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Sample records for 15-t pulsed solenoid

  1. LPI: pulsed solenoid for positron focusing in LIL

    Photographic Service

    1993-01-01

    The solenoid for the initial focusing of the positrons emerging from the conversion target is mounted inside the vacuum, immediately after the target. Pulsed with a current of 6 kA for some 7 microseconds, it produces a longitudinal magnetic field of 1.5 T.

  2. Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

    Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

    2011-04-01

    A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

  3. Plasma shape control by pulsed solenoid on laser ion source

    Sekine, M. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Ikeda, S. [Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); RIKEN, Wako, Saitama 351-0198 (Japan); Romanelli, M. [Cornell University, Ithaca, NY 14850 (United States); Kumaki, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Waseda University, Shinjuku, Tokyo 169-0072 (Japan); Fuwa, Y. [RIKEN, Wako, Saitama 351-0198 (Japan); Kyoto University, Uji, Kyoto 611-0011 (Japan); Kanesue, T. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Hayashizaki, N. [Tokyo Institute of Technology, Meguro-ku, Tokyo 2-12-1 (Japan); Lambiase, R. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Okamura, M. [RIKEN, Wako, Saitama 351-0198 (Japan); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2015-09-21

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  4. Plasma shape control by pulsed solenoid on laser ion source

    Sekine, M.; Ikeda, S.; Romanelli, M.; Kumaki, M.; Fuwa, Y.; Kanesue, T.; Hayashizaki, N.; Lambiase, R.; Okamura, M.

    2015-09-01

    A Laser ion source (LIS) provides high current heavy ion beams with a very simple mechanical structure. Plasma is produced by a pulsed laser ablation of a solid state target and ions are extracted by an electric field. However, it was difficult to manipulate the beam parameters of a LIS, since the plasma condition could only be adjusted by the laser irradiation condition. To enhance flexibility of LIS operation, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The experimentally obtained current profile was satisfactorily controlled by the pulsed magnetic field. This approach may also be useful to reduce beam emittance of a LIS.

  5. Laser accelerated protons captured and transported by a pulse power solenoid

    Burris-Mog, T.; Harres, K.; Nürnberg, F.; Busold, S.; Bussmann, M.; Deppert, O.; Hoffmeister, G.; Joost, M.; Sobiella, M.; Tauschwitz, A.; Zielbauer, B.; Bagnoud, V.; Herrmannsdoerfer, T.; Roth, M.; Cowan, T. E.

    2011-12-01

    Using a pulse power solenoid, we demonstrate efficient capture of laser accelerated proton beams and the ability to control their large divergence angles and broad energy range. Simulations using measured data for the input parameters give inference into the phase-space and transport efficiencies of the captured proton beams. We conclude with results from a feasibility study of a pulse power compact achromatic gantry concept. Using a scaled target normal sheath acceleration spectrum, we present simulation results of the available spectrum after transport through the gantry.

  6. A single-solenoid pulsed-magnet system for single-crystal scattering studies.

    Islam, Zahirul; Capatina, Dana; Ruff, Jacob P C; Das, Ritesh K; Trakhtenberg, Emil; Nojiri, Hiroyuki; Narumi, Yasuo; Welp, Ulrich; Canfield, Paul C

    2012-03-01

    We present a pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies with the magnetic field applied on or close to the scattering plane. The apparatus consists of a single large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields close to ~30 T with a zero-to-peak-field rise time of ~2.9 ms are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6°) on the entrance and exit sides of the magnet bore by virtue of a novel double-funnel insert. This instrument will facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using split-pair and narrow-opening solenoid magnets. Furthermore, it offers a practical solution for preserving optical access in future higher-field pulsed magnets.

  7. Impact Of The Pulse Width Modulation On The Temperature Distribution In The Armature Of A Solenoid Valve

    Goraj, R.

    2015-12-01

    In order to estimate the inductive power set in the armature of the high-speed solenoid valve (HSV) during the open loop control (OLC) using pulse width modulation (PWM) an analytical explicit formula has been derived. The simplifications taken both in the geometry and in the physical behavior of the HSV were described. The inductive power was calculated for different boundary conditions and shown as a function of the frequency of the coil current. The power set in the armature was used as an input to the thermal calculation. The thermal calculation had an objective to estimate the time dependent temperature distribution in the armature of the HSV. All the derivation steps were presented and the influence of different boundary conditions was shown and discussed. The increase of the temperature during the heating with inductive power has been evaluated both in the core and on the side surface of the HSV.

  8. Impact Of The Pulse Width Modulation On The Temperature Distribution In The Armature Of A Solenoid Valve

    Goraj R.

    2015-12-01

    Full Text Available In order to estimate the inductive power set in the armature of the high-speed solenoid valve (HSV during the open loop control (OLC using pulse width modulation (PWM an analytical explicit formula has been derived. The simplifications taken both in the geometry and in the physical behavior of the HSV were described. The inductive power was calculated for different boundary conditions and shown as a function of the frequency of the coil current. The power set in the armature was used as an input to the thermal calculation. The thermal calculation had an objective to estimate the time dependent temperature distribution in the armature of the HSV. All the derivation steps were presented and the influence of different boundary conditions was shown and discussed. The increase of the temperature during the heating with inductive power has been evaluated both in the core and on the side surface of the HSV.

  9. Central Solenoid

    2002-01-01

    The Central Solenoid (CS) is a single layer coil wound internally in a supporting cylinder housed in the cryostat of the Liquid Argon Calorimeter. It was successfully tested at Toshiba in December 2000 and was delivered to CERN in September 2001 ready for integration in the LAr Calorimeter in 2003. An intermediate test of the chimney and proximity cryogenics was successfully performed in June 2002.

  10. COMPENSATION OF DETECTOR SOLENOID IN SUPER-B

    Nosochkov, Yuri; Bertsche, Kirk; Sullivan, Michael; /SLAC

    2011-06-02

    The SUPER-B detector solenoid has a strong 1.5 T field in the Interaction Region (IR) area, and its tails extend over the range of several meters. The main effect of the solenoid field is coupling of the horizontal and vertical betatron motion which must be corrected in order to preserve the small design beam size at the Interaction Point. The additional effects are orbit and dispersion caused by the angle between the solenoid and beam trajectories. The proposed correction system provides local compensation of the solenoid effects independently for each side of the IR. It includes 'bucking' solenoids to remove the solenoid field tails and a set of skew quadrupoles, dipole correctors and anti-solenoids to cancel linear perturbations to the optics. Details of the correction system are presented.

  11. Solenoid-Simulation Circuit

    Simon, R. A.

    1986-01-01

    Electrical properties of solenoids imitated for tests of control circuits. Simulation circuit imitates voltage and current responses of two engine-controlling solenoids. Used in tests of programs of digital engine-control circuits, also provides electronic interface with circuits imitating electrical properties of pressure sensors and linear variable-differential transformers. Produces voltages, currents, delays, and discrete turnon and turnoff signals representing operation of solenoid in engine-control relay. Many such circuits used simulating overall engine circuitry.

  12. ATLAS Solenoid Integration

    Ruber, R

    Last month the central solenoid was installed in the barrel cryostat, which it shares with the liquid argon calorimeter. Figure 1: Some members of the solenoid and liquid argon teams proudly pose in front of the barrel cryosat, complete with detector and magnet. Some two years ago the central solenoid arrived at CERN after being manufactured and tested in Japan. It was kept in storage until last October when it was finally moved to the barrel cryostat integration area. Here a position survey of the solenoid (with respect to the cryostat's inner warm vessel) was performed. Figure 2: The alignment survey by Dirk Mergelkuhl and Aude Wiart. (EST-SU) At the start of the New Year the solenoid was moved to the cryostat insertion stand. Figure 3: The solenoid on the insertion stand, with Akira Yamamoto the solenoid designer and project leader. Figure 4: Taka Kondo, ATLAS Japan spokesperson, and Shoichi Mizumaki, Toshiba project engineer for the ATLAS solenoid, celebrate the insertion. Aft...

  13. Inserting the CMS solenoid

    Maximilien Brice

    2005-01-01

    The huge superconducting solenoid for CMS is inserted into the cryostat barrel. CMS uses the world's largest thin solenoid, in terms of energy stored, and is 12 m long, with a diameter of 6 m and weighing 220 tonnes. When turned on the magnet will produce a field strength of 4 T using superconducting niobium-titanium material at 4.5 K.

  14. ATLAS solenoid operates underground

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. Teams monitoring the cooling and powering of the ATLAS solenoid in the control room. The solenoid was cooled down to 4.5 K from 17 to 23 May. The first current was established the same evening that the solenoid became cold and superconductive. 'This makes the ATLAS Central Solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas!', said Takahiko Kondo, professor at KEK. Though the current was limited to 1 kA, the cool-down and powering of the solenoid was a major milestone for all of the control, cryogenic, power and vacuum systems-a milestone reached by the hard work and many long evenings invested by various teams from ATLAS, all of CERN's departments and several large and small companies. Since the Central Solenoid and the barrel liquid argon (LAr) calorimeter share the same cryostat vacuum vessel, this achievement was only possible in perfe...

