Science.gov

Sample records for all-metal vacuum chamber

  1. Bakeout Chamber Within Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Taylor, Daniel M.; Soules, David M.; Barengoltz, Jack B.

    1995-01-01

    Vacuum-bakeout apparatus for decontaminating and measuring outgassing from pieces of equipment constructed by mounting bakeout chamber within conventional vacuum chamber. Upgrade cost effective: fabrication and installation of bakeout chamber simple, installation performed quickly and without major changes in older vacuum chamber, and provides quantitative data on outgassing from pieces of equipment placed in bakeout chamber.

  2. IRIS Leaves Thermal Vacuum Chamber

    NASA Video Gallery

    This video shows the transportation of the IRIS observatory from the thermal vacuum chamber back to the clean tent for final testing and preparations for delivery to the launch site at Vandenberg A...

  3. Impedances of Laminated Vacuum Chambers

    SciTech Connect

    Burov, A.; Lebedev, V.; /Fermilab

    2011-06-22

    First publications on impedance of laminated vacuum chambers are related to early 70s: those are of S. C. Snowdon [1] and of A. G. Ruggiero [2]; fifteen years later, a revision paper of R. Gluckstern appeared [3]. All the publications were presented as Fermilab preprints, and there is no surprise in that: the Fermilab Booster has its laminated magnets open to the beam. Being in a reasonable mutual agreement, these publications were all devoted to the longitudinal impedance of round vacuum chambers. The transverse impedance and the flat geometry case were addressed in more recent paper of K. Y. Ng [4]. The latest calculations of A. Macridin et al. [5] revealed some disagreement with Ref. [4]; this fact stimulated us to get our own results on that matter. Longitudinal and transverse impendances are derived for round and flat laminated vacuum chambers. Results of this paper agree with Ref. [5].

  4. Compact all-metal high-vacuum gate valve for microwave tube research

    NASA Astrophysics Data System (ADS)

    Gold, Steven H.; Kinkead, Allen K.; Nezhevenko, Oleg A.

    1999-09-01

    A manually operated all-metal high-vacuum bakable gate valve is described that is designed to attach between an electron gun and an experimental high-power microwave tube. It is designed with a minimal radial extent in order to fit within the 20 cm bore of a magnet that encloses the microwave tube. It also provides a continuous cylindrical metal boundary condition for the electron beam. The valve is used to maintain the electron gun vacuum when the remainder of the tube is brought up to atmospheric pressure for modifications.

  5. Vacuum chamber for an undulator straight section

    SciTech Connect

    Kim, S.; Wehrle, R.; Genens, L.

    1987-01-01

    A prototype aluminum extruded vacuum chamber for an undulator straight section of the Advanced Photon Source is described. The 52.-m long vacuum system is designed so that the undulator gap variation does not interfere with it. The chamber is gripped in a stiff close toleranced mounting structure to insure dimensional tolerance of the chamber height.

  6. TSNIIMASH's U-22 gasdynamic vacuum chamber

    NASA Astrophysics Data System (ADS)

    Anfimov, N. A.; Prochukhaev, M. V.

    1993-06-01

    The description of operating principles of the TSNIIMASH's U-22 large-scale gasdynamic vacuum chamber is presented. The chamber's key systems and their performances are described. Examples of using the gasdynamic vacuum chamber for conducting experimental research and ground testing of rockets, launch vehicles and spacecraft are given.

  7. Test stand system for vacuum chambers

    NASA Technical Reports Server (NTRS)

    Newman, D. F. (Inventor)

    1973-01-01

    A test stand system for supporting test items in a vacuum chamber is described. The system consists of a frame adapted to conform to the inside of the vacuum chamber and supporting a central vertical shaft. The shaft rotates on bearings located at each end of the shaft. Several vertically spaced plates which fixed to the vertical shaft may be adjusted for height to support the test equipment as required. The test equipment may be rotated during tests without disturbing the vacuum by a manually actuated drive external to the vacuum chamber.

  8. Thermal Vacuum Chamber Repressurization with Instrument Purging

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael S.

    2014-01-01

    At the conclusion of cryogenic vacuum testing of the James Webb Space Telescope Optical Telescope Element Integrated Science Instrument Module (JWST-OTIS) in NASA Johnson Space Center’s (JSCs) thermal vacuum (TV) Chamber A, contamination control (CC) engineers are postulating that chamber particulate material stirred up by the repressurization process may be kept from falling into the Integrated Science Instrument Module (ISIM) interior to some degree by activating instrument purge flows over some initial period before opening the chamber valves. This manuscript describes development of a series of models designed to describe this process. The models are strung together in tandem with a fictitious set of conditions to estimate overpressure evolution from which net outflow velocity behavior may be obtained. Creeping flow assumptions are then used to determine the maximum particle size that may be kept suspended above the ISIM aperture, keeping smaller particles from settling within the instrument module.

  9. Thermal Vacuum Chamber Repressurization with Instrument Purging

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2016-01-01

    At the end of James Webb Space Telescope (JWST) OTIS (Optical Telescope Element-OTE-Integrated Science Instrument Module-ISIM) cryogenic vacuum testing in NASA Johnson Space Centers (JSCs) thermal vacuum (TV) Chamber A, contamination control (CC) engineers are mooting the idea that chamber particulate material stirred up by the repressurization process may be kept from falling into the ISIM interior to some degree by activating instrument purge flows over some initial period before opening the chamber valves. This memo describes development of a series of models designed to describe this process. These are strung together in tandem to estimate overpressure evolution from which net outflow velocity behavior may be obtained. Creeping flow assumptions are then used to determine the maximum particle size that may be kept suspended above the ISIM aperture, keeping smaller particles from settling within the instrument module.

  10. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and...

  11. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and...

  12. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards....423 Cheese vacuumizing chamber. The vacuum chamber shall be satisfactorily constructed and...

  13. Vacuum-cleaning System for Isolation Chambers

    PubMed Central

    Yale, Charles E.

    1969-01-01

    To encourage the utilization of the isolation chamber as a research tool, the cost of its use should be lowered. Methods and devices must be developed which make more efficient use of the space within the isolator and allow the operator to work more effectively in this confined area. A simple vacuum-cleaning system is described; it consists of a nozzle and flexible hose which connect through the isolator wall to an externally placed waste tank, attached by way of its outlet filter to a source of vacuum. The cylindrical waste tank [48 inches (1.219 m) high and 36 inches (0.914 m) in diameter] was sterilized in a large autoclave. During a 9-month test period, the system was used to remove soiled corncob bedding from a large isolator containing 90 adult monocontaminated rats. During this period, the microbial flora of the isolator was unchanged, and the time required to clean the cages was reduced by 50%. This vacuum-cleaning system is a safe, convenient, and economical means of increasing the efficiency of an isolation chamber. Images PMID:5775913

  14. Vacuum chamber for containing particle beams

    DOEpatents

    Harvey, A.

    1985-11-26

    A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer such as nickel can be coated on the inside of the pipe.

  15. Vacuum chamber for containing particle beams

    DOEpatents

    Harvey, Alexander

    1987-01-01

    A vacuum chamber for containing a charged particle beam in a rapidly changing magnetic environment comprises a ceramic pipe with conducting strips oriented along the longitudinal axis of the pipe and with circumferential conducting bands oriented perpendicular to the longitudinal axis but joined with a single longitudinal electrical connection. When both strips and bands are on the outside of the ceramic pipe, insulated from each other, a high-resistance conductive layer, such as nickel can be coated on the inside of the pipe.

  16. Advanced photon source experience with vacuum chambers for insertion devices

    SciTech Connect

    Hartog, P.D.; Grimmer, J.; Xu, S.; Trakhtenberg, E.; Wiemerslage, G.

    1997-08-01

    During the last five years, a new approach to the design and fabrication of extruded aluminum vacuum chambers for insertion devices was developed at the Advanced Photon Source (APS). With this approach, three different versions of the vacuum chamber, with vertical apertures of 12 mm, 8 mm, and 5 mm, were manufactured and tested. Twenty chambers were installed into the APS vacuum system. All have operated with beam, and 16 have been coupled with insertion devices. Two different vacuum chambers with vertical apertures of 16 mm and 11 mm were developed for the BESSY-II storage ring and 3 of 16 mm chambers were manufactured.

  17. Quartz crystals detect gas contaminants during vacuum chamber evacuation

    NASA Technical Reports Server (NTRS)

    Stephens, J. B.

    1967-01-01

    Piezoelectric quartz crystals detect condensable gas contaminants backstreaming into a vacuum chamber when a pump is evacuating the chamber. One crystal acts as a thermometer, the other detects mass change. They are energized by electronic equipment which records frequency changes.

  18. DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING ...

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

    DETAIL OF VACUUM PIPE OPENING WITHIN ALTITUDE CHAMBER R, FACING SOUTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  19. Space Station Live: Historic Vacuum Chamber to Test Webb Telescope

    NASA Video Gallery

    NASA Public Affairs Officer Dan Huot recently visited Johnson Space Center’s 400,000 cubic foot vacuum chamber, Chamber A, and spoke with Mary Cerimele, the lab manager for this historic facility.

  20. Phoenix Lowered into Thermal Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Phoenix Mars Lander was lowered into a thermal vacuum chamber at Lockheed Martin Space Systems, Denver, in December 2006.

    The spacecraft was folded in its aeroshell and underwent environmental testing that simulated the extreme conditions the spacecraft will see during its nine-and-a-half-month cruse to Mars.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

  1. NOVEL CHAMBER DESIGN FOR AN IN-VACUUM CRYO-COOLED MINI-GAP UNDULATOR.

    SciTech Connect

    HU, J.-P.; FOERSTER, C.L.; SKARITKA, J.R.; WATERMAN, D.

    2006-05-24

    A stainless steel, Ultra-High Vacuum (UHV) chamber, featuring a large vertical rectangular port (53''W by 16''H), has been fabricated to house the one-meter magnet assembly of a newly installed undulator insertion device for beamline X-25 at the National Synchrotron Light Source. To achieve UHV, the new chamber is equipped with a differential ion pump, NEG pump, nude ion gauge, residual gas analyzer, and an all metal roughing valve. Temperature of the magnet assembly is maintained below 90 C during vacuum bake. The large rectangular port cover is sealed to the main flange of the chamber using a one-piece flat aluminum gasket and special sealing surfaces developed exclusively by Nor-Cal Products, Inc. The large flange provides easy access to the gap of the installed magnet girders for in situ magnetic measurements and shimming. Special window ports were designed into the cover and chamber for manipulation of optical micrometers external to the chamber to provide precise measurements of the in-vacuum magnet gap. The vacuum chamber assembly features independently vacuum-isolated feedthroughs that can be used for either water-or-cryogenic refrigeration-cooling of the monolithic magnet girders. This would allow for cryogenic-cooled permanent magnet operation and has been successfully tested within temperature range of +100 C to -150 C. Details of the undulator assembly for beamline X-25 is described in the paper.

  2. Vacuum Chamber for the Measurement System of the Beam Energy

    NASA Astrophysics Data System (ADS)

    Abakumova, E.; Achasov, M.; Dong, HaiYi; Qu, HuaMin; Krasnov, A.; Kosarev, A.; Muchnoi, N.; Pyata, E.; Xiao, Qiong; Mo, XiaoHu; Wang, YiFang; Zhukov, A.

    Vacuum chamber for the beam energy measurement system based on the Compton backscattering method is presented. The main elements of the chamber are GaAs entrance viewport and a copper mirror. The viewport design provides baking out of the vacuum chamber up to 250 °C. To produce the viewport, an original technology based on brazing GaAs plate by lead has been developed. The vacuum chambers were installed at the BEPC-II and VEPP-4 M colliders. After installation the residual gas pressure is about 10-10 Torr.

  3. Feed-through connector couples RF power into vacuum chamber

    NASA Technical Reports Server (NTRS)

    Grandy, G. L.

    1967-01-01

    Feed-through device connects RF power to an RF coil in a vacuum chamber. The coil and leads are water cooled and vacuum tight seals are provided at the junctions. The device incorporates silver soldered copper tubes, polytetrafluoroethylene electrical insulators, and O-ring vacuum seals.

  4. Vacuum chamber with a supersonic-flow aerodynamic window

    DOEpatents

    Hanson, C.L.

    1980-10-14

    A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  5. Vacuum chamber with a supersonic flow aerodynamic window

    DOEpatents

    Hanson, Clark L.

    1982-01-01

    A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  6. Students Speak With Vacuum Chamber Project Manager Mary Cerimele

    NASA Video Gallery

    From the International Space Station Flight Control Room at NASA's Johnson Space Center, Vacuum Chamber A Project Manager Mary Cerimele participates in a Digital Learning Network (DLN) event with s...

  7. Vacuum chamber-free centrifuge with magnetic bearings

    NASA Astrophysics Data System (ADS)

    Park, Cheol Hoon; Kim, Soohyun; Kim, Kyung-Soo

    2013-09-01

    Centrifuges are devices that separate particles of different densities and sizes through the application of a centrifugal force. If a centrifuge could be operated under atmospheric conditions, all vacuum-related components such as the vacuum chamber, vacuum pump, diffusion pump, and sealing could be removed from a conventional centrifuge system. The design and manufacturing procedure for centrifuges could then be greatly simplified to facilitate the production of lightweight centrifuge systems of smaller volume. Furthermore, the maintenance costs incurred owing to wear and tear due to conventional ball bearings would be eliminated. In this study, we describe a novel vacuum chamber-free centrifuge supported by magnetic bearings. We demonstrate the feasibility of the vacuum chamber-free centrifuge by presenting experimental results that verify its high-speed support capability and motoring power capacity.

  8. APS storage ring vacuum chamber: Section 1, Evaluation

    SciTech Connect

    Benaroya, R.; Roop, B.

    1995-07-01

    The vacuum characteristics of the APS storage ring vacuum chamber prototype, Section One (S1), is presented. The base pressure achieved was 4 {times} 10{sup {minus}11}, the welds contained no virtual or real leaks, the NeG strip mounting design and activation procedures have been determined, and S1 was found contaminated with hydrocarbons.

  9. 13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE ...

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

    13. VIEW OF VACUUM CHAMBER AND WELDING EQUIPMENT IN MODULE E. PARTS WERE WELDED UNDER A VACUUM TO PREVENT CORROSION. (11/6/73) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  10. 14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM ...

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

    14. VIEW OF VACUUM COATING CHAMBER. THE SYSTEM USED TITANIUM VAPORS TO DEPOSIT TITANIUM COATING ONTO URANIUM PARTS UNDER A VACUUM. (1/11/83) - Rocky Flats Plant, Non-Nuclear Production Facility, South of Cottonwood Avenue, west of Seventh Avenue & east of Building 460, Golden, Jefferson County, CO

  11. Safety shield for vacuum/pressure chamber viewing port

    NASA Technical Reports Server (NTRS)

    Shimansky, R. A.; Spencer, R. S. (Inventor)

    1981-01-01

    Observers are protected from flying debris resulting from a failure of a vacuum or pressure chamber viewing port following an implosion or explosion by an optically clear shatter resistant safety shield which spaced apart from the viewing port on the outer surface of the chamber.

  12. Ion chambers simplify absolute intensity measurements in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Sampson, J. A. R.

    1966-01-01

    Single or double ion chamber technique measures absolute radiation intensities in the extreme vacuum ultraviolet region of the spectrum. The ion chambers use rare gases as the ion carrier. Photon absorbed by the gas creates one ion pair so a measure of these is a measure of the number of incident photons.

  13. Extreme-UV lithography vacuum chamber zone seal

    DOEpatents

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2003-04-08

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  14. Extreme-UV lithography vacuum chamber zone seal

    DOEpatents

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2003-04-15

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  15. Extreme-UV lithography vacuum chamber zone seal

    DOEpatents

    Haney, Steven J.; Herron, Donald Joe; Klebanoff, Leonard E.; Replogle, William C.

    2001-01-01

    Control of particle contamination on the reticle and carbon contamination of optical surfaces in photolithography systems can be achieved by the establishment of multiple pressure zones in the photolithography systems. The different zones will enclose the reticle, projection optics, wafer, and other components of system. The system includes a vacuum apparatus that includes: a housing defining a vacuum chamber; one or more metrology trays situated within the vacuum chamber each of which is supported by at least one support member, wherein the tray separates the vacuum chamber into a various compartments that are maintained at different pressures; and conductance seal devices for adjoining the perimeter of each tray to an inner surface of the housing wherein the tray is decoupled from vibrations emanating from the inner surface of the housing.

  16. Novel method for cleaning a vacuum chamber from hydrocarbon contamination

    SciTech Connect

    Wanzenboeck, H. D.; Roediger, P.; Hochleitner, G.; Bertagnolli, E.; Buehler, W.

    2010-11-15

    A novel method for cleaning a high vacuum chamber is presented. This method is based on concurrent in situ high-energetic UV light activation of contaminants located in the residual gas and at the vacuum chamber surfaces as well as the in situ generation of highly reactive ozone. Ozone oxidizes the contaminants to volatile species. Investigations by energy-dispersive x-ray analysis of residual gas depositions and mass-spectroscopy measurements of the residual gas in the vacuum chamber identify the contaminant species as hydrocarbons. After a cleaning period of 8 h, a decrease in measured chamber contamination by about 90% could be achieved according to atomic force microscope analysis. Mass spectroscopy measurements using a residual gas analyzer indicate the creation of volatile, carbonaceous species during the cleaning process.

  17. Vacuum Chamber Design of NSLS-II Storage Ring

    SciTech Connect

    Doom,L.; Ferreira, M.; Hseuh, H. C.; Lincoln, F.; Longo, C.; Ravindranath, V.; Sharma, S.

    2008-06-11

    National Synchrotron Light Source II (NSLS II) will be a 3-GeV, 792-meter circumference, 3rd generation synchrotron radiation facility, with ultra low emittance and extremely high brightness. the storage ring has 30 Double-Bend-Achromatic (DBA) cells. in each cell, there are five magnets and chamber girders, and one straight section for insertion devices or Radio Frequency (RF) cavities or injection. Most vacuum chambers are made from extruded aluminum with two different cross sections: one fitted in the dipole magnets, and the other surrounded by multipole magnets. They discuss the layout of the DBA cells, the detailed design of the cell's vacuum chambers, the mounting of the Beam-Position-Monitor (BPM) buttons, discrete absorbers, lumped pumps and the distributed Non-Evaporable Getter (NEG) strips, and describe the fabrication and testing of these prototype cell chambers. The account also details the development of the chamber bakeout process, the NEG stri's supports, and the RF shielded bellows.

  18. Chamber B Thermal/Vacuum Chamber: User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Montz, Mike E.

    2012-01-01

    Test process, milestones and inputs are unknowns to first-time users of Chamber B. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  19. Rogue Mode Shileding in NSLS-II Multipole Vacuum Chambers

    SciTech Connect

    Ferreira, M.; Blednykh, A.; Bacha, B.; Borrelli, A.; Hseuh, H.-C.; Kosciuk, B.; Krinsky, S.; Singh, O.; Vetter, K.

    2011-03-28

    Modes with transverse electric field (TE-modes) in the NSLS-II multipole vacuum chamber can be generated at frequencies above 450MHz due to its geometric dimensions. Since the NSLS-II BPM system monitors signals within 10 MHz band at RF frequency of 500 MHz, frequencies of higher-order modes (HOM) can be generated within the transmission band of the band pass filter. In order to avoid systematic errors in the NSLS-II BPM system, we introduced frequency shift of HOMs by using RF metal shielding located in the antechamber slot. We demonstrated numerical modeling and experimental studies of the spurious TE modes in the NSLS-II vacuum chambers with antechamber slot. Calculated frequencies of TE-modes in considered chambers with and without RF shielding were verified experimentally. Flexible BeCu RF shielding inside each chamber at proper location shifts frequencies of H{sub 10p}-modes above {approx}900MHz, except chambers S6 odd and even. These chambers need special attention because of synchrotron radiation from downstream magnets. S6 odd multipole vacuum chamber needs to be measured and the RF shielding length has to be optimized. RF shielding looks adequate for baseline design. Fifty percent of open space provides adequate pumping speed.

  20. The PEP-II Lower Pressure HER Vacuum Chamber

    SciTech Connect

    DeBarger, S.; Metcalfe, S.; Seeman, J.; Sullivan, M.; Wienands, U.; Wright, D.; /SLAC

    2006-03-13

    This new vacuum chamber has been installed from 12 to 21 meters upstream of the BaBar detector in the PEP-II High Energy Ring (HER) to reduce lost particle backgrounds. The backgrounds from HER now dominate the backgrounds in the BaBar detector and the present vacuum pressure is 1 x 10{sup -9} Torr. The new chamber will increase the pumping significantly by adding 18 x 2000 l/s titanium sublimation pumps to the existing 5 x 440 l/s ion pumps, and is expected to reduce the pressure by about a factor of five. Features of the chamber include improved water cooling, improved vacuum conductance through copper RF screens featuring over 15,000 small square holes and the ability to sublimate titanium while the beam is still on.

  1. DEVELOPMENT OF TITANIUM NITRIDE COATING FOR SNS RING VACUUM CHAMBERS.

    SciTech Connect

    HE,P.; HSEUH,H.C.; MAPES,M.; TODD,R.; WEISS,D.

    2001-06-18

    The inner surface of the ring vacuum chambers of the US Spallation Neutron Source (SNS) will be coated with {approximately}100 nm of Titanium Nitride (TiN). This is to minimize the secondary electron yield (SEY) from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Both DC sputtering and DC-magnetron sputtering were conducted in a test chamber of relevant geometry to SNS ring vacuum chambers. Auger Electron Spectroscopy (AES) and Rutherford Back Scattering (RBS) were used to analyze the coatings for thickness, stoichiometry and impurity. Excellent results were obtained with magnetron sputtering. The development of the parameters for the coating process and the surface analysis results are presented.

  2. Astronaut Story Musgrave in EMU in thermal vacuum chamber

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Astronaut F. Story Musgrave, wearing a training version of the extravehicular activity unit (EMU), particpates in a dry run for tests in thermal vacuum chamber. The test, conducted in Chamber B ofthe Space Environment and Simulation Laboratory at JSC, verified that the tools being designed for the mission will work in the cold vacuum of space. Others pictured, from the left, are Andrea Tullar and Donna Fender, test directors; Leonard S. Nicholson, acting Director of engineering; and Astronauts Thomas D. Akers and Kathryn C. Thornton, STS-61 mission specialists, along with Musgrave.

  3. Optimization of a vacuum chamber for vibration measurements

    NASA Astrophysics Data System (ADS)

    Danyluk, Mike; Dhingra, Anoop

    2011-10-01

    A 200 °C high vacuum chamber has been built to improve vibration measurement sensitivity. The optimized design addresses two significant issues: (i) vibration measurements under high vacuum conditions and (ii) use of design optimization tools to reduce operating costs. A test rig consisting of a cylindrical vessel with one access port has been constructed with a welded-bellows assembly used to seal the vessel and enable vibration measurements in high vacuum that are comparable with measurements in air. The welded-bellows assembly provides a force transmissibility of 0.1 or better at 15 Hz excitation under high vacuum conditions. Numerical results based on design optimization of a larger diameter chamber are presented. The general constraints on the new design include material yield stress, chamber first natural frequency, vibration isolation performance, and forced convection heat transfer capabilities over the exterior of the vessel access ports. Operating costs of the new chamber are reduced by 50% compared to a preexisting chamber of similar size and function.

  4. Cleaning of a thermal vacuum chamber with shrouds in place

    NASA Technical Reports Server (NTRS)

    Bond, William R.

    1992-01-01

    In February, 1991, a failure of a rotary booster pump caused the diffusion pumps to backstream into a 10 ft x 15 ft thermal vacuum chamber. Concerns existed about the difficulty of removing and reinstalling the shrouds without causing leaks. The time required for the shroud removal was also of concern. These concerns prompted us to attempt to clean the chamber without removing the shrouds.

  5. Environmental Testing in Thermal Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Inside a thermal vacuum at Lockheed Martin Space Systems, Denver, technicians prepare NASA's Phoenix Mars Lander for environmental testing.

    The Phoenix lander was encapsulated in its aeroshell -- which included both the back shell and heat shield -- as it was subjected to extreme cold and heat in a vacuum, space-like condition. The spacecraft undergoes extensive environmental testing to confirm Phoenix will perform in the extreme conditions it will experience during its trip from Earth to Mars, during its arrival and landing, and while it works on the surface of Mars.

    The Phoenix mission is led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory and development partnership with Lockheed Martin Space Systems. International contributions for Phoenix are provided by the Canadian Space Agency, the University of Neuchatel (Switzerland), the University of Copenhagen, and the Max Planck Institute in Germany. JPL is a division of the California Institute of Technology in Pasadena.

  6. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT...

  7. Impedance of a small-gap undulator vacuum chamber

    SciTech Connect

    Bane, K.; Krinsky, S.

    1993-07-01

    Insertion device performance is limited by the minimum magnet gap allowed by storage ring beam dynamics. In this note, we analyze the impedance of the vacuum chamber for the prototype small-gap undulator being built for the NSLS X-Ray ring, and discuss the consequent beam instability thresholds.

  8. 7 CFR 58.423 - Cheese vacuumizing chamber.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Cheese vacuumizing chamber. 58.423 Section 58.423 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT...

  9. Vacuum chamber for ion manipulation device

    SciTech Connect

    Chen, Tsung-Chi; Tang, Keqi; Ibrahim, Yehia M; Smith, Richard D; Anderson, Gordon A; Baker, Erin M

    2014-12-09

    An ion manipulation method and device is disclosed. The device includes a pair of substantially parallel surfaces. An array of inner electrodes is contained within, and extends substantially along the length of, each parallel surface. The device includes a first outer array of electrodes and a second outer array of electrodes. Each outer array of electrodes is positioned on either side of the inner electrodes, and is contained within and extends substantially along the length of each parallel surface. A DC voltage is applied to the first and second outer array of electrodes. A RF voltage, with a superimposed electric field, is applied to the inner electrodes by applying the DC voltages to each electrode. Ions either move between the parallel surfaces within an ion confinement area or along paths in the direction of the electric field, or can be trapped in the ion confinement area. A predetermined number of pairs of surfaces are disposed in one or more chambers, forming a multiple-layer ion mobility cyclotron device.

  10. Impedance analysis of the PEP-II vacuum chamber

    SciTech Connect

    Ng, C.K.; Weiland, T.

    1995-05-01

    The PEP-II high energy ring (HER) vacuum chamber consists of a copper tube with periodically spaced pumping slots. The impedance of the vacuum chamber due to the slots is analyzed. Both narrow-band and broadband impedances are considered as well as longitudinal and transverse components thereof. It is found that although the broad-band impedance is tolerable, the narrow-band impedance may exceed the instability limit given by the natural damping with no feedback system on. Traveling wave modes in the chamber are the major source of this high value narrow-band impedance. We also study the dependences of the impedance on the slot length and the geometrical cross section.

  11. In situ measurement of ceramic vacuum chamber conductive coating quality

    SciTech Connect

    Doose, C.; Harkay, K.; Kim, S.; Milton, S.

    1997-08-01

    A method for measuring the relative surface resistivity and quality of conductive coatings on ceramic vacuum chambers was developed. This method is unique in that it allows one to test the coating even after the ceramic chamber is installed in the accelerator and under vacuum; furthermore, the measurement provides a localized surface reading of the coating conductance. The method uses a magnetic probe is calibrated using the measured DC end-to-end resistance of the tube under test and by comparison to a high quality test surface. The measurement method has also been verified by comparison to high frequency impedance measurements. A detailed description, results, and sensitivity of the technique are given here.

  12. A Comparison of Outgassing Measurements for Three Vacuum Chamber Materials

    SciTech Connect

    M. L. Stutzman; P. Adderley; B. M. Poelker; M. Baylac; J. Clark; A. Day; J. Grames; J. Hansknecht; G. R. Myneni; P. M. Rutt; C. K. Sinclair

    2002-11-01

    Outgassing measurements of three UHV materials (304 Stainless Steel (SS), 316L SS and 6061T-6 aluminum) were made using the conductance and accumulation techniques as given in the AVS Recommended Practice for Outgassing Measurements [ ]. Measurement results indicate good agreement between the two techniques. This study was undertaken to help determine the vacuum limitations of the photoelectron guns used at Jefferson Lab and to aid in the choice of vacuum chamber materials that will be used in the construction of future photoelectron guns. The outgassing rate measured for all of the chamber materials, regardless of technique, was about 1 X 10{sup -12} Torr{sup -}l/s{sup -}cm{sup 2}.

  13. Theoretical and numerical studies of plume flows in vacuum chambers

    NASA Astrophysics Data System (ADS)

    Cai, Chunpei

    This thesis consists of three parts: a study of facility effects on the background flow in large vacuum chambers; an analytical study of free molecular flows out of exits with different shape representing thruster plumes; and particle simulations of plasma plume flows from a cluster of Hall thrusters. The first part of this thesis discusses the facility effects on large vacuum chambers, which is quite important to the Electric Propulsion (EP) community. Based on the fact that the background flows in large vacuum chambers equipped with cryogenic pumps are free molecular, five models are proposed to study the average background pressure and flow velocity and their relation to several facility effects, such as pump sticking coefficient, pump size, wall and pump temperatures, and chamber sidewall length. The analysis are based on the mass flow rates into and out of the chamber, the fluxes along two directions and various number density relations at various stations such as chamber ends and vacuum pumps. The second part of the thesis develops several sets of analytical solutions to free molecular flows out of exits with different shapes. It is demonstrated that the plasma plume flows expanding into vacuum can be studied analytically as a combination of several free molecular flows, if the electric field and collision effects are omitted. There exists a unique relation of velocity and positions. The last part of the thesis presents several three-dimensional particle simulations of plasma plume flows from a cluster of Hall thrusters. A detailed electron fluid model is used to solve important electron properties such as plasma potential and electron temperature. A finite element solver is developed to solve the equations of the electron properties on unstructured meshes. Several important implementation issues are discussed and one significant finding is that the class of particle-to-node weighting schemes based on areas or volumes on an unstructured mesh is inaccurate

  14. SUMMARY ON TITANIUM NITRIDE COATING OF SNS RING VACUUM CHAMBERS.

    SciTech Connect

    TODD, R.; HE, P.; HSEUH, H.C.; WEISS, D.

    2005-05-16

    The inner surfaces of the 248 m Spallation Neutron Source (SNS) accumulator ring vacuum chambers are coated with {approx}100nm of titanium nitride (TiN) to reduce the secondary electron yield (SEY) of the chamber walls. There are approximately 135 chambers and kicker modules, some up to 5m in length and 36cm in diameter, coated with TiN. The coating is deposited by means of reactive DC magnetron sputtering -using a - cylindrical cathode with internal permanent magnets. This cathode configuration generates a deposition-rate sufficient to meet the required production schedule and produces stoichiometric films with good adhesion, low SEY and acceptable outgassing. Moreover, the cathode magnet configuration allows for simple changes in length and has been adapted to coat the wide variety of chambers and components contained within the arcs, injection, extraction, collimation and RF straight sections. Chamber types and quantities as well as the cathode configurations are presented herein. The unique coating requirements of the injection kicker ceramic chambers and the extraction kicker ferrite surface will be emphasized. A brief summary of the salient coating properties is given including the interdependence of SEY as a function of surface roughness and its effect on outgassing.

  15. In-Situ Focusing Inside a Thermal Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Hannah, Brett; Bartman, Randall; Radulescu, Costin; Rud, Mayer; Sarkissian, Edwin; Ho, Timothy; {p; Esposito, Joseph; Sutin, Brian; Haring, Robert; Gonzalez, Juan

    2010-01-01

    Traditionally, infrared (IR) space instruments have been focused by iterating with a number of different thickness shim rings in a thermal vacuum chamber until the focus meets requirements. This has required a number of thermal cycles that are very expensive as they tie up many integration and test (I&T)/ environmental technicians/engi neers work ing three shifts for weeks. Rather than creating a test shim for each iteration, this innovation replaces the test shim and can focus the instrument while in the thermal vacuum chamber. The focus tool consists of three small, piezo-actuated motors that drive two sets of mechanical interface flanges between the instrument optics and the focal- plane assembly, and three optical-displacement metrology sensors that can be read from outside the thermal vacuum chamber. The motors are used to drive the focal planes to different focal distances and acquire images, from which it is possible to determine the best focus. At the best focus position, the three optical displacement metrology sensors are used to determine the shim thickness needed. After the instrument leaves the thermal vacuum chamber, the focus tool is replaced with the precision-ground shim ring. The focus tool consists of two sets of collars, one that mounts to the backside of the interface flange of the instrument optics, and one that mounts to the backside of the interface flange of the focal plane modules. The collars on the instrument optics side have the three small piezo-actuated motors and the three optical displacement metrology systems. Before the instrument is focused, there is no shim ring in place and, therefore, no fasteners holding the focal plane modules to the cameras. Two focus tooling collars are held together by three strong springs. The Orbiting Carbon Observatory (OCO) mission spectrometer was focused this way (see figure). The motor described here had to be moved five times to reach an acceptable focus, all during the same thermal cycle, which

  16. Design, Installation and Commissioning of new Vacuum chamber for Analysing Magnet of K-130 Cyclotron

    NASA Astrophysics Data System (ADS)

    Mandal, Bidhan Chandra; Saha, S.; Sarkar, S. C.; Adak, D.; Viswanathan, T.; Hemram, B.; Chakraborty, P. S.; Yadav, R. C.; Mallik, C.; Bhandari, R. K.

    2012-11-01

    In view of up-gradation of K-130 Cyclotron at VECC, Kolkata, we have designed a new Vacuum chamber to modify the existing vacuum chamber system. This new chamber is meant for C-shaped 1T dipole type 159.5° Analysing Magnet of 4710 OD × 2750 ID × 1075 mm tall in the RIB feeder beam-line. The welded type vacuum chamber is made of SS-304. The chamber with trapezoidal cross-section is of 4447 OD × 4057 ID × 61.5 mm average height. Pumping ports and modules are selected accordingly to ensure the required high vacuum for beam transport. The chamber improves the base vacuum and reduces the complicated O-ring replacement mandatory for existing chamber made of aluminium alloy. The new chamber is installed at site along with all the pumping module and beam line components. This paper presents the detailed design, installation and commissioning results.

  17. Refurbishment of a 39 foot thermal vacuum chamber

    NASA Technical Reports Server (NTRS)

    Edwards, Arthur A.

    1994-01-01

    The 39' thermal vacuum chamber at Space Systems/Loral has been used to test numerous spacecraft including those of the GOES, Intelsat, Insat, Superbird, N-Star, NATO and other programs. Ten years ago, the aluminum LN2 shroud experienced serious fatigue failures in the field welded jumper tubing, effectively shutting down the chamber for vacuum testing. The problem was repaired at the time, but new failures began to reappear a few months ago and are now occurring at a rate that suggests that the shroud may again become inoperable. Consequently, Space Systems/Loral is spending in excess of $6 million to replace the shroud and the existing LN2 equipment with a new, state of the art cryogenic system. In May, 1994, a contract was awarded to remove the existing shroud and LN2 pumping system and replace it with a gravity fed shroud and distribution system. Included in the contract are eight skid mounted gaseous nitrogen pumping systems capable of controlling shroud zone temperatures between +150 C and -180 C. The project is scheduled to be completed in April 1995.

  18. Focal Point Inside the Vacuum Chamber for Solar Thermal Propulsion

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Researchers at the Marshall Space Flight Center (MSFC) have designed, fabricated, and tested the first solar thermal engine, a non-chemical rocket engine that produces lower thrust but has better thrust efficiency than a chemical combustion engine. MSFC turned to solar thermal propulsion in the early 1990s due to its simplicity, safety, low cost, and commonality with other propulsion systems. Solar thermal propulsion works by acquiring and redirecting solar energy to heat a propellant. The 20- by 24-ft heliostat mirror (not shown in this photograph) has dual-axis control that keeps a reflection of the sunlight on an 18-ft diameter concentrator mirror, which then focuses the sunlight to a 4-in focal point inside the vacuum chamber. The focal point has 10 kilowatts of intense solar power. This photograph is a close-up view of a 4-in focal point inside the vacuum chamber at the MSFC Solar Thermal Propulsion Test facility. As part of MSFC's Space Transportation Directorate, the Propulsion Research Center serves as a national resource for research of advanced, revolutionary propulsion technologies. The mission is to move the Nation's capabilities beyond the confines of conventional chemical propulsion into an era of aircraft-like access to Earth orbit, rapid travel throughout the solar system, and exploration of interstellar space.

  19. DETAIL OF VACUUM PIPE AT 0’0” LEVEL, ALTITUDE CHAMBER R, ...

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

    DETAIL OF VACUUM PIPE AT 0’-0” LEVEL, ALTITUDE CHAMBER R, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  20. Microwave longitudinal coupling impedance in ISABELLE vacuum chamber

    SciTech Connect

    Giordano, S.; Votruba, J.

    1980-03-01

    The purpose of this paper is to investigate the modes above the cutoff frequency of the ISABELLE vacuum chamber, and to measure some typical values of the longitudinal coupling impedance. (The investigation was limited to only those modes that have fields in the beam pipe.) Measurements show that the impedance, Z, between 2.6 and 2.8 GHz, can be as high as 10 x n ohms, where n is the ratio of the excitation frequency of the beam divided by the fundamental rotational frequency of the ISABELLE ring. Future work calls for an investigation of the coupling impedance above 2.8 GHz; preliminary work indicates that these impedances Z/n, can be considerably higher than 10 ohms.

  1. Small gap magnets and vacuum chambers for eRHIC

    SciTech Connect

    Meng,W.; Bengtsson, J.; Hao, Y.; Mahler, G.; Tuozzolo, J.; Litvinenko, V. N.

    2009-05-04

    eRHIC[1][2][3], a future high luminosity electron-ion collider at Brookhaven National Laboratory (BNL), will add polarized electrons to the list of colliding species in RHIC. A 10-30 GeV electron energy recovery linac (ERL) will require up to six passes around the RHIC 3.8 km circumference. We are developing and testing small (5 mm) gap dipole and quadrupole magnets and vacuum chambers for cost-effective eRHIC passes [4]. We are also studying the sensitivity of eRHIC pass optics to magnet and alignment errors in such a small magnet structure. We present the magnetic and mechanical designs of the small gap eRHIC components and prototyping test progress.

  2. Secondary magnetic field harmonics dependence on vacuum beam chamber geometry

    NASA Astrophysics Data System (ADS)

    Shim, S. Y.; Wilfert, S.; Muehle, C.

    2013-08-01

    The harmonic magnetic field properties due to eddy currents have been studied with respect to the geometry of the vacuum beam chamber. We derived a generalized formula enabling the precise prediction of any field harmonics generated by eddy currents in beam tubes with different cross-sectional geometries. Applying our model to study the properties of field harmonics in beam tubes with linear dipole magnetic field ramping clearly proved that the circular cross section tube generates only a dipole field from eddy currents. The elliptic tube showed noticeable magnitudes of sextupole and dipole fields. We demonstrate theoretically that it is feasible to suppress the generation of the sextupole field component by appropriately varying the tube wall thickness as a function of angle around the tube circumference. This result indicates that it is possible to design an elliptical-shaped beam tube that generates a dipole field component with zero magnitude of sextupole. In a rectangular-shaped beam tube, one of the selected harmonic fields can be prevented if an appropriate wall thickness ratio between the horizontal and vertical tube walls is properly chosen. Our generalized formalism can be used for optimization of arbitrarily complex-shaped beam tubes, with respect to suppression of detrimental field harmonics.

  3. Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

    NASA Technical Reports Server (NTRS)

    Routh, D. E.; Sharma, G. C. (Inventor)

    1984-01-01

    An apparatus is disclosed which includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a dc magnetron sputtering system. A gas inlet introduces various gases to the vacuum chamber and creates various gas plasma during the sputtering steps. The rotating turntables insure that the respective wafers are present under the sputtering guns for an average amount of time such that consistency in sputtering and deposition is achieved. By continuous and sequential processing of the wafers in a common vacuum chamber without removal, the adverse affects of exposure to atmospheric conditions are eliminated providing higher quality circuit contacts and functional device.

  4. Method for sequentially processing a multi-level interconnect circuit in a vacuum chamber

    NASA Technical Reports Server (NTRS)

    Routh, D. E.; Sharma, G. C. (Inventor)

    1982-01-01

    The processing of wafer devices to form multilevel interconnects for microelectronic circuits is described. The method is directed to performing the sequential steps of etching the via, removing the photo resist pattern, back sputtering the entire wafer surface and depositing the next layer of interconnect material under common vacuum conditions without exposure to atmospheric conditions. Apparatus for performing the method includes a vacuum system having a vacuum chamber in which wafers are processed on rotating turntables. The vacuum chamber is provided with an RF sputtering system and a DC magnetron sputtering system. A gas inlet is provided in the chamber for the introduction of various gases to the vacuum chamber and the creation of various gas plasma during the sputtering steps.

  5. A large high vacuum, high pumping speed space simulation chamber for electric propulsion

    NASA Technical Reports Server (NTRS)

    Grisnik, Stanley P.; Parkes, James E.

    1994-01-01

    Testing high power electric propulsion devices poses unique requirements on space simulation facilities. Very high pumping speeds are required to maintain high vacuum levels while handling large volumes of exhaust products. These pumping speeds are significantly higher than those available in most existing vacuum facilities. There is also a requirement for relatively large vacuum chamber dimensions to minimize facility wall/thruster plume interactions and to accommodate far field plume diagnostic measurements. A 4.57 m (15 ft) diameter by 19.2 m (63 ft) long vacuum chamber at NASA Lewis Research Center is described. The chamber utilizes oil diffusion pumps in combination with cryopanels to achieve high vacuum pumping speeds at high vacuum levels. The facility is computer controlled for all phases of operation from start-up, through testing, to shutdown. The computer control system increases the utilization of the facility and reduces the manpower requirements needed for facility operations.

  6. Vibration study of the APS storage ring vacuum-chamber/girder assembly

    SciTech Connect

    Jendrzejczyk, J.A.; Wambsganss, M.W.; Smith, R.K.

    1991-02-01

    The overall objective of this study is to obtain insights into the dynamic coupling between the storage ring vacuum chamber and girder, and an assessment of the potential for unacceptable vibration amplitudes that would require redesign of the vacuum chamber supports. Specific objectives include determination of the vibrational characteristics (natural frequencies and modes) of the coupled vacuum-chamber/girder system, measurement of response amplitudes to forced excitation and ambient floor motion, and calculation of magnification factors associated with the various coupled vibration modes. 1 ref.

  7. The development of a portable ultrahigh vacuum chamber via silicon block

    NASA Astrophysics Data System (ADS)

    Chuang, Ho-Chiao; Huang, Chia-Shiuan

    2014-05-01

    This paper describes a nonmetallic, light weight portable chamber for ultra-high vacuum (UHV) applications. The chamber consists of a processed silicon block anodically bonding five polished Pyrex glass windows and a Pyrex glass adapter, without using any screws, bolts or vacuum adhesives. The design features provide an alternative chamber for UHV applications which require nonmetallic components. We have cyclically baked the chamber up to 180 °C for 160 h and have achieved an ultimate pressure of 1.4 × 10-9 Torr (limited by our pumping station), with no leak detected. Both Pyrex glass windows and Pyrex glass adapter have been used successfully.

  8. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, G.T.; Jackson, J.W.

    1990-03-19

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations (dB/dt) in the particle beam.

  9. Method of correcting eddy current magnetic fields in particle accelerator vacuum chambers

    DOEpatents

    Danby, Gordon T.; Jackson, John W.

    1991-01-01

    A method for correcting magnetic field aberrations produced by eddy currents induced in a particle accelerator vacuum chamber housing is provided wherein correction windings are attached to selected positions on the housing and the windings are energized by transformer action from secondary coils, which coils are inductively coupled to the poles of electro-magnets that are powered to confine the charged particle beam within a desired orbit as the charged particles are accelerated through the vacuum chamber by a particle-driving rf field. The power inductively coupled to the secondary coils varies as a function of variations in the power supplied by the particle-accelerating rf field to a beam of particles accelerated through the vacuum chamber, so the current in the energized correction coils is effective to cancel eddy current flux fields that would otherwise be induced in the vacuum chamber by power variations in the particle beam.

  10. Development of a large low-cost double-chamber vacuum laminator

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1983-01-01

    A double-chamber vacuum laminator was required to investigate the processing and control of the fabrication of large terrestrial photovoltaic modules, and economic problems arising therefrom. Major design considerations were low cost, process flexibility and the exploration of novel equipment approaches. Spherical end caps for industrial tanks were used for the vacuum chambers. A stepping programmer and adjustable timers were used for process flexibility. New processing options were obtained by use of vacuum sensors. The upper vacuum chamber was provided with a diaphragm support to reduce diaphragm stress. A counterweight was used for handling ease and safety. Heat was supplied by a large electrical strip heater. Thermal isolation and mechanical support were provided inexpensively by a bed of industrial marbles. Operational testing disclosed the need for a differential vacuum gauge and proportional valve. Reprogramming of the process control system was simple and quick.

  11. The thin-wall tube drift chamber operating in vacuum (prototype)

    NASA Astrophysics Data System (ADS)

    Alexeev, G. D.; Glonti, L. N.; Kekelidze, V. D.; Malyshev, V. L.; Piskun, A. A.; Potrbenikov, Yu. K.; Rodionov, V. K.; Samsonov, V. A.; Tokmenin, V. V.; Shkarovskiy, S. N.

    2013-08-01

    The goal of this work was to design drift tubes and a chamber operating in vacuum, and to develop technologies for tubes independent assembly and mounting in the chamber. These design and technology were tested on the prototype. The main features of the chamber are the following: the drift tubes are made of flexible mylar film (wall thickness 36 μm, diameter 9.80 mm, length 2160 mm) using ultrasonic welding along the generatrix; the welding device and methods were developed at JINR. Drift tubes with end plugs, anode wires and spacers were completely assembled outside the chamber. "Self-centering" spacers and bushes were used for precise setting of the anode wires and tubes. The assembled tubes were sealed with O-rings in their seats in the chamber which simplified the chamber assembling. Moreover the tube assembly and the chamber manufacture can be performed independently and in parallel; this sufficiently reduces the total time of chamber manufacture and assembling, its cost and allows tubes to be tested outside the chamber. The technology of independent tube assembling is suitable for a chamber of any shape but a round chamber is preferable for operation in vacuum. Single channel amplifier-discriminator boards which are more stable against cross talks were used for testing the tubes. Independently assembled tubes were mounted into the chamber prototype and its performance characteristic measured under the vacuum conditions. The results showed that both the structure and the tubes themselves normally operate. They are suitable for making a full-scale drift chamber for vacuum.

