Network [OSTI]

    Epps, Brenden P

    2010-01-01T23:59:59.000Z

    This thesis presents an impulse framework for analyzing the hydrodynamic forces on bodies in flow. This general theoretical framework is widely applicable, and it is used to address the hydrodynamics of fish propulsion, ...

  7. Probing nuclear matter with jet conversions

    E-Print Network [OSTI]

    Liu, W.; Fries, Rainer J.

    2008-01-01T23:59:59.000Z

    We discuss the flavor of leading jet partons as a valuable probe of nuclear matter. We point out that the coupling of jets to nuclear matter naturally leads to an alteration of jet chemistry even at high transverse momentum PT. In particular...

  8. ALTERNATIVE JET FUEL SCENARIO ANALYSIS Final Report

    E-Print Network [OSTI]

    1 ALTERNATIVE JET FUEL SCENARIO ANALYSIS REPORT Final Report U.S. Department of Transportation Alternative jet fuel scenario analysis report 5. FUNDING NUMBERS 6. AUTHOR(S) Kristin Lewis, Shuchi Mitra production of alternative aviation (jet) fuels in North America (United States, Canada, and Mexico

  9. Monte Carlo Tools for Jet Quenching

    E-Print Network [OSTI]

    Korinna Zapp

    2011-09-07T23:59:59.000Z

    A thorough understanding of jet quenching on the basis of multi-particle final states and jet observables requires new theoretical tools. This talk summarises the status and propects of the theoretical description of jet quenching in terms of Monte Carlo generators.

  10. Jet Studies at CMS and ATLAS

    E-Print Network [OSTI]

    Konstantinos Kousouris

    2009-06-11T23:59:59.000Z

    The jet reconstruction and jet energy calibration strategies adopted by the CMS and ATLAS experiments are presented. Jet measurements that can be done with early data to confront QCD at the highest transverse momentum scale and search for new physics are described.

  11. Thermal-hydraulics Analysis of a Radioisotope-powered Mars Hopper Propulsion System

    SciTech Connect (OSTI)

    Robert C. O'Brien; Andrew C. Klein; William T. Taitano; Justice Gibson; Brian Myers; Steven D. Howe

    2011-02-01T23:59:59.000Z

    Thermal-hydraulics analyses results produced using a combined suite of computational design and analysis codes are presented for the preliminary design of a concept Radioisotope Thermal Rocket (RTR) propulsion system. Modeling of the transient heating and steady state temperatures of the system is presented. Simulation results for propellant blow down during impulsive operation are also presented. The results from this study validate the feasibility of a practical thermally capacitive RTR propulsion system.

  12. Heavy vehicle hybrid propulsion systems R and D program plan, FY 2000-2005

    SciTech Connect (OSTI)

    None

    2000-07-01T23:59:59.000Z

    This report contains the program plan and background information for the Heavy Vehicle Hybrid Propulsion R and D Program sponsored by the Department of Energy's Office of Heavy Vehicle Technologies. The program is a collaboration between industry and government established for the development of advanced hybrid-electric propulsion technology for urban cycle trucks and buses. It targets specific applications to enhance potential market success. Potential end-users are also involved.

  13. Magnetic Propulsion of Intense Lithium Streams in a Tokamak Magnetic Field

    SciTech Connect (OSTI)

    Leonid E. Zakharov

    2002-03-13T23:59:59.000Z

    The paper gives the theory of magnetic propulsion of liquid lithium streams and their stability in tokamaks. In the approximation of a thin flowing layer the MHD equations are reduced to one integro-differential equation which takes into account the propulsion effect, viscosity and the drag force due to magnetic pumping and other interactions with the magnetic field. A criterion is obtained for the stabilization of the ''sausage'' instability of the streams by centrifugal force.

  14. JOURNAL OF PROPULSION AND POWER Vol. 22, No. 2, MarchApril 2006

    E-Print Network [OSTI]

    Thole, Karen A.

    to predict. The interaction of jets-in-crossflow, which is representative of film cooling, results in a shear is highly dependent on the jet-to-crossflow mass and momentum flux ratios. Film-cooling performance

  15. RSMASS-D nuclear thermal propulsion and bimodal system mass models

    SciTech Connect (OSTI)

    King, D.B. [DSWA/FC, Thermionic Evaluation Facility 801 University Blvd. SE Albuquerque, New Mexico (United States); Marshall, A.C. [DSWA/FC, Thermionic Evaluation Facility 801 University Blvd. SE Albuquerque, New Mexico (United States)

    1997-01-01T23:59:59.000Z

    Two relatively simple models have been developed to estimate reactor, radiation shield, and balance of system masses for a particle bed reactor (PBR) nuclear thermal propulsion concept and a cermet-core power and propulsion (bimodal) concept. The approach was based on the methodology developed for the RSMASS-D models. The RSMASS-D approach for the reactor and shield sub-systems uses a combination of simple equations derived from reactor physics and other fundamental considerations along with tabulations of data from more detailed neutron and gamma transport theory computations. Relatively simple models are used to estimate the masses of other subsystem components of the nuclear propulsion and bimodal systems. Other subsystem components include instrumentation and control (I&C), boom, safety systems, radiator, thermoelectrics, heat pipes, and nozzle. The user of these models can vary basic design parameters within an allowed range to achieve a parameter choice which yields a minimum mass for the operational conditions of interest. Estimated system masses are presented for a range of reactor power levels for propulsion for the PBR propulsion concept and for both electrical power and propulsion for the cermet-core bimodal concept. The estimated reactor system masses agree with mass predictions from detailed calculations with xx percent for both models. {copyright} {ital 1997 American Institute of Physics.}

  16. RSMASS-D nuclear thermal propulsion and bimodal system mass models

    SciTech Connect (OSTI)

    King, Donald B.; Marshall, Albert C. [DSWA/FC, Thermionic Evaluation Facility 801 University Blvd. SE Albuquerque, New Mexico (United States); DSWA/FC, Thermionic Evaluation Facility 801 University Blvd. SE Albuquerque, New Mexico (United States)

    1997-01-10T23:59:59.000Z

    Two relatively simple models have been developed to estimate reactor, radiation shield, and balance of system masses for a particle bed reactor (PBR) nuclear thermal propulsion concept and a cermet-core power and propulsion (bimodal) concept. The approach was based on the methodology developed for the RSMASS-D models. The RSMASS-D approach for the reactor and shield sub-systems uses a combination of simple equations derived from reactor physics and other fundamental considerations along with tabulations of data from more detailed neutron and gamma transport theory computations. Relatively simple models are used to estimate the masses of other subsystem components of the nuclear propulsion and bimodal systems. Other subsystem components include instrumentation and control (I and C), boom, safety systems, radiator, thermoelectrics, heat pipes, and nozzle. The user of these models can vary basic design parameters within an allowed range to achieve a parameter choice which yields a minimum mass for the operational conditions of interest. Estimated system masses are presented for a range of reactor power levels for propulsion for the PBR propulsion concept and for both electrical power and propulsion for the cermet-core bimodal concept. The estimated reactor system masses agree with mass predictions from detailed calculations with xx percent for both models.

  17. Full Jet Reconstruction in Heavy Ion Collisions

    E-Print Network [OSTI]

    Sevil Salur

    2009-09-16T23:59:59.000Z

    Full jet reconstruction has traditionally been thought to be difficult in heavy ion events due to large multiplicity backgrounds. The search for new physics in high luminosity p+p collisions at the LHC similarly requires the precise measurement of jets over large backgrounds caused by pile up; this has motivated the development of a new generation of jet reconstruction algorithms which are also applicable in the heavy ion environment. We review the latest results on jet-medium interactions as seen in A+A collisions at RHIC, focusing on the new techniques for full jet reconstruction.

  18. On jet structure in heavy ion collisions

    E-Print Network [OSTI]

    I. P. Lokhtin; A. A. Alkin; A. M. Snigirev

    2015-04-19T23:59:59.000Z

    The LHC data on jet fragmentation function and jet shapes in PbPb collisions at center-of-mass energy 2.76 TeV per nucleon pair are analyzed and interpreted in the frameworks of PYQUEN jet quenching model. A specific modification of longitudinal and radial jet profiles in most central PbPb collisions as compared with pp data is close to that obtained with PYQUEN simulations taking into account wide-angle radiative and collisional partonic energy loss. The contribution of radiative and collisional loss to the medium-modified intra-jet structure is estimated.

  19. Jet energy scale setting with "photon+Jet" events at LHC energies. Selection of events with a clean "photon+Jet" topology and photon Pt - jet Pt disbalance

    E-Print Network [OSTI]

    D. V. Bandourin; V. F. Konoplyanikov; N. B. Skachkov

    2001-04-27T23:59:59.000Z

    It is shown in the paper that Pt activity limitation (modulus of the vector sum) of all particle beyond "photon+Jet" system Pt^out leads to the noticeable photon Pt - jet Pt disbalance decreasing. On a simultaneous restriction of the cluster Pt and Pt^out from above it is possible to reach an acceptable balance between photon Pt - jet Pt with a sufficient number of the photon Pt - jet Pt events for the jet energy scale setting and hadron calorimeter calibratiom of the CMS detector at LHC.

  20. Laser Created Relativistic Positron Jets

    SciTech Connect (OSTI)

    Chen, H; Wilks, S C; Meyerhofer, D D; Bonlie, J; Chen, C D; Chen, S N; Courtois, C; Elberson, L; Gregori, G; Kruer, W; Landoas, O; Mithen, J; Murphy, C; Nilson, P; Price, D; Scheider, M; Shepherd, R; Stoeckl, C; Tabak, M; Tommasini, R; Beiersdorder, P

    2009-10-08T23:59:59.000Z

    Electron-positron jets with MeV temperature are thought to be present in a wide variety of astrophysical phenomena such as active galaxies, quasars, gamma ray bursts and black holes. They have now been created in the laboratory in a controlled fashion by irradiating a gold target with an intense picosecond duration laser pulse. About 10{sup 11} MeV positrons are emitted from the rear surface of the target in a 15 to 22-degree cone for a duration comparable to the laser pulse. These positron jets are quasi-monoenergetic (E/{delta}E {approx} 5) with peak energies controllable from 3-19 MeV. They have temperatures from 1-4 MeV in the beam frame in both the longitudinal and transverse directions. Positron production has been studied extensively in recent decades at low energies (sub-MeV) in areas related to surface science, positron emission tomography, basic antimatter science such as antihydrogen experiments, Bose-Einstein condensed positronium, and basic plasma physics. However, the experimental tools to produce very high temperature positrons and high-flux positron jets needed to simulate astrophysical positron conditions have so far been absent. The MeV temperature jets of positrons and electrons produced in our experiments offer a first step to evaluate the physics models used to explain some of the most energetic phenomena in the universe.

  1. The Disc-Jet Connection

    E-Print Network [OSTI]

    Ralph E. Pudritz; Robi Banerjee

    2005-07-11T23:59:59.000Z

    A large body of theoretical and computational work shows that jets - modelled as magnetized disk winds - exert an external torque on their underlying disks that can efficiently remove angular momentum and act as major drivers of disk accretion. These predictions have recently been confirmed in direct HST measurements of the jet rotation and angular momentum transport in low mass protostellar systems. We review the theory of disc winds and show that their physics is universal and scales to jets from both low and high mass star forming regions. This explains the observed properties of outflows in massive star forming regions, before the central massive star generates an ultracompact HII region. We also discuss the recent numerical studies on the formation of massive accretion disks and outflows through gravitational collapse, including our own work on 3D Adaptive Mesh simulations (using the FLASH code) of the hydromagnetic collapse of an initial rotating, and cooling Bonner-Ebert sphere. Magnetized collapse gives rise to outflows. Our own simulations show that both a jet-like disk wind on sub AU scales, and a larger scale molecular outflow occur (Banerjee and Pudritz 2005).

  2. Shear Layer Instabilities and Mixing in Variable Density Transverse Jet Flows

    E-Print Network [OSTI]

    Getsinger, Daniel

    2012-01-01T23:59:59.000Z

    of the Jet in Crossflow . . . . . . . . . . . . . . .The Variable Density Jet in Crossflow . . . . . . . . .The Single-Phase Jet in Crossflow . . . . . . .

  3. A tandem mirror hybrid plume plasma propulsion facility

    SciTech Connect (OSTI)

    Chang-Diaz, F.R.; Yang, T.F.; Krueger, W.A.; Peng, S.; Urbahn, J.; Yao, X.; Griffin, D.

    1988-01-01T23:59:59.000Z

    A concept in electrodeless plasma propulsion, which is also capable of delivering a variable Isp, is presented. The concept involves a three-stage system of plasma injection, heating, and subsequent ejection through a magnetic nozzle. The nozzle produces the hybrid plume by the coaxial injection of hypersonic neutral gas. The gas layer, thus formed, protects the material walls from the hot plasma and, through increased collisions, helps detach it from the diverging magnetic field. The physics of this concept is evaluated numerically through full spatial and temporal simulations; these explore the operating characteristics of such a device over a wide region of parameter space. An experimental facility to study the plasma dynamics in the hybrid plume was built. The device consists of a tandem mirror operating in an asymmetric mode. A later upgrade of this system will incorporate a cold plasma injector at one end of the machine. Initial experiments involve the full characterization of the operating envelope, as well as extensive measurements of plasma properties at the exhaust. The results of the numerical simulations are described.

  4. Assessment of a hot hydrogen nuclear propulsion fuel test facility

    SciTech Connect (OSTI)

    Watanabe, H.H.; Howe, S.D.; Wantuck, P.J.

    1991-01-01T23:59:59.000Z

    Subsequent to the announcement of the Space Exploration Initiative (SEI), several studies and review groups have identified nuclear thermal propulsion as a high priority technology for development. To achieve the goals of SEI to place man on Mars, a nuclear rocket will operate at near 2700K and in a hydrogen environment at near 60 atmospheres. Under these conditions, the operational lifetime of the rocket will be limited by the corrosion rate at the hydrogen/fuel interface. Consequently, the Los Alamos National Laboratory has been evaluating requirements and design issues for a test facility. The facility will be able to directly heat fuel samples by electrical resistance, microwave deposition, or radio frequency induction heating to temperatures near 3000K. Hydrogen gas at variable pressure and temperatures will flow through the samples. The thermal gradients, power density, and operating times envisioned for nuclear rockets will be duplicated as close as reasonable. The post-sample flow stream will then be scrubbed and cooled before reprocessing. The baseline design and timetable for the facility will be discussed. 7 refs.

  5. Generation of the magnetic field in jets

    E-Print Network [OSTI]

    V. Urpin

    2006-05-22T23:59:59.000Z

    We consider dynamo action under the combined influence of turbulence and large-scale shear in sheared jets. Shear can stretch turbulent magnetic field lines in such a way that even turbulent motions showing mirror symmetry become suitable for generation of a large-scale magnetic field. We derive the integral induction equation governing the behaviour of the mean field in jets. The main result is that sheared jets may generate a large-scale magnetic field if shear is sufficiently strong. The generated mean field is mainly concentrated in a magnetic sheath surrounding the central region of a jet, and it exhibits sign reversals in the direction of the jet axis. Typically, the magnetic field in a sheath is dominated by the component along the jet that can reach equipartition with the kinetic energy of particles, The field in the central region of jets has a more disordered structure.

  6. Calculating Jet $v_n$ and the Event Plane in the Presence of a Jet

    E-Print Network [OSTI]

    Alice Ohlson

    2013-03-26T23:59:59.000Z

    Advances in measurements of jets and collective phenomena in ultrarelativistic heavy ion collisions have led to further understanding of the properties of the medium created in such collisions. Measurements of the correlations between the axes of reconstructed jets and the reaction plane or second-order participant plane of the bulk medium (defined as jet $v_2$), as well as the higher-order participant planes (jet $v_n$), provide information on medium-induced parton energy loss. Additionally, knowledge of jet $v_n$ as well as the ability to reconstruct the event plane in the presence of a jet are necessary in analyses of jet-triggered particle correlations, which are used to study medium-induced jet shape modification. However, the presence of a jet can bias the event plane calculation, leading to an overestimation of jet $v_2$. This paper proposes a method for calculating jet $v_2$ (and by extension, the higher jet $v_n$ harmonics) and the event plane in an unbiased way, using knowledge of the azimuthal angle of the jet axis from full jet reconstruction.

  7. A New Capability for Nuclear Thermal Propulsion Design

    SciTech Connect (OSTI)

    Amiri, Benjamin W. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Nuclear and Radiological Engineering Department, University of Florida, Gainesville, FL 32611 (United States); Kapernick, Richard J. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sims, Bryan T. [Nuclear Systems Design Group, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Simpson, Steven P. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2007-01-30T23:59:59.000Z

    This paper describes a new capability for Nuclear Thermal Propulsion (NTP) design that has been developed, and presents the results of some analyses performed with this design tool. The purpose of the tool is to design to specified mission and material limits, while maximizing system thrust to weight. The head end of the design tool utilizes the ROCket Engine Transient Simulation (ROCETS) code to generate a system design and system design requirements as inputs to the core analysis. ROCETS is a modular system level code which has been used extensively in the liquid rocket engine industry for many years. The core design tool performs high-fidelity reactor core nuclear and thermal-hydraulic design analysis. At the heart of this process are two codes TMSS-NTP and NTPgen, which together greatly automate the analysis, providing the capability to rapidly produce designs that meet all specified requirements while minimizing mass. A PERL based command script, called CORE DESIGNER controls the execution of these two codes, and checks for convergence throughout the process. TMSS-NTP is executed first, to produce a suite of core designs that meet the specified reactor core mechanical, thermal-hydraulic and structural requirements. The suite of designs consists of a set of core layouts and, for each core layout specific designs that span a range of core fuel volumes. NTPgen generates MCNPX models for each of the core designs from TMSS-NTP. Iterative analyses are performed in NTPgen until a reactor design (fuel volume) is identified for each core layout that meets cold and hot operation reactivity requirements and that is zoned to meet a radial core power distribution requirement.

  8. Jet Veto Clustering Logarithms Beyond Leading Order

    E-Print Network [OSTI]

    Simone Alioli; Jonathan R. Walsh

    2014-11-23T23:59:59.000Z

    Many experimental analyses separate events into exclusive jet bins, using a jet algorithm to cluster the final state and then veto on jets. Jet clustering induces logarithmic dependence on the jet radius R in the cross section for exclusive jet bins, a dependence that is poorly controlled due to the non-global nature of the clustering. At jet radii of experimental interest, the leading order (LO) clustering effects are numerically significant, but the higher order effects are currently unknown. We rectify this situation by calculating the most important part of the next-to-leading order (NLO) clustering logarithms of R for any 0-jet process, which enter as $O(\\alpha_s^3)$ corrections to the cross section. The calculation blends subtraction methods for NLO calculations with factorization properties of QCD and soft-collinear effective theory (SCET). We compare the size of the known LO and new NLO clustering logarithms and find that the impact of the NLO terms on the 0-jet cross section in Higgs production is small. This brings clustering effects under better control and may be used to improve uncertainty estimates on cross sections with a jet veto.

  9. Jet-hadron correlations in STAR

    E-Print Network [OSTI]

    Alice Ohlson; for the STAR Collaboration

    2011-06-29T23:59:59.000Z

    In recent years, the study of dihadron correlations has been one of the primary methods used to investigate the propagation and modification of hard-scattered partons through the QGP. Due to recent advances in jet-finding algorithms, it is now possible to use reconstructed jets in these correlation studies, extending the kinematic reach compared to dihadron analyses. The results of the jet-hadron correlation analysis indicate a broadening and softening of jets that interact with the medium. Jet-hadron correlations can also be used to assess the systematics of other jet-like correlation analyses, such as 2+1 correlations. It is shown that the jets selected in 2+1 correlations are relatively unmodified. Future work will include an analysis of jet-hadron correlations with respect to the event plane to measure the pathlength dependence of parton energy loss. The first steps in this analysis indicate that complications arise when calculating the event plane in the presence of a jet as well as in calculating jet v2. The data analyzed were collected by the STAR detector in sqrt(s_NN) = 200 GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC).

  10. VELOCITY FIELD OF A ROUND TURBULENT TRANSVERSE JET Suman Muppidi

    E-Print Network [OSTI]

    Mahesh, Krishnan

    - bulent jet in a laminar crossflow. The velocity ratio is 5.7 and the Reynolds number is 5000. Mean Jets in crossflow, also called `transverse jets' are defined as the flow field where a jet of fluid enters and interacts with a crossflowing fluid. Examples of jets in crossflow are fuel injectors

  11. Fluid jet electric discharge source

    DOE Patents [OSTI]

    Bender, Howard A. (Ripon, CA)

    2006-04-25T23:59:59.000Z

    A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.

  12. Turbulent fluid jet excavation in cohesive soil : with particular application to jet grouting

    E-Print Network [OSTI]

    Ho, Chu Eu

    2005-01-01T23:59:59.000Z

    This thesis reviews the jet grouting methodology, and the current state of practice and research. Current methods of prediction of jet grout diameters are highly empirical and site specific, and do not take into account ...

  13. Jet impact on a soap film

    E-Print Network [OSTI]

    Geoffroy Kirstetter; Christophe Raufaste; Franck Celestini

    2012-08-17T23:59:59.000Z

    We experimentally investigate the impact of a liquid jet on a soap film. We observe that the jet never breaks the film and that two qualitatively different steady regimes may occur. The first one is a refraction-like behavior obtained at small incidence angles when the jet crosses the film and is deflected by the film-jet interaction. For larger incidence angles, the jet is absorbed by the film, giving rise to a new class of flow in which the jet undulates along the film with a characteristic wavelength. Besides its fundamental interest, this study presents a new way to guide a micro-metric flow of liquid in the inertial regime and to probe foam stability submitted to violent perturbations at the soap film scale.

  14. Radio polarization study in protostellar jet

    E-Print Network [OSTI]

    Cécere, Mariana; Araudo, Anabella T; De Colle, Fabio; Esquivel, Alejandro; Carrasco-González, Carlos; Rodríguez, Luis F

    2015-01-01T23:59:59.000Z

    Synchrotron radiation is commonly observed associated with shocks of different velocities, ranging from relativistic shocks associated with, e.g., active galactic nuclei, gamma-ray bursts or microquasars to weakly- or non-relativistic flows as those observed e.g. in supernovae and supernova remnants. Recent observations of polarization in protostellar jets are important not only because they extend the range over which the acceleration process works, but also because they allow to measure directly the jet and interstellar magnetic field structure and intensity, thus giving insights on the jet ejection mechanism itself. In this paper, we compute for the first time polarized (synchrotron) and non polarized (thermal-X-ray) synthetic emission maps from axisymmetrical simulations of magnetized protostellar jets. We consider models with different jet velocities and variability, as well as models with toroidal or helical magnetic field. Our simulations show that variable, low-density jets with velocities ~ 1000km/s ...

  15. Jet Fragmentation via Recombination of Parton Showers

    E-Print Network [OSTI]

    Kyong Chol Han; Rainer J Fries; Che Ming Ko

    2012-09-05T23:59:59.000Z

    We study hadron production in jets by applying quark recombination to jet shower partons. With the jet showers obtained from PYTHIA and augmented by additional non-perturbative effects, we compute hadron spectra in e+ + e-collisions at sqrt(s)=200 GeV. Including contributions from resonance decays, we find that the resulting transverse momentum spectra for pions, kaons, and protons reproduce reasonably those from the string fragmentation as implemented in PYTHIA.

  16. Jet physics in Run 2 at CDF

    SciTech Connect (OSTI)

    Field, R.; /Florida U.

    2005-01-01T23:59:59.000Z

    New CDF Run 2 results on the inclusive jet cross section (K{sub T} algorithm) and the b-jet cross section (MidPoint algorithm) are presented and compared with theory. We also study the ''underlying event'' by using the direction of the leading jet to isolate regions of {eta}-{phi} space that are very sensitive to the ''beam-beam'' remnants and to multiple parton interactions.