  15. The ATLAS central solenoid

    Yamamoto, A; Ruber, R; Doi, Y; Haruyama, T; Haug, F; ten Kate, H; Kawai, M; Kondo, T; Kondo, Y; Metselaar, J; Mizumaki, S; Olesen, G; Pavlov, O; Ravat, S; Sbrissa, E; Tanaka, K; Taylor, T; Yamaoka, H

    2008-01-01

    The ATLAS detector at the CERN LHC is equipped with a superconducting magnet system consisting of three large toroids and a solenoid. The 2.3 m diameter, 5.3 m long solenoid is located at the heart of the experiment where it provides a 2 T field for spectrometry of the particles emanating from the interaction of the counter-rotating beams of hadrons. As the electromagnetic calorimeter of the experiment is situated outside the solenoid, the coil must be as transparent as possible to traversing particles. The magnet, which was designed at KEK, incorporates progress in technology coming from the development of previous solenoids of this type, in particular that of a new type of reinforced superconductor addressing the requirement of transparency. Special attention has been paid to ensuring reliability and ease of operation of the magnet, through the application of sufficiently conservative guidelines for the mechanical and electrical design, stringent testing during manufacture, and a comprehensive commissioning...

  16. The CMS superconducting solenoid

    Maximilien Brice

    2004-01-01

    The huge solenoid that will generate the magnetic field for the CMS experiment at the LHC is shown stored in the assembly hall above the experimental cavern. The solenoid is made up of five pieces totaling 12.5 m in length and 6 m in diameter. It weighs 220 tonnes and will produce a 4 T magnetic field, 100 000 times the strength of the Earth's magnetic field, storing enough energy to melt 18 tonnes of gold.

  17. Laser ion source with solenoid field

    Kanesue, Takeshi; Fuwa, Yasuhiro; Kondo, Kotaro; Okamura, Masahiro

    2014-11-01

    Pulse length extension of highly charged ion beam generated from a laser ion source is experimentally demonstrated. The laser ion source (LIS) has been recognized as one of the most powerful heavy ion source. However, it was difficult to provide long pulse beams. By applying a solenoid field (90 mT, 1 m) at plasma drifting section, a pulse length of carbon ion beam reached 3.2 μs which was 4.4 times longer than the width from a conventional LIS. The particle number of carbon ions accelerated by a radio frequency quadrupole linear accelerator was 1.2 × 1011, which was provided by a single 1 J Nd-YAG laser shot. A laser ion source with solenoid field could be used in a next generation heavy ion accelerator.

  18. ATLAS Solenoid Integration

    Ruber, R

    Last month the central solenoid was installed in the barrel cryostat, which it shares with the liquid argon calorimeter. Some two years ago the central solenoid arrived at CERN after being manufactured and tested in Japan. It was kept in storage until last October when it was finally moved to the barrel cryostat integration area. Here a position survey of the solenoid (with respect to the cryostat's inner warm vessel) was performed. At the start of the New Year the solenoid was moved to the cryostat insertion stand. After a test insertion on 6th February and a few weeks of preparation work it was finally inserted on 27th February. A couple of hectic 24-hours/7-day weeks followed in order to connect all services in the cryostat bulkhead. But last Monday, 15th March, both warm flanges of the cryostat could be closed. In another week's time we expect to finish the connection of the cryogenic cooling lines and the superconducting bus lines with the external services. Then the cool-down and test will commence... ...

  19. Magnetic latching solenoid

    Marts, D.J.; Richardson, J.G.; Albano, R.K.; Morrison, J.L. Jr.

    1995-11-28

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized. 2 figs.

  20. Magnetic latching solenoid

    Marts, Donna J. (Idaho Falls, ID); Richardson, John G. (Idaho Falls, ID); Albano, Richard K. (Idaho Falls, ID); Morrison, Jr., John L. (Idaho Falls, ID)

    1995-01-01

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.

  1. LCLS Gun Solenoid Design Considerations

    Schmerge, John

    2010-12-10

    The LCLS photocathode rf gun requires a solenoid immediately downstream for proper emittance compensation. Such a gun and solenoid have been operational at the SSRL Gun Test Facility (GTF) for over eight years. Based on magnetic measurements and operational experience with the GTF gun solenoid multiple modifications are suggested for the LCLS gun solenoid. The modifications include adding dipole and quadrupole correctors inside the solenoid, increasing the bore to accommodate the correctors, decreasing the mirror plate thickness to allow the solenoid to move closer to the cathode, cutouts in the mirror plate to allow greater optical clearance with grazing incidence cathode illumination, utilizing pancake coil mirror images to compensate the first and second integrals of the transverse fields and incorporating a bipolar power supply to allow for proper magnet standardization and quick polarity changes. This paper describes all these modifications plus the magnetic measurements and operational experience leading to the suggested modifications.

  2. INVESTIGATION ON THE DYNAMIC RESPONSE PERFORMANCE OF A NOVEL THREE-WAY SOLENOID VALVE

    Li Wei; Su Ling; Wang Ying; Zhou Longbao; Liu Quanbing

    2006-01-01

    Objective A novel high-speed three-way solenoid valve is developed, which is used for the common-rail injection system equipped on DME powered engine. In order to improve the dynamic response performance of the three-way solenoid. Methods Experimental studies have been conducted to investigate the effects of spool stroke, drive voltage, negative demagnetizing pulse and two drive schemes on the dynamic response performance of the three-way solenoid valve. Results The results show that the dynamic response performance of the three-way solenoid valve can be remarkably improved by shortening the spool stroke and increasing the drive voltage. Simultaneously, the difference between the response time of closing valve and that of opening valve decreases. At each different drive voltage, there exists an optimal negative demagnetizing pulse corresponding to the same positive exciting pulse. At this optimal pulse,the dynamic response performance of the three-way solenoid valve is the best. In addition, the high drive voltage can lead to the smaller optimal negative demagnetizing pulse. It is also indicated from the experiments that the dynamic response performance of the three-way solenoid valve is better when the NO. 1 drive scheme is adopted. The lower drive voltage results in the larger difference between the dynamic response performances for the two drive schemes.Conclusion The dynamic response performance of a novel three-way solenoid valve is good.

  3. Inauguration of the CMS solenoid

    Maximilien Brice

    2005-01-01

    In early 2005 the final piece of the CMS solenoid magnet arrived, marked by this ceremony held in the CMS assembly hall at Cessy, France. The solenoid is made up of five pieces totaling 12.5 m in length and 6 m in diameter. Weighing 220 tonnes, it will produce a 4 T magnetic field, 100 000 times the strength of the Earth's magnetic field and store enough energy to melt 18 tonnes of gold.

  4. Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-01-01

    Using laser accelerated protons or ions for various applications - for example in particle therapie or short-pulse radiographic diagnostics - requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. The scaling shows that above a few MeV a solenoid needs to be pulsed or super-conducting, whereas the quadrupoles can remai...

  5. ATLAS Solenoid placed in its final position

    2004-01-01

    The ATLAS superconducting solenoid during one of the transport operations. Securely attached to the overhead crane, the solenoid is situated in front of the opening to the liquid-argon electromagnetic calorimeter, where it will soon be inserted.

  6. Magnetic design constraints of helical solenoids

    Lopes, M. L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Krave, S. T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Tompkins, J. C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yonehara, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Flanagan, G. [Muons Inc., Batavia, IL (United States); Kahn, S. A. [Muons Inc., Batavia, IL (United States); Melconian, K. [Texas A & M Univ., College Station, TX (United States)

    2015-01-30

    Helical solenoids have been proposed as an option for a Helical Cooling Channel for muons in a proposed Muon Collider. Helical solenoids can provide the required three main field components: solenoidal, helical dipole, and a helical gradient. In general terms, the last two are a function of many geometric parameters: coil aperture, coil radial and longitudinal dimensions, helix period and orbit radius. In this paper, we present design studies of a Helical Solenoid, addressing the geometric tunability limits and auxiliary correction system.

  7. Effect of solenoidal magnetic field on drifting laser plasma

    Takahashi, Kazumasa; Okamura, Masahiro; Sekine, Megumi; Cushing, Eric; Jandovitz, Peter

    2013-04-01

    An ion source for accelerators requires to provide a stable waveform with a certain pulse length appropriate to the application. The pulse length of laser ion source is easy to control because it is expected to be proportional to plasma drifting distance. However, current density decay is proportional to the cube of the drifting distance, so large current loss will occur under unconfined drift. We investigated the stability and current decay of a Nd:YAG laser generated copper plasma confined by a solenoidal field using a Faraday cup to measure the current waveform. It was found that the plasma was unstable at certain magnetic field strengths, so a baffle was introduced to limit the plasma diameter at injection and improve the stability. Magnetic field, solenoid length, and plasma diameter were varied in order to find the conditions that minimize current decay and maximize stability.

  8. GigaGauss solenoidal magnetic field inside bubbles excited in under-dense plasma

    Lécz, Zs.; Konoplev, I. V.; Seryi, A.; Andreev, A.

    2016-10-01

    This paper proposes a novel and effective method for generating GigaGauss level, solenoidal quasi-static magnetic fields in under-dense plasma using screw-shaped high intensity laser pulses. This method produces large solenoidal fields that move with the driving laser pulse and are collinear with the accelerated electrons. This is in contrast with already known techniques which rely on interactions with over-dense or solid targets and generates radial or toroidal magnetic field localized at the stationary target. The solenoidal field is quasi-stationary in the reference frame of the laser pulse and can be used for guiding electron beams. It can also provide synchrotron radiation beam emittance cooling for laser-plasma accelerated electron and positron beams, opening up novel opportunities for designs of the light sources, free electron lasers, and high energy colliders based on laser plasma acceleration.