  12. Ceramic torodail vacuum chamber and wall conditioning for the ETL-TPE-2 experiment

    SciTech Connect

    Kiyama, H.; Kiyama, S.; Hakoda, K.

    1981-01-01

    TPE-2 is a torodial high /beta/screw pinch experiment with an ellitical cross section. This paper presents the design and the fabrication of the torodial ceramic vacuum chamber, the outline of the vacuum system and of major radius of 40 cm and an elliptical cross section of 28 cm.

  13. Vacuum-chamber simulation of high-voltage breakdown in space

    NASA Astrophysics Data System (ADS)

    Logue, Andrew C.; Gordon, Lloyd B.

    1994-05-01

    The mockup channel tests for Space Power Experiments Aboard Rocket (SPEAR) I, SPEAR II, and SPEAR III will be examined in this paper. Specifically, high voltage results of mockup chamber tests will be compared with results of the flight hardware chamber tests and flight experiments. The authors will analyze the results obtained through the different phases of each of these programs and determine the effectiveness of the simulations that were performed in the vacuum chambers.

  14. An ultra-high vacuum chamber for scattering experiments featuring in-vacuum continuous in-plane variation of the angle between entrance and exit vacuum ports

    SciTech Connect

    Englund, Carl-Johan; Agåker, Marcus Fredriksson, Pierre; Olsson, Anders; Johansson, Niklas; Rubensson, Jan-Erik; Nordgren, Joseph

    2015-09-15

    A concept that enables in-vacuum continuous variation of the angle between two ports in one plane has been developed and implemented. The vacuum chamber allows for measuring scattering cross sections as a function of scattering angle and is intended for resonant inelastic X-ray scattering experiments. The angle between the ports can be varied in the range of 30°-150°, while the pressure change is less than 2 × 10{sup −10} mbars.

  15. Long-life micro vacuum chamber for a micromachined cryogenic cooler

    SciTech Connect

    Cao, Haishan E-mail: HaishanCao@gmail.com; Vermeer, Cristian H.; Vanapalli, Srinivas; Holland, Harry J.; Brake, H. J. Marcel ter

    2015-11-15

    Micromachined cryogenic coolers can be used for cooling small electronic devices to improve their performance. However, for reaching cryogenic temperatures, they require a very good thermal insulation from the warm environment. This is established by a vacuum space that for adequate insulation has to be maintained at a pressure of 0.01 Pa or lower. In this paper, the challenge of maintaining a vacuum chamber with a volume of 3.6 × 10{sup −5} m{sup 3} and an inner wall area of 8.1 × 10{sup −3} m{sup 2} at a pressure no higher than 0.01 Pa for five years is theoretically analyzed. The possible sources of gas, the mechanisms by which these gases enter the vacuum space and their effects on the pressure in the vacuum chamber are discussed. In a long-duration experiment with four stainless steel chambers of the above dimensions and equipped with a chemical getter, the vacuum pressures were monitored for a period of two years. In that period, the measured pressure increase stayed within 0.01 Pa. This study can be used to guide the design of long-lifetime micro vacuum chambers that operate without continuous mechanical pumping.

  16. Low-Dead-Volume Inlet for Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Naylor, Guy; Arkin, C.

    2010-01-01

    Gas introduction from near-ambient pressures to high vacuum traditionally is accomplished either by multi-stage differential pumping that allows for very rapid response, or by a capillary method that allows for a simple, single-stage introduction, but which often has a delayed response. Another means to introduce the gas sample is to use the multi-stage design with only a single stage. This is accomplished by using a very small conductance limit. The problem with this method is that a small conductance limit will amplify issues associated with dead -volume. As a result, a high -vacuum gas inlet was developed with low dead -volume, allowing the use of a very low conductance limit interface. Gas flows through the ConFlat flange at a relatively high flow rate at orders of magnitude greater than through the conductance limit. The small flow goes through a conductance limit that is a double-sided ConFlat.

  17. Low-Dead-Volume Inlet for Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Naylor, Guy; Arkin, C.

    2011-01-01

    Gas introduction from near-ambient pressures to high vacuum traditionally is accomplished either by multi-stage differential pumping that allows for very rapid response, or by a capillary method that allows for a simple, single-stage introduction, but which often has a delayed response. Another means to introduce the gas sample is to use the multi-stage design with only a single stage. This is accomplished by using a very small conductance limit. The problem with this method is that a small conductance limit will amplify issues associated with dead-volume. As a result, a high-vacuum gas inlet was developed with low dead-volume, allowing the use of a very low conductance limit interface. Gas flows through the ConFlat flange at a relatively high flow rate at orders of magnitude greater than through the conductance limit. The small flow goes through a conductance limit that is a double-sided ConFlat.

  18. RF impedance studies of a beam chamber and longitudinally slot-coupled vacuum pumping antechamber

    SciTech Connect

    Kustom, R.L.; Nicholls, G.L.; Kramer, S.L.; Khoe, T.K.; Cook, J.M.

    1987-01-01

    The storage ring vacuum chamber of the proposed 7-GeV synchrotron light source at Argonne National Laboratory is planned to have a semi-elliptical beam chamber, with a longitudinal slot coupled to an antechamber containing NEG pumping strips. Concern over the RF impedance of this complex chamber has stimulated the need to understand the limitations it will have on the beam intensity, the RF acceleration system and on the beam lifetime. Calculations using numerical EM field programs have estimated the waveguide modes of this chamber and the impedance and loss parameter for the expected 1 to 2 cm beam bunch length. The loss parameter is shown to differ little from an elliptical beam chamber without the slot and antechamber. An experimental program has begun to verify the estimates of the impedance for these complex vacuum chamber components using laboratory methods. Preliminary results are presented for the measured loss parameter for a short length of beam vacuum chamber and for other components. These results are compared with their calculated values.

  19. Design of the Aluminum Vacuum Chambers for the 3 GeV TPS Electron Storage Ring

    SciTech Connect

    Hsiung, G. Y.; Chan, C. K.; Hsueh, H. P.; Yang, T. L.; Kuan, C. K.; Chang, C. C.; Hsu, S. N.; Yang, C. Y.; Chen, C. L.; Chen, J. R.

    2007-01-19

    The conceptual design of the vacuum systems for the electron storage ring of the Taiwan Photon Source (TPS) is described. The vacuum system for the synchrotron light source not only meets the specifications of an electron beam energy of 3 GeV and a beam current at 400 mA but also provides a safety factor of {approx} 1.7 (or 3.3 GeV and 500 mA) at the upper bound. The vacuum system for the storage ring is built with consideration of the following factors: (1) Sustaining the ultrahigh vacuum (UHV), (2) Highly stable vacuum system with vibration level < 0.5 {mu}m, (3) Vacuum chambers with low impedance, (4) Thermal absorbers, and (5) Highly reliable vacuum system with least trip rate, etc. to ensure the stability of the circulating low emittance electron beam. The aluminum alloys are selected for the vacuum chambers to meet the design requirements. The concept of the design will be described.

  20. Vacuum Plasma Spray Forming of Copper Alloy Liners for Regeneratively Cooled Liquid Rocket Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank

    2003-01-01

    Vacuum plasma spray (VPS) has been demonstrated as a method to form combustion chambers from copper alloys NARloy-Z and GRCop-84. Vacuum plasma spray forming is of particular interest in the forming of CuCrNb alloys such as GRCop-84, developed by NASA s Glenn Research Center, because the alloy cannot be formed using conventional casting and forging methods. This limitation is related to the levels of chromium and niobium in the alloy, which exceed the solubility limit in copper. Until recently, the only forming process that maintained the required microstructure of CrNb intermetallics was powder metallurgy formation of a billet from powder stock, followed by extrusion. This severely limits its usefulness in structural applications, particularly the complex shapes required for combustion chamber liners. This paper discusses the techniques used to form combustion chambers from CuCrNb and NARloy-Z, which will be used in regeneratively cooled liquid rocket combustion chambers.

  1. Effect of vacuum chamber eddy current and compensation by digital feedback

    SciTech Connect

    Chung, Y.

    1992-07-27

    Measurement of the effect of the eddy current induced in the APS storage ring vacuum chamber by the storage ring sextupole magnet and its compensation using digital feedback with proportional, integral, and derivative (PID) control algorithm are presented. The magnetic field in the vacuum chamber shows strong quadrupole and sextupole components varying with frequency, in addition to significant attenuation and phase shift. Large changes in the magnet resistance and inductance were also observed. Development of a theory of digital feedback to obtain system responses and the conditions for optimal control will be described, in conduction with design of a digital filter to compensate for the eddy current effect.

  2. Vacuum measurements of the K500 cyclotron accelerator chamber

    SciTech Connect

    Mallory, M.L.; Miller, P.S.; Kuchar, J.; Hudson, E.D.

    1986-01-01

    To evaluate the effectiveness of the unique internal cryopumping system, the pressure in the K500 superconducting cyclotron was measured as a function of radius for various gas flow rates emanating from the internal PIG source. For the test, a nude ion gauge with vertical dimension less than 2.3 cm was built and mounted on the internal beam probe. The effect of magnetic field on the ion gauge reading was determined and a method of degaussing the cyclotron was devised. Data from the normal shielded ion gauge located approximately 6 m away from the median plane was correlated with the internal vacuum measurements.

  3. Performance of the beam chamber vacuum system of K = 500 cyclotron at Variable Energy Cyclotron Centre Kolkata

    SciTech Connect

    Pal, Gautam DuttaGupta, Anjan; Chakrabarti, Alok

    2014-07-15

    The beam chamber of Variable Energy Cyclotron Centre, Kolkata's K = 500 superconducting cyclotron is pumped by liquid helium cooled cryopanel with liquid nitrogen cooled radiation shield. Performance of the vacuum system was evaluated by cooling the cryopanel assembly with liquid nitrogen and liquid helium. Direct measurement of beam chamber pressure is quite difficult because of space restrictions and the presence of high magnetic field. Pressure gauges were placed away from the beam chamber. The beam chamber pressure was evaluated using a Monte Carlo simulation software for vacuum system and compared with measurements. The details of the vacuum system, measurements, and estimation of pressure of the beam chamber are described in this paper.

  4. Thermoelastic analysis of solar window of a vacuum chamber

    NASA Technical Reports Server (NTRS)

    Amba-Rao, C. L.; Soni, S. R.

    1975-01-01

    It has been noted during space simulation test programs that the chamber penetration window becomes the limiting factor as the solar intensity increases. The temperature at the center of the window normally attains a level of 550 C, while the edge temperature remains at about 35 C. The stresses produced by this thermal gradient combined with the atmospheric pressure are studied within the framework of classical theory of elasticity. The solution for the problem is obtained by solving the static uncoupled thermoelastic equations for a circular blank, subjected to nonuniform heat on one face, by introduction of two auxiliary variables. The displacements are expressed in terms of Bessel functions and parameters of interest are computed at various mesh points of the window. The maximum principal stresses thus obtained show that even with steep temperature gradient, the safety factor is acceptable.

  5. Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load

    NASA Technical Reports Server (NTRS)

    Garcia, Sam; Meagher, Daniel; Linza, Robert; Saheli, Fariborz; Vargas, Gerardo; Lauterbach, John; Reis, Carl; Ganni, Venkatarao (Rao); Homan, Jonathan

    2008-01-01

    NASA s Johnson Space Center (JSC) Building 32 houses two large thermal-vacuum chambers (Chamber A and Chamber B). Within these chambers are liquid nitrogen shrouds to provide a thermal environment and helium panels which operate at 20K to provide cryopumping. Some amount of air leakage into the chambers during tests is inevitable. This causes "air fouling" of the helium panel surfaces due to the components of the air that adhere to the panels. The air fouling causes the emittance of the helium panels to increase during tests. The increase in helium panel emittance increases the heat load on the helium refrigerator that supplies the 20K helium for those panels. Planning for thermal-vacuum tests should account for this increase to make sure that the helium refrigerator capacity will not be exceeded over the duration of a test. During a recent test conducted in Chamber B a known-size air leak was introduced to the chamber. Emittance change of the helium panels and the affect on the helium refrigerator was characterized. A description of the test and the results will be presented.

  6. Reception and study of lunar surface material in inert gas medium. [considering laboratory vacuum receiving chamber

    NASA Technical Reports Server (NTRS)

    Surkov, Y. A.; Rudnitskiy, Y. M.; Glotov, V. A.

    1974-01-01

    The reception and study of lunar material returned by the Luna 16 space station is described. The layout of a vacuum receiving chamber for working with material in a helium atmosphere is examined along with the main operations involved in extracting the material from the ampule and drill.

  7. Modelling of e-cloud build-up in grooved vacuum chambers usingPOSINST

    SciTech Connect

    Venturini, Marco; Celata, C.; Furman, Miguel; Vay, Jean-Luc; Pivi, Mauro

    2007-06-29

    Use of grooved vacuum chambers have been suggested as a wayto limitelectron cloud accumulation in the ILC-DR. We report onsimulations carried out using an augmented version of POSINST, accountingfor e-cloud dynamics in the presence of grooves, and make contact withprevious estimates of an effective secondary electron yield for groovedsurfaces.

  8. Modeling of E-Cloud Build-Up in Grooved Vacuum Chambers using POSINST

    SciTech Connect

    Furman, Miguel A.; Vay, Jean-Luc; Venturini, M.; Pivi, M.T.F.; /SLAC

    2008-01-23

    Use of grooved vacuum chambers have been suggested as a way to limit electron cloud accumulation in the ILCDR. We report on simulations carried out using an augmented version of POSINST, accounting for e-cloud dynamics in the presence of grooves, and make contact with previous estimates of an effective secondary electron yield for grooved surfaces.

  9. PEP-II vacuum system - joining SS flanges to copper beam chambers

    SciTech Connect

    Fetzko, S.; Hoyt, E.; Cummings, U.

    1994-06-01

    Various methods of joining stainless steel flanges to the copper PEP-II high-energy ring vacuum chambers was investigated with regard to metallurgical soundness, reliability, complexity, and cost. The most promising method appears to be direct electron-beam welding.

  10. Study on thermally induced vibration of flexible boom in various thermal environments of vacuum chamber

    NASA Astrophysics Data System (ADS)

    Kong, Changduk; Oh, Kyung-Won; Park, Hyun-Bum; Sugiyama, Y.

    2005-02-01

    In order to simulate the thermally-induced vibration phenomenon of the flexible thin boom structure of the spacecraft such as the thin solar panel and the flexible cantilever with the attached tip mass in space, the thermally-induced vibration including thermal flutter of the flexible thin boom with the concentrated tip mass was experimentally investigated at various thermal environments using a heat lamp and both vacuum and air condition using the vacuum chamber. In this experimental study, divergence speed, natural frequency and thermal strains of the thermally-induced vibration were comparatively evaluated at various thermal environment conditions. Finally the thermally-induced vibration of the flexible boom structure of the earth orbit satellite in solar radiation environment from the earth eclipse region including umbra and penumbra was simulated using the vacuum chamber and power control of the heating lamp.

  11. Determining Temperature Differential to Prevent Hardware Cross-Contamination in a Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Hughes, David

    2013-01-01

    When contamination-sensitive hardware must be tested in a thermal vacuum chamber, cross-contamination from other hardware present in the chamber, or residue from previous tests, becomes a concern. Typical mitigation strategies involve maintaining the temperature of the critical item above that of other hardware elements at the end of the test. A formula for relating the pumping speed of a chamber, the surface area of contamination sources, and the temperatures of the chamber, source, and contamination-sensitive items has been developed. The formula allows the determination of a temperature threshold about which contamination will not condense on the sensitive items. It defines a parameter alpha that is the fraction given by (contaminant source area)/[chamber pumping speed (time under vacuum) 0.5]. If this parameter is less than 10(exp -6), cross-contamination from common spacecraft material will not occur when the sensitive hardware is at the same temperature as the source of contamination (The chamber is isothermal within 5 C.). Knowing when it becomes safe to have the hardware isothermal permits faster and easier thermal transitions when compared with maintaining an arbitrary temperature differential between parts. Furthermore, the standard temperature differential may not be adequate under some conditions (alpha>10(exp -4)).

  12. A new approach for performing contamination control bakeouts in JPL thermal vacuum test chambers

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R.; Taylor, Daniel M.; Lane, Robert W.; Cortez, Maximo G.; Anderson, Mark R.

    1992-01-01

    Contamination control requirements for the Wide Field/Planetary Camera II (WF/PC II) are necessarily stringent to protect against post-launch contamination of the sensitive optical surfaces, particularly the cold charge coupled device (CCD) imaging surfaces. Typically, thermal vacuum test chambers have employed a liquid nitrogen (LN2) cold trap to collect outgassed contaminants. This approach has the disadvantage of risking recontamination of the test article from shroud offgassing during post-test warmup of the chamber or from any shroud warming of even a few degrees during the bakeout process. By using an enclave, essentially a chamber within a chamber, configured concentrically and internally within an LN2 shroud, a method was developed, based on a design concept by Taylor, for preventing recontamination of test articles during bakeouts and subsequent post-test warmup of the vacuum chamber. Enclaves for testing WF/PC II components were designed and fabricated, then installed in three of JPL's Environmental Test Lab chambers. The design concepts, operating procedures, and test results of this development are discussed.

  13. Development of fast heating electron beam annealing setup for ultra high vacuum chamber

    NASA Astrophysics Data System (ADS)

    Das, Sadhan Chandra; Majumdar, Abhijit; Katiyal, Sumant; Shripathi, T.; Hippler, R.

    2014-02-01

    We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 °C with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (˜10-6 mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 °C of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C.

  14. Development of fast heating electron beam annealing setup for ultra high vacuum chamber

    SciTech Connect

    Das, Sadhan Chandra; Majumdar, Abhijit E-mail: majumdar@uni-greifswald.de; Hippler, R.; Katiyal, Sumant; Shripathi, T.

    2014-02-15

    We report the design and development of a simple, electrically low powered and fast heating versatile electron beam annealing setup (up to 1000 °C) working with ultra high vacuum (UHV) chamber for annealing thin films and multilayer structures. The important features of the system are constant temperature control in UHV conditions for the temperature range from room temperature to 1000 ºC with sufficient power of 330 W, at constant vacuum during annealing treatment. It takes approximately 6 min to reach 1000 °C from room temperature (∼10{sup −6} mbar) and 45 min to cool down without any extra cooling. The annealing setup consists of a UHV chamber, sample holder, heating arrangement mounted on suitable UHV electrical feed-through and electronic control and feedback systems to control the temperature within ±1 ºC of set value. The outside of the vacuum chamber is cooled by cold air of 20 °C of air conditioning machine used for the laboratory, so that chamber temperature does not go beyond 50 °C when target temperature is maximum. The probability of surface oxidation or surface contamination during annealing is examined by means of x-ray photoelectron spectroscopy of virgin Cu sample annealed at 1000 °C.

  15. Design of large vacuum chamber for VEC superconducting cyclotron beam line switching magnet

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Sumantra; Nandi, Chinmoy; Gayen, Subhasis; Roy, Suvadeep; Mishra, Santosh Kumar; Ramrao Bajirao, Sanjay; Pal, Gautam; Mallik, C.

    2012-11-01

    VEC K500 superconducting cyclotron will be used to accelerate heavy ion. The accelerated beam will be transported to different beam halls by using large switching magnets. The vacuum chamber for the switching magnet is around 1000 mm long. It has a height of 85 mm and width varying from 100 mm to 360 mm. The material for the chamber has been chosen as SS304.The material for the vacuum chamber for the switching magnet has been chosen as SS304. Design of the vessel was done as per ASME Boiler and Pressure Vessel Code, Section VIII, Division 1. It was observed that primary stress values exceed the allowable limit. Since, the magnet was already designed with a fixed pole gap; increase of the vacuum chamber plate thickness restricts the space for beam transport. Design was optimized using stress analysis software ANSYS. Analysis was started using plate thickness of 4 mm. The stress was found higher than the allowable level. The analysis was repeated by increasing plate thickness to 6 mm, resulting in the reduction of stress level below the allowable level. In order to reduce the stress concentration due to sharp bend, chamfering was done at the corner, where the stress level was higher. The thickness of the plate at the corner was increased from 6 mm to 10 mm. These measures resulted in reduction of localized stress.

  16. Open loop, auto reversing liquid nitrogen circulation thermal system for thermo vacuum chamber

    NASA Astrophysics Data System (ADS)

    Naidu, M. C. A.; Nolakha, Dinesh; Saharkar, B. S.; Kavani, K. M.; Patel, D. R.

    2012-11-01

    In a thermo vacuum chamber, attaining and controlling low and high temperatures (-100 Deg. C to +120 Deg. C) is a very important task. This paper describes the development of "Open loop, auto reversing liquid nitrogen based thermal system". System specifications, features, open loop auto reversing system, liquid nitrogen flow paths etc. are discussed in this paper. This thermal system consists of solenoid operated cryogenic valves, double embossed thermal plate (shroud), heating elements, temperature sensors and PLC. Bulky items like blowers, heating chambers, liquid nitrogen injection chambers, huge pipe lines and valves were not used. This entire thermal system is very simple to operate and PLC based, fully auto system with auto tuned to given set temperatures. This system requires a very nominal amount of liquid nitrogen (approx. 80 liters / hour) while conducting thermo vacuum tests. This system was integrated to 1.2m dia thermo vacuum chamber, as a part of its augmentation, to conduct extreme temperature cycling tests on passive antenna reflectors of satellites.

  17. An ultra-high-vacuum multiple grating chamber and scan drive with improved grating change

    SciTech Connect

    Hulbert, S.L.; Holly, D.J.; Middleton, F.H.; Wallace, D.J.; Wisconsin Univ., Stoughton, WI . Physical Sciences Lab.; Wisconsin Univ., Stoughton, WI . Synchrotron Radiation Center)

    1989-01-01

    We describe a new grating chamber and scan drive which has been designed, built, and tested by Physical Sciences Laboratory of the University of Wisconsin for the new high flux, high-resolution spectroscopy branch line of the TOK hybrid wiggler/undulator on the NSLS VUV ring. The chamber will contain spherical gratings to be used in the Spherical Grating Monochromator (SGM) configuration introduced by Chen and Sette. The grating chamber houses five 180 mm {times} 35 mm {times} 30 mm gratings capable of scanning a range of 12{degree} ({minus}14{degree} to +8{degree} with respect to the incoming beam direction) for VUV and soft X-ray diffraction. The gratings can be switched and precisely indexed while under ultra-high vacuum (UHV) at any scan angle and are mechanically isolated from the vacuum chamber to prevent inaccuracies due to chamber distortions. The gratings can separately be adjusted for height, yaw, pitch, and roll, with the latter three performed while in vacuo. The scan drive provides a resolution of 0.03 arc sec with linearity over the 12{degree} range of {approx}1.5 arc sec and absolute reproducibility of 1 arc sec. 5 refs., 5 figs.

  18. A drift chamber with a new type of straws for operation in vacuum

    NASA Astrophysics Data System (ADS)

    Azorskiy, N.; Glonti, L.; Gusakov, Yu.; Elsha, V.; Enik, T.; Kakurin, S.; Kekelidze, V.; Kislov, E.; Kolesnikov, A.; Madigozhin, D.; Movchan, S.; Polenkevich, I.; Potrebenikov, Yu.; Samsonov, V.; Shkarovskiy, S.; Sotnikov, S.; Zinchenko, A.; Danielsson, H.; Bendotti, J.; Degrange, J.; Dixon, N.; Lichard, P.; Morant, J.; Palladino, V.; Gomez, F. Perez; Ruggiero, G.; Vergain, M.

    2016-07-01

    A 2150×2150 mm2 registration area drift chamber capable of working in vacuum is presented. Thin-wall tubes (straws) of a new type are used in the chamber. A large share of these 9.80 mm diameter drift tubes are made in Dubna from metalized 36 μm Mylar film welded along the generatrix using an ultrasonic welding machine created at JINR. The main features of the chamber and some characteristics of the drift tubes are described. Four such chambers with the X, Y, U, V coordinates each, containing 7168 straws in total, are designed and produced at JINR and CERN. They are installed in the vacuum volume of the NA62 setup in order to study the ultra-rare decay K+ →π+ vv bar and to search for and study rare meson decays. In autumn 2014 the chambers were used for the first time for the data taking in the experimental run of the NA62 at CERN's SPS.

  19. Pressure distribution along the AGS vacuum chambers with new types of pump out conduits

    SciTech Connect

    Nayak, S.; Mapes, M.; Smart, L.; Weiss, D.

    2015-10-28

    The AGS HEBT and ring vacuum system is monitored by the discharge current of the magnet ion pumps, which is proportional to the pressure at the inlet port of these ion pumps. The discharge current is measured and suitably calibrated to indicate the ion pump pressure. In order to calculate the vacuum chamber pressure from the ion pump pressure, a detailed analysis is essential to compute their difference in different scenarios. Such analysis has been carried out numerically in the past for the system with the older type of pump out conduits, and similar analysis using FEM in ANSYS is presented in this paper with the newer type of pump out conduit.

  20. Coupling impedance of a long slot and an array of slots in a circular vacuum chamber

    SciTech Connect

    Stupakov, G.V.

    1995-06-01

    We find the real part of the longitudinal impedance for both a small hole and a long slot in a beam vacuum chamber with a circular cross section. The slot can be arbitrarily long; the only requirement on the dimensions of the slots is that its width be much smaller than c/w. Regular array of N slots periodically distributed along the pipe is also considered.

  1. Compensation for the eddy current effect in the APS storage ring vacuum chamber

    SciTech Connect

    Chung, Y.

    1990-05-30

    The amplitude attenuation and the phase shift of the correction magnet field inside the APS storage ring vacuum chamber due to the eddy current effect were measured. A circuit to compensate for this effect was then inserted between the signal source and the magnet power supply. The amplitude was restored with an error of less than 20% of the source signal amplitude and the phase shift was reduced from 80{degrees} to 12{degrees} at 10 Hz.

  2. Flow chamber

    DOEpatents

    Morozov, Victor

    2011-01-18

    A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

  3. Qualification of Target Chamber Vacuum Systems Cleanliness using Sol-Gel Coatings

    SciTech Connect

    Miller, P; Stowers, I F; Ertel, J R

    2006-01-03

    This document defines the procedure necessary to qualify the airborne molecular cleanliness (AMC) of vacuum systems (enclosures or large components) that are placed within the National Ignition Facility (NIF) target chamber or are attached to it and communicate with it during vacuum operation. This test is specific to the NIF target chamber because the allowable time dependent rate of rise in the pore filling of a sol-gel coated SAW sensor is based on some nominal change-out time for the disposable debris shields. These debris shields will be sol-gel coated and thus they represent a means of ''pumping'' AMCs from the target chamber. The debris shield pumping rate sets the allowable change in pore filling with time specified in the test procedure. This document describes a two-part procedure that provides both a static measurement of sol-gel pore filling at the end of a 48-hour test period and a dynamic record of pore-filling measured throughout the test period. Successful qualification of a vacuum system requires that both the static and dynamic measurements meet the criteria set forth in Section 7 of this document.

  4. The Design, Construction and Testing of a Multipole Wiggler Magnet Titanium Vacuum Chamber for the SRS.

    NASA Astrophysics Data System (ADS)

    Bliss, Neil; Dawson, Cheryl

    1997-05-01

    An upgrade to the SRS is planned, which will provide high quality X-rays to upto four new experimental stations, on two new beamlines. These X-rays will originate in two new 2T multipole wiggler (MPW) insertion devices. The insertion devices are a hybrid design consisting of Neodymium-Iron-Boron permanent magnets and Vanadium Permendur pole pieces. In order to achieve the high on-axis field strength of the MPW and reduce the volume of permanent magnet material, a minimum amount of vacuum chamber material is required between the electron beam stay clear aperture and the poles of the MPW. Careful consideration has been given to the design, material selection and construction technique for the vacuum chamber to achieve a 1 mm wall thickness and 0.3 mm flatness tolerance over the nine pole face areas. Titanium alloy Ti-6Al-4V has been chosen in preference to more conventional ultra high vacuum chamber materials and a prototype has been constructed and tested.

  5. Using In-situ Cryogenic Radiometers to Measure the Performance of a Large Thermal Vacuum Chamber

    NASA Astrophysics Data System (ADS)

    DiPirro, Michael; Canavan, Edgar; Tuttle, James; Havey, Keith; Huguet, Jesse; Ousley, Wes; Shirron, Peter; Hait, Thomas

    2015-12-01

    The James Webb Space Telescope will operate in space at temperatures lower than 50 K. To test the major parts of the telescope and instruments on the ground requires a very large thermal vacuum chamber with a helium-cooled shroud operating below 20 K. This chamber and shroud are being subjected to a series of 4 preliminary tests to characterize the chamber and the ground support equipment before the telescope and instruments are tested. We have made measurements in the first of these preliminary tests using simple radiometers, which are located in the chamber and are pointed at various locations and items of interest within the chamber. The radiometers, which have been previously described[1], consist of a Cernox thermometer attached to an absorber suspended behind a Winston cone with an acceptance half-angle of 11 degrees. 9 of these radiometers were anchored to the chamber at temperatures between 17 and 25 K and were able to resolve 2 mW over an area of one m2. This level of sensitivity corresponds to a 60 K blackbody, which spans the radiometer field of view, changing in temperature by 0.04 K. The results of this test and plans for future tests will be described.

  6. Analyzing the contents of residual and plasma-supporting gases inside a vacuum deposition unit chamber

    NASA Astrophysics Data System (ADS)

    Mikheev, A. Ye; Kharlamov, V. A.; Kruchek, S. D.; Cherniatina, A. A.; Khomenko, I. I.

    2015-01-01

    The paper describes a quadruple mass-spectrometer method, which is used to analyze the content of residual gas in a vacuum chamber of the ARM NTM (Automatised Working Area) ion-plasma unit. This unit is used to perfect the magnetron deposition process for coating radio-reflecting surfaces. The intake of pure argon into the chamber revealed up to 0.3 % of impurities in the plasma-supporting gas, including 0.02 % of water and oxygen. A significant presence of hydrocarbon gases is explained by the presence of solvents sorbed in rubber washers, joints of internal equipment, and other components inside the chamber. In order to decrease the level of impurities in the plasmasupporting atmosphere inside the chamber and improve the composition and properties of the coatings, it is necessary to take additional measures to cleanse and degas the surface of the chamber from condensation products and hydrocarbon compounds. To provide a minimal level of impurities in the coated surfaces it is vital to clean and degas the surfaces of the chamber, removing residual moisture and hydrocarbon compounds.

  7. Fatigue induced cracking in aluminum LN-2 shroud of 39 foot vacuum chamber

    NASA Technical Reports Server (NTRS)

    Edwards, A. A.

    1984-01-01

    Fourteen years after completion of Ford's 39-foot space simulation chamber, leaks began to appear in its LN2 shroud. Although the shroud had been tight since its acceptance, cracks appeared in 1983 in some of the field welds of the one inch tubes which interconnect the LN2 panels. The resulting leaks were large enough to prevent pump down to high vacuum and could be heard easily when the chamber was at ambient conditions. New cracks appeared during each thermal cycle making it impossible to utilize the chamber for thermal vacuum testing. The analysis presented here implies that many, if not all, of the aluminum LN2 shrouds now in use may be in various stages of fatigue failure. The probability is high that fatigue cracks are working through the aluminum tubing in heat-affected zones of some field welds. The cracks may not be apparent yet, but after the shroud has experienced a certain number of thermal cycles these cracks will work through the material and become serious leaks. Fortunately, appropriate planning, analysis, and checking can, with a relatively small expenditure of money, help to avoid large and unexpected shroud failures and keep the chamber operational as long as it is needed.

  8. Outgassing properties of the spallation neutron source ring vacuum chambers coated with titanium nitride

    NASA Astrophysics Data System (ADS)

    He, P.; Hseuh, H. C.; Mapes, M.; Todd, R.; Weiss, D.; Wilson, D.

    2004-05-01

    The stainless steel vacuum chambers of the 248 m accumulator ring of the Spallation Neutron Source are to be coated with ~100 nm of titanium nitride (TiN). This is to minimize the secondary electron yield from the chamber wall, and thus avoid the so-called e-p instability caused by electron multipacting as observed in a few high-intensity proton storage rings. Reports in the literature suggest that a TiN coating, by acting as a hydrogen permeation barrier, may also reduce the ultimate outgassing rate. The outgassing rate of TiN coated chambers deposited at various sputtering pressures was measured and compared to uncoated chambers, both with and without 250 °C in situ bake. Some coated chambers were subjected to glow discharge treatment (GDT). It was found that the surface roughness, analyzed with a scanning electron microscope, depends on the deposition pressure and is also influenced by GDT. The outgassing rate varies as a function of the surface roughness of the TiN layer, with rougher coatings more hydroscopic in nature. The in situ postbake outgassing rate was reduced ~30% for a chamber coated with TiN at low pressure and subsequently subjected to GDT, thus giving evidence that the TiN layer acts as a permeation barrier to hydrogen diffusion. It was also found that a 450 °C vacuum degas reduced the hydrogen outgassing rate one order of magnitude, although the amount of reduction does not agree with the value predicted by standard diffusion equations. .

  9. Mimicking Mars: A vacuum simulation chamber for testing environmental instrumentation for Mars exploration

    SciTech Connect

    Sobrado, J. M. Martín-Soler, J.; Martín-Gago, J. A.

    2014-03-15

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10{sup −6} mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

  10. Mimicking Mars: a vacuum simulation chamber for testing environmental instrumentation for Mars exploration.

    PubMed

    Sobrado, J M; Martín-Soler, J; Martín-Gago, J A

    2014-03-01

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10(-6) mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated. PMID:24689624

  11. Vacuum Plasma Spray of CuCrNb Alloy for Advanced Liquid - Fuel Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank

    2000-01-01

    The copper-8 atomic percent chromium-4 atomic percent niobium (CuCrNb) alloy was developed by Glenn Research Center (formally Lewis Research Center) as an improved alloy for combustion chamber liners. In comparison to NARloy-Z, the baseline (as in Space Shuttle Main Engine) alloy for such liners, CuCrNb demonstrates mechanical and thermophysical properties equivalent to NARloy-Z, but at temperatures 100 C to 150 C (180 F to 270 F) higher. Anticipated materials related benefits include decreasing the thrust cell liner weight 5% to 20%, increasing the service life at least two fold over current combustion chamber design, and increasing the safety margins available to designers. By adding an oxidation and thermal barrier coating to the liner, the combustion chamber can operate at even higher temperatures. For all these benefits, however, this alloy cannot be formed using conventional casting and forging methods because of the levels of chromium and niobium, which exceed their solubility limit in copper. Until recently, the only forming process that maintains the required microstructure of CrNb intermetallics is powder metallurgy formation of a billet from powder stock, followed by extrusion. This severely limits its usefulness in structural applications, particularly the complex shapes required for combustion chamber liners. Vacuum plasma spray (VPS) has been demonstrated as a method to form structural articles including small combustion chambers from the CuCrNb alloy. In addition, an oxidation and thermal barrier layer can be formed integrally on the hot wall of the liner that improve performance and extend service life. This paper discusses the metallurgy and thermomechanical properties of VPS formed CuCrNb versus the baseline powder metallurgy process, and the manufacturing of small combustion chamber liners at Marshall Space Flight Center using the VPS process. The benefits to advanced propulsion initiatives of using VPS to fabricate combustion chamber liners

  12. Ultrahigh-vacuum chamber equipped with a reaction cell for studying liquid-phase catalytic reactions

    NASA Astrophysics Data System (ADS)

    Gardin, Denis E.; Somorjai, Gabor A.

    1993-05-01

    We describe the construction and operation of a liquid-phase reaction cell designed in our laboratory that is attached to an ultrahigh-vacuum (UHV) chamber equipped with the traditional surface science techniques for structure and composition analysis. The sample surface can be prepared and characterized in the UHV chamber prior to transfer in the liquid-phase reaction cell. The transfer has been designed so that there is no loss of the UHV chamber vacuum integrity, as few parts as possible come into contact with the liquid, the surface stays clean during the transfer. The liquid-phase reaction cell itself is designed to study liquid-phase hydrogenation reactions at pressures up to 2 atm and temperatures up to 70 °C. A 1-mm-diam liquid jet with a velocity up to 6 m/s is produced by a gear pump that is incident on the sample surface to allow good mass transfer at the liquid-solid interface. The progress of the reaction is followed by gas chromatography. We report the reaction rate data for the hydrogenation of cyclohexene on a platinum foil.

  13. Ultrahigh-vacuum chamber equipped with a reaction cell for studying liquid-phase catalytic reactions

    SciTech Connect

    Gardin, D.E.; Somorjai, G.A. )

    1993-05-01

    We describe the construction and operation of a liquid-phase reaction cell designed in our laboratory that is attached to an ultrahigh-vacuum (UHV) chamber equipped with the traditional surface science techniques for structure and composition analysis. The sample surface can be prepared and characterized in the UHV chamber prior to transfer in the liquid-phase reaction cell. The transfer has been designed so that there is no loss of the UHV chamber vacuum integrity, as few parts as possible come into contact with the liquid, the surface stays clean during the transfer. The liquid-phase reaction cell itself is designed to study liquid-phase hydrogenation reactions at pressures up to 2 atm and temperatures up to 70 [degree]C. A 1-mm-diam liquid jet with a velocity up to 6 m/s is produced by a gear pump that is incident on the sample surface to allow good mass transfer at the liquid-solid interface. The progress of the reaction is followed by gas chromatography. We report the reaction rate data for the hydrogenation of cyclohexene on a platinum foil.

  14. The U.S. Lab is placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    With the lid of the three-story vacuum chamber in place, a worker on top checks release of the cables. Inside the chamber is the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  15. A Large High Vacuum Reaction Chamber for Nuclear Physics Research at VECC, Kolkata

    NASA Astrophysics Data System (ADS)

    Kundu, S.; Bhattacharya, S.; Meena, J. K.; Ghosh, T. K.; Bhattacharjee, T.; Mukhopadhyay, P.; Bhattacharya, C.; Rana, T. K.; Banerjee, K.; Mukherjee, G.; Banerjee, S. R.; Bandyopadhyay, D. L.; Ahammed, M.; Bhattacharya, P.

    2012-11-01

    A large, segmented, horizontal axis, reaction chamber (SHARC) has recently been fabricated, installed and integrated with the beam line in the VECC superconducting cyclotron (SCC) experimental area. It is a cylindrical, three segment, stainless steel chamber of length 2.2 m, diameter 1 m. Two pairs of parallel rails have been provided internally for placement of the target assembly and detector systems within the chamber. The whole target assembly can be placed anywhere on the rail to facilitate optimum flight path. The nominal vacuum of ~1×10-7 mbar has been obtained in ~8 hrs by means of two turbo molecular (1000 l/s) and two cryo pumps (2500 l/s) backed by mechanical pumps. The whole vacuum system as well as the target positioning (vertical and rotational movements) operations are fully automated with manual override option; both are monitored and controlled locally as well as remotely through the local and remote control units providing real time status display.

  16. Preparation of a Frozen Regolith Simulant Bed for ISRU Component Testing in a Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Klenhenz, Julie; Linne, Diane

    2013-01-01

    In-Situ Resource Utilization (ISRU) systems and components have undergone extensive laboratory and field tests to expose hardware to relevant soil environments. The next step is to combine these soil environments with relevant pressure and temperature conditions. Previous testing has demonstrated how to incorporate large bins of unconsolidated lunar regolith into sufficiently sized vacuum chambers. In order to create appropriate depth dependent soil characteristics that are needed to test drilling operations for the lunar surface, the regolith simulant bed must by properly compacted and frozen. While small cryogenic simulant beds have been created for laboratory tests, this scale effort will allow testing of a full 1m drill which has been developed for a potential lunar prospector mission. Compacted bulk densities were measured at various moisture contents for GRC-3 and Chenobi regolith simulants. Vibrational compaction methods were compared with the previously used hammer compaction, or "Proctor", method. All testing was done per ASTM standard methods. A full 6.13 m3 simulant bed with 6 percent moisture by weight was prepared, compacted in layers, and frozen in a commercial freezer. Temperature and desiccation data was collected to determine logistics for preparation and transport of the simulant bed for thermal vacuum testing. Once in the vacuum facility, the simulant bed will be cryogenically frozen with liquid nitrogen. These cryogenic vacuum tests are underway, but results will not be included in this manuscript.

  17. Sealing system for a movable vacuum chamber of a charged particle beam machine

    SciTech Connect

    Anderl, P.; Kappelsberger, E.; Konig, D.; Monch, C.; Scheffels, W.; Steigerwald, K.

    1982-11-09

    A system for sealing the working vacuum chamber of a charged particle beam machine which is movable with respect to a workpiece is disclosed. The system includes a housing with a central compartment having wire-shaped elements urged against the workpiece to provide a seal therebetween, and lateral compartments, each having a packing of sealing material which is biased against the workpiece surface of a spring arrangement. Rollers and a flexible lip seal arrangement having a flexible sheath of synthetic rubber are also disclosed.

  18. High-Speed Automated Tester for Vacuum Chamber Feedthrough Connectors and Cables

    NASA Technical Reports Server (NTRS)

    Swope, Robert H.; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Goddard Space Flight Center's thermal vacuum laboratory has developed a high-speed automated system for testing the integrity of 37-pin MIL-C-5015 cylindrical electrical feedthrough connectors used on penetration plates of thermal vacuum chambers. The system consists of a desktop PC driving a data acquisition front end. The latter measures the resistance through each pin of the connector and the resistance from each pin to all other pins and the connector shell. In addition to identifying unacceptable feedthroughs, the system is also used for testing cables. In the special case of Type T thermocouples (used almost exclusively at the lab), the difference in resistance between the copper and constantan wires provides positive proof of accidentally reversed connector wiring. Data acquisition time to completely test a cable or feedthrough connector is less than thirty seconds. The system provides a hardcopy printout of the resistance readings. Connectors or cables with fewer wires are tested using simple adapter cables. Initial tests indicate that the performance of a given feedthrough connector can be predicted on the basis of measured resistance readings, reducing ongoing cost of connector replacement. The opportunity to positively certify the integrity of cables, cable connectors and feedthroughs before the start of a thermal vacuum test minimizes the likelihood of a circuit problem that would require returning the chamber to ambient conditions for repair. This system has two principal advantages for the Goddard thermal vacuum laboratory. Its only significant cost was the labor to fabricate the test cable and shorting cable -- about 40 man-hours total. The system was built around a computer and data acquisition unit that were already on hand. The second advantage is that it very quickly tests both of the parameters that are essential.

  19. CSR IMPEDANCE DUE TO A BEND MAGNET OF FINITE LENGTH WITH A VACUUM CHAMBER OF RECTANGULAR CROSS SECTION

    SciTech Connect

    Stupakov, G.; Kotelnikov, I.A.; /Novosibirsk State U.

    2009-06-05

    We study the impedance due to coherent synchrotron radiation (CSR) generated by a short bunch of charged particles passing through a dipole magnet of finite length in a vacuum chamber of a given cross section. Our method represents a further development of the previous studies: we decompose the electromagnetic field of the beam over the eigenmodes of the toroidal chamber and derive a system of equations for the expansion coefficients in the series. We illustrate our general method by calculating the CSR impedance of a beam moving in a toroidal vacuum chamber of rectangular cross section.

  20. Conceptual Design of Vacuum Chamber for testing of high heat flux components using electron beam as a source

    NASA Astrophysics Data System (ADS)

    Khan, M. S.; Swamy, Rajamannar; Khirwadkar, S. S.; Divertors Division, Prototype

    2012-11-01

    A conceptual design of vacuum chamber is proposed to study the thermal response of high heat flux components under energy depositions of the magnitude and durations expected in plasma fusion devices. It is equipped with high power electron beam with maximum beam power of 200 KW mounted in a stationary horizontal position from back side of the chamber. The electron beam is used as a heat source to evaluate the heat removal capacity, material performance under thermal loads & stresses, thermal fatigue etc on actively cooled mock - ups which are mounted on a flange system which is the front side door of the chamber. The tests mock - ups are connected to a high pressure high temperature water circulation system (HPHT-WCS) operated over a wide range of conditions. The vacuum chamber consists of different ports at different angles to view the mock -up surface available for mock -up diagnostics. The vacuum chamber is pumped with different pumps mounted on side ports of the chamber. The chamber is shielded from X - rays which are generated inside the chamber when high-energy electrons are incident on the mock-up. The design includes development of a conceptual design with theoretical calculations and CAD modelling of the system using CATIA V5. These CAD models give an outline on the complete geometry of HHF test chamber, fabrication challenges and safety issues. FEA analysis of the system has been performed to check the structural integrity when the system is subjected to structural & thermal loads.

  1. All-Metal Magnetic RAM

    NASA Technical Reports Server (NTRS)

    Torok, E. J.; Spitzer, R.

    2000-01-01

    The factors that enter into the development of an all-metal, nonvolatile magnetic RAM, in which multilayer giant magnetoresistive films are used for all functions - storage, readout, and support electronics - are described. Four significant characteristics are expected to favor all-metal over hybrid magnetic RAM. First, silicon-technology fabrication requires a large number of masking steps, including complex ones such as ion implantation. Conversely, all-metal technology is inherently simple: fewer masking steps, no doping, scaling to lithographic limits, very little operating power. Second, the all-metal footprint is significantly smaller than the hybrid one. Third, an all-metal RAM is expected to be able to be miniaturized to lithographic limits; miniaturization of hybrid magnetic RAMs is likely to be limited by the semiconductor circuitry. Finally, semiconductor processing and magnetic processing in MRAM are done separately because the former requires high temperatures, whereas magnetic fabrication is a low-temperature process. By contrast, because both GMR electronics and the memory elements are made of the same materials, the two major components are deposited and patterned concurrently on the same substrate.