  17. NSPWG-recommended safety requirements and guidelines for SEI nuclear propulsion

    SciTech Connect (OSTI)

    Marshall, A.C.; Sawyer, J.C. Jr.; Bari, R.A.; Brown, N.W.; Cullingford, H.S.; Hardy, A.C.; Lee, J.H.; Mcculloch, W.H.; Niederauer, G.F.; Remp, K. (Sandia National Laboratories, Albuquerque, NM (United States) NASA, Washington (United States) Brookhaven National Laboratory, Upton, NY (United States) General Electric Co., San Jose, CA (United States) NASA, Johnson Space Center, Houston, Tn (United States) L

    1992-07-01T23:59:59.000Z

    An interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top-level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of safety functional requirements. In addition, the NSPWG reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. Safety requirements were developed for reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, and safeguards. Guidelines were recommended for risk/reliability, operational safety, flight trajectory and mission abort, space debris and meteoroids, and ground test safety. In this paper the specific requirements and guidelines will be discussed. 9 refs.

  18. NSPWG-recommended safety requirements and guidelines for SEI nuclear propulsion

    SciTech Connect (OSTI)

    Marshall, A.C.; Lee, J.H.; McCulloch, W.H. (Sandia National Labs., Albuquerque, NM (United States)); Sawyer, J.C. Jr. (National Aeronautics and Space Administration, Washington, DC (United States)); Bari, R.A. (Brookhaven National Lab., Upton, NY (United States)); Brown, N.W. (General Electric Co., San Jose, CA (United States)); Cullingford, H.S.; Hardy, A.C. (National Aeronautics and Space Administ

    1992-01-01T23:59:59.000Z

    An Interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top- level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition the NSPWG reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. Safety requirements were developed for reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, and safeguards. Guidelines were recommended for risk/reliability, operational safety, flight trajectory and mission abort, space debris and meteoroids, and ground test safety. In this paper the specific requirements and guidelines will be discussed.

  19. NSPWG-recommended safety requirements and guidelines for SEI nuclear propulsion

    SciTech Connect (OSTI)

    Marshall, A.C.; Lee, J.H.; McCulloch, W.H. [Sandia National Labs., Albuquerque, NM (United States); Sawyer, J.C. Jr. [National Aeronautics and Space Administration, Washington, DC (United States); Bari, R.A. [Brookhaven National Lab., Upton, NY (United States); Brown, N.W. [General Electric Co., San Jose, CA (United States); Cullingford, H.S.; Hardy, A.C. [National Aeronautics and Space Administration, Houston, TX (United States). Lyndon B. Johnson Space Center; Niederauer, G.F. [Los Alamos National Lab., NM (United States); Remp, K. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Rice, J.W. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Sholtis, J.A. [Department of the Air Force, Kirtland AFB, NM (United States)

    1992-09-01T23:59:59.000Z

    An Interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top- level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition the NSPWG reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. Safety requirements were developed for reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, and safeguards. Guidelines were recommended for risk/reliability, operational safety, flight trajectory and mission abort, space debris and meteoroids, and ground test safety. In this paper the specific requirements and guidelines will be discussed.

  20. Nuclear Composition of Magnetized GRB Jets

    E-Print Network [OSTI]

    Shibata, Sanshiro

    2015-01-01T23:59:59.000Z

    We investigate the fraction of metal nuclei in the relativistic jets of gamma-ray bursts associated with core-collapse supernovae. We simulate the fallback in jet-induced explosions with two-dimensional relativistic hydrodynamics calculations and the jet acceleration with steady, radial, relativistic magnetohydrodynamics calculations, and derive detail nuclear composition of the jet by postprocessing calculation. We found that if the temperature at the jet launch site is above $4.7\\times 10^9$K, quasi-statistical equilibrium (QSE) is established and heavy nuclei are dissociated to light particles such as $^4$He during the acceleration of the jets. The criterion for the survival of metal nuclei is written in terms of the isotropic jet luminosity as $L_{\\rm j}^{\\rm iso} \\lesssim 3.9\\times 10^{50}(R_{\\rm i}/10^7{\\rm cm})^2 (1+\\sigma_{\\rm i})~{\\rm erg~s^{-1}}$, where $R_{\\rm i}$ and $\\sigma_{\\rm i}$ are the initial radius of the jets and the initial magnetization parameter, respectively. If the jet is initially d...

  1. Increasing jet entrainment, mixing and spreading

    DOE Patents [OSTI]

    Farrington, Robert B. (Wheatridge, CO)

    1994-01-01T23:59:59.000Z

    A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

  2. Increasing jet entrainment, mixing and spreading

    DOE Patents [OSTI]

    Farrington, R.B.

    1994-08-16T23:59:59.000Z

    A free jet of air is disturbed at a frequency that substantially matches natural turbulences in the free jet to increase the entrainment, mixing, and spreading of air by the free jet, for example in a room or other enclosure. The disturbances are created by pulsing the flow of air that creates the free jet at the desired frequency. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 11 figs.

  3. Jet Substructure at the Large Hadron Collider

    E-Print Network [OSTI]

    Christopher K. Vermilion

    2011-01-07T23:59:59.000Z

    I explore many aspects of jet substructure at the Large Hadron Collider, ranging from theoretical techniques for jet calculations, to phenomenological tools for better searches with jets, to software for implementing and comparing such tools. I begin with an application of soft-collinear effective theory, an effective theory of QCD applied to high-energy quarks and gluons. This material is taken from Ref. 1, in which we demonstrate factorization and logarithmic resummation for a certain class of observables in electron-positron collisions. I then explore various phenomenological aspects of jet substructure in simulated events. After observing numerous features of jets at hadron colliders, I describe a method -- jet pruning -- for improving searches for heavy particles that decay to one or more jets. This material is a greatly expanded version of Ref. 2. Finally, I give an overview of the software tools available for these kinds of studies, with a focus on SpartyJet, a package for implementing and comparing jet-based analyses I have collaborated on. Several detailed calculations and software examples are given in the appendices. Sections with no new content are italic in the Table of Contents.

  4. Jet substructures of boosted polarized top quarks

    E-Print Network [OSTI]

    Yoshio Kitadono; Hsiang-nan Li

    2014-09-05T23:59:59.000Z

    We study jet substructures of a boosted polarized top quark, which undergoes the semileptonic decay $t\\to b\\ell\

  5. PHYSICAL PARAMETERS OF STANDARD AND BLOWOUT JETS

    SciTech Connect (OSTI)

    Pucci, Stefano; Romoli, Marco [Department of Physics and Astronomy, University of Firenze, I-50121 Firenze (Italy); Poletto, Giannina [INAF-Arcetri Astrophysical Observatory, I-50125 Firenze (Italy); Sterling, Alphonse C., E-mail: stpucci@arcetri.astro.it [Space Science Office, NASA/MSFC, Huntsville, Al 35812 (United States)

    2013-10-10T23:59:59.000Z

    The X-ray Telescope on board the Hinode mission revealed the occurrence, in polar coronal holes, of much more numerous jets than previously indicated by the Yohkoh/Soft X-ray Telescope. These plasma ejections can be of two types, depending on whether they fit the standard reconnection scenario for coronal jets or if they include a blowout-like eruption. In this work, we analyze two jets, one standard and one blowout, that have been observed by the Hinode and STEREO experiments. We aim to infer differences in the physical parameters that correspond to the different morphologies of the events. To this end, we adopt spectroscopic techniques and determine the profiles of the plasma temperature, density, and outflow speed versus time and position along the jets. The blowout jet has a higher outflow speed, a marginally higher temperature, and is rooted in a stronger magnetic field region than the standard event. Our data provide evidence for recursively occurring reconnection episodes within both the standard and the blowout jet, pointing either to bursty reconnection or to reconnection occurring at different locations over the jet lifetimes. We make a crude estimate of the energy budget of the two jets and show how energy is partitioned among different forms. Also, we show that the magnetic energy that feeds the blowout jet is a factor of 10 higher than the magnetic energy that fuels the standard event.

  6. Detailed characterization of jets in heavy ion collisions using jet fragmentation functions

    E-Print Network [OSTI]

    Ma, Frank Teng

    2013-01-01T23:59:59.000Z

    In this thesis the jet fragmentation function of inclusive jets with transverse momentum PT > 100 GeV/c in PbPb collisions is measured for reconstructed charged particles with PT > 1 GeV/c within the jet cone. A data sample ...

  7. The X-ray Jet in Centaurus A: Clues on the Jet Structure and Particle Acceleration

    E-Print Network [OSTI]

    Jun Kataoka; Lukasz Stawarz; Felix Aharonian; Fumio Takahara; Michal Ostrowski; Philip G. Edwards

    2005-12-10T23:59:59.000Z

    We report detailed studies of the X-ray emission from the kpc scale jet in the nearest active galaxy, Cen A. 41 compact sources were found within the jet, 13 of which were newly identified. We construct the luminosity function for the detected jet-knots and argue that the remaining emission is most likely to be truly diffuse, rather than resulting from the pile-up of unresolved faint knots. The transverse jet profile reveals that the extended emission has the intensity peak at the jet boundaries. We note that limb-brightened jet morphologies have been observed previously at radio frequencies in some jet sources, but never so clearly at higher photon energies. Our result therefore supports a stratified jet model, consisting of a relativistic outflow including a boundary layer with a velocity shear. In addition, we found that the X-ray spectrum of the diffuse component is almost uniform across and along the jet. We discuss this spectral behavior within a framework of shock and stochastic particle acceleration processes. We note some evidence for a possible spectral hardening at the outer sheath of the jet. Due to the limited photon statistics of the present data, further deep observations of Cen A are required to determine the reality of this finding, however we note that the existence of the hard X-ray features at outer jet boundaries would provide an important challenge to theories for the evolution of ultra-relativistic particles within the jets.

  8. Drying characteristics of slot jet reattachment nozzle and comparison with a slot jet nozzle

    E-Print Network [OSTI]

    Alam, Syed Aftab

    1998-01-01T23:59:59.000Z

    Slot Jet Reattachment (SJR) nozzle is an extension of hics.the Radial Jet Reattachment (RJR) concept used to provide high heat and mass transfer while allowing for the control of flow exerted force on the reattachment surface. The SJR is a slot jet...

  9. MHD jet propagation in the case of DG Tau

    E-Print Network [OSTI]

    Vaidya, Bhargav; Rubini, Francesco; de Colle, Fabio

    2010-01-01T23:59:59.000Z

    of art telescopes. Usually jets are observed in forbiddenlike SII, OII etc. One of the jet studied in great detailsis the DG Tau jet. (Lavalley-Fouquet et al. (2000), Dougados

  10. Jet Schemes and Truncated Wedge Schemes Cornelia O. Yuen

    E-Print Network [OSTI]

    Smith, Karen E.

    Jet Schemes and Truncated Wedge Schemes by Cornelia O. Yuen A dissertation submitted in partial of jets and arcs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 A higher dimension analog of arcs and jets . . . . . . . . . . . . . . . . . . . 3 1.3 History

  11. Excitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest to propulsion research

    E-Print Network [OSTI]

    Choueiri, Edgar

    it is thus necessary to heat these ions considerably. Various types of electrodeless plasma heating provideExcitation and propagation of Electrostatic Ion Cyclotron waves in rf-sustained plasmas of interest to propulsion research Rostislav Spektor and Edgar Y. Choueiri Electric Propulsion and Plasma Dynamics

  12. IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 2095 Permanent Magnet Helicon Source for Ion Propulsion

    E-Print Network [OSTI]

    Chen, Francis F.

    IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 36, NO. 5, OCTOBER 2008 2095 Permanent Magnet Helicon Source for Ion Propulsion Francis F. Chen, Life Fellow, IEEE Abstract--Helicon sources have been proposed by at least two groups for generating ions for space propulsion: the Helicon Dou- ble Layer Thruster (HDLT

  13. The CU Aerospace / VACCO Propulsion Unit for CubeSats (PUC) is a complete high-performance and

    E-Print Network [OSTI]

    Carroll, David L.

    such as solar panels and magnetic torquers. For increased performance, or to meet customer specific missionThe CU Aerospace / VACCO Propulsion Unit for CubeSats (PUC) is a complete high necessary propulsion subsystems, including controller, power processing unit, micro-cavity discharge

  14. Detailed kinetic computations and experiments for the choice of a fuel-oxidiser couple for hybrid propulsion.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the heat diffusion in the solid. Time variations are possible in the system. The control of injection valve for hybrid propulsion. N. Gascoina* , P. Gillarda , A. Mangeota , A. Navarro-Rodrigueza a PRISME Institute of a solid reducer for hybrid propulsion is generally based on the quantity of gaseous combustible it can

  15. Problems in developing bimodal space power and propulsion system fuel element

    SciTech Connect (OSTI)

    Nikolaev, Yu. V.; Gontar, A. S.; Zaznoba, V. A.; Parshin, N. Ya.; Ponomarev-Stepnoi, N. N.; Usov, V. A. [Research Institute of SIA 'Lutch' Podolsk, Moscow Region, 142100 (Russian Federation); RRC 'Kurchatov Institute' Moscow, 123182 (Russian Federation)

    1997-01-10T23:59:59.000Z

    The paper discusses design of a space nuclear power and propulsion system fuel element (PPFE) developed on the basis of an enhanced single-cell thermionic fuel element (TFE) of the 'TOPAZ-2' thermionic converter-reactor (TCR), and presents the PPFE performance for propulsion and power modes of operation. The choice of UC-TaC fuel composition is substantiated. Data on hydrogen effect on the PPFE output voltage are presented, design solutions are considered that allow to restrict hydrogen supply to an interelectrode gap (IEG). Long-term geometric stability of an emitter assembly is supported by calculated data.

  16. Electron cyclotron resonant multicusp magnetic field microwave plasma source for electric propulsion

    SciTech Connect (OSTI)

    Dahimene, M.; Mahoney, L.; Asmussen, J.

    1987-05-01T23:59:59.000Z

    The development of electrodeless microwave ion and plasma sources has been a recent, very active research project at Michigan State University. The results are efficient, compact microwave discharge configurations that operate at low pressures (0.5 mtorr to 100 mtorr) and efficiently produce low energy ions and free radicals and broad ion beams for oxidation, deposition, and etching experiments. The microwave discharge technology developed for these applications may be useful for application in electric propulsion. This paper reviews this microwave applicator technology and indicates how it may be extended to higher power levels and applied to electric propulsion systems. 12 references.

  17. Small Reactor Designs Suitable for Direct Nuclear Thermal Propulsion: Interim Report

    SciTech Connect (OSTI)

    Bruce G. Schnitzler

    2012-01-01T23:59:59.000Z

    Advancement of U.S. scientific, security, and economic interests requires high performance propulsion systems to support missions beyond low Earth orbit. A robust space exploration program will include robotic outer planet and crewed missions to a variety of destinations including the moon, near Earth objects, and eventually Mars. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and the Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. In NASA's recent Mars Design Reference Architecture (DRA) 5.0 study, nuclear thermal propulsion (NTP) was again selected over chemical propulsion as the preferred in-space transportation system option for the human exploration of Mars because of its high thrust and high specific impulse ({approx}900 s) capability, increased tolerance to payload mass growth and architecture changes, and lower total initial mass in low Earth orbit. The recently announced national space policy2 supports the development and use of space nuclear power systems where such systems safely enable or significantly enhance space exploration or operational capabilities. An extensive nuclear thermal rocket technology development effort was conducted under the Rover/NERVA, GE-710 and ANL nuclear rocket programs (1955-1973). Both graphite and refractory metal alloy fuel types were pursued. The primary and significantly larger Rover/NERVA program focused on graphite type fuels. Research, development, and testing of high temperature graphite fuels was conducted. Reactors and engines employing these fuels were designed, built, and ground tested. The GE-710 and ANL programs focused on an alternative ceramic-metallic 'cermet' fuel type consisting of UO2 (or UN) fuel embedded in a refractory metal matrix such as tungsten. The General Electric program examined closed loop concepts for space or terrestrial applications as well as open loop systems for direct nuclear thermal propulsion. Although a number of fast spectrum reactor and engine designs suitable for direct nuclear thermal propulsion were proposed and designed, none were built. This report summarizes status results of evaluations of small nuclear reactor designs suitable for direct nuclear thermal propulsion.

  18. Self-propulsion of a spherical electric or magnetic microbot in a polar viscous fluid

    E-Print Network [OSTI]

    Felderhof, B U

    2014-01-01T23:59:59.000Z

    The self-propulsion of a sphere immersed in a polar liquid or ferrofluid is studied on the basis of ferrohydrodynamics. In the electrical case an oscillating charge density located inside the sphere generates an electrical field which polarizes the fluid. The lag of polarization with respect to the electrical field due to relaxation generates a time-independent electrical torque density acting on the fluid causing it to move. The resulting propulsion velocity of the sphere is calculated in perturbation theory to second order in powers of the charge density.

  19. Ground Test Facility for Propulsion and Power Modes of Nuclear Engine Operation

    SciTech Connect (OSTI)

    Michael, WILLIAMS

    2004-11-22T23:59:59.000Z

    Existing DOE Ground Test Facilities have not been used to support nuclear propulsion testing since the Rover/NERVA programs of the 1960's. Unlike the Rover/NERVA programs, DOE Ground Test facilities for space exploration enabling nuclear technologies can no longer be vented to the open atmosphere. The optimal selection of DOE facilities and accompanying modifications for confinement and treatment of exhaust gases will permit the safe testing of NASA Nuclear Propulsion and Power devices involving variable size and source nuclear engines for NASA Jupiter Icy Moon Orbiter (JIMO) and Commercial Space Exploration Missions with minimal cost, schedule and environmental impact. NASA site selection criteria and testing requirements are presented.

  20. air jet indentation: Topics by E-print Network

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

    will take an important place for fluid control. Micro air jets are characterized by their speed, frequency and tilt. Usually, this micro air jets are produced by fluidic...

  1. abrasive water jet: Topics by E-print Network

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

    to extend the current knowledge of abrasive water jets, by determining the kinetic energy distribution, kinetic energy distribution. NOMENCLATURE AWJ Abrasive water jet CD...

  2. Why Do Disks Form Jets?

    E-Print Network [OSTI]

    D Lynden-Bell

    2002-03-27T23:59:59.000Z

    It is argued that jet modelers have given insufficient study to the natural magneto-static configurations of field wound up in the presence of a confining general pressure. Such fields form towers whose height grows with each twist at a velocity comparable to the circular velocity of the accretion disk that turns them. A discussion of the generation of such towers is preceded by a brief history of the idea that quasars, active galaxies, and galactic nuclei contain giant black holes with accretion disks.

  3. Jet quenching from the lattice

    E-Print Network [OSTI]

    Marco Panero; Kari Rummukainen; Andreas Schäfer

    2014-07-10T23:59:59.000Z

    We present a lattice study of the momentum broadening experienced by a hard parton in the quark-gluon plasma. In particular, the contributions to this real-time phenomenon from soft modes are extracted from a set of gauge-invariant operators in a dimensionally reduced effective theory (electrostatic QCD), which can be simulated on a Euclidean lattice. At the temperatures accessible to present experiments, the soft contributions to the jet quenching parameter are found to be quite large. We compare our results to phenomenological models and to holographic computations.

  4. Viscous boundary layers of radiation-dominated, relativistic jets. II. The free-streaming jet model

    E-Print Network [OSTI]

    Coughlin, Eric R

    2015-01-01T23:59:59.000Z

    We analyze the interaction of a radiation-dominated jet and its surroundings using the equations of radiation hydrodynamics in the viscous limit. In a previous paper we considered the two-stream scenario, which treats the jet and its surroundings as distinct media interacting through radiation viscous forces. Here we present an alternative boundary layer model, known as the free-streaming jet model -- where a narrow stream of fluid is injected into a static medium -- and present solutions where the flow is ultrarelativistic and the boundary layer is dominated by radiation. It is shown that these jets entrain material from their surroundings and that their cores have a lower density of scatterers and a harder spectrum of photons, leading to observational consequences for lines of sight that look "down the barrel of the jet." These jetted outflow models may be applicable to the jets produced during long gamma-ray bursts and super-Eddington phases of tidal disruption events.

  5. Miniconference on astrophysical jets P. M. Bellan

    E-Print Network [OSTI]

    Bellan, Paul M.

    of Technology, Pasadena, California 91125 Received 24 January 2005; accepted 25 February 2005; published online simulations of jets can also be produced by other means besides spheromak technology. In particular, high power pulse lasers can pro- duce hydrodynamically driven jets and Z-pinch wire arrays can produce both

  6. Jet measurements in the STAR experiment

    E-Print Network [OSTI]

    Elena Bruna; for the STAR Collaboration

    2011-10-12T23:59:59.000Z

    Jets are produced from hard scatterings in the early stages of heavy-ion collisions, therefore they can be exploited as probes for medium tomography. Such high-$p_T$ partons are expected to suffer energy loss in the hot and dense nuclear medium via gluon radiation or elastic collisions along their path. Jet reconstruction gives access to the kinematics of the hard scattering that produced the jet, improving our understanding of energy loss and its effect on the jet structure. Such measurements are challenging in heavy-ion collisions at RHIC, due to the large background, therefore a precise characterization of the background in Au+Au is needed. We present an overview of the results on jet measurements obtained by the STAR experiment in p+p, d+Au and central Au+Au collisions at 200 GeV. We also present results obtained with reconstructed di-jets and jet-hadron correlations as tools to study the medium effects on jet production.

  7. Jet-hadron correlations in STAR

    E-Print Network [OSTI]

    Alice Ohlson; for the STAR Collaboration

    2011-06-30T23:59:59.000Z

    Advancements in full jet reconstruction have made it possible to use jets as triggers in azimuthal angular correlations to study the modification of hard-scattered partons in the medium created in ultrarelativistic heavy-ion collisions. This increases the range of parton energies accessible in these analyses and improves the signal-to-background ratio compared to dihadron correlations. Results of a systematic study of jet-hadron correlations in central Au-Au collisions at sqrt(s_NN) = 200 GeV are indicative of a broadening and softening of jets which interact with the medium. Furthermore, jet-hadron correlations suggest that the suppression of the associated hadron yield at high-pT is balanced in large part by low-pT enhancement.

  8. $W/Z$ + jets results from CDF

    SciTech Connect (OSTI)

    Camarda, Stefano; /Barcelona, IFAE

    2010-01-01T23:59:59.000Z

    The CDF Collaboration has a comprehensive program of studying the production of vector bosons, W and Z, in association with energetic jets. Excellent understanding of the standard model W/Z+jets and W/Z+c,b-jets processes is of paramount importance for the top quark physics and for the Higgs boson and many new physics searches. We review the latest CDF results on Z-boson production in association with inclusive and b-quark jets, study of the p{sub T} balance in Z+jet events, and a measurement of the W+charm production cross section. The results are based on 4-5 fb{sup -1} of data and compared to various Monte Carlo and next-to-leading order perturbative QCD predictions.

  9. Can Protostellar Jets Drive Supersonic Turbulence in Molecular Clouds?

    E-Print Network [OSTI]

    Robi Banerjee; Ralf S. Klessen; Christian Fendt

    2007-06-25T23:59:59.000Z

    Jets and outflows from young stellar objects are proposed candidates to drive supersonic turbulence in molecular clouds. Here, we present the results from multi-dimensional jet simulations where we investigate in detail the energy and momentum deposition from jets into their surrounding environment and quantify the character of the excited turbulence with velocity probability density functions. Our study include jet--clump interaction, transient jets, and magnetised jets. We find that collimated supersonic jets do not excite supersonic motions far from the vicinity of the jet. Supersonic fluctuations are damped quickly and do not spread into the parent cloud. Instead subsonic, non-compressional modes occupy most of the excited volume. This is a generic feature which can not be fully circumvented by overdense jets or magnetic fields. Nevertheless, jets are able to leave strong imprints in their cloud structure and can disrupt dense clumps. Our results question the ability of collimated jets to sustain supersonic turbulence in molecular clouds.

  10. An inkjet vision measurement technique for high-frequency jetting

    SciTech Connect (OSTI)

    Kwon, Kye-Si, E-mail: kskwon@sch.ac.kr; Jang, Min-Hyuck; Park, Ha Yeong [Department of Mechanical Engineering, Soonchunhyang University 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of); Ko, Hyun-Seok [Department of Electrical and Robot Engineering, Soonchunhyang University, 22, Soonchunhyang-Ro, Shinchang, Asan Chungnam 336-745 (Korea, Republic of)

    2014-06-15T23:59:59.000Z

    Inkjet technology has been used as manufacturing a tool for printed electronics. To increase the productivity, the jetting frequency needs to be increased. When using high-frequency jetting, the printed pattern quality could be non-uniform since the jetting performance characteristics including the jetting speed and droplet volume could vary significantly with increases in jet frequency. Therefore, high-frequency jetting behavior must be evaluated properly for improvement. However, it is difficult to measure high-frequency jetting behavior using previous vision analysis methods, because subsequent droplets are close or even merged. In this paper, we present vision measurement techniques to evaluate the drop formation of high-frequency jetting. The proposed method is based on tracking target droplets such that subsequent droplets can be excluded in the image analysis by focusing on the target droplet. Finally, a frequency sweeping method for jetting speed and droplet volume is presented to understand the overall jetting frequency effects on jetting performance.