  9. First Generation Final Focusing Solenoid For NDCX-I

    Seidl, P. A.; Waldron, W.

    2011-11-09

    This report describes the prototype final focus solenoid (FFS-1G), or 1st generation FFS. In order to limit eddy currents, the solenoid winding consists of Litz wire wound on a non-conductive G-10 tube. For the same reason, the winding pack was inserted into an electrically insulating, but thermally conducting Polypropylene (Cool- Poly© D1202) housing and potted with highly viscous epoxy (to be able to wick the single strands of the Litz wire). The magnet is forced-air cooled through cooling channels. The magnet was designed for water cooling, but he cooling jacket cracked, and therefore cooling (beyond natural conduction and radiation) was exclusively by forced air. Though the design operating point was 8 Tesla, for the majority of running on NDCX-1 it operated up to about 5 Tesla. This was due mostly from limitations of voltage holding at the leads, where discharges at higher pulsed current damaged the leads. Generation 1 was replaced by the 2nd generation solenoid (FFS-2G) about a year later, which has operated reliably up to 8 Tesla, with a better lead design and utilizes water cooling. At this point, FFS-1G was used for plasma source R&D by LBNL and PPPL. The maximum field for those experiments was reduced to 3 Tesla due to continued difficulty with the leads and because higher field was not essential for those experiments. The pulser for the final focusing solenoid is a SCR-switched capacitor bank which produces a half-sine current waveform. The pulse width is ~800us and a charge voltage of 3kV drives ~20kA through the magnet producing ~8T field.

  10. Advancing Non-Solenoidal Startup on the Pegasus ST

    Reusch, J. A.; Barr, J. L.; Bodner, G. M.; Bongard, M. W.; Burke, M. G.; Fonck, R. J.; Pachicano, J. L.; Perry, J. M.; Richner, N. J.; Rodriguez Sanchez, C.; Schlossberg, D. J.

    2016-10-01

    The Pegasus experiment utilizes compact, edge-localized current sources (Ainj 2 - 4 cm2, Iinj 10 kA, Vinj 1 kV) for non-solenoidal local helicity injection (LHI) startup. Recent campaigns are comparing two injector geometries that vary the differing relative contributions of DC helicity input and non-solenoidal inductive voltages. A predictive 0-D model that treats the plasma as a resistive element with time-varying inductance and enforces Ip limits from Taylor relaxation was tested with inward growth of the plasma current channel using injectors on the outboard midplane. Strong inductive drive arises from plasma shape evolution and poloidal field (PF) induction. A major unknown in the model is the resistive dissipation, and hence the electron confinement. Te (R) profile measurements in LHI show centrally-peaked Te > 100 eV while the plasma is coupled to the injectors, suggesting LHI confinement is not strongly stochastic. A second campaign utilizes new injectors in the lower divertor region. This geometry trades subtler relaxation field programming and reduced PF induction for higher HI rates. Present efforts are developing relaxation methods at high BT, with relaxation at BT , inj > 0.15 T achieved to date via higher Iinj and PF manipulation. Conceptual design studies of coaxial helicity injection (CHI) and ECH heating systems for Pegasus have been initiated to explore direct comparison of LHI to CHI with and without ECH assist. Supported by US DOE Grants DE-FG02-96ER54375, DE-SC0006928.

  11. Central Solenoid Insert Technical Specification

    Martovetsky, Nicolai N [ORNL; Smirnov, Alexandre [ORNL

    2011-09-01

    The US ITER Project Office (USIPO) is responsible for the ITER central solenoid (CS) contribution to the ITER project. The Central Solenoid Insert (CSI) project will allow ITER validation the appropriate lengths of the conductors to be used in the full-scale CS coils under relevant conditions. The ITER Program plans to build and test a CSI to verify the performance of the CS conductor. The CSI is a one-layer solenoid with an inner diameter of 1.48 m and a height of 4.45 m between electric terminal ends. The coil weight with the terminals is approximately 820 kg without insulation. The major goal of the CSI is to measure the temperature margin of the CS under the ITER direct current (DC) operating conditions, including determining sensitivity to load cycles. Performance of the joints, ramp rate sensitivity, and stability against thermal or electromagnetic disturbances, electrical insulation, losses, and instrumentation are addressed separately and therefore are not major goals in this project. However, losses and joint performance will be tested during the CSI testing campaign. The USIPO will build the CSI that will be tested at the Central Solenoid Model Coil (CSMC) Test Facility at the Japan Atomic Energy Agency (JAEA), Naka, Japan. The industrial vendors (the Suppliers) will report to the USIPO (the Company). All approvals to proceed will be issued by the Company, which in some cases, as specified in this document, will also require the approval of the ITER Organization. Responsibilities and obligations will be covered by respective contracts between the USIPO, called Company interchangeably, and the industrial Prime Contractors, called Suppliers. Different stages of work may be performed by more than one Prime Contractor, as described in this specification. Technical requirements of the contract between the Company and the Prime Contractor will be covered by the Fabrication Specifications developed by the Prime Contractor based on this document and approved by

  12. CERN tests largest superconducting solenoid magnet

    2006-01-01

    "CERN's Compacts Muon Solenoid (CMS) - the world's largest superconducting solenoid magnet - has reached full field in testing. The instrument is part of the proton-proton Large Hadron Collider (LHC) project, located in a giant subterranean chamber at Cessy on the Franco-Swiss border." (1 page)

  13. Non-Solenoidal Tokamak Startup via Inboard Local Helicity Injection on the Pegasus ST

    Perry, J. M.; Barr, J. L.; Bodner, G. M.; Bongard, M. W.; Fonck, R. J.; Pachicano, J. L.; Reusch, J. A.; Rodriguez Sanchez, C.; Richner, N. J.; Schlossberg, D. J.

    2016-10-01

    Local helicity injection (LHI) is a non-solenoidal startup technique utilizing small injectors at the plasma edge to source current along helical magnetic field lines. Unstable injected current streams relax to a tokamak-like configuration with high toroidal current multiplication. Flexible placement of injectors permits tradeoffs between helicity injection rate, poloidal field induction, and magnetic geometry requirements for initial relaxation. Experiments using a new set of large-area injectors in the lower divertor explore the efficacy of high-field-side (HFS) injection. The increased area (4 cm2) current source is functional up to full Pegasus toroidal field (BT , inj = 0.23 T). However, relaxation to a tokamak state is increasingly frustrated for BT , inj > 0.15 T with uniform vacuum vertical field. Paths to relaxation at increased field include: manipulation of vacuum poloidal field geometry; increased injector current; and plasma initiation with outboard injectors, subsequently transitioning to divertor injector drive. During initial tests of HFS injectors, achieved Vinj was limited to 600 V by plasma-material interactions on the divertor plate, which may be mitigated by increasing injector elevation. In experiments with helicity injection as the dominant current drive Ip 0.13 MA has been attained, with T̲e > 100 eV and ne 1019 m-3. Extrapolation to full BT, longer pulse length, and Vinj 1 kV suggest Ip > 0.25 MA should be attainable in a plasma dominated by helicity drive. Work supported by US DOE Grant DE-FG02-96ER54375.

  14. ATLAS's superconducting solenoid takes up position

    2004-01-01

    The ATLAS superconducting solenoid was moved to its final destination on 16 January. It has taken up position opposite the ATLAS liquid argon barrel cryostat, which will house the electromagnetic calorimeter. All that remains to do now is to slide it into the insulation vacuum, this will be done in the next few weeks. Built by Toshiba, under responsibility of KEK in Japan, the central solenoid is 2.4 metres in diameter, 5.3 metres long and weighs 5.5 tonnes. "It will provide an axial magnetic field of 2 Tesla that will deflect particles inside the inner detector," as Roger Ruber, on-site project coordinator, explains. The inner detector, which consists of three sub-detectors, will be installed inside the solenoid later. The solenoid during one of the transport operations. Securely attached to the overhead travelling crane, the solenoid is situated in front of the opening to the liquid argon calorimeter, it will be inserted soon.

  15. Performance of solenoids vs. quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-01-01

    Using laser accelerated protons or ions for various applications - for example in particle therapie or short-pulse radiographic diagnostics - requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. The scaling shows that above a few MeV a solenoid needs to be pulsed or super-conducting, whereas the quadrupoles can remain conventional. The transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al.\\cite{yan2009}.