  2. The U.S. Lab is placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A worker in the Operations and Checkout Building checks the placement of the lid on the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  3. The U.S. Lab placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In the Operations and Checkout Building, the U.S. Lab, a component of the International Space Station, is lowered into a three-story vacuum chamber. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  4. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The U.S. Lab, a component of the International Space Station, is lifted off the floor of the Operations and Checkout Building in order to be placed inside the vacuum chamber in the building. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  5. The U.S. Lab is placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    - An overhead crane moves the lid over the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  6. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The U.S. Lab, a component of the International Space Station, is centered over the three-story vacuum chamber in which the Lab will be placed. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  7. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    - The U.S. Lab, a component of the International Space Station, is lifted above the three-story vacuum chamber into which the Lab will be placed. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  8. The U.S. Lab is placed in vacuum chamber for leak test

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Workers in the Operations and Checkout Building check the placement of the lid on the vacuum chamber containing the U.S. Lab, a component of the International Space Station. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  9. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The U.S. Lab, a component of the International Space Station, is moved toward the center over the three- story vacuum chamber in which the Lab will be placed. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  10. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A worker checks the cable fittings on the U.S. Lab, a component of the International Space Station, before it is lifted and placed inside the vacuum chamber in the Operations and Checkout Building. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber for a leak test. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  11. Development of a two-color projection system for the KHILS Vacuum Cold Chamber (KVACC)

    NASA Astrophysics Data System (ADS)

    Flynn, David S.; Marlow, Steven A.; Kircher, James R.; Glattke, Eric W.; Murrer, Robert Lee; Weir, John S.

    2000-07-01

    The KHILS Vacuum Cold Chamber (KVACC) was developed to provide the capability of performing hardware-in-the-loop testing of infrared seekers requiring scenes involving cold backgrounds. Being able to project cold backgrounds enables the projector to simulate high-altitude exoatmospheric engagements. Previous tests with the KVACC projection system have used only one resistive-array projection device. In order to realistically stimulate a 2-color seeker, it is necessary to project in two, independently controlled IR bands. Missile interceptors commonly use two or more colors; thus, a 2-color projection capability has been developed for the KVACC system. The 2- color projection capability is being accomplished by optically combining two Phase 3 WISP arrays with a dichroic beam combiner. Both WISP arrays are cooled to user-selected temperatures ranging from ambient temperature to below 150 K. In order to test the projection system, a special-purpose camera has also been developed. The camera is designed to operate inside the vacuum chamber. It has a cooled, all- reflective broadband optical system to enable the measurement of low radiance levels in the 3 - 12 micrometer spectrum. Camera upgrades later this year will allow measurements in two independent wavebands. Both the camera and the projector will be described in this paper.

  12. Ellipsometry with polarisation analysis at cryogenic temperatures inside a vacuum chamber

    SciTech Connect

    Bauer, S.; Grees, B.; Spitzer, D.; Beck, M.; Bottesch, R.; Ortjohann, H.-W.; Schäfer, T.; Wegmann, A.; Zbořil, M.; Weinheimer, C.; Ostrick, B.; Telle, H. H.

    2013-12-15

    In this paper we describe a new variant of null ellipsometry to determine thicknesses and optical properties of thin films on a substrate at cryogenic temperatures. In the PCSA arrangement of ellipsometry the polarizer and the compensator are placed before the substrate and the analyzer after it. Usually, in the null ellipsometry the polarizer and the analyzer are rotated to find the searched minimum in intensity. In our variant we rotate the polarizer and the compensator instead, both being placed in the incoming beam before the substrate. Therefore the polarisation analysis of the reflected beam can be realized by an analyzer at fixed orientation. We developed this method for investigations of thin cryogenic films inside a vacuum chamber where the analyzer and detector had to be placed inside the cold shield at a temperature of T≈ 90 K close to the substrate. All other optical components were installed at the incoming beam line outside the vacuum chamber, including all components which need to be rotated during the measurements. Our null ellipsometry variant has been tested with condensed krypton films on a highly oriented pyrolytic graphite substrate (HOPG) at a temperature of T≈ 25 K. We show that it is possible to determine the indices of refraction of condensed krypton and of the HOPG substrate as well as thickness of krypton films with reasonable accuracy.

  13. Neutral gas desorption and photoelectric emission from aluminum alloy vacuum chambers exposed to synchrotron radiation

    SciTech Connect

    Groebner, O.; Mathewson, A.G.; Strubin, P.; Alge, E.; Souchet, R.

    1989-03-01

    In an aluminum alloy vacuum chamber exposed to synchrotron radiation, the photoelectron currents produced were measured with the photons incident at low angles on the side wall and compared with normal incidence. The calculated photocurrents for normal incidence, using published values of the photoyield for oxidized Al, agree to within 15% with the measured values. Differences in the photocurrent dependence on photon spectrum at normal and glancing incidence were attributed to low-energy photons being totally reflected and hence producing no photoelectrons. It was established that, at glancing angles of incidence down to 11 mrad, a substantial: more than 20%: fraction of the synchrotron radiation is scattered around the vacuum chamber from the initial point of impact. During exposure to synchrotron radiation, the gases desorbed were H/sub 2/, CO, CO/sub 2/, and CH/sub 4/. The similar shapes of the dependence of the gas desorption and the photoelectron currents on the photon spectrum suggested that it is mainly the photoelectrons that are contributing to the desorption. It was estimated that electrons of 60 eV would produce the same gas desorption as synchrotron radiation with a critical energy of 3 keV.

  14. Ellipsometry with polarisation analysis at cryogenic temperatures inside a vacuum chamber

    NASA Astrophysics Data System (ADS)

    Bauer, S.; Grees, B.; Spitzer, D.; Beck, M.; Bottesch, R.; Ortjohann, H.-W.; Ostrick, B.; Schäfer, T.; Telle, H. H.; Wegmann, A.; Zbořil, M.; Weinheimer, C.

    2013-12-01

    In this paper we describe a new variant of null ellipsometry to determine thicknesses and optical properties of thin films on a substrate at cryogenic temperatures. In the PCSA arrangement of ellipsometry the polarizer and the compensator are placed before the substrate and the analyzer after it. Usually, in the null ellipsometry the polarizer and the analyzer are rotated to find the searched minimum in intensity. In our variant we rotate the polarizer and the compensator instead, both being placed in the incoming beam before the substrate. Therefore the polarisation analysis of the reflected beam can be realized by an analyzer at fixed orientation. We developed this method for investigations of thin cryogenic films inside a vacuum chamber where the analyzer and detector had to be placed inside the cold shield at a temperature of T ≈ 90 K close to the substrate. All other optical components were installed at the incoming beam line outside the vacuum chamber, including all components which need to be rotated during the measurements. Our null ellipsometry variant has been tested with condensed krypton films on a highly oriented pyrolytic graphite substrate (HOPG) at a temperature of T ≈ 25 K. We show that it is possible to determine the indices of refraction of condensed krypton and of the HOPG substrate as well as thickness of krypton films with reasonable accuracy.

  15. Robust Low Cost Aerospike/RLV Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Ellis, David; McKechnie

    1999-01-01

    Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. At the same time, fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of a shrinking NASA budget. In recent years, combustion chambers of equivalent size to the Aerospike chamber have been fabricated at NASA-Marshall Space Flight Center (MSFC) using innovative, relatively low-cost, vacuum-plasma-spray (VPS) techniques. Typically, such combustion chambers are made of the copper alloy NARloy-Z. However, current research and development conducted by NASA-Lewis Research Center (LeRC) has identified a Cu-8Cr-4Nb alloy which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. In fact, researchers at NASA-LeRC have demonstrated that powder metallurgy (P/M) Cu-8Cr-4Nb exhibits better mechanical properties at 1,200 F than NARloy-Z does at 1,000 F. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost, VPS process to deposit Cu-8Cr-4Nb with mechanical properties that match or exceed those of P/M Cu-8Cr-4Nb. In addition, oxidation resistant and thermal barrier coatings can be incorporated as an integral part of the hot wall of the liner during the VPS process. Tensile properties of Cu-8Cr-4Nb material produced by VPS are reviewed and compared to material produced previously by extrusion. VPS formed combustion chamber liners have also been prepared and will be reported on following scheduled hot firing tests at NASA-Lewis.

  16. Alignment Measurements of the Microwave Anisotropy Probe (MAP) Instrument in a Thermal/Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Hill, Michael D.; Herrera, Acey A.; Crane, J. Allen; Packard, Edward A.; Aviado, Carlos; Sampler, Henry P.

    2000-01-01

    The Microwave Anisotropy Probe (MAP) Observatory, scheduled for a fall 2000 launch, is designed to measure temperature fluctuations (anisotropy) and produce a high sensitivity and high spatial resolution (approximately 0.2 degree) map of the cosmic microwave background (CMB) radiation over the entire sky between 22 and 90 GHz. MAP utilizes back-to-back Gregorian telescopes to focus the microwave signals into 10 differential microwave receivers, via 20 feed horns. Proper alignment of the telescope reflectors and the feed horns at the operating temperature of 90 K is a critical element to ensure mission success. We describe the hardware and methods used to validate the displacement/deformation predictions of the reflectors and the microwave feed horns during thermal/vacuum testing of the reflectors and the microwave instrument. The smallest deformation predictions to be measured were on the order of +/- 0.030 inches (+/- 0.762 mm). Performance of these alignment measurements inside a thermal/vacuum chamber with conventional alignment equipment posed several limitations. The most troublesome limitation was the inability to send personnel into the chamber to perform the measurements during the test due to vacuum and the temperature extremes. The photogrammetry (PG) system was chosen to perform the measurements since it is a non- contact measurement system, the measurements can be made relatively quickly and accurately, and the photogrammetric camera can be operated remotely. The hardware and methods developed to perform the MAP alignment measurements using PG proved to be highly successful. The measurements met the desired requirements, for the metal structures enabling the desired distortions to be measured resolving deformations an order of magnitude smaller than the imposed requirements. Viable data were provided to the MAP Project for a full analysis of the on-orbit performance of the Instrument's microwave system.

  17. Vacuum chamber translation/positioning mechanism and welding power supply controller

    NASA Technical Reports Server (NTRS)

    Smith, James E., Jr.; Cashon, John L.

    1992-01-01

    Welding in the vacuum of space represents an important and fundamental problem for space exploration. Repairs or connection of metal components on orbit or during travel to the moon or distant planets may be required. Cracks or holes in spacecraft skin or supporting structures external to the pressurized section will require some type of repair that must be permanently made to the skin or support by welding. The development of a translation/positioning system that will permit research into welding of metal samples in a small vacuum chamber located at Marshall Space Flight Center (MSFC) is addressed. The system and associated software was tested to the extent possible without the availability of the welder power supply or control computer that must be supplied by MSFC. Software has been developed for straight line welding. More extensive and varied translations are possible with simple alterations to the operating software to use the full capabilities of this three axes system. The source code 'VW.BAS' has been provided to serve as an example for further development of the vacuum welder translation system.

  18. CENTAR modelling of the TOPAZ-II: Loss of vacuum chamber cooling during full power ground test

    NASA Astrophysics Data System (ADS)

    Standley, Vaughn H.; Morris, D. Brent; Schuller, Michael J.

    1992-01-01

    The Code for Extended Non-linear Transient Analysis of Extraterrestrial Reactors (CENTAR) was used to model an electrically heated TOPAZ-II thermionic space reactor operating at full power following a loss of coolant to its enclosing vacuum chamber. The purpose of the work was to quantity the response time available to Thermionic System Evaluation Test (TSET) operators following an interruption of vacuum chamber cooling and to test the utility of the CENTAR code for modelling a true-to-life application. A parametric study was done to test key assumptions and to refine the TOPAZ-II input deck being used. The vacuum chamber temperature history was then solved for under the assumption that full power would be maintained (at 115 kWth) during the loss of vacuum chamber cooling. The vacuum chamber temperatures were substituted into the CENTAR input deck for the space temperature variable. Each space temperature was associated with a point in time to simulate transient conditions in the electric heaters, thermionic elements, liquid metal coolant, and radiator. It was verified that the TOPAZ-II equilibrated fast enough such that CENTAR could run in steady state mode to generate a quasi-transient solution. Results indicated that TSET operators would have several minutes to regain total or partial cooling and that drastic action (emergency shutdown of the TOPAZ-II electric heater power, for example) would not be required.

  19. Portable mass spectrometer with one or more mechanically adjustable electrostatic sectors and a mechanically adjustable magnetic sector all mounted in a vacuum chamber

    DOEpatents

    Andresen, B.D.; Eckels, J.D.; Kimmons, J.F.; Martin, W.H.; Myers, D.W.; Keville, R.F.

    1992-10-06

    A portable mass spectrometer is described having one or more electrostatic focusing sectors and a magnetic focusing sector, all of which are positioned inside a vacuum chamber, and all of which may be adjusted via adjustment means accessible from outside the vacuum chamber. Mounting of the magnetic sector entirely within the vacuum chamber permits smaller magnets to be used, thus permitting reductions in both weight and bulk. 13 figs.

  20. Portable mass spectrometer with one or more mechanically adjustable electrostatic sectors and a mechanically adjustable magnetic sector all mounted in a vacuum chamber

    DOEpatents

    Andresen, Brian D.; Eckels, Joel D.; Kimmons, James F.; Martin, Walter H.; Myers, David W.; Keville, Robert F.

    1992-01-01

    A portable mass spectrometer is described having one or more electrostatic focusing sectors and a magnetic focusing sector, all of which are positioned inside a vacuum chamber, and all of which may be adjusted via adjustment means accessible from outside the vacuum chamber. Mounting of the magnetic sector entirely within the vacuum chamber permits smaller magnets to be used, thus permitting reductions in both weight and bulk.

  1. Development of a multipurpose vacuum chamber for serial optical and diffraction experiments with free electron laser radiation

    SciTech Connect

    Rajkovic, I.; Hallmann, J.; Gruebel, S.; More, R.; Quevedo, W.; Petri, M.; Techert, S.

    2010-04-15

    In this paper we present a development of a multipurpose vacuum chamber which primal function is to be used in pump/probe experiments with free electron laser (FEL) radiation. The chamber is constructed for serial diffraction and serial spectroscopy allowing a fast exchange of samples during the measurement process. For the fast exchange of samples, liquid jet systems are used. Both applications, utilizing soft x-ray FEL pulses as pump and optical laser pulses as probe and vice versa are documented. Experiments with solid samples as well as the liquid jet samples are presented. When working with liquid jets, a system of automatically refilled liquid traps for capturing liquids has been developed in order to ensure stable vacuum conditions. Differential pumping stages are placed in between the FEL beamline and the experimental chamber so that working pressure in the chamber can be up to four orders of magnitude higher than the pressure in the FEL beamline.

  2. Development of a multipurpose vacuum chamber for serial optical and diffraction experiments with free electron laser radiation.

    PubMed

    Rajkovic, I; Hallmann, J; Grübel, S; More, R; Quevedo, W; Petri, M; Techert, S

    2010-04-01

    In this paper we present a development of a multipurpose vacuum chamber which primal function is to be used in pump/probe experiments with free electron laser (FEL) radiation. The chamber is constructed for serial diffraction and serial spectroscopy allowing a fast exchange of samples during the measurement process. For the fast exchange of samples, liquid jet systems are used. Both applications, utilizing soft x-ray FEL pulses as pump and optical laser pulses as probe and vice versa are documented. Experiments with solid samples as well as the liquid jet samples are presented. When working with liquid jets, a system of automatically refilled liquid traps for capturing liquids has been developed in order to ensure stable vacuum conditions. Differential pumping stages are placed in between the FEL beamline and the experimental chamber so that working pressure in the chamber can be up to four orders of magnitude higher than the pressure in the FEL beamline. PMID:20441366

  3. Development of a Methodology for Conducting Hall Thruster EMI Tests in Metal Vacuum Chambers of Arbitrary Shape and Size

    NASA Technical Reports Server (NTRS)

    Gallimore, Alec D.

    2000-01-01

    While the closed-drift Hall thruster (CDT) offers significant improvement in performance over conventional chemical rockets and other advanced propulsion systems such as the arcjet, its potential impact on spacecraft communication signals must be carefully assessed before widespread use of this device can take place. To this end, many of the potentially unique issues that are associated with these thrusters center on its plume plasma characteristics and the its interaction with electromagnetic waves. Although a great deal of experiments have been made in characterizing the electromagnetic interference (EMI) potential of these thrusters, the interpretation of the resulting data is difficult because most of these measurements have been made in vacuum chambers with metal walls which reflect radio waves emanating from the thruster. This project developed a means of assessing the impact of metal vacuum chambers of arbitrary size or shape on EMI experiments, thereby allowing for test results to be interpreted properly. Chamber calibration techniques were developed and initially tested at RIAME using their vacuum chamber. Calibration experiments were to have been made at Tank 5 of NASA GRC and the 6 m by 9 m vacuum chamber at the University of Michigan to test the new procedure, however the subcontract to RIAME was cancelled by NASA memorandum on Feb. 26. 1999.

  4. Heavy-ion inertial fusion: influence of target gain on accelerator parameters for vacuum-propagation regimes in reaction chambers

    SciTech Connect

    Mark, J.W.K.; Bangerter, R.O.; Barletta, W.A.; Fawley, W.M.; Judd, D.L.

    1982-03-04

    Target physics imposes requirements on the design of inertial fusion drivers. The influence of beam propagation in near vacuum fusion reaction chambers is evaluated for the relation between target gain and the phase-space requirements of heavy-ion accelerators. Initial results suggest that neutralization of the ion beam has a much greater positive effect than the deleterious one of beam stripping provided that the fusion chamber pressure is < 10/sup -3/ torr (of Li vapor or equivalent).

  5. Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Elam, Sandra; McKechnie, Timothy; Hickman, Robert; Stinson, Thomas N. (Technical Monitor)

    2002-01-01

    Next-generation, regeneratively cooled rocket engines require materials that can meet high temperatures while resisting the corrosive oxidation-reduction reaction of combustion known as blanching, the main cause of engine failure. A project was initiated at NASA-Marshal Space Flight Center (MSFC) to combine three existing technologies to build and demonstrate an advanced liquid rocket engine combustion chamber that would provide a 100 mission life. Technology developed in microgravity research to build cartridges for space furnaces was utilized to vacuum plasma spray (VPS) a functional gradient coating on the hot wall of the combustion liner as one continuous operation, eliminating any bondline between the coating and the liner. The coating was NiCrAlY, developed previously as durable protective coatings on space shuttle high pressure fuel turbopump (HPFTP) turbine blades. A thermal model showed that 0.03 in. NiCrAlY applied to the hot wall of the combustion liner would reduce the hot wall temperature 200 F, a 20% reduction, for longer life. Cu-8Cr-4Nb alloy, which was developed by NASA-Glenn Research Center (GRC), and which possesses excellent high temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability, was utilized as the liner material in place of NARloy-Z. The Cu-8Cr-4Nb material exhibits better mechanical properties at 650 C (1200 F) than NARloy-Z does at 538 C (1000 F). VPS formed Cu-8Cr-4Nb combustion chamber liners with a protective NiCrAlY functional gradient coating have been hot fire tested, successfully demonstrating a durable coating for the first time. Hot fire tests along with tensile and low cycle fatigue properties of the VPS formed combustion chamber liners and witness panel specimens are discussed.

  6. Robust Low Cost Liquid Rocket Combustion Chamber by Advanced Vacuum Plasma Process

    NASA Technical Reports Server (NTRS)

    Holmes, Richard; Elam, Sandra; Ellis, David L.; McKechnie, Timothy; Hickman, Robert; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Next-generation, regeneratively cooled rocket engines will require materials that can withstand high temperatures while retaining high thermal conductivity. Fabrication techniques must be cost efficient so that engine components can be manufactured within the constraints of shrinking budgets. Three technologies have been combined to produce an advanced liquid rocket engine combustion chamber at NASA-Marshall Space Flight Center (MSFC) using relatively low-cost, vacuum-plasma-spray (VPS) techniques. Copper alloy NARloy-Z was replaced with a new high performance Cu-8Cr-4Nb alloy developed by NASA-Glenn Research Center (GRC), which possesses excellent high-temperature strength, creep resistance, and low cycle fatigue behavior combined with exceptional thermal stability. Functional gradient technology, developed building composite cartridges for space furnaces was incorporated to add oxidation resistant and thermal barrier coatings as an integral part of the hot wall of the liner during the VPS process. NiCrAlY, utilized to produce durable protective coating for the space shuttle high pressure fuel turbopump (BPFTP) turbine blades, was used as the functional gradient material coating (FGM). The FGM not only serves as a protection from oxidation or blanching, the main cause of engine failure, but also serves as a thermal barrier because of its lower thermal conductivity, reducing the temperature of the combustion liner 200 F, from 1000 F to 800 F producing longer life. The objective of this program was to develop and demonstrate the technology to fabricate high-performance, robust, inexpensive combustion chambers for advanced propulsion systems (such as Lockheed-Martin's VentureStar and NASA's Reusable Launch Vehicle, RLV) using the low-cost VPS process. VPS formed combustion chamber test articles have been formed with the FGM hot wall built in and hot fire tested, demonstrating for the first time a coating that will remain intact through the hot firing test, and with

  7. Force on a storage ring vacuum chamber after sudden turn-off of a magnet power supply

    NASA Astrophysics Data System (ADS)

    Sinha, Gautam; Prabhu, S. S.

    2011-10-01

    We are commissioning a 2.5 GeV synchrotron radiation source (SRS) where electrons travel in high vacuum inside the vacuum chambers made of aluminum alloys. These chambers are kept between the pole gaps of magnets and are made to facilitate the radiation coming out of the storage ring to the experimental station. These chambers are connected by metallic bellows. During the commissioning phase of the SRS, the metallic bellows became ruptured due to the frequent tripping of the dipole magnet power supply. The machine was down for quite some time. In the case of a power supply trip, the current in the magnets decays exponentially. It was observed experimentally that the fast B field decay generates a large eddy current in the chambers and consequently the chambers are subjected to a huge Lorentz force. This motivated us to develop a theoretical model to study the force acting on a metallic plate when exposed to an exponentially decaying field and then to extend it for a rectangular vacuum chamber. The problem is formulated using Maxwell’s equations and converted to the inhomogeneous Helmholtz equation. After taking the Laplace transform, the equation is solved with appropriate boundary conditions. Final results are obtained after taking the appropriate inverse Laplace transform. The expressions for eddy current contour and magnetic field produced by the eddy current are also derived. Variations of the force on chambers of different wall thickness due to spatially varying and exponentially time decaying field are presented. The result is a general theory which can be applied to different geometries and calculation of power loss as well. Comparisons are made with results obtained by simulation using a finite element based code, for quick verification of the theoretical model.

  8. Assembly of a Vacuum Chamber: A Hands-On Approach to Introduce Mass Spectrometry

    ERIC Educational Resources Information Center

    Bussie`re, Guillaume; Stoodley, Robin; Yajima, Kano; Bagai, Abhimanyu; Popowich, Aleksandra K.; Matthews, Nicholas E.

    2014-01-01

    Although vacuum technology is essential to many aspects of modern physical and analytical chemistry, vacuum experiments are rarely the focus of undergraduate laboratories. We describe an experiment that introduces students to vacuum science and mass spectrometry. The students first assemble a vacuum system, including a mass spectrometer. While…

  9. Construction of a Thermal Vacuum Chamber for Environment Test of Triple CubeSat Mission TRIO-CINEMA

    NASA Astrophysics Data System (ADS)

    Jeon, Jeheon; Lee, Seongwhan; Yoon, Seyoung; Seon, Jongho; Jin, Ho; Lee, Donghun; Lin, Robert P.

    2013-12-01

    TRiplet Ionospheric Observatory-CubeSat for Ion, Neutron, Electron & MAgnetic fields (TRIO-CINEMA) is a CubeSat with 3.14 kg in weight and 3-U (10 × 10 × 30 cm) in size, jointly developed by Kyung Hee University and UC Berkeley to measure magnetic fields of near Earth space and detect plasma particles. When a satellite is launched into orbit, it encounters ultrahigh vacuum and extreme temperature. To verify the operation and survivability of the satellite in such an extreme space environment, experimental tests are conducted on the ground using thermal vacuum chamber. This paper describes the temperature control device and monitoring system suitable for CubeSat test environment using the thermal vacuum chamber of the School of Space Research, Kyung Hee University. To build the chamber, we use a general purpose thermal analysis program and NX 6.0 TMG program. We carry out thermal vacuum tests on the two flight models developed by Kyung Hee University based on the thermal model of the TRIO-CINEMA satellite. It is expected from this experiment that proper operation of the satellite in the space environment will be achieved.

  10. Radial force on the vacuum chamber wall during thermal quench in tokamaks

    NASA Astrophysics Data System (ADS)

    Pustovitov, V. D.

    2015-12-01

    The radial force balance during a thermal quench in tokamaks is analyzed. As a rule, the duration τtp of such events is much shorter than the resistive time τw of the vacuum chamber wall. Therefore, the perturbations of the magnetic field B produced by the evolving plasma cannot penetrate the wall, which makes different the magnetic pressures on its inner and outer sides. The goal of this work is the analytical estimation of the resulting integral radial force on the wall. The plasma is considered axially symmetric; for the description of radial forces on the wall, the results of V.D. Shafranov's classical work [J. Nucl. Energy C 5, 251 (1963)] are used. Developed for tokamaks, the standard equilibrium theory considers three interacting systems: plasma, poloidal field coils, and toroidal field coils. Here, the wall is additionally incorporated with currents driven by ∂ B/∂ t≠0 accompanying the fast loss of the plasma thermal energy. It is shown that they essentially affect the force redistribution, thereby leading to large loads on the wall. The estimates prove that these loads have to be accounted for in the disruptive scenarios in large tokamaks.

  11. Neutral density map of Hall thruster plume expansion in a vacuum chamber

    SciTech Connect

    Walker, Mitchell L.R.; Gallimore, Alec D.

    2005-05-15

    A neutral background pressure map of the large vacuum test facility (LVTF) is presented. The LVTF is mapped at cold anode flow rates of 5.25, 10.46, and 14.09 mg/s. In addition, neutral background pressure maps are created at hot anode (i.e., discharge on) flow rates of 5.25 and 10.46 mg/s for discharge voltages of 300 and 500 V, corresponding to P5 Hall thruster operating conditions ranging from 1.5 to 5.0 kW. The chamber pressure is mapped at nominal xenon pumping speeds of 140,000 and 240,000 l/s. The pressure map is performed with a rake consisting of five calibrated Bayard-Alpert hot-cathode ionization gauges. The plume expansion appears to be independent of anode flow rate and facility background pressure. Analysis of axial pressure profiles on the LVTF's centerline shows that the plume pressure decreases from a maximum at the thruster exit plane down to the facility background pressure at approximately 2 m downstream of the exit plane. Comparison of axial pressure profiles on the LVTF's centerline shows that the neutral density is nearly the same for cold flow and hot flow. The study shows that a cold flow neutral density background map accurately characterizes the neutral density in an operating Hall thruster plume.

  12. Radial force on the vacuum chamber wall during thermal quench in tokamaks

    SciTech Connect

    Pustovitov, V. D.

    2015-12-15

    The radial force balance during a thermal quench in tokamaks is analyzed. As a rule, the duration τ{sub tp} of such events is much shorter than the resistive time τ{sub w} of the vacuum chamber wall. Therefore, the perturbations of the magnetic field B produced by the evolving plasma cannot penetrate the wall, which makes different the magnetic pressures on its inner and outer sides. The goal of this work is the analytical estimation of the resulting integral radial force on the wall. The plasma is considered axially symmetric; for the description of radial forces on the wall, the results of V.D. Shafranov’s classical work [J. Nucl. Energy C 5, 251 (1963)] are used. Developed for tokamaks, the standard equilibrium theory considers three interacting systems: plasma, poloidal field coils, and toroidal field coils. Here, the wall is additionally incorporated with currents driven by ∂B/∂t≠0 accompanying the fast loss of the plasma thermal energy. It is shown that they essentially affect the force redistribution, thereby leading to large loads on the wall. The estimates prove that these loads have to be accounted for in the disruptive scenarios in large tokamaks.

  13. Vacuum chamber eddy current self-correction for the AGS Booster Accelerator

    SciTech Connect

    Danby, G.T.; Jackson, J.W.

    1989-01-01

    The large sextupole and other multipoles induced by eddy currents in the vacuum chamber (VC) designed for the AGS Booster dipoles have been cancelled by simple coils attached to the VC surface. A two turns per pole back leg winding provides the mmf required to power the correction coil by transformer action, automatically correcting even for the variable {dot B} magnet excitation. Much larger VC positional errors of translation and rotation are acceptable because the coils follow the VC contour: the aberrations and their corrections locally have the same misplaced coordinate system. The self-correction concept could be applied to quadrupoles. However, Booster quadrupole measurements show that induced higher harmonics from VC and other eddy current sources are very small. Thus, with self-correction of the dipole VC eddy current fields, {dot B} effects on the proton rapid cycling Booster optics are reduced to tracking of the fundamental dipole and quadrupole fields. This can be automatically controlled using field monitoring transducers located in a dipole and quadrupole operated in series with the Booster magnets. 2 refs., 4 figs.

  14. Magnetically Suspended Linear Pulse Motor for Semiconductor Wafer Transfer in Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Moriyama, Shin-Ichi; Hiraki, Naoji; Watanabe, Katsuhide; Kanemitsu, Yoichi

    1996-01-01

    This paper describes a magnetically suspended linear pulse motor for a semiconductor wafer transfer robot in a vacuum chamber. The motor can drive a wafer transfer arm horizontally without mechanical contact. In the construction of the magnetic suspension system, four pairs of linear magnetic bearings for the lift control are used for the guidance control as well. This approach allows us to make the whole motor compact in size and light in weight. The tested motor consists of a double-sided stator and a transfer arm with a width of 50 mm and a total length of 700 mm. The arm, like a ladder in shape, is designed as the floating element with a tooth width of 4 mm (a tooth pitch of 8 mm). The mover mass is limited to about 1.6 kg by adopting such an arm structure, and the ratio of thrust to mover mass reaches to 3.2 N/kg under a broad air gap (1 mm) between the stator teeth and the mover teeth. The performance testing was carried out with a transfer distance less than 450 mm and a transfer speed less than 560 mm/s. The attitude of the arm was well controlled by the linear magnetic bearings with a combined use, and consequently the repeatability on the positioning of the arm reached to about 2 micron. In addition, the positioning accuracy was improved up to about 30 micron through a compensation of the 128-step wave current which was used for the micro-step drive with a step increment of 62.5 micron.

  15. EDDY CURRENT EFFECT OF THE BNL-AGS VACUUM CHAMBER ON THE OPTICS OF THE BNL-AGS SYNCHROTRON.

    SciTech Connect

    TSOUPAS,N.; AHRENS,L.; BROWN,K.A.; GLENN,J.W.; GARDNER,K.

    1999-03-29

    During the acceleration cycle of the AGS synchrotron, eddy currents are generated within the walls of the vacuum chambers of the AGS main magnets. The vacuum chambers have elliptical cross section, are made of inconel material with a wall thickness of 2 mm and are placed within the gap of the combined-function main magnets of the AGS synchrotron. The generation of the eddy currents in the walls of the vacuum chambers, creates various magnetic multipoles, which affect the optics of the AGS machine. In this report these magnetic multipoles are calculated for various time interval starting at the acceleration cycle, where the magnetic field of the main magnet is {approx}0.1 T, and ending before the beam extraction process, where the magnetic field of the main magnet is almost constant at {approx}1.1 T. The calculations show that the magnetic multipoles generated by the eddy-currents affect the optics of the AGS synchrotron during the acceleration cycle and in particular at low magnetic fields of the main magnet. Their effect is too weak to affect the optics of the AGS machine during beam extraction at the nominal energies.

  16. Compensation for the effect of vacuum chamber eddy current by digital signal processing for closed orbit feedback

    SciTech Connect

    Chung, Y.; Emery, L.; Kirchman, J.

    1993-07-01

    The Advanced Photon Source (APS) will implement both global and local beam position feedback systems to stabilize the particle and X-ray beams. The relatively thick (1/2 inch) aluminum storage ring vacuum chamber at corrector magnet locations for the local feedback systems will induce significant eddy current. This will reduce the correction bandwidth and could potentially destabilize the feedback systems. This paper describes measurement of the effect of the eddy current induced in the APS storage ring vacuum chamber by a horizontal/vertical corrector magnet and its compensation using digital signal processing at 4 kHz sampling frequency with proportional, integral, and derivative (PID) control algorithm for closed orbit feedback. A theory of digital feedback to obtain the linear system responses and the conditions for optimal control will also be presented. The magnet field in the vacuum chamber shows strong quadrupole and sextupole components varying with frequency, in addition to significant attenuation and phase shift with bandwidth ({minus}3 dB) of 20 Hz for horizontal and 4 Hz for vertical fields relative to the magnet current. Large changes in the magnet resistance and inductance were also observed, as the result of reduced total magnetic energy and increased Ohmic heat loss.

  17. A portable micro-X-ray fluorescence spectrometer with polycapillary optics and vacuum chamber for archaeometric and other applications

    NASA Astrophysics Data System (ADS)

    Buzanich, G.; Wobrauschek, P.; Streli, C.; Markowicz, A.; Wegrzynek, D.; Chinea-Cano, E.; Bamford, S.

    2007-11-01

    A portable focused-beam XRF spectrometer was designed, constructed, and manufactured. The spectrometer allows to detect and perform analysis of chemical elements from Na upwards. The system is equipped with a compact vacuum chamber to reduce absorption of both the excitation and the fluorescence radiation in air. A low power Pd-anode tube operated up to 50 kV and 1 mA with a point focus of 400 μm is used as excitation source. A polycapillary lens with a spot size of about 160 μm, or a collimator with a 1 mm inner diameter can be used alternatively for either focusing or collimating the primary beam. The fluorescence radiation is collected by an Si drift detector with an active area of 10 mm 2 and equipped with an 8 μm Be entrance window. A compact vacuum chamber was designed to house the X-ray beam optics and the detector snout. The chamber is attached to the X-ray tube and can be pumped down to 0.1 mbar. A Kapton™ window of 7.5 μm thickness allows to locate the investigated spot at about 1-2 mm distance outside of the chamber, thus minimizing absorption losses in the excitation and X-ray fluorescence radiation paths. Two lasers pointers are mounted inside the chamber. The laser beams cross at a point outside the chamber in front of the entrance window and coincide with the focal spot of the polycapillary. This paper reports some preliminary results obtained from an in situ analysis of bronze samples as well as a comparison of these data with those given by other laboratory spectrometers and the reference values provided by the Italian bronze foundry Venturi Arte Bologna, Italy.

  18. Development and tests of interferometry facility in 6-m diameter radiometer thermal vacuum chamber in Tsukuba Space Center

    NASA Astrophysics Data System (ADS)

    Suganuma, Masahiro; Katayama, Haruyoshi; Naitoh, Masataka; Imai, Tadashi; Miyamoto, Masashi; Maruyama, Kenta; Kaneda, Hidehiro; Tange, Yoshio; Nakagawa, Takao

    2010-07-01

    We present a test of optical metrology for 800-mm spaceborne optics in the 6-m radiometer thermal vacuum chamber at JAXA's Tsukuba Space Center of JAXA. Under the framework of the JAXA's large-optics study program for astronomy and Earth observations, we developed a test bench for interferometric metrology of large optics with an auto-collimation method in the chamber. The optical system was aligned in a horizontal light-axis configuration within the facility limit to handle a 3.5-m aperture telescope like SPICA. A high-speed interferometer was contained in an aluminum and titanmade pressure vessel, which was mounted on the five-axis stage. We tested the 800-mm lightweight C/SiC optics using a 900-mm diameter flat mirror. Alignment changes in tilts of about ten arcseconds were observed as pressure went down from 1 atm to vacuum. After we re-aligned the interferometer and flat mirror, the wavefronts through the optics under vacuum were observed to increase in astigmatism aberration by 0.07λRMS at λ=633nm from under atmosphere, which might be caused by a deformation in the test optics or flat mirror.

  19. The U.S. Lab is lifted out of the vacuum chamber in the O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The U.S. Lab, after successfully completing a leak test inside a vacuum chamber in the Operations and Checkout Building, is lifted up and away from the chamber. A rotation and handling fixture holds the Lab. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  20. The U.S. Lab is lifted out of the vacuum chamber in the O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    After successfully completing a leak test inside a vacuum chamber in the Operations and Checkout Building, the U.S. Lab, a component of the International Space Station, is ready to be lifted and removed from the chamber. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  1. The U.S. Lab is lifted out of the vacuum chamber in the O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    After successfully completing a leak test inside a vacuum chamber in the Operations and Checkout Building, the U.S. Lab, a component of the International Space Station, is ready to be removed from the chamber. Workers check a crane being attached to the rotation and handling fixture that holds the Lab. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  2. The U.S. Lab is lifted out of the vacuum chamber in the O&C Building

    NASA Technical Reports Server (NTRS)

    2000-01-01

    After successfully completing a leak test inside a vacuum chamber in the Operations and Checkout Building, the U.S. Lab, a component of the International Space Station, is lifted out of the chamber. A rotation and handling fixture holds the Lab. The 32,000-pound scientific research lab, named Destiny, is the first Space Station element to spend seven days in the renovated vacuum chamber. Destiny is scheduled to be launched on Shuttle mission STS-98, the 5A assembly mission, targeted for Jan. 18, 2001. During the mission, the crew will install the Lab in the Space Station during a series of three space walks. The STS-98 mission will provide the Station with science research facilities and expand its power, life support and control capabilities. The U.S. Lab module continues a long tradition of microgravity materials research, first conducted by Skylab and later Shuttle and Spacelab missions. Destiny is expected to be a major feature in future research, providing facilities for biotechnology, fluid physics, combustion, and life sciences research.

  3. Cold vacuum chamber for diagnostics: Analysis of the measurements at the Diamond Light Source and impedance bench measurements

    NASA Astrophysics Data System (ADS)

    Voutta, R.; Gerstl, S.; Casalbuoni, S.; Grau, A. W.; Holubek, T.; Saez de Jauregui, D.; Bartolini, R.; Cox, M. P.; Longhi, E. C.; Rehm, G.; Schouten, J. C.; Walker, R. P.; Migliorati, M.; Spataro, B.

    2016-05-01

    The beam heat load is an important input parameter needed for the cryogenic design of superconducting insertion devices. Theoretical models taking into account the different heating mechanisms of an electron beam to a cold bore predict smaller values than the ones measured with several superconducting insertion devices installed in different electron storage rings. In order to measure and possibly understand the beam heat load to a cold bore, a cold vacuum chamber for diagnostics (COLDDIAG) has been built. COLDDIAG is equipped with temperature sensors, pressure gauges, mass spectrometers as well as retarding field analyzers which allow to measure the beam heat load, total pressure, and gas content as well as the flux of particles hitting the chamber walls. COLDDIAG was installed in a straight section of the Diamond Light Source (DLS). In a previous paper the experimental equipment as well as the installation of COLDDIAG in the DLS are described [S. Gerstl et al., Phys. Rev. ST Accel. Beams 17, 103201 (2014)]. In this paper we present an overview of all the measurements performed with COLDDIAG at the DLS and their detailed analysis, as well as impedance bench measurements of the cold beam vacuum chamber performed at the Karlsruhe Institute of Technology after removal from the DLS. Relevant conclusions for the cryogenic design of superconducting insertion devices are drawn from the obtained results.

  4. TiN coating of the PEP-II low-energy ring aluminum arc vacuum chambers

    SciTech Connect

    Kennedy, K.; Harteneck, B.; Millos, G.

    1997-05-01

    The PEP-II Low-Energy Ring will operate at a nominal energy of 3.1 GeV with a positron beam current of 2.1 A. Design parameters for vacuum components are 3.5 GeV at 3 A. The arc vacuum system is based on an aluminum antechamber concept. It consists of 192 pairs of 2 m long magnet chambers and 5.5 m long pumping chambers. Titanium nitride coating of the entire positron duct is needed in order to suppress beam instabilities caused by multipactoring and the {open_quotes}electron-cloud{close_quotes} effect. An extensive R&D program has been conducted to develop coating parameters that give proper stoichiometry and a suitable thickness of TiN. The total secondary emission yield of TiN-coated aluminum coupons has been measured after the samples were exposed to air and again after electron-beam bombardment. A coating facility has been built to cope with the large quantity of production chambers and the very tight schedule requirements.

  5. SPEAKING IN LIGHT - Jupiter radio signals as deflections of light-emitting electron beams in a vacuum chamber

    NASA Astrophysics Data System (ADS)

    Petrovic, K.

    2015-10-01

    Light emitting electron beam generated in a vacuum chamber is used as a medium for visualizing Jupiter's electromagnetic radiation. Dual dipole array antenna is receiving HF radio signals that are next amplified to radiate a strong electromagnetic field capable of influencing the propagation of electron beam in plasma. Installation aims to provide a platform for observing the characteristics of light emitting beam in 3D, as opposed to the experiments with cathode ray tubes in 2-dimensional television screens. Gas giant 'speaking' to us by radio waves bends the light in the tube, allowing us to see and hear the messages of Jupiter - God of light and sky.

  6. Technical Capability Upgrades to the NASA Langley Research Center 6 ft. by 6 ft. Thermal Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    Thornblom, Mark N.; Beverly, Joshua; O'Connell, Joseph J.; Mau, Johnny C.; Duncan, Dwight L.

    2014-01-01

    The 6 ft. by 6 ft. thermal vacuum chamber (TVAC), housed in Building 1250 at the NASA Langley Research Center (LaRC), and managed by the Systems Integration and Test Branch within the Engineering Directorate, has undergone several significant modifications to increase testing capability, safety, and quality of measurements of articles under environmental test. Significant modifications include: a new nitrogen thermal conditioning unit for controlling shroud temperatures from -150degC to +150degC; two horizontal auxiliary cold plates for independent temperature control from -150degC to +200degC; a suite of contamination monitoring sensors for outgassing measurements and species identification; signal and power feed-throughs; new pressure gauges; and a new data acquisition and control commanding system including safety interlocks. This presentation will provide a general overview of the LaRC 6 ft. by 6 ft. TVAC chamber, an overview of the new technical capabilities, and illustrate each upgrade in detail, in terms of mechanical design and predicted performance. Additionally, an overview of the scope of tests currently being performed in the chamber will be documented, and sensor plots from tests will be provided to show chamber temperature and pressure performance with actual flight hardware under test.

  7. METALLIZATION OF CERAMIC VACUUM CHAMBERS FOR SNS RING INJECTION KICKER MAGNETS.

    SciTech Connect

    HE,P.; HSEUH,H.C.; TODD,R.J.

    2002-04-22

    Ceramic chambers will be used in the pulsed kicker magnets for the injection of H{sup -} into the US Spallation Neutron Source (SNS) accumulator ring. There are two reasons for using ceramic chambers in kickers: (1) to avoid shielding of a fast-changing external magnetic field by metallic chamber walls; and (2) to reduce heating due to eddy currents. The inner surfaces of the ceramic chambers will be coated with a conductive layer, possibly titanium (Ti) or copper with a titanium nitride (TiN) overlayer, to reduce the beam coupling impedance and provide passage for beam image current. This paper describes the development of sputtering method for the 0.83m long 16cm inner diameter ceramic chambers. Coatings of Ti, Cu and TiN with thicknesses up to 10 {micro}m were produced by means of DC magnetron sputtering. The difficulty of coating insulators was overcome with the introduction of an anode screen. Films with good adhesion, uniform longitudinal thickness, and conductivity were produced.

  8. Vacuum Plasma Spray of Cu-8Cr-4Nb for Advanced Liquid-Fuel Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Zimmerman, F.; Elam, S.; Ellis, D.; Miller, H.; McKechnie, T.; Hickman, R.

    2001-01-01

    Vacuum plasma spray (VPS) formed Cu-8Cr-4Nb alloy, with low oxygen, exhibits higher strength at room and elevated temperature than material formed by extrusion. The VPS formed material exhibits slightly lower ductility than the extruded material. VPS forming of Cu-8Cr-4Nb can be used to produce near net structures with mechanical properties comparable to current extruded material.

  9. The V-3 contamination test of the chamber A facility and a subsequent cryogenic/vacuum study of the V-3 test quartz crystal microbalance

    NASA Technical Reports Server (NTRS)

    Moore, W. W., Jr.; Tashbar, P. W.

    1973-01-01

    The areas of orbital and ground contamination of flight experiment hardware have been well established. This report relates directly to results of vacuum chamber testing for the ground evaluation of flight experiment hardware performance. First, the data obtained during the V-3 contamination testing in the Johnson Space Center's Chamber A space simulation test facility are presented. Second, during the V-3 contamination tests, the MSFC Space Sciences Laboratory's quartz crystal microbalance exhibited two periods of anomalous readings. Therefore, a subsequent small chamber tests was conducted in a controlled cryogenic/vacuum environment. The objective was to reproduce with known parameters the anomalous behavior patterns of the V-3 test data. Analyses of the anomalous readings are made on the basis of these tests. Additionally, as a by-product of the small chamber tests, calibration curves then existing for the quartz crystal microbalance were empirically extended, and certain data-formatting aids were documented.

  10. Signal generator exciting an electromagnetic field for ion beam transport to the vacuum chamber of a mass spectrometer

    NASA Astrophysics Data System (ADS)

    Tubol'tsev, Yu. V.; Kogan, V. T.; Bogdanov, A. A.; Chichagov, Yu. V.; Antonov, A. S.

    2015-02-01

    A high-voltage high-frequency signal generator is described that excites an electric field for ion beam transport from an ion source to the vacuum chamber of a mass spectrometer. Excitation signals to the number of two are high-frequency sine-wave out-of-phase signals with the same amplitudes. The amplitude and phase of the signals vary from 20 to 100 V and from 10 kHz to 1 MHz, respectively. The generator also produces a controlled bias voltage in the interval 50-200 V. The frequency and amplitude of the signals, as well as the bias voltage, are computer-controlled via the USB interface.