  11. Solar power-propulsion plant using heat accumulators of solar energy

    SciTech Connect (OSTI)

    Popov, E.B.; Salnikov, V.A.; Fedik, I.I. [Scientific Production Association ``Lutch``, Podolsk, Moscow Region (Russia)

    1996-03-01T23:59:59.000Z

    This work covers the concept of a power-propulsion plant (PPP) for spacecraft. The PPP is intended: (a) to transport a spacecraft from one orbit to another to perform the spacecraft tasks; (b) to provide the spacecraft with electric power. {copyright} {ital 1996 American Institute of Physics.}

  12. Rsum--La pile combustible est une technologie alternative pour la propulsion des vhicules lectriques.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Résumé-- La pile ŕ combustible est une technologie alternative pour la propulsion des véhicules...) pour assurer l'alimentation et la gestion de l'hydrogčne et de l'air. Un modčle du générateur ŕ pile ŕ standard utilisé dans les applications transport. I. INTRODUCTION La pile ŕ combustible (PAC) est un

  13. National Aeronautics and Space Administration In-Space propulSIon SyStemS roadmap

    E-Print Network [OSTI]

    Waliser, Duane E.

    National Aeronautics and Space Administration In-Space propulSIon SyStemS roadmap Technology Area Missions TA02-24 Acknowledgements TA02-24 #12;Foreword NASA's integrated technology roadmap, including both Roadmap, an integrated set of fourteen technology area roadmaps, recommending the overall technology

  14. Modeling the Characteristics of Propulsion Systems Providing Less Than 10 N Thrust

    E-Print Network [OSTI]

    . Chiasson, Paulo C. Lozano May 2012 SSL#8-12 1 #12;2 #12;Modeling the Characteristics of Propulsion Systems Providing Less Than 10 N Thrust Thomas M. Chiasson, Paulo C. Lozano May 2012 SSL#8-12 1 1 This work is based

  15. A Flux-Limited Numerical Method for the MHD Equations to Simulate Propulsive Plasma Flows

    E-Print Network [OSTI]

    Choueiri, Edgar

    to be effective tools in plasma propulsion research, a higher order accu- rate solver that captures MHD shocks approach, numerical simulations are valuable tools in plasma thruster research. More- over, simulations can Simula- tions The importance of numerical simulation in advancing plasma thruster research was realized

  16. Importance of Nuclear DataImportance of Nuclear Data to the Naval Nuclear Propulsion Program

    E-Print Network [OSTI]

    Danon, Yaron

    Importance of Nuclear DataImportance of Nuclear Data to the Naval Nuclear Propulsion Program Don Cores · Project Prometheus · Some Very Recent Criticality Analyses #12;Use of Early RPI Measurements · Criticality Analyses of Under-moderated Systemsy y y · Most Reactive Condition ­ Highest Water Density

  17. Passive Robotic Models of Propulsion by the Bodies and Caudal Fins of Fish

    E-Print Network [OSTI]

    Lauder, George V.

    SYMPOSIUM Passive Robotic Models of Propulsion by the Bodies and Caudal Fins of Fish George V, freely-swimming fishes. In this article, we discuss the use of simple robotic models of flexing fish/or pitch motion using a robotic flapping controller that allowed moving foils to swim at their self

  18. MRI-based Microrobotic system for the Propulsion and Navigation of Ferromagnetic Microcapsules

    E-Print Network [OSTI]

    Boyer, Edmond

    MRI-based Microrobotic system for the Propulsion and Navigation of Ferromagnetic Microcapsules 3-D navigation of a microdevice in blood ves- sels, namely: (i) vessel path planner, (ii) magnetic, magnetic resonance imaging, minimally invasive interventions, real-time control Email address: antoine

  19. IEPC paper-01-060, 27th International Electric Propulsion Conference,

    E-Print Network [OSTI]

    IEPC paper-01-060, 27th International Electric Propulsion Conference, Pasadena, CA, October 2001 potential drop in the fringing magnetic field outside the thruster channel. In this paper we investigate is almost not sensitive to changes of the electrode potential, but depends on the magnetic field

  20. A review of the Los Alamos effort in the development of nuclear rocket propulsion

    SciTech Connect (OSTI)

    Durham, F.P.; Kirk, W.L.; Bohl, R.J.

    1991-01-01T23:59:59.000Z

    This paper reviews the achievements of the Los Alamos nuclear rocket propulsion program and describes some specific reactor design and testing problems encountered during the development program along with the progress made in solving these problems. The relevance of these problems to a renewed nuclear thermal rocket development program for the Space Exploration Initiative (SEI) is discussed. 11 figs.

  1. Research, development, and demonstration of lead-acid batteries for electric vehicle propulsion. Annual report, 1980

    SciTech Connect (OSTI)

    Not Available

    1981-03-01T23:59:59.000Z

    The progress and status of Eltra's Electric Vehicle Battery Program during FY-80 are presented under five divisional headings: Research on Components and Processes; Development of Cells and Modules for Electric Vehicle Propulsion; Sub-Systems; Pilot Line Production of Electric Vehicle Battery Prototypes; and Program Management.

  2. A Critical History of Electric Propulsion: The First Fifty Years (1906-1956)

    E-Print Network [OSTI]

    Choueiri, Edgar

    m = Propellant mass flow rate P = Input electric power p P/Mv = Input electric power per unit Physics Group, MAE Department. e-mail: choueiri@princeton.edu. Presented at the 40th AIAA/ASME by the AIAA with permission. Also published in the Journal of Propulsion and Power, Vol. 20, No. 2, pp. 193

  3. Atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM)

    1999-01-01T23:59:59.000Z

    Atmospheric-pressure plasma jet. A .gamma.-mode, resonant-cavity plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two concentric cylindrical electrodes are employed to generate a plasma in the annular region therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly shaping the rf-powered electrode. Because of the atmospheric pressure operation, no ions survive for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike low-pressure plasma sources and conventional plasma processing methods.

  4. Water jet rebounds on hydrophobic surfaces : a first step to jet micro-fluidics

    E-Print Network [OSTI]

    Franck Celestini; R. Kofman; Xavier Noblin; Mathieu Pellegrin

    2010-09-28T23:59:59.000Z

    When a water jet impinges upon a solid surface it produces a so called hydraulic jump that everyone can observe in the sink of its kitchen. It is characterized by a thin liquid sheet bounded by a circular rise of the surface due to capillary and gravitational forces. In this phenomenon, the impact induces a geometrical transition, from the cylindrical one of the jet to the bi-dimensional one of the film. A true jet rebound on a solid surface, for which the cylindrical geometry is preserved, has never been yet observed. Here we experimentally demonstrate that a water jet can impact a solid surface without being destabilized. Depending on the incident angle of the impinging jet, its velocity and the degree of hydrophobicity of the substrate, the jet can i) bounce on the surface with a fixed reflected angle, ii) land on it and give rise to a supported jet or iii) be destabilized, emitting drops. Capillary forces are predominant at the sub-millimetric jet scale considered in this work, along with the hydrophobic nature of the substrate. The results presented in this letter raise the fundamental problem of knowing why such capillary hydraulic jump gives rise to this unexpected jet rebound phenomenon. This study furthermore offers new and promising possibilities to handle little quantity of water through "jet micro-fluidics"

  5. Experimental studies of unbiased gluon jets from $e^{+}e^{-}$ annihilations using the jet boost algorithm

    E-Print Network [OSTI]

    Abbiendi, G; Ĺkesson, P F; Alexander, G; Allison, J; Amaral, P; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Büsser, K; Burckhart, H J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, Akos; Cuffiani, M; Dado, S; de Roeck, A; De Wolf, E A; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karlen, Dean A; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kormos, L L; Kramer, T; Krieger, P; Von Krogh, J; Krüger, K; Kühl, T; Kupper, M; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Layter, J G; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; MacPherson, A; Mader, W; Marcellini, S; Martin, A J; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Poli, B; Polok, J; Pooth, O; Przybycien, M B; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rosati, S; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Tran, P; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2004-01-01T23:59:59.000Z

    We present the first experimental results based on the jet boost algorithm, a technique to select unbiased samples of gluon jets in e+e- annihilations, i.e. gluon jets free of biases introduced by event selection or jet finding criteria. Our results are derived from hadronic Z0 decays observed with the OPAL detector at the LEP e+e- collider at CERN. First, we test the boost algorithm through studies with Herwig Monte Carlo events and find that it provides accurate measurements of the charged particle multiplicity distributions of unbiased gluon jets for jet energies larger than about 5 GeV, and of the jet particle energy spectra (fragmentation functions) for jet energies larger than about 14 GeV. Second, we apply the boost algorithm to our data to derive unbiased measurements of the gluon jet multiplicity distribution for energies between about 5 and 18 GeV, and of the gluon jet fragmentation function at 14 and 18 GeV. In conjunction with our earlier results at 40 GeV, we then test QCD calculations for the en...

  6. Jet Flows Around Microbubbles In Subcooled Boiling , Xiaofeng Pengb

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    Jet Flows Around Microbubbles In Subcooled Boiling Hao Wanga , Xiaofeng Pengb , David M Strong jet flows were observed emanating from micro bubbles on a 100 µm diameter wire during subcooled analysis. The bubble-top jet flows were characterized by a single jet at the bubble top. Both experiments

  7. JET: an Opportunity for the U.S. in the

    E-Print Network [OSTI]

    JET: an Opportunity for the U.S. in the Coming Decade Brett E. Chapman University of Wisconsin, 2000 #12;Introduction -- Premise: JET represents the only opportunity for the U.S. to experimentally issues accessible in JET in the near term -- Also feeds into Question #4: JET DT experiments should

  8. Jet production in ep collisions Pierre Van Mechelen

    E-Print Network [OSTI]

    Jet production in ep collisions Pierre Van Mechelen University of Antwerpen Pierre Outline: Introduction Inclusive jet photoproduction Dijet electroproduction Inclusve jet electroproduction #12; Jet production in ep collisions Pierre Van Mechelen HERA, H1 and ZEUS H1 ZEUS p (920 GeV) e

  9. Jet Reconstruction in Heavy Ion Collisions

    E-Print Network [OSTI]

    Sevil Salur

    2009-05-12T23:59:59.000Z

    Measurements of strong suppression of inclusive hadron distributions and di-hadron correlations at high $p_{T}$, while providing evidence for partonic energy loss, also suffer from geometric biases due to the competition of energy loss and fragmentation. The measurements of fully reconstructed jets is expected to lack these biases as the energy flow is measured independently of the fragmentation details. In this article, we review the recent results from the heavy ion collisions collected by the STAR experiment at RHIC on direct jet reconstruction utilizing the modern sequential recombination and cone jet reconstruction algorithms together with their background subtraction techniques. In order to assess the jet reconstruction biases a comparison with the jet cross section measurement in $\\sqrt{s}=200$ GeV p+p collisions scaled by the number of binary nucleon-nucleon collisions to account for nuclear geometric effects is performed. Comparison of the inclusive jet cross section obtained in central Au+Au events with that in $p+p$ collisions, published previously by STAR, suggests that unbiased jet reconstruction in the complex heavy ion environment indeed may be possible.

  10. Will Jets Identify the Progenitors of Type Ia Supernovae?

    E-Print Network [OSTI]

    Mario Livio; Adam Riess; William Sparks

    2002-04-26T23:59:59.000Z

    We use the fact that a Type Ia supernova has been serendipitously discovered near the jet of the active galaxy 3C 78 to examine the question of whether jets can enhance accretion onto white dwarfs. One interesting outcome of such a jet-induced accretion process is an enhanced rate of novae in the vicinity of jets. We present results of observations of the jet in M87 which appear to have indeed discovered 11 novae in close proximity to the jet. We show that a confirmation of the relation between jets and novae and Type Ia supernovae can finally identify the elusive progenitors of Type Ia supernovae.

  11. Jet physics and the underlying event at the Tevatron

    SciTech Connect (OSTI)

    Field, Rick; /Florida U.

    2005-08-01T23:59:59.000Z

    Tevatron Run 2 results on the inclusive jet cross section (MidPoint and K{sub T} algorithm) and the b-jet and b{bar b}-jet cross section (MidPoint algorithm) are presented and compared with theory. The CDF b-jet {bar b}-jet {Delta}{phi} distribution is compared with theory and with the D0 jet No.1-jet No.2 {Delta}{phi} distribution. The understanding and modeling of the ''underlying event'' in Run 2 at the Tevatron is reviewed and new CDF results are presented.

  12. The interaction between two radial jets

    E-Print Network [OSTI]

    Gruber, Thomas Clifton

    1993-01-01T23:59:59.000Z

    impingement surface pressure coefficient for an impinging radial jet Fig. 4 Impingement surface heat transfer comparison between radial jets and an in-line jet Fig. 5 Two -10 deg RJR nozzles Fig. 6 -10 deg RJR nozzle exit surface tangents Fig. 7 Support... are shown in Fig. 5. The exit radius and exit width were r, = 19 mm and b = 2. 54 mm, respectively. The nozzle was constructed from a standard 25. 4 mm pipe with a 27 mm ID and a 33. 3 mm OD, A ring shaped part formed the top of the nozzle...

  13. Jet spoiler arrangement for wind turbine

    DOE Patents [OSTI]

    Cyrus, Jack D. (Corrales, NM); Kadlec, Emil G. (Albuquerque, NM); Klimas, Paul C. (Albuquerque, NM)

    1985-01-01T23:59:59.000Z

    An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the ends thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby inducing stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

  14. Jet spoiler arrangement for wind turbine

    DOE Patents [OSTI]

    Cyrus, J.D.; Kadlec, E.G.; Klimas, P.C.

    1983-09-15T23:59:59.000Z

    An air jet spoiler arrangement is provided for a Darrieus-type vertical axis wind-powered turbine. Air is drawn into hollow turbine blades through air inlets at the end thereof and is ejected in the form of air jets through small holes or openings provided along the lengths of the blades. The air jets create flow separation at the surfaces of the turbine blades, thereby including stall conditions and reducing the output power. A feedback control unit senses the power output of the turbine and controls the amount of air drawn into the air inlets accordingly.

  15. Jet production in (un)polarized pp collisions: dependence on jet algorithm

    E-Print Network [OSTI]

    Asmita Mukherjee; Werner Vogelsang

    2012-09-09T23:59:59.000Z

    We investigate single-inclusive high-pT jet production in longitudinally polarized pp collisions at RHIC, with particular focus on the algorithm adopted to define the jets. Following and extending earlier work in the literature, we treat the jets in the approximation that they are rather narrow, in which case analytical results for the corresponding next-to-leading order partonic cross sections can be obtained. This approximation is demonstrated to be very accurate for practically all relevant situations, even at Tevatron and LHC energies. We confront results for cross sections and spin-asymmetries based on using cone- and kt-type jet algorithms. We find that jet cross sections at RHIC can differ significantly depending on the algorithm chosen, but that the spin asymmetries are rather robust. Our results are also useful for matching threshold-resummed calculations of jet cross sections to fixed-order ones.

  16. Company Name: JET--the Japan Exchange and Teaching Program Web Site: www.us.emb-japan.go.jp/JET

    E-Print Network [OSTI]

    New Hampshire, University of

    Company Name: JET--the Japan Exchange and Teaching Program Web Site: www.us.emb-japan.go.jp/JET and Teaching (JET) Program is a Japanese Government-sponsored program to improve English language education and promote grass-roots level international exchange in Japan. JET is seeking candidates who will hold

  17. Jet mass spectra in Higgs boson plus one jet at next-to-next-to-leading logarithmic order

    E-Print Network [OSTI]

    Tackmann, Frank J.

    The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using ...

  18. A jet streak circulation associated with a low-latitude jet in the Southern Hemisphere over Africa.

    E-Print Network [OSTI]

    Nicholson, Sharon E.

    A jet streak circulation associated with a low-latitude jet in the Southern Hemisphere over Africa 2007 #12;2 Abstract In the Southern Hemisphere over Africa a mid-tropospheric easterly jet stream exists during some months that is analogous to the African Easterly Jet over West Africa. In this note

  19. Di-jet hadron pair correlation in a hydrodynamical model with a quenching jet

    E-Print Network [OSTI]

    A. K. Chaudhuri

    2008-01-15T23:59:59.000Z

    In jet quenching, a hard QCD parton, before fragmenting into a jet of hadrons, deposits a fraction of its energy in the medium, leading to suppressed production of high-$p_T$ hadrons. Assuming that the deposited energy quickly thermalizes, we simulate the subsequent hydrodynamic evolution of the QGP fluid. Hydrodynamic evolution and subsequent particle emission depend on the jet trajectories. Azimuthal distribution of excess $\\pi^-$ due to quenching jet, averaged over all the trajectories, reasonably well reproduce the di-hadron correlation as measured by the STAR and PHENIX collaboration in central and in peripheral Au+Au collisions.

  20. Drying: a comparison of radial jet reattachment and standard in-line jets

    E-Print Network [OSTI]

    Habetz, Darren Keith

    1991-01-01T23:59:59.000Z

    DRYING; A COMPARISON OF RADIAL JET REATTACHMENT AND STANDARD IN-LINE JETS A Thesis by DARREN KEITH HABETZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE August 1991 Major Subject: Mechanical Engineering DRYING; A COMPARISON OF RADIAL JET REATTACHMENT AND STANDARD IN-LINE JETS A Thesis by DARREN KEITH HABETZ Approved as to style and content by: i2, 4. ~~. Robert H. Page (Chair...

  1. Viscosity and jet quenching from holographic model

    E-Print Network [OSTI]

    Yi-hong Gao; Wei-shui Xu; Ding-fang Zeng

    2007-09-23T23:59:59.000Z

    We consider the backreaction of the fundamental flavor degrees of freedom on the AdS$_5$-Schwarz background, and calculate their contributions to the shear viscosity and jet-quenching parameter of the thermal quark-gluon plasma.

  2. Particle acceleration in electron-ion jets

    E-Print Network [OSTI]

    K. -I. Nishikawa; P. Hardee; C. B. Hededal; G. Richardson; R. Preece; H. Sol; G. J. Fishman; C. Kouvelioutou; Y. Mizuno

    2005-09-20T23:59:59.000Z

    Weibel instability created in collisionless shocks is responsible for particle (electron, positron, and ion) acceleration. Using a 3-D relativistic electromagnetic particle (REMP) code, we have investigated particle acceleration associated with a relativistic electron-ion jet fronts propagating into an ambient plasma without initial magnetic fields with a longer simulation system in order to investigate nonlinear stage of the Weibel instability and its acceleration mechanism. The current channels generated by the Weibel instability induce the radial electric fields. The z component of the Poynting vector (E x B) become positive in the large region along the jet propagation direction. This leads to the acceleration of jet electrons along the jet. In particular the E x B drift with the large scale current channel generated by the ion Weibel instability accelerate electrons effectively in both parallel and perpendicular directions.

  3. Turbulent round jet under gravity waves

    E-Print Network [OSTI]

    Ryu, Yong Uk

    2002-01-01T23:59:59.000Z

    The behavior of a neutrally buoyant horizontal turbulent round jet under a wavy environment was investigated. Progressive waves with different wave amplitudes in an intermediate water depth were used. The Particle Image Velocimetry (PIV) technique...

  4. The Design and Feasibility of a 10 mN Chemical Space Propulsion Alexander Bruccoleri , Paulo Lozano

    E-Print Network [OSTI]

    , Paulo Lozano June 2009 SSL # 3-09 #12;#12;The Design and Feasibility of a 10 mN Chemical Space Propulsion Thruster Alexander Bruccoleri , Paulo Lozano June 2009 SSL # 3-09 This work is based

  5. On the identification and mitigation of life-limiting mechanisms of ionic liquid ion sources envisaged for propulsion of microspacecraft

    E-Print Network [OSTI]

    Brikner, Natalya Anna

    2015-01-01T23:59:59.000Z

    Life-limiting processes affecting ionic liquid ion sources (ILIS) are investigated in this research, motivated by the development of ILIS for propulsion of microspacecraft and other industrial applications. Micropropulsion ...

  6. Heavy element nucleosynthesis in jets from collapsars

    SciTech Connect (OSTI)

    Fujimoto, Shin-ichirou [Department of Electronic Control, Kumamoto National College of Technology, Kumamoto 861-1102 (Japan); Institut d'Astronomie et d'Astrophysique, Universite libre de Bruxelles, CP226 Boulevard du Triomphe, B-1050 Brussels (Belgium); Hashimoto, Masa-aki [Department of Physics, School of Sciences, Kyushu University, Fukuoka 810-8560 (Japan); Kotake, Kei [Division of Theoretical Astronomy, National Astronomical Observatory Japan, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Yamada, Shoichi [Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Advanced Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2007-02-26T23:59:59.000Z

    We investigate nucleosynthesis in collapsars, based on long-term, magnetohydrodynamic simulations of a rapidly rotating massive star of 40M{center_dot} during the core collapse. We have calculated detailed composition of magnetically driven jets ejected from the collapsars, in which the magnetic fields before the collapse, are uniform and parallel to the rotational axis of the star and the magnitudes of the fields, B0, are 1010 G or 1012 G. We follow the evolution of chemical composition up to about 4000 nuclides inside the jets from the collapse phase to the ejection phase through the jet generation phase with use of a large nuclear reaction network. We find that the r-process successfully operates in the jets from the collapsar of B0 = 1012 G, so that U and Th are synthesized abundantly. Abundance pattern inside the jets is similar to that of r-elements in the solar system. Furthermore, we find that p-nuclei are produced without seed nuclei: not only light p-nuclei, such as 74Se, 78Kr, 84Sr, and 92Mo, but also heavy p-nuclei, 113In, 115Sn, and 138La, can be abundantly synthesized in the jets. The amounts of p-nuclei in the ejecta are much greater than those in core-collapse supernovae (SNe). In particular, 92Mo, 113In, 115Sn, and 138La deficient in the SNe, are significantly produced in the ejecta. On the other hand, in the jets from the collapsar of B0 = 1010 G, the r-process cannot operate and 56Ni, 28Si, 32S, and 4He are abundantly synthesized in the jets, as in ejecta from inner layers of Type II supernovae. An amount of 56Ni is much smaller than that from SN 1987A.

  7. Centrifugally driven electrostatic instability in extragalactic jets

    E-Print Network [OSTI]

    Z. Osmanov

    2008-01-29T23:59:59.000Z

    The stability problem of the rotation induced electrostatic wave in extragalactic jets is presented. Solving a set of equations describing dynamics of a relativistic plasma flow of AGN jets, an expression of the instability rate has been derived and analyzed for typical values of AGNs. The growth rate was studied versus the wave length and the inclination angle and it has been found that the instability process is much efficient with respect to the accretion disk evolution, indicating high efficiency of the instability.

  8. Stability Properties of Magnetic Tower Jets

    E-Print Network [OSTI]

    Masanori Nakamura; Hui Li; Shengtai Li

    2006-08-31T23:59:59.000Z

    Stability properties of ``magnetic tower'' jets propagating in the gravitationally stratified background have been examined by performing three-dimensional magnetohydrodynamic simulations. The current-carrying, Poynting flux-dominated magnetic tower jet, which possesses a highly wound helical magnetic field, is subject to the current-driven instability (CDI). We find that, under general physical conditions including small perturbations in the initial background profiles, the propagating magnetic tower jets develop the non-axisymmetric, $m=1$ kink mode of the CDI. The kink mode grows on the local Alfv\\'en crossing time scale. In addition, two types of kink modes appear in the system. At the central region where external thermal pressure confinement is strong, only the internal kink mode is excited and will grow. A large distance away from the central region where the external thermal pressure becomes low, the external kink mode is observed. As a result, the exterior of magnetic tower jets will be deformed into a large-scale wiggled structure. We also discuss extensively the different physical processes that contribute to the overall stability properties of the magnetic tower jets. Specifically, when the jet propagates in an initially unperturbed background, we find that they can survive the kink mode beyond the point predicted by the well-known Kruskal-Shafranov (K-S) criterion. The stabilization in this case comes mainly from the dynamical relaxation of magnetic twists during the propagation of magnetic towers; the magnetic pitch is reduced and the corresponding K-S critical wavelength becomes longer as the tower jet proceeds. Furthermore, we show that the pressure-driven and Kelvin-Helmholtz instabilities do not occur in the magnetic tower jets.