  16. ITER Central Solenoid Module Fabrication

    Smith, John [General Atomics, San Diego, CA (United States)

    2016-09-23

    The fabrication of the modules for the ITER Central Solenoid (CS) has started in a dedicated production facility located in Poway, California, USA. The necessary tools have been designed, built, installed, and tested in the facility to enable the start of production. The current schedule has first module fabrication completed in 2017, followed by testing and subsequent shipment to ITER. The Central Solenoid is a key component of the ITER tokamak providing the inductive voltage to initiate and sustain the plasma current and to position and shape the plasma. The design of the CS has been a collaborative effort between the US ITER Project Office (US ITER), the international ITER Organization (IO) and General Atomics (GA). GA’s responsibility includes: completing the fabrication design, developing and qualifying the fabrication processes and tools, and then completing the fabrication of the seven 110 tonne CS modules. The modules will be shipped separately to the ITER site, and then stacked and aligned in the Assembly Hall prior to insertion in the core of the ITER tokamak. A dedicated facility in Poway, California, USA has been established by GA to complete the fabrication of the seven modules. Infrastructure improvements included thick reinforced concrete floors, a diesel generator for backup power, along with, cranes for moving the tooling within the facility. The fabrication process for a single module requires approximately 22 months followed by five months of testing, which includes preliminary electrical testing followed by high current (48.5 kA) tests at 4.7K. The production of the seven modules is completed in a parallel fashion through ten process stations. The process stations have been designed and built with most stations having completed testing and qualification for carrying out the required fabrication processes. The final qualification step for each process station is achieved by the successful production of a prototype coil. Fabrication of the first

  17. HB+ inserted into the CMS Solenoid

    Tejinder S. Virdee, CERN

    2006-01-01

    The first half of the barrel hadron calorimeter (HB+) has been inserted into the superconducting solenoid of CMS, in preparation for the magnet test and cosmic challenge. The operation went smoothly, lasting a couple of days.

  18. Solenoid and Synchrotron radiation effects in CLIC

    Dalena, B; Tomás, R; Angal-Kalinin, D

    2010-01-01

    The emission of Synchrotron Radiation in the CLIC BDS is one of the major limitations of the machine performance. An extensive revision of this phenomenon is presented with special emphasis on the Interaction point (IP) solenoid.

  19. Compact muon solenoid magnet reaches full field

    2006-01-01

    Scientist of the U.S. Department of Energy in Fermilab and collaborators of the US/CMS project announced that the world's largest superconducting solenoid magnet has reached full field in tests at CERN. (1 apge)

  20. Arrival of the ATLAS solenoid from Japan

    Patrice Loïez

    2001-01-01

    Photo 01: L. to r.: Photo 01: L. to r.: Herman ten Kate (Magnet Project Leader), Takahiko Kondo (KEK, Solenoid Project Leader), Peter Jenni (Spokesperson). Photo 02: (truck on the right side) with the LAr barrel calorimeter cryostat (also built in Japan) on the left side. From left to right are the following ATLAS people: Herman ten Kate (Magnet Project Leader), Marzio Nessi (Technical Coordinator), Takahiko Kondo (KEK, Solenoid Project Leader), Peter Jenni (Spokesperson)

  1. Behavior of moving plasma in solenoidal magnetic field in a laser ion source

    Ikeda, S., E-mail: ikeda.s.ae@m.titech.ac.jp [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0108 (Japan); Takahashi, K. [Department of Electrical Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2137 (Japan); Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States); Horioka, K. [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502 (Japan)

    2016-02-15

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

  2. Behavior of moving plasma in solenoidal magnetic field in a laser ion source

    Ikeda, S.; Takahashi, K.; Okamura, M.; Horioka, K.

    2016-02-01

    In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.

  3. Performance of a multi-axis ionization chamber array in a 1.5 T magnetic field.

    Smit, K; Kok, J G M; Lagendijk, J J W; Raaymakers, B W

    2014-04-07

    At the UMC Utrecht a prototype MR-linac has been installed. The system consists of an 8 MV Elekta linear accelerator and a 1.5 T Philips MRI system. This paper investigates the performance of the IC PROFILER™, a multi-axis ionization chamber array, in a 1.5 T magnetic field. The influence of the magnetic field on the IC PROFILER™ reproducibility, dose response linearity, pulse rate frequency dependence, power to electronics, panel orientation and ionization chamber shape were investigated. The linearity, reproducibility, pulse rate frequency dependence, panel orientation and ionization chamber shape are unaffected by the magnetic field. When the measurements results are normalized to the centre reference chamber, the measurements can commence unaltered. Orientation of the ionization chambers in the magnetic field is of importance, therefore caution must be taken when comparing or normalizing results from several different axes. IC PROFILER™ dose profiles were compared with film dose profiles obtained simultaneously in the MR-linac. Deviation between the film and the IC PROFILER™ data was caused by the noise in the film, indicating correct performance of the IC PROFILER™ in the transverse 1.5 T magnetic field.

  4. Performance of a multi-axis ionization chamber array in a 1.5 T magnetic field

    Smit, K.; Kok, J. G. M.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2014-04-01

    At the UMC Utrecht a prototype MR-linac has been installed. The system consists of an 8 MV Elekta linear accelerator and a 1.5 T Philips MRI system. This paper investigates the performance of the IC PROFILER™, a multi-axis ionization chamber array, in a 1.5 T magnetic field. The influence of the magnetic field on the IC PROFILER™ reproducibility, dose response linearity, pulse rate frequency dependence, power to electronics, panel orientation and ionization chamber shape were investigated. The linearity, reproducibility, pulse rate frequency dependence, panel orientation and ionization chamber shape are unaffected by the magnetic field. When the measurements results are normalized to the centre reference chamber, the measurements can commence unaltered. Orientation of the ionization chambers in the magnetic field is of importance, therefore caution must be taken when comparing or normalizing results from several different axes. IC PROFILER™ dose profiles were compared with film dose profiles obtained simultaneously in the MR-linac. Deviation between the film and the IC PROFILER™ data was caused by the noise in the film, indicating correct performance of the IC PROFILER™ in the transverse 1.5 T magnetic field.

  5. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    Ikeda, S., E-mail: ikeda.s.ae@m.titech.ac.jp [Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 216-8502 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0108 (Japan); Kumaki, M. [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0108 (Japan); Kanesue, T.; Okamura, M. [Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

    2016-02-15

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  6. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  7. Central Solenoid On-surface Test

    Ruber, R

    2004-01-01

    A full scale on-surface test of the central solenoid has been performed before its final installation in the ATLAS cavern starting in November. The successful integration of the central solenoid into the barrel cryostat, as reported in the March 2004 ATLAS eNews, was hardly finished when testing started. After a six-week period to cool down the LAr calorimeter, the solenoid underwent a similar procedure. Cooling it down to 4.6 Kelvin from room temperature took just over five and a half days. Cold and superconducting, it was time to validate the functionality of the control and safety systems. These systems were largely the same as the systems to be used in the final underground installation, and will be used not only for the solenoid and toroid magnets, but parts of it also for other LHC experiments. This solenoid test was the first occasion to test the system functionality in a real working environment. Several days were spent to fine tune the systems, especially the critical safety system, which turned out...

  8. Performance of solenoids versus quadrupoles in focusing and energy selection of laser accelerated protons

    Hofmann, Ingo

    2013-04-01

    Using laser accelerated protons or ions for various applications—for example in particle therapy or short-pulse radiographic diagnostics—requires an effective method of focusing and energy selection. We derive an analytical scaling for the performance of a solenoid compared with a doublet/triplet as function of the energy, which is confirmed by TRACEWIN simulations. Generally speaking, the two approaches are equivalent in focusing capability, if parameters are such that the solenoid length approximately equals its diameter. The scaling also shows that this is usually not the case above a few MeV; consequently, a solenoid needs to be pulsed or superconducting, whereas the quadrupoles can remain conventional. It is also important that the transmission of the triplet is found only 25% lower than that of the equivalent solenoid. Both systems are equally suitable for energy selection based on their chromatic effect as is shown using an initial distribution following the RPA simulation model by Yan et al. [Phys. Rev. Lett. 103, 135001 (2009PRLTAO0031-900710.1103/PhysRevLett.103.135001].

  9. Field Mapping System for Solenoid Magnet

    Park, K. H.; Jung, Y. K.; Kim, D. E.; Lee, H. G.; Park, S. J.; Chung, C. W.; Kang, B. K.

    2007-01-01

    A three-dimensional Hall probe mapping system for measuring the solenoid magnet of PLS photo-cathode RF e-gun has been developed. It can map the solenoid field either in Cartesian or in cylindrical coordinate system with a measurement reproducibility better than 5 × 10-5 T. The system has three axis motors: one for the azimuthal direction and the other two for the x and z direction. This architecture makes the measuring system simple in fabrication. The magnetic center was calculated using the measured axial component of magnetic field Bz in Cartesian coordinate system because the accuracy of magnetic axis measurement could be improved significantly by using Bz, instead of the radial component of magnetic field Br. This paper describes the measurement system and summarizes the measurement results for the solenoid magnetic of PLS photo-cathode RF e-gun.

  10. THE ANTI-SOLENOID COMPENSATION OF THE CLIC DETECTOR SOLENOID USING IRSYN

    Appleby, R B

    2011-01-01

    The detector solenoid of CLIC causes a range of aberrations on the beam at the interaction point, particularly due to its overlap with the final focus magnets. These effects are corrected using antisolenoid correction coils on the final quadrupole before the collision point. In this note, we use the interaction region beam dynamics code IRSYN to compute the impact of the SiD solenoid on the beam and benchmark the anti-solenoid correction. We find the correction is achieved, with a small residual amount of beam aberration which is correctable using the beam delivery system. This provides a validation of the correction and a benchmark of IRSYN to existing codes.