  11. SECONDARY ELECTRON EMISSION MEASUREMENTS FOR TIN COATING ON THE STAINLESS STEEL OF SNS ACCUMULATOR RING VACUUM CHAMBER.

    SciTech Connect

    HE,P.HSEUH,H.C.TODD,R.J.ET AL.

    2004-07-05

    BNL is responsible for the design and construction of the US Spallation Neutron Source (SNS) accumulator ring. Titanium Nitride (TiN) coating on the stainless steel vacuum chamber of the SNS accumulator ring is needed to reduce the secondary electron yield (SEY) and the undesirable resonant multiplication of electrons. The total SEY of TiN coated stainless steel material has been measured after coating samples were exposed to air and after electron and ion bombardment. We report here about TiN coating system setup at BNL and SEY measurements results at CERN, SLAC and KEK. We also present some simulation results of SNS accumulator ring electron-cloud effects using different SEY values.

  12. Characterization of cryo-vacuum chamber windows for NIRCam instrument alignment and testing

    NASA Astrophysics Data System (ADS)

    Schweiger, Paul F.; Andersen, Torben B.

    2015-09-01

    The Near Infrared Camera (NIRCam) instrument used to align and obtain science data for NASA's James Webb Space Telescope (JWST) was tested at the module level at flight-like cryogenic temperature. This paper explains the innovative techniques used to measure the precise location and orientation of the modules. A laser tracker was used to precision locate the instrument, using a flat reference mirror/reticle surface on the modules inside a chamber through its port windows. This technique established 6 degrees of freedom of position and orientation. The accuracy achieved was on the order of 20 microns in position and 5 arc-seconds in angular orientation.

  13. Measurement of Ultra Low OutGassing Rates for NLC UHV Vacuum Chambers

    SciTech Connect

    Eriksson, Leif S.

    2002-08-12

    Ultra low outgassing rates would be highly advantageous in accelerators and storage rings, such as the Next Linear Collider (NLC), where an outgassing rate of <10{sup -12} Torr liter/sec/cm{sup 2} could eliminate the need for costly distributed pumping. Measuring such low outgassing rates at room temperature has many difficulties. However, by inspection of Fick's law, it can be seen that thermal desorption is proportional to outgassing rate. It is commonly observed that the outgas rate doubles approximately every 15 C for temperatures under 100 C. By measuring outgassing rate versus temperature and time and extrapolating back to room temperature we can measure outgassing rates that would otherwise be difficult to make. To produce a reliable measurement also requires the total surface area under study to be approximately an order of magnitude greater than the area of the measurement chamber walls. To accomplish this, 27 plates of 5083 aluminum were placed in the measurement chamber. This technique will be the basis for future investigation of outgassing rates of other sample plates fabricated with different machining and cleaning techniques.

  14. Measurement of Ultra Low Outgassing Rates for NLC UHV Vacuum Chambers

    SciTech Connect

    Kishiyama, K; Shen, S; Behne, D; Corlett, J N; Atkinson, D; Kennedy, K; Miller, T; Eriksson, L; Ross, M

    2001-06-12

    Ultra low outgassing rates would be highly advantageous in accelerators and storage rings, such as the Next Linear Collider (NLC), where an outgassing rate of <10{sup -12} Torr liter/sec/cm{sup 2} could eliminate the need for costly distributed pumping. Measuring such low outgassing rates at room temperature has many difficulties. However, by inspection of Fick's law, it can be seen that thermal desorption is proportional to outgassing rate. It is commonly observed that the outgas rate doubles approximately every 15 C for temperatures under 100 C. By measuring outgassing rate versus temperature and time and extrapolating back to room temperature we can measure outgassing rates that would otherwise be difficult to make. To produce a reliable measurement also requires the total surface area under study to be approximately an order of magnitude greater than the area of the measurement chamber walls. To accomplish this, 27 plates of 5083 aluminum were placed in the measurement chamber. This technique will be the basis for future investigation of outgassing rates of other sample plates fabricated with different machining and cleaning techniques.

  15. Housing protects laser in vacuum

    NASA Technical Reports Server (NTRS)

    Canali, V. G.

    1978-01-01

    Airtight housing encloses laser for easy alinement and operation in high-vacuum chamber. Beam is transmitted through window into vacuum chamber. Flexible line runs through vacuum chamber to outside, maintaining laser enclosure at atmospheric pressure.

  16. Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber

    NASA Astrophysics Data System (ADS)

    Manova, D.; Bergmann, A.; Mändl, S.; Neumann, H.; Rauschenbach, B.

    2012-11-01

    Here, the integration of a low energy, linearly variable ion beam current density, mechanically in situ adjustable broad beam ion source with a high-temperature x-ray diffraction (XRD) vacuum chamber is reported. This allows in situ XRD investigation of phase formation and evolution processes induced by low energy ion implantation. Special care has been taken to an independent adjustment of the ion beam for geometrical directing towards the substrate, a 15 mm small ion source exit aperture to avoid a secondary sputter process of the chamber walls, linearly variable ion current density by using a pulse length modulation (PLM) for the accelerating voltages without changing the ion beam density profile, nearly homogeneous ion beam distribution over the x-ray footprint, together with easily replaceable Kapton® windows for x-rays entry and exit. By combining a position sensitive x-ray detector with this PLM-modulated ion beam, a fast and efficient time resolved investigation of low energy implantation processes is obtained in a compact experimental setup.

  17. Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber

    SciTech Connect

    Manova, D.; Bergmann, A.; Maendl, S.; Neumann, H.; Rauschenbach, B.

    2012-11-15

    Here, the integration of a low energy, linearly variable ion beam current density, mechanically in situ adjustable broad beam ion source with a high-temperature x-ray diffraction (XRD) vacuum chamber is reported. This allows in situ XRD investigation of phase formation and evolution processes induced by low energy ion implantation. Special care has been taken to an independent adjustment of the ion beam for geometrical directing towards the substrate, a 15 mm small ion source exit aperture to avoid a secondary sputter process of the chamber walls, linearly variable ion current density by using a pulse length modulation (PLM) for the accelerating voltages without changing the ion beam density profile, nearly homogeneous ion beam distribution over the x-ray footprint, together with easily replaceable Kapton{sup Registered-Sign} windows for x-rays entry and exit. By combining a position sensitive x-ray detector with this PLM-modulated ion beam, a fast and efficient time resolved investigation of low energy implantation processes is obtained in a compact experimental setup.

  18. Photon stimulated desorption from a vacuum chamber at the National Synchrotron Light Source

    SciTech Connect

    Kobari, T.; Halama, H.J.

    1987-07-01

    In our search for surfaces exhibiting the lowest photon stimulated desorption, we have exposed a 3-m-long beam tube to photons from the vacuum ultraviolet ring of the National Synchrotron Light Source having critical energy of --500 eV. Desorption of H/sub 2/, CH/sub 4/, CO, and CO/sub 2/, which are the main gas species, was studied as a function of the beam dose for the following surface treatments: standard chemical cleaning, Ar 10% O/sub 2/ glow discharge, N/sub 2/ glow discharge, and radio frequency glow discharge using O/sub 2/ disassociation. In addition, we measured the desorption as a function of vertical collimator position. N/sub 2/ glow discharge treatment yielded the lowest desorption.

  19. Robert Hooke, inventor of the vacuum pump and the first altitude chamber (1671).

    PubMed

    Harsch, Viktor

    2006-08-01

    Robert Hooke (1635-1703), an assistant researcher to Robert Boyle (1627-1691), invented the first functional British air pump. Applying it to scientific research, Hooke operated the world's first hypobaric chamber in 1671, using it for self-experimentation. He recorded the first physiological observations in an artificial altitude-equivalent environment up to 2400 m. Though Hooke's experiment showed some methodological insufficiencies, his imaginative experimental techniques were remarkable for their time and were indicative of the lively intellectual atmosphere of the Royal Society and the significant contributions of Hooke, who was a member. Two centuries passed before the French physiologist Paul Bert (1830-1886) conducted his famous laboratory-supported investigations of high altitude physiology. Bert played a decisive role in the discovery of the causes of decompression sickness; a contribution Hooke could not make due to the technical deficiencies of the 17th century. PMID:16909884

  20. The U.S. Lab is lifted and placed in vacuum chamber in O&C

    NASA Technical Reports Server (NTRS)

    2000-01-01

    CO2 study site manager and plant physiologist Graham Hymus (left) examines scrub oak foliage while project engineer David Johnson (right) looks on. The life sciences study is showing that rising levels of carbon dioxide in our atmosphere, caused by the burning of fossil fuels, could spur plant growth globally. The site of KSC's study is a natural scrub oak area near the Vehicle Assembly Building. Twelve-foot areas of scrub oak have been enclosed in 16 open-top test chambers into which CO2 has been blown. Five scientists from NASA and the Smithsonian Environmental Research Center in Edgewater, Md., work at the site to monitor experiments and keep the site running. Scientists hope to continue the study another five to 10 years. More information on this study can be found in Release No. 57- 00. Additional photos can be found at: www- pao.ksc.nasa.gov/captions/subjects/co2study.htm

  1. Alignment Measurements of the Microwave Anisotropy Probe (MAP) Instrument in a Thermal/Vacuum Chamber Using Photogrammetry

    NASA Technical Reports Server (NTRS)

    Hill, Michael D.; Herrera, Acey A.; Crane, J. Allen; Packard, Edward A.; Aviado, Carlos; Sampler, Henry P.; Obenschain, Arthur (Technical Monitor)

    2000-01-01

    The Microwave Anisotropy Probe (MAP) Observatory, scheduled for a late 2000 launch, is designed to measure temperature fluctuations (anisotropy) and produce a high sensitivity and high spatial resolution (< 0.3 deg at 90 GHz.) map of the cosmic microwave background (CMB) radiation over the entire sky between 22 and 90 GHz. MAP utilizes back-to-back Gregorian telescopes to focus the microwave signals into 10 differential microwave receivers, via 20 feed horns. Proper alignment of the telescope reflectors and the feed horns at the operating temperature of 90 K is a critical element to ensure mission success. We describe the hardware and methods used to validate the displacement/deformation predictions of the reflectors and the microwave feed horns during thermal/vacuum testing of the reflectors and the microwave instrument. The smallest deformations to be resolved by the measurement system were on the order of +/- 0.030 inches (0.762 mm). Performance of these alignment measurements inside a thermal/vacuum chamber with conventional alignment equipment posed several limitations. A photogrammetry (PG) system was chosen to perform the measurements since it is a non-contact measurement system, the measurements can be made relatively quickly and accurately, and the photogrammetric camera can be operated remotely. The hardware and methods developed to perform the MAP alignment measurements using PG proved to be highly successful. The PG measurements met the desired requirements, enabling the desired deformations to be measured and even resolved to an order of magnitude smaller than the imposed requirements. Viable data were provided to the MAP Project for a full analysis of the on-orbit performance of the Instrument's microwave system.

  2. The Use of the Molecular Adsorber Coating Technology to Mitigate Vacuum Chamber Contamination During Pathfinder Testing for the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  3. Distributed I/O Control System Implementation for the 1238 Optical Witness Sample Thermoelectric Quartz Crystal Microbalance Thermal Vacuum Bakeout Chamber

    NASA Technical Reports Server (NTRS)

    Buchanan, Randy K.

    2002-01-01

    The 1238 Thermal Vacuum Bakeout Chamber is used to test materials to determine if they meet space program contamination requirements. The system was previously manual in its operation, in that there was no supervisory control system and therefore, no means for automated operation. Marshall Space Flight Center (MSFC) requested that its operation be automated. The subsequent process implemented involved a hybrid scenario that included existing hardware, a distributed input and output (I/O) system and a graphical user interface (GUI).

  4. A Multi-Chamber System for Analyzing the Outgassing, Deposition,and Associated Optical Degradation Properties of Materials in a Vacuum

    SciTech Connect

    Singal, Jack; Schindler, Rafe; Chang, Chihway; Czodrowski, Patrick; Kim, Peter; /KIPAC, Menlo Park /SLAC /Stanford U.

    2009-12-11

    We report on the Camera Materials Test Chamber, a multi-vessel apparatus which analyzes the outgassing consequences of candidate materials for use in the vacuum cryostat of a new telescope camera. The system measures the outgassing products and rates of samples of materials at different temperatures, and collects films of outgassing products to measure the effects on light transmission in six optical bands. The design of the apparatus minimizes potential measurement errors introduced by background contamination.

  5. Harmonics suppression of vacuum chamber eddy current-induced fields with application to the Superconducting Super Collider Low Energy Booster Magnets

    SciTech Connect

    Schlueter, R.; Halbach, K.

    1992-01-01

    This report presents the formulation of an expression for eddy currents induced in a thin-walled conductor due to a time-dependent electromagnet field excitation. Then follows an analytical development for prediction of vacuum chamber eddy current-induced field harmonics in iron-core electromagnets. A passive technique for harmonics suppression is presented with specific application to the design of the Superconducting Super Collider Low Energy Booster Magnets.

  6. Harmonics suppression of vacuum chamber eddy current induced fields with application to the Superconducting Super Collider (SSC) Low Energy Booster (LEB) Magnets

    SciTech Connect

    Schlueter, R.D.; Halbach, K.

    1991-12-04

    This memo presents the formulation of an expression for eddy currents induced in a thin-walled conductor due to a time-dependent electromagnet field excitation. Then follows an analytical development for prediction of vacuum chamber eddy current induced field harmonics in iron-core electromagnets. A passive technique for harmonics suppression is presented with specific application to the design of the Superconducting Super Collider (SSC) Low Energy B (LEB) Magnets.

  7. How reduced vacuum pumping capability in a coating chamber affects the laser damage resistance of HfO2/SiO2 antireflection and high reflection coatings.

    DOE PAGESBeta

    Field, Ella Suzanne; Bellum, John Curtis; Kletecka, Damon E.

    2016-06-01

    Optical coatings with the highest laser damage thresholds rely on clean conditions in the vacuum chamber during the coating deposition process. A low base pressure in the coating chamber, as well as the ability of the vacuum system to maintain the required pressure during deposition, are important aspects of limiting the amount of defects in an optical coating that could induce laser damage. Our large optics coating chamber at Sandia National Laboratories normally relies on three cryo pumps to maintain low pressures for e-beam coating processes. However, on occasion, one or more of the cryo pumps have been out ofmore » commission. In light of this circumstance, we explored how deposition under compromised vacuum conditions resulting from the use of only one or two cryo pumps affects the laser-induced damage thresholds of optical coatings. Finally, the coatings of this study consist of HfO2 and SiO2 layer materials and include antireflection coatings for 527 nm at normal incidence, and high reflection coatings for 527 nm, 45⁰ angle of incidence (AOI), in P-polarization (P-pol).« less

  8. All-metal superconducting planar microwave resonator

    NASA Astrophysics Data System (ADS)

    Horsley, Matt; Pereverzev, Sergey; Dubois, Jonathon; Friedrich, Stephan; Qu, Dongxia; Libby, Steve; Lordi, Vincenzo; Carosi, Gianpaolo; Stoeffl, Wolfgang; Chapline, George; Drury, Owen; Quantum Noise in Superconducting Devices Team

    There is common agreement that noise and resonance frequency jitter in superconducting microwave planar resonators are caused by presence of two-level systems, or fluctuators, in resonator materials- in dielectric substrate, in superconducting and dielectric layers and on the boundaries and interfaces. Scaling of noise with device dimensions indicate that fluctuators are likely concentrated around boundaries; physical nature of those fluctuators remains unclear. The presence of dielectrics is not necessary for the superconducting device functionality, and one can ask question about properties of all-metal device, where dielectric substrate and oxide films on metal are absent. Resonator made from of thin conducting layer with cuts in it is usually called slot line resonator. We report on the design, fabrication and initial testing of multiple split rings slot line resonator made out of thin molybdenum plate. This work is being funded as part of a three year strategic initiative (LDRD 16-SI-004) to better understand noise in superconducting devices.

  9. Design of an ultrahigh vacuum transfer mechanism to interconnect an oxide molecular beam epitaxy growth chamber and an x-ray photoemission spectroscopy analysis system

    SciTech Connect

    Rutkowski, M. M.; Zeng Zhaoquan; McNicholas, K. M.; Brillson, L. J.

    2013-06-15

    We designed a mechanism and the accompanying sample holders to transfer between a VEECO 930 oxide molecular beam epitaxy (MBE) and a PHI Versa Probe X-ray photoemission spectroscopy (XPS) chamber within a multiple station growth, processing, and analysis system through ultrahigh vacuum (UHV). The mechanism consists of four parts: (1) a platen compatible with the MBE growth stage, (2) a platen compatible with the XPS analysis stage, (3) a sample coupon that is transferred between the two platens, and (4) the accompanying UHV transfer line. The mechanism offers a robust design that enables transfer back and forth between the growth chamber and the analysis chamber, and yet is flexible enough to allow transfer between standard sample holders for thin film growth and masked sample holders for making electrical contacts and Schottky junctions, all without breaking vacuum. We used this mechanism to transfer a barium strontium titanate thin film into the XPS analysis chamber and performed XPS measurements before and after exposing the sample to the air. After air exposure, a thin overlayer of carbon was found to form and a significant shift ({approx}1 eV) in the core level binding energies was observed.

  10. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  11. Capabilities, Design, Construction and Commissioning of New Vibration, Acoustic, and Electromagnetic Capabilities Added to the World's Largest Thermal Vacuum Chamber at NASA's Space Power Facility

    NASA Technical Reports Server (NTRS)

    Motil, Susan M.; Ludwiczak, Damian R.; Carek, Gerald A.; Sorge, Richard N.; Free, James M.; Cikanek, Harry A., III

    2011-01-01

    NASA s human space exploration plans developed under the Exploration System Architecture Studies in 2005 included a Crew Exploration Vehicle launched on an Ares I launch vehicle. The mass of the Crew Exploration Vehicle and trajectory of the Ares I coupled with the need to be able to abort across a large percentage of the trajectory generated unprecedented testing requirements. A future lunar lander added to projected test requirements. In 2006, the basic test plan for Orion was developed. It included several types of environment tests typical of spacecraft development programs. These included thermal-vacuum, electromagnetic interference, mechanical vibration, and acoustic tests. Because of the size of the vehicle and unprecedented acoustics, NASA conducted an extensive assessment of options for testing, and as result, chose to augment the Space Power Facility at NASA Plum Brook Station, of the John H. Glenn Research Center to provide the needed test capabilities. The augmentation included designing and building the World s highest mass capable vibration table, the highest power large acoustic chamber, and adaptation of the existing World s largest thermal vacuum chamber as a reverberant electromagnetic interference test chamber. These augmentations were accomplished from 2007 through early 2011. Acceptance testing began in Spring 2011 and will be completed in the Fall of 2011. This paper provides an overview of the capabilities, design, construction and acceptance of this extraordinary facility.

  12. Technical specification for vacuum systems

    SciTech Connect

    Khaw, J.

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10/sup -5/ to 10/sup -11/ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place a major emphasis on eliminating contamination sources. The specifications and procedures have been written to insure the cleanliness and vacuum integrity of all SLAC vacuum systems, and to assist personnel involved with SLAC vacuum systems in choosing and designing components that are compatible with existing systems and meet the quality and reliability of SLAC vacuum standards. The specification includes requirements on design, procurement, fabrication, chemical cleaning, clean room practices, welding and brazing, helium leak testing, residual gas analyzer testing, bakeout, venting, and pumpdown. Also appended are specifications regarding acceptable vendors, isopropyl alcohol, bakeable valve cleaning procedure, mechanical engineering safety inspection, notes on synchrotron radiation, and specifications of numerous individual components. (LEW)

  13. Thermal analysis simulation for a spin-motor used in the advanced main combustion chamber vacuum plasma spray project using the SINDA computer program

    NASA Technical Reports Server (NTRS)

    Mcdonald, Gary H.

    1990-01-01

    One of the many design challenges of this project is predicting the thermal effects due to the environment inside the vacuum chamber on the turntable and spin motor spindle assembly. The objective of the study is to model the spin motor using the computer program System Improved Numerical Differencing Analyzer (SINDA). By formulating the appropriate input information concerning the motor's geometry, coolant flow path, material composition, and bearing and motor winding characteristics, SINDA should predict temperatures at various predefined nodes. From these temperatures, hopefully, one can predict if the coolant flow rate is sufficient or if certain mechanical elements such as bearings, O ring seals, or motor windings will exceed maximum design temperatures.

  14. Formulation of the arbitrary n stability problem in an axisymmetric torus with a finite resistivity vacuum chamber and PF system

    SciTech Connect

    Berge, G.; Freidberg, J. P.

    1992-06-30

    This work is within the framework of MHD. We study a confined plasma surrounded by a vacuum region and bounded by a resistive wall. Confined to axisymmetric systems, Chapter 1 deals with a fairly general theory for such systems. To be more specific, we are interested here in the case where the configuration is stable in the presence of an infinitely conducting wall, but unstable without the wall. For physical reasons an infinitely conducting wall cannot be made. It is therefore of interest to study the effect of a resistive wall. This is done in Chapter 1. The results in Chapter 1 depend upon knowledge of the solution for the stability problem in the two limiting cases. 1. The wall and the conductors in the vacuum region are not taken into account (wall and conductors at infinity). 2. The wall and the conductors in the vacumm region are taken into account as infinitely conducting elements in the proximity of the plasma. It appears to be the case that even the last of these problem areas has yet to be comprehensively studied, probably because it is rather complex. This is the subject of Chapter 2.

  15. Sunspot: A program to model the behavior of hypervelocity impact damaged multilayer insulation in the Sunspot thermal vacuum chamber of Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rule, W. K.; Hayashida, K. B.

    1992-01-01

    The development of a computer program to predict the degradation of the insulating capabilities of the multilayer insulation (MLI) blanket of Space Station Freedom due to a hypervelocity impact with a space debris particle is described. A finite difference scheme is used for the calculations. The computer program was written in Microsoft BASIC. Also described is a test program that was undertaken to validate the numerical model. Twelve MLI specimens were impacted at hypervelocities with simulated debris particles using a light gas gun at Marshall Space Flight Center. The impact-damaged MLI specimens were then tested for insulating capability in the space environment of the Sunspot thermal vacuum chamber at MSFC. Two undamaged MLI specimens were also tested for comparison with the test results of the damaged specimens. The numerical model was found to adequately predict behavior of the MLI specimens in the Sunspot chamber. A parameter, called diameter ratio, was developed to relate the nominal MLI impact damage to the apparent (for thermal analysis purposes) impact damage based on the hypervelocity impact conditions of a specimen.

  16. Vacuum test bench for high-voltage tests of storage chambers in the electric dipole moment spectrometer

    NASA Astrophysics Data System (ADS)

    Lasakov, M. S.; Polyushkin, A. O.; Serebrov, A. P.; Kolomenskii, E. A.; Pirozhkov, A. N.; Krasnoshchekova, I. A.

    2016-04-01

    We describe the structure of the high-voltage test bench for checking individual insulators and their assemblies with separate control of leakage currents in each insulator. The test bench is mainly intended for preparing the high-voltage block of the spectrometer for the search for the electric dipole moment (EDM) of the neutron. The main part of the bench is the high-voltage source with controllable polarity and voltages up to 200 kV with complex control over parameters. An analogous converter is used in experiment on measuring the EDM of the neutron. We report on the results of testing the new design of the storage chambers of the EDM spectrometer operating with a high voltage; we also test the maximal potentialities of the converter under nearly working conditions; its optimization and calibration are performed.

  17. Vapor-barrier Vacuum Isolation System

    NASA Technical Reports Server (NTRS)

    Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

    2014-01-01

    A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

  18. Measurements of the Propagation of EM Waves through the Vacuum Chamber of the PEP-II Low Energy Ring for Beam Diagnostics

    SciTech Connect

    Byrd, John Michael; De Santis, S.; Pivi, MTF; /SLAC

    2008-01-23

    We present the results of our measurements of the electron cloud density in the PEP-II low energy ring (LER) by propagating a TE wave into the beam pipe. By connecting a signal generator to a beam position monitor button we can excite a signal above the vacuum chamber cut-off frequency and measure its propagation through the beam pipe with a spectrum analyzer connected to another button about 50 meters away. The measurement can be performed with different beam conditions and also at different settings of the solenoids used to reduce the build up of electrons. The presence of a modulation in the TE wave transmission, synchronous with the beam revolution frequency, which appear to increase in depth when the solenoids are switched off, seem to be directly correlated to the electron cloud density in the region between the two BPM's. In this paper we present and discuss the measurements taken in the Interaction Region 12 straight of the LER during 2006 and the first part of 2007.

  19. All-metal metamaterial slow-wave structure for high-power sources with high efficiency

    SciTech Connect

    Wang, Yanshuai; Duan, Zhaoyun Tang, Xianfeng; Wang, Zhanliang; Zhang, Yabin; Gong, Yubin; Feng, Jinjun

    2015-10-12

    In this paper, we have proposed a metamaterial (MTM) which is suitable for the compact high-power vacuum electron devices. For example, an S-band slow-wave structure (SWS) based on the all-metal MTMs has been studied by both simulation and experiment. The results show that this MTM SWS is very helpful to miniaturize the high-power vacuum electron devices and largely improve the output power and the electronic efficiency. The simulation model of an S-band MTM backward wave oscillator (BWO) is built, and the particle-in-cell simulated results are presented here: a 2.454 GHz signal is generated and its peak output power is 4.0 MW with a higher electronic efficiency of 31.5% relative to the conventional BWOs.

  20. NSLS II Vacuum System

    SciTech Connect

    Ferreira, M.; Doom, L.; Hseuh, H.; Longo, C.; Settepani, P.; Wilson, K.; Hu, J.

    2009-09-13

    National Synchrotron Light Source II, being constructed at Brookhaven, is a 3-GeV, 500 mA, 3rd generation synchrotron radiation facility with ultra low emittance electron beams. The storage ring vacuum system has a circumference of 792 m and consists of over 250 vacuum chambers with a simulated average operating pressure of less than 1 x 10{sup -9} mbar. A summary of the update design of the vacuum system including girder supports of the chambers, gauges, vacuum pumps, bellows, beam position monitors and simulation of the average pressure will be shown. A brief description of the techniques and procedures for cleaning and mounting the chambers are given.

  1. Vacuum leak detector

    NASA Technical Reports Server (NTRS)

    Kazokas, G. P. (Inventor)

    1975-01-01

    A leak detector for use with high vacuum seals as used in feedthroughs and hatch covers for manned spacecraft and vacuum systems is described. Two thermistors are used, one exposed directly to vacuum and the other exposed to a secondary chamber formed by the seal being monitored and a second auxiliary seal. Leakage into the secondary chamber causes an unbalance of an electrical bridge circuit in which the thermistors are connected.

  2. Insertion device vacuum system designs

    SciTech Connect

    Hoyer, E.

    1988-05-01

    Synchrotron light source insertion device vacuum systems now in operation and systems proposed for the future are reviewed. An overview of insertion devices is given and four generic vacuum chamber designs, transition section design and pumping considerations are discussed. Examples of vacuum chamber systems are presented.

  3. How reduced vacuum pumping capability in a coating chamber affects the laser damage resistance of HfO2/SiO2 antireflection and high-reflection coatings

    NASA Astrophysics Data System (ADS)

    Field, Ella S.; Bellum, John C.; Kletecka, Damon E.

    2015-11-01

    Optical coatings with the highest laser damage thresholds rely on clean conditions in the vacuum chamber during the coating deposition process. A low base pressure in the coating chamber, as well as the ability of the vacuum system to maintain the required pressure during deposition, are important aspects of limiting the amount of defects in an optical coating that could induce laser damage. Our large optics coating chamber at Sandia National Laboratories normally relies on three cryo pumps to maintain low pressures for e-beam coating processes. However, on occasion, one or more of the cryo pumps have been out of commission. In light of this circumstance, we decided to explore how deposition under compromised vacuum conditions resulting from the use of only one or two cryo pumps affects the laser-induced damage thresholds of optical coatings. The coatings of this study consist of HfO2 and SiO2 layer materials and include antireflection coatings for 527 nm at normal incidence, and high reflection coatings for 527 nm, 45° angle of incidence (AOI), in P-polarization (P-pol).

  4. All-Metal Antiaromaticity in Sb4 -Type Lanthanocene Anions.

    PubMed

    Min, Xue; Popov, Ivan A; Pan, Fu-Xing; Li, Lei-Jiao; Matito, Eduard; Sun, Zhong-Ming; Wang, Lai-Sheng; Boldyrev, Alexander I

    2016-04-25

    Antiaromaticity, as introduced in 1965, usually refers to monocyclic systems with 4n π electrons. This concept was extended to all-metal molecules after the observation of Li3 Al4 (-) in the gas phase. However, the solid-phase counterparts have not been documented to date. Herein, we describe a series of all-metal antiaromatic anions, [Ln(η(4) -Sb4 )3 ](3-) (Ln=La, Y, Ho, Er, Lu), which were isolated as the K([2.2.2]crypt) salts and identified by single-crystal X-ray diffraction. Based on the results obtained from the chemical bonding analysis, multicenter indices, and the electron-counting rule, we conclude that the core [Ln(η(4) -Sb4 )3 ](3-) fragment of the crystal has three locally π-antiaromatic Sb4 fragments. This complex represents the first locally π-antiaromatic all-metal system in the solid state, which is stabilized by interactions of the three π-antiaromatic units with the central metal atom. PMID:27062366

  5. Evacuated optical structure comprising optical bench mounted to sidewall of vacuum chamber in a manner which inhibits deflection and rotation of the optical bench

    DOEpatents

    Bowers, J.M.

    1994-04-19

    An improved evacuated optical structure is disclosed comprising an optical bench mounted in a vacuum vessel in a manner which inhibits transmission of movement of the vacuum vessel to the optical bench, yet provides a compact and economical structure. The vacuum vessel is mounted, through a sidewall thereof, to a support wall at four symmetrically positioned and spaced apart areas, each of which comprises a symmetrically positioned group of mounting structures passing through the sidewall of the vacuum vessel. The optical bench is pivotally secured to the vacuum vessel by four symmetrically spaced apart bolts and spherical bearings, each of which is centrally positioned within one of the four symmetrically positioned groups of vacuum vessel mounting structures. Cover plates and o-ring seals are further provided to seal the vacuum vessel mounting structures from the interior of the vacuum vessel, and venting bores are provided to vent trapped gases in the bores used to secure the cover plates and o-rings to the vacuum vessel. Provision for detecting leaks in the mounting structures from the rear surface of the vacuum vessel sidewall facing the support wall are also provided. Deflection to the optical bench within the vacuum vessel is further minimized by tuning the structure for a resonant frequency of at least 100 Hertz. 10 figures.

  6. Evacuated optical structure comprising optical bench mounted to sidewall of vacuum chamber in a manner which inhibits deflection and rotation of the optical bench

    DOEpatents

    Bowers, Joel M.

    1994-01-01

    An improved evacuated optical structure is disclosed comprising an optical bench mounted in a vacuum vessel in a manner which inhibits transmission of movement of the vacuum vessel to the optical bench, yet provides a compact and economical structure. The vacuum vessel is mounted, through a sidewall thereof, to a support wall at four symmetrically positioned and spaced apart areas, each of which comprises a symmetrically positioned group of mounting structures passing through the sidewall of the vacuum vessel. The optical bench is pivotally secured to the vacuum vessel by four symmetrically spaced apart bolts and spherical bearings, each of which is centrally positioned within one of the four symmetrically positioned groups of vacuum vessel mounting structures. Cover plates and o-ring seals are further provided to seal the vacuum vessel mounting structures from the interior of the vacuum vessel, and venting bores are provided to vent trapped gases in the bores used to secure the cover plates and o-rings to the vacuum vessel. Provision for detecting leaks in the mounting structures from the rear surface of the vacuum vessel sidewall facing the support wall are also provided. Deflection to the optical bench within the vacuum vessel is further minimized by tuning the structure for a resonant frequency of at least 100 Hertz.

  7. Multi-chamber deposition system

    DOEpatents

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-10-17

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  8. Multi-chamber deposition system

    DOEpatents

    Jacobson, Richard L.; Jeffrey, Frank R.; Westerberg, Roger K.

    1989-06-27

    A system for the simultaneous deposition of different coatings onto a thin web within a large volume vacuum chamber is disclosed which chamber is provided with a plurality of deposition chambers in which the different layers are deposited onto the film as its moves from a supply roll to a finished take-up roll of coated web. The deposition chambers provided within the large vacuum chamber are provided with separate seals which minimize back diffusion of any dopant gas from adjacent deposition chambers.

  9. All Metal Iron Core For A Low Aspect Ratio Tokamak

    SciTech Connect

    D.A. Gates, C. Jun, I. Zatz, A. Zolfaghari

    2010-06-02

    A novel concept for incorporating a iron core transformer within a axisymmetric toroidal plasma containment device with a high neutron flux is described. This design enables conceptual design of low aspect ratio devices which employ standard transformer-driven plasma startup by using all-metal high resistance separators between the toroidal field windings. This design avoids the inherent problems of a multiturn air core transformer which will inevitably suffer from strong neutron bombardment and hence lose the integrity of its insulation, both through long term material degradation and short term neutron- induced conductivity.. A full 3-dimensional model of the concept has been developed within the MAXWELL program and the resultant loop voltage calculated. The utility of the result is found to be dependent on the resistivity of the high resistance separators. Useful loop voltage time histories have been obtained using achievable resistivities.

  10. The Mobile Chamber

    NASA Technical Reports Server (NTRS)

    Scharfstein, Gregory; Cox, Russell

    2012-01-01

    A document discusses a simulation chamber that represents a shift from the thermal-vacuum chamber stereotype. This innovation, currently in development, combines the capabilities of space simulation chambers, the user-friendliness of modern-day electronics, and the modularity of plug-and-play computing. The Mobile Chamber is a customized test chamber that can be deployed with great ease, and is capable of bringing payloads at temperatures down to 20 K, in high vacuum, and with the desired metrology instruments integrated to the systems control. Flexure plans to lease Mobile Chambers, making them affordable for smaller budgets and available to a larger customer base. A key feature of this design will be an Apple iPad-like user interface that allows someone with minimal training to control the environment inside the chamber, and to simulate the required extreme environments. The feedback of thermal, pressure, and other measurements is delivered in a 3D CAD model of the chamber's payload and support hardware. This GUI will provide the user with a better understanding of the payload than any existing thermal-vacuum system.

  11. Radial-directed fluid-pressure-loaded all-metal-sealed gate valve

    DOEpatents

    Batzer, Thomas H.

    1992-01-01

    A large diameter gate valve uses a radially directed fluid pressure loaded all metal seal formed by engaging and disengaging a fixed and a moveable seal element. The fixed element is formed of a circular flange which contains a pressure chamber with a deformable wall, and is mounted to the valve body. The moving seal element contains an annular recess which mates with the circular flange, and is carried on a moveable sub-frame which moves on a frame fixed in the valve body. The valve opening defines an axis in a first direction, and the sub-frame moves through the valve body in a second direction which is substantially perpendicular to the first direction. The sub-frame and moveable seal element move in the second direction until the moveable element reaches a stop mounted in the valve body at which position the moveable element is aligned with but spaced apart from the fixed element. As the sub-frame continues to move in the second direction, the moveable element is forced to move toward and engage the fixed element. The pressure chamber in the flange is then pressurized to complete the seal.

  12. All-metal, compact heat exchanger for space cryocoolers

    NASA Technical Reports Server (NTRS)

    Swift, Walter L.; Valenzuela, Javier; Sixsmith, Herbert

    1990-01-01

    This report describes the development of a high performance, all metal compact heat exchanger. The device is designed for use in a reverse Brayton cryogenic cooler which provides five watts of refrigeration at 70 K. The heat exchanger consists of a stainless steel tube concentrically assembled within a second stainless steel tube. Approximately 300 pairs of slotted copper disks and matching annular slotted copper plates are positioned along the centerline axis of the concentric tubes. Each of the disks and plates has approximately 1200 precise slots machined by means of a special electric discharge process. Positioning of the disk and plate pairs is accomplished by means of dimples in the surface of the tubes. Mechanical and thermal connections between the tubes and plate/disk pairs are made by solder joints. The heat exchanger assembly is 9 cm in diameter by 50 cm in length and has a mass of 10 kg. The predicted thermal effectiveness is greater than 0.985 at design conditions. Pressure loss at design conditions is less than 5 kPa in both fluid passages. Tests were performed on a subassembly of plates integrally soldered to two end headers. The measured thermal effectiveness of the test article exceeded predicted levels. Pressure losses were negligibly higher than predictions.

  13. Portable vacuum object handling device

    DOEpatents

    Anderson, Gordon H.

    1983-08-09

    The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object.

  14. A multipurpose ultra-high vacuum-compatible chamber for in situ X-ray surface scattering studies over a wide range of temperature and pressure environment conditions

    NASA Astrophysics Data System (ADS)

    Ferrer, P.; Rubio-Zuazo, J.; Heyman, C.; Esteban-Betegón, F.; Castro, G. R.

    2013-03-01

    A low/high temperature (60-1000K) and pressure (10-10-3x103 mbar) "baby chamber", specially adapted to the grazing-incidence X-ray scattering station, has been designed, developed and installed at the Spanish CRG BM25 SpLine beamline at European Synchrotron Radiation Facility. The chamber has a cylindrical form with 100 mm of diameter, built on a 360° beryllium nipple of 150 mm height. The UHV equipment and a turbo pump are located on the upper part of the chamber to leave a wide solid angle for exploring reciprocal space. The chamber features 4 CF16 and 5 CF40 ports for electrical feed through and leak valves, ion gun, etc. The heat exchanger is a customized compact LN2 (or LHe) continuous flow cryostat. The sample is mounted on a Mo support on the heat exchanger, which has in the back side a BORALECTRIC® Heater Elements. Experiments of surfaces/interfaces/ multilayer materials, thin films or single crystals in a huge variety of environments can be performed, also in situ studies of growth or evolution of the samples. Data measurement can be collected with a punctual and a bi-dimensional detector, being possible to simultaneously use them.

  15. Machine tests slow-speed sliding friction in high vacuum

    NASA Technical Reports Server (NTRS)

    Skyrus, J.; Wilkinson, C.

    1967-01-01

    Testing machine that operates without any lubrication of the machine elements within the vacuum chamber measures static friction and sliding friction at very low speeds. Moving parts are held to a minimum to simplify operation in the vacuum chamber.

  16. Design of a tritium-compatible vacuum pumping system for the Compact Ignition Tokamak

    SciTech Connect

    Haines, J.R.

    1987-01-01

    The conceptual design for the Compact Ignition Tokamak (CIT) vacuum pumping system features high-speed, magnetic-bearing turbomolecular pumps (TMPs), metal-sealed scroll pumps for roughing and backing, and all-metal valves and flange seals. Because the plasma chamber exhaust is handled in a throughput instead of hold-up fashion with no organic seal or lubricating materials exposed to the vacuum stream, inventories of tritium, which are vulnerable to release during an accident and which inhibit maintenance of the vacuum pumping equipment, are minimized. To achieve an initial base pressure of 1.3 /times/ 10/sup /minus/6/ Pa in the plasma chamber, the design includes a large vacuum pumping duct and multiple high-speed TMPs arranged in two stages. The design studies discussed in this paper examine the feasibility and cost impact of providing a low-tritium-inventory, easily maintained vacuum pumping system for a deuterium-tritium (D-T) burning tokamak. 7 refs., 3 figs., 2 tabs.

  17. REQUIREMENTS AND GUIDELINES FOR NSLS EXPERIMENTAL BEAM LINE VACUUM SYSTEMS-REVISION B.

    SciTech Connect

    FOERSTER,C.

    1999-05-01

    Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are used at various beam line locations so that the monochromator, mirror box or sample chamber may be used in a helium atmosphere or rough vacuum. The window separates ring vacuum from the environment of the downstream beam line components. The stored beam lifetime in the storage rings and the maintenance of desirable reflection properties of optical surfaces depend upon hydrocarbon-free, ultra-high vacuum systems. Storage ring vacuum systems will operate at pressures of {approximately} 1 x 10{sup {minus}10} Torr without beam and {approximately} 1 x 10{sup {minus}9} Torr with beam. Systems are free of hydrocarbons in the sense that no pumps, valves, etc. containing organics are used. Components are all-metal, chemically cleaned and bakeable. To the extent that beam lines share a common vacuum with the storage ring, the same criteria will hold for beam line components. The design philosophy for NSLS beam lines is to use all-metal, hydrocarbon-free front end components and recommend that experimenters use this approach for common vacuum hardware downstream of front

  18. Ellipsometer for measurement in ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Walter, H. U.; Weitzenkamp, L. A.; Peters, P. N.

    1976-01-01

    Ellipsometer, used with ultrahigh vacuum, allows measurement of varied angles of incidence. Vacuum chamber, directly incorporated into optical bench systems, allows varied angle measurements to be taken through same region of a window.

  19. Breakdown-Resistant RF Connectors for Vacuum

    NASA Technical Reports Server (NTRS)

    Caro, Edward R.; Bonazza, Walter J.

    1987-01-01

    Resilient inserts compensate for insulation shrinkage. Coaxial-cable connector for radio-frequency (RF) energy resists electrical breakdown in vacuum. Used on RF equipment in vacuum chambers as well as in spaceborne radar and communication gear.

  20. Apparatus For Metal/Inert-Gas Welding In Vacuum

    NASA Technical Reports Server (NTRS)

    Stocks, C. O.

    1994-01-01

    Metal/inert-gas welding-torch assembly operates in vacuum. Plasma generated in interior chamber and focused onto workpiece in vacuum. Pinch rollers feed wire to weld puddle. Controlled flow of plasma reduces dispersal in vacuum, preventing extinction.

  1. Vacuum leak detector and method

    DOEpatents

    Edwards, Jr., David

    1983-01-01

    Apparatus and method for detecting leakage in a vacuum system involves a moisture trap chamber connected to the vacuum system and to a pressure gauge. Moisture in the trap chamber is captured by freezing or by a moisture adsorbent to reduce the residual water vapor pressure therein to a negligible amount. The pressure gauge is then read to determine whether the vacuum system is leaky. By directing a stream of carbon dioxide or helium at potentially leaky parts of the vacuum system, the apparatus can be used with supplemental means to locate leaks.

  2. Vacuum Gas Tungsten Arc Welding

    NASA Technical Reports Server (NTRS)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  3. Degassing procedure for ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Moore, B. C.

    1979-01-01

    Calculations based on diffusion coefficients and degassing rates for stainless-steel vacuum chambers indicate that baking at lower temperatures for longer periods give lower ultimate pressures than rapid baking at high temperatures. Process could reduce pressures in chambers for particle accelerators, fusion reactors, material research, and other applications.

  4. Portable vacuum object handling device

    DOEpatents

    Anderson, G.H.

    1983-08-09

    The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object. 1 fig.

  5. K-130 Cyclotron vacuum system

    NASA Astrophysics Data System (ADS)

    Yadav, R. C.; Bhattacharya, S.; Bhole, R. B.; Roy, Anindya; Pal, Sarbajit; Mallik, C.; Bhandari, R. K.

    2012-11-01

    The vacuum system for K-130 cyclotron has been operational since 1977. It consists of two sub-systems, main vacuum system and beam line vacuum system. The main vacuum system is designed to achieve and maintain vacuum of about 1 × 10-6 mbar inside the 23 m3 volume of acceleration chamber comprising the Resonator tank and the Dee tank. The beam line vacuum system is required for transporting the extracted beam with minimum loss. These vacuum systems consist of diffusion pumps backed by mechanical pumps like roots and rotary pumps. The large vacuum pumps and valves of the cyclotron vacuum system were operational for more than twenty five years. In recent times, problems of frequent failures and maintenance were occurring due to aging and lack of appropriate spares. Hence, modernisation of the vacuum systems was taken up in order to ensure a stable high voltage for radio frequency system and the extraction system. This is required for efficient acceleration and transportation of high intensity ion beam. The vacuum systems have been upgraded by replacing several pumps, valves, gauges and freon units. The relay based control system for main vacuum system has also been replaced by PLC based state of the art control system. The upgraded control system enables inclusion of additional operational logics and safety interlocks into the system. The paper presents the details of the vacuum system and describes the modifications carried out for improving the performance and reliability of the vacuum system.

  6. Development of a high vacuum sample preparation system for helium mass spectrometer

    NASA Astrophysics Data System (ADS)

    Kumar, P.; Das, N. K.; Mallik, C.; Bhandari, R. K.

    2012-11-01

    A high vacuum sample preparation system for the 3He/4He ratio mass spectrometer (Helix SFT) has been developed to remove all the gaseous constituents excluding helium from the field gases. The sample preparation system comprises of turbo molecular pump, ion pump, zirconium getter, pipettes and vacuum gauges with controller. All these are fitted with cylindrical SS chamber using all metal valves. The field samples are initially treated with activated charcoal trap immersed in liquid nitrogen to cutoff major impurities and moisture present in the sample gas. A sample of 5 ml is collected out of this stage at a pressure of 10-2 mbar. This sample is subsequently purified at a reduced pressure of 10-7 mbar before it is injected into the ion source of the mass spectrometer. The sample pressure was maintained below 10-7 mbar with turbo molecular vacuum pumps and ion pumps. The sample gas passes through several getter elements and a cold finger with the help of manual high vacuum valves before it is fed to the mass spectrometer. Thus the high vacuum sample preparation system introduces completely clean, dry and refined helium sample to the mass spectrometer for best possible analysis of isotopic ratio of helium.

  7. Exposure chamber

    DOEpatents

    Moss, Owen R.; Briant, James K.

    1983-01-01

    An exposure chamber includes an imperforate casing having a fluid inlet at the top and an outlet at the bottom. A single vertical series of imperforate trays is provided. Each tray is spaced on all sides from the chamber walls. Baffles adjacent some of the trays restrict and direct the flow to give partial flow back and forth across the chambers and downward flow past the lowermost pan adjacent a central plane of the chamber.