  9. Structure and Dynamics of Colliding Plasma Jets

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

    Li, C. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Ryutov, D. [Lawrence Livermore National Laboratory, Livermore, California; Hu, S. [Lab. for Laser Energetics, Univ. of Rochester, NY (United States); Rosenberg, M. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Zylstra, A. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Seguin, F. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Frenje, J. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Casey, D. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Gatu Johnson, M. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Manuel, M. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Rinderknecht, H. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Petrasso, R. [Massachusetts Institute of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Amendt, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Remington, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wilks, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betti, R. [Lab. for Laser Energetics, Univ. of Rochester, NY (United States); Froula, D. [Lab. for Laser Energetics, Univ. of Rochester, NY (United States); Knauer, J. [Lab. for Laser Energetics, Univ. of Rochester, NY (United States); Meyerhofer, D. [Lab. for Laser Energetics, Univ. of Rochester, NY (United States); Drake, R. [Univ. of Michigan, Ann Arbor, MI (United States); Kuranz, C. [Univ. of Michigan, Ann Arbor, MI (United States); Young, R. [Univ. of Michigan, Ann Arbor, MI (United States); Koenig, M. [Laboratoire pour l’Utilisation des Lasers Intenses, CNRS–CEA–Université Paris VI–Ecole Polytechnique (France)

    2013-12-01T23:59:59.000Z

    Monoenergetic-proton radiographs of laser-generated, high-Mach-number plasma jets colliding at various angles shed light on the structures and dynamics of these collisions. The observations compare favorably with results from 2D hydrodynamic simulations of multistream plasma jets, and also with results from an analytic treatment of electron flow and magnetic field advection. In collisions of two noncollinear jets, the observed flow structure is similar to the analytic model’s prediction of a characteristic feature with a narrow structure pointing in one direction and a much thicker one pointing in the opposite direction. Spontaneous magnetic fields, largely azimuthal around the colliding jets and generated by the well-known ?Te ×?ne Biermann battery effect near the periphery of the laser spots, are demonstrated to be “frozen in” the plasma (due to high magnetic Reynolds number RM ~5×10?) and advected along the jet streamlines of the electron flow. These studies provide novel insight into the interactions and dynamics of colliding plasma jets.

  10. Structure and Dynamics of Colliding Plasma Jets

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

    Li, C.; Ryutov, D.; Hu, S.; Rosenberg, M.; Zylstra, A.; Seguin, F.; Frenje, J.; Casey, D.; Gatu Johnson, M.; Manuel, M.; et al

    2013-12-01T23:59:59.000Z

    Monoenergetic-proton radiographs of laser-generated, high-Mach-number plasma jets colliding at various angles shed light on the structures and dynamics of these collisions. The observations compare favorably with results from 2D hydrodynamic simulations of multistream plasma jets, and also with results from an analytic treatment of electron flow and magnetic field advection. In collisions of two noncollinear jets, the observed flow structure is similar to the analytic model’s prediction of a characteristic feature with a narrow structure pointing in one direction and a much thicker one pointing in the opposite direction. Spontaneous magnetic fields, largely azimuthal around the colliding jets and generatedmore »by the well-known ?Te ×?ne Biermann battery effect near the periphery of the laser spots, are demonstrated to be “frozen in” the plasma (due to high magnetic Reynolds number RM ~5×10?) and advected along the jet streamlines of the electron flow. These studies provide novel insight into the interactions and dynamics of colliding plasma jets.« less

  11. Jet Production in p-Pb Collisions

    E-Print Network [OSTI]

    Megan Connors; for the ALICE Collaboration

    2014-09-19T23:59:59.000Z

    One of the major results from the study of high energy heavy ion collisions is the observation of jet quenching. The suppression of the number of jets observed in heavy ion collisions relative to pp collisions at the same energy scaled by the number of binary collisions, is attributed to partonic energy loss in the quark gluon plasma (QGP). However, cold nuclear matter effects due to the presence of a nucleus in the initial state could also influence this measurement. To disentangle these effects p-Pb collisions are studied, where QGP formation is not expected to occur and only cold nuclear matter effects are present. In addition to being an important baseline for understanding jet quenching, jets in p-Pb collisions may also be used to provide constraints on the nuclear parton distribution functions. Fully reconstructed jets measured using the ALICE tracking system and electro-magnetic calorimeter in p-Pb collisions at $\\sqrt{s_{NN}}=5.02$ TeV are reported. In addition to the spectra, studies of the jet fragmentation behavior in p-Pb collisions are also presented.

  12. Azimuthal Jet Tomography at RHIC and LHC

    E-Print Network [OSTI]

    Barbara Betz; Miklos Gyulassy

    2014-07-28T23:59:59.000Z

    Results based on a generic jet-energy loss model that interpolates between running coupling pQCD-based and AdS/CFT-inspired holographic prescriptions are compared to recent data on the high-p_T pion nuclear modification factor and the high-p_T elliptic flow in nuclear collisions at RHIC and LHC. The jet-energy loss model is coupled to various (2+1)d (viscous hydrodynamic) fields. The impact of energy-loss fluctuations is discussed. While a previously proposed AdS/CFT jet-energy loss model with a temperature-independent jet-medium coupling is shown to be inconsistent with the LHC data, we find a rather broad class of jet-energy independent energy-loss models $dE/dx= \\kappa(T) x^z T^{2+z}$ that can account for the current data with different temperature-dependent jet-medium couplings $\\kappa(T)$ and path-length dependence exponents of $0\\le z \\le 2$.

  13. On self-propulsion of $N$-sphere micro-robot

    E-Print Network [OSTI]

    Vladimir A. Vladimirov

    2012-09-02T23:59:59.000Z

    The aim of this paper is to describe the self-propulsion of a micro-robot (or micro-swimmer) consisting of $N$ spheres moving along a fixed line. The spheres are linked to each other by arms with the lengths changing periodically. For the derivation, we use the asymptotic procedure containing the two-timing method and a distinguished limit. We show that in the main approximation, the self-propulsion velocity appears as a linear combination of velocities of all possible triplets of spheres. Velocities and efficiencies of three-, four-, and five-swimmers are calculated. The paper is devoted to H.K.Moffatt, who initiated the author's interests in low-Reynolds-number fluid dynamics.

  14. Comparison of Space Propulsion Methods for a Manned Mission to Mars

    E-Print Network [OSTI]

    Guerra, A G C; Gil, P J S

    2015-01-01T23:59:59.000Z

    We undertake a comparison of the latest developments in propulsion technologies, for a manned mission to Mars. The main objective is to assess the possibility of reducing travel time keeping the mass at departure within bounds. For the sake of comparison we used representative systems of different state of the art or proposed technologies, from the chemical engine to the "Pure Electro-Magnetic Thrust" (PEMT) concept, using a nuclear engine proposed by Rubbia. A mission architecture is suggested, based on existing mission proposals to Mars, to estimate the mass budget that influences the performance of the propulsion system. The trajectory of the spacecraft is determined by a numerical integration of the equations of motion and a partial optimization procedure, for the interplanetary phase with continuous thrust, and by conics and instant manoeuvres in the regions of influence of the departure and arrival planets. Pareto curves of the duration of the mission and time of flight versus mass of mission are drawn....

  15. Cryochemical and CVD processing of shperical carbide fuels for propulsion reactors

    SciTech Connect (OSTI)

    Blair, H.T.; Carroll, D.W.; Matthews, R.B. (Los Alamos National Laboratory, MS E505, Los Alamos, New Mexico (USA))

    1991-01-10T23:59:59.000Z

    Many of the nuclear propulsion reactor concepts proposed for a manned mission to Mars use a coated spherical particle fuel form similar to that used in the Rover and NERVA propulsion reactors. The formation of uranium dicarbide microspheres using a cryochemical process and the coating of the UC{sub 2} spheres with zirconium carbide using chemical vapor deposition are being developed at Los Alamos National Laboratory. The cryochemical process is described with a discussion of the variables affecting the sphere formation and carbothermic reduction to produce UC{sub 2} spheres from UO{sub 2}. Emphasis is placed on minimizing the wastes produced by the process. The ability to coat particles with ZrC was recaptured, and improvements in the process and equipment were developed. Volatile organometallic precursors were investigated as alternatives to the original ZrCl{sub 4} precursor.

  16. Current Development of Nuclear Thermal Propulsion technologies at the Center for Space Nuclear Research

    SciTech Connect (OSTI)

    Robert C. O'Brien; Steven K. Cook; Nathan D. Jerred; Steven D. Howe; Ronald Samborsky; Daniel Brasuell

    2012-09-01T23:59:59.000Z

    Nuclear power and propulsion has been considered for space applications since the 1950s. Between 1955 and 1972 the US built and tested over twenty nuclear reactors / rocket engines in the Rover/NERVA programs1. The Aerojet Corporation was the prime contractor for the NERVA program. Modern changes in environmental laws present challenges for the redevelopment of the nuclear rocket. Recent advances in fuel fabrication and testing options indicate that a nuclear rocket with a fuel composition that is significantly different from those of the NERVA project can be engineered; this may be needed to ensure public support and compliance with safety requirements. The Center for Space Nuclear Research (CSNR) is pursuing a number of technologies, modeling and testing processes to further the development of safe, practical and affordable nuclear thermal propulsion systems.

  17. Research, development, and demonstration of nickel-iron batteries for electric vehicle propulsion. Annual report, 1980

    SciTech Connect (OSTI)

    Not Available

    1981-03-01T23:59:59.000Z

    The objective of the Eagle-Picher nickel-iron battery program is to develop a nickel-iron battery for use in the propulsion of electric and electric-hybrid vehicles. To date, the program has concentrated on the characterization, fabrication and testing of the required electrodes, the fabrication and testing of full-scale cells, and finally, the fabrication and testing of full-scale (270 AH) six (6) volt modules. Electrodes of the final configuration have now exceeded 1880 cycles and are showing minimal capacity decline. Full-scale cells have presently exceeded 600 cycles and are tracking the individual electrode tests almost identically. Six volt module tests have exceeded 500 cycles, with a specific energy of 48 Wh/kg. Results to date indicate the nickel-iron battery is beginning to demonstrate the performance required for electric vehicle propulsion.

  18. Mars Mission Analysis Trades Based on Legacy and Future Nuclear Propulsion Options

    SciTech Connect (OSTI)

    Joyner, Russell [Pratt and Whitney Rocketdyne, West Palm Beach, Florida (United States); Lentati, Andrea [Georgia Institute of Technology, Atlanta, Georgia (United States); Cichon, Jaclyn [University of Florida, Gainesville, Florida (United States)

    2007-01-30T23:59:59.000Z

    The purpose of this paper is to discuss the results of mission-based system trades when using a nuclear thermal propulsion (NTP) system for Solar System exploration. The results are based on comparing reactor designs that use a ceramic-metallic (CERMET), graphite matrix, graphite composite matrix, or carbide matrix fuel element designs. The composite graphite matrix and CERMET designs have been examined for providing power as well as propulsion. Approaches to the design of the NTP to be discussed will include an examination of graphite, composite, carbide, and CERMET core designs and the attributes of each in regards to performance and power generation capability. The focus is on NTP approaches based on tested fuel materials within a prismatic fuel form per the Argonne National Laboratory testing and the ROVER/NERVA program. NTP concepts have been examined for several years at Pratt and Whitney Rocketdyne for use as the primary propulsion for human missions beyond earth. Recently, an approach was taken to examine the design trades between specific NTP concepts; NERVA-based (UC)C-Graphite, (UC,ZrC)C-Composite, (U,Zr)C-Solid Carbide and UO2-W CERMET. Using Pratt and Whitney Rocketdyne's multidisciplinary design analysis capability, a detailed mission and vehicle model has been used to examine how several of these NTP designs impact a human Mars mission. Trends for the propulsion system mass as a function of power level (i.e. thrust size) for the graphite-carbide and CERMET designs were established and correlated against data created over the past forty years. These were used for the mission trade study. The resulting mission trades presented in this paper used a comprehensive modeling approach that captures the mission, vehicle subsystems, and NTP sizing.

  19. Recapturing Graphite-Based Fuel Element Technology for Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    Trammell, Michael P [ORNL; Jolly, Brian C [ORNL; Miller, James Henry [ORNL; Qualls, A L [ORNL; Harrison, Thomas J [ORNL

    2013-01-01T23:59:59.000Z

    ORNL is currently recapturing graphite based fuel forms for Nuclear Thermal Propulsion (NTP). This effort involves research and development on materials selection, extrusion, and coating processes to produce fuel elements representative of historical ROVER and NERVA fuel. Initially, lab scale specimens were fabricated using surrogate oxides to develop processing parameters that could be applied to full length NTP fuel elements. Progress toward understanding the effect of these processing parameters on surrogate fuel microstructure is presented.

  20. Heavy vehicle propulsion system materials program semiannual progress report for April 1999 through September 1999

    SciTech Connect (OSTI)

    Johnson, D.R.

    2000-01-01T23:59:59.000Z

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks.

  1. Dark Matter Searches with a Mono-Z' jet

    E-Print Network [OSTI]

    Yang Bai; James Bourbeau; Tongyan Lin

    2015-04-06T23:59:59.000Z

    We study collider signatures of a class of dark matter models with a GeV-scale dark Z'. At hadron colliders, the production of dark matter particles naturally leads to associated production of the Z', which can appear as a narrow jet after it decays hadronically. Contrary to the usual mono-jet signal from initial state radiation, the final state radiation of dark matter can generate the signature of a mono-Z' jet plus missing transverse energy. Performing a jet-substructure analysis to tag the Z' jet, we show that these Z' jets can be distinguished from QCD jets at high significance. Compared to mono-jets, a dedicated search for mono-Z' jet events can lead to over an order of magnitude stronger bounds on the interpreted dark matter-nucleon scattering cross sections.

  2. An Overview of Facilities and Capabilities to Support the Development of Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    James Werner; Sam Bhattacharyya; Mike Houts

    2011-02-01T23:59:59.000Z

    Abstract. The future of American space exploration depends on the ability to rapidly and economically access locations of interest throughout the solar system. There is a large body of work (both in the US and the Former Soviet Union) that show that Nuclear Thermal Propulsion (NTP) is the most technically mature, advanced propulsion system that can enable this rapid and economical access by its ability to provide a step increase above what is a feasible using a traditional chemical rocket system. For an NTP system to be deployed, the earlier measurements and recent predictions of the performance of the fuel and the reactor system need to be confirmed experimentally prior to launch. Major fuel and reactor system issues to be addressed include fuel performance at temperature, hydrogen compatibility, fission product retention, and restart capability. The prime issue to be addressed for reactor system performance testing involves finding an affordable and environmentally acceptable method to test a range of engine sizes using a combination of nuclear and non-nuclear test facilities. This paper provides an assessment of some of the capabilities and facilities that are available or will be needed to develop and test the nuclear fuel, and reactor components. It will also address briefly options to take advantage of the greatly improvement in computation/simulation and materials processing capabilities that would contribute to making the development of an NTP system more affordable. Keywords: Nuclear Thermal Propulsion (NTP), Fuel fabrication, nuclear testing, test facilities.

  3. Fluid-Induced Propulsion of Rigid Particles in Wormlike Micellar Solutions

    E-Print Network [OSTI]

    David A. Gagnon; Nathan C. Keim; Xiaoning Shen; Paulo E. Arratia

    2014-09-13T23:59:59.000Z

    In the absence of inertia, a reciprocal swimmer achieves no net motion in a viscous Newtonian fluid. Here, we investigate the ability of a reciprocally actuated particle to translate through a complex fluid that possesses a network using tracking methods and birefringence imaging. A geometrically polar particle, a rod with a bead on one end, is reciprocally rotated using magnetic fields. The particle is immersed in a wormlike micellar (WLM) solution that is known to be susceptible to the formation of shear bands and other localized structures due to shear-induced remodeling of its microstructure. Results show that the nonlinearities present in this WLM solution break time-reversal symmetry under certain conditions, and enable propulsion of an artificial "swimmer." We find three regimes dependent on the Deborah number (De): net motion towards the bead-end of the particle at low De, net motion towards the rod-end of the particle at intermediate De, and no appreciable propulsion at high De. At low De, where the particle time-scale is longer then the fluid relaxation time, we believe that propulsion is caused by an imbalance in the fluid first normal stress differences between the two ends of the particle (bead and rod). At De~1, however, we observe the emergence of a region of network anisotropy near the rod using birefringence imaging. This anisotropy suggests alignment of the micellar network, which is "locked in" due to the shorter time-scale of the particle relative to the fluid.

  4. The rationale/benefits of nuclear thermal rocket propulsion for NASA's lunar space transportation system

    SciTech Connect (OSTI)

    Borowski, S.K.

    1994-09-01T23:59:59.000Z

    The solid core nuclear thermal rocket (NTR) represents the next major evolutionary step in propulsion technology. With its attractive operating characteristics, which include high specific impulse (approximately 850-1000 s) and engine thrust-to-weight (approximately 4-20), the NTR can form the basis for an efficient lunar space transportation system (LTS) capable of supporting both piloted and cargo missions. Studies conducted at the NASA Lewis Research Center indicate that an NTR-based LTS could transport a fully-fueled, cargo-laden, lunar excursion vehicle to the Moon, and return it to low Earth orbit (LEO) after mission completion, for less initial mass in LEO than an aerobraked chemical system of the type studied by NASA during its '90-Day Study.' The all-propulsive NTR-powered LTS would also be 'fully reusable' and would have a 'return payload' mass fraction of approximately 23 percent--twice that of the 'partially reusable' aerobraked chemical system. Two NTR technology options are examined--one derived from the graphite-moderated reactor concept developed by NASA and the AEC under the Rover/NERVA (Nuclear Engine for Rocket Vehicle Application) programs, and a second concept, the Particle Bed Reactor (PBR). The paper also summarizes NASA's lunar outpost scenario, compares relative performance provided by different LTS concepts, and discusses important operational issues (e.g., reusability, engine 'end-of life' disposal, etc.) associated with using this important propulsion technology.

  5. Particle multiplicity of unbiased gluon jets from $e^+ e^-$ three-jet events

    E-Print Network [OSTI]

    Abbiendi, G; Ĺkesson, P F; Alexander, Gideon; Allison, J; Anagnostou, G; Anderson, K J; Arcelli, S; Asai, S; Axen, D A; Azuelos, Georges; Bailey, I; Barberio, E; Barlow, R J; Batley, J Richard; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, Siegfried; Biebel, O; Bloodworth, Ian J; Boeriu, O; Bock, P; Böhme, J; Bonacorsi, D; Boutemeur, M; Braibant, S; Brigliadori, L; Brown, R M; Burckhart, H J; Cammin, J; Campana, S; Carnegie, R K; Caron, B; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Clarke, P E L; Clay, E; Cohen, I; Couchman, J; Csilling, Akos; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; de Roeck, A; De Wolf, E A; Dervan, P J; Desch, Klaus; Dienes, B; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, Franco Luigi; Feld, L; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Günther, P O; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harder, K; Harel, A; Harin-Dirac, M; Hauschild, M; Hauschildt, J; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Hensel, C; Herten, G; Heuer, R D; Hill, J C; Hoffman, K; Homer, R James; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Ishii, K; Jawahery, A; Jeremie, H; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klein, K; Klier, A; Kluth, S; Kobayashi, T; Kobel, M; Kokott, T P; Komamiya, S; Kowalewski, R V; Kramer, T; Kress, T; Krieger, P; Von Krogh, J; Krop, D; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lawson, I; Layter, J G; Leins, A; Lellouch, Daniel; Letts, J; Levinson, L; Lillich, J; Littlewood, C; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Masetti, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Menges, W; Merritt, F S; Mes, H; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Moed, S; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oh, A; Okpara, A N; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Patrick, G N; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Pooth, O; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Rick, Hartmut; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rozen, Y; Runge, K; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Spanó, F; Sproston, M; Stahl, A; Stephens, K; Strom, D; Ströhmer, R; Stumpf, L; Surrow, B; Tarem, S; Tasevsky, M; Taylor, R J; Teuscher, R; Thomas, J; Thomson, M A; Torrence, E; Toya, D; Trefzger, T M; Tricoli, A; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vachon, B; Vollmer, C F; Vannerem, P; Verzocchi, M; Voss, H; Vossebeld, Joost Herman; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D; 10.1007/s100520200926

    2002-01-01T23:59:59.000Z

    The charged particle multiplicities of two- and three-jet events from the reaction e+e- -> Z0 -> hadrons are measured for Z0 decays to light quark (uds) flavors. Using recent theoretical expressions to account for biases from event selection, results corresponding to unbiased gluon jets are extracted over a range of jet energies from about 11 to 30 GeV. We find consistency between these results and direct measurements of unbiased gluon jet multiplicity from upsilon and Z0 decays. The unbiased gluon jet data including the direct measurements are compared to corresponding results for quark jets. We perform fits based on analytic expressions for particle multiplicity in jets to determine the ratio r = Ng/Nq of multiplicities between gluon and quark jets as a function of energy. We also determine the ratio of slopes, r(1) = (dNg/dy)/(dNq/dy), and of curvatures, r(2) = (d2Ng/dy2)/(d2Nq/dy2), where y specifies the energy scale. At 30 GeV, we find r = 1.422 +/- 0.051, r(1) = 1.761 +/- 0.071 and r(2) = 1.98 +/- 0.13,...

  6. Sound Waves from Quenched Jets

    E-Print Network [OSTI]

    Vladimir Khachatryan; Edward Shuryak

    2011-08-15T23:59:59.000Z

    Heavy ion collisions at RHIC/LHC energies are well described by the (nearly ideal) hydrodynamics. Last year this success has been extended to higher angular harmonics, $v_n,n=3..9$ induced by initial-state perturbations, in analogy to cosmic microwave background fluctuations. Here we use hydrodynamics to study sound propagation emitted by quenched jets. We use the so called "geometric acoustics" to follow the sound propagation, on top of the expanding fireball. The conical waves, known as "Mach cones", turn out to be strongly distorted. We show that large radial flow makes the observed particle spectra to be determined mostlly by the vicinity of their intersection with the fireball's space-like and time-like freezeout surfaces. We further show how the waves modify the freezeout surfaces and spectra. We end up comparing our calculations to the two-particle correlation functions at RHIC, while emphasizing that studies of dijet events observed at LHC should provide much better test of our theory.

  7. PHOTOSPHERIC EMISSION FROM STRATIFIED JETS

    SciTech Connect (OSTI)

    Ito, Hirotaka; Nagataki, Shigehiro; Ono, Masaomi; Lee, Shiu-Hang; Mao, Jirong [Astrophysical Big Bang Laboratory, RIKEN, Saitama 351-0198 (Japan); Yamada, Shoichi [Department of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Pe'er, Asaf [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mizuta, Akira [KEK Theory Center, Tsukuba 305-0801 (Japan); Harikae, Seiji, E-mail: hito@yukawa.kyoto-u.ac.jp [Quants Research Department, Financial Engineering Division, Mitsubishi UFJ Morgan Stanley Securities Co., Ltd., Mejirodai Bldg., 3-29-20 Mejirodai, Bunkyo-ku, Tokyo 112-8688 (Japan)

    2013-11-01T23:59:59.000Z

    We explore photospheric emissions from stratified two-component jets, wherein a highly relativistic spine outflow is surrounded by a wider and less relativistic sheath outflow. Thermal photons are injected in regions of high optical depth and propagated until the photons escape at the photosphere. Because of the presence of shear in velocity (Lorentz factor) at the boundary of the spine and sheath region, a fraction of the injected photons are accelerated using a Fermi-like acceleration mechanism such that a high-energy power-law tail is formed in the resultant spectrum. We show, in particular, that if a velocity shear with a considerable variance in the bulk Lorentz factor is present, the high-energy part of observed gamma-ray bursts (GRBs) photon spectrum can be explained by this photon acceleration mechanism. We also show that the accelerated photons might also account for the origin of the extra-hard power-law component above the bump of the thermal-like peak seen in some peculiar bursts (e.g., GRB 090510, 090902B, 090926A). We demonstrate that time-integrated spectra can also reproduce the low-energy spectrum of GRBs consistently using a multi-temperature effect when time evolution of the outflow is considered. Last, we show that the empirical E{sub p}-L{sub p} relation can be explained by differences in the outflow properties of individual sources.