  11. Alternative Methods for Field Corrections in Helical Solenoids

    Lopes, M. L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Krave, S. T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Tompkins, J. C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Yonehara, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Flanagan, G. [Muons Inc., Batavia, IL (United States); Kahn, S. A. [Muons Inc., Batavia, IL (United States); Melconian, K. [Texas A & M Univ., College Station, TX (United States)

    2015-05-01

    Helical cooling channels have been proposed for highly efficient 6D muon cooling. Helical solenoids produce solenoidal, helical dipole, and helical gradient field components. Previous studies explored the geometric tunability limits on these main field components. In this paper we present two alternative correction schemes, tilting the solenoids and the addition of helical lines, to reduce the required strength of the anti-solenoid and add an additional tuning knob.

  12. First Operation of the Central Solenoid

    Ruber, R.

    2006-01-01

    A new phase for the ATLAS collaboration started with the first operation of a completed sub-system: the Central Solenoid. It was cooled down from the 17th to 23th May 2006, and the first kA was put into it the same evening as it was cold and superconductive. That makes our solenoid the very first cold and superconducting magnet to be operated in the LHC underground areas. The Central Solenoid in its final position at the heart of ATLAS. The coil current (red line) and voltage (blue line) showing the operation at nominal current of 7.73 kA for a magnetic field of 2.0 T and the subsequent successful commissioning up to 8 kAT The cool down and powering of the solenoid was a major milestone for all control, cryogenic, power and vacuum systems and was achieved in perfect collaboration with the liquid argon detector with which it shares the Barrel Cryostat. Powering up to nominal current had to wait until the last week of July when the End-Cap Calorimeters were in closed position. The Tile Barrel and E...

  13. Bent Solenoids with Superimposed Dipole Fields

    Meinke, Rainer, B.; Goodzeit, Carl, L.

    2000-03-21

    A conceptual design and manufacturing technique were developed for a superconducting bent solenoid magnet with a superimposed dipole field that would be used as a dispersion device in the cooling channel of a future Muon Collider. The considered bent solenoid is equivalent to a 180° section of a toroid with a major radius of ~610 mm and a coil aperture of ~416 mm. The required field components of this magnet are 4 tesla for the solenoid field and 1 tesla for the superimposed dipole field. A magnet of this size and shape, operating at these field levels, has to sustain large Lorentz forces resulting in a maximum magnetic pressure of about 2,000 psi. A flexible round mini-cable with 37 strands of Cu-NbTi was selected as the superconductor. Detailed magnetic analysis showed that it is possible to obtain the required superimposed dipole field by tilting the winding planes of the solenoid by ~25°. A complete structural analysis of the coil support system and the helium containment vessel under thermal, pressure, and Lorentz force loads was carried out using 3D finite element models of the structures. The main technical issues were studied and solutions were worked out so that a highly reliable magnet of this type can be produced at an affordable cost.

  14. Successful mapping of the solenoid magnet

    Aleksa, M.

    The ATLAS solenoid coil is about 5.3m long, has a diameter of 2.5m and is designed to deliver a magnetic field of approximately 2T for the ATLAS inner detector. The superconducting solenoid coil has been integrated inside the LAr barrel cryostat and was installed at its final position inside the cavern in November 2005. This summer - after completion of the extended barrel calorimeters and before the installation of the inner detector - the end cap calorimeters (LAr end caps and Tile extended barrels) were moved for the first time into their final position in order to create conditions as close as possible to final for the solenoid tests and for mapping the field inside the solenoid bore. Design and construction of the mapping machine The requirement on the absolute precision of the field measurements are 0.05% on the field integrals seen by particles; if this is achieved the momentum error coming from insufficient knowledge of the magnetic field will be negligible compared to the error stemming from the inn...

  15. Fabrication and mechanical performance of the ATLAS central solenoid

    Mizumaki, S; Kobayashi, T; Yamaoka, H; Kondo, Y; Kawai, M; Doi, Y; Haruyama, T; Mine, S; Takano, H; Yamamoto, A; Kondo, T; ten Kate, H H J

    2002-01-01

    Fabrication of the central solenoid for ATLAS detector in the CERN- LHC project was completed, and the performance test has been successfully carried out in Japan. The solenoid has arrived at CERN to be assembled with the LAr calorimeter. This paper describes the fabrication and mechanical, performance of the ATLAS central solenoid. (10 refs).

  16. On the Suitability of a Solenoid Horn for the ESS Neutrino Superbeam

    Olvegård, Maja; Ruber, R; Ziemann, R; Koutchouk, J -P

    2015-01-01

    The European Spallation Source (ESS), now under construction in Lund, Sweden, offers unique opportunities for experimental physics, not only in neutron science but potentially in particle physics. The ESS neutrino superbeam project plans to use a 5 MW proton beam from the ESS linac to generate a high intensity neutrino superbeam, with the final goal of detecting leptonic CP-violation in an underground megaton Cherenkov water detector. The neutrino production requires a second target station and a complex focusing system for the pions emerging from the target. The normal-conducting magnetic horns that are normally used for these applications cannot accept the 2.86 ms long proton pulses of the ESS linac, which means that pulse shortening in an accumulator ring would be required. That, in turn, requires H- operation in the linac to accommodate the high intensity. As an attractive alternative, we investigate the possibility of using superconducting solenoids for the pion focusing. This solenoid horn system needs ...

  17. Efficient transfer of positrons from a buffer-gas-cooled accumulator into an orthogonally oriented superconducting solenoid for antihydrogen studies

    Comeau, D; Fitzakerley, D; George, M C; Hessels, E A; Storry, C H; Weel, M; Grzonka, D; Oelert, W; Gabrielse, G; Kalra, R; Kolthammer, W S; McConnell, R; Richerme, P; Mullers, A; Walz, J

    2012-01-01

    Positrons accumulated in a room-temperature buffer-gas-cooled positron accumulator are efficiently transferred into a superconducting solenoid which houses the ATRAP cryogenic Penning trap used in antihydrogen research. The positrons are guided along a 9 m long magnetic guide that connects the central field lines of the 0.15 T field in the positron accumulator to the central magnetic field lines of the superconducting solenoid. Seventy independently controllable electromagnets are required to overcome the fringing field of the large-bore superconducting solenoid. The guide includes both a 15 degrees upward bend and a 105 degrees downward bend to account for the orthogonal orientation of the positron accumulator with respect to the cryogenic Penning trap. Low-energy positrons ejected from the accumulator follow the magnetic field lines within the guide and are transferred into the superconducting solenoid with nearly 100% efficiency. A 7 m long 5 cm diameter stainless-steel tube and a 20 mm long, 1.5 mm diamet...

  18. Reference Design of the Mu2e Detector Solenoid

    Feher, S; Brandt,, J; Cheban, S; Coleman, R; Dhanaraj, N; Fang, I; Lamm, M; Lombardo, V; Lopes, M; Miller, J; Ostojic, R ,; Orris, D; Page, T; Peterson, T; Tang, Z; Wands, R

    2014-01-01

    The Mu2e experiment at Fermilab has been approved by the Department of Energy to proceed developing the preliminary design. Integral to the success of Mu2e is the superconducting solenoid system. One of the three major solenoids is the Detector Solenoid that houses the stopping target and the detectors. The goal of the Detector Solenoid team is to produce detailed design specifications that are sufficient for vendors to produce the final design drawings, tooling and fabrication procedures and proceed to production. In this paper we summarize the Reference Design of the Detector Solenoid.

  19. A new muon-pion collection and transport system design using superconducting solenoids based on CSNS

    Xiao, Ran; Liu, Yan-Fen; Xu, Wen-Zhen; Ni, Xiao-Jie; Pan, Zi-Wen; Ye, Bang-Jiao

    2016-05-01

    A new muon and pion capture system is proposed for the China Spallation Neutron Source (CSNS), currently under construction. Using about 4% of the pulsed proton beam (1.6 GeV, 4 kW and 1 Hz) of CSNS to bombard a cylindrical graphite target inside a superconducting solenoid, both surface muons and pions can be acquired. The acceptance of this novel capture system - a graphite target wrapped up by a superconducting solenoid - is larger than the normal muon beam lines using quadrupoles at one side of the separated muon target. The muon and pion production at different capture magnetic fields was calculated using Geant4. The bending angle of the capture solenoid with respect to the proton beam was also optimized in simulation to achieve more muons and pions. Based on the layout of the muon experimental area reserved at the CSNS project, a preliminary muon beam line was designed with multi-purpose muon spin rotation areas (surface, decay and low-energy muons). Finally, high-flux surface muons (108/s) and decay muons (109/s) simulated by G4beamline will be available at the end of the decay solenoid based on the first phase of CSNS. This collection and transport system will be a very effective beam line at a proton current of 2.5 μA. Supported by National Natural Science Foundation of China (11527811)

  20. Fractional flux quanta in superconducting solenoids

    Sá de Melo, C. A. R.

    1996-03-01

    The quantization of flux quanta in superconductors is revisited and analyzed in a new topology. The topology is that of a superconducting wire that winds N times around a fixed axis and has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. In this case, fractional flux quanta can be measured through the center of the solenoid, provided that its cross-section radius is small enough. The Little-Parks experiment for an identical topology is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0.

  1. Bistable (latching) solenoid actuated propellant isolation valve

    Wichmann, H.; Deboi, H. H.

    1979-01-01

    The design, fabrication, assembly and test of a development configuration bistable (latching) solenoid actuated propellant isolation valve suitable for the control hydrazine and liquid fluorine to an 800 pound thrust rocket engine is described. The valve features a balanced poppet, utilizing metal bellows, a hard poppet/seat interface and a flexure support system for the internal moving components. This support system eliminates sliding surfaces, thereby rendering the valve free of self generated particles.