  8. Automated Electrostatics Environmental Chamber

    NASA Technical Reports Server (NTRS)

    Calle, Carlos; Lewis, Dean C.; Buchanan, Randy K.; Buchanan, Aubri

    2005-01-01

    The Mars Electrostatics Chamber (MEC) is an environmental chamber designed primarily to create atmospheric conditions like those at the surface of Mars to support experiments on electrostatic effects in the Martian environment. The chamber is equipped with a vacuum system, a cryogenic cooling system, an atmospheric-gas replenishing and analysis system, and a computerized control system that can be programmed by the user and that provides both automation and options for manual control. The control system can be set to maintain steady Mars-like conditions or to impose temperature and pressure variations of a Mars diurnal cycle at any given season and latitude. In addition, the MEC can be used in other areas of research because it can create steady or varying atmospheric conditions anywhere within the wide temperature, pressure, and composition ranges between the extremes of Mars-like and Earth-like conditions.

  9. Welding space vacuum technology

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1991-01-01

    The objective was to assist the EH 42 Division in putting together a vacuum system that could attain the desired pressure and be large enough to accommodate the gas-metal arc (GMA) welding fixture apparatus. A major accomplishment was the design and fabrication of the controller/annunciator for the 4' by 8' system. It contains many safety features such as thermocouple set point relays that will only allow inlet and exit gas and vacuum valves to be operated at pre-selected system pressures, and a fail safe mode for power interruptions and operator mistakes. It is felt that significant progress was made in this research effort to weld in a vacuum environment. With continued efforts to increase the pump speeds for vacuum chambers and further studies on weld fixtures and gas inlet pressures, the NASA program will be successful.

  10. Vacuum force

    NASA Astrophysics Data System (ADS)

    Han, Yongquan

    2015-03-01

    To study on vacuum force, we must clear what is vacuum, vacuum is a space do not have any air and also ray. There is not exist an absolute the vacuum of space. The vacuum of space is relative, so that the vacuum force is relative. There is a certain that vacuum vacuum space exists. In fact, the vacuum space is relative, if the two spaces compared to the existence of relative vacuum, there must exist a vacuum force, and the direction of the vacuum force point to the vacuum region. Any object rotates and radiates. Rotate bend radiate- centripetal, gravity produced, relative gravity; non gravity is the vacuum force. Gravity is centripetal, is a trend that the objects who attracted wants to Centripetal, or have been do Centripetal movement. Any object moves, so gravity makes the object curve movement, that is to say, the radiation range curve movement must be in the gravitational objects, gravity must be existed in non vacuum region, and make the object who is in the region of do curve movement (for example: The earth moves around the sun), or final attracted in the form gravitational objects, and keep relatively static with attract object. (for example: objects on the earth moves but can't reach the first cosmic speed).

  11. Exposure chamber

    DOEpatents

    Moss, Owen R.

    1980-01-01

    A chamber for exposing animals, plants, or materials to air containing gases or aerosols is so constructed that catch pans for animal excrement, for example, serve to aid the uniform distribution of air throughout the chamber instead of constituting obstacles as has been the case in prior animal exposure chambers. The chamber comprises the usual imperforate top, bottom and side walls. Within the chamber, cages and their associated pans are arranged in two columns. The pans are spaced horizontally from the walls of the chamber in all directions. Corresponding pans of the two columns are also spaced horizontally from each other. Preferably the pans of one column are also spaced vertically from corresponding pans of the other column. Air is introduced into the top of the chamber and withdrawn from the bottom. The general flow of air is therefore vertical. The effect of the horizontal pans is based on the fact that a gas flowing past the edge of a flat plate that is perpendicular to the flow forms a wave on the upstream side of the plate. Air flows downwardly between the chamber walls and the outer edges of the pan. It also flows downwardly between the inner edges of the pans of the two columns. It has been found that when the air carries aerosol particles, these particles are substantially uniformly distributed throughout the chamber.

  12. LDCM TIRS: Cracking open the chamber

    NASA Video Gallery

    Engineers at Goddard Space Flight Center inspect and move the Thermal Infrared Sensor (TIRS) after two months of testing in the thermal vacuum chamber. TIRS completed its first round of thermal vac...

  13. National Ignition Facility Target Chamber

    SciTech Connect

    Wavrik, R W; Cox, J R; Fleming, P J

    2000-10-05

    On June 11, 1999 the Department of Energy dedicated the single largest piece of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL) in Livermore, California. The ten (10) meter diameter aluminum target high vacuum chamber will serve as the working end of the largest laser in the world. The output of 192 laser beams will converge at the precise center of the chamber. The laser beams will enter the chamber in two by two arrays to illuminate 10 millimeter long gold cylinders called hohlraums enclosing 2 millimeter capsule containing deuterium, tritium and isotopes of hydrogen. The two isotopes will fuse, thereby creating temperatures and pressures resembling those found only inside stars and in detonated nuclear weapons, but on a minute scale. The NIF Project will serve as an essential facility to insure safety and reliability of our nation's nuclear arsenal as well as demonstrating inertial fusion's contribution to creating electrical power. The paper will discuss the requirements that had to be addressed during the design, fabrication and testing of the target chamber. A team from Sandia National Laboratories (SNL) and LLNL with input from industry performed the configuration and basic design of the target chamber. The method of fabrication and construction of the aluminum target chamber was devised by Pitt-Des Moines, Inc. (PDM). PDM also participated in the design of the chamber in areas such as the Target Chamber Realignment and Adjustment System, which would allow realignment of the sphere laser beams in the event of earth settlement or movement from a seismic event. During the fabrication of the target chamber the sphericity tolerances had to be addressed for the individual plates. Procedures were developed for forming, edge preparation and welding of individual plates. Construction plans were developed to allow the field construction of the target chamber to occur parallel to other NIF construction activities. This was

  14. Wire chamber

    DOEpatents

    Atac, Muzaffer

    1989-01-01

    A wire chamber or proportional counter device, such as Geiger-Mueller tube or drift chamber, improved with a gas mixture providing a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor.

  15. Vacuum systems for the ILC helical undulator

    SciTech Connect

    Malyshev, O. B.; Scott, D. J.; Bailey, I. R.; Barber, D. P.; Baynham, E.; Bradshaw, T.; Brummitt, A.; Carr, S.; Clarke, J. A.; Cooke, P.; Dainton, J. B.; Ivanyushenkov, Y.; Malysheva, L. I.; Moortgat-Pick, G. A.; Rochford, J.; Department of Physics, University of Liverpool Oxford St. Liverpool L69 7ZE; Cockcroft Institute, Warrington WA4 4AD

    2007-07-15

    The International Linear Collider (ILC) positron source uses a helical undulator to generate polarized photons of {approx}10 MeV at the first harmonic. Unlike many undulators used in synchrotron radiation sources, the ILC helical undulator vacuum chamber will be bombarded by photons, generated by the undulator, with energies mostly below that of the first harmonic. Achieving the vacuum specification of {approx}100 nTorr in a narrow chamber of 4-6 mm inner diameter, with a long length of 100-200 m, makes the design of the vacuum system challenging. This article describes the vacuum specifications and calculations of the flux and energy of photons irradiating the undulator vacuum chamber and considers possible vacuum system design solutions for two cases: cryogenic and room temperature.

  16. All-metal structural color printing based on aluminum plasmonic metasurfaces.

    PubMed

    Li, Zhigang; Wang, Wei; Rosenmann, Daniel; Czaplewski, David A; Yang, Xiaodong; Gao, Jie

    2016-09-01

    An all-metal structural color printing platform based on aluminum plasmonic metasurfaces is proposed and demonstrated with high color performance using only a one-step etching process on aluminum surface. A wide visible color range is realized with the designed metallic square-shaped disk arrays by simply adjusting the geometrical parameters of the disk etching depth, disk width and unit cell period. The demonstrated all-metal microscale structural color printing on aluminum surface offers great potential for many practical color related applications. PMID:27607652

  17. IONIZATION CHAMBER

    DOEpatents

    Redman, W.C.; Shonka, F.R.

    1958-02-18

    This patent describes a novel ionization chamber which is well suited to measuring the radioactivity of the various portions of a wire as the wire is moved at a uniform speed, in order to produce the neutron flux traverse pattern of a reactor in which the wire was previously exposed to neutron radiation. The ionization chamber of the present invention is characterized by the construction wherein the wire is passed through a tubular, straight electrode and radiation shielding material is disposed along the wire except at an intermediate, narrow area where the second electrode of the chamber is located.

  18. Sealed vacuum canister and method for pick-up and containment of material

    DOEpatents

    Stoutenburgh, R.R.

    1996-02-13

    A vacuum canister is described including a housing with a sealed vacuum chamber having a predetermined vacuum pressure therein and a valve having a first port for fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material. The valve is operable between a first position to seal the vacuum chamber and retain the predetermined vacuum within the vacuum chamber, and a second position to access the vacuum chamber to permit vacuum fluid flow through the valve from the second port into the vacuum chamber. The vacuum canister, in the operation to pick up material with the valve in the second position, when the second port is located adjacent at least one of a fluid and a particulate material, is effective to displace through the valve at least one of a fluid and a particulate material into the housing. The vacuum canister is desirably suitable for picking up and containing hazardous material such as radioactive material, in which the vacuum canister includes a protective layer of lead having a predetermined thickness that is effective to shield radiation emitted from the radioactive material contained within the housing. Advantageously, the vacuum canister includes a vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber. 6 figs.

  19. Sealed vacuum canister and method for pick-up and containment of material

    DOEpatents

    Stoutenburgh, Roger R.

    1996-01-01

    A vacuum canister including a housing with a sealed vacuum chamber having a predetermined vacuum pressure therein and a valve having a first port for fluid communication with the vacuum chamber and a second port for receiving at least one of a fluid and a particulate material. The valve is operable between a first position to seal the vacuum chamber and retain the predetermined vacuum within the vacuum chamber, and a second position to access the vacuum chamber to permit vacuum fluid flow through the valve from the second port into the vacuum chamber. In operation of the vacuum canister to pick up material with the valve in the second position, when the second port is located adjacent at least one of a fluid and a particulate material, is effective to displace through the valve at least one of a fluid and a particulate material into the housing. The vacuum canister is desirably suitable for picking up and containing hazardous material such as radioactive material, in which the vacuum canister includes a protective layer of lead having a predetermined thickness that is effective to shield radiation emitted from the radioactive material contained within the housing. Advantageously, the vacuum canister includes a vacuum means for establishing a predetermined vacuum pressure within the vacuum chamber.

  20. Vacuum Plasma Spraying Replaces Electrodeposition

    NASA Technical Reports Server (NTRS)

    Holmes, Richard R.; Power, Chris; Burns, David H.; Daniel, Ron; Mckechnie, Timothy N.

    1992-01-01

    Vacuum plasma spraying used to fabricate large parts with complicated contours and inner structures, without uninspectable welds. Reduces time, and expense of fabrication. Wall of combustion chamber built up inside of outer nickel-alloy jacket by plasma spraying. Particles of metal sprayed partially melted in plasma gun and thrown at supersonic speed toward deposition surface. Vacuum plasma-spray produces stronger bond between the grooves and covering layer completing channels and wall of combustion chamber. In tests, bond withstood pressure of 20 kpsi, three times allowable limit by old method.

  1. VACUUM TRAP AND VALVE COMBINATION

    DOEpatents

    Milleron, N.; Levenson, L.

    1963-02-19

    This patent relates to a vacuum trap and valve combination suitable for use in large ultra-high vacuum systems. The vacuum trap is a chamber having an inlet and outlet opening which may be made to communicate with a chamber to be evacuated and a diffusion pump, respectively. A valve is designed to hermeticaliy seal with inlet opening and, when opened, block the line-of- sight'' between the inlet and outlet openings, while allowing a large flow path between the opened vaive and the side walls of the trap. The interior of the trap and the side of the valve facing the inlet opening are covered with an impurity absorbent, such as Zeolite or activated aluminum. Besides the advantage of combining two components of a vacuum system into one, the present invention removes the need for a baffle between the pump and the chamber to be evacuated. In one use of a specific embodiment of this invention, the transmission probability was 45 and the partial pressure of the pump fluid vapor in the vacuum chamber was at least 100 times lower than its vapor pressure. (AEC)

  2. HESYRL storage ring vacuum system

    SciTech Connect

    Li, G.; Pang, Y.; Wang, Y.; Zhou, H.; Zhang, Z.; Jiang, D.; Xu, B.; Xu, S.

    1988-09-30

    The Storage Ring Vacuum System of the Synchrotron Radiation source project of HESYRL (Hefei Synchrotron Radiation Laboratory) in USTC, Hefei, Anhui, China, will be completed this year. Since the designed beam current of the 800 MeV electron storage ring is 300 mA, synchrotron radiation and hence high photon stimulated degassing will occur in the vacuum chamber. In order to get the stored beam lifetime of several hours, the pressure must be maintained at 10/sup -8/ approx.10/sup -9/ Torr. The gas desorption from synchrotron radiation and thermal outgas has been calculated. The UHV system of the storage ring and vacuum pretreatment methods are described in this paper.

  3. All-Metal-Waveguide Power Divider with High Power-Combining Efficiency

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Song, Kaijun; Fan, Maoyu; Fan, Yong

    2016-03-01

    A four-way all-metal-waveguide power divider has been presented and analyzed in this paper. A metal matching cylinder and a transition waveguide are applied to implement wide impedance matching from the input port to the four output ports. A simple equivalent-circuit model for this power-dividing structure has been developed. Moreover, the theoretical power-handling capability of the presented power-dividing structure has also been investigated. To verify the validity of the proposed structure, a four-way power divider at W-band has been fabricated with conventional machining. The measured return loss is greater than 14.5 dB from 82 GHz to 107 GHz. The measured insertion loss of the four-way all-metal-waveguide power divider is about 6.5 dB, which corresponds to a power-combining efficiency of 89 %.

  4. Ionization chamber

    DOEpatents

    Walenta, Albert H.

    1981-01-01

    An ionization chamber has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionize the gas.

  5. Ionization chamber

    DOEpatents

    Walenta, A.H.

    An ionization chamber is described which has separate drift and detection regions electrically isolated from each other by a fine wire grid. A relatively weak electric field can be maintained in the drift region when the grid and another electrode in the chamber are connected to a high voltage source. A much stronger electric field can be provided in the detection region by connecting wire electrodes therein to another high voltage source. The detection region can thus be operated in a proportional mode when a suitable gas is contained in the chamber. High resolution output pulse waveforms are provided across a resistor connected to the detection region anode, after ionizing radiation enters the drift region and ionizes the gas.

  6. Development of an all-metal thick film cost effective metallization system for solar cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1981-01-01

    The objectives of the investigation were to provide all-metal screenable pastes using economical base metals, suitable for application to low-to-high conductivity silicon of either conductivity type and possibly to aluminum surfaces. Experiments were conducted with variations in paste parameters, firing conditions, including gas ambients, furnace furniture, silicon surface and others. A liquid medium, intended to provide transport during the carbon fluoride decomposition was incorporated in the paste with promising results.

  7. Development of an all-metal thick film cost affective metallization system for solar cells

    NASA Technical Reports Server (NTRS)

    Ross, B.

    1981-01-01

    An economical thick film solar cell contact for high volume production of low cost silicon solar array modules was investigated. All metal screenable pastes using base metals were studied. Solar cells with junction depths varying by a factor of 3.3, with and without a deposited oxide coating were used. Cells were screened and fired by a two step firing process. Adhesion and metallurgical results are unsatisfactory. No electrical information is obtained due to inadequate contact adhesion.

  8. Development of an all-metal thick film cost effective metallization system for solar cells

    NASA Technical Reports Server (NTRS)

    Ross, B.; Parker, J.

    1983-01-01

    Improved thick film solar cell contacts for the high volume production of low cost silicon solar arrays are needed. All metal screenable pastes made from economical base metals and suitable for application to low to high conductivity silicon were examined. Silver fluoride containing copper pastes and fluorocarbon containing copper pastes were discussed. The effect of hydrogen on the adhesion of metals to silicon was investigated. A cost analysis of various paste materials is provided.

  9. VACUUM TRAP

    DOEpatents

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  10. Vacuum Technology

    SciTech Connect

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  11. Vacuum-insulated catalytic converter

    DOEpatents

    Benson, David K.

    2001-01-01

    A catalytic converter has an inner canister that contains catalyst-coated substrates and an outer canister that encloses an annular, variable vacuum insulation chamber surrounding the inner canister. An annular tank containing phase-change material for heat storage and release is positioned in the variable vacuum insulation chamber a distance spaced part from the inner canister. A reversible hydrogen getter in the variable vacuum insulation chamber, preferably on a surface of the heat storage tank, releases hydrogen into the variable vacuum insulation chamber to conduct heat when the phase-change material is hot and absorbs the hydrogen to limit heat transfer to radiation when the phase-change material is cool. A porous zeolite trap in the inner canister absorbs and retains hydrocarbons from the exhaust gases when the catalyst-coated substrates and zeolite trap are cold and releases the hydrocarbons for reaction on the catalyst-coated substrate when the zeolite trap and catalyst-coated substrate get hot.

  12. The LHC Vacuum System

    NASA Astrophysics Data System (ADS)

    Gröbner, O.

    1997-05-01

    The Large Hadron Collider (LHC) at CERN, involves two proton storage rings with colliding beams of 7 TeV. The machine will be housed in the existing LEP tunnel and requires 16 m long superconducting bending magnets. The vacuum chamber will be the inner wall of the cryostat and hence at the temperature of the magnet cold bore, i.e. at 1.9 K and therefore a very good cryo-pump. To reduce the cryogenic power consumption, the heat load from synchrotron radiation and from the image currents in the vacuum chamber will be absorbed on a 'beam screen', which operates between 5 and 20 K, inserted in the magnet cold bore. The design pressure necessary for operation must provide a lifetime of many days and a stringent requirement comes from the power deposition in the superconducting magnet coils due to protons scattered on the residual gas which could lead to a magnet quench. Cryo-pumping of gas on the cold surfaces provides the necessary low gas densities but it must be ensured that the vapour pressure of cryo-sorbed molecules, of which H2 and He would be the most critical species, remains within acceptable limits. The room temperature sections of the LHC, specifically in the experiments, the vacuum must be stable against ion induced desorption and ISR-type 'pressure bumps'.

  13. Vacuum test fixture improves leakage rate measurements

    NASA Technical Reports Server (NTRS)

    Maier, H.; Marx, H.

    1966-01-01

    Cylindrical chamber, consisting of two matching halves, forms a vacuum test fixture for measuring leakage rates of individual connections, brazed joints, and entrance ports used in closed fluid flow line systems. Once the chamber has been sufficiently evacuated, atmospheric pressure holds the two halves together.

  14. Pressure regulator with plastic vacuum fitting

    SciTech Connect

    Robinson, B.S.

    1994-01-04

    The vacuum control port at the control chamber of a fuel pressure regulator is an injection molded plastic member that can be formed with an angle. A flange is provided as a seating surface for an annular seal ring. The member extends into a tube formed in the regulator control chamber and is secured thereto. 3 figs.

  15. Vacuum Virtues

    ERIC Educational Resources Information Center

    Rathey, Allen

    2007-01-01

    Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

  16. Vacuum mechatronics

    NASA Technical Reports Server (NTRS)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  17. Test chamber for alpha spectrometry

    DOEpatents

    Larsen, Robert P.

    1977-01-01

    Alpha emitters for low-level radiochemical analysis by measurement of alpha spectra are positioned precisely with respect to the location of a surface-barrier detector by means of a chamber having a removable threaded planchet holder. A pedestal on the planchet holder holds a specimen in fixed engagement close to the detector. Insertion of the planchet holder establishes an O-ring seal that permits the chamber to be pumped to a desired vacuum. The detector is protected against accidental contact and resulting damage.

  18. Self contained, independent, in-vacuum spinner motor

    DOEpatents

    Ayers, Marion J.

    2002-01-01

    An independent, self contained apparatus for operation within a vacuum chamber. A sealed enclosure is located in the chamber. The enclosure contains its own atmosphere independent of the vacuum in the chamber. A motor, power unit, and controls are located entirely within the enclosure. They do not have a direct structural connection outside of the enclosure in any way that would effect the atmosphere within the enclosure. The motor, power unit, and controls drive a spinner plate located outside the enclosure but within the vacuum chamber.

  19. Magma chambers

    NASA Technical Reports Server (NTRS)

    Marsh, Bruce D.

    1989-01-01

    Recent observational and theoretical investigations of terrestrial magma chambers (MCs) are reviewed. Consideration is given to the evidence for MCs with active convection and crystal sorting, problems of direct MC detection, theoretical models of MC cooling, the rheology and dynamics of solidification fronts, crystal capture and differentiation, convection with solidification, MC wall flows, and MC roof melting. Diagrams, graphs, and a list of problems requiring further research are provided.

  20. Screenable all-metal solar cell electrodes of nickel and copper

    NASA Technical Reports Server (NTRS)

    Ross, B.; Bickler, D. B.

    1981-01-01

    Screenable thick film solar cell electrodes are made using the all-metal electrode system, which eliminates the commonly used glass frit and substitutes an oxide scavenger such as silver fluoride. The low temperature firing copper metal systems give good results on solar cells obtaining cell efficiencies of 13% AM1, and adhering sintered structures are demonstrated with nickel systems. The potential effect of copper upon cell performance at elevated temperatures over long periods of time is determined, and it is found that the formation of a copper-silicon eutectic at 550 C produces needle-like structures with broad bases on the silicon, extending into and occasionally through the metallization layer.

  1. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  2. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  3. Compact vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1993-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  4. Compact vacuum insulation embodiments

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1992-01-01

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially "point" or "line" contacts with the metal wall sheets. In the case of monolithic spacers that form "line" contacts, two such spacers with the line contacts running perpendicular to each other form effectively "point" contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  5. MEANS AND METHOD FOR PRODUCING A VACUUM

    DOEpatents

    Otavka, M.A.

    1960-08-01

    A new method is given for starting the operation of evapor-ion vacuum pumps. Ordinarily this type of pump is started by inducing an electric field with the vacuum chamber; however, by placing such an electric field in the chamber at the outset, a glow discharge may be initiated which is harmful to the pump. The procedure consists of using a negative electric field during which time only gettering action takes place; subsequently when the field reverses after a sufficient reduction of the number of gaseous particles in the chamber both gettering and ionizing takes place.

  6. Multipurpose Vacuum Induction Processing System

    NASA Astrophysics Data System (ADS)

    Govindaraju, M.; Kulkarni, Deepak; Balasubramanian, K.

    2012-11-01

    Multipurpose vacuum processing systems are cost effective; occupy less space, multiple functional under one roof and user friendly. A multipurpose vacuum induction system was designed, fabricated and installed in a record time of 6 months time at NFTDC Hyderabad. It was designed to function as a) vacuum induction melting/refining of oxygen free electronic copper/pure metals, b) vacuum induction melting furnace for ferrous materials c) vacuum induction melting for non ferrous materials d) large vacuum heat treatment chamber by resistance heating (by detachable coil and hot zone) e) bottom discharge vacuum induction melting system for non ferrous materials f) Induction heat treatment system and g) directional solidification /investment casting. It contains provision for future capacity addition. The attachments require to manufacture multiple shaped castings and continuous rod casting can be added whenever need arises. Present capacity is decided on the requirement for 10years of development path; presently it has 1.2 ton liquid copper handling capacity. It is equipped with provision for capacity addition up to 2 ton liquid copper handling capacity in future. Provision is made to carry out the capacity addition in easy steps quickly. For easy operational maintenance and troubleshooting, design was made in easily detachable sections. High vacuum system is also is detachable, independent and easily movable which is first of its kind in the country. Detailed design parameters, advantages and development history are presented in this paper.

  7. Vacuum arc deposition devices

    SciTech Connect

    Boxman, R.L.; Zhitomirsky, V.N.

    2006-02-15

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  8. Space Chambers for Crop Treatment

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Vacuum chambers, operated by McDonnell Douglas Corporation to test spacecraft, can also be used to dry water-soaked records. The drying temperature is low enough to allow paper to dry without curling or charging. Agricultural crops may also be dried using a spinoff system called MIVAC, which has proven effective in drying rice, wheat, soybeans, corn, etc. The system is energy efficient and can incorporate a sanitation process for destroying insects without contamination.

  9. ULTRA HIGH VACUUM VALVE

    DOEpatents

    Fry, W.A.

    1962-05-29

    A valve for high vacuum applications such as the CStellarator where chamber pressures as low as 2 x 10/sup -10/ mm Hg are necessary is designed with a line-of-sight path through the valve for visual inspection of the contents of reactants in such chambers. The valve comprises a turnable resilient metal ball having an aperture therethrough, means for selectively turning the ball to rotate the axis of its line-of-sight path, and soft, deformable opposing orifices that are movable relatively toward said ball to seal with opposite ball surfaces upon said movement of said axis of said line-of-sight path. The valve also includes a bellows seal connected between said orifices and internal actuating means that eliminates the requirement for gasketed turnable valve closing stems. (AEC)

  10. Re-circulating linac vacuum system

    SciTech Connect

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-05-09

    The vacuum system for a proposed 2.5 GeV, 10{Mu}A recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10{Mu}A average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing.

  11. 7 CFR 305.29 - Vacuum heat treatment schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Vacuum heat treatment schedule. 305.29 Section 305.29... SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.29 Vacuum heat treatment schedule. T111-a-1. Place bay leaves in a vacuum chamber. Starting at 0 hour, gradually reduce to 0.133...

  12. [Sb4Au4Sb4]2-: A designer all-metal aromatic sandwich

    NASA Astrophysics Data System (ADS)

    Tian, Wen-Juan; Guo, Jin-Chang; Li, Da-Zhi; You, Xue-Rui; Wang, Ying-Jin; Sun, Zhong-Ming; Zhai, Hua-Jin

    2016-07-01

    We report on the computational design of an all-metal aromatic sandwich, [Sb4Au4Sb4]2-. The triple-layered, square-prismatic sandwich complex is the global minimum of the system from Coalescence Kick and Minima Hopping structural searches. Following a standard, qualitative chemical bonding analysis via canonical molecular orbitals, the sandwich complex can be formally described as [Sb4]+[Au4]4-[Sb4]+, showing ionic bonding characters with electron transfers in between the Sb4/Au4/Sb4 layers. For an in-depth understanding of the system, one needs to go beyond the above picture. Significant Sb → Au donation and Sb ← Au back-donation occur, redistributing electrons from the Sb4/Au4/Sb4 layers to the interlayer Sb-Au-Sb edges, which effectively lead to four Sb-Au-Sb three-center two-electron bonds. The complex is a system with 30 valence electrons, excluding the Sb 5s and Au 5d lone-pairs. The two [Sb4]+ ligands constitute an unusual three-fold (π and σ) aromatic system with all 22 electrons being delocalized. An energy gap of ˜1.6 eV is predicted for this all-metal sandwich. The complex is a rare example for rational design of cluster compounds and invites forth-coming synthetic efforts.

  13. Theoretical investigation of all-metal-based mushroom plasmonic metamaterial absorbers at infrared wavelengths

    NASA Astrophysics Data System (ADS)

    Ogawa, Shinpei; Fujisawa, Daisuke; Kimata, Masafumi

    2015-12-01

    High-performance wavelength-selective infrared (IR) sensors require small pixel structures, a low-thermal mass, and operation in the middle-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) regions for multicolor IR imaging. All-metal-based mushroom plasmonic metamaterial absorbers (MPMAs) were investigated theoretically and were designed to enhance the performance of wavelength-selective uncooled IR sensors. All components of the MPMAs are based on thin layers of metals such as Au without oxide insulators for increased absorption. The absorption properties of the MPMAs were investigated by rigorous coupled-wave analysis. Strong wavelength-selective absorption is realized over a wide range of MWIR and LWIR wavelengths by the plasmonic resonance of the micropatch and the narrow-gap resonance, without disturbance from the intrinsic absorption of oxide insulators. The absorption wavelength is defined mainly by the micropatch size and is longer than its period. The metal post width has less impact on the absorption properties and can maintain single-mode operation. Through-holes can be formed on the plate area to reduce the thermal mass. A small pixel size with reduced thermal mass and wideband single-mode operation can be realized using all-metal-based MPMAs.

  14. An All-Metal Aromatic Sandwich Complex [Sb3Au3Sb3](3-).

    PubMed

    Pan, Fu-Xing; Li, Lei-Jiao; Wang, Ying-Jin; Guo, Jin-Chang; Zhai, Hua-Jin; Xu, Li; Sun, Zhong-Ming

    2015-09-01

    A sandwich complex, as exemplified by ferrocene in the 1950s, usually refers to one metal center bound by two arene ligands. The subject has subsequently been extended to carbon-free aromatic ligands and multiple-metal-atom "monolayered" center, but not to an all-metal species. Here, we describe the synthesis of an unprecedented all-metal aromatic sandwich complex, [Sb3Au3Sb3](3-), which was isolated as K([2.2.2]crypt)(+) salt and identified by single-crystal X-ray diffraction. Quantum chemical calculations indicate that intramolecular electron transfers for the three metallic layers (Sb → Au donation and Sb ← Au back-donation) markedly redistribute the valence electrons from the cyclo-Sb3 ligands and Au3 interlayer to the Au-Sb bonds, which hold the complex together via σ bonding. Each cyclo-Sb3 possesses aromaticity with delocalized three-center three-electron (3c-3e) π bonds, which are essentially equivalent to a 3c-4e ππ* triplet system, following the reversed 4n Hückel rule for aromaticity in a triplet state. PMID:26275027

  15. An all-metallic logic gate based on current-driven domain wall motion.

    PubMed

    Xu, Peng; Xia, Ke; Gu, Changzhi; Tang, Ling; Yang, Haifang; Li, Junjie

    2008-02-01

    The walls of magnetic domains can become trapped in a ferromagnetic metallic point contact when the thickness of the film and the width of the contact are less than their critical values. The discovery that domain walls can be moved from such constrictions by a sufficiently large current has attracted considerable attention from researchers working on both fundamental research and potential applications. Here we show that Invar nanocontacts fabricated on silica substrates exhibit a sharp drop in resistance with increasing bias voltage at room temperature in the absence of an applied magnetic field. Moreover, when two nanocontacts are combined in an all-metallic comparison circuit, it is possible to perform logical NOT operations. The use of electrical currents rather than applied magnetic fields to control the domain walls also reduces energy consumption and the risk of crosstalk in devices. PMID:18654469

  16. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    NASA Astrophysics Data System (ADS)

    Pacheco-Peña, V.; Torres, V.; Orazbayev, B.; Beruete, M.; Navarro-Cía, M.; Sorolla, M.; Engheta, N.

    2014-12-01

    An all-metallic steerable beam antenna composed of an ɛ-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ0 = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE10 mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°.

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  20. DC photogun vacuum characterization through photocathode lifetime studies

    SciTech Connect

    Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

    2007-07-02

    Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated.

  1. Ultra-high vacuum force, low air consumption pumps

    SciTech Connect

    Lasto, C.S.

    1989-11-14

    This patent describes a multi stage ejector assembly. It includes a solid elongate housing, a longitudinal cylindrical bore through the housing comprising a first venturi pump having a first converging-diverging venturi inlet nozzle opening through a first vacuum chamber in the cylindrical bore into the converging entrance of a first exit passage which opens through a second vacuum chamber into a second vacuum chamber into a second exit passage communicating with an outlet end of the cylindrical bore, first and second transverse bores inwardly from a side of the housing and each opening into the cylindrical bore at the first vacuum chamber, and a third transverse bore inwardly from a side of the housing and opening into the cylindrical bore at the second vacuum chamber. The first transverse bore comprising a second venturi pump having a second venturi inlet nozzle having an air flow consumption which is from about 5 to 15 times smaller than the air flow consumption of the first venturi inlet nozzle. The second venturi inlet nozzle opening through a maximum vacuum chamber into a converging-diverging venturi exit passage which opens into the cylindrical bore at the first vacuum chamber of the first venturi pump adjacent the converging entrance of the first exit passage.

  2. Plasma-surface interaction issues of an all-metal ITER

    NASA Astrophysics Data System (ADS)

    Brooks, J.N.; Allain, J.P.; Doerner, R.P.; Hassanein, A.; Nygren, R.; Rognlien, T.D.; Whyte, D.G.

    2009-03-01

    We assess key plasma-surface interaction issues of an all-metal plasma facing component (PFC) system for ITER, in particular a tungsten divertor, and a beryllium or tungsten first wall. Such a system eliminates problems with carbon divertor erosion and T/C codeposition, and for an all-tungsten system would better extrapolate to post-ITER devices. The issues studied are sputtering, transport and formation of mixed surface layers, tritium codeposition, plasma contamination, edge-localized mode (ELM) response and He-on-W irradiation effects. Code package OMEGA computes PFC sputtering erosion/redeposition in an ITER full power D-T plasma with convective edge transport. The HEIGHTS package analyses plasma transient response. PISCES and other data are used with code results to assess PFC performance. Predicted outer-wall sputter erosion rates are acceptable for Be (0.3 nm s-1) or bare (stainless steel/Fe) wall (0.05 nm s-1) for the low duty factor ITER, and are very low (0.002 nm s-1) for W. T/Be codeposition in redeposited wall material could be significant (~2 gT/400 s-ITER pulse). Core plasma contamination from wall sputtering appears acceptable for Be (~2%) and negligible for W (or Fe). A W divertor has negligible sputter erosion, plasma contamination and T/W codeposition. Be can grow at/near the strike point region of a W divertor, but for the predicted maximum surface temperature of ~800 °C, deleterious Be/W alloy formation as well as major He/W surface degradation will probably be avoided. ELMs are a serious challenge to the divertor, but this is true for all materials. We identify acceptable ELM parameters for W. We conclude that an all-metal PFC system is likely a much better choice for ITER D-T operation than a system using C. We discuss critical R&D needs, testing requirements, and suggest employing a 350-400 °C baking capability for T/Be reduction and using a deposited tungsten first wall test section.

  3. Optical testing cryogenic thermal vacuum facility

    NASA Astrophysics Data System (ADS)

    Dohogne, Patrick W.; Carpenter, Warren A.

    1990-11-01

    The construction of a turnkey cryogenic vacuum test facility was recently completed. The facility will be used to measure and record the surface profile of large diameter and 540 kg optics under simulated space conditions. The vacuum test chamber is a vertical stainless steel cylinder with a 3.5 diameter and a 7 m tangent length. The chamber was designed to maximize optical testing quality by minimizing the vibrations between the laser interferometer and the test specimen. This was accomplished by designing the chamber for a high natural frequency and vibration isolating the chamber. An optical test specimen is mounted on a movable presentation stage. During thermal vacuum testing, the specimen may be positioned to + or - 0.00025 cm accuracy with a fine adjustment mechanism. The chamber is evacuated by a close coupled Roots-type blower and rotary vane pump package and two cryopumps. The chamber is equipped with an optically dense gaseous nitrogen cooled thermal shroud. The thermal shroud is used to cool or warm the optical test specimen at a controlled rate. A control system is provided to automatically evacuate the chamber and cooldown the test specimen to the selected control temperature.

  4. Optical testing cryogenic thermal vacuum facility

    NASA Technical Reports Server (NTRS)

    Dohogne, Patrick W.; Carpenter, Warren A.

    1990-01-01

    The construction of a turnkey cryogenic vacuum test facility was recently completed. The facility will be used to measure and record the surface profile of large diameter and 540 kg optics under simulated space conditions. The vacuum test chamber is a vertical stainless steel cylinder with a 3.5 diameter and a 7 m tangent length. The chamber was designed to maximize optical testing quality by minimizing the vibrations between the laser interferometer and the test specimen. This was accomplished by designing the chamber for a high natural frequency and vibration isolating the chamber. An optical test specimen is mounted on a movable presentation stage. During thermal vacuum testing, the specimen may be positioned to + or - 0.00025 cm accuracy with a fine adjustment mechanism. The chamber is evacuated by a close coupled Roots-type blower and rotary vane pump package and two cryopumps. The chamber is equipped with an optically dense gaseous nitrogen cooled thermal shroud. The thermal shroud is used to cool or warm the optical test specimen at a controlled rate. A control system is provided to automatically evacuate the chamber and cooldown the test specimen to the selected control temperature.

  5. DETAIL OF VACUUM PIPE AT BASEMENT LEVEL OF O&C BUILDING, ...

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

    DETAIL OF VACUUM PIPE AT BASEMENT LEVEL OF O&C BUILDING, ALTITUDE CHAMBER R, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Altitude Chambers, First Street, between Avenue D and Avenue E, Cape Canaveral, Brevard County, FL

  6. Surface-adaptable all-metal micro-four-point probe with unique configuration

    NASA Astrophysics Data System (ADS)

    Kim, J. K.; Choi, Y. S.; Lee, D. W.

    2015-07-01

    In this paper, we propose a surface-adaptable all-metal micro-four-point probe (μ4PP) with a unique configuration. The μ4PP consists of four independent metallic sub-cantilevers with sharp Cu tips, and an SU-8 body structure to support the sub-cantilevers. The tip height is approximately 15 μm, and the tips are fabricated by anisotropic wet-etching of silicon followed by Cu electroplating. Each metallic cantilever connected to the SU-8 body structure acts as a flexible spring, so that the conducting tip can make gentle, non-destructive contact with fragile surfaces. To enhance the adhesion between the metallic sub-cantilevers and the SU-8 body, mushroom-shaped Cu structures were fabricated using an under-baked and under-exposed photolithography process. Various μ4PPs were designed and fabricated to verify their diverse range of applications, and preliminary experiments were performed using these fabricated μ4PPs. The resultant flexibility and reliability were experimentally confirmed on several samples, such as a polymer cantilever, a graphene flake, and curved metallic surfaces. We also expect that the proposed μ4PP will be suitable for measuring the anisotropic characteristics of crystal materials or the Hall effect in semiconductors.

  7. 99. 99% Al/ 6063 Alloy Co-extruded beam chamber

    SciTech Connect

    Ishimaru, H.; Narushima, K.; Kanazawa, K.

    1988-09-30

    In an electron storage ring, synchrotron radiation causes stimulated gas desorption from the vacuum chamber wall. It raises the operating pressure far above the ultrahigh vacuum range needed for long beam lifetimes. In order to determine an ideal material for low dynamic gas desorption we have studied the properties of co-extruded 99.99%Al/ 6063 alloy. (AIP)

  8. SXLS Phase 2 vacuum system

    SciTech Connect

    Schuchman, J.C.; Chou, T.S.; Halama, H.; Hsieh, H.; Kim, T.; Pjerov, S.; Staicu, F.

    1991-01-01

    Phase 1 of the SXLS (Superconducting X-Ray Lithography Source) is described. It is a room temperature, racetrack-shaped electron storage ring, 8.5 meters in circumference. The Phase 2 design consists of replacing the two room temperature 180{degree} dipole magnets of Phase 1 with superconducting magnets. However, even though superconducting magnets are used, the vacuum chambers within them will operate at room temperature. The chambers are constructed as weldments and are made of INCONEL-625. They are bakeable to 150{degrees}C in-situ and incorporate nine photon beam ports. Each have built-in distributed sputter-ion pumps (DIP), non-evaporable getter (NEG) pumps, beam position monitors, and ion clearing electrodes. R D is underway to optimize the DIP, which much operate at 3.86 Tesla, and to develop a low photo yield coating or treatment for the internal surfaces of the chambers.

  9. Gas and plasma dynamics of RF discharge jet of low pressure in a vacuum chamber with flat electrodes and inside tube, influence of RF discharge on the steel surface parameters

    NASA Astrophysics Data System (ADS)

    Khristoliubova, V. I.; Kashapov, N. F.; Shaekhov, M. F.

    2016-06-01

    Researches results of the characteristics of the RF discharge jet of low pressure and the discharge influence on the surface modification of high speed and structural steels are introduced in the article. Gas dynamics, power and energy parameters of the RF low pressure discharge flow in the discharge chamber and the electrode gap are studied in the presence of the materials. Plasma flow rate, discharge power, the concentration of electrons, the density of RF power, the ion current density, and the energy of the ions bombarding the surface materials are considered for the definition of basic properties crucial for the process of surface modification of materials as they were put in the plasma jet. The influence of the workpiece and effect of products complex configuration on the RF discharge jet of low pressure is defined. The correlation of the input parameters of the plasma unit on the characteristics of the discharge is established.

  10. Theoretical Performance of Hydrogen-Oxygen Rocket Thrust Chambers

    NASA Technical Reports Server (NTRS)

    Sievers, Gilbert K.; Tomazic, William A.; Kinney, George R.

    1961-01-01

    Data are presented for liquid-hydrogen-liquid-oxygen thrust chambers at chamber pressures from 15 to 1200 pounds per square inch absolute, area ratios to approximately 300, and percent fuel from about 8 to 34 for both equilibrium and frozen composition during expansion. Specific impulse in vacuum, specific impulse, combustion-chamber temperature, nozzle-exit temperature, characteristic velocity, and the ratio of chamber-to-nozzle-exit pressure are included. The data are presented in convenient graphical forms to allow quick calculation of theoretical nozzle performance with over- or underexpansion, flow separation, and introduction of the propellants at various initial conditions or heat loss from the combustion chamber.

  11. Outgassing measurement of the aluminum alloy UHV chamber

    NASA Technical Reports Server (NTRS)

    Miyamoto, M.; Itoh, T.; Komaki, S.; Narushima, K.; Ishimaru, H.

    1986-01-01

    A large vacuum chamber (580 mm diameter) was fabricated from an aluminum alloy surface treated by a special process normally used on small chambers. The chamber was tested unbaked and baked at various temperatures, pressures, and holding periods. The chamber was filled with N2 gas, and the outgassing rate was measured after one hour. Then the ultimate pressure was measured. Outgassing rates for baked and unbaked groups were compared. It is concluded that the same surface treatment technique can be used on both large and small chambers produced by the same special extrusion process.

  12. THERMOCOUPLE VACUUM GAUGE

    DOEpatents

    Price, G.W.

    1954-08-01

    A protector device is described for use in controlling the pressure within a cyclotron. In particular, an electrical circuit functions to actuate a vacuum pump when a predetermined low pressure is reached and disconnect the pump when the pressure increases abcve a certain value. The principal feature of the control circuit lies in the use of a voltage divider network at the input to a relay control tube comprising two parallel, adjustable resistances wherein one resistor is switched into the circuit when the relay connects the pump to a power source. With this arrangement the relay is energized at one input level received from a sensing element within the cyclotron chamber and is de-energized when a second input level, representing the higher pressure limit, is reached.

  13. Designing an Active Target Test Projection Chamber

    NASA Astrophysics Data System (ADS)

    Koci, James; Tan Ahn Collaboration, Dr.; Nicolas Dixneuf Collaboration

    2015-10-01

    The development of instrumentation in nuclear physics is crucial for advancing our ability to measure the properties of exotic nuclei. One limitation of the use of exotic nuclei in experiment is their very low production intensities. Recently, detectors, called active-target dectectors, have been developed to address this issue. Active-target detectors use a gas medium to image charged-particle tracks that are emitted in nuclear reactions. Last semester, I designed a vacuum chamber to be used in developing Micro-Pattern Gas detectors that will upgrade the capabilities of an active-target detector called the Prototype AT-TPC. With the exterior of the chamber complete, I have now been using an electric field modeling program, Garfield, developed by CERN to design a field cage to be placed within the vacuum chamber. The field cage will be a box-like apparatus consisting of two parallel metal plates connected with a resistor chain and attached to wires wrapped between them. The cage will provide a uniform electric field within the chamber to drift electrons from nuclear reactions down to the detector in the bottom of the chamber. These signals are then amplified by a proportional counter, and the data is sent to a computer. For the long term, we would like to incorporate a Micro-Pattern Gas Detectors in the interior of the chamber and eventually use the AT-TPC to examine various nuclei. Dr. Ahn is my advising professor.

  14. Report of the Synchrotron Radiation Vacuum Workshop

    SciTech Connect

    Avery, R.T.

    1984-06-01

    The Synchrotron Radiation Vacuum Workshop was held to consider two vacuum-related problems that bear on the design of storage rings and beam lines for synchrotron radiation facilities. These problems are gas desorption from the vacuum chamber walls and carbon deposition on optical components. Participants surveyed existing knowledge on these topics and recommended studies that should be performed as soon as possible to provide more definitive experimental data on these topics. This data will permit optimization of the final design of the Advanced Light Source (ALS) and its associated beam lines. It also should prove useful for other synchrotron radiation facilities as well.

  15. Vacuum coupling of rotating superconducting rotor

    DOEpatents

    Shoykhet, Boris A.; Zhang, Burt Xudong; Driscoll, David Infante

    2003-12-02

    A rotating coupling allows a vacuum chamber in the rotor of a superconducting electric motor to be continually pumped out. The coupling consists of at least two concentric portions, one of which is allowed to rotate and the other of which is stationary. The coupling is located on the non-drive end of the rotor and is connected to a coolant supply and a vacuum pump. The coupling is smaller in diameter than the shaft of the rotor so that the shaft can be increased in diameter without having to increase the size of the vacuum seal.

  16. Experimental investigation of the effect of polymer matrices on polymer fibre optic oxygen sensors and their time response characteristics using a vacuum testing chamber and a liquid flow apparatus

    PubMed Central

    Chen, Rongsheng; Formenti, Federico; McPeak, Hanne; Obeid, Andrew N.; Hahn, Clive; Farmery, Andrew

    2016-01-01

    Very fast sensors that are able to track rapid changes in oxygen partial pressure (PO2) in the gas and liquid phases are increasingly required in scientific research – particularly in the life sciences. Recent interest in monitoring very fast changes in the PO2 of arterial blood in some respiratory failure conditions is one such example. Previous attempts to design fast intravascular electrochemical oxygen sensors for use in physiology and medicine have failed to meet the criteria that are now required in modern investigations. However, miniature photonic devices are capable of meeting this need. In this article, we present an inexpensive polymer type fibre-optic, oxygen sensor that is two orders of magnitude faster than conventional electrochemical oxygen sensors. It is constructed with biologically inert polymer materials and is both sufficiently small and robust for direct insertion in to a human artery. The sensors were tested and evaluated in both a gas testing chamber and in a flowing liquid test system. The results showed a very fast T90 response time, typically circa 20 ms when tested in the gas phase, and circa 100 ms in flowing liquid. PMID:26726286

  17. Vacuum vapor deposition

    NASA Technical Reports Server (NTRS)

    Poorman, Richard M. (Inventor); Weeks, Jack L. (Inventor)

    1995-01-01

    A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate.