  8. MULTIWAVELENGTH OBSERVATIONS OF THE SS 433 JETS

    SciTech Connect (OSTI)

    Marshall, Herman L.; Canizares, Claude R.; Schulz, Norbert S.; Nowak, Michael [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Hillwig, Todd [Department of Physics and Astronomy, Valparaiso University, Valparaiso, IN 46383 (United States); Mioduszewski, Amy; Rupen, Michael [NRAO, P.O. Box 2, Socorro, NM 87801 (United States); Heinz, Sebastian, E-mail: hermanm@space.mit.edu, E-mail: crc@space.mit.edu, E-mail: nss@space.mit.edu, E-mail: mnowak@space.mit.edu, E-mail: todd.hillwig@valpo.edu, E-mail: amiodusz@nrao.edu, E-mail: mrupen@aoc.nrao.edu, E-mail: heinzs@astro.wisc.edu [Astronomy Department, 5408 Sterling Hall, University of Wisconsin, Madison, WI 53706 (United States)

    2013-09-20T23:59:59.000Z

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 10{sup 14} cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to ?> 2 × 10{sup 12} cm. The base jet density is in the range 10{sup 10-13} cm{sup –3}, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  9. Small Fast Spectrum Reactor Designs Suitable for Direct Nuclear Thermal Propulsion

    SciTech Connect (OSTI)

    Bruce G. Schnitzler; Stanley K. Borowski

    2012-07-01T23:59:59.000Z

    Advancement of U.S. scientific, security, and economic interests through a robust space exploration program requires high performance propulsion systems to support a variety of robotic and crewed missions beyond low Earth orbit. Past studies, in particular those in support of both the Strategic Defense Initiative (SDI) and Space Exploration Initiative (SEI), have shown nuclear thermal propulsion systems provide superior performance for high mass high propulsive delta-V missions. The recent NASA Design Reference Architecture (DRA) 5.0 Study re-examined mission, payload, and transportation system requirements for a human Mars landing mission in the post-2030 timeframe. Nuclear thermal propulsion was again identified as the preferred in-space transportation system. A common nuclear thermal propulsion stage with three 25,000-lbf thrust engines was used for all primary mission maneuvers. Moderately lower thrust engines may also have important roles. In particular, lower thrust engine designs demonstrating the critical technologies that are directly extensible to other thrust levels are attractive from a ground testing perspective. An extensive nuclear thermal rocket technology development effort was conducted from 1955-1973 under the Rover/NERVA Program. Both graphite and refractory metal alloy fuel types were pursued. Reactors and engines employing graphite based fuels were designed, built and ground tested. A number of fast spectrum reactor and engine designs employing refractory metal alloy fuel types were proposed and designed, but none were built. The Small Nuclear Rocket Engine (SNRE) was the last engine design studied by the Los Alamos National Laboratory during the program. At the time, this engine was a state-of-the-art graphite based fuel design incorporating lessons learned from the very successful technology development program. The SNRE was a nominal 16,000-lbf thrust engine originally intended for unmanned applications with relatively short engine operations and the engine and stage design were constrained to fit within the payload volume of the then planned space shuttle. The SNRE core design utilized hexagonal fuel elements and hexagonal structural support elements. The total number of elements can be varied to achieve engine designs of higher or lower thrust levels. Some variation in the ratio of fuel elements to structural elements is also possible. Options for SNRE-based engine designs in the 25,000-lbf thrust range were described in a recent (2010) Joint Propulsion Conference paper. The reported designs met or exceeded the performance characteristics baselined in the DRA 5.0 Study. Lower thrust SNRE-based designs were also described in a recent (2011) Joint Propulsion Conference paper. Recent activities have included parallel evaluation and design efforts on fast spectrum engines employing refractory metal alloy fuels. These efforts include evaluation of both heritage designs from the Argonne National Laboratory (ANL) and General Electric Company GE-710 Programs as well as more recent designs. Results are presented for a number of not-yet optimized fast spectrum engine options.

  10. ON THE STRUCTURE AND STABILITY OF MAGNETIC TOWER JETS

    SciTech Connect (OSTI)

    Huarte-Espinosa, M.; Frank, A.; Blackman, E. G. [Department of Physics and Astronomy, University of Rochester, 600 Wilson Boulevard, Rochester, NY 14627-0171 (United States); Ciardi, A. [LERMA, Universite Pierre et Marie Curie, Observatoire de Paris, F-92195 Meudon (France); Hartigan, P. [Department of Physics and Astronomy, Rice University, 6100 S. Main, Houston, TX 77521-1892 (United States); Lebedev, S. V.; Chittenden, J. P. [Blackett Laboratory, Imperial College London, SW7 2BW London (United Kingdom)

    2012-09-20T23:59:59.000Z

    Modern theoretical models of astrophysical jets combine accretion, rotation, and magnetic fields to launch and collimate supersonic flows from a central source. Near the source, magnetic field strengths must be large enough to collimate the jet requiring that the Poynting flux exceeds the kinetic energy flux. The extent to which the Poynting flux dominates kinetic energy flux at large distances from the engine distinguishes two classes of models. In magneto-centrifugal launch models, magnetic fields dominate only at scales {approx}< 100 engine radii, after which the jets become hydrodynamically dominated (HD). By contrast, in Poynting flux dominated (PFD) magnetic tower models, the field dominates even out to much larger scales. To compare the large distance propagation differences of these two paradigms, we perform three-dimensional ideal magnetohydrodynamic adaptive mesh refinement simulations of both HD and PFD stellar jets formed via the same energy flux. We also compare how thermal energy losses and rotation of the jet base affects the stability in these jets. For the conditions described, we show that PFD and HD exhibit observationally distinguishable features: PFD jets are lighter, slower, and less stable than HD jets. Unlike HD jets, PFD jets develop current-driven instabilities that are exacerbated as cooling and rotation increase, resulting in jets that are clumpier than those in the HD limit. Our PFD jet simulations also resemble the magnetic towers that have been recently created in laboratory astrophysical jet experiments.

  11. Control of the microclimate around the head with opposing jet local ventilation

    E-Print Network [OSTI]

    Liu, Chonghui; Higuchi, Hiroshi; Arens, Edward; Zhang, Hui Ph.D

    2009-01-01T23:59:59.000Z

    of opposing jet local ventilation. AIAA 2009 Region I-NEHead with Opposing Jet Local Ventilation Chonghui Liu 1,* ,

  12. Elucidating Jet Energy Loss in Heavy Ion Collisions

    E-Print Network [OSTI]

    N. Grau; for the ATLAS Collaboration

    2008-11-05T23:59:59.000Z

    Very soon the LHC will provide beams for heavy ion collisions at 5.52 TeV/nucleon. This center-of-mass energy results in a large cross-section for producing high-$E_T$ ($>$ 50 GeV) jets that are distinct from the soft, underlying event. This brings with it the possibility of performing full jet reconstruction to directly study jet energy loss in the medium produced in heavy ion collisions. In this note, we present the current state of jet reconstruction performance studies in heavy ion events using the ATLAS detector. We also discuss the possibilities of energy loss measurements available with full jet reconstruction: single jet $R_{AA}$ and di-jet and $\\gamma$-jet correlations.

  13. Feedback control of flow separation using synthetic jets

    E-Print Network [OSTI]

    Kim, Kihwan

    2006-04-12T23:59:59.000Z

    The primary goal of this research is to assess the effect of synthetic jets on flow separation and provide a feedback control strategy for flow separation using synthetic jets. The feedback control synthesis is conducted based upon CFD simulation...

  14. Jet Areas, and What They are Good For

    E-Print Network [OSTI]

    Matteo Cacciari

    2007-06-19T23:59:59.000Z

    We introduce the concept of the area of a jet, and show how it can be used to perform the subtraction of even a large amount of diffuse noise from hard jets.

  15. Images in Emergency Medicine: Irritant Contact Dermatitis from Jet Fuel

    E-Print Network [OSTI]

    Trigger, Christopher C; Eilbert, Wesley

    2009-01-01T23:59:59.000Z

    and penetration of JP-8 jet fuel and its components. Toxicoland other kerosene-based fuels have been shown to cause skinContact Dermatitis from Jet Fuel Christopher C. Trigger, MD

  16. Active noise control of supersonic impinging jet using pulsed microjets

    E-Print Network [OSTI]

    Hong, Seung Hyuck

    2009-01-01T23:59:59.000Z

    This thesis concerns an active noise control of supersonic impinging jet flow using unsteady microjet injection. Supersonic impinging jet involves several problems such as lift loss, ground erosion, significant noise ...

  17. Extragalactic jets on subpc and large scales

    E-Print Network [OSTI]

    F. Tavecchio

    2007-08-20T23:59:59.000Z

    Jets can be probed in their innermost regions (d~0.1 pc) through the study of the relativistically-boosted emission of blazars. On the other extreme of spatial scales, the study of structure and dynamics of extragalactic relativistic jets received renewed impulse after the discovery, made by Chandra, of bright X-ray emission from regions at distances larger than hundreds of kpc from the central engine. At both scales it is thus possible to infer some of the basic parameters of the flow (speed, density, magnetic field intensity, power). After a brief review of the available observational evidence, I discuss how the comparison between the physical quantities independently derived at the two scales can be used to shed light on the global dynamics of the jet, from the innermost regions to the hundreds of kpc scale.

  18. Jet Structure in Heavy Ion Collisions

    E-Print Network [OSTI]

    Jean-Paul Blaizot; Yacine Mehtar-Tani

    2015-03-19T23:59:59.000Z

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter $\\hat q $. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

  19. On the Misalignment of Jets in Microquasars

    E-Print Network [OSTI]

    Thomas J. Maccarone

    2002-09-05T23:59:59.000Z

    We discuss the timescales for alignment of black hole and accretion disc spins in the context of binary systems. We show that for black holes that are formed with substantial angular momentum, the alignment timescales are likely to be at least a substantial fraction of the systems' lifetimes. This result explains the observed misalignment of the disc and the jet in the microquasar GRO J 1655-40 and in SAX J 1819-2525 as being likely due to the Bardeen-Petterson effect. We discuss the implications of these results on the mass estimate for GRS 1915+105, which has assumed the jet is perpendicular to the orbital plane of the system and may hence be an underestimate. We show that the timescales for the spin alignment in Cygnus X-3 are consistent with the likely misalignment of disc and jet in that system, and that this is suggested by the observational data.

  20. Stability of a jet in crossflow

    E-Print Network [OSTI]

    Ilak, Miloš; Bagheri, Shervin; Chevalier, Mattias; Henningson, Dan S

    2010-01-01T23:59:59.000Z

    We have produced a fluid dynamics video with data from Direct Numerical Simulation (DNS) of a jet in crossflow at several low values of the velocity inflow ratio R. We show that, as the velocity ratio R increases, the flow evolves from simple periodic vortex shedding (a limit cycle) to more complicated quasi-periodic behavior, before finally exhibiting asymmetric chaotic motion. We also perform a stability analysis just above the first bifurcation, where R is the bifurcation parameter. Using the overlap of the direct and the adjoint eigenmodes, we confirm that the first instability arises in the shear layer downstream of the jet orifice on the boundary of the backflow region just behind the jet.

  1. Jet Structure in Heavy Ion Collisions

    E-Print Network [OSTI]

    Blaizot, Jean-Paul

    2015-01-01T23:59:59.000Z

    We review recent theoretical developments in the study of the structure of jets that are produced in ultra relativistic heavy ion collisions. The core of the review focusses on the dynamics of the parton cascade that is induced by the interactions of a fast parton crossing a quark-gluon plasma. We recall the basic mechanisms responsible for medium induced radiation, underline the rapid disappearance of coherence effects, and the ensuing probabilistic nature of the medium induced cascade. We discuss how large radiative corrections modify the classical picture of the gluon cascade, and how these can be absorbed in a renormalization of the jet quenching parameter $\\hat q $. Then, we analyze the (wave)-turbulent transport of energy along the medium induced cascade, and point out the main characteristics of the angular structure of such a cascade. Finally, color decoherence of the in-cone jet structure is discussed. Modest contact with phenomenology is presented towards the end of the review.

  2. Formation of relativistic jets by collapsing stars to black holes

    E-Print Network [OSTI]

    V. Kryvdyk

    2007-03-12T23:59:59.000Z

    Formation of relativistic jets in the magnetosphere of collapsing stars is considered. These jets will be formed in the polar caps of magnetosphere of collapsing star, where the stellar magnetic field increases during the collapse and the charged particles are accelerated. The jets will generate non-thermal radiation. The analysis of dynamics and emission of particles in the stellar magnetosphere under collapse shows that collapsing stars can by powerful sources of relativistic jets.

  3. On the Counter-jet Emission in GRB Afterglows

    SciTech Connect (OSTI)

    Wang Xin; Huang, Y. F. [Department of Astronomy, Nanjing University, Nanjing 210093 (China)

    2010-10-15T23:59:59.000Z

    We investigate the dynamical evolution of double-sided jets and present detailed numerical studies on the emission from the receding jet of gamma-ray bursts. It is found that the receding jet emission is generally very weak and only manifests as a plateau in the late time radio afterglow light curves. Additionally, we find that the effect of synchrotron self-absorption can influence the peak time of the receding jet emission significantly.

  4. Gauge/gravity duality and jets in strongly coupled plasma

    E-Print Network [OSTI]

    Paul M. Chesler

    2009-10-08T23:59:59.000Z

    We discuss jets in strongly coupled N = 4 supersymmetric Yang-Mills plasma and their dual gravitational description.

  5. QCD Jet Rates with the Inclusive Generalized kt Algorithms

    E-Print Network [OSTI]

    Erik Gerwick; Ben Gripaios; Steffen Schumann; Bryan Webber

    2013-04-15T23:59:59.000Z

    We derive generating functions, valid to next-to-double logarithmic accuracy, for QCD jet rates according to the inclusive forms of the kt, Cambridge/Aachen and anti-kt algorithms, which are equivalent at this level of accuracy. We compare the analytical results with jet rates and average jet multiplicities from the SHERPA event generator, and study the transition between Poisson-like and staircase-like behaviour of jet ratios.

  6. High pressure water jet mining machine

    DOE Patents [OSTI]

    Barker, Clark R. (Rolla, MO)

    1981-05-05T23:59:59.000Z

    A high pressure water jet mining machine for the longwall mining of coal is described. The machine is generally in the shape of a plowshare and is advanced in the direction in which the coal is cut. The machine has mounted thereon a plurality of nozzle modules each containing a high pressure water jet nozzle disposed to oscillate in a particular plane. The nozzle modules are oriented to cut in vertical and horizontal planes on the leading edge of the machine and the coal so cut is cleaved off by the wedge-shaped body.

  7. Screening of Hydrocarbon Sources in JET

    SciTech Connect (OSTI)

    J.D. Strachan; W. Fundamenski; M. Charlet; K. Erents; J. Gafert; C. Giroud; M. von Hellermann; G. Matthews; G. McCracken; V. Philipps; J. Spence; M.F. Stamp; K-D. Zastrow; and EFDA-JET Work Programme Collaborators

    2001-06-15T23:59:59.000Z

    Carbon is the principal impurity in the Joint European Torus (JET). Methane screening experiments quantify the ability of the scrape-off layer (SOL)/divertor system to ionize carbon and transport it to the divertor, preventing core plasma contamination. Previous JET publications studied edge-localized-mode-averaged high-confinement mode screening, and separately, evaluated the methodology of low-confinement mode (L-mode) screening measurements. This paper extends the L-mode measurements to include relevant plasma parameter scans and DIVIMP modeling of the L-mode screening.

  8. THE HELICAL JET OF THE VELA PULSAR

    SciTech Connect (OSTI)

    Durant, Martin; Kargaltsev, Oleg [University of Florida, 211 Bryant Space Science Center, Gainesville, FL (United States)] [University of Florida, 211 Bryant Space Science Center, Gainesville, FL (United States); Pavlov, George G. [Pennsylvania State University, 525 Davey Lab, University Park, PA (United States)] [Pennsylvania State University, 525 Davey Lab, University Park, PA (United States); Kropotina, Julia; Levenfish, Kseniya, E-mail: mdurant@sri.utoronto.ca [St.-Petersburg State Polytechnical University, Polytekhnicheskaya ul. 29, St.-Petersburg, 195251 (Russian Federation)] [St.-Petersburg State Polytechnical University, Polytekhnicheskaya ul. 29, St.-Petersburg, 195251 (Russian Federation)

    2013-02-15T23:59:59.000Z

    We have studied the fascinating dynamics of the nearby Vela pulsar's nebula in a campaign comprising 11 40 ks observations with the Chandra X-Ray Observatory. The deepest images yet revealed the shape, structure, and motion of the 2 arcmin long pulsar jet. We find that the jet's shape and dynamics are remarkably consistent with those of a steadily turning helix projected on the sky. We discuss possible implications of our results, including free precession of the neutron star and MHD instability scenarios.

  9. Cascade impactor and jet plate for same

    DOE Patents [OSTI]

    Dahlin, Robert S.; Farthing, William E.; Landham Jr., Edward C.

    2004-02-03T23:59:59.000Z

    A sampling system and method for sampling particulate matter from a high-temperature, high-pressure gas stream. A cyclone sampler for use at high temperatures and pressures, and having threadless sacrificial connectors is disclosed. Also disclosed is an improved cascade impactor including jet plates with integral spacers, and alignment features provided for aligning the jet plates with their associated collection substrates. An activated bauxite alkali collector is disclosed, and includes an alumina liner. The sampling system can be operated remotely or locally, and can be permanently installed or configured as a portable system.

  10. Enhancement of wall jet transport properties

    DOE Patents [OSTI]

    Claunch, Scott D. (Broomfield, CO); Farrington, Robert B. (Golden, CO)

    1997-01-01T23:59:59.000Z

    By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct.

  11. Investigating jet quenching on the lattice

    E-Print Network [OSTI]

    Marco Panero; Kari Rummukainen; Andreas Schäfer

    2014-07-08T23:59:59.000Z

    Due to the dynamical, real-time, nature of the phenomenon, the study of jet quenching via lattice QCD simulations is not straightforward. In this contribution, however, we show how one can extract information about the momentum broadening of a hard parton moving in the quark-gluon plasma, from lattice calculations. After discussing the basic idea (originally proposed by Caron-Huot), we present a recent study, in which we estimated the jet quenching parameter non-perturbatively, from the lattice evaluation of a particular set of gauge-invariant operators.

  12. Gamma-Ray Bursts: Jets and Energetics

    E-Print Network [OSTI]

    D. A. Frail

    2003-11-12T23:59:59.000Z

    The relativistic outflows from gamma-ray bursts are now thought to be narrowly collimated into jets. After correcting for this jet geometry there is a remarkable constancy of both the energy radiated by the burst and the kinetic energy carried by the outflow. Gamma-ray bursts are still the most luminous explosions in the Universe, but they release energies that are comparable to supernovae. The diversity of cosmic explosions appears to be governed by the fraction of energy that is coupled to ultra-relativistic ejecta.

  13. Dense, vertical jet in stagnant homogeneous fluid

    E-Print Network [OSTI]

    Vergara, Ignacio

    1977-01-01T23:59:59.000Z

    ~ip t The laboratory equipment for the experiment consisted of a receiving tank, an auxiliary tank for the PreParation of the jet fluid and mixing of the dye, a pumping system, a concentration measurement system and photographic equip- ment. The receiving tank... of ejected brine = 1Os O/Tank capacity Jet or nozzle diamter Total water depth [in model is tank depth (l. 22 m)] Thickness of the dense layer a L the bottom Water depth at the nozzle F2 Fr Negative b Densimetri Accelerati (9. 8 m/sec xDz uoyancy...

  14. Enhancement of wall jet transport properties

    DOE Patents [OSTI]

    Claunch, S.D.; Farrington, R.B.

    1997-02-04T23:59:59.000Z

    By enhancing the natural instabilities in the boundary layer and in the free shear layer of a wall jet, the boundary is minimized thereby increasing the transport of heat and mass. Enhancing the natural instabilities is accomplished by pulsing the flow of air that creates the wall jet. Such pulsing of the flow of air can be accomplished by sequentially occluding and opening a duct that confines and directs the flow of air, such as by rotating a disk on an axis transverse to the flow of air in the duct. 17 figs.

  15. A study of the self-oscillating jet impingement nozzle

    E-Print Network [OSTI]

    Chinnock, Paul Scott

    1993-01-01T23:59:59.000Z

    In line jets are used throughout industry for drying and heat transfer. A simple modification to an in line jet offers significant enhancement of transport properties. The addition of a collar to an in line jet exit introduces an acoustic standing...

  16. MULTI-JET HIGGSSTRAHLUNG ANALYSIS MICHAEL T. RONAN

    E-Print Network [OSTI]

    MULTI-JET HIGGSSTRAHLUNG ANALYSIS MICHAEL T. RONAN LBNL, Berkeley, CA 94720, USA An analysis of multi-jet Higgsstrahlung signal and backgrounds is presented for events generated by Pandora, Pythia;orts are compared within a common Java framework. A preliminary result on the expected multi-jet Higgs

  17. POYNTING JETS FROM ACCRETION DISKS R. V. E. Lovelace,1

    E-Print Network [OSTI]

    for the understanding of the jets from active galactic nuclei, microquasars, and possibly gamma-ray burst sources by the electromagnetic field, which is relevant to extragalactic and microquasar jets and possibly to gamma-ray burst- sion-line jets are seen in young stellar objects (Mundt 1985; Bu¨ehrke, Mundt, & Ray 1988). Recent work

  18. Jet schemes of rational double point singularities Hussein MOURTADA

    E-Print Network [OSTI]

    Favre, Charles - Institut de Mathématiques de Jussieu, Université Paris 7

    Jet schemes of rational double point singularities Hussein MOURTADA April 9, 2013 Abstract We prove that for m N, m big enough, the number of irreducible components of the schemes of m-jets centered of the jet schemes of an E6 singularity to its "minimal" embedded resolutions of singularities. 1

  19. Jet schemes of rational double point singularities Hussein MOURTADA

    E-Print Network [OSTI]

    Jet schemes of rational double point singularities Hussein MOURTADA September 30, 2012 Abstract We prove that for m N, m big enough, the number of irreducble components of the schemes of m-jets centered of the jet schemes of an E6 singularity to its "minimal" embedded resolutions of singularities. 1

  20. Jet schemes of rational double point singularities Hussein Mourtada

    E-Print Network [OSTI]

    Bodin, Arnaud

    Jet schemes of rational double point singularities Hussein Mourtada Abstract. We prove that for m N, m big enough, the number of irreducible compo- nents of the schemes of m-jets centered at a point on the minimal reso- lution of the singularity. We also relate some irreducible components of the jet schemes

  1. Direct Numerical Simulations and Modeling of Jets in Crossflow

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies

  2. Simulations of High Speed Turbulent Jets in Crossflow Xiaochuan Chai

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Simulations of High Speed Turbulent Jets in Crossflow Xiaochuan Chai and Krishnan Mahesh-expanded sonic jet injected into a supersonic crossflow and an over-expanded supersonic jet injected into a subsonic crossflow. A finite volume compressible Navier­Stokes solver developed by Park & Mahesh (2007

  3. Simulations of High Speed Turbulent Jets in Crossflows Xiaochuan Chai

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Simulations of High Speed Turbulent Jets in Crossflows Xiaochuan Chai and Krishnan Mahesh-expanded sonic jet injected into a supersonic crossflow and an over-expanded supersonic jet injected into a subsonic crossflow, where the flow conditions are based on Santiago et al.'s (1997) and Beresh et al

  4. Studying Z/gamma*+Jet Production

    SciTech Connect (OSTI)

    Nilsen, Henrik Wold; /Freiburg U.