  2. Cross section of the CMS solenoid

    Tejinder S. Virdee, CERN

    2005-01-01

    The pictures show a cross section of the CMS solenoid. One can see four layers of the superconducting coil, each of which contains the superconductor (central part, copper coloured - niobium-titanium strands in a copper coating, made into a "Rutherford cable"), surrounded by an ultra-pure aluminium as a magnetic stabilizer, then an aluminium alloy as a mechanical stabilizer. Besides the four layers there is an aluminium mechanical piece that includes pipes that transport the liquid helium.

  3. D0 Solenoid Upgrade Project: Vacuum Pumping Calculations for the D0 Solenoid

    Rucinski, R.; /Fermilab

    1993-08-02

    This engineering note documents the calculations done to determine the vacuum pumping speed for the D-Zero solenoid. The raw calculations are attached. A summary of the results are listed. The vacuum pumping speed of the solenoid is determined by the conductance of the pumping path. At higher pressure ranges during initial pumpdown, the conductances will be rather high. Calculations were not done for the transient pumpdown period, only the steady state type pumping situation. The pressure is assumed to be on the order of 10E-7 torr. This is the free molecular flow regime based on Knudsen number. This pressure regime is also where the pumping speed would be least. The conductances were calculated based on pumping helium gas at a temperature of 300 Kelvin. The total conductance of the pumping path from the solenoid to the inlet of the turbomolecular pump is 11.8 L/s. The effective pumping speed of a 1000 L/s turbo pump attached to this pumping path is 11.7 L/s. The minimum required pumping speed for design purposes was set at 4.3 L/s. This value was arrived at by assuming a warm leak size (10E-8 atm-cc/sec) was not detected during fabrication of the solenoid. It is then assumed that the leak leaks cold liquid helium into the vacuum space. With this leak rate, a 4.3 L/s pumping speed would be able to maintain a 2 x 10E-7 torr pressure in the solenoid vacuum jacket. The solenoid would be able to be operated with this small leak with continuous pumping.

  4. Beam collimation and transport of quasineutral laser-accelerated protons by a solenoid field

    Harres, K.; Alber, I.; Tauschwitz, A.; Bagnoud, V.; Daido, H.; Günther, M.; Nürnberg, F.; Otten, A.; Schollmeier, M.; Schütrumpf, J.; Tampo, M.; Roth, M.

    2010-02-01

    This article reports about controlling laser-accelerated proton beams with respect to beam divergence and energy. The particles are captured by a pulsed high field solenoid with a magnetic field strength of 8.6 T directly behind a flat target foil that is irradiated by a high intensity laser pulse. Proton beams with energies around 2.3 MeV and particle numbers of 1012 could be collimated and transported over a distance of more than 300 mm. In contrast to the protons the comoving electrons are strongly deflected by the solenoid field. They propagate at a submillimeter gyroradius around the solenoid's axis which could be experimentally verified. The originated high flux electron beam produces a high space charge resulting in a stronger focusing of the proton beam than expected by tracking results. Leadoff particle-in-cell simulations show qualitatively that this effect is caused by space charge attraction due to the comoving electrons. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications such as postacceleration by conventional accelerator structures.

  5. Performance Characterization of a Solenoid-type Gas Valve for the H- Magnetron Source at FNAL

    Sosa, A. [Fermilab; Bollinger, D. S. [Fermilab; Karns, P. R. [Fermilab

    2016-09-06

    The magnetron-style H- ion sources currently in operation at Fermilab use piezoelectric gas valves to function. This kind of gas valve is sensitive to small changes in ambient temperature, which affect the stability and performance of the ion source. This motivates the need to find an alternative way of feeding H2 gas into the source. A solenoid-type gas valve has been characterized in a dedicated off-line test stand to assess the feasibility of its use in the operational ion sources. H- ion beams have been extracted at 35 keV using this valve. In this study, the performance of the solenoid gas valve has been characterized measuring the beam current output of the magnetron source with respect to the voltage and pulse width of the signal applied to the gas valve.

  6. Approximate theory the electromagnetic energy of solenoid in special relativity

    Prastyaningrum, I.; Kartikaningsih, S.

    2017-01-01

    Solenoid is a device that is often used in electronic devices. A solenoid is electrified will cause a magnetic field. In our analysis, we just focus on the electromagnetic energy for solenoid form. We purpose to analyze by the theoretical approach in special relativity. Our approach is begun on the Biot Savart law and Lorentz force. Special theory relativity can be derived from the Biot Savart law, and for the energy can be derived from Lorentz for, by first determining the momentum equation. We choose the solenoid form with the goal of the future can be used to improve the efficiency of the electrical motor.

  7. An elementary argument for the magnetic field outside a solenoid

    Pathak, Aritro

    2017-01-01

    The evaluation of the magnetic field inside and outside a uniform current density infinite solenoid of uniform cross-section is an elementary problem in classical electrodynamics that all undergraduate Physics students study. Symmetry properties of the cylinder and the judicious use of Ampere’s circuital law leads to correct results; however it does not explain why the field is non zero for a finite length solenoid, and why it vanishes as the solenoid becomes infinitely long. An argument is provided in Farley and Price (2001 Am. J. Phys. 69 751), explaining how the magnetic field behaves outside the solenoid and not too far from it, as a function of the length of the solenoid. A calculation is also outlined for obtaining the field just outside the circular cross section solenoid, in the classic text Classical Electrodynamics by Jackson, 3rd edn (John Wiley and Sons, Inc.), problems 5.3-5.5. The purpose of this paper is to provide an elementary argument for why the field becomes negligible as the length of the solenoid is increased. A quantitative analysis is provided for the field outside the solenoid, at radial distances large compared to the linear dimension of the solenoid cross section.

  8. Functional and genomic analyses of alpha-solenoid proteins.

    David Fournier

    Full Text Available Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others. While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/.

  9. Design and construction of a pulse magnetiser

    Garcia, M. M.; Gonzalez, F. J. G.; Avalos, E. C.; Rocha, G. G. L.; Llamazares, J. L. S.

    2005-10-01

    In the present paper we present the design and construction of a pulsed field magnetizer that has been set up at the IF-UASLP. The system is based on the discharge of the energy stored in a capacitor bank (C-total = 23.1 mF; U = 1/2CV(2) approximate to 2300 J) into a resistive double-layer copper solenoid supported by reinforcing glass fibers. This magnetizer is capable of generating pulsed magnetic field strengths up to 9.0 T, in a cylindrical volume of 17 mm diameter at the center of the solenoid, with a pulse duration of about 2.0 ms. The principle of operation of the magnetizer as well as the design of the field solenoid are described. A pick-up coil system combined with an electronic integrator is also available in the apparatus to monitor the shape of the field pulse, peak field, and pulse duration.

  10. First detector installed inside the ALICE solenoid...

    2006-01-01

    ALICE's emblematic red magnet welcomed its first detector on 23 September, when the array of seven Cherenkov detectors, named HMPID, was successfully installed. ALICE team members standing in front of the completed HMPID detector.The red magnet, viewed from its front opening. The HMPID unit, seen from the back (top right corner of photo) is placed on a frame and lifted onto a platform during the installation. After the installation of the ACORDE scintillator array and the muon trigger and tracking chambers, the ALICE collaboration fitted the first detector inside the solenoid. The HMPID, for High Momentum Particle Identification, was installed at the 2 o'clock position in the central and most external region of the space frame, just below the solenoid yoke. It will be used to extend the hadron identification capability of the ALICE experiment up to 5 GeV/c, thus complementing the reach of the other particle identification systems (ITS, TPC and TOF). The HMPID is a Ring Imaging Cherenkov (RICH) detector in a...

  11. Design of permanent magnetic solenoids for REGAE

    Gehrke, Tim

    2013-10-15

    The Relativistic Electron Gun for Atomic Exploration (REGAE) is a small linear accelerator at DESY in Hamburg, which produces short, low emittance electron bunches. It is originally designed and built for ultrafast electron diffraction (UED) within the framework of the Center for Free-Electron Laser Science (CFEL). Additionally, two future experiments are planned at REGAE. First, an external injection experiment for Laser Wakefield Acceleration (LWA) will be performed in the framework of the LAOLA collaboration (LAboratory fOr Laser- and beam-driven plasma Acceleration). This experiment will provide a method for the reconstruction of the electric field distribution within a linear plasma wakefield. Second, a time resolving high energy Transmission Electron Microscope (TEM) will be implemented. Among others it is designed to allow for living cell imaging. Both experiments require strong focusing magnets inside the new target chamber at REGAE. Permanent magnetic solenoids (PMSs) can provide the needed focusing strength due to their enormous surface current density, while having compact dimensions at the same time. The present thesis deals with the design of such strong focusing PMSs. Since short and strong solenoids, as required for REGAE, exhibit a distinct non-linearity, the induced emittance growth is relatively large. This emittance growth is investigated and minimized for different set-ups with axially and radially magnetized annular magnets. Furthermore a magnetic shielding is developed. Together with a mechanical lifting system it assures that magnetic leakage fields do not disturb experiments, where the PMSs are removed from the beamline.