  18. All-metal electride molecules CuAg@Ca7M (M = Be, Mg, and Ca) with multi-excess electrons and all-metal polyanions: molecular structures and bonding modes as well as large infrared nonlinear optical responses.

    PubMed

    He, Hui-Min; Li, Ying; Sun, Wei-Ming; Wang, Jia-Jun; Wu, Di; Zhong, Rong-Lin; Zhou, Zhong-Jun; Li, Zhi-Ru

    2016-02-14

    All-metal electride molecules, CuAg@Ca7M (M = Be, Mg and Ca), have been designed and researched in theory for the first time. In these molecules, a pull-push electron relay occurs. Unusually, the all-metal polyanions of fourfold negatively charged [Cu-Ag-Be/Mg](4-) and [Cu-Ag](4-) with 4 extra electrons gained from Ca atoms push the remaining valence electrons of the Ca atoms forming the multi-excess electrons (Ne = 10/12). Therefore, these molecules can be described as salt-like [(Ca(2+))7(CuAgM)(4-)] + 10e(-) (M = Be and Mg) and [(Ca(2+))8(CuAg)(4-)] + 12e(-). In these salt-like molecules, there are extraordinary covalent bonding modes, which include 2c-2e/3c-2e σ-bonding in the polyanions and the Ca(2+) cations sharing the diffuse multi-excess electrons. For an intriguing nonlinear optical (NLO) response, these all-metal electride molecules display large electronic first hyperpolarizabilities (β0), thus a new class of NLO molecules, all-metal electride NLO molecules, emerge. Moreover, it is also found that manipulating the atomic number and position of M is a new strategy to enhance β0. As a result, CuAg@Ca7Mg(1) exhibits a considerable β0 (1.43 × 10(4) au), which is 16 times the β0 sum of two isolated CuAg and Ca7Mg(1) subunits, and this deeply reveals the fundamental origin of the considerable β0, namely, the multi-excess electrons generated by the subunit interaction. These all-metal electride molecules have the infrared (IR) transparent region of 1.3-6 μm, and hence are new IR NLO molecules. In addition the electronic contribution, β0, the large effects of vibrations on the static first hyperpolarizabilities of these all-metal electride molecules are also estimated. Thus, this study opens the new research field of all-metal electride IR NLO molecules. PMID:26740006

  19. High throughput vacuum chemical epitaxy

    NASA Astrophysics Data System (ADS)

    Fraas, L. M.; Malocsay, E.; Sundaram, V.; Baird, R. W.; Mao, B. Y.; Lee, G. Y.

    1990-10-01

    We have developed a vacuum chemical epitaxy (VCE) reactor which avoids the use of arsine and allows multiple wafers to be coated at one time. Our vacuum chemical epitaxy reactor closely resembles a molecular beam epitaxy system in that wafers are loaded into a stainless steel vacuum chamber through a load chamber. Also as in MBE, arsenic vapors are supplied as reactant by heating solid arsenic sources thereby avoiding the use of arsine. However, in our VCE reactor, a large number of wafers are coated at one time in a vacuum system by the substitution of Group III alkyl sources for the elemental metal sources traditionally used in MBE. Higher wafer throughput results because in VCE, the metal-alkyl sources for Ga, Al, and dopants can be mixed at room temperature and distributed uniformly though a large area injector to multiple substrates as a homogeneous array of mixed element molecular beams. The VCE reactor that we have built and that we shall describe here uniformly deposits films on 7 inch diameter substrate platters. Each platter contains seven two inch or three 3 inch diameter wafers. The load chamber contains up to nine platters. The vacuum chamber is equipped with two VCE growth zones and two arsenic ovens, one per growth zone. Finally, each oven has a 1 kg arsenic capacity. As of this writing, mirror smooth GaAs films have been grown at up to 4 μm/h growth rate on multiple wafers with good thickness uniformity. The background doping is p-type with a typical hole concentration and mobility of 1 × 10 16/cm 3 and 350 cm 2/V·s. This background doping level is low enough for the fabrication of MESFETs, solar cells, and photocathodes as well as other types of devices. We have fabricated MESFET devices using VCE-grown epi wafers with peak extrinsic transconductance as high as 210 mS/mm for a threshold voltage of - 3 V and a 0.6 μm gate length. We have also recently grown AlGaAs epi layers with up to 80% aluminum using TEAl as the aluminum alkyl source. The Al

  20. Heavy-Workpiece Handler For Vacuum Plasma Spraying

    NASA Technical Reports Server (NTRS)

    Myers, William N.

    1991-01-01

    Handling device manipulates heavy, hollow workpiece for plasma spraying in vacuum chamber. Rotates and tilts workpiece, keeping it approximately perpendicular to plasma-spray nozzle, so nozzle deposits uniform layer on interior surface of workpiece. Accommodates workpieces as heavy as 1,000 pounds and compatible with heat and vacuum of spraying process.

  1. Vacuum aperture isolator for retroreflection from laser-irradiated target

    DOEpatents

    Benjamin, Robert F.; Mitchell, Kenneth B.

    1980-01-01

    The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.

  2. Miniature self-contained vacuum compatible electronic imaging microscope

    DOEpatents

    Naulleau, Patrick P.; Batson, Phillip J.; Denham, Paul E.; Jones, Michael S.

    2001-01-01

    A vacuum compatible CCD-based microscopic camera with an integrated illuminator. The camera can provide video or still feed from the microscope contained within a vacuum chamber. Activation of an optional integral illuminator can provide light to illuminate the microscope subject. The microscope camera comprises a housing with a objective port, modified objective, beam-splitter, CCD camera, and LED illuminator.

  3. Vacuum pipe for e/sup +/e/sup -/ interactions

    SciTech Connect

    Hoard, C.T.

    1982-10-01

    The design, fabrication and testing of the beryllium vacuum chamber within the Mark II detector at SLAC is described. The Be chamber encloses one interaction point of the PEP circulating ring and is a part of its beam pipe. The Be chamber is captured within the Secondary Vertex Detector (SVD), a drift chamber, which is in turn centered in the Mark II drift chamber. Both ends of the beryllium pipe are brazed to aluminum/stainless transitions for connection to stainless steel bellows. A concentric radiation-screen liner of titanium foil runs the full length of the beryllium pipe.

  4. Evaporant feed device facilitates flash vapor deposition process in vacuum

    NASA Technical Reports Server (NTRS)

    Hermann, W. A.; Stirn, R. J.

    1967-01-01

    Mechanism using a helix sequentially feeds prescribed amounts of metal charges into an evaporation boat used for flash vapor deposition of the evaporants onto a substrate in a vacuum chamber. The helix is advanced by external manual controls extending through sealed feed- through devices into the chamber wall.

  5. Using the Nova target chamber for high-yield targets

    SciTech Connect

    Pitts, J.H.

    1987-09-28

    The existing 2.2-m-radius Nova aluminum target chamber, coated and lined with boron-seeded carbon shields, is proposed for use with 1000-MJ-yield targets in the next laser facility. The laser beam and diagnostic holes in the target chamber are left open and the desired 10/sup -2/ Torr vacuum is maintained both inside and outside the target chamber; a larger target chamber room is the vacuum barrier to the atmosphere. The hole area available is three times that necessary to maintain a maximum fluence below 12 J/cm/sup 2/ on optics placed at a radius of 10 m. Maximum stress in the target chamber wall is 73 MPa, which complies with the intent of the ASME Pressure Vessel Code. However, shock waves passing through the inner carbon shield could cause it to comminute. We propose tests and analyses to ensure that the inner carbon shield survives the environment. 13 refs.

  6. Advanced technology application for combustion chamber concepts

    NASA Technical Reports Server (NTRS)

    Tygielski, Kathy S.

    1992-01-01

    NASA-Marshall is engaged in the development of an Advanced Main Combustion Chamber under the aegis of the Earth-to-Orbit Propulsion Technology Program. AMCC is to be a robust and highly reliable combustion-chamber prototype costing one-third as much as current designs of comparable performance; it will be associated with a reduction of fabrication time by one-half. Attention is presently given to the three component-manufacturing processes used: single-piece investment casting for the structural jacket and manifolds; vacuum plasma spraying, for the combustion liner, and an alternative, platelet-compounded liner.

  7. Determination of molecular contamination performance for space chamber tests

    NASA Technical Reports Server (NTRS)

    Scialdone, J. J.

    1973-01-01

    The limitations of chamber tests with regard to the molecular contamination of a spacecraft undergoing vacuum test were examined. The molecular flow conditions existing in the chamber and the parameters dictating the degree of contamination were analyzed. Equations and graphs were developed to show the fraction of molecules returning to the spacecraft out of those emitted and to show other chamber flow parameters as a function of chamber and spacecraft surface molecular pumping and geometric configuration. Type and location of instruments required to measure the outgassing, the degree of contamination, and the returning flows are also discussed.

  8. Vacuum phenomenon.

    PubMed

    Yanagawa, Youichi; Ohsaka, Hiromichi; Jitsuiki, Kei; Yoshizawa, Toshihiko; Takeuchi, Ikuto; Omori, Kazuhiko; Oode, Yasumasa; Ishikawa, Kouhei

    2016-08-01

    This article describes the theory of the formation of the vacuum phenomenon (VP), the detection of the VP, the different medical causes, the different locations of the presentation of the VP, and the differential diagnoses. In the human body, the cavitation effect is recognized on radiological studies; it is called the VP. The mechanism responsible for the formation of the VP is as follows: if an enclosed tissue space is allowed to expand as a rebound phenomenon after an external impact, the volume within the enclosed space will increase. In the setting of expanding volume, the pressure within the space will decrease. The solubility of the gas in the enclosed space will decrease as the pressure of the space decreases. Decreased solubility allows a gas to leave a solution. Clinically, the pathologies associated with the VP have been reported to mainly include the normal joint motion, degeneration of the intervertebral discs or joints, and trauma. The frequent use of CT for trauma patients and the high spatial resolution of CT images might produce the greatest number of chances to detect the VP in trauma patients. The VP is observed at locations that experience a traumatic impact; thus, an analysis of the VP may be useful for elucidating the mechanism of an injury. When the VP is located in the abdomen, it is important to include perforation of the digestive tract in the differential diagnosis. The presence of the VP in trauma patients does not itself influence the final outcome. PMID:27147527

  9. High power all-metal spin torque oscillator using full Heusler Co{sub 2}(Fe,Mn)Si

    SciTech Connect

    Seki, Takeshi Sakuraba, Yuya; Ueda, Masaki; Okura, Ryo; Takanashi, Koki; Arai, Hiroko; Imamura, Hiroshi

    2014-09-01

    We showed the high rf power (P{sub out}) emission from an all-metal spin torque oscillator (STO) with a Co{sub 2}Fe{sub 0.4}Mn{sub 0.6}Si (CFMS)/Ag/CFMS giant magnetoresistance (GMR) stack, which was attributable to the large GMR effect thanks to the highly spin-polarized CFMS. The oscillation spectra were measured by varying the magnetic field direction, and the perpendicular magnetic field was effective to increase P{sub out} and the Q factor. We simultaneously achieved a high output efficiency of 0.013%, a high Q of 1124, and large frequency tunability. CFMS-based all-metal STO is promising for overcoming the difficulties that conventional STOs are confronted with.

  10. All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

    SciTech Connect

    Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

    2014-01-21

    We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

  11. Preparation, verification, and operational control of a large space-environment-simulation chamber for contamination sensitive tests

    NASA Technical Reports Server (NTRS)

    Visentine, J. T.; Ogden, J. W.; Ritter, M. L.; Smith, C. F.

    1972-01-01

    A 2-year program to prepare chamber A at the NASA Manned Spacecraft Center for Apollo telescope mount thermal-vacuum tests is discussed. This program covers modification to existing chamber systems, the development of facility and chamber operating procedures, the selection of chamber cleaning and control methods, and the development and evaluation of diagnostic instrumentation. Extensive efforts to ensure a minimum contamination environment for the Apollo telescope mount test series are illustrated. Recent thermal-vacuum tests of this chamber at progressive stages of cleanliness have demonstrated the success achieved in reducing the particulate and molecular contamination levels of the basic chamber interior.

  12. Vacuum system design for the PEP-II B Factory High-Energy Ring

    SciTech Connect

    Perkins, C.; Bostic, D.; Daly, E.

    1994-06-01

    The design of the vacuum system for the PEP-II B Factory High-Energy Ring is reviewed. The thermal design and vacuum requirements are particularly challenging in PEP-II due to high stored beam currents up to 3.0 amps in 1658 bunches. The vacuum chambers for the HER arcs are fabricated by electron beam welding extruded copper sections up to 6 m long. Design of these chambers and the vacuum PumPing configuration is described with results from vacuum and thermal analyses.

  13. Feed-thru flange is useful in vacuum applications to cryogenic temperatures

    NASA Technical Reports Server (NTRS)

    Yager, S. P.

    1966-01-01

    Feed-thru flange seals inner and outer walls of high vacuum test chambers. It is used in vacuum applications at both cryogenic and higher than cryogenic temperatures. A damaged flange can still be used for partial vacuum, noncryogenic applications in conjunction with an appropriate rubber seal.

  14. On-Orbit Daytime Solar Heating Effects: A Comparison of Ground Chamber Arcing Results

    NASA Technical Reports Server (NTRS)

    Galofaro, J.; Vayner, B.; Ferguson, D.

    2004-01-01

    The purpose of the current experiment is to make direct comparisons between the arcing results obtained from the diffusion pumped vertical chamber and our newly renovated Teney vacuum chamber which is equipped with a cryogenic pump. Recall that the prior reported results obtained for the Vertical chamber were nominal at best, showing only a slight reduction in the arc rate after five heating cycles at the lower bias potentials and virtually no changes at high potential biases. It was concluded that the vertical chamber was unable to remove enough water vapor from the chamber to adequately test the arcing criterion. Because the cryo-pumped Teney chamber has a ten times better pumping speed, (40,000 liters per sec compared to 4,000 liters per sec for the diffusion pumped vertical chamber), a decision was made to retest that experiment in both the Teney and Vertical vacuum chambers. A comparison of the various data is presented with encouraging results.

  15. On Orbit Daytime Solar Heating Effects: A Comparison of Ground Chamber Arcing Results

    NASA Technical Reports Server (NTRS)

    Galofaro, J.; Vayner, B.; Ferguson, D.

    2004-01-01

    The purpose of the current experiment is to make direct comparisons between the arcing results obtained from the diffusion pumped vertical chamber and our newly renovated Teney vacuum chamber which is equipped with a cryogenic pump. Recall that the prior reported results obtained for the Vertical chamber were nominal at best, showing only a slight reduction in the arc rate after 5 heating cycles at the lower bias potentials and virtually no changes at high potential biases. It was concluded that the vertical chamber was unable to remove enough water vapor from the chamber to adequately test the arcing criterion. Because the cryo-pumped Teney chamber has a ten times better pumping speed, (40,000 liters per sec compared to 4,000 liters per sec for the diffusion pumped vertical chamber), a decision was made to retest that experiment in both the Teney and Vertical vacuum chambers. A comparison of the various data is presented with encouraging results.

  16. Demountable vacuum seals for fusion reactor applications

    SciTech Connect

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

    1987-10-16

    Demountable vacuum seals for fusion reactor applications must be compatible with the reactor environment, easily scalable, very reliable and readily maintained by remote handling methods. We are investigating gate valves as well as flanges in our efforts to provide such seals. They are all metal and scalable without becoming massive and require no axial fasteners. Preliminary tests on an initial 30 cm aluminum flange using no soft metal coatings or gaskets have given several vacuum tight closures. Weld fatigue of this preliminary design caused degradation of the seal with further cycling to leakage levels of 10/sup -6/ Tl/sec, which is acceptable with differential pumping for either valves or flanges. Additional flange pairs using slightly altered geometry, fabrication techniques, and seal plating materials will be tested and reported on.

  17. Two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1998-05-05

    A vertical two chamber reaction furnace is described. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 C and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  18. Two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1998-05-05

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  19. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, R.A.

    1986-05-15

    A material source replenishment device for use with a vacuum deposition apparatus is described. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  20. Source replenishment device for vacuum deposition

    DOEpatents

    Hill, Ronald A.

    1988-01-01

    A material source replenishment device for use with a vacuum deposition apparatus. The source replenishment device comprises an intermittent motion producing gear arrangement disposed within the vacuum deposition chamber. An elongated rod having one end operably connected to the gearing arrangement is provided with a multiarmed head at the opposite end disposed adjacent the heating element of the vacuum deposition apparatus. An inverted U-shaped source material element is releasably attached to the outer end of each arm member whereby said multiarmed head is moved to locate a first of said material elements above said heating element, whereupon said multiarmed head is lowered to engage said material element with the heating element and further lowered to release said material element on the heating element. After vaporization of said material element, second and subsequent material elements may be provided to the heating element without the need for opening the vacuum deposition apparatus to the atmosphere.

  1. Vacuum packaging technology for mass production of uncooled IRFPAs

    NASA Astrophysics Data System (ADS)

    Ito, Takuya; Tokuda, Takayuki; Kimata, Masafumi; Abe, Hideyuki; Tokashiki, Naotaka

    2009-05-01

    We developed vacuum packaging equipment and low-cost vacuum packaging technology for the mass production of uncooled IRFPAs. The equipment consists of two chambers with identical construction. Two-chamber architecture provides flexibility in the vacuum packaging process, so we can bake the components and achieve getter activation by heating, stem/cap soldering, and cap/window soldering in a series under high-vacuum conditions. Heaters and component-holding jigs are made of graphite to assure rapid and uniform heating to 500°C. The batch size is 27 if we choose a 15-mm diameter TO8 package and can be increased by enlarging the graphite heater area. We also developed a micro-vacuum gauge to evaluate the vacuum level in encapsulated packages. The operation principle of this vacuum gauge is based on thermal conduction by air molecules. It can be integrated in IRFPA chips since the fabrication process is compatible with that for IRFPAs. We encapsulated the vacuum gauges in TO8 packages with our vacuum packaging equipment, and confirmed that the pressure in fabricated packages is sufficiently low for high performance IRFPA operation (<< 1 Pa) with the micro-vacuum gauges.

  2. The GODDESS ionization chamber: developing robust windows

    NASA Astrophysics Data System (ADS)

    Blanchard, Rose; Baugher, Travis; Cizewski, Jolie; Pain, Steven; Ratkiewicz, Andrew; Goddess Collaboration

    2015-10-01

    Reaction studies of nuclei far from stability require high-efficiency arrays of detectors and the ability to identify beam-like particles, especially when the beam is a cocktail beam. The Gammasphere ORRUBA Dual Detectors for Experimental Structure Studies (GODDESS) is made up of the Oak Ridge-Rutgers University Barrel Array (ORRUBA) of silicon detectors for charged particles inside of the gamma-ray detector array Gammasphere. A high-rate ionization chamber is being developed to identify beam-like particles. Consisting of twenty-one alternating anode and cathode grids, the ionization chamber sits downstream of the target chamber and is used to measure the energy loss of recoiling ions. A critical component of the system is a thin and robust mylar window which serves to separate the gas-filled ionization chamber from the vacuum of the target chamber with minimal energy loss. After construction, windows were tested to assure that they would not break below the required pressure, causing harm to the wire grids. This presentation will summarize the status of the ionization chamber and the results of the first tests with beams. This work is supported in part by the U.S. Department of Energy and National Science Foundation.

  3. Fail-safe design for square vacuum-barrier windows

    SciTech Connect

    Campbell, J. H.; Steele, R. A.; Steele, W. A.; Suratwala, T. I

    1998-07-30

    Laser-induced damage on the tensile side of vacuum-barrier fused silica optics can result in catastrophic fracture. This fracture can lead to two possible modes of failure: a benign failure resulting in a slow air leak into the vacuum chamber or an implosion. In previous work, they measured fracture in round vacuum windows and lenses and proposed a fail-safe design that would insure the benign failure mode by fracturing into only two parts, thus eliminating the possibility of implosion. In this paper they extend the previous work to include square vacuum-barrier windows and lenses.

  4. Steady State Vacuum Ultraviolet Exposure Facility With Automated Calibration Capability

    NASA Technical Reports Server (NTRS)

    Stueber, Thomas J.; Sechkar, Edward A.; Dever, Joyce A.; Banks, Bruce A.

    2000-01-01

    NASA Glenn Research Center at Lewis Field designed and developed a steady state vacuum ultraviolet automated (SSVUVa) facility with in situ VUV intensity calibration capability. The automated feature enables a constant accelerated VUV radiation exposure over long periods of testing without breaking vacuum. This test facility is designed to simultaneously accommodate four isolated radiation exposure tests within the SSVUVa vacuum chamber. Computer-control of the facility for long, term continuous operation also provides control and recording of thermocouple temperatures, periodic recording of VUV lamp intensity, and monitoring of vacuum facility status. This paper discusses the design and capabilities of the SSVUVa facility.

  5. High vacuum facility for hydrazine thruster testing

    NASA Technical Reports Server (NTRS)

    Neary, Patrick F.

    1990-01-01

    An ongoing modification is described of a large vacuum chamber to accommodate the ignition of an arcjet hydrazine thruster while maintaining a vacuum level of 1 x 10(exp -5) torr or less. The vacuum facility consists of a 20 ft stainless steel vacuum tank with an internal LN2 shroud, four 35 in. cryopumps and an 8 in. turbopump. To maintain a vacuum level of 1 x 10(exp -5) torr or less, 900 sq ft of liquid helium (LHe) shroud surface was installed to maintain the vacuum level and pumping requirements. A vacuum level of 1 x 10(exp -5) torr or less will allow the hydrazine thrust to exit the thruster nozzle and radiate into a space type environment so that the plume flow field can be analyzed and compared to the analytical model density distribution profile. Some other arcjet thruster characteristics measured are the electromagnetic interference (EMI) and exhaust contamination. This data is used to evaluate if the arcjet thruster with its high specific impulse in comparison to current chemical propulsion thruster can be used for the next generation of communication satellites.

  6. Natural vacuum electronics

    NASA Technical Reports Server (NTRS)

    Leggett, Nickolaus

    1990-01-01

    The ambient natural vacuum of space is proposed as a basis for electron valves. Each valve is an electron controlling structure similiar to a vacuum tube that is operated without a vacuum sustaining envelope. The natural vacuum electron valves discussed offer a viable substitute for solid state devices. The natural vacuum valve is highly resistant to ionizing radiation, system generated electromagnetic pulse, current transients, and direct exposure to space conditions.

  7. Material-controlled dynamic vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1996-10-08

    A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

  8. Radiation-controlled dynamic vacuum insulation

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1995-01-01

    A compact vacuum insulation panel comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber that includes apparatus and methods for enabling and disabling, or turning "on" and "off" the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls.

  9. Material-controlled dynamic vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1996-10-08

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  10. Radiation-controlled dynamic vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1995-07-18

    A compact vacuum insulation panel is described comprising a chamber enclosed by two sheets of metal, glass-like spaces disposed in the chamber between the sidewalls, and a high-grade vacuum in the chamber that includes apparatus and methods for enabling and disabling, or turning ``on`` and ``off`` the thermal insulating capability of the panel. One type of enabling and disabling apparatus and method includes a metal hydride for releasing hydrogen gas into the chamber in response to heat, and a hydrogen grate between the metal hydride and the chamber for selectively preventing and allowing return of the hydrogen gas to the metal hydride. Another type of enabling and disabling apparatus and method includes a variable emissivity coating on the sheets of metal in which the emissivity is controllably variable by heat or electricity. Still another type of enabling and disabling apparatus and method includes metal-to-metal contact devices that can be actuated to establish or break metal-to-metal heat paths or thermal short circuits between the metal sidewalls. 25 figs.

  11. VINCI Altitude Simulation - Vacuum Chamber Design and Manufacturing

    NASA Astrophysics Data System (ADS)

    Delrez, C.; Collin, B.; Chisogne, J.-P.; Amestoy, S.; Hardouin, E.

    2004-08-01

    a motor driven trolley, a raising/lowering system, The purpose of this article is to describe the design, computation, production and installation of a Simplified altitude Simulation (SAS) package intended for the VINCI engine tests on the PF52bench. a duct for connection to the ejector, an engine ignition viewing system a drive and power supply assembly, a set of measuring instruments, The simulation is used to reconstitute at ground level the same flying conditions as those normally found at the altitude where the Ariane 5 launcher cryogenic engine is fired. a control and monitoring assembly. This PF52 bench, which is being modified, is located on the Snecma Moteurs Space Engine division's test site, at Vernon (France). The design, computation, production and installation of the SAS are under the responsibility of the company AMOS sa, at Angleur (Belgium).

  12. BAKABLE ULTRA-HIGH VACUUM VALVE

    DOEpatents

    Mark, J.T.; Gantz, I.H.

    1962-07-10

    S>This patent relates to a valve useful in applications involving successively closing and opening a communication between a chamber evacuated to an ultra-high vacuum condition of the order of 10/sup -10/ millimeters of mercury and another chamber or the ambient. The valve is capable of withstanding extended baking at 450 deg C and repeated opening and closing without repiacement of the valve seat (approximately 200 cycle limit). The seal is formed by mutual interdiffusion weld, coerced by a pneumatic actuator. (AEC)

  13. The RHIC vacuum systems

    NASA Astrophysics Data System (ADS)

    Burns, R.; Hseuh, H. C.; Lee, R. C.; McIntyre, G.; Pate, D.; Smart, L.; Sondericker, J.; Weiss, D.; Welch, K.

    2003-03-01

    There are three vacuum systems in RHIC: the insulating vacuum vessels housing the superconducting magnets, the cold beam tubes surrounded by the superconducting magnets, and the warm beam tube sections at the insertion regions and the experimental regions. These systems have a cumulative length over 10 km and a total volume over 3000 m 3. Conventional ultrahigh vacuum technology was used in the design and construction of the cold and warm beam vacuum systems with great success. The long and large insulating vacuum volumes without vacuum barriers require careful management of the welding and leak checking of the numerous helium line joints. There are about 1500 vacuum gauges and pumps serial-linked to eight PLCs distributed around RHIC, which allow the monitoring and control of these devices through Ethernet networks to remote control consoles. With the exception of helium leaks through the cryogenic valve boxes into the insulating vacuum volumes, the RHIC vacuum systems have performed well beyond expectations.

  14. Indian Vacuum Society: The Indian Vacuum Society

    NASA Astrophysics Data System (ADS)

    Saha, T. K.

    2008-03-01

    The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of

  15. Electron Backscatter Diffraction in Low Vacuum Conditions

    SciTech Connect

    El-Dasher, B S; Torres, S G

    2008-07-17

    Most current scanning electron microscopes (SEMs) have the ability to analyze samples in a low vacuum mode, whereby a partial pressure of water vapor is introduced into the SEM chamber, allowing the characterization of nonconductive samples without any special preparation. Although the presence of water vapor in the chamber degrades electron backscatter diffraction (EBSD) patterns, the potential of this setup for EBSD characterization of nonconductive samples is immense. In this chapter we discuss the requirements, advantages and limitations of low vacuum EBSD (LV-EBSD), and present how this technique can be applied to a two-phase ceramic composite as well as hydrated biominerals as specific examples of when LV-EBSD can be invaluable.

  16. All-Metal Tires

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.; Sword, Lee F.; Lindemann, Randel A.

    1994-01-01

    Tires used where elastomeric and pneumatic tires would not function. Metal tires withstand extreme temperatures. Used on Earth for vehicles and robots that fight fires or clean up dangerous chemicals.

  17. Polarization measurements in the vacuum ultraviolet

    NASA Astrophysics Data System (ADS)

    Kobayashi, K.; West, E. A.; Noble, M.

    2005-08-01

    This paper will describe the Vacuum Ultraviolet (VUV) polarization testing of the Solar Ultraviolet Magnetograph (SUMI) optics. SUMI is being develop for a sounding rocket payload to prove the feasibility of making magnetic field measurements in the transition region. This paper will cover the polarization properties of the VUV calibration polarizers, the instrumental polarization of the VUV chamber, SUMI's toroidal varied-line-space gratings and the SUMI polarimeter.

  18. Systems and methods for analyzing liquids under vacuum

    DOEpatents

    Yu, Xiao-Ying; Yang, Li; Cowin, James P.; Iedema, Martin J.; Zhu, Zihua

    2013-10-15

    Systems and methods for supporting a liquid against a vacuum pressure in a chamber can enable analysis of the liquid surface using vacuum-based chemical analysis instruments. No electrical or fluid connections are required to pass through the chamber walls. The systems can include a reservoir, a pump, and a liquid flow path. The reservoir contains a liquid-phase sample. The pump drives flow of the sample from the reservoir, through the liquid flow path, and back to the reservoir. The flow of the sample is not substantially driven by a differential between pressures inside and outside of the liquid flow path. An aperture in the liquid flow path exposes a stable portion of the liquid-phase sample to the vacuum pressure within the chamber. The radius, or size, of the aperture is less than or equal to a critical value required to support a meniscus of the liquid-phase sample by surface tension.

  19. Optimizing process vacuum condensers

    SciTech Connect

    Lines, J.R.; Tice, D.W.

    1997-09-01

    Vacuum condensers play a critical role in supporting vacuum processing operations. Although they may appear similar to atmospheric units, vacuum condensers have their own special designs, considerations and installation needs. By adding vacuum condensers, precondensers and intercondensers, system cost efficiency can be optimized. Vacuum-condensing systems permit reclamation of high-value product by use of a precondenser, or reduce operating costs with intercondensers. A precondenser placed between the vacuum vessel and ejector system will recover valuable process vapors and reduce vapor load to an ejector system--minimizing the system`s capital and operating costs. Similarly, an intercondenser positioned between ejector stages can condense motive steam and process vapors and reduce vapor load to downstream ejectors as well as lower capital and operating costs. The paper describes vacuum condenser systems, types of vacuum condensers, shellside condensing, tubeside condensing, noncondensable gases, precondenser pressure drop, system interdependency, equipment installation, and equipment layout.

  20. Target chambers for gammashpere

    SciTech Connect

    Carpenter, M.P.; Falout, J.W.; Nardi, B.G.

    1995-08-01

    One of our responsibilities for Gammasphere, was designing and constructing two target chambers and associated beamlines to be used with the spectrometer. The first chamber was used with the early implementation phase of Gammasphere, and consisted of two spun-Al hemispheres welded together giving a wall thickness of 0.063 inches and a diameter of 12 inches.

  1. Static diffusion cloud chambers

    NASA Technical Reports Server (NTRS)

    Ayers, G.

    1981-01-01

    The chamber geometry and optical arrangement are described. The supersaturation range is given and consists of readings taken at five fixed points: 0.25%, 0.5%, 0.75%, 1.0%, and 1.25%. The detection system is described including light source, cameras, and photocell detectors. The temperature control and the calibration of the chamber are discussed.

  2. High resolution drift chambers

    SciTech Connect

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 ..mu..m resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs.

  3. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-03-06

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  4. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E.

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  5. Contamination Control Assessment of the World's Largest Space Environment Simulation Chamber

    NASA Technical Reports Server (NTRS)

    Snyder, Aaron; Henry, Michael W.; Grisnik, Stanley P.; Sinclair, Stephen M.

    2012-01-01

    The Space Power Facility s thermal vacuum test chamber is the largest chamber in the world capable of providing an environment for space simulation. To improve performance and meet stringent requirements of a wide customer base, significant modifications were made to the vacuum chamber. These include major changes to the vacuum system and numerous enhancements to the chamber s unique polar crane, with a goal of providing high cleanliness levels. The significance of these changes and modifications are discussed in this paper. In addition, the composition and arrangement of the pumping system and its impact on molecular back-streaming are discussed in detail. Molecular contamination measurements obtained with a TQCM and witness wafers during two recent integrated system tests of the chamber are presented and discussed. Finally, a concluding remarks section is presented.

  6. The Classical Vacuum.

    ERIC Educational Resources Information Center

    Boyer, Timothy H.

    1985-01-01

    The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

  7. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    SciTech Connect

    Pacheco-Peña, V. Torres, V. Orazbayev, B. Beruete, M. Sorolla, M.; Navarro-Cía, M.; Engheta, N.

    2014-12-15

    An all-metallic steerable beam antenna composed of an ε-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ{sub 0} = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE{sub 10} mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°.

  8. A new oil-free mechanical vacuum pump

    NASA Astrophysics Data System (ADS)

    Bez, E.; Guarnaccia, D.; Hablanian, M.

    1988-09-01

    A number of entirely oil-free, four-stage reciprocating-piston vacuum pumps which produce an ultimate pressure of approximately 15 mTorr have been in operation for periods approaching two years. These pumps have been used for pre-evacuation of high and ultra-high vacuum chambers and devices, backing of turbomolecular pumps, molecular drag pumps and Roots-type blowers, regeneration of cryo-pumps, pumping of vacuum furnances and process chambers for degassing solids and liquids. Basic performance characteristics are generally similar to conventional mechanical vacuum pumps with a comparable ultimate pressure but with the advantage of being free of hydrocarbons in the residual gas content. Practical operational experience regarding longevity, maintenance requirements, inlet pressure, and power relationships are presented.

  9. Gas-controlled dynamic vacuum insulation with gas gate

    DOEpatents

    Benson, David K.; Potter, Thomas F.

    1994-06-07

    Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber.

  10. Gas-controlled dynamic vacuum insulation with gas gate

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1994-06-07

    Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber. 25 figs.

  11. A Road Map to Extreme High Vacuum

    SciTech Connect

    Myneni, Ganapati Rao

    2007-06-20

    Ultimate pressure of a well-designed vacuum system very much depends on pretreatments, processing and the procedures [1,2]. Until now much attention has been paid in minimizing hydrogen outgassing from the chamber material. However, procedures and processing deserves further scrutiny than hitherto given so far. For reducing the gas load, high sensitivity helium leak detection techniques with sensitivities better than 1× 10-12 Torr l/sec need to be used. Effects that are induced by vacuum instrumentation need to be reduced in order to obtain accurate pressure measurements. This presentation will discuss: clean assembly procedures, metal sponges for cryosorption pumping of hydrogen to extreme high vacuum, low cost surface diffusion barriers for reducing the hydrogen gas load, cascade pumping, sensitive helium leak detection techniques and the use of modified extractor and residual gas analyzers. Further, alternative back up pumping systems based on active NEG’s [3] for turbo molecular pumps will be presented.

  12. High vacuum measurements and calibrations, molecular flow fluid transient effects

    SciTech Connect

    Leishear, Robert A.; Gavalas, Nickolas A.

    2015-04-29

    High vacuum pressure measurements and calibrations below 1 × 10-8 Torr are problematic. Specifically, measurement accuracies change drastically for vacuum gauges when pressures are suddenly lowered in vacuum systems. How can gauges perform like this? A brief system description is first required to answer this question. Calibrations were performed using a vacuum calibration chamber with attached vacuum gauges. To control chamber pressures, vacuum pumps decreased the chamber pressure while nitrogen tanks increased the chamber pressure. By balancing these opposing pressures, equilibrium in the chamber was maintained at selected set point pressures to perform calibrations. When pressures were suddenly decreased during set point adjustments, a sudden rush of gas from the chamber also caused a surge of gas from the gauges to decrease the pressures in those gauges. Gauge pressures did not return to equilibrium as fast as chamber pressures due to the sparse distribution of gas molecules in the system. This disparity in the rate of pressure changes caused the pressures in different gauges to be different than expected. This discovery was experimentally proven to show that different gauge designs return to equilibrium at different rates, and that gauge accuracies vary for different gauge designs due to fluid transients in molecular flow.

  13. High vacuum measurements and calibrations, molecular flow fluid transient effects

    DOE PAGESBeta

    Leishear, Robert A.; Gavalas, Nickolas A.

    2015-04-29

    High vacuum pressure measurements and calibrations below 1 × 10-8 Torr are problematic. Specifically, measurement accuracies change drastically for vacuum gauges when pressures are suddenly lowered in vacuum systems. How can gauges perform like this? A brief system description is first required to answer this question. Calibrations were performed using a vacuum calibration chamber with attached vacuum gauges. To control chamber pressures, vacuum pumps decreased the chamber pressure while nitrogen tanks increased the chamber pressure. By balancing these opposing pressures, equilibrium in the chamber was maintained at selected set point pressures to perform calibrations. When pressures were suddenly decreased duringmore » set point adjustments, a sudden rush of gas from the chamber also caused a surge of gas from the gauges to decrease the pressures in those gauges. Gauge pressures did not return to equilibrium as fast as chamber pressures due to the sparse distribution of gas molecules in the system. This disparity in the rate of pressure changes caused the pressures in different gauges to be different than expected. This discovery was experimentally proven to show that different gauge designs return to equilibrium at different rates, and that gauge accuracies vary for different gauge designs due to fluid transients in molecular flow.« less

  14. 45. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION DDD), ...

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

    45. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION DDD), VIEW LOOKING EAST. LEAD ENCLOSED PIPING IS DRAIN FROM BOILER CHAMBER No. 1 - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  15. Vacuum plasma spray applications on liquid fuel rocket engines

    NASA Technical Reports Server (NTRS)

    Mckechnie, T. N.; Zimmerman, F. R.; Bryant, M. A.

    1992-01-01

    The vacuum plasma spray process (VPS) has been developed by NASA and Rocketdyne for a variety of applications on liquid fuel rocket engines, including the Space Shuttle Main Engine. These applications encompass thermal barrier coatings which are thermal shock resistant for turbopump blades and nozzles; bond coatings for cryogenic titanium components; wear resistant coatings and materials; high conductivity copper, NaRloy-Z, combustion chamber liners, and structural nickel base material, Inconel 718, for nozzle and combustion chamber support jackets.

  16. Vacuum plasma spray applications on liquid fuel rocket engines

    NASA Astrophysics Data System (ADS)

    McKechnie, T. N.; Zimmerman, F. R.; Bryant, M. A.

    1992-07-01

    The vacuum plasma spray process (VPS) has been developed by NASA and Rocketdyne for a variety of applications on liquid fuel rocket engines, including the Space Shuttle Main Engine. These applications encompass thermal barrier coatings which are thermal shock resistant for turbopump blades and nozzles; bond coatings for cryogenic titanium components; wear resistant coatings and materials; high conductivity copper, NaRloy-Z, combustion chamber liners, and structural nickel base material, Inconel 718, for nozzle and combustion chamber support jackets.

  17. Inertial confinement fusion reaction chamber and power conversion system study

    SciTech Connect

    Maya, I.; Schultz, K.R.; Battaglia, J.M.; Buksa, J.J.; Creedson, R.L.; Erlandson, O.D.; Levine, H.E.; Roelant, D.F.; Sanchez, H.W.; Schrader, S.A.

    1984-09-01

    GA Technologies has developed a conceptual ICF reactor system based on the Cascade rotating-bed reaction chamber concept. Unique features of the system design include the use of low activation SiC in a reaction chamber constructed of box-shaped tiles held together in compression by prestressing tendons to the vacuum chamber. Circulating Li/sub 2/O granules serve as the tritium breeding and energy transport material, cascading down the sides of the reaction chamber to the power conversion system. The total tritium inventory of the system is 6 kg; tritium recovery is accomplished directly from the granules via the vacuum system. A system for centrifugal throw transport of the hot Li/sub 2/O granules from the reaction chamber to the power conversion system has been developed. A number of issues were evaluated during the course of this study. These include the response of first-layer granules to the intense microexplosion surface heat flux, cost effective fabrication of Li/sub 2/O granules, tritium inventory and recovery issues, the thermodynamics of solids-flow options, vacuum versus helium-medium heat transfer, and the tradeoffs of capital cost versus efficiency for alternate heat exchange and power conversion system option. The resultant design options appear to be economically competitive, safe, and environmentally attractive.

  18. Diffraction-limited storage-ring vacuum technology

    PubMed Central

    Al-Dmour, Eshraq; Ahlback, Jonny; Einfeld, Dieter; Tavares, Pedro Fernandes; Grabski, Marek

    2014-01-01

    Some of the characteristics of recent ultralow-emittance storage-ring designs and possibly future diffraction-limited storage rings are a compact lattice combined with small magnet apertures. Such requirements present a challenge for the design and performance of the vacuum system. The vacuum system should provide the required vacuum pressure for machine operation and be able to handle the heat load from synchrotron radiation. Small magnet apertures result in the conductance of the chamber being low, and lumped pumps are ineffective. One way to provide the required vacuum level is by distributed pumping, which can be realised by the use of a non-evaporable getter (NEG) coating of the chamber walls. It may not be possible to use crotch absorbers to absorb the heat from the synchrotron radiation because an antechamber is difficult to realise with such a compact lattice. To solve this, the chamber walls can work as distributed absorbers if they are made of a material with good thermal conductivity, and distributed cooling is used at the location where the synchrotron radiation hits the wall. The vacuum system of the 3 GeV storage ring of MAX IV is used as an example of possible solutions for vacuum technologies for diffraction-limited storage rings. PMID:25177979

  19. An Environmental Chamber to Investigate Liquid Saline Water in the Martian Polar Region

    NASA Astrophysics Data System (ADS)

    Elliott, H. M.; Martinez, G. M.; Halleaux, D. G.; Braswell, S. F.; Renno, N. O.

    2012-04-01

    We present the design of an environmental chamber to simulate the diurnal and seasonal cycles of the Martian polar region. This chamber is being built to aid in the investigation of liquid saline water in Mars' Richardson Crater (72° S, 179° E) and the Mars Phoenix Lander site (68° N, 126° W). Our objective is to: (i) determine the environmental conditions at with brines, formed from perchlorate salts found by the Mars Phoenix Lander, are stable on the surface of Mars and (ii) determine the optical properties of liquid saline water flows hypothesized to exist in Mars' Richardson Crater. The environmental chamber system consists of a vacuum chamber with six internal thermal plates. The plates are arranged to form a cubic thermal cavity that can be cryogenically cooled by liquid nitrogen. Additional thermal control is attained through the use of resistive patch heaters, which are fixed on the thermal plates. The vacuum chamber inlet is connected to a carbon dioxide dry gas stream, which can be throttled to control the chamber's humidity. The vacuum chamber outlet passes through a chilled mirror hygrometer to measure the chamber humidity before the air exits the vacuum pump. Acknowledgements: This research is supported by a grant from the NASA Astrobiology Program: Exobiology and Evolutionary Biology. Award #09-EXOB09-0050. Keywords: Liquid Saline Water, Cryobrines, Richardson Crater, Mars Phoenix Lander

  20. The Mars Chamber

    NASA Video Gallery

    The Mars chamber is a box about the size of a refrigerator that re-creates the temperatures, pressures, and atmosphere of the Martian surface, essentially creating a Mars environment on Earth! Scie...

  1. Indian LSSC (Large Space Simulation Chamber) facility

    NASA Technical Reports Server (NTRS)

    Brar, A. S.; Prasadarao, V. S.; Gambhir, R. D.; Chandramouli, M.

    1988-01-01

    The Indian Space Agency has undertaken a major project to acquire in-house capability for thermal and vacuum testing of large satellites. This Large Space Simulation Chamber (LSSC) facility will be located in Bangalore and is to be operational in 1989. The facility is capable of providing 4 meter diameter solar simulation with provision to expand to 4.5 meter diameter at a later date. With such provisions as controlled variations of shroud temperatures and availability of infrared equipment as alternative sources of thermal radiation, this facility will be amongst the finest anywhere. The major design concept and major aspects of the LSSC facility are presented here.

  2. Upgrade of The Thermal Vacuum Data System at NASA/GSFC

    NASA Technical Reports Server (NTRS)

    Palmer, John; Powers, Edward I. (Technical Monitor)

    2000-01-01

    The Goddard Space Flight Center's new thermal vacuum data acquisition system is a networked client-sever application that enables lab operations crews to monitor all tests from a central location. The GSFC thermal vacuum lab consists of eleven chambers in Building 7 and one chamber in Building 10. The new data system was implemented for several reasons. These included the need for centralized data collection, more flexible and easier to use operator interface, greater data accessibility, a reduction in testing time and cost, and increased payload and personnel safety. Additionally, a new data system was needed for year-2000 compliance. This paper discusses the incorporation of the Thermal Vacuum Data System (TVDS) within the thermal vacuum lab at GSFC, its features and capabilities and lessons learned in its implementation. Additional topics include off-center (Internet) capability for remote monitoring and the role of TVDS in the efforts to automate thermal vacuum chamber operations.

  3. Upgrade of the Thermal Vacuum Data System at NASA/GSFC

    NASA Technical Reports Server (NTRS)

    Palmer, John

    2000-01-01

    The Goddard Space Flight Center's new thermal vacuum data acquisition system is a networked client-sever application that enables lab operations crews to monitor all tests from a central location. The GSFC thermal vacuum lab consists of eleven chambers in Building 7 and one chamber in Building 10. The new data system was implemented for several reasons. These included the need for centralized data collection, more flexible and easier to use operator interface, greater data accessibility, a reduction in testing time and cost, and increased payload and personnel safety. Additionally, a new data system was needed for year-2000 compliance. This paper discusses the incorporation of the Thermal Vacuum Data System (TVDS) within the thermal vacuum lab at GSFC, its features and capabilities and lessons learned in its implementation. Additional topics include off-center (Internet) capability for remote monitoring and the role of TVDS in the efforts to automate thermal vacuum chamber operations.

  4. Sleeve reaction chamber system

    SciTech Connect

    Northrup, M. Allen; Beeman, Barton V.; Benett, William J.; Hadley, Dean R.; Landre, Phoebe; Lehew, Stacy L.; Krulevitch, Peter A.

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  5. Target area chamber system design for the National Ignition Facility

    SciTech Connect

    Wavrik, R.; Boyes, J.; Olson, C.; Dempsey, F.; Garcia, R.; Karpenko, V.; Anderson, A.; Tobin, M.; Latkowski, J.