    2009-07-01T23:59:59.000Z

    The production of jets in association with a Z/{gamma}* boson is an example of an important class of processes at hadron colliders, namely vector boson + jet (V + jet) production. Comparisons of measurements of this class of processes with theory predictions constitute an important, fundamental test of the Standard Model of particle physics, and of the theory of QCD in particular. While having a smaller cross section than other V +jet processes, Z/{gamma}*({yields} e{sup +}e{sup -}) + jets production, with Z/{gamma}* {yields} e{sup +}e{sup -}/{mu}{sup +}{mu}{sup -}, has a distinct experimental signature allowing for measurements characterized by low backgrounds and a direct, precise measurement of the properties of the decay products of the Z/{gamma}* boson. In this thesis, several new measurements of the properties of jets produced in association with a Z/{gamma}* boson in p{bar p} collisions at {radical}s = 1.96 TeV are presented. The cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jet production (N {le} 3) is measured, differential in the transverse momentum of the Nth jet in the event, normalized to the inclusive Z/{gamma}* cross section. Also, the cross section for Z/{gamma}*({yields} e{sup +}e{sup -}) + N jets (N {ge} 1) is measured, differential in the difference in azimuthal angle between the di-electron system and any jet in the event, normalized to unity. The data used in the measurements were collected by the D0 experiment located at the Tevatron Collider of the Fermi National Accelerator Laboratory and correspond to an integrated luminosity of 1.04 fb{sup -1}. The measured jet transverse momentum spectra are compared with the predictions of perturbative calculations at the next-to-leading order in the strong coupling constant. Given the low sensitivity of the calculations to model parameters, these comparisons represent a stringent test of perturbative QCD. One of the main goals currently being pursued in particle physics is the discovery of the only particle predicted by the Standard Model which has so far no been detected experimentally, namely the Higgs boson. It is assumed that the ATLAS and CMS experiments located at the Large Hadron Collider (LHC), a proton-proton collider at {radical}s = 14 TeV, will be able to detect the Higgs boson, or rule out its existence, within the next few years. The collisions delivered by the LHC will also be used to perform a long range of searches for other new particles, for instance particles predicted by models based on the principle of supersymmetry. The associated production of vector bosons with jets has relatively large production rates at the LHC and can produce a long list of different final states which can include charged leptons, missing transverse energy, as well as light- and heavy-flavour jets. This makes V + jet production a major source of background events to many searches for new particles. Most techniques used for estimating the expected number of background events to searches rely on passing the stable final-state particles of simulated hadron collisions generated using a so-called event generator code, through a simulation of the experimental detector system. The development of event generators which are capable of reliably predicting the properties of jets produced in association with a core process, e.g. the production of a vector boson, has been the subject of a large amount of research activity during the last ten years. These efforts have led to the appearance of the CKKW and MLM algorithms which are implemented in several event generators, among them SHERPA and ALPGEN + PYTHIA. The large data sample collected by the D0 experiment during Run II offers an excellent opportunity for validating these new event generators against experimental measurements of V + jet production. As argued above, the Z/{gamma}*({yields} e{sup +}e{sup -}) + jets process offers the combination of a clean experimental signature and large production rates, making it the process of choice for these studies.

  5. Nuclear propulsion systems for orbit transfer based on the particle bed reactor

    SciTech Connect (OSTI)

    Powell, J.R.; Ludewig, H.; Horn, F.L.; Araj, K.; Benenati, R.; Lazareth, O.; Slovik, G.; Solon, M.; Tappe, W.; Belisle, J.

    1987-01-01T23:59:59.000Z

    The technology of nuclear direct propulsion orbit transfer systems based on the Particle Bed Reactor (PBR) is described. A 200 megawatt illustrative design is presented for LEO to GEO and other high ..delta..V missions. The PBR-NOTV can be used in a one-way mode with the shuttle or an expendable launch vehicle, e.g., the Titan 34D7, or as a two-way reusable space tug. In the one-way mode, payload capacity is almost three times greater than that of chemical OTV's. PBR technology status is described and development needs outlined.

  6. Space Nuclear Power and Propulsion - a basic Tool for the manned Exploration of the Solar System

    SciTech Connect (OSTI)

    Frischauf, Norbert; Hamilton, Booz Allen [ESA/ESTEC, Keplerlaan 1, P.O. Box 29, NL-2200 AG Noordwijk (Netherlands)

    2004-07-01T23:59:59.000Z

    Humanity has started to explore space more than 40 years ago. Numerous spacecraft have left the Earth in this endeavour, but while unmanned spacecraft were already sent out on missions, where they would eventually reach the outer limits of the Solar System, manned exploration has always been confined to the tiny bubble of the Earth's gravitational well, stretching out at maximum to our closest celestial companion - the Moon - during the era of the Apollo programme in the late 60's and early 70's. When mankind made its giant leap, the exploration of our cosmic neighbour was seen as the initial step for the manned exploration of the whole Solar System. Consequently ambitious research and development programmes were undertaken at that time to enable what seemed to be the next logical steps: the establishment of a permanent settled base on the Moon and the first manned mission to Mars in the 80's. Nuclear space power and propulsion played an important role in these entire future scenarios, hence ambitious development programmes were undertaken to make these technologies available. Unfortunately the 70's-paradigm shift in space policies did not only bring an end to the Apollo programme, but it also brought a complete halt to all of these technology programmes and confined the human presence in space to a tiny bubble including nothing more than the Earth's sphere and a mere shell of a few hundred kilometres of altitude, too small to even include the Moon. Today, after more than three decades, manned exploration of the Solar System has become an issue again and so are missions to Moon and Mars. However, studies and analyses show that all of these future plans are hampered by today's available propulsion systems and by the problematic of solar power generation at distances at and beyond of Mars, a problem, however, that can readily be solved by the utilisation of space nuclear reactors and propulsion systems. This paper intends to provide an overview on the various fission- and fusion-based Nuclear Power and Propulsion system concepts and tries to compare these systems' different working principles and technical implementations with each other. The overview and comparison will be complemented by a closer look at ongoing activities related to research and development in this area and by an outlook on what kind of systems might be employed to carry the first astronauts to Mars and beyond. (autho0008.

  7. Two-loop Jet-Function and Jet-Mass for Top Quarks

    E-Print Network [OSTI]

    Ambar Jain; Ignazio Scimemi; Iain W. Stewart

    2008-06-16T23:59:59.000Z

    We compute the two-loop heavy quark jet-function in the heavy quark limit. This is one of the key ingredients in next-to-next-to-leading order (NNLO) and next-to-next-to-leading-log order (NNLL) computations of the invariant mass distribution of top-jets at a future e+e- collider. The shape of the top invariant mass distribution is affected by large logs which we compute at NNLL order. Exploiting the non-abelian exponentiation theorem, a definition of the top jet-mass is given which is transitive and whose renormalization group evolution is determined by the cusp-anomalous dimension to all orders in perturbation theory. Relations of the jet-mass to the pole, MSbar, and 1S masses are presented at two-loop order.

  8. ZZ jet and Graviton jet at NLO QCD: recent applications using GOLEM methods

    SciTech Connect (OSTI)

    Karg, Stefan; /Aachen, Tech. Hochsch.; Binoth, Thomas; Gleisberg, Tanju; /SLAC; Kauer, Nikolas; /Royal Holloway, U. of London; Sanguinetti, Gregory; /Savoie U.; Kramer, Michael; /Aachen, Tech. Hochsch.; Li, Qiang; /PSI, Villigen; Zeppenfeld, Dieter; /Karlsruhe U., ITP

    2010-05-26T23:59:59.000Z

    In this talk we discuss recent progress concerning precise predictions for hadron colliders. We show results of two applications of tensor reduction using GOLEM methods: the next-to-leading order (NLO) corrections to pp {yields} ZZ + jet as an important background for Higgs particle and new physics searches at hadron colliders, and the NLO corrections to graviton plus jet hadroproduction, which is an important channel for graviton searches at the Tevatron and the LHC.

  9. Inclusive jet cross section measurement at D0

    E-Print Network [OSTI]

    M. Voutilainen

    2006-09-15T23:59:59.000Z

    We present a new preliminary measurement of the inclusive jet cross section in pp-bar collisions based on a integrated luminosity of about 0.8 fb-1. The data were acquired using the D0 detector between 2002 and 2005. Jets are reconstructed using an iterative cone algorithm with radius R_cone = 0.7. The inclusive jet cross section is presented as a function of transverse jet momentum and rapidity. Predictions from perturbative QCD in next-to-leading order, plus threshold corrections in 2-loop accuracy describe the shape in the transverse jet momentum.

  10. Jet Multiplicity in Top-Quark Pair Events at CMS

    E-Print Network [OSTI]

    A. Descroix for the CMS Collaboration

    2014-11-11T23:59:59.000Z

    The normalised differential top quark-antiquark production cross section is measured as a function of the jet multiplicity. Using a procedure to associate jets to decay products of the top quarks, the differential cross section of the ttbar production is determined as a function of the additional jet multiplicity. The fraction of events with no additional jets is measured as a function of the threshold required for the transverse momentum of the additional jet. The measurements are compared with predictions from perturbative quantum chromodynamics and no significant deviations are observed.

  11. Jet Analysis in Heavy Ion Collisions in CMS

    E-Print Network [OSTI]

    M. B. Tonjes; for the CMS collaboration

    2008-10-17T23:59:59.000Z

    At the Relativistic Heavy Ion Collider, jets have been a useful tool to probe the properties of the hot, dense matter created. At the Large Hadron Collider, collisions of Pb+Pb at $\\sqrt{s_{NN}}$ = 5.5 TeV will provide a large cross section of jets at high $E_T$ above the minimum bias heavy ion background. Simulations of the Compact Muon Solenoid (CMS) experiment's capability to measure jets in heavy ion collisions are presented. In particular, $\\gamma$-jet measurements can estimate the amount of energy lost by a jet interacting strongly with the medium, since the tagged photon passes through unaffected.

  12. Probing nuclear matter with jet conversions 

    E-Print Network [OSTI]

    Liu, W.; Fries, Rainer J.

    2008-01-01T23:59:59.000Z

    present some estimates for the rate of jet conversions in a consistent Fokker-Planck framework and their impact on future high-p(T) identified hadron measurements at RHIC and LHC. We also suggest some novel observables to test flavor effects....

  13. HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT

    SciTech Connect (OSTI)

    Russo, Matthew [Department of Physics, University of Toronto, 60 St. George Street, Toronto, ON M5S 1A7 (Canada); Thompson, Christopher [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

    2013-08-20T23:59:59.000Z

    We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.

  14. NLO Vector Boson Production With Light Jets

    SciTech Connect (OSTI)

    Bern, Z.; Diana, G.; Dixon, L.J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Hoeche, S.; Ita, H.; Kosower, D.A.; Maitre, D.; Ozeren, K.

    2012-02-15T23:59:59.000Z

    In this contribution we present recent progress in the computation of next-to-leading order (NLO) QCD corrections for the production of an electroweak vector boson in association with jets at hadron colliders. We focus on results obtained using the virtual matrix element library BlackHat in conjunction with SHERPA, focusing on results relevant to understanding the background to top production. The production of a vector boson in association with several jets at the Large Hadron Collider (LHC) is an important background for other Standard Model processes as well as new physics signals. In particular, the production of a W boson in association with many jets is an important background for processes involving one or more top quarks. Precise predictions for the backgrounds are crucial to measurement of top-quark processes. Vector boson production in association with multiple jets is also a very important background for many SUSY searches, as it mimics the signatures of many typical decay chains. Here we will discuss how polarization information can be used as an additional handle to differentiate top pair production from 'prompt' W-boson production. More generally, ratios of observables, for example for events containing a W boson versus those containing a Z boson, are expected to be better-behaved as many uncertainties cancel in such ratios. Precise calculation of ratios, along with measurement of one of the two processes in the ratio, can be used in data-driven techniques for estimating backgrounds.

  15. Multi Jet Production at High Q2

    E-Print Network [OSTI]

    Thomas Kluge

    2005-10-31T23:59:59.000Z

    Deep-inelastic $e^+p$ scattering data, taken with the H1 detector at HERA, are used to investigate jet production over a range of four-momentum transfers $150 < Q^2 < 15000 \\mathrm{GeV}^2$ and transverse jet energies $5 < E_T < 50 \\mathrm{GeV}$. The analysis is based on data corresponding to an integrated luminosity of $\\mathcal{L}_\\mathrm{int} = 65.4 \\mathrm{pb}^{-1}$ taken in the years 1999-2000 at a centre-of-mass energy $\\sqrt{s} \\approx 319 \\mathrm{GeV}$. Jets are defined by the inclusive $k_t$ algorithm in the Breit frame of reference. Dijet and trijet jet cross sections are measured with respect to the exchanged boson virtuality and in addition the ratio of the trijet to the dijet cross section $R_{3/2}$ is investigated. The results are compared to the predictions of perturbative QCD calculations in next-to-leading order in the strong coupling constant $\\alpha_s$. The value of $\\alpha_s(m_Z)$ determined from the study of $R_{3/2}$ is $\\alpha_s(m_Z) = 0.1175 \\pm 0.0017 (\\mathrm{stat.}) \\pm 0.0050 (\\mathrm{syst.}) ^{+0.0054}_{-0.0068} (\\mathrm{theo.})$.

  16. Jet Vetoes Interfering with H->WW

    E-Print Network [OSTI]

    Ian Moult; Iain W. Stewart

    2014-09-08T23:59:59.000Z

    Far off-shell Higgs production in $H \\rightarrow WW,ZZ$, is a particularly powerful probe of Higgs properties, allowing one to disentangle Higgs width and coupling information unavailable in on-shell rate measurements. These measurements require an understanding of the cross section in the far off-shell region in the presence of realistic experimental cuts. We analytically study the effect of a $p_T$ jet veto on far off-shell cross sections, including signal-background interference, by utilizing hard functions in the soft collinear effective theory that are differential in the decay products of the $W/Z$. Summing large logarithms of $\\sqrt{\\hat s}/p_T^{veto}$, we find that the jet veto induces a strong dependence on the partonic centre of mass energy, $\\sqrt{\\hat s}$, and modifies distributions in $\\sqrt{\\hat s}$ or $M_T$. The example of $gg\\rightarrow H \\rightarrow WW$ is used to demonstrate these effects at next to leading log order. We also discuss the importance of jet vetoes and jet binning for the recent program to extract Higgs couplings and widths from far off-shell cross sections.

  17. AGN Jet Mass Loading and Truncation by Stellar Winds

    E-Print Network [OSTI]

    Alexander Hubbard; Eric G. Blackman

    2006-04-28T23:59:59.000Z

    Active Galactic Nuclei can produce extremely powerful jets. While tightly collimated, the scale of these jets and the stellar density at galactic centers implies that there will be many jet/star interactions, which can mass-load the jet through stellar winds. Previous work employed modest wind mass outflow rates, but this does not apply when mass loading is provided by a small number of high mass-loss stars. We construct a framework for jet mass-loading by stellar winds for a broader spectrum of wind mass-loss rates than has been previously considered. Given the observed stellar mass distributions in galactic centers, we find that even highly efficient (0.1 Eddington luminosity) jets from supermassive black holes of masses $M_{BH} \\la 10^4M_{\\odot}$ are rapidly mass loaded and quenched by stellar winds. For $10^4 M_{\\odot}jets is independent of the jet's mechanical luminosity. Stellar wind mass-loading is unable to quench efficient jets from more massive engines, but can account for the observed truncation of the inefficient M87 jet, and implies a baryon dominated composition on scales $\\ga 2$ kpc therein even if the jet is initially pair plasma dominated.

  18. ~I R E C TOR' 5 ME 5 5 AGE During 1994, the Jet Propulsion Laboratory (JPL) had many significant ac-

    E-Print Network [OSTI]

    Waliser, Duane E.

    charter for Solar System exploration, Earth observatIons, astrophysical research and technology and builds spacecraft, the way it operates missions and the way it conducts business. Major transformations, but it remains to be seen what directions the new Congressional leadership WIll take. · Sharp cutbacks in Federal

  19. ?Linear Gas Jet with Tailored Density Profile"

    SciTech Connect (OSTI)

    KRISHNAN, Mahadevan

    2012-12-10T23:59:59.000Z

    Supersonic, highly collimated gas jets and gas-filled capillary discharge waveguides are two primary targets of choice for Laser Plasma Accelerators (LPA) . Present gas jets have lengths of only 2-4 mm at densities of 1-4E19 cm-3, sufficient for self trapping and electron acceleration to energies up to ~150 MeV. Capillary structures 3 cm long have been used to accelerate beams up to 1 GeV. Capillary discharges used in LPAs serve to guide the pump laser and optimize the energy gain. A wall-stabilized capillary discharge provides a transverse profile across the channel that helps guide the laser and combat diffraction. Gas injection via a fast nozzle at one end provides some longitudinal density control, to improve the coupling. Gas jets with uniform or controlled density profiles may be used to control electron bunch injection and are being integrated into capillary experiments to add tuning of density. The gas jet for electron injection has not yet been optimized. Our Ph-I results have provided the LPA community with an alternative path to realizing a 2-3GeV electron bunch using just a gas jet. For example, our slit/blade combination gives a 15-20mm long acceleration path with tunable density profile, serving as an alternative to a 20-mm long capillary discharge with gas injection at one end. In Ph-II, we will extend these results to longer nozzles, to see whether we can synthesize 30 or 40-mm long plasma channels for LPAs.

  20. Exciting the quark-gluon plasma with a relativistic jet

    E-Print Network [OSTI]

    Massimo Mannarelli; Cristina Manuel

    2007-06-27T23:59:59.000Z

    We discuss the properties of a system composed by a static plasma traversed by a jet of particles. Assuming that both the jet and the plasma can be described using a hydrodynamical approach, and in the conformal limit, we find that unstable modes arise when the velocity of the jet is larger than the speed of the sound of the plasma and only modes with momenta smaller than a certain values are unstable. Moreover, for ultrarelativistic velocities of the jet the most unstable modes correspond to relative angles between the velocity of the jet and momentum of the collective mode ~ pi/4. Our results suggest an alternative mechanism for the description of the jet quenching phenomenon, where the jet crossing the plasma loses energy exciting colored unstable modes. In LHC this effect should be seen with an enhanced production of hadrons for some specific values of their momenta and in certain directions of momenta space.

  1. Preliminary assessment of high power, NERVA-class dual-mode space nuclear propulsion and power systems

    SciTech Connect (OSTI)

    Buksa, J.J.; Kirk, W.L.; Cappiello, M.W. (Nuclear Technology and Engineering Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (US))

    1991-01-05T23:59:59.000Z

    A preliminary assessment of the technical feasibility and mass competitiveness of a dual-mode nuclear propulsion and power system based on the NERVA rocket engine has been completed. Results indicate that the coupling of the ROVER reactor to a direct Brayton power conversion system can be accomplished through a number of design features. Furthermore, based on previously published and independently calculated component masses, the dual-mode system was found to have the potential to be mass competitive with propulsion/power systems that use separate reactors. The uncertainties of reactor design modification and shielding requirements were identified as important issues requiring future investigation.

  2. New Opportunities for Outer Solar System Science using Radioisotope Electric Propulsion

    SciTech Connect (OSTI)

    Noble, Robert J.; /SLAC; Amini, Rashied; Beauchamp, Patricia M.; /Caltech, JPL; Bennett, Gary L.; /Metaspace Enterprises; Brophy, John R.; Buratti, Bonnie J.; Ervin, Joan; /Caltech, JPL; Fernandez, Yan R.; /Central Florida U.; Grundy, Will; /Lowell Observ.; Khan, Mohammed Omair; /Caltech, JPL; King, David Q.; /Aerojet; Lang, Jared; /Caltech, JPL; Meech, Karen J.; /Hawaii U.; Newhouse, Alan; Oleson, Steven R.; Schmidt, George R.; /GRC; Spilker, Thomas; West, John L.; /Caltech, JPL; ,

    2010-05-26T23:59:59.000Z

    Today, our questions and hypotheses about the Solar System's origin have surpassed our ability to deliver scientific instruments to deep space. The moons of the outer planets, the Trojan and Centaur minor planets, the trans-Neptunian objects (TNO), and distant Kuiper Belt objects (KBO) hold a wealth of information about the primordial conditions that led to the formation of our Solar System. Robotic missions to these objects are needed to make the discoveries, but the lack of deep-space propulsion is impeding this science. Radioisotope electric propulsion (REP) will revolutionize the way we do deep-space planetary science with robotic vehicles, giving them unprecedented mobility. Radioisotope electric generators and lightweight ion thrusters are being developed today which will make possible REP systems with specific power in the range of 5 to 10 W/kg. Studies have shown that this specific power range is sufficient to perform fast rendezvous missions from Earth to the outer Solar System and fast sample return missions. This whitepaper discusses how mobility provided by REP opens up entirely new science opportunities for robotic missions to distant primitive bodies. We also give an overview of REP technology developments and the required next steps to realize REP.

  3. Heavy vehicle propulsion system materials program semiannual progress report for April 1998 thru September 1998

    SciTech Connect (OSTI)

    Johnson, D.R.

    1999-01-01T23:59:59.000Z

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1--3 trucks to realize a 35{percent} fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7--8 trucks. The Office of Transportation Technologies, Office of Heavy Vehicle Technologies (OTT OHVT) has an active program to develop the technology for advanced LE-55 diesel engines with 55{percent} efficiency and low emissions levels of 2.0 g/bhp-h NO{sub x} and 0.05 g/bhp-h particulates. The goal is also for the LE-55 engine to run on natural gas with efficiency approaching that of diesel fuel. The LE-55 program is being completed in FY 1997 and, after approximately 10 years of effort, has largely met the program goals of 55{percent} efficiency and low emissions. However, the commercialization of the LE-55 technology requires more durable materials than those that have been used to demonstrate the goals. Heavy Vehicle Propulsion System Materials will, in concert with the heavy-duty diesel engine companies, develop the durable materials required to commercialize the LE-55 technologies.

  4. Mars mission opportunity and transit time sensitivity for a nuclear thermal rocket propulsion application

    SciTech Connect (OSTI)

    Young, A.C.; Mulqueen, J.A.; Nishimuta, E.L.; Emrich, W.J. (George C. Marshall Space Flight Center, Marshall Space Flight Center, Alabama 35812 (United States))

    1993-01-10T23:59:59.000Z

    President George Bush's 1989 challenge to America to support the Space Exploration Initiative (SEI) of Back to the Moon and Human Mission to Mars'' gives the space industry an opportunity to develop effective and efficient space transportation systems. This paper presents stage performance and requirements for a nuclear thermal rocket (NTR) Mars transportation system to support the human Mars mission of the SEI. Two classes of Mars mission profiles are considered in developing the NTR propulsion vehicle performance and requirements. The two Mars mission classes include the opposition class and conjunction class. The opposition class mission is associated with relatively short Mars stay times ranging from 30 to 90 days and total mission duration of 350 to 600 days. The conjunction class mission is associated with much longer Mars stay times ranging from 500 to 600 days and total mission durations of 875 to 1,000 days. Vehicle mass scaling equations are used to determine the NTR stage mass, size, and performance range required for different Mars mission opportunities and for different Mars mission durations. Mission opportunities considered include launch years 2010 to 2018. The 2010 opportunity is the most demanding launch opportunity and the 2018 opportunity is the least demanding opportunity. NTR vehicle mass and size sensitivity to NTR engine thrust level, engine specific impulse, NTR engine thrust-to-weight ratio, and Mars surface payload are presented. NTR propulsion parameter ranges include those associated with NERVA, particle bed reactor (PBR), low-pressure, and ceramic-metal-type engine design.

  5. Reconciling a Reactionless Propulsive Drive with the First Law of Thermodynamics

    E-Print Network [OSTI]

    Higgins, Andrew J

    2015-01-01T23:59:59.000Z

    A "space drive" is a hypothetical device that generates a propulsive force in free space using an input of power without the need for a reaction mass. Any device that generates photons (e.g., a laser) would qualify as a propellantless "photon rocket," but the force generated by emitting photons per power input (3.33 $\\mu$N/kW) is too small to be a practical propulsion device. The ability to generate greater force per power input would be highly desirable, but, as demonstrated in this paper, such a device would be able to operate as a perpetual motion machine of the first kind. Since applying a constant force results in a constant acceleration, the kinetic energy of a mass driven by such a device increases quadratically with time, while the energy input increases only linearly with time. Thus, at some point, the kinetic energy of the device-driven mass exceeds the energy input, and if this energy is collected via decelerating the mass (via regenerative electromagnetic braking, for example), then there would be...