  12. Residual magnetism holds solenoid armature in desired position

    Crawford, R. P.

    1967-01-01

    Holding solenoid uses residual magnetism to hold its armature in a desired position after excitation current is removed from the coil. Although no electrical power or mechanical devices are used, the solenoid has a low tolerance to armature displacement from the equilibrium position.

  13. A METHOD FOR PRODUCING A HIGH QUALITY SOLENOIDAL FIELD

    Feinberg, B.; Brown, I.G.; Halbach, K.; Kunkel, W.B.

    1981-01-01

    A relatively simple and inexpensive device is described which can be used to provide a highly homogeneous solenoidal magnetic field when the solenoid windings are inadequate. Design considerations and experimental measurements are presented. A field straightness of approximately 10{sup -4} radians has been achieved.

  14. Mu2e production solenoid cryostat conceptual design

    Nicol, T.H.; Kashikhin, V.V.; Page, T.M.; Peterson, T.J.; /Fermilab

    2011-06-01

    Mu2e is a muon-to-electron conversion experiment being designed by an international collaboration of more than 65 scientists and engineers from more than 20 research institutions for installation at Fermilab. The experiment is comprised of three large superconducting solenoid magnet systems, production solenoid (PS), transport solenoid (TS) and detector solenoid (DS). A 25 kW, 8 GeV proton beam strikes a target located in the PS creating muons from the decay of secondary particles. These muons are then focused in the PS and the resultant muon beam is transported through the TS towards the DS. The production solenoid presents a unique set of design challenges as the result of high radiation doses, stringent magnetic field requirements, and large structural forces. This paper describes the conceptual design of the PS cryostat and will include discussions of the vacuum vessel, thermal shield, multi-layer insulation, cooling system, cryogenic piping, and suspension system.

  15. Electroplated solenoid-type inductors for CMOS rf CO

    Nam, Chul; Choi, Wonseo; Chun, KukJin

    2000-10-01

    A Solenoid-type Inductors have been realized using electroplating technique mainly used for 2 Ghz band CMOS RF VCO applications. The integrated spiral inductor has low Q factor due to substrate loss and skin effects. And it also occupies large area compared to solenoid-type inductor. The direction of flux of the solenoid-type inductor is parallel to the substrate, which can lower substrate loss and other interference with integrated passive components. In this research, Solenoid-type inductors are simulated and modeled as equivalent circuit for CMOS RF VCO based on extracted S- parameters. The electroplated solenoid-type inductors are fabricated on both a standard silicon substrate and glass substrate by thick PR photolithography and copper electroplating. The achieved inductance varies range from 1 nH to 5 nH, and maximum Q factor over 10. The inductors are scheduled to be integrated on CMOS RF VCO with RF MEMS capacitor for future.

  16. A new muon-pion collection and transport system design using superconducting solenoids based on CSNS

    Xiao, Ran; Xu, Wenzhen; Ni, Xiaojie; Pan, Ziwen; Ye, Bangjiao

    2015-01-01

    A new muon and pion capture system was proposed at the under-conduction China Spallation Neutron Source (CSNS). Using about 4 % of the pulsed proton beam (1.6 GeV, 4 kW and 1 Hz) of CSNS to bombard a cylindrical graphite target inside a superconducting solenoid both surface muons and pions can be acquired. The acceptance of this novel capture system - a graphite target wrapped up by a superconducting solenoid - is larger than the normal muon beam lines using quadrupoles at one side of the separated muon target. The muon and pion production at different capture magnetic fields was calculated by Geant4, the bending angle of the capture solenoid with respect to the proton beam was also optimized in simulation to achieve more muons and pions and to reduce proton dosages to following beam elements. According to the layout of the muon experimental area reserved at the CSNS project, a preliminary muon beam line was designed with multi-propose muon spin rotation areas(surface, decay and low-energy muons). Finally, hi...

  17. Development and Comparison of Mechanical Structures for FNAL 15 T Nb$_3$Sn Dipole Demonstrator

    Novitski, I. [Fermilab; Zlobin, A. V. [Fermilab

    2016-11-08

    Main design challenges for 15 T accelerator magnets are large Lorentz forces at this field level. The large Lorentz forces generate high stresses in the coil and mechanical structure and, thus, need stress control to maintain them at the acceptable level for brittle Nb3Sn coils and other elements of magnet mechanical structure. To provide these conditions and achieve the design field in the FNAL 15 T dipole demonstrator, several mechanical structures have been developed and analysed. The possibilities and limitations of these designs are discussed in this paper

  18. Validation of Quench Simulation and Simulation of the TWIN Solenoid

    Pots, Rosalinde Hendrika

    2015-01-01

    For the Future Circular Collider at CERN a multi-purpose detector is proposed. The 6T TWIN Solenoid, a very large magnet system with a stored energy of 53 GJ, is being designed. It is important to protect the magnet against quenches in the system. Therefore several existing quench protection systems are evaluated and simulations have be performed on quenches in the TWIN Solenoid. The simulations on quenches in the TWIN Solenoid have been performed with promising results; the hotspot temperatures do not exceed 120 K and layer to layer voltages stay below 500 V. Adding quench heaters to the system might improve the quench protection system further.

  19. Note: A simple model for thermal management in solenoids.

    McIntosh, E M; Ellis, J

    2013-11-01

    We describe a model of the dynamical temperature evolution in a solenoid winding. A simple finite element analysis is calibrated by accurately measuring the thermally induced resistance change of the solenoid, thus obviating the need for accurate knowledge of the mean thermal conductivity of the windings. The model predicts quasi thermal runaway for relatively modest current increases from the normal operating conditions. We demonstrate the application of this model to determine the maximum current that can be safely applied to solenoids used for helium spin-echo measurements.

  20. The External Magnetic Field Created by the Superposition of Identical Parallel Finite Solenoids

    Lim, Melody Xuan

    2015-01-01

    Using superposition and numerical approximations of a published analytical expression for the magnetic field generated by a finite solenoid, we show that the magnetic field external to parallel identical solenoids can be nearly uniform and substantial, even when the solenoids have lengths that are large compared to their radii. We study two arrangements of solenoids---a ring of parallel solenoids whose surfaces are tangent to a common cylindrical surface and to nearest neighbours, and a large finite hexagonal array of parallel solenoids---and summarize how the magnitude and uniformity of the resultant external field depend on the solenoid length and distances between solenoids. We also report some novel results about single solenoids, e.g., that the energy stored in the internal magnetic field exceeds the energy stored in the spatially infinite external magnetic field for even short solenoids. These results should be broadly interesting to undergraduates learning about electricity and magnetism as novel examp...

  1. The Compact Muon Solenoid Detector Control System

    CERN. Geneva

    2012-01-01

    The Compact Muon Solenoid (CMS) is a CERN multi-purpose experiment that exploits the physics of the Large Hadron Collider (LHC). The Detector Control System (DCS) ensures a safe, correct and efficient experiment operation, contributing to the recording of high quality physics data. The DCS is programmed to automatically react to the LHC changes. CMS sub-detector’s bias voltages are set depending on the machine mode and particle beam conditions. A protection mechanism ensures that the sub-detectors are locked in a safe mode whenever a potentially dangerous situation exists. The system is supervised from the experiment control room by a single operator. A small set of screens summarizes the status of the detector from the approximately 6M monitored parameters. Using the experience of nearly two years of operation with beam the DCS automation software has been enhanced to increase the system efficiency. The automation allows now for configuration commands that can be used to automatically pre-configure hardwar...

  2. Solenoid-free plasma start-up in spherical tokamaks

    Raman, R.; Shevchenko, V. F.

    2014-10-01

    The central solenoid is an intrinsic part of all present-day tokamaks and most spherical tokamaks. The spherical torus (ST) confinement concept is projected to operate at high toroidal beta and at a high fraction of the non-inductive bootstrap current as required for an efficient reactor system. The use of a conventional solenoid in a ST-based fusion nuclear facility is generally believed to not be a possibility. Solenoid-free plasma start-up is therefore an area of extensive worldwide research activity. Solenoid-free plasma start-up is also relevant to steady-state tokamak operation, as the central transformer coil of a conventional aspect ratio tokamak reactor would be located in a high radiation environment but would be needed only during the initial discharge initiation and current ramp-up phases. Solenoid-free operation also provides greater flexibility in the selection of the aspect ratio and simplifies the reactor design. Plasma start-up methods based on induction from external poloidal field coils, helicity injection and radio frequency current drive have all made substantial progress towards meeting this important need for the ST. Some of these systems will now undergo the final stages of test in a new generation of large STs, which are scheduled to begin operations during the next two years. This paper reviews research to date on methods for inducing the initial start-up current in STs without reliance on the conventional central solenoid.

  3. An elementary argument for the magnetic field outside a solenoid

    Pathak, Aritro

    2016-01-01

    The evaluation of the magnetic field inside and outside a uniform current density infinite solenoid of uniform cross-section is an elementary problem in classical electrodynamics that all undergraduate Physics students study. Symmetry properties of the cylinder and the judicious use of Ampere's circuital law leads to correct results; however it does not explain why the field is non zero for a finite length solenoid, and why it vanishes as the solenoid becomes infinitely long. An argument is provided in (American Journal of Physics 69, 751 (2001)) by Farley and Price, explaining how the magnetic field behaves outside the solenoid and not too far from it, as a function of the length of the solenoid. A calculation is also outlined for obtaining the field just outside the circular cross section solenoid, in the classic text Classical Electrodynamics by J.D.Jackson, 3rd ed, (John Wiley and Sons, INC) Problems 5.3, 5.4, 5.5. The purpose of this letter is to provide an elementary argument for why the field becomes n...