    1994-06-01

    The National Ignition Facility (NIF) is a proposed Department of Energy facility which will contribute to the resolution of important Defense Program and inertial fusion energy issues for energy production in the future. The NIF will consist of a laser system with 192 independent beamlets transported to a target chamber. The target chamber is a multi-purpose structure that provides the interface between the target and the laser optics. The chamber must be capable of achieving moderate vacuum levels in reasonable times; it must remain dimensionally stable within micron tolerances, provide support for the optics, diagnostics, and target positioner; it must minimize the debris from the x-ray and laser light environments; and it must be capable of supporting external neutron shielding. The chamber must also be fabricated from a low activation material. The fusion reaction in the target gives off neutrons, x-ray and gamma rays. The x-rays and gamma rays interact with the interior of the target chamber wall while neutrons penetrate the wall. In order to minimize the neutron activation of components outside the target chamber and to absorb gammas emitted from the activated chamber, shielding will be placed immediately outside the chamber. The target chamber contains the target positioner. The target positioner moves the target from outside the chamber to the center of the chamber and positions the target at the focal spot of the laser beams. The target positioner must be survivable in a harsh radioactive environment. The materials used must be low activation and have a high stiffness to weight ratio to maintain target stability. This paper describes the conceptual design of the target chamber, target postioner, and shielding for the NIF.

  6. Slat Heater Boxes for Thermal Vacuum Testing

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene

    2003-01-01

    Slat heater boxes have been invented for controlling the sink temperatures of objects under test in a thermal vacuum chamber, the walls of which are cooled to the temperature of liquid nitrogen. A slat heater box (see Figure 1) includes a framework of struts that support electrically heated slats that are coated with a high-emissivity optically gray paint. The slats can be grouped together into heater zones for the purpose of maintaining an even temperature within each side. The sink temperature of an object under test is defined as the steady-state temperature of the object in the vacuum/ radiative environment during the absence of any internal heat source or sink. The slat heater box makes it possible to closely control the radiation environment to obtain a desired sink temperature. The slat heater box is placed inside the cold thermal vacuum chamber, and the object under test is placed inside (but not in contact with) the slat heater box. The slat heaters occupy about a third of the field of view from any point on the surface of the object under test, the remainder of the field of view being occupied by the cold chamber wall. Thus, the radiation environment is established by the combined effects of the slat heater box and the cold chamber wall. Given (1) the temperature of the chamber wall, (2) the fractions of the field of view occupied by the chamber wall and the slat heater box, and (3) the emissivities of the slats, chamber wall, and the surface of object under test, the slat temperature required to maintain a desired sink temperature can be calculated by solving the equations of gray-body radiation for the steady-state adiabatic case (equal absorption and emission by the object under test). Slat heater boxes offer an important advantage over the infrared lamps that have been previously used to obtain desired sink temperatures: In comparison with an infrared lamp, a slat heater box provides a greater degree of sink temperature uniformity for a test

  7. Vacuum system for the Synchrotron X-ray Source at Argonne

    SciTech Connect

    Wehrle, R.; Moenich, J.; Kim, S.; Nielsen, R.

    1987-01-01

    The vacuum system of the APS storage ring is designed to maintain a beam-on operating pressure of 1 nTorr or less in order to achieve a positron beam lifetime of approximately 20 hours. The vacuum chamber is an aluminum extrusion containing a beam chamber and antechamber. The primary source of the pumping is with NeG strips. The design and location of the crotches and strip absorbers are based on the distribution of the bending magnet synchrotron radiations.

  8. Design and discovery of a novel half-Heusler transparent hole conductor made of all-metallic heavy elements.

    PubMed

    Yan, Feng; Zhang, Xiuwen; Yu, Yonggang G; Yu, Liping; Nagaraja, Arpun; Mason, Thomas O; Zunger, Alex

    2015-01-01

    Transparent conductors combine two generally contradictory physical properties, but there are numerous applications where both functionalities are crucial. Previous searches focused on doping wide-gap metal oxides. Focusing instead on the family of 18 valence electron ternary ABX compounds that consist of elements A, B and X in 1:1:1 stoichiometry, we search theoretically for electronic structures that simultaneously lead to optical transparency while accommodating intrinsic defect structures that produce uncompensated free holes. This leads to the prediction of a stable, never before synthesized TaIrGe compound made of all-metal heavy atom compound. Laboratory synthesis then found it to be stable in the predicted crystal structure and p-type transparent conductor with a strong optical absorption peak at 3.36 eV and remarkably high hole mobility of 2,730 cm(2) V(-1) s(-1) at room temperature. This methodology opens the way to future searches of transparent conductors in unexpected chemical groups. PMID:26106063

  9. All-aluminum-alloy UHV chamber for molecular beam epitaxy, 1

    NASA Astrophysics Data System (ADS)

    Suemitsu, M.; Miyamoto, N.

    1984-03-01

    The first all aluminum alloy (ex. JIS.6263-t6,2219-t87 etc) MBE chamber is constructed and described. After exposure to atmosphere, the chamber is drown to 10(-9) torr in 24 hours, and reaches an ultrahigh vacuum of 1.6x10(-10) torr by a 115 C, 24 bakeout process. The light weight and low cost as well as the short pump-down time and the law outgassing rate of the all aluminum alloy vacuum system seems to have a considerable applicative potentiality for equipment used in semiconductor ultrahigh vacuum processes.

  10. Vacuum pump aids ejectors

    SciTech Connect

    Nelson, R.E.

    1982-12-01

    The steam ejector/vacuum pump hybrid system has been operating satisfactorily since the summer of 1981. This system has essentially been as troublefree as the all-ejector system and, of course, has provided a substantial cost savings. Construction is currently under way to convert the vacuum system of another crude still which is equipped with steam ejectors and barometric condensers to the hybrid system of steam ejectors, surface condensers, and vacuum pumps. This current project is even more financially attractive because it allows a dirty water cooling tower which serves the barometric condensers to be shut down. Providing a vacuum for crude distillation vacuum towers with this hybrid system is by no means the only application of this technique. Any vacuum system consisting of all steam ejectors would be a candidate for this hybrid system and the resulting savings in energy.

  11. Overview of High Power Vacuum Dry RF Load Designs

    SciTech Connect

    Krasnykh, Anatoly

    2015-08-27

    A specific feature of RF linacs based on the pulsed traveling wave (TW) mode of operation is that only a portion of the RF energy is used for the beam acceleration. The residual RF energy has to be terminated into an RF load. Higher accelerating gradients require higher RF sources and RF loads, which can stably terminate the residual RF power. RF feeders (from the RF source though the accelerating section to the load) are vacuumed to transmit multi-megawatt high power RF. This overview will outline vacuumed RF loads only. A common method to terminate multi-MW RF power is to use circulated water (or other liquid) as an absorbing medium. A solid dielectric interface (a high quality ceramic) is required to separate vacuum and liquid RF absorber mediums. Using such RF load approaches in TW linacs is troubling because there is a fragile ceramic window barrier and a failure could become catastrophic for linac vacuum and RF systems. Traditional loads comprising of a ceramic disk have limited peak and average power handling capability and are therefore not suitable for high gradient TW linacs. This overview will focus on ''vacuum dry'' or ''all-metal'' loads that do not employ any dielectric interface between vacuum and absorber. The first prototype is an original design of RF loads for the Stanford Two-Mile Accelerator.

  12. Main Vacuum Technical Issues of Evacuated Tube Transportation

    NASA Astrophysics Data System (ADS)

    Zhang, Y. P.; Li, S. S.; Wang, M. X.

    In the future, Evacuated Tube Transportation (ETT) would be built and faster than jets. ETT tube with diameter 2∼4m and length over 1000 km will be the largest scale vacuum equipment on earth. This paper listed some main vacuum technical issues to be solved in ETT as follow. How to build ultra-large-scale vacuum chamber like ETT tube with low cost and high reliability? How to pump gas out off the ETT tube in short time? How to release heat or reduce temperature in the vacuum tube? Hot to avoid vacuum electricity discharge? How to manufacture vehicles with airproof shells and equip the life support system? How to detect leakage and find leakage position efficiently and fast as possible? Some relative solutions and suggestions are put up.

  13. Vacuum probe surface sampler

    NASA Technical Reports Server (NTRS)

    Zahlava, B. A. (Inventor)

    1973-01-01

    A vacuum probe surface sampler is described for rapidly sampling relatively large surface areas which possess relatively light loading densities of micro-organism, drug particles or the like. A vacuum head with a hollow handle connected to a suitable vacuum source is frictionally attached to a cone assembly terminating in a flared tip adapted to be passed over the surface to be sampled. A fine mesh screen carried by the vacuum head provides support for a membrane filter which collects the microorganisms or other particles. The head assembly is easily removed from the cone assembly without contacting the cone assembly with human hands.

  14. Improved Rhenium Thrust Chambers

    NASA Technical Reports Server (NTRS)

    O'Dell, John Scott

    2015-01-01

    Radiation-cooled bipropellant thrust chambers are being considered for ascent/ descent engines and reaction control systems on various NASA missions and spacecraft, such as the Mars Sample Return and Orion Multi-Purpose Crew Vehicle (MPCV). Currently, iridium (Ir)-lined rhenium (Re) combustion chambers are the state of the art for in-space engines. NASA's Advanced Materials Bipropellant Rocket (AMBR) engine, a 150-lbf Ir-Re chamber produced by Plasma Processes and Aerojet Rocketdyne, recently set a hydrazine specific impulse record of 333.5 seconds. To withstand the high loads during terrestrial launch, Re chambers with improved mechanical properties are needed. Recent electrochemical forming (EL-Form"TM") results have shown considerable promise for improving Re's mechanical properties by producing a multilayered deposit composed of a tailored microstructure (i.e., Engineered Re). The Engineered Re processing techniques were optimized, and detailed characterization and mechanical properties tests were performed. The most promising techniques were selected and used to produce an Engineered Re AMBR-sized combustion chamber for testing at Aerojet Rocketdyne.

  15. Apparatus Measures Friction In Vacuum Or Pressurized Gas

    NASA Technical Reports Server (NTRS)

    Trevathan, Joseph R.

    1996-01-01

    Friction-testing apparatus in small test chamber contains special atmosphere, which could include vacuum or pressurized gas. Provides readings indicative of friction between pin specimen and plate specimen sliding under pin in reciprocating linear motion. Pin and plate specimens made of same or different material.

  16. Apparatus facilitates high-temperature tensile testing in vacuum

    NASA Technical Reports Server (NTRS)

    Sikora, P. F.

    1964-01-01

    An apparutus for heating refractory materials to high temperatures during tensile testing includes a water-cooled stainless steel vacuum chamber. This contains a resistance heater consisting of a slit tube of tantalum or tungsten to enclose the tensile test rod.

  17. Working in a Vacuum

    ERIC Educational Resources Information Center

    Rathey, Allen

    2005-01-01

    In this article, the author discusses several myths about vacuum cleaners and offers tips on evaluating and purchasing this essential maintenance tool. These myths are: (1) Amps mean performance; (2) Everyone needs high-efficiency particulate air (HEPA): (3) Picking up a "bowling ball" shows cleaning power; (4) All vacuum bags are the same; (5)…

  18. Vacuum system for the LBL Advanced Light Source (ALS)

    SciTech Connect

    Kennedy, K.; Henderson, T.; Meneghetti, J. )

    1989-03-01

    A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit most synchrotron photons to escape the electron channel and be absorbed in an antechamber. The gas generated by the photons hitting the absorbers in the antechambers will be pumped by titanium sublimation pumps located directly under the absorbers. The electron channel and the antechamber are connected by a 10-mm-high slot that offers good electrodynamic isolation of the two chambers of frequencies affecting the store electron orbit. Twelve 10-meter-long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. Machining both the inside and outside of the vacuum chamber permits the use of complex and accurate surfaces. The use of thick plates allows flanges to be machined directly into the wall of each chamber, thus avoiding much welding. 1 ref., 3 figs.

  19. Filament wound rocket motor chambers

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The design, analysis, fabrication and testing of a Kevlar-49/HBRF-55A filament wound chamber is reported. The chamber was fabricated and successfully tested to 80% of the design burst pressure. Results of the data reduction and analysis from the hydrotest indicate that the chamber design and fabrication techniques used for the chamber were adequate and the chamber should perform adequately in a static test.

  20. Automated soil gas monitoring chamber

    DOEpatents

    Edwards, Nelson T.; Riggs, Jeffery S.

    2003-07-29

    A chamber for trapping soil gases as they evolve from the soil without disturbance to the soil and to the natural microclimate within the chamber has been invented. The chamber opens between measurements and therefore does not alter the metabolic processes that influence soil gas efflux rates. A multiple chamber system provides for repetitive multi-point sampling, undisturbed metabolic soil processes between sampling, and an essentially airtight sampling chamber operating at ambient pressure.

  1. Microfabricated triggered vacuum switch

    DOEpatents

    Roesler, Alexander W.; Schare, Joshua M.; Bunch, Kyle

    2010-05-11

    A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

  2. ENHANCED THERMAL VACUUM TEST CAPABILITY FOR RADIOISOTOPE POWER SYSTEMS AT THE IDAHO NATIONAL LABORATORY BETTER SIMULATES ENVIRONMENTAL CONDITIONS OF SPACE

    SciTech Connect

    J. C. Giglio; A. A. Jackson

    2012-03-01

    The Idaho National Laboratory (INL) is preparing to fuel and test the Advanced Stirling Radioisotope Generator (ASRG), the next generation space power generator. The INL identified the thermal vacuum test chamber used to test past generators as inadequate. A second vacuum chamber was upgraded with a thermal shroud to process the unique needs and to test the full power capability of the new generator. The thermal vacuum test chamber is the first of its kind capable of testing a fueled power system to temperature that accurately simulate space. This paper outlines the new test and set up capabilities at the INL.

  3. Ultrasonic Drying Processing Chamber

    NASA Astrophysics Data System (ADS)

    Acosta, V.; Bon, J.; Riera, E.; Pinto, A.

    The design of a high intensity ultrasonic chamber for drying process was investigated. The acoustic pressure distribution in the ultrasonic drying chamber was simulated solving linear elastic models with attenuation for the acoustic-structure interaction. Together with the government equations, the selection of appropriate boundary conditions, mesh refinement, and configuration parameters of the calculation methods, which is of great importance to simulate adequately the process, were considered. Numerical solution, applying the finite element method (FEM), of acoustic-structure interactions involves to couple structural and fluid elements (with different degrees of freedom), whose solution implies several problems of hardware requirements and software configuration, which were solved. To design the drying chamber, the influence of the directivity of the drying open camera and the staggered reflectors over the acoustic pressure distribution was analyzed. Furthermore, to optimize the influence of the acoustic energy on the drying process, the average value of the acoustic energy distribution in the drying chamber was studied. This would determine the adequate position of the food samples to be dried. For this purpose, the acoustic power absorbed by the samples will be analyzed in later studies.

  4. Improved wire chamber

    DOEpatents

    Atac, M.

    1987-05-12

    An improved gas mixture for use with proportional counter devices, such as Geiger-Mueller tubes and drift chambers. The improved gas mixture provides a stable drift velocity while eliminating wire aging caused by prior art gas mixtures. The new gas mixture is comprised of equal parts argon and ethane gas and having approximately 0.25% isopropyl alcohol vapor. 2 figs.

  5. Liquid Wall Chambers

    SciTech Connect

    Meier, W R

    2011-02-24

    The key feature of liquid wall chambers is the use of a renewable liquid layer to protect chamber structures from target emissions. Two primary options have been proposed and studied: wetted wall chambers and thick liquid wall (TLW) chambers. With wetted wall designs, a thin layer of liquid shields the structural first wall from short ranged target emissions (x-rays, ions and debris) but not neutrons. Various schemes have been proposed to establish and renew the liquid layer between shots including flow-guiding porous fabrics (e.g., Osiris, HIBALL), porous rigid structures (Prometheus) and thin film flows (KOYO). The thin liquid layer can be the tritium breeding material (e.g., flibe, PbLi, or Li) or another liquid metal such as Pb. TLWs use liquid jets injected by stationary or oscillating nozzles to form a neutronically thick layer (typically with an effective thickness of {approx}50 cm) of liquid between the target and first structural wall. In addition to absorbing short ranged emissions, the thick liquid layer degrades the neutron flux and energy reaching the first wall, typically by {approx}10 x x, so that steel walls can survive for the life of the plant ({approx}30-60 yrs). The thick liquid serves as the primary coolant and tritium breeding material (most recent designs use flibe, but the earliest concepts used Li). In essence, the TLW places the fusion blanket inside the first wall instead of behind the first wall.

  6. Thermal vacuum integrated system test at B-2

    NASA Astrophysics Data System (ADS)

    Kudlac, M. T.; Weaver, H. F.; Cmar, M. D.

    2012-04-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA's third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3 × 10-4 Pa (1 × 10-6 torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (139°R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/m2 at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber's cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  7. Thermal Vacuum Integrated System Test at B-2

    NASA Technical Reports Server (NTRS)

    Kudlac, Maureen T.; Weaver, Harold F.; Cmar, Mark D.

    2012-01-01

    The National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) Plum Brook Station (PBS) Space Propulsion Research Facility, commonly referred to as B-2, is NASA s third largest thermal vacuum facility. It is the largest designed to store and transfer large quantities of liquid hydrogen and liquid oxygen, and is perfectly suited to support developmental testing of chemical propulsion systems as well as fully integrated stages. The facility is also capable of providing thermal-vacuum simulation services to support testing of large lightweight structures, Cryogenic Fluid Management (CFM) systems, electric propulsion test programs, and other In-Space propulsion programs. A recently completed integrated system test demonstrated the refurbished thermal vacuum capabilities of the facility. The test used the modernized data acquisition and control system to monitor the facility during pump down of the vacuum chamber, operation of the liquid nitrogen heat sink (or cold wall) and the infrared lamp array. A vacuum level of 1.3x10(exp -4)Pa (1x10(exp -6)torr) was achieved. The heat sink provided a uniform temperature environment of approximately 77 K (140deg R) along the entire inner surface of the vacuum chamber. The recently rebuilt and modernized infrared lamp array produced a nominal heat flux of 1.4 kW/sq m at a chamber diameter of 6.7 m (22 ft) and along 11 m (36 ft) of the chamber s cylindrical vertical interior. With the lamp array and heat sink operating simultaneously, the thermal systems produced a heat flux pattern simulating radiation to space on one surface and solar exposure on the other surface. The data acquired matched pretest predictions and demonstrated system functionality.

  8. Transfer Chamber for DBD Surface Treatment and Analysis

    NASA Astrophysics Data System (ADS)

    Faust, Jessica; Gershman, Sophia; Daniels, Ryan

    2012-10-01

    Materials that are hydrophobic, smooth, and have low surface tension lead to poor adhesion for printing and coating. Surface modification using atmospheric pressure dielectric barrier discharge (DBD) improves adhesion by activating the surface, increasing its roughness and functionalizing. We have constructed and tested a DBD discharge system that uses a 15kV, 800-1350Hz pulsed dc source and a mixture of gasses at 300-600Torr. Treated surfaces are studied using X-ray photoelectron spectroscopy, Auger electron spectroscopy, and other methods that require high vacuum environment. We designed a portable transfer chamber to move the sample from the atmospheric pressure treatment chamber to a high vacuum surface analysis chamber with minimal interaction with the environment. The transfer chamber was designed to meet the specific requirements of each system; a bellows drive and sample holder to manually move the sample into the transfer chamber; the ability to fill with pure nitrogen gas to prevent contamination of the sample surface; constructed to withstand a range of pressures from 300 to 10-8Torr; the ability to connect compatibly with each system. Proper surface characterization of the sample is crucial to designing an effective treatment system.

  9. Three stage vacuum system for ultralow temperature installation

    NASA Astrophysics Data System (ADS)

    Das, N. K.; Pradhan, J.; Naser, Md Z. A.; Mandal, B. Ch; Roy, A.; Kumar, P.; Mallik, C.; Bhandari, R. K.

    2012-11-01

    We use a three stage vacuum system for developing a dilution fridge at VECC, Kolkata. We aim at achieving a cooling power of 20μW at 100mK for various experiments especially in the field of condensed matter and nuclear physics. The system is essentially composed of four segments-bath cryostat, vacuum system, dilution insert and 3He circulation circuit. Requirement of vacuum system at different stages are different. The vacuum system for cryostat and for internal vacuum chamber located within the helium bath is a common turbo molecular pump backed by scroll pump as to maintain a vacuum ~10-6mbar. For bringing down the temperature of the helium evaporator, we use a high throughput Roots pump backed by a dry pump. The pumping system for 3He distillation chamber (still) requires a high pumping speed, so a turbo drag pump backed by a scroll pump has been installed. As the fridge use precious 3He gas for operation, the entire system has been made to be absolutely leak proof with respect to the 3He gas.

  10. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, Edward H.; Tuckerman, David B.

    1991-01-01

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required.

  11. Mask blank particle inspection in vacuum environments

    NASA Astrophysics Data System (ADS)

    Sekine, Akihiko; Nagahama, Hiroyuki; Tojo, Toru; Akeno, Kiminobu; Hirano, Ryoichi

    2002-10-01

    The mask blank surface inspection system for the electron beam mask writing system (EB mask writer) has developed. This system, that has the small vacuum chamber attachable to EB mask writer, inspects a mask blank that is just before EB writing in vacuum environments. It can inspect whole area of the 230mm mask at 0.3micrometer sensitivity. It also can perform fast inspection by applying the original scanning algorithm for the laser beam. It has the wide detective range from 0.3 to 2.0 micrometers of particle size. It can distinguish sizes of particles in that range. The auto focus function is most important factor for maintaining the sensitivity.

  12. MMS Observatory Thermal Vacuum Results Contamination Summary

    NASA Technical Reports Server (NTRS)

    Rosecrans, Glenn P.; Errigo, Therese; Brieda, Lubos

    2014-01-01

    The MMS mission is a constellation of 4 observatories designed to investigate the fundamental plasma physics of reconnection in the Earths magnetosphere. Each spacecraft has undergone extensive environmental testing to prepare it for its minimum 2 year mission. The various instrument suites measure electric and magnetic fields, energetic particles, and plasma composition. Thermal vacuum testing was conducted at the Naval Research Laboratory (NRL) in their Big Blue vacuum chamber. The individual spacecraft were tested and enclosed in a cryopanel enclosure called a Hamster cage. Specific contamination control validations were actively monitored by several QCMs, a facility RGA, and at times, with 16 Ion Gauges. Each spacecraft underwent a bakeout phase, followed by 4 thermal cycles. Unique aspects of the TV environment included slow pump downs with represses, thruster firings, Helium identification, and monitoring pressure spikes with Ion gauges. Various data from these TV tests will be shown along with lessons learned.

  13. Vacuum die attach for integrated circuits

    DOEpatents

    Schmitt, E.H.; Tuckerman, D.B.

    1991-09-10

    A thin film eutectic bond for attaching an integrated circuit die to a circuit substrate is formed by coating at least one bonding surface on the die and substrate with an alloying metal, assembling the die and substrate under compression loading, and heating the assembly to an alloying temperature in a vacuum. A very thin bond, 10 microns or less, which is substantially void free, is produced. These bonds have high reliability, good heat and electrical conduction, and high temperature tolerance. The bonds are formed in a vacuum chamber, using a positioning and loading fixture to compression load the die, and an IR lamp or other heat source. For bonding a silicon die to a silicon substrate, a gold silicon alloy bond is used. Multiple dies can be bonded simultaneously. No scrubbing is required. 1 figure.

  14. Ultra-high vacuum compatible image furnace

    NASA Astrophysics Data System (ADS)

    Neubauer, A.; BÅ`uf, J.; Bauer, A.; Russ, B.; Löhneysen, H. v.; Pfleiderer, C.

    2011-01-01

    We report the design of an optical floating-zone furnace for single-crystal growth under ultra-high vacuum (UHV) compatible conditions. The system is based on a commercial image furnace, which has been refurbished to be all-metal sealed. Major changes concern the use of UHV rotary feedthroughs and bespoke quartz-metal seals with metal-O-rings at the lamp stage. As a consequence, the procedure of assembling the furnace for crystal growth is changed completely. Bespoke heating jackets permit to bake the system. For compounds with elevated vapor pressures, the ultra-high vacuum serves as a precondition for the use of a high-purity argon atmosphere up to 10 bar. In the ferromagnetic Heusler compound Cu _2MnAl, the improvements of purity result in an improved stability of the molten zone, grain selection, and, hence, single-crystal growth. Similar improvements are observed in traveling-solvent floating-zone growth of the antiferromagnetic Heusler compound Mn _3Si. These improvements underscore the great potential of optical float-zoning for the growth of high-purity single crystals of intermetallic compounds.

  15. Fuel subassembly leak test chamber for a nuclear reactor

    DOEpatents

    Divona, Charles J.

    1978-04-04

    A container with a valve at one end is inserted into a nuclear reactor coolant pool. Once in the pool, the valve is opened by a mechanical linkage. An individual fuel subassembly is lifted into the container by a gripper; the valve is then closed providing an isolated chamber for the subassembly. A vacuum is drawn on the chamber to encourage gaseous fission product leakage through any defects in the cladding of the fuel rods comprising the subassembly; this leakage may be detected by instrumentation, and the need for replacement of the assembly ascertained.

  16. Vacuum deposition system

    SciTech Connect

    Austin, S.; Bark, D.

    1990-05-31

    The Physics Section vacuum deposition system is available for several types of thin film techniques. This vacuum evaporation system operates in the high vacuum range. The evaporation source is a resistive heating element, either a boat or a filament design. Coating is then line of sight from the source. Substrates to be coated can have a maximum diameter of 17 inches. At this time the variations in the thickness of the coatings can be controlled, by monitor, to within about 100 angstroms. The system diagrams follow the Operation Procedures and the Sample Coating Procedures provided in this document. 3 figs.

  17. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2000-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  18. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John

    2001-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  19. Ultra-high vacuum photoelectron linear accelerator

    DOEpatents

    Yu, David U.L.; Luo, Yan

    2013-07-16

    An rf linear accelerator for producing an electron beam. The outer wall of the rf cavity of said linear accelerator being perforated to allow gas inside said rf cavity to flow to a pressure chamber surrounding said rf cavity and having means of ultra high vacuum pumping of the cathode of said rf linear accelerator. Said rf linear accelerator is used to accelerate polarized or unpolarized electrons produced by a photocathode, or to accelerate thermally heated electrons produced by a thermionic cathode, or to accelerate rf heated field emission electrons produced by a field emission cathode.

  20. Enhanced vacuum arc vapor deposition electrode

    NASA Technical Reports Server (NTRS)

    Weeks, Jack L. (Inventor); Todd, Douglas M. (Inventor)

    1999-01-01

    A process for forming a thin metal coating on a substrate wherein a gas stream heated by an electrical current impinges on a metallic target in a vacuum chamber to form a molten pool of the metal and then vaporize a portion of the pool, with the source of the heated gas stream being on one side of the target and the substrate being on the other side of the target such that most of the metallic vapor from the target is directed at the substrate.

  1. Combustor with fuel preparation chambers

    NASA Technical Reports Server (NTRS)

    Zelina, Joseph (Inventor); Myers, Geoffrey D. (Inventor); Srinivasan, Ram (Inventor); Reynolds, Robert S. (Inventor)

    2001-01-01

    An annular combustor having fuel preparation chambers mounted in the dome of the combustor. The fuel preparation chamber comprises an annular wall extending axially from an inlet to an exit that defines a mixing chamber. Mounted to the inlet are an air swirler and a fuel atomizer. The air swirler provides swirled air to the mixing chamber while the atomizer provides a fuel spray. On the downstream side of the exit, the fuel preparation chamber has an inwardly extending conical wall that compresses the swirling mixture of fuel and air exiting the mixing chamber.

  2. 50. BOILER CHAMBER No. 1, LOOKING SOUTHEAST BETWEEN CHAMBER AND ...

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

    50. BOILER CHAMBER No. 1, LOOKING SOUTHEAST BETWEEN CHAMBER AND ENCLOSURE (LOCATION III) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  3. 61. BOILER CHAMBER No. 2, LOOKING SOUTHWEST BETWEEN CHAMBER AND ...

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

    61. BOILER CHAMBER No. 2, LOOKING SOUTHWEST BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION PPP) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  4. 44. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION CCC), ...

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

    44. AUXILIARY CHAMBER BETWEEN CHAMBER AND CONCRETE ENCLOSURE (LOCATION CCC), LOOKING NORTHEAST SHOWING DRAIN PIPE FROM SUMP - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  5. 41. AUXILIARY CHAMBER, CONCRETE ENCLOSURE CHAMBER AIR LOCK (EXTERIOR), LOOKING ...

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

    41. AUXILIARY CHAMBER, CONCRETE ENCLOSURE CHAMBER AIR LOCK (EXTERIOR), LOOKING NORTHEAST FROM SOUTHWEST CORNER (LOCATION AAA) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  6. 72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR ...

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

    72. VISITOR'S CENTER, MODEL OF BOILER CHAMBER, AUXILIARY CHAMBER, REACTOR AND CANAL (LOCATION T) - Shippingport Atomic Power Station, On Ohio River, 25 miles Northwest of Pittsburgh, Shippingport, Beaver County, PA

  7. Collapse of vacuum bubbles in a vacuum

    SciTech Connect

    Ng, Kin-Wang; Wang, Shang-Yung

    2011-02-15

    We revisit the dynamics of a false vacuum bubble in a background de Sitter spacetime. We find that there exists a large parameter space that allows the bubble to collapse into a black hole or to form a wormhole. This may have interesting implications for the creation of a baby universe in the laboratory, the string landscape where the bubble nucleation takes place among a plenitude of metastable vacua, and the inflationary physics.

  8. Three chamber negative ion source

    DOEpatents

    Leung, Ka-Ngo; Ehlers, Kenneth W.; Hiskes, John R.

    1985-01-01

    A negative ion vessel is divided into an excitation chamber, a negative ionization chamber and an extraction chamber by two magnetic filters. Input means introduces neutral molecules into a first chamber where a first electron discharge means vibrationally excites the molecules which migrate to a second chamber. In the second chamber a second electron discharge means ionizes the molecules, producing negative ions which are extracted into or by a third chamber. A first magnetic filter prevents high energy electrons from entering the negative ionization chamber from the excitation chamber. A second magnetic filter prevents high energy electrons from entering the extraction chamber from the negative ionizing chamber. An extraction grid at the end of the negative ion vessel attracts negative ions into the third chamber and accelerates them. Another grid, located adjacent to the extraction grid, carries a small positive voltage in order to inhibit positive ions from migrating into the extraction chamber and contour the plasma potential. Additional electrons can be suppressed from the output flux using ExB forces provided by magnetic field means and the extractor grid electric potential.

  9. Vacuum Camera Cooler

    NASA Technical Reports Server (NTRS)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  10. Multiwire proportional chamber development

    NASA Technical Reports Server (NTRS)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  11. CONTINUOUSLY SENSITIVE BUBBLE CHAMBER

    DOEpatents

    Good, R.H.

    1959-08-18

    A radiation detector of the bubble chamber class is described which is continuously sensitive and which does not require the complex pressure cycling equipment characteristic of prior forms of the chamber. The radiation sensitive element is a gas-saturated liquid and means are provided for establishing a thermal gradient across a region of the liquid. The gradient has a temperature range including both the saturation temperature of the liquid and more elevated temperatures. Thus a supersaturated zone is created in which ionizing radiations may give rise to visible gas bubbles indicative of the passage of the radiation through the liquid. Additional means are provided for replenishing the supply of gas-saturated liquid to maintaincontinuous sensitivity.

  12. TFTR diagnostic vacuum controller

    SciTech Connect

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller.

  13. The emulsion chamber technology experiment

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1992-01-01

    Photographic emulsion has the unique property of recording tracks of ionizing particles with a spatial precision of 1 micron, while also being capable of deployment over detector areas of square meters or 10's of square meters. Detectors are passive, their cost to fly in Space is a fraction of that of instruments of similar collecting. A major problem in their continued use has been the labor intensiveness of data retrieval by traditional microscope methods. Two factors changing the acceptability of emulsion technology in space are the astronomical costs of flying large electronic instruments such as ionization calorimeters in Space, and the power and low cost of computers, a small revolution in the laboratory microscope data-taking. Our group at UAH made measurements of the high energy composition and spectra of cosmic rays. The Marshall group has also specialized in space radiation dosimetry. Ionization calorimeters, using alternating layers of lead and photographic emulsion, to measure particle energies up to 10(exp 15) eV were developed. Ten balloon flights were performed with them. No such calorimeters have ever flown in orbit. In the ECT program, a small emulsion chamber was developed and will be flown on the Shuttle mission OAST-2 to resolve the principal technological questions concerning space exposures. These include assessments of: (1) pre-flight and orbital exposure to background radiation, including both self-shielding and secondary particle generation; the practical limit to exposure time in space can then be determined; (2) dynamics of stack to optimize design for launch and weightlessness; and (3) thermal and vacuum constraints on emulsion performance. All these effects are cumulative and affect our ability to perform scientific measurements but cannot be adequately predicted by available methods.

  14. Advanced thrust chamber designs

    NASA Technical Reports Server (NTRS)

    Dietrich, F. J.; Leach, A. E.

    1971-01-01

    A regeneratively cooled thrust chamber has been designed and fabricated, consisting of an inner TD nickel liner which was spin formed, welded, and machined and an outer shell of electroformed nickel. Coolant channels were produced in the outer surface of the inner liner by the electric discharge machining process before electroforming the shell. Accessory manifolds and piping were attached by welding. Manufacturing processes employed are described.

  15. Digital optical spark chambers

    NASA Technical Reports Server (NTRS)

    Evenson, Paul; Tuska, Evelyn

    1989-01-01

    The authors constructed and tested a prototype digital readout system for optical spark chambers using a linear, solid-state charge-coupled-device detector array. Position resolution of 0.013 mm (sigma) over a 25-cm field of view has been demonstrated. It is concluded that this technique should permit the construction of economical, lightweight and low-power trajectory hodoscopes for use in cosmic-ray instrumentation on balloons and in spacecraft.

  16. Vacuum system operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1994-03-01

    This report presents a review of vacuum system operating experiences from particle accelerator, fusion experiment, space simulation chamber, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of vacuum system component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with vacuum systems are discussed, including personnel safety, foreign material intrusion, and factors relevant to vacuum systems being the primary confinement boundary for tritium and activated dusts. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor.

  17. Vacuum breaker valve assembly

    DOEpatents

    Thompson, J.L.; Upton, H.A.

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

  18. Vacuum breaker valve assembly

    DOEpatents

    Thompson, Jeffrey L.; Upton, Hubert Allen

    1999-04-27

    Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

  19. Mass Spectrometry of 3D-printed Materials in Vacuum

    NASA Astrophysics Data System (ADS)

    Rivera, W. F.; Romero-Talamás, C. A.; Bates, E. M.; Birmingham, W.

    2014-10-01

    We present the design and preliminary results of a mass spectrometry system to assess vacuum compatibility of 3D-printed parts. The setup consists of a vacuum chamber with a residual gas analyzer (RGA), a radiation heater, and windows for optical measurements of samples. The signal from the RGA is analyzed by creating a system of equations from the calibration signal from a large number of molecular spectra (the so-called cracking patterns). The equations are then inverted to find the most likely true elements in the chamber. The setup can be used as a stand-alone system, or attached to another vacuum chamber at higher pressure using differential pumping. The latter mode will be used in the Dusty Plasma Experiment at UMBC, since many of the plasma facing parts are 3D-printed. Mass spectra of electroplated plastic parts, which have a much better vacuum compatibility than non-plated plastic parts, is also obtained and compared to those without electroplating.

  20. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, R.D.

    1999-03-16

    A vertical two chamber reaction furnace is disclosed. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700 and 800 C) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800 to 950 C to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product. 2 figs.

  1. Vertical two chamber reaction furnace

    DOEpatents

    Blaugher, Richard D.

    1999-03-16

    A vertical two chamber reaction furnace. The furnace comprises a lower chamber having an independently operable first heating means for heating the lower chamber and a gas inlet means for admitting a gas to create an ambient atmosphere, and an upper chamber disposed above the lower chamber and having an independently operable second heating means for heating the upper chamber. Disposed between the lower chamber and the upper chamber is a vapor permeable diffusion partition. The upper chamber has a conveyor means for conveying a reactant there through. Of particular importance is the thallinating of long-length thallium-barium-calcium-copper oxide (TBCCO) or barium-calcium-copper oxide (BCCO) precursor tapes or wires conveyed through the upper chamber to thereby effectuate the deposition of vaporized thallium (being so vaporized as the first reactant in the lower chamber at a temperature between about 700.degree. and 800.degree. C.) on TBCCO or BCCO tape or wire (the second reactant) at its simultaneous annealing temperature in the upper chamber of about 800.degree. to 950.degree. C. to thereby replace thallium oxide lost from TBCCO tape or wire because of the high annealing temperature or to deposit thallium on BCCO tape or wire. Continuously moving the tape or wire provides a single-step process that effectuates production of long-length TBCCO superconducting product.

  2. Vacuum system for the LBL advanced light source (ALS)

    SciTech Connect

    Kennedy, K.

    1988-05-01

    A 1.5 to 1.9 GeV synchrotron light source is being built at LBL. The vacuum system is designed to permit all synchrotron photons on the median plane to escape the electron channel and go into an antechamber through a 10 mm high slot. This slot offers effective RF isolation between the electron duct and the antechamber. All unused synchrotron photons within a few mrad of the median plane will be stopped by 96 nearly horizontal absorbers located in the antechamber. The gas, generated by the photons hitting the absorbers, will be directed down to reactive titanium surfaces. Twelve 10 meter long vessels constitute the vacuum chambers for all the lattice magnets. Each chamber will be machined from two thick plates of 5083-H321 aluminum and welded at the perimeter. The nominal wall thickness of the vacuum chamber is 40 mm, which makes it possible to machine a flange into the chamber without the use of welding. 5 refs., 5 figs.

  3. Directional molecular flow analysis and leak detection with a rotatable gas analyzer in a large space simulation chamber

    NASA Technical Reports Server (NTRS)

    Ehlers, H. K. F.

    1972-01-01

    A system was developed and applied at the NASA Manned Spacecraft Center for measuring and analyzing directional molecular flows in a large thermal vacuum chamber in order to verify molecular environment and identify characteristic and abnormal test article and chamber conditions. The system is described, and some results obtained in over 1200 hours of operation are given.

  4. A space simulation chamber for space power insulation

    NASA Astrophysics Data System (ADS)

    Banford, H. M.; Given, M. J.; Tedford, D. J.

    1995-01-01

    An account is given of an experimental facility which has been designed specifically for the study of electrical insulation in a simulated space environment. Insulation in space can experience a very wide range of environmental stimuli and it is very difficult if not impossible to stimulate them all. Those that are considered in the present work are vacuum, temperature, nuclear radiation and atomic oxygen. The facility consists of a stainless steel high-vacuum chamber with a sample mounting arrangement which allows sample temperatures to be varied between 80 and 470 K. Test specimens can also be exposed to electromagnetic radiation within the chamber. Atomic oxygen treatment of materials takes place before they are introduced to the chamber. The materials being considered are Kapton and an epoxy resin formulation. Various electrical measurements are being undertaken and comprise primarily dielectric loss by frequency domain spectroscopy and pre-breakdown current pulse activity under direct stress, while the provision exists for conductivity and breakdown measurements as well. These are made in real time under vacuum, temperature and low dose rate electromagnetic radiation following an ageing procedure which involves combinations of these three foregoing environmental stimuli and atomic oxygen.

  5. Multi-anode ionization chamber

    DOEpatents

    Bolotnikov, Aleksey E.; Smith, Graham; Mahler, George J.; Vanier, Peter E.

    2010-12-28

    The present invention includes a high-energy detector having a cathode chamber, a support member, and anode segments. The cathode chamber extends along a longitudinal axis. The support member is fixed within the cathode chamber and extends from the first end of the cathode chamber to the second end of the cathode chamber. The anode segments are supported by the support member and are spaced along the longitudinal surface of the support member. The anode segments are configured to generate at least a first electrical signal in response to electrons impinging thereon.

  6. APPARATUS FOR VACUUM DEPOSITION OF METALS

    DOEpatents

    Milleron, N.

    1962-03-13

    An apparatus and a method are described for continuous vacuum deposition of metals for metallic coatings, for ultra-high vacuum work, for purification of metals, for maintaining high-density electron currents, and for other uses. The apparatus comprises an externally cooled feeder tube extending into a container and adapted to feed metal wire or strip so that it emerges in a generally vertical position therein. The tube also provides shielding from the heat produced by an electron beam therein focused to impinge from a vertical direction upon the tip of the emerging wire. By proper control of the wire feed, coolant feed, and electron beam intensity, a molten ball of metal forms upon the emerging tip and remains self-supported thereon by the interaction of various forces. The metal is vaporized and travels in a line of sight direction, while additional wire is fed from the tube, so that the size of the molten ball remains constant. In the preferred embodiments, the wire is selected from a number of gettering metals and is degassed by electrical resistance in an adjacent chamber which is also partially evacuated. The wire is then fed through the feed tube into the electron beam and vaporizes and adsorbs gases to provide pumping action while being continuously deposited upon surfaces within the chamber. Ion pump electrodes may also be provided within line of sight of the vaporizing metal source to enhance the pumping action. (AEC)

  7. ISABELLE vacuum systems

    SciTech Connect

    Halama, H J

    1980-01-01

    The Intersecting Storage Accelerator (ISABELLE) consists of two rings having a circumference of 3.8 km each. In these rings superconducting magnets, held at 4 K, bend and focus the proton beam which is accelerated up to 400 GeV. Due to very different pressure requirements, ISABELLE has two completely independent vacuum systems. One, which operates at 1 x 10/sup -11/ Torr, provides a very clean environment for the circulating proton beam. Here only ion and titanium sublimation pumps are used to provide the vacuum. The other system maintains superconducting magnet vessels at a pressure below 1 x 10/sup -4/ Torr, since at this pressure the gas conduction becomes negligible. In this so-called insulating vacuum system, turbomolecular pumps pump the inadvertent small helium leaks. Other gases are cryocondensed on the cold surfaces of the cryogenic system. The basic element of ISABELLE known as Full Cell containing 45 meters of beam tube, 8 pumping stations, 8 superconducting magnets and complete instrumentation has been constructed, leak checked and tested. All design parameters have been achieved in both vacuum systems. The two vacuum systems are described with particular emphasis on the influence of superconducting magnets in the selection of materials and UHV components.

  8. Wire chambers revisited.

    PubMed

    Ott, R J

    1993-04-01

    Detectors used for radioisotope imaging have, historically, been based on scintillating crystal/photomultiplier combinations in various forms. From the rectilinear scanner through to modern gamma cameras and positron cameras, the basic technology has remained much the same. Efforts to overcome the limitations of this form of technology have foundered on the inability to reproduce the required sensitivity, spatial resolution and sensitive area at acceptable cost. Multiwire proportional chambers (MWPCs) have long been used as position-sensitive charged particle detectors in nuclear and high-energy physics. MWPCs are large-area gas-filled ionisation chambers in which large arrays of fine wires are used to measure the position of ionisation produced in the gas by the passage of charged particles. The important properties of MWPCs are high-spatial-resolution, large-area, high-count-rate performance at low cost. For research applications, detectors several metres square have been built and small-area detectors have a charged particle resolution of 0.4 mm at a count rate of several million per second. Modification is required to MWPCs for nuclear medicine imaging. As gamma rays or X-rays cannot be detected directly, they must be converted into photo- or Compton scatter electrons. Photon-electron conversion requires the use of high atomic number materials in the body of the chamber. Pressurised xenon is the most useful form of "gas only" photon-electron convertor and has been used successfully in a gamma camera for the detection of gamma rays at energies below 100 keV. This camera has been developed specifically for high-count-rate first-pass cardiac imaging. This high-pressure xenon gas MWPC is the key to a highly competitive system which can outperform scintillator-based systems. The count rate performance is close to a million counts per second and the intrinsic spatial resolution is better than the best scintillator-based camera. The MWPC camera produces quantitative

  9. Review of wire chamber aging

    SciTech Connect

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs.

  10. Dedicated contamination experiments in the Orion laser target chamber

    NASA Astrophysics Data System (ADS)

    Andrew, J.; Chevalier, J.-M.; Egan, D.; Geille, A.; Jadaud, J.-P.; Quessada, J.-H.; Raffestin, D.; Rubery, M.; Treadwell, P.; Videau, L.

    2015-11-01

    The use of solid targets irradiated in a vacuum target chamber by focussed high energy, high power laser beams to study the properties of matter at high densities, pressures and temperatures are well known. An undesirable side effect of these interactions is the generation of plumes of solid, liquid and gaseous matter which move away from the target and coat or physically damage surfaces within the target chamber. The largest aperture surfaces in these chambers are usually the large, high specification optical components used to produce the extreme conditions being studied [e.g. large aperture off axis parabolas, aspheric lenses, X ray optics and planar debris shields]. In order to study these plumes and the effects that they produce a set of dedicated experiments were performed to evaluate target by product coating distributions and particle velocities by a combined diagnostic instrument that utilised metal witness plates, polymer witness plates, fibre velocimetry and low density foam particle catchers.

  11. Numerical grid generation and flow simulation in SSME thrust chamber

    SciTech Connect

    Gross, K.W.; Daley, P.L.; Przekwas, A.J.

    1987-01-01

    The development of liquid and solid rocket engines for future space projects demands a detailed optimization process for highly efficient performance and cost reasons. Also, testing of full size engines may not be feasible when the large size requires test facilities which are cost prohibitive or if vacuum operation cannot be acquired. For such situations only scaling from small test scale measurements or accurate analytical predictions will provide the performance prior to actually flying the mission. A rigorous approach for simulating the combustion processes in liquid rocket engines by employing a direct solution of Navier-Stokes equations within the entire volume of the thrust chambers is presented. This method is illustrated in the solution of reactive flow in the Space Shuttle Main Engine (SSME) thrust chamber. The objective is to review recent improvements in the mathematical model and to present the grid generation methodology suitable for rocket thrust chamber geometries.