  6. An Ansatz Regarding Relativistic Space Travel Part II-Propulsion Realities

    SciTech Connect (OSTI)

    Murad, Paul A

    2008-01-21T23:59:59.000Z

    Travel to the stars can involve a perilous journey in an unfriendly space-time continuum that can include singularities, nonlinear events, gravity as a function of both position and vehicle velocity, and extra dimensional effects discussed in Part I. Such a device may possibly use field propulsion technology. Although several field propulsion schemes exist, a proposed candidate is based upon using an electromagnetic drive that uses a rotating magnetic field superimposed on the spacecraft's stationary or static electric field. This is comparable to a Searl generator and the field interaction would generate an electromagnetic vortex to create nonlinear gravitational effects possibly due to an inverse Gertsenshtein relationship to push against the intrinsic gravitational field of a planet. Moreover, changing alignment of the magnetic field axis with the electric field will induce a margin of lateral controllability. Issues such as assessing this combined effect of using both electric and magnetic fields are discussed. Finally, the need for experimental data is stressed to validate these otherwise very speculative theoretical notions.

  7. Hydrogen loops in existing reactors for testing fuel elements for nuclear propulsion

    SciTech Connect (OSTI)

    Olsen, C.S.; Welland, H.; Abraschoff, J. (Idaho National Engineering Laboratory, EG G Idaho Inc., P.O. Box 1625, Idaho Falls, Idaho 83415 (United States)); Thoms, K. (Oak Ridge National Laboratory, P.O. Box, Oak Ridge, Tennessee 37831-8087 (United States))

    1993-01-15T23:59:59.000Z

    The Space Exploration Initiative (SEI) has revitalized interest in adapting nuclear energy for power and propulsion. Prior to the selection of a nuclear thermal propulsion (NTP) system, extensive testing of the various proposed concepts will be required. In today's environmental, safety and health culture, full size rocket engine tests as were done under the Rover/NERVA program will be extremely difficult and expensive to perform and meet NASA's schedules. A different test strategy uses a hydrogen loop in an existing reactor to test a wide variety of single elements or clusters of elements for fuel qualification. This approach is expected to reduce operating and capital costs and expedite the testing schedule. This paper examines the potential of performing subscale tests in a hydrogen loop in an existing reactor such as the Advanced Test Reactor (ATR) at the Idaho National Engineering Laboratory or the High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory. The HFIR is expected to achieve power densities comparable to those achieved in ATR because of the 85 MWt power level and the high thermal and fast flux levels. The available length and diameter of the test region of FHIR are 60 cm and 10 cm whereas the available length and diameter of the test region of ATR are 120 cm and 12 cm respectively.

  8. Propulsion Materials

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn'tOrigin of ContaminationHubs+ ReportEnergy NationalDepartment of31548 Vol. 77, No. 1032

  9. JOURNAL OF PROPULSION AND POWER Vol. 21, No. 1, JanuaryFebruary 2005

    E-Print Network [OSTI]

    Alonso, Juan J.

    -Pressure Turbine Main-/Secondary-Air System Flow Interaction Roger L. Davis University of California, Davis, Davis Global Research Center, Niskayuna, New York 12309 and Roger Paolillo§ and Om P. Sharma¶ Pratt and Whitney flowpath of a modern jet engine transonic high- pressure turbine, transition duct, and first vane

  10. Cryogenic target formation using cold gas jets

    DOE Patents [OSTI]

    Hendricks, Charles D. [Livermore, CA

    1980-02-26T23:59:59.000Z

    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.

  11. Cryogenic target formation using cold gas jets

    DOE Patents [OSTI]

    Hendricks, C.D.

    1980-02-26T23:59:59.000Z

    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.

  12. Azimuthal Jet Tomography at RHIC and LHC

    E-Print Network [OSTI]

    Barbara Betz; Miklos Gyulassy

    2014-02-14T23:59:59.000Z

    A generic jet-energy loss model that is coupled to state-of-the-art hydrodynamic fields and interpolates between a wide class of running coupling pQCD-based and AdS/CFT-inspired models is compared to recent data on the azimuthal and transverse momentum dependence of high-pT pion nuclear modification factors and high-pT elliptic flow measured at RHIC and LHC. We find that RHIC data are surprisingly consistent with various scenarios considered. However, extrapolations to LHC energies favor running coupling pQCD-based models of jet-energy loss. While conformal holographic models are shown to be inconsistent with data, recent non-conformal generalizations of AdS holography may provide an alternative description.

  13. Jet momentum balance independent of shear viscosity

    E-Print Network [OSTI]

    R. B. Neufeld

    2012-02-24T23:59:59.000Z

    Jet momentum balance measurements, such as those recently performed by the CMS collaboration, provide an opportunity to quantify the energy transferred from a parton shower to the underlying medium in heavy-ion collisions. Specifically, I argue that the Cooper-Frye freezeout distribution associated with the energy and momentum deposited by the parton shower is controlled to a significant extent by the distribution of the underlying bulk matter and independent of the details of how deposited energy is redistributed in the medium, which is largely determined by transport coefficients such as shear viscosity. Thus by matching the distribution of momentum associated with the secondary jet in such measurements to the thermal distribution of the underlying medium, one can obtain a model independent estimate on the amount of parton shower energy deposited.

  14. Leading Particle Production in Light Flavour Jets

    E-Print Network [OSTI]

    Abbiendi, G; Ĺkesson, P F; Alexander, Gideon; Allison, J; Anderson, K J; Arcelli, S; Asai, S; Ashby, S F; Axen, D A; Azuelos, Georges; Bailey, I; Ball, A H; Barberio, E; Barlow, R J; Batley, J Richard; Baumann, S; Behnke, T; Bell, K W; Bella, G; Bellerive, A; Bentvelsen, Stanislaus Cornelius Maria; Bethke, Siegfried; Betts, S; Biebel, O; Biguzzi, A; Bloodworth, Ian J; Bock, P; Böhme, J; Boeriu, O; Bonacorsi, D; Boutemeur, M; Braibant, S; Bright-Thomas, P G; Brigliadori, L; Brown, R M; Burckhart, Helfried J; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Chrisman, D; Ciocca, C; Clarke, P E L; Clay, E; Cohen, I; Conboy, J E; Cooke, O C; Couchman, J; Couyoumtzelis, C; Coxe, R L; Cuffiani, M; Dado, S; Dallavalle, G M; Dallison, S; Davis, R; de Roeck, A; Dervan, P J; Desch, Klaus; Dienes, B; Dixit, M S; Donkers, M; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Estabrooks, P G; Etzion, E; Fabbri, Franco Luigi; Fanfani, A; Fanti, M; Faust, A A; Feld, L; Ferrari, P; Fiedler, F; Fierro, M; Fleck, I; Frey, A; Fürtjes, A; Futyan, D I; Gagnon, P; Gary, J W; Gaycken, G; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Gingrich, D M; Glenzinski, D A; Goldberg, J; Gorn, W; Grandi, C; Graham, K; Gross, E; Grunhaus, Jacob; Gruwé, M; Hajdu, C; Hanson, G G; Hansroul, M; Hapke, M; Harder, K; Harel, A; Hargrove, C K; Harin-Dirac, M; Hauschild, M; Hawkes, C M; Hawkings, R; Hemingway, Richard J; Herten, G; Heuer, R D; Hildreth, M D; Hill, J C; Hobson, P R; Höcker, Andreas; Hoffman, K; Homer, R James; Honma, A K; Horváth, D; Hossain, K R; Howard, R; Hüntemeyer, P; Igo-Kemenes, P; Imrie, D C; Ishii, K; Jacob, F R; Jawahery, A; Jeremie, H; Jimack, Martin Paul; Jones, C R; Jovanovic, P; Junk, T R; Kanaya, N; Kanzaki, J I; Karapetian, G V; Karlen, D A; Kartvelishvili, V G; Kawagoe, K; Kawamoto, T; Kayal, P I; Keeler, Richard K; Kellogg, R G; Kennedy, B W; Kim, D H; Klier, A; Kobayashi, T; Kobel, M; Kokott, T P; Kolrep, M; Komamiya, S; Kowalewski, R V; Kress, T; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Kyberd, P; Lafferty, G D; Landsman, Hagar Yaël; Lanske, D; Lauber, J; Lawson, I; Layter, J G; Lellouch, Daniel; Letts, J; Levinson, L; Liebisch, R; Lillich, J; List, B; Littlewood, C; Lloyd, A W; Lloyd, S L; Loebinger, F K; Long, G D; Losty, Michael J; Lü, J; Ludwig, J; Macchiolo, A; MacPherson, A L; Mader, W F; Mannelli, M; Marcellini, S; Marchant, T E; Martin, A J; Martin, J P; Martínez, G; Mashimo, T; Mättig, P; McDonald, W J; McKenna, J A; McKigney, E A; McMahon, T J; McPherson, R A; Meijers, F; Méndez-Lorenzo, P; Merritt, F S; Mes, H; Meyer, I; Michelini, Aldo; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Montanari, A; Mori, T; Nagai, K; Nakamura, I; Neal, H A; Nisius, R; O'Neale, S W; Oakham, F G; Odorici, F; Ögren, H O; Okpara, A N; Oreglia, M J; Orito, S; Pásztor, G; Pater, J R; Patrick, G N; Patt, J; Pérez-Ochoa, R; Petzold, S; Pfeifenschneider, P; Pilcher, J E; Pinfold, James L; Plane, D E; Poli, B; Polok, J; Przybycien, M B; Quadt, A; Rembser, C; Rick, Hartmut; Robins, S A; Rodning, N L; Roney, J M; Rosati, S; Roscoe, K; Rossi, A M; Rozen, Y; Runge, K; Runólfsson, O; Rust, D R; Sachs, K; Saeki, T; Sahr, O; Sang, W M; Sarkisyan-Grinbaum, E; Sbarra, C; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schieck, J; Schmitt, S; Schöning, A; Schröder, M; Schumacher, M; Schwick, C; Scott, W G; Seuster, R; Shears, T G; Shen, B C; Shepherd-Themistocleous, C H; Sherwood, P; Siroli, G P; Skuja, A; Smith, A M; Snow, G A; Sobie, Randall J; Söldner-Rembold, S; Spagnolo, S; Sproston, M; Stahl, A; Stephens, K; Stoll, K; Strom, D; Ströhmer, R; Surrow, B; Talbot, S D; Taras, P; Tarem, S; Teuscher, R; Thiergen, M; Thomas, J; Thomson, M A; Torrence, E; Towers, S; Trefzger, T M; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Van Kooten, R; Vannerem, P; Verzocchi, M; Voss, H; Wäckerle, F; Waller, D; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wetterling, D; White, J S; Wilson, G W; Wilson, J A; Wyatt, T R; Yamashita, S; Zacek, V; Zer-Zion, D

    2000-01-01T23:59:59.000Z

    The energy distribution and type of the particle with the highest momentum in quark jets are determined for each of the five quark flavours making only minimal model assumptions. The analysis is based on a large statistics sample of hadronic Z0 decays collected with the OPAL detector at the LEP e+e- collider. These results provide a basis for future studies of light flavour production at other centre-of-mass energies. We use our results to study the hadronisation mechanism in light flavour jets and compare the data to the QCD models JETSET and HERWIG. Within the JETSET model we also directly determine the suppression of strange quarks to be gamma_s=0.422+-0.049 (stat.)+-0.059 (syst.) by comparing the production of charged and neutral kaons in strange and non-strange light quark events. Finally we study the features of baryon production.

  15. A Fuzzy-Based Strategy to Improve Control Reconfiguration Performance of a Sensor Fault-Tolerant Induction Motor Propulsion

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    utilization of the limited battery capacity (extension of the running distance per battery charge-Tolerant Induction Motor Propulsion Bekheira Tabbache1,2 , Mohamed Benbouzid1 , Abdelaziz Kheloui2 and Jean decision approach. Copyright © 2011 Praise Worthy Prize S.r.l. - All rights reserved. Keywords: Induction

  16. Fundamentals of Propulsion Class/Laboratory Schedule: four lecture hours per week, eight hours outside preparation. 12

    E-Print Network [OSTI]

    Wang, Deli

    and space vehicle propulsion. Analysis and design of gas turbines, inlets, compressors, combustion chambers to formulate and solve problems involving air breathing engines Objective 2 2.1 Student will demonstrate ability to apply principles of analysis to formulate and solve problems involving rockets Objective 3 3

  17. Hydrocarbon-fueled internal combustion engines: "the worst form of vehicle propulsion... except for all the other forms"

    E-Print Network [OSTI]

    Hydrocarbon-fueled internal combustion engines: "the worst form of vehicle propulsion... except of Southern California, Los Angeles, CA 90089-1453 Introduction Hydrocarbon-fueled internal combustion engines towards the use of hydrocarbon fueled internal combustion engines was the discovery of "large" amounts

  18. Power Balance in a Helicon Plasma Source for Space Propulsion Daniel B. White Jr., Manuel Martinez-Sanchez

    E-Print Network [OSTI]

    -Sanchez June 2008 SSL # 9-08 #12;#12;1 Power Balance in a Helicon Plasma Source for Space Propulsion Daniel B. White Jr., Manuel Martinez-Sanchez June 2008 SSL # 9-08 This work is based on the unaltered text

  19. Most fish have a forward undulatory swimming mechanism that involves a kinematic propulsive wave travelling down the

    E-Print Network [OSTI]

    D'Août, Kristiaan

    Most fish have a forward undulatory swimming mechanism that involves a kinematic propulsive wave backwards in a similar way. We compared the kinematics (wave speed, cycle frequency, amplitude, local in the direction opposite to that of swimming. We observe two major kinematic differences. First, the slope of wave

  20. Locomotive Micro-Implant with Active Electromagnetic Propulsion Daniel Pivonka, Ada S. Y. Poon, and Teresa H. Meng

    E-Print Network [OSTI]

    Poon, Ada

    Locomotive Micro-Implant with Active Electromagnetic Propulsion Daniel Pivonka, Ada S. Y. Poon An active locomotive technique requiring only an ex- ternal power source and a static magnetic field is pre- sented, and its operation is analyzed and simulated. For a modest static MRI magnetic field of 1 T

  1. Shielding, Levitation, Propulsion G. W. Jewell, Chariman Method for expanding the uniformly shielded area in a short-length

    E-Print Network [OSTI]

    Paperno, Eugene

    Shielding, Levitation, Propulsion G. W. Jewell, Chariman Method for expanding the uniformly shielded area in a short-length open-ended cylindrical magnetic shield K. Oshita, I. Sasada,a) H. Naka shielded area of the axial magnetic field in a relatively short, open-structure axial magnetic shield can

  2. Technology Survey and Performance Scaling for the Design of High Power Nuclear Electric Power and Propulsion Systems

    E-Print Network [OSTI]

    , use of electric primary propulsion in flight systems has been limited to low-power, solar electric thruster output power are identified. Design evolutions are presented for three thrusters that would1 Technology Survey and Performance Scaling for the Design of High Power Nuclear Electric Power

  3. Tuning the Passive Structural Response of an Oscillating-foil Propulsion Mechanism for Improved Thrust Generation and Efficiency

    E-Print Network [OSTI]

    Victoria, University of

    Thrust Generation and Efficiency by Andrew James Richards B.A.Sc., The University of British Columbia of an Oscillating-foil Propulsion Mechanism for Improved Thrust Generation and Efficiency by Andrew James Richards B for the use of flexible oscillating foils which, under suitable conditions, have been demon- strated

  4. Jet Interaction and the Influence of a Minimum Phase Speed Bound on the Propagation of Eddies

    E-Print Network [OSTI]

    Vallis, Geoff

    Jet Interaction and the Influence of a Minimum Phase Speed Bound on the Propagation of Eddies and analogs of the midlatitude eddy-driven jet and the subtropical jet is investigated in a barotropic b-plane model. In the model the subtropical jet is generated by a relaxation process and the eddy-driven jet

  5. Jet fragmentation and gauge/string duality

    E-Print Network [OSTI]

    Yoshitaka Hatta; Toshihiro Matsuo

    2008-05-27T23:59:59.000Z

    We consider an analog of e^+e^- annihilation in gauge theories which have a dual string description in asymptotically AdS_5 space and discuss the nature of jet fragmentation. We construct the timelike anomalous dimension which governs the scale dependence of the fragmentation function. In the limit of infinite 't Hooft coupling, the average multiplicity rises linearly with the energy and the inclusive spectrum is peaked at the kinematical boundary.

  6. Jet mass with a jet veto at two loops and the universality of non-global structure

    E-Print Network [OSTI]

    Randall Kelley; Matthew D. Schwartz; Robert M. Schabinger; Hua Xing Zhu

    2011-12-14T23:59:59.000Z

    We investigate the exclusive jet mass distribution in e+e- events, defined with a veto on the out-of-jet radiation, at two-loop order. In particular, we calculate the two-loop soft function, which is required to describe this distribution in the threshold region. When combined with other ingredients using soft-collinear effective theory, this generates the complete singular distribution for jet thrust, the sum of the jet masses, at two-loop order. The result is in excellent agreement with full QCD. The integrated jet thrust distribution is found to depend in an intricate way on both the finite jet cone size, R, and the jet veto scale. The result clarifies the structure of the potentially large logarithms (both global and non- global) which arise in jet observables for the first time at this order. Somewhat surprisingly, we find that, in the small R limit, there is a precise and simple correspondence between the non-global contribution to the integrated jet thrust distribution and the previously calculated non-global contribution to the integrated hemisphere soft function, including subleading terms. This suggests that the small R limit may provide a useful expansion for studying other exclusive jet substructure observables.

  7. Jet fire testing of topside pipework

    SciTech Connect (OSTI)

    Boothby, P.J. [British Gas plc, Newcastle upon Tyne (United Kingdom)

    1993-12-31T23:59:59.000Z

    The weight saving potential and inherent corrosion resistance of glass reinforced plastics (GRP) make them attractive candidates for offshore topside seawater piping applications. Glass reinforced plastics, however, comprise a combustible organic matrix, and one of the main areas of concern currently restricting the more widespread use of GRP on offshore platforms in the UK sector of the North Sea is the perceived poor fire endurance of this material. On an offshore platform, the most severe fire scenario envisaged is a hydrocarbon jet fire. A series of large-scale jet fire tests has therefore been conducted at the British Gas Research and Technology Spadeadam test facility, on pipe spools representing the ring main and deluge components of an offshore topside firewater system. The purpose of the tests was to assess the jet fire endurance of GRP with and without passive fire protection coatings, and to compare its performance with existing metallic materials used for this application. The paper presents the results obtained in the first stage of the program addressing the start-up period of firewater system operation when the ring main may contain either stagnant or flowing water and the deluge piping is empty.

  8. Ejector device for direct injection fuel jet

    DOE Patents [OSTI]

    Upatnieks, Ansis (Livermore, CA)

    2006-05-30T23:59:59.000Z

    Disclosed is a device for increasing entrainment and mixing in an air/fuel zone of a direct fuel injection system. The device comprises an ejector nozzle in the form of an inverted funnel whose central axis is aligned along the central axis of a fuel injector jet and whose narrow end is placed just above the jet outlet. It is found that effective ejector performance is achieved when the ejector geometry is adjusted such that it comprises a funnel whose interior surface diverges about 7.degree. to about 9.degree. away from the funnel central axis, wherein the funnel inlet diameter is about 2 to about 3 times the diameter of the injected fuel plume as the fuel plume reaches the ejector inlet, and wherein the funnel length equal to about 1 to about 4 times the ejector inlet diameter. Moreover, the ejector is most effectively disposed at a separation distance away from the fuel jet equal to about 1 to about 2 time the ejector inlet diameter.

  9. Generation of elves by sprites and jets

    SciTech Connect (OSTI)

    Taranenko, Y.; Roussel-Dupre, R.; Yukhimuk, V.; Symbalisty, E.

    1997-04-01T23:59:59.000Z

    Recent years of observations of the upper atmosphere and the lower ionosphere brought a fascinating collection of new phenomena including optical, radio, and gamma-ray emissions originating in the 20 to 90 km altitude range. Up to now, the most diverse phenomenology has emerged from the optical observations which have led to the identification of red sprites, blue jets, blue starts, and elves. Most of the studies have concentrated on relating such phenomena in the upper atmosphere to regular lightning discharges in the troposphere. The sprite/jet discharge itself can be caused by the runaway air breakdown, or regular air breakdown. The standard theory for optical airglow transients in the lower ionosphere above the thunderstorms also known as elves suggests that they are produced during interaction of electromagnetic pulses (EMP) from lightning with the lower ionosphere. Heating of the ambient electrons by the EMP in the D region can result in excitation of optical emissions once the optical excitation thresholds are reached. In this paper the authors suggest that in addition to this mechanism elves can be caused by an EMP generated by sprites and jets.

  10. Power Counting to Better Jet Observables

    E-Print Network [OSTI]

    Andrew J. Larkoski; Ian Moult; Duff Neill

    2014-09-22T23:59:59.000Z

    Optimized jet substructure observables for identifying boosted topologies will play an essential role in maximizing the physics reach of the Large Hadron Collider. Ideally, the design of discriminating variables would be informed by analytic calculations in perturbative QCD. Unfortunately, explicit calculations are often not feasible due to the complexity of the observables used for discrimination, and so many validation studies rely heavily, and solely, on Monte Carlo. In this paper we show how methods based on the parametric power counting of the dynamics of QCD, familiar from effective theory analyses, can be used to design, understand, and make robust predictions for the behavior of jet substructure variables. As a concrete example, we apply power counting for discriminating boosted Z bosons from massive QCD jets using observables formed from the n-point energy correlation functions. We show that power counting alone gives a definite prediction for the observable that optimally separates the background-rich from the signal-rich regions of phase space. Power counting can also be used to understand effects of phase space cuts and the effect of contamination from pile-up, which we discuss. As these arguments rely only on the parametric scaling of QCD, the predictions from power counting must be reproduced by any Monte Carlo, which we verify using Pythia8 and Herwig++. We also use the example of quark versus gluon discrimination to demonstrate the limits of the power counting technique.

  11. Towards an Understanding of the Correlations in Jet Substructure

    E-Print Network [OSTI]

    D. Adams; A. Arce; L. Asquith; M. Backovic; T. Barillari; P. Berta; D. Bertolini; A. Buckley; J. Butterworth; R. C. Camacho Toro; J. Caudron; Y. -T. Chien; J. Cogan; B. Cooper; D. Curtin; C. Debenedetti; J. Dolen; M. Eklund; S. El Hedri; S. D. Ellis; T. Embry; D. Ferencek; J. Ferrando; S. Fleischmann; M. Freytsis; M. Giulini; Z. Han; D. Hare; P. Harris; A. Hinzmann; R. Hoing; A. Hornig; M. Jankowiak; K. Johns; G. Kasieczka; R. Kogler; W. Lampl; A. J. Larkoski; C. Lee; R. Leone; P. Loch; D. Lopez Mateos; H. K. Lou; M. Low; P. Maksimovic; I. Marchesini; S. Marzani; L. Masetti; R. McCarthy; S. Menke; D. W. Miller; K. Mishra; B. Nachman; P. Nef; F. T. O'Grady; A. Ovcharova; A. Picazio; C. Pollard; B. Potter-Landua; C. Potter; S. Rappoccio; J. Rojo; J. Rutherfoord; G. P. Salam; R. M. Schabinger; A. Schwartzman; M. D. Schwartz; B. Shuve; P. Sinervo; D. Soper; D. E. Sosa Corral; M. Spannowsky; E. Strauss; M. Swiatlowski; J. Thaler; C. Thomas; E. Thompson; N. V. Tran; J. Tseng; E. Usai; L. Valery; J. Veatch; M. Vos; W. Waalewijn; J. Wacker; C. Young

    2015-04-15T23:59:59.000Z

    Over the past decade, a large number of jet substructure observables have been proposed in the literature, and explored at the LHC experiments. Such observables attempt to utilize the internal structure of jets in order to distinguish those initiated by quarks, gluons, or by boosted heavy objects, such as top quarks and W bosons. This report, originating from and motivated by the BOOST2013 workshop, presents original particle-level studies that aim to improve our understanding of the relationships between jet substructure observables, their complementarity, and their dependence on the underlying jet properties, particularly the jet radius and jet transverse momentum. This is explored in the context of quark/gluon discrimination, boosted W boson tagging and boosted top quark tagging.