  12. The coated cathode conductive layer chamber

    NASA Astrophysics Data System (ADS)

    Bouclier, R.; Gaudaen, J.; Sauli, F.

    1991-12-01

    We describe a gaseous detector consisting of thin anode strips vacuum-evaporated on one side of a 100 μm thick plastic layer, alternating on the back side of the same foil with wider parallel cathode strips. Ionization released in a drift space on the anode side is amplified and detected much in the same way as in the microstrip gas chamber; in our detector however spontaneous breakdown due to surface currents is completely avoided by the presence of the insulating layer between anodes and cathodes. To reduce surface and volume charging up, we have used polymer foils with a moderate volume resistivity. The first results show good efficiency, good plateaux and time resolution in detecting low-rate minimum ionizing electrons. Although not suited for high rate or good energy resolution applications, this kind of detector seems rather promising for realizing cheaply large active surfaces.

  13. Preparation of Morpheus Vehicle for Vacuum Environment Testing

    NASA Technical Reports Server (NTRS)

    Sandoval, Armando

    2016-01-01

    The main objective for this summer 2016 tour was to prepare the Morpheus vehicle for its upcoming test inside Plum Brook's vacuum chamber at NASA John H. Glenn Research Center. My contributions towards this project were mostly analytical in nature, providing numerical models to validate test data, generating computer aided analyses for the structure support of the vehicle's engine, and designing a vacuum can that is to protect the high speed camera used during testing. Furthermore, I was also tasked with designing a tank toroidal spray bar system.

  14. Communication: vacuum ultraviolet photoabsorption of interstellar icy thiols.

    PubMed

    Bhuin, Radha Gobinda; Sivaraman, Bhalamurugan; Lo, Jen-Iu; Sekhar, B N Raja; Cheng, Bing-Ming; Pradeep, Thalappil; Mason, Nigel John

    2014-12-21

    Following the recent identification of ethanethiol in the interstellar medium (ISM) we have carried out Vacuum UltraViolet (VUV) spectroscopy studies of ethanethiol (CH3CH2SH) from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. These results are compared with those of methanethiol (CH3SH), the lower order thiol also reported to be present in the ISM. VUV spectra recorded at higher temperature reveal conformational changes in the ice and phase transitions whilst evidence for dimer production is also presented. PMID:25527912

  15. Communication: Vacuum ultraviolet photoabsorption of interstellar icy thiols

    NASA Astrophysics Data System (ADS)

    Bhuin, Radha Gobinda; Sivaraman, Bhalamurugan; Lo, Jen-Iu; Sekhar, B. N. Raja; Cheng, Bing-Ming; Pradeep, Thalappil; Mason, Nigel John

    2014-12-01

    Following the recent identification of ethanethiol in the interstellar medium (ISM) we have carried out Vacuum UltraViolet (VUV) spectroscopy studies of ethanethiol (CH3CH2SH) from 10 K until sublimation in an ultrahigh vacuum chamber simulating astrochemical conditions. These results are compared with those of methanethiol (CH3SH), the lower order thiol also reported to be present in the ISM. VUV spectra recorded at higher temperature reveal conformational changes in the ice and phase transitions whilst evidence for dimer production is also presented.

  16. Improving Vacuum Cleaners

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  17. Characterization of the CEBAF 100 kV DC GaAs Photoelectron Gun Vacuum System

    SciTech Connect

    Stutzman, M L; Adderley, P; Brittian, J; Clark, J; Grames, J; Hansknecht, J; Myneni, G R; Poelker, M

    2007-05-01

    A vacuum system with pressure in the low ultra-high vacuum (UHV) range is essential for long photocathode lifetimes in DC high voltage GaAs photoguns. A discrepancy between predicted and measured base pressure in the CEBAF photoguns motivated this study of outgassing rates of three 304 stainless steel chambers with different pretreatments and pump speed measurements of non-evaporable getter (NEG) pumps. Outgassing rates were measured using two independent techniques. Lower outgassing rates were achieved by electropolishing and vacuum firing the chamber. The second part of the paper describes NEG pump speed measurements as a function of pressure through the lower part of the UHV range. Measured NEG pump speed is high at pressures above 5×10-11 Torr, but may decrease at lower pressures depending on the interpretation of the data. The final section investigates the pump speed of a locally produced NEG coating applied to the vacuum chamber walls. These studies represent the first detailed vacuum measurements of CEBAF photogun vacuum chambers.

  18. Characterization of the CEBAF 100 kV DC GaAs photoelectron gun vacuum system

    NASA Astrophysics Data System (ADS)

    Stutzman, M. L.; Adderley, P.; Brittian, J.; Clark, J.; Grames, J.; Hansknecht, J.; Myneni, G. R.; Poelker, M.

    2007-05-01

    A vacuum system with pressure in the low ultra-high vacuum (UHV) range is essential for long photocathode lifetimes in DC high voltage GaAs photoguns. A discrepancy between predicted and measured base pressure in the CEBAF photoguns motivated this study of outgassing rates of three 304 stainless steel chambers with different pretreatments and pump speed measurements of non-evaporable getter (NEG) pumps. Outgassing rates were measured using two independent techniques. Lower outgassing rates were achieved by electropolishing and vacuum firing the chamber. The second part of the paper describes NEG pump speed measurements as a function of pressure through the lower part of the UHV range. Measured NEG pump speed is high at pressures above 5×10 -11 Torr, but may decrease at lower pressures depending on the interpretation of the data. The final section investigates the pump speed of a locally produced NEG coating applied to the vacuum chamber walls. These studies represent the first detailed vacuum measurements of CEBAF photogun vacuum chambers.

  19. Absolute photon-flux measurements in the vacuum ultraviolet

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Haddad, G. N.

    1974-01-01

    Absolute photon-flux measurements in the vacuum ultraviolet have extended to short wavelengths by use of rare-gas ionization chambers. The technique involves the measurement of the ion current as a function of the gas pressure in the ion chamber. The true value of the ion current, and hence the absolute photon flux, is obtained by extrapolating the ion current to zero gas pressure. Examples are given at 162 and 266 A. The short-wavelength limit is determined only by the sensitivity of the current-measuring apparatus and by present knowledge of the photoionization processes that occur in the rate gases.

  20. Status of NSLS-II Storage Ring Vacuum Systems

    SciTech Connect

    Doom,L.; Hseuh,H.; Ferreira, M.; Longo, C.; Ravindranath, V.; Settepani, P.; Sharma, S.; Wilson, K.

    2009-05-04

    National Synchrotron Light Source II (NSLS-II), being constructed at Brookhaven National Laboratory, is a 3-GeV, high-flux and high- brightness synchrotron radiation facility with a nominal current of 500 mA. The storage ring vacuum system will have extruded aluminium chambers with ante-chamber for photon fans and distributed NEG strip pumping. Discrete photon absorbers will be used to intercept the un-used bending magnet radiation. In-situ bakeout will be implemented to achieve fast conditioning during initial commissioning and after interventions.

  1. Study of the trapped modes at the vacuum ports

    SciTech Connect

    Heifets, S.; Stupakov, G.

    1995-01-01

    Pumping ports in PEP-II vacuum chamber will be shielded with slots cut in the walls of the beam pipe. The number of slots n{sub s}, their length l, and width w are defined by the required pumping conductance. The present design has 40 slots around the stainless steel round pipe in the straight sections, and, for the rectangular copper chamber of the arcs, there are 18 slots placed in upper and lower decks. Here we want to address two potential problems related to the slots: radiation of the TE HOM-s through the slots, and generation of the trapped modes.

  2. Diffuser-ejector system for a very high vacuum environment

    SciTech Connect

    Riggs, K.E.

    1984-06-19

    A system for testing space engines at sea level under a very low pressure environment. The system includes a space simulation chamber connected to a diffuser, which has two variable area ratio ejectors connected to it in tandem. Each of the ejectors is driven by a jet engine, preferably a turbo jet. The system is capable of providing a low pressure environment of about three or four millimeters of mercury for testing of engines mounted in the space simulation chamber. The system also may be used for other purposes requiring very high vacuum, such as evaporation and dehydration of food products or drugs.

  3. Vacuum MOCVD fabrication of high efficience cells

    NASA Technical Reports Server (NTRS)

    Partain, L. D.; Fraas, L. M.; Mcleod, P. S.; Cape, J. A.

    1985-01-01

    Vacuum metal-organic-chemical-vapor-deposition (MOCVD) is a new fabrication process with improved safety and easier scalability due to its metal rather than glass construction and its uniform multiport gas injection system. It uses source materials more efficiently than other methods because the vacuum molecular flow conditions allow the high sticking coefficient reactants to reach the substrates as undeflected molecular beams and the hot chamber walls cause the low sticking coefficient reactants to bounce off the walls and interact with the substrates many times. This high source utilization reduces the materials costs power device and substantially decreases the amounts of toxic materials that must be handled as process effluents. The molecular beams allow precise growth control. With improved source purifications, vacuum MOCVD has provided p GaAs layers with 10-micron minority carrier diffusion lengths and GaAs and GaAsSb solar cells with 20% AMO efficiencies at 59X and 99X sunlight concentration ratios. Mechanical stacking has been identified as the quickest, most direct and logical path to stacked multiple-junction solar cells that perform better than the best single-junction devices. The mechanical stack is configured for immediate use in solar arrays and allows interconnections that improve the system end-of-life performance in space.

  4. Transfer orbit stage mechanisms thermal vacuum test

    NASA Technical Reports Server (NTRS)

    Oleary, Scott T.

    1990-01-01

    A systems level mechanisms test was conducted on the Orbital Sciences Corp.'s Transfer Orbit Stage (TOS). The TOS is a unique partially reusable transfer vehicle which will boost a satellite into its operational orbit from the Space Shuttle's cargo bay. The mechanical cradle and tilt assemblies will return to earth with the Space Shuttle while the Solid Rocket Motor (SRM) and avionics package are expended. A mechanisms test was performed on the forward cradle and aft tilting assemblies of the TOS under thermal vacuum conditions. Actuating these assemblies under a 1 g environment and thermal vacuum conditions proved to be a complex task. Pneumatic test fixturing was used to lift the forward cradle, and tilt the SRM, and avionics package. Clinometers, linear voltage displacement transducers, and load cells were used in the thermal vacuum chamber to measure the performance and characteristics of the TOS mechanism assembly. Incorporation of the instrumentation and pneumatic system into the test setup was not routine since pneumatic actuation of flight hardware had not been previously performed in the facility. The methods used are presented along with the problems experienced during the design, setup and test phases.

  5. VACUUM SEALING MEANS FOR LOW VACUUM PRESSURES

    DOEpatents

    Milleron, N.

    1962-06-12

    S>A vacuum seal is designed in which the surface tension of a thin layer of liquid metal of low vapor pressure cooperates with adjacent surfaces to preclude passages of gases across pressure differentials as low as 10/sup -8/ mm Hg. Mating contiguous surfaces composed of copper, brass, stainless steel, nickel, molybdenum, tungsten, tantalum, glass, quartz, and/or synthetic mica are disposed to provide a maximum tolerance, D, expressed by 2 gamma /P/sub 1/, where gamma is the coefflcient of the surface tension of the metal sealant selected in dynes/cm/sub 2/. Means for heating the surfaces remotely is provided where temperatures drop below about 250 deg C. A sealant consisting of an alloy of gallium, indium, and tin, among other combinations tabulated, is disposed therebetween after treating the surfaces to improve wettability, as by ultrasonic vibrations, the surfaces and sealants being selected according to the anticipated experimental conditions of use. (AEC)

  6. Short communication: Effect of vacuum and ratio on the performance of a monoblock silicone milking liner.

    PubMed

    Spencer, S B; Shin, J-W; Rogers, G W; Cooper, J B

    2007-04-01

    The vacuum and teat-cup chamber ratio are important operating parameters that affect milking performance by milking machines. In addition, the design and composition of materials are major elements affecting the performance characteristics of (teat-cup) milking machine liners. The objective of this experiment was to determine the effects of vacuum and teat-cup chamber ratio on the performance of a unique mono-block silicone milking machine liner that is round in the open position and triangular in the collapsed position. System vacuum settings (set at receiver) were 40.6, 43.9, and 47.3 kPa, whereas teat-cup chamber ratios were 60:40, 65:35, and 70:30. Milk yield was greatest at a vacuum of 43.9 kPa. Manual adjustments and kickoffs were very low (<2%) at all vacuum levels and for all ratios. The interaction of vacuum level and ratio was significant for milking duration, peak flow rate, and average flow rate, but not for milk yield. Average and peak milk flow rates increased at each increasing vacuum level and each wider ratio, whereas milking duration decreased. PMID:17369212

  7. Langmuir vacuum and superconductivity

    NASA Astrophysics Data System (ADS)

    Veklenko, B. A.

    2012-06-01

    It is shown that, in the "jelly" model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

  8. Langmuir vacuum and superconductivity

    SciTech Connect

    Veklenko, B. A.

    2012-06-15

    It is shown that, in the 'jelly' model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

  9. Vacuum ultraviolet holography

    NASA Technical Reports Server (NTRS)

    Bjorklund, G. C.; Harris, S. E.; Young, J. F.

    1974-01-01

    We report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182-A radiation. The holograms were recorded in polymethyl methacrylate and examined with an electron microscope. A holographic grating with a fringe spacing of 386 A was produced and far-field Fraunhofer holograms of submicron particles were recorded.

  10. Sorption vacuum trap

    NASA Technical Reports Server (NTRS)

    Barrington, A. E.; Caruso, A. J.

    1970-01-01

    Modified sorption trap for use in high vacuum systems contains provisions for online regeneration of sorbent material. Trap is so constructed that it has a number of encapsulated resistance heaters and a valving and pumping device for removing gases from heated sorbing material. Excessive downtime is eliminated with this trap.

  11. Vacuum ultraviolet holography

    NASA Technical Reports Server (NTRS)

    Bjorklund, G. C.; Harris, S. E.; Young, J. F.

    1974-01-01

    The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded.

  12. Various unique vacuum holders

    SciTech Connect

    Gregar, J.S.

    1992-12-01

    Glassblowers use vacuum holding devices to support a flat plate in the glassflowing lathe to seal onto the end of, or inside of, a glass cylinder. Glassblowing blowhose swivels tend to leak; a rotating union from the hydraulics industry is better. Various graphite holder designs are described.

  13. Vacuum Kundt waves

    NASA Astrophysics Data System (ADS)

    McNutt, David; Milson, Robert; Coley, Alan

    2013-03-01

    We discuss the invariant classification of vacuum Kundt waves using the Cartan-Karlhede algorithm and determine the upper bound on the number of iterations of the Karlhede algorithm to classify the vacuum Kundt waves (Collins (1991 Class. Quantum Grav. 8 1859-69), Machado Ramos (1996 Class. Quantum Grav. 13 1589)). By choosing a particular coordinate system we partially construct the canonical coframe used in the classification to study the functional dependence of the invariants arising at each iteration of the algorithm. We provide a new upper bound, q ⩽ 4, and show that this bound is sharp by analyzing the subclass of Kundt waves with invariant count beginning with (0, 1,…) to show that the class with invariant count (0, 1, 3, 4, 4) exists. This class of vacuum Kundt waves is shown to be unique as the only set of metrics requiring the fourth covariant derivatives of the curvature. We conclude with an invariant classification of the vacuum Kundt waves using a suite of invariants.

  14. Tara vacuum system

    SciTech Connect

    Post, R.S.; Brindza, P.; Goodrich, P.; Gaudreau, M.P.

    1985-11-01

    The Tara tandem mirror experiment vacuum system will be discussed including system design, specifications, and performance required for plug thermal barrier operation. A detailed description of the major pumpig systems, reflux control, plasma pumping, measurement and control, fast gas handling and quality control procedures will be presented. Data from the two 5 month periods of operation will be presented.

  15. Diogene pictorial drift chamber

    SciTech Connect

    Gosset, J.

    1984-01-01

    A pictorial drift chamber, called DIOGENE, has been installed at Saturne in order to study central collisions of high energy heavy ions. It has been adapted from the JADE internal detector, with two major differences to be taken into account. First, the center-of-mass of these collisions is not identical to the laboratory reference frame. Second, the energy loss and the momentum ranges of the particles to be detected are different from the ones in JADE. It was also tried to keep the cost as small as possible, hence the choice of minimum size and minimum number of sensitive wires. Moreover the wire planes are shifted from the beam axis: this trick helps very much to quickly reject the bad tracks caused by the ambiguity of measuring drift distances (positive or negative) through times (always positive).

  16. Mush Column Magma Chambers

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  17. Meeting today's requirements for large thermal vacuum test facilities

    NASA Technical Reports Server (NTRS)

    Corinth, R. L.; Rouse, J. A.

    1986-01-01

    The Lockheed Thermal Vacuum Facility at Sunnyvale, California, completed in late 1986, one of the largest multi-program facilities constructed to date is described. The horizontal 12.2 m diameter by 24.4 m long chamber has removable heads at each end and houses a thermal shroud providing a test volume 10.4 m diameter by 24.4 m long. The chamber and thermal shroud are configured to permit the insertion of a 6.1 m wide by 24.4 m long vibration isolated optical bench. The pumpimg system incorporates an internal cryopumping array, turbomolecular pumps and cryopumps to handle multi-program needs and ranges of gas loads. The high vacuum system is capable of achieving clean, dry and empty pressures below 1.3 times 10 to the minus 6 power Pa (10 to the minus 8 power torr.)

  18. An In-Vacuum BR/TDF Measurement Apparatus

    NASA Astrophysics Data System (ADS)

    Gilliam, L. E.; Osiecki, R. A.

    1987-06-01

    An in-vacuum BR/TDF measurement apparatus has just been assembled as part of a larger space environmental effects facility. The sample stage and detector assemblies are mounted within and the requisite optics train and light sources external to a 48-in. diameter vacuum chamber. The chopped and field stopped f/60 incident beam enters the chamber through a window of appropriate material. Argon ion, helium neon, and CO2 lasers, as well as a xenon arc lamp, are used as light sources. Beam size on the sample is about 1-cm diameter with the detectors mounted on a 60-cm arm. The detectors can be rotated from within about 2° of the incident beam to directly facing the incident beam and can measure reflectance of a normally incident beam to about 83° and transmittance from 150° to 180°.

  19. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  20. Vacuum Drying Technique

    NASA Technical Reports Server (NTRS)

    1979-01-01

    At Valley Forge, Pennsylvania, General Electric Company's Space Division has a large environmental chamber for simulating the conditions under which an orbiting spacecraft operates. Normally it is used to test company-built space systems, such as NASA's Landsat and Nimbus satellites. It is also being used in a novel spinoff application-restoring water-damaged books and other paper products and textiles.

  1. Vacuum design for a superconducting mini-collider

    SciTech Connect

    Barletta, W.A. ); Monteiro, S. )

    1991-04-09

    The phi factory (Superconducting Mini-Collider or SMC) proposed for construction at UCLA is a single storage ring with circulating currents of 2 A each of electrons and positrons. The small circumference exacerbates the difficulties of handling the gas load due to photo-desorption from the chamber walls. We analyze the vacuum system for the phi factory to specify design choices. 7 refs., 6 figs., 1 tab.

  2. Tritium handling in vacuum systems

    SciTech Connect

    Gill, J.T.; Coffin, D.O.

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  3. HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF ...

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

    HATCH CONNECTING TEMPERED AIR CHAMBER AND HOT AIR CHAMBER OF PLENUM WITH ATTACHED DRAFT REGULATOR. - Hot Springs National Park, Bathhouse Row, Superior Bathhouse: Mechanical & Piping Systems, State Highway 7, 1 mile north of U.S. Highway 70, Hot Springs, Garland County, AR

  4. A radiation hard vacuum switch

    DOEpatents

    Boettcher, G.E.

    1988-07-19

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction. 3 figs.

  5. Vacuum Compatibility of Flux-Core Arc Welding (FCAW)

    NASA Astrophysics Data System (ADS)

    Arose, Dana; Denault, Martin; Jurcznski, Stephan

    2010-11-01

    Typically, vacuum chambers are welded together using gas tungsten arc welding (GTAW) or gas metal arc welding (GMAW). This is demonstrated in the vacuum chamber of Princeton Plasma Physics Lab's (PPPL) National Spherical Torus Experiment (NSTX). These processes are slow and apply excess heat to the base metal, which may cause the vacuum chamber to deform beyond designed tolerance. Flux cored arc welding (FCAW) avoids these problems, but may produce an unacceptable amount of outgasing due to the flux shielding. We believe impurities due to outgasing from FCAW will not greatly exceed those found in GTAW and GMAW welding. To test this theory, samples welded together using all three welding processes will be made and baked in a residual gas analyzer (RGA). The GTAW and GMAW welds will be tested to establish a metric for permissible outgasing. By testing samples from all three processes we hope to demonstrate that FCAW does not significantly outgas, and is therefore a viable alternative to GTAW and GMAW. Results from observations will be presented.

  6. INTESPACE's new thermal-vacuum test facility: SIMMER

    NASA Technical Reports Server (NTRS)

    Duprat, Raymond; Mouton, Andre

    1992-01-01

    The development of an European satellite market over the last 10 years, the industrialization of space applications, and the new requirements from satellite prime contractors have led INTESPACE to increase the test center's environmental testing capacities through the addition of a new thermal-vacuum test facility of impressive dimensions referred to as the SIMMER. The SIMMER is a simulator specifically created for the purpose of conducting acceptance tests of satellites and of large structures of the double launching ARIANE IV or half ARIANE V classes. The chamber is 8.3 meters long with a diameter of 10 meters. The conceptual design of a chamber in the horizontal plane and at floor level is in a view to simplify test preparation and to permit final electrical checks of the spacecraft in its actual test configuration prior to the closing of the chamber. The characteristics of the SIMMER complies with the requirements being currently defined in terms of thermal-vacuum tests: (1) thermal regulation (temperatures cycling between 100 K and 360 K); (2) clean vacuum (10(exp -6) mbar); (3) 600 measurement channels; and (4) 100 000 cleanliness class. The SIMMER is located in INTESPACE's space vehicle test complex in which a large variety of environmental test facilities are made available for having a whole test program completed under one and a same roof.

  7. Planetary Atmosphere and Surfaces Chamber (PASC): A Platform to Address Various Challenges in Astrobiology

    NASA Astrophysics Data System (ADS)

    Mateo-Marti, Eva

    2014-08-01

    The study of planetary environments of astrobiological interest has become a major challenge. Because of the obvious technical and economical limitations on in situ planetary exploration, laboratory simulations are one of the most feasible research options to make advances both in planetary science and in developing a consistent description of the origin of life. With this objective in mind, we applied vacuum technology to the design of versatile vacuum chambers devoted to the simulation of planetary atmospheres' conditions. These vacuum chambers are able to simulate atmospheres and surface temperatures representative of the majority of planetary objects, and they are especially appropriate for studying the physical, chemical and biological changes induced in a particular sample by in situ irradiation or physical parameters in a controlled environment. Vacuum chambers are a promising potential tool in several scientific and technological fields, such as engineering, chemistry, geology and biology. They also offer the possibility of discriminating between the effects of individual physical parameters and selected combinations thereof. The implementation of our vacuum chambers in combination with analytical techniques was specifically developed to make feasible the in situ physico-chemical characterization of samples. Many wide-ranging applications in astrobiology are detailed herein to provide an understanding of the potential and flexibility of these experimental systems. Instruments and engineering technology for space applications could take advantage of our environment-simulation chambers for sensor calibration. Our systems also provide the opportunity to gain a greater understanding of the chemical reactivity of molecules on surfaces under different environments, thereby leading to a greater understanding of interface processes in prebiotic chemical reactions and facilitating studies of UV photostability and photochemistry on surfaces. Furthermore, the

  8. Surge-damping vacuum valve

    DOEpatents

    Bullock, Jack C.; Kelly, Benjamin E.

    1980-01-01

    A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

  9. Vacuum and magnetic field constraints in a H -/light ion synchrotron

    NASA Astrophysics Data System (ADS)

    Arduini, G.; Martin, R. L.; Rossi, S.; Silari, M.

    1994-08-01

    Acceleration of H - ions in a synchrotron imposes severe restrictions on the level of residual pressure in the vacuum chamber and the maximum magnetic field in the magnets of the ring. Significant vacuum requirements are also imposed by the acceleration of ions. This paper discusses these two aspects of the design of a combined H -/light ion synchrotron for radiation therapy. The fractional loss of the accelerated beam induced by the two processes is evaluated on the basis of a general treatment of the physics of these phenomena. The values of the vacuum and magnetic field necessary for normal operation of the machine are specified and a discussion is given of the behaviour of the above quantities as a function of several parameters such as beam energy, composition and pressure of the residual gas in the vacuum chamber and beam extraction time.

  10. Note: A single-chamber tool for plasma activation and surface functionalization in microfabrication

    PubMed Central

    Bowman, Adam J.; Scherrer, Joseph R.; Reiserer, Ronald S.

    2015-01-01

    We present a simple apparatus for improved surface modification of polydimethylsiloxane (PDMS) microfluidic devices. A single treatment chamber for plasma activation and chemical/physical vapor deposition steps minimizes the time-dependent degradation of surface activation that is inherent in multi-chamber techniques. Contamination and deposition irregularities are also minimized by conducting plasma activation and treatment phases in the same vacuum environment. An inductively coupled plasma driver allows for interchangeable treatment chambers. Atomic force microscopy confirms that silane deposition on PDMS gives much better surface quality than standard deposition methods, which yield a higher local roughness and pronounced irregularities in the surface. PMID:26133881

  11. Note: A single-chamber tool for plasma activation and surface functionalization in microfabrication

    NASA Astrophysics Data System (ADS)

    Bowman, Adam J.; Scherrer, Joseph R.; Reiserer, Ronald S.

    2015-06-01

    We present a simple apparatus for improved surface modification of polydimethylsiloxane (PDMS) microfluidic devices. A single treatment chamber for plasma activation and chemical/physical vapor deposition steps minimizes the time-dependent degradation of surface activation that is inherent in multi-chamber techniques. Contamination and deposition irregularities are also minimized by conducting plasma activation and treatment phases in the same vacuum environment. An inductively coupled plasma driver allows for interchangeable treatment chambers. Atomic force microscopy confirms that silane deposition on PDMS gives much better surface quality than standard deposition methods, which yield a higher local roughness and pronounced irregularities in the surface.

  12. Lower body negative pressure chamber: Design and specifications for tilt-table mounting

    NASA Technical Reports Server (NTRS)

    Salamacha, Laura; Gundo, D.; Mulenburg, G. M.; Greenleaf, J. E.

    1995-01-01

    Specifications for a lower body negative pressure chamber for mounting on a tilting table are presented. The main plate is made from HEXEL honeycomb board 1.0 inch thick. The plate, supported at three edges, will be subjected to a uniform pressure differential of -4.7 lb/sq in. A semi-cylindrical Plexiglass top (chamber) is attached to the main plate; the pressure within the chamber will be about 10lb/sq in during operation. The stresses incurred by the main plate with this partial vacuum were calculated. All linear dimensions are in inches.

  13. Note: A single-chamber tool for plasma activation and surface functionalization in microfabrication

    SciTech Connect

    Bowman, Adam J.; Scherrer, Joseph R.; Reiserer, Ronald S.

    2015-06-15

    We present a simple apparatus for improved surface modification of polydimethylsiloxane (PDMS) microfluidic devices. A single treatment chamber for plasma activation and chemical/physical vapor deposition steps minimizes the time-dependent degradation of surface activation that is inherent in multi-chamber techniques. Contamination and deposition irregularities are also minimized by conducting plasma activation and treatment phases in the same vacuum environment. An inductively coupled plasma driver allows for interchangeable treatment chambers. Atomic force microscopy confirms that silane deposition on PDMS gives much better surface quality than standard deposition methods, which yield a higher local roughness and pronounced irregularities in the surface.

  14. Better vacuum by removal of diffusion-pump-oil contaminants

    NASA Technical Reports Server (NTRS)

    Buggele, A. E.

    1975-01-01

    The complex problem of why large space simulation chambers do not realize true ultimate vacuum was investigated. Some contaminating factors affecting diffusion pump performance were identified, and some advances in vacuum distillation-fractionation technology were achieved which resulted in a two-decade-or-more lower ultimate pressure. Data are presented to show the overall or individual contaminating effects of commonly used phthalate ester plasticizers of 390 to 530 molecular weight on diffusion pump performance. Methods for removing contaminants from diffusion pump silicone oil during operation and for reclaiming contaminated oil by high-vacuum molecular distillation are described. Conceptual self-cleansing designs and operating procedures are proposed for modifying large diffusion pumps into high-efficiency distillation devices. The potential exists for application of these technological advancements to other disciplines, such as medicine, biomedical materials, metallurgy, refining, and chemical (diffusion-enrichment) processing.

  15. Experimental system for drilling simulated lunar rock in ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Roepke, W. W.

    1975-01-01

    An experimental apparatus designed for studying drillability of hard volcanic rock in a simulated lunar vacuum of 5 x 10 to the minus 10th power torr is described. The engineering techniques used to provide suitable drilling torque inside the ultrahigh vacuum chamber while excluding all hydrocarbon are detailed. Totally unlubricated bearings and gears were used to better approximate the true lunar surface conditions within the ultrahigh vacuum system. The drilling system has a starting torque of 30 in-lb with an unloaded running torque of 4 in-lb. Nominal torque increase during drilling is 4.5 in-lb or a total drilling torque of 8.5 in-lb with a 100-lb load on the drill bit at 210 rpm. The research shows conclusively that it is possible to design operational equipment for moderate loads operating under UHV conditions without the use of sealed bearings or any need of lubricants whatsoever.

  16. Vacuum melting and mechanical testing of simulated lunar glasses

    NASA Technical Reports Server (NTRS)

    Carsley, J. E.; Blacic, J. D.; Pletka, B. J.

    1992-01-01

    Lunar silicate glasses may possess superior mechanical properties compared to terrestrial glasses because the anhydrous lunar environment should prevent hydrolytic weakening of the strong Si-O bonds. This hypothesis was tested by melting, solidifying, and determining the fracture toughness of simulated mare and highlands composition glasses in a high vacuum chamber. The fracture toughness, K(IC), of the resulting glasses was obtained via microindentation techniques. K(IC) increased as the testing environment was changed from air to a vacuum of 10 exp -7 torr. However, this increase in toughness may not result solely from a reduction in the hydrolytic weakening effect; the vacuum-melting process produced both the formation of spinel crystallites on the surfaces of the glass samples and significant changes in the compositions which may have contributed to the improved K(IC).

  17. Thermal Vacuum Control Systems Options for Test Facilities

    NASA Technical Reports Server (NTRS)

    Marchetti, John

    2008-01-01

    This presentation suggests several Thermal Vacuum System (TVAC) control design approach methods for TVAC facilities. Over the past several years many aerospace companies have or are currently upgrading their TVAC testing facilities whether it be by upgrading old equipment or purchasing new. In doing so they are updating vacuum pumping and thermal capabilities of their chambers as well as their control systems. Although control systems are sometimes are considered second to the vacuum or thermal system upgrade process, they should not be taken lightly and must be planned and implemented with the equipment it is to control. Also, emphasis should be placed on how the operators will use the system as well as the requirements of "their" customers. Presented will be various successful methods of TVAC control systems from Programmable Logic Controller (PLC) based to personal computer (PC) based control.

  18. Solar heated vacuum flask

    SciTech Connect

    Posnansky, M.

    1980-04-08

    The wall of a protective jacket of a vacuum flask, containing a double-walled vessel whose walls are permeable to solar radiation , includes parts capable of being swung open. These parts and a wall part situated between them each have a reflective coating. The reflective surfaces of these coatings, viewed in crosssection, extend along a parabola when the movable wall parts are opened out, so that incident solar radiation is collected in the core zone of the vessel. A solar-radiation absorbing member may be disposed in this core zone, E.G., a metal tube having a black outer surface. Liquid contents of such a vacuum flask can be heated by means of solar energy.

  19. Vacuum tool manipulator

    DOEpatents

    Zollinger, William T.

    1993-01-01

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

  20. An automated vacuum system

    SciTech Connect

    Atkins, W.H. ); Vaughn, G.D. ); Bridgman, C. )

    1991-01-01

    Software tools available with the Ground Test Accelerator (GTA) control system provide the capability to express a control problem as a finite state machine. System states and transitions are expressed in terms of accelerator parameters and actions are taken based on state transitions. This is particularly useful for sequencing operations which are modal in nature or are unwieldy when implemented with conventional programming. State diagrams are automatically translated into code which is executed by the control system. These tools have been applied to the vacuum system for the GTA accelerator to implement automatic sequencing of operations. With a single request, the operator may initiate a complete pump-down sequence. He can monitor the progress and is notified if an anomaly occurs requiring intervention. The operator is not required to have detailed knowledge of the vacuum system and is protected from taking inappropriate actions. 1 ref., 6 figs.

  1. Can vacuum energy gravitate?

    NASA Astrophysics Data System (ADS)

    Prasad Datta, Dhurjati

    1995-03-01

    In this essay we discuss an interesting recent development in semiclassical gravity. Using an improved Born-Oppenheimer approximation, the semiclassical reduction of the Wheeler-DeWitt equation turns out to give important insights into the nature and the level of validity of the semi-classical Einstein equations (SCEE). Back reactions from the quantized matter fields in SCEE are shown to be completely determined by adiabatically induced geometricU(N) gauge potentials. The finite energy from the vacuum polarization, in particular, is found to be intimately related to the ‘magnetic’ type geometric gauge potential. As a result the vacuum energy in a universe emerging from a ‘source-free’ flat simply-connected superspace is gauge equivalent to zero, leading to some dramatic consequences.

  2. Integrated structure vacuum tube

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Kerwin, W. J. (Inventor)

    1976-01-01

    High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Anode and grid members are formed using thin films of refractory metal. Electron flow in the tubes is between grid elements from cathode to anode as in a conventional three-dimensional tube.

  3. Vacuum tool manipulator

    DOEpatents

    Zollinger, W.T.

    1993-11-23

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm. 6 figures.

  4. Small rocket flowfield diagnostic chambers

    NASA Technical Reports Server (NTRS)

    Morren, Sybil; Reed, Brian

    1993-01-01

    Instrumented and optically-accessible rocket chambers are being developed to be used for diagnostics of small rocket (less than 440 N thrust level) flowfields. These chambers are being tested to gather local fluid dynamic and thermodynamic flowfield data over a range of test conditions. This flowfield database is being used to better understand mixing and heat transfer phenomena in small rockets, influence the numerical modeling of small rocket flowfields, and characterize small rocket components. The diagnostic chamber designs include: a chamber design for gathering wall temperature profiles to be used as boundary conditions in a finite element heat flux model; a chamber design for gathering inner wall temperature and static pressure profiles; and optically-accessible chamber designs, to be used with a suite of laser-based diagnostics for gathering local species concentration, temperature, density, and velocity profiles. These chambers were run with gaseous hydrogen/gaseous oxygen (GH2/GO2) propellants, while subsequent versions will be run on liquid oxygen/hydrocarbon (LOX/HC) propellants. The purpose, design, and initial test results of these small rocket flowfield diagnostic chambers are summarized.

  5. Fast-response cloud chamber

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.

    1977-01-01

    Wall structure keeps chambers at constant, uniform temperature, yet allows them to be cooled rapidly if necessary. Wall structure, used in fast-response cloud chamber, has surface heater and coolant shell separated by foam insulation. It is lightweight and requires relatively little power.

  6. Beam Window for Pressure Chambers

    NASA Technical Reports Server (NTRS)

    Bransford, J. W.; Austin, J. G., Jr.

    1985-01-01

    Window resists products of combustion experiments. Sodium chloride window seals over chamber pressures from 0.1 to 13.8 MPa while absorbing minimal energy from CO2 laser beam that passes through it into chamber. Window inexpensive and easily replacable.

  7. Chamber Music: Skills and Teamwork.

    ERIC Educational Resources Information Center

    Villarrubia, Charles

    2000-01-01

    Focuses on the benefits of participating in chamber music ensembles, such as the development of a heightened level of awareness, and considers the role of the music educator/conductor. Provides tools and exercises that teachers can introduce to chamber music players to improve their rehearsals and performances. (CMK)

  8. LRL 25-inch Bubble Chamber

    DOE R&D Accomplishments Database

    Alvarez, L. W.; Gow, J. D.; Barrera, F.; Eckman, G.; Shand, J.; Watt, R.; Norgren, D.; Hernandez, H. P.

    1964-07-08

    The recently completed 25-inch hydrogen bubble chamber combines excellent picture quality with a fast operating cycle. The chamber has a unique optical system and is designed to take several pictures each Bevatron pulse, in conjunction with the Bevatron rapid beam ejection system.

  9. Ion chamber based neutron detectors

    DOEpatents

    Derzon, Mark S; Galambos, Paul C; Renzi, Ronald F

    2014-12-16

    A neutron detector with monolithically integrated readout circuitry, including: a bonded semiconductor die; an ion chamber formed in the bonded semiconductor die; a first electrode and a second electrode formed in the ion chamber; a neutron absorbing material filling the ion chamber; and the readout circuitry which is electrically coupled to the first and second electrodes. The bonded semiconductor die includes an etched semiconductor substrate bonded to an active semiconductor substrate. The readout circuitry is formed in a portion of the active semiconductor substrate. The ion chamber has a substantially planar first surface on which the first electrode is formed and a substantially planar second surface, parallel to the first surface, on which the second electrode is formed. The distance between the first electrode and the second electrode may be equal to or less than the 50% attenuation length for neutrons in the neutron absorbing material filling the ion chamber.

  10. An ellipsometer with variable angle of incidence for studies in ultrahigh vacuum

    NASA Technical Reports Server (NTRS)

    Walter, H. U.; Weitzenkamp, L. A.; Peters, P. N.

    1974-01-01

    The windows for the vacuum chamber are incorporated into the optical bench system by means of flexible bellows which allow measurements to be made over a large range of angle of incidence, one of which is chosen so that maximum sensitivity is obtained. The principal angle of incidence was determined, and straightforward corrections for strain birefringence of vacuum chamber windows were made. Atomically clean surfaces of sodium chloride and lithium fluoride were investigated to verify the performance of the system. Submonolayer and monolayer coverage of water on these surfaces could be detected. On cleavage planes of NaCl, a first monolayer of adsorbed water is complete at about one torr only.

  11. Review of vacuum systems for x-ray lithography light sources

    SciTech Connect

    Schuchman, J.C.

    1990-01-01

    This paper will review and give a status report on vacuum systems for X-Ray lithography light sources. It will include conventional machines and compact machines (machines using superconducting magnets). The vacuum systems will be described and compared with regard to basic machine parameters, pumping systems, types of pumps, chamber design and material, gauging and diagnostics, and machine performane. 23 refs., 8 figs., 1 tab.

  12. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOEpatents

    Brown, I.G.; MacGill, R.A.; Galvin, J.E.; Ogletree, D.F.; Salmeron, M.

    1998-11-24

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing. 8 figs.

  13. Miniature pulsed vacuum arc plasma gun and apparatus for thin-film fabrication

    DOEpatents

    Brown, Ian G.; MacGill, Robert A.; Galvin, James E.; Ogletree, David F.; Salmeron, Miquel

    1998-01-01

    A miniature (dime-size in cross-section) vapor vacuum arc plasma gun is described for use in an apparatus to produce thin films. Any conductive material can be layered as a film on virtually any substrate. Because the entire apparatus can easily be contained in a small vacuum chamber, multiple dissimilar layers can be applied without risk of additional contamination. The invention has special applications in semiconductor manufacturing.

  14. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  15. Thermal System Upgrade of the Space Environment Simulation Test Chamber

    NASA Technical Reports Server (NTRS)

    Desai, Ashok B.

    1997-01-01

    The paper deals with the refurbishing and upgrade of the thermal system for the existing thermal vacuum test facility, the Space Environment Simulator, at NASA's Goddard Space Flight Center. The chamber is the largest such facility at the center. This upgrade is the third phase of the long range upgrade of the chamber that has been underway for last few years. The first phase dealt with its vacuum system, the second phase involved the GHe subsystem. The paper describes the considerations of design philosophy options for the thermal system; approaches taken and methodology applied, in the evaluation of the remaining "life" in the chamber shrouds and related equipment by conducting special tests and studies; feasibility and extent of automation, using computer interfaces and Programmable Logic Controllers in the control system and finally, matching the old components to the new ones into an integrated, highly reliable and cost effective thermal system for the facility. This is a multi-year project just started and the paper deals mainly with the plans and approaches to implement the project successfully within schedule and costs.

  16. Proton beam monitor chamber calibration.

    PubMed

    Gomà, C; Lorentini, S; Meer, D; Safai, S

    2014-09-01

    The first goal of this paper is to clarify the reference conditions for the reference dosimetry of clinical proton beams. A clear distinction is made between proton beam delivery systems which should be calibrated with a spread-out Bragg peak field and those that should be calibrated with a (pseudo-)monoenergetic proton beam. For the latter, this paper also compares two independent dosimetry techniques to calibrate the beam monitor chambers: absolute dosimetry (of the number of protons exiting the nozzle) with a Faraday cup and reference dosimetry (i.e. determination of the absorbed dose to water under IAEA TRS-398 reference conditions) with an ionization chamber. To compare the two techniques, Monte Carlo simulations were performed to convert dose-to-water to proton fluence. A good agreement was found between the Faraday cup technique and the reference dosimetry with a plane-parallel ionization chamber. The differences-of the order of 3%-were found to be within the uncertainty of the comparison. For cylindrical ionization chambers, however, the agreement was only possible when positioning the effective point of measurement of the chamber at the reference measurement depth-i.e. not complying with IAEA TRS-398 recommendations. In conclusion, for cylindrical ionization chambers, IAEA TRS-398 reference conditions for monoenergetic proton beams led to a systematic error in the determination of the absorbed dose to water, especially relevant for low-energy proton beams. To overcome this problem, the effective point of measurement of cylindrical ionization chambers should be taken into account when positioning the reference point of the chamber. Within the current IAEA TRS-398 recommendations, it seems advisable to use plane-parallel ionization chambers-rather than cylindrical chambers-for the reference dosimetry of pseudo-monoenergetic proton beams. PMID:25109620

  17. Understand vacuum-system fundamentals

    SciTech Connect

    Martin, G.R. ); Lines, J.R. ); Golden, S.W. )

    1994-10-01

    Crude vacuum unit heavy vacuum gas-oil (HVGO) yield is significantly impacted by ejector-system performance, especially at conditions below 20 mmHg absolute pressure. A deepcut vacuum unit, to reliably meet the yields, calls for proper design of all the major pieces of equipment. Ejector-system performance at deepcut vacuum column pressures may be independently or concurrently affected by: atmospheric column overflash, stripper performance or cutpoint; vacuum column top temperature and heat balance; light vacuum gas-oil (LVGO) pumparound entrainment to the ejector system; cooling-water temperature; motive steam pressure; non-condensible loading, either air leakage or cracked light-end hydrocarbons; condensible hydrocarbons; intercondenser or aftercondenser fouling ejector internal erosion or product build-up; and system vent back pressure. The paper discusses gas-oil yields; ejector-system fundamentals; condensers; vacuum-system troubleshooting; process operations; and a case study of deepcut operations.

  18. All-metal aromatic clusters M4(2-) (M = B, Al, and Ga). Are π-electrons distortive or not?

    PubMed

    Poater, Jordi; Feixas, Ferran; Bickelhaupt, F Matthias; Solà, Miquel

    2011-12-14

    The π-electrons in benzene, the quintessential aromatic molecule, were previously shown to be distortive, i.e., they prefer localized double bonds alternating with single bonds. It is the σ-electrons that force the double bonds to delocalize, leading to a regular, D(6h) geometry. Herein, we computationally investigate the double-bond localizing or delocalizing propensities of σ- and π-electrons in the archetypal all-metal aromatic cluster Al(4)(2-) and its second- and fourth-period analogs B(4)(2-) and Ga(4)(2-), using Kohn-Sham molecular orbital (MO) theory at BP86/TZ2P in combination with quantitative bond energy decomposition analyses (EDA). We compare the three all-metal aromatic clusters with the structurally related organic species C(4)H(4)(2+), C(4)H(4), and C(4)H(4)(2-). Our analyses reveal that the π-electrons in the group-13 M(4)(2-) molecules have a weak preference for localizing the double bonds. Instead, the σ-electrons enforce the regular D(4h) equilibrium geometry with delocalized double bonds. PMID:22011729

  19. Vacuum compatible miniature CCD camera head

    DOEpatents

    Conder, Alan D.

    2000-01-01

    A charge-coupled device (CCD) camera head which can replace film for digital imaging of visible light, ultraviolet radiation, and soft to penetrating x-rays, such as within a target chamber where laser produced plasmas are studied. The camera head is small, capable of operating both in and out of a vacuum environment, and is versatile. The CCD camera head uses PC boards with an internal heat sink connected to the chassis for heat dissipation, which allows for close(0.04" for example) stacking of the PC boards. Integration of this CCD camera head into existing instrumentation provides a substantial enhancement of diagnostic capabilities for studying high energy density plasmas, for a variety of military industrial, and medical imaging applications.

  20. Prototype of a tubeless vacuum insulated accelerator

    NASA Astrophysics Data System (ADS)

    Boggia, A.; Brautti, G.; Raino, A.; Stagno, V.; Ceci, N.; Valentino, V.; Variale, V.

    1996-02-01

    The construction of a small prototype of a new kind of Cockroft-Walton accelerator is in progress. The onion-wise disposal of the capacitor plates allows a high-gradient compact machine, as well as the assurance of reliability. This kind of machine can overcome the problem of having an accelerating column of high perveance. In fact, because of its peculiar electromechanical structure, the whole high voltage generator can be settled inside a vacuum chamber and then an electron beam can be accelerated directly by the capacitor plates of the voltage multipliers. The scaled-up version of this machine seems to be particularly suited for high-current, high-efficiency applications, like FEL, ion acceleration for plasma heating or containment. The status report of the experiment will be presented.