  12. Preliminary Design of a Manned Nuclear Electric Propulsion Vehicle Using Genetic Algorithms

    SciTech Connect (OSTI)

    Irwin, Ryan W. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, IN 47907 (United States); Tinker, Michael L. [Spacecraft and Vehicle Systems Department, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2005-02-06T23:59:59.000Z

    Nuclear electric propulsion (NEP) vehicles will be needed for future manned missions to Mars and beyond. Candidate designs must be identified for further detailed design from a large array of possibilities. Genetic algorithms have proven their utility in conceptual design studies by effectively searching a large design space to pinpoint unique optimal designs. This research combined analysis codes for NEP subsystems with a genetic algorithm. The use of penalty functions with scaling ratios was investigated to increase computational efficiency. Also, the selection of design variables for optimization was considered to reduce computation time without losing beneficial design search space. Finally, trend analysis of a reference mission to the asteroids yielded a group of candidate designs for further analysis.

  13. MCNP benchmark analyses of critical experiments for the Space Nuclear Thermal Propulsion program

    SciTech Connect (OSTI)

    Selcow, E.C.; Cerbone, R.J.; Ludewig, H.; Mughabghab, S.F.; Schmidt, E.; Todosow, M. [Brookhaven National Lab., Upton, NY (United States); Parma, E.J. [Sandia National Labs., Albuquerque, NM (United States); Ball, R.M.; Hoovler, G.S. [Babcock and Wilcox Co., Lynchburg, VA (United States)

    1993-06-01T23:59:59.000Z

    Benchmark analyses have been performed of Particle Bed Reactor (PBR) critical experiments (CX) using the MCNP radiation transport code. The experiments have been conducted at the Sandia National Laboratory reactor facility in support of the Space Nuclear Thermal Propulsion (SNTP) program. The test reactor is a nineteen element water moderated and reflected thermal system. A series of integral experiments have been carried out to test the capabilities of the radiation transport codes to predict the performance of PBR systems. MCNP was selected as the preferred radiation analysis tool for the benchmark experiments. Comparison between experimental and calculational results indicate very good agreement. This paper describes the analyses of benchmark experiments designed to quantify the accuracy of the MCNP radiation transport code for predicting the performance characteristics of PBR reactors.

  14. Propulsion Velocity and ETT on Biomagnetic Assessment of the Human Esophagus

    SciTech Connect (OSTI)

    Cordova-Fraga, T.; Cano, E.; Bravo-Miranda, C.; De la Roca-Chiapas, J. M.; Bernal, J. J.; Sosa, M. [Instituto de Fisica, Universidad de Guanajuato, Loma del Bosque 103, 37150 Leon, Gto. (Mexico); Huerta, R. [Instituto de Investigaciones sobre el Trabajo, Universidad de Guanajuato, Leon, Gto. (Mexico)

    2008-08-11T23:59:59.000Z

    Esophagus transit time measurement is a common clinical practical. Biomagnetic techniques and modern instrumentation can perform non invasive and functional assessments of the gastrointestinal tract. This study presents the evaluation of the esophagus transit time and propulsion velocity of a magnetic marker from the mouth to stomach using water vs. a swallow easy substance recently patented. A group of ten healthy subjects from 45 to 55 years, were evaluated in identical conditions for two times, they ingested randomly a magnetic marker in an anatomical body position of 45 deg., one times with water and the other one with a patented substance developed in order to help the subjects to swallow pills. The esophagus transit time was shorter when the subjects ingested the magnetic marker with the swallow easy substance than they ingested the magnetic marker with same quantity of water.

  15. A bimodal power and propulsion system based on cermet fuel and heat pipe energy transport

    SciTech Connect (OSTI)

    Polansky, G.F. [Sandia National Labs., Albuquerque, NM (United States); Gunther, N.A. [Gunther (Norman A.), San Jose, CA (United States); Rochow, R.F. [Novatech, Lynchburg, VA (United States); Bixler, C.H. [Bixler (Charles H.), Mannford, OK (United States)

    1995-05-01T23:59:59.000Z

    Bimodal space reactor systems provide both thermal propulsion for the spacecraft orbital transfer and electrical power to the spacecraft bus once it is on station. These systems have the potential to increase both the available payload in high energy orbits and the available power to that payload. These increased mass and power capabilities can be used to either reduce mission cost by permitting the use of smaller launch vehicles or to provide increased mission performance from the current launch vehicle. A major barrier to the deployment of these bimodal systems has been the cost associated with their development. This paper describes a bimodal reactor system with performance potential to permit more than 70% of the instrumented payload of the Titan IV/Centaur to be launched from the Atlas IIAS. The development cost is minimized by basing the design on existing component technologies.

  16. A review of carbide fuel corrosion for nuclear thermal propulsion applications

    SciTech Connect (OSTI)

    Pelaccio, D.G.; El-Genk, M.S. [Univ. of New Mexico, Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies; Butt, D.P. [Los Alamos National Lab., NM (United States)

    1993-12-01T23:59:59.000Z

    At the operation conditions of interest in nuclear thermal propulsion reactors, carbide materials have been known to exhibit a number of life limiting phenomena. These include the formation of liquid, loss by vaporization, creep and corresponding gas flow restrictions, and local corrosion and fuel structure degradation due to excessive mechanical and/or thermal loading. In addition, the radiation environment in the reactor core can produce a substantial change in its local physical properties, which can produce high thermal stresses and corresponding stress fractures (cracking). Time-temperature history and cyclic operation of the nuclear reactor can also accelerate some of these processes. The University of New Mexico`s Institute for Space Nuclear Power Studies, under NASA sponsorship has recently initiated a study to model the complicated hydrogen corrosion process. In support of this effort, an extensive review of the open literature was performed, and a technical expert workshop was conducted. This paper summarizes the results of this review.

  17. Propulsion system for a motor vehicle using a bidirectional energy converter

    DOE Patents [OSTI]

    Tamor, Michael Alan (Toledo, OH); Gale, Allan Roy (Livonia, MI)

    1999-01-01T23:59:59.000Z

    A motor vehicle propulsion system includes an electrical energy source and a traction motor coupled to receive electrical energy from the electrical energy source. The system also has a first bus provided electrical energy by the electrical energy source and a second bus of relatively lower voltage than the first bus. In addition, the system includes an electrically-driven source of reaction gas for the electrical energy source, the source of reaction gas coupled to receive electrical energy from the first bus. Also, the system has an electrical storage device coupled to the second bus for storing electrical energy at the lower voltage. The system also includes a bidirectional energy converter coupled to convert electrical energy from the first bus to the second bus and from the second bus to the first bus.

  18. Absence of jamming in ant trails: Feedback control of self propulsion and noise

    E-Print Network [OSTI]

    Chaudhuri, Debasish

    2014-01-01T23:59:59.000Z

    We present a model of ant traffic considering individual ants as self-propelled particles undergoing single file motion on a one-dimensional trail. Recent experiments on unidirectional ant traffic in well-formed natural trails showed that the collective velocity of ants remains approximately unchanged, leading to absence of jamming even at very high densities [ John et. al., Phys. Rev. Lett. 102, 108001 (2009) ]. Assuming a feedback control mechanism of self-propulsion force generated by each ant using information about the distance from the ant in front, our model captures all the main features observed in the experiment. The distance headway distribution shows a maximum corresponding to separations within clusters. The position of this maximum remains independent of average number density. We find a non-equilibrium first order transition, with the formation of an infinite cluster at a threshold density where all the ants in the system suddenly become part of a single cluster.

  19. Propulsion System Materials Program semiannual progress report for April 1995 through September 1995

    SciTech Connect (OSTI)

    NONE

    1996-04-01T23:59:59.000Z

    Significant accomplishments in fabricating ceramic components for the DOE, NASA, and DOD advanced heat engine programs have provided evidence that the operation of ceramic parts in high-temperature engine environments is feasible. These programs have also demonstrated that additional research is needed in materials and processing development, design methodology, and data base and life prediction before industry will have a sufficient technology base from which to produce reliable cost-effective ceramic engine components commercially. An assessment of needs was completed, and a 5-year program plan was developed with extensive input from private industry. During the course of the Propulsion System Materials Program, remarkable progress has been made in the development of reliable structural ceramics. However, further work is needed to reduce the cost of ceramics to facilitate their commercial introduction, especially in the highly cost-sensitive automotive market. To this end, the direction of the Propulsion System Materials Program is now shifting toward reducing the cost of ceramics to facilitate commercial introduction of ceramic components for near-term engine applications. In response to extensive input from industry, the plan is to extend the engine types which were previously supported to include near-term (5--10 years) applications in conventional automobile and diesel truck engines. To facilitate the rapid transfer of this technology to US industry, the major portion of the work is being done in the ceramic industry, with technological support from government laboratories, other industrial laboratories, and universities. A systematic approach to reducing the cost of components is envisioned. The work elements are as follows: economic cost modeling, ceramic machining, powder synthesis, alternative forming and densification processes, yield improvement, system design studies, standards development, low-expansion ceramics, and testing and data base development.

  20. Heavy vehicle propulsion system materials program: Semiannual progress report, April 1996--September 1996

    SciTech Connect (OSTI)

    Johnson, D.R.

    1997-04-01T23:59:59.000Z

    The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks. The Office of Transportation Technologies, Office of Heavy Vehicle Technologies (OTT OHVT) has an active program to develop the technology for advanced LE-55 diesel engines with 55% efficiency and low emissions levels of 2.0 g/bhp-h NO{sub x} and 0.05 g/bhp-h particulates. The goal is also for the LE-55 engine to run on natural gas with efficiency approaching that of diesel fuel. The LE-55 program is being completed in FY 1997 and, after approximately 10 years of effort, has largely met the program goals of 55% efficiency and low emissions. However, the commercialization of the LE-55 technology requires more durable materials than those that have been used to demonstrate the goals. Heavy Vehicle Propulsion System Materials will, in concert with the heavy duty diesel engine companies, develop the durable materials required to commercialize the LE-55 technologies. OTT OHVT also recognizes a significant opportunity for reduction in petroleum consumption by dieselization of pickup trucks, vans, and sport utility vehicles. Application of the diesel engine to class 1, 2, and 3 trucks is expected to yield a 35% increase in fuel economy per vehicle. The foremost barrier to diesel use in this market is emission control. Once an engine is made certifiable, subsequent challenges will be in cost; noise, vibration, and harshness (NVH); and performance. Separate abstracts have been submitted to the database for contributions to this report.

  1. CONTROL OF COHERENT STRUCTURE IN COAXIAL SWIRLING TURBULENT JETS

    E-Print Network [OSTI]

    Lee, Wonjoong

    2008-01-01T23:59:59.000Z

    .............................................................. 193 xvi NOMENCLATURE Symbol Description Unit D Jet diameter, Defined in Figure 5.1 m D h Hydraulic jet diameter m f Excitation frequency s -1 G Degree of swirl, Defined... stronger effect than the pilot jet itself, leading to an almost entire removal of coherent structures. 2.2. Flow Instability Swirl is naturally presented in the exhaust from a turbine or an axial flow pump, and may be deliberately generated...

  2. Adiabatic expansion and magnetic fields in AGN jets

    E-Print Network [OSTI]

    A. B. Pushkarev; Y. Y. Kovalev; A. P. Lobanov

    2008-12-25T23:59:59.000Z

    Results of high-resolution simultaneous multi-frequency 8.1-15.4 GHz VLBA polarimetric observations of relativistic jets in active galactic nuclei (the MOJAVE-2 project) are analyzed. We compare characteristics of VLBI features with jet model predictions and test if adiabatic expansion is a dominating mechanism for the evolution of relativistic shocks in parsec-scale AGN jets. We also discuss magnetic field configuration, both predicted by the model and deduced from electric vector position angle measurements.

  3. Reconstructing top quark-antiquark events with one lost jet

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

    Demina, Regina [Univ. of Rochester, Rochester, NY (United States); Harel, Amnon [Univ. of Rochester, Rochester, NY (United States); Orbaker, Douglas [Univ. of Rochester, Rochester, NY (United States)

    2015-07-01T23:59:59.000Z

    We present a technique for reconstructing the kinematics of pair-produced top quarks that decay to a charged lepton, a neutrino and four final state quarks in the subset of events where only three jets are reconstructed. We present a figure of merit that allows for a fair comparison of reconstruction algorithms without requiring their calibration. The new reconstruction of events with only three jets is fully competitive with the full reconstruction typically used for four-jet events.

  4. Jet Substructure Templates: Data-driven QCD Backgrounds for Fat Jet Searches

    E-Print Network [OSTI]

    Timothy Cohen; Martin Jankowiak; Mariangela Lisanti; Hou Keong Lou; Jay G. Wacker

    2014-10-20T23:59:59.000Z

    QCD is often the dominant background to new physics searches for which jet substructure provides a useful handle. Due to the challenges associated with modeling this background, data-driven approaches are necessary. This paper presents a novel method for determining QCD predictions using templates -- probability distribution functions for jet substructure properties as a function of kinematic inputs. Templates can be extracted from a control region and then used to compute background distributions in the signal region. Using Monte Carlo, we illustrate the procedure with two case studies and show that the template approach effectively models the relevant QCD background. This work strongly motivates the application of these techniques to LHC data.

  5. acetylene jet diffusion: Topics by E-print Network

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

    for emission produced in various kinds of astrophysical jets, in particular, prompt gamma-ray burst spectra, including X-ray excesses and prompt optical flashes. Gregory D....

  6. COLLIMATION AND CONFINEMENT OF MAGNETIC JETS BY EXTERNAL MEDIA

    SciTech Connect (OSTI)

    Levinson, Amir [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel)] [School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Begelman, Mitchell C., E-mail: Levinson@wise.tau.ac.il, E-mail: mitch@jila.colorado.edu [JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, CO 80309-0440 (United States)

    2013-02-20T23:59:59.000Z

    We study the collimation of a highly magnetized jet by a surrounding cocoon that forms as a result of the interaction of the jet with the external medium. We show that in regions where the jet is well confined by the cocoon, current-driven instabilities should develop over timescales shorter than the expansion time of the jet's head. We speculate that these instabilities would give rise to complete magnetic field destruction, whereby the jet undergoes a transition from high to low sigma above the collimation zone. Using this assumption, we construct a self-consistent model for the evolution of the jet-cocoon system in an ambient medium of arbitrary density profile. We apply the model to jet breakout in long gamma-ray bursts (GRBs) and show that the jet is highly collimated inside the envelope of the progenitor star and is likely to remain confined well after breakout. We speculate that this strong confinement may provide a channel for magnetic field conversion in GRB outflows, whereby the hot, low-sigma jet section thereby produced is the source of the photospheric emission observed in many bursts.

  7. Cherenkov Radiation from Jets in Heavy-ion Collisions

    E-Print Network [OSTI]

    Koch, Volker; Majumder, Abhijit; Wang, Xin-Nian

    2005-01-01T23:59:59.000Z

    Wiley & Son, Inc. Cherenkov radiation leads to energy lossLBNL-58447 Cherenkov Radiation from Jets in Heavjion Nuclearthe occurrence of Cherenkov radiation in dense matter is

  8. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Lietava, R; Pisútová, N; Tomasik, Boris; Lietava, Roman; Pisut, Jan; Pisutova, Neva; Tomasik, Boris

    2003-01-01T23:59:59.000Z

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  9. asian jet stream: Topics by E-print Network

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

    Laboratory Kidston, Joseph 11 Rayleigh Wave-Internal Wave Coupling and Internal Wave Generation Above a Model Jet Stream Mathematics Websites Summary: Rayleigh...

  10. Infrared imaging results of an excited planar jet

    SciTech Connect (OSTI)

    Farrington, R.B.

    1991-12-01T23:59:59.000Z

    Planar jets are used for many applications including heating, cooling, and ventilation. Generally such a jet is designed to provide good mixing within an enclosure. In building applications, the jet provides both thermal comfort and adequate indoor air quality. Increased mixing rates may lead to lower short-circuiting of conditioned air, elimination of dead zones within the occupied zone, reduced energy costs, increased occupant comfort, and higher indoor air quality. This paper discusses using an infrared imaging system to show the effect of excitation of a jet on the spread angle and on the jet mixing efficiency. Infrared imaging captures a large number of data points in real time (over 50,000 data points per image) providing significant advantages over single-point measurements. We used a screen mesh with a time constant of approximately 0.3 seconds as a target for the infrared camera to detect temperature variations in the jet. The infrared images show increased jet spread due to excitation of the jet. Digital data reduction and analysis show change in jet isotherms and quantify the increased mixing caused by excitation. 17 refs., 20 figs.

  11. An alternative model of jet suppression at RHIC energies

    E-Print Network [OSTI]

    Roman Lietava; Jan Pisut; Neva Pisutova; Boris Tomasik

    2003-02-10T23:59:59.000Z

    We propose a simple Glauber-type mechanism for suppression of jet production up to transverse momenta of about 10 GeV/c at RHIC. For processes in this kinematic region, the formation time is smaller than the interval between two successive hard partonic collisions and the subsequent collision influences the jet production. Number of jets then roughly scales with the number of participants. Proportionality to the number of binary collisions is recovered for very high transverse momenta. The model predicts suppression of jet production in d+Au collisions at RHIC.

  12. SYNCHROTRON RADIATION OF SELF-COLLIMATING RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    SciTech Connect (OSTI)

    Porth, Oliver; Fendt, Christian; Vaidya, Bhargav [Max Planck Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Meliani, Zakaria, E-mail: porth@mpia.de, E-mail: fendt@mpia.de [Centre for Plasma Astrophysics, K. U. Leuven, Celestijnenlaan 200B, 3001 Leuven (Belgium)

    2011-08-10T23:59:59.000Z

    The goal of this paper is to derive signatures of synchrotron radiation from state-of-the-art simulation models of collimating relativistic magnetohydrodynamic (MHD) jets featuring a large-scale helical magnetic field. We perform axisymmetric special relativistic MHD simulations of the jet acceleration region using the PLUTO code. The computational domain extends from the slow-magnetosonic launching surface of the disk up to 6000{sup 2} Schwarzschild radii allowing jets to reach highly relativistic Lorentz factors. The Poynting-dominated disk wind develops into a jet with Lorentz factors of {Gamma} {approx_equal} 8 and is collimated to 1{sup 0}. In addition to the disk jet, we evolve a thermally driven spine jet emanating from a hypothetical black hole corona. Solving the linearly polarized synchrotron radiation transport within the jet, we derive very long baseline interferometry radio and (sub-) millimeter diagnostics such as core shift, polarization structure, intensity maps, spectra, and Faraday rotation measure (RM) directly from the Stokes parameters. We also investigate depolarization and the detectability of a {lambda}{sup 2}-law RM depending on beam resolution and observing frequency. We find non-monotonic intrinsic RM profiles that could be detected at a resolution of 100 Schwarzschild radii. In our collimating jet geometry, the strict bimodality in the polarization direction (as predicted by Pariev et al.) can be circumvented. Due to relativistic aberration, asymmetries in the polarization vectors across the jet can hint at the spin direction of the central engine.

  13. Tail Emission of Prompt Gamma-Ray Burst Jets

    E-Print Network [OSTI]

    Yamazaki, R; Ioka, K; Nakamura, T; Yamazaki, Ryo; Toma, Kenji; Ioka, Kunihito; Nakamura, Takashi

    2006-01-01T23:59:59.000Z

    Tail emission of the prompt gamma-ray burst is discussed using a multiple emitting sub-shell (inhomogeneous jet, sub-jets) model. The tail is a superposition of a number of smooth, long-duration, dim, and soft pulses emitted by segments located far from the line of sight. We find that the behavior of the tail is not so much affected by the local inhomogeneity but affected by the global sub-jet distribution. Some observed tails may disfavor the power-law jets.

  14. Electrical characteristics and formation mechanism of atmospheric pressure plasma jet

    SciTech Connect (OSTI)

    Liu, Lijuan; Zhang, Yu; Tian, Weijing; Meng, Ying; Ouyang, Jiting, E-mail: jtouyang@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

    2014-06-16T23:59:59.000Z

    The behavior of atmospheric pressure plasma jet produced by a coplanar dielectric barrier discharge in helium in external electrostatic and magnetic field is investigated. Net negative charges in the plasma jet outside the tube were detected. The deflection of the plume in the external field was observed. The plasma jet is suggested to be formed by the electron beam from the temporal cathode which is accelerated by a longitudinal field induced by the surface charges on the dielectric tube or interface between the helium and ambient air. The helium flow is necessary for the jet formation in the surrounding air.

  15. High Multiplicity Searches at the LHC Using Jet Masses

    SciTech Connect (OSTI)

    Hook, Anson; /SLAC /Stanford U., Appl. Phys. Dept.; Izaguirre, Eder; /SLAC /Stanford U., Phys. Dept.; Lisanti, Mariangela; /Princeton U.; Wacker, Jay G.; /SLAC /Stanford U., ITP

    2012-04-24T23:59:59.000Z

    This article introduces a new class of searches for physics beyond the Standard Model that improves the sensitivity to signals with high jet multiplicity. The proposed searches gain access to high multiplicity signals by reclustering events into large-radius, or 'fat', jets and by requiring that each event has multiple massive jets. This technique is applied to supersymmetric scenarios in which gluinos are pair-produced and then subsequently decay to final states with either moderate quantities of missing energy or final states without missing energy. In each of these scenarios, the use of jet mass improves the estimated reach in gluino mass by 20% to 50% over current LHC searches.

  16. Geographic Area Month Aviation Gasoline Kerosene-Type Jet Fuel

    U.S. Energy Information Administration (EIA) Indexed Site

    Excluding Taxes) - Continued Geographic Area Month Aviation Gasoline Kerosene-Type Jet Fuel Kerosene Sales to End Users Sales for Resale Sales to End Users Sales for Resale...

  17. Microhole Arrays Drilled With Advanced Abrasive Slurry Jet Technology...

    Open Energy Info (EERE)

    Microhole Arrays Drilled With Advanced Abrasive Slurry Jet Technology To Efficiently Exploit Enhanced Geothermal Systems Geothermal Project Jump to: navigation, search Last...

  18. Parsec-Scale Jet-Environment Interactions in AGN

    E-Print Network [OSTI]

    Matthew L. Lister

    2007-07-12T23:59:59.000Z

    Observations made with the VLBA have led to fundamental advances in our understanding of how radio jets in AGN evolve from parsec-scales out to distances exceeding several hundred kiloparsecs. In this review I discuss current models of young radio source evolution, as well as the observational evidence for a rapid change in jet properties on scales of ~1 kpc. A central topic of current debate is the relative importance of intermittent jet fueling versus jet-environment interactions in causing a drop-off in powerful radio sources at this critical evolutionary stage. Recent 3-D hydrodynamical jet simulations suggest that dense environments and cloud collisions can temporarily stifle, but not completely halt powerful relativistic jets. Several VLBA studies of jet-ISM interactions in both blazars and weak Seyfert jets have indicated that collimated outflows are indeed possible in dense environments. At present, the bulk of the evidence favors intermittent AGN accretion as the dominant factor in determining the evolutionary path of large numbers of AGN jets.

  19. Primary Atomization of a Liquid Jet in Crossflow

    E-Print Network [OSTI]

    Rana, Sandeep

    2010-01-01T23:59:59.000Z

    In this fluid dynamics video, we present a visualization of the primary atomization of a turbulent liquid jet injected into a turbulent gaseous crossflow. It is based on a detailed numerical simulation of the primary atomization region of the jet using a finite volume, balanced force, incompressible LES/DNS flow solver coupled to a Refined Level Set Grid (RLSG) solver to track the phase interface position. The visualization highlights the two distinct breakup modes of the jet: the column breakup mode of the main liquid column and the ligament breakup mode on the sides of the jet and highlights the complex evolution of the phase interface geometry.

  20. Environmental and economic assessment of microalgae-derived jet fuel

    E-Print Network [OSTI]

    Carter, Nicholas Aaron

    2012-01-01T23:59:59.000Z

    Significant efforts must be undertaken to quantitatively assess various alternative jet fuel pathways when working towards achieving environmental and economic United States commercial and military alternative aviation ...