  4. Clinical advantages of 3.0 T MRI over 1.5 T

    Willinek, Winfried A. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)], E-mail: winfried.willinek@ukb.uni-bonn.de; Schild, Hans H. [Department of Radiology, University of Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn (Germany)

    2008-01-15

    Since approval by the FDA in 2000, human MR imaging (MRI) at 3.0 T has been increasingly used in clinical practice. In spite of the potential technical challenges, a number of clinical advantages of 3.0 T MRI over 1.5 T have been identified in the recent years. This article reviews the benefits and the current knowledge of 3.0 T whole-body MRI from an evidence-based perspective and summarizes its clinical applications.

  5. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  6. Design Concept and Parameters of a 15 T $Nb_{3}Sn$ Dipole Demonstrator for a 100 TEV Hadron Collider

    Zlobin, A. V. [Fermilab; Andreev, N. [Fermilab; Barzi, E. [Fermilab; Kashikhin, V. V. [Fermilab; Novitski, I. [Fermilab

    2015-06-01

    FNAL has started the development of a 15 T $Nb_{3}Sn$ dipole demonstrator for a 100 TeV scale hadron collider. This paper describes the design concept and parameters of the 15 T $Nb_{3}Sn$ dipole demonstrator. The dipole magnetic, mechanical and quench protection concept and parameters are presented and discussed.

  7. Interdigital (Morton) neuroma: high-resolution MR imaging with a solenoid coil.

    Erickson, S J; Canale, P B; Carrera, G F; Johnson, J E; Shereff, M J; Gould, J S; Hyde, J S; Jesmanowicz, A

    1991-12-01

    Fifteen patients (17 feet) with symptoms suggestive of plantar interdigital neuroma underwent magnetic resonance (MR) imaging at 1.5 T with a solenoid forefoot coil with an 8-cm field of view. Surgery was subsequently performed on six feet. Fifteen interdigital masses were identified with MR imaging. Five of these, in feet that underwent surgery, were pathologically confirmed neuromas. In the remaining foot that underwent surgery, flexor tendon injury with probable inflammatory reaction was demonstrated with MR imaging but was interpreted as indeterminate for neuroma. No neuronal was identified at surgery, which otherwise confirmed the MR imaging findings. Neuromas were most conspicuous on T1-weighted images as foci of decreased signal intensity well demarcated from adjacent fat tissue. The lesions were poorly seen on T2-weighted images, where they appeared isointense or slightly hypointense to fat tissue in all cases. Prominent regions of increased signal intensity, presumably representing fluid in intermetatarsal bursae, were seen proximal to 10 of the 15 masses found with MR imaging.

  8. Heat Treatment Optimization of Rutherford Cable for a 15 T Nb3Sn Dipole Demonstrator

    Barzi, Emanuela [barzi@fnal.gov

    2016-12-22

    FNAL has been developing a 15 T Nb3Sn dipole demonstrator for a future Very High Energy pp Collider based on an optimized 60-mm aperture 4-layer “cos-theta” coil. To increase magnet efficiency, the coil was graded by using two cables with same 15 mm width and different thicknesses made of two different Restacked Rod Process (RRP®) wires. Due to the non-uniform field distribution in dipole coils the maximum field in the inner coil will reach 15-16 T, whereas the maximum field in the outer coil is 12-13 T. In preparation for the 15 T dipole coil reaction, heat treatment studies were performed on strands extracted from these cables with the goal of achieving the best coil performance in the corresponding magnetic fields. In particular, the effect of maximum temperature and time on the cable critical current was studied to take into account actual variations of these parameters during coil reaction. In parallel and in collaboration with OST, development was performed on optimizing Nb3Sn RRP® wire design and layout. Index Terms— Accelerator magnet, critical current density, Nb3Sn strand, Rutherford cable.

  9. Quench Analysis of the PANDA Target Spectrometer Solenoid

    Deelen, Nikkie

    2014-01-01

    A quench analysis of the PANDA Target Solenoid has been performed. The characteristic time of the fast discharge is $12\\ \\text{s}$. The peak temperature and peak voltage during a quench are $30\\ \\text{K}$ and $160\\ \\text{V}$ respectively. During a quench the energy stored in the magnetic field is mostly dissipated in the dump resistor. The slow discharge of the PANDA solenoid takes approximately $1950\\ \\text{s}$ during which nearly all the energy is dissipated in the diodes of the quench protection circuit.

  10. Note: An improved solenoid driver valve for miniature shock tubes.

    Lynch, P T

    2016-05-01

    A solenoid driver valve has been built to improve the operating performance of diaphragmless shock tubes, which are used for high pressure, high temperature chemical kinetics, and fluid mechanics studies. For shock tube driver application, the most important characteristics are those of sealing, strength, and quality of the generated shock waves and repeatability of opening characteristics and therefore subsequent post-shock conditions. The main features of the new driver valve are a face o-ring sealing design of the valve, the large internal volume, and through inserts near the solenoid core: adjustable opening characteristics of the valve.

  11. Measurement of liquid permittivity by solenoid self-resonance

    Getz, Patrick; Mazzeo, Brian

    2010-10-01

    Permittivity of a liquid is an important macroscopic property which is dependent on the composition and physical state of the liquid. Measurement of liquid permittivity is usually performed using a parallel-plate capacitor or terminated coaxial line. In this study, a solenoid surrounding a column of liquid is used to measure permittivity changes. The inductance of the solenoid is not greatly affected by permittivity and conductivity changes for small diameters. However, the self-capacitance is greatly affected by changing solution conditions. The self-resonance, due to the changing self-capacitance, thus reveals properties of the solution. This is demonstrated on a variety of liquids with varying permittivity and conductivity.

  12. Dispersion in a bent-solenoid channel with symmetric focusing

    Wang, Chun-xi [Argonne National Lab. (ANL), Argonne, IL (United States)

    2001-08-21

    Longitudinal ionization cooling of a muon beam is essential for muon colliders and will be useful for neutrino factories. Bent-solenoid channels with symmetric focusing has been considered for beam focusing and for generating the required dispersion in the ``emittance exchange'' scheme of longitudinal cooling. In this paper, we derive the Hamiltonian that governs the linear beam dynamics of a bent-solenoid channel, solve the single-particle dynamics, and give equations for determining the lattice functions, in particular, the dispersion functions.

  13. Measurement application for injector solenoid : measurement application for an injector solenoid in the Wärtsilä 46CR engine

    Ohls, Tony Conny Christoffer

    2012-01-01

    This thesis was commissioned by Wärtsilä Finland Services and concerns creating an application with LabVIEW that will measure key values from an injector solenoid intended for a Wärtsilä 46CR engine. The application created will analyse two signals that are sampled with a frequency of 100 000 Hz and based on these signals, the key values will be calculated. The key values are: the time it takes for a valve to start opening from the moment power is fed into the solenoid, the time it takes...

  14. Single breath hold 3D cardiac cine MRI using kat-ARC: preliminary results at 1.5T.

    Jeong, Daniel; Schiebler, Mark L; Lai, Peng; Wang, Kang; Vigen, Karl K; François, Christopher J

    2015-04-01

    Validation of a new single breath-hold, three-dimensional, cine balanced steady-state free precession (3D cine bSSFP) cardiac magnetic resonance (CMR) sequence for left ventricular function. CMR examinations were performed on fifteen patients and three healthy volunteers on a clinical 1.5T scanner using a two-dimensional (2D) cine balanced SSFP CMR sequence (2D cine bSSFP) followed by an investigational 3D cine bSSFP pulse sequence acquired within a single breath hold. Left ventricular end diastolic volume (LVEDV), end systolic volume (LVESV), ejection fraction (LVEF), and myocardial mass were independently segmented on a workstation by two experienced radiologists. Blood pool to myocardial contrast was evaluated in consensus using a Likert scale. Bland-Altman analysis was used to compare these quantitative and nominal measurements for the two sequences. The average acquisition time was significantly shorter for the 3D cine bSSFP than for 2D cine bSSFP (0.36 ± 0.03 vs. 8.5 ± 2.3 min) p = 0.0002. Bland-Altman analyses [bias and (limits of agreement)] of the data derived from these two methods revealed that the LVEF 0.9% (-4.7, 6.4), LVEDV 4.9 ml (-23.0, 32.8), LVESV -0.2 ml (-22.4, 21.9), and myocardial mass -0.4 g (-23.8, 23.0) were not significantly different. There was excellent intraclass correlation for intra-observer variability (0.981, 0.989, 0.997, 0.985) and inter-observer variability (0.903, 0.954, 0.970, 0.842) for LVEF, LVEDV, LVESV, and myocardial mass respectively. 3D cine bSSFP allows for accurate single breath-hold volumetric cine CMR which enables substantial improvements in scanner time efficiency without sacrificing diagnostic accuracy.

  15. 基于FPGA的电磁阀控制设计与研究%Solenoid Valve Control Design and Research Based on FPGA

    刘兴俊; 杨玉华; 贾兴中

    2016-01-01

    针对航空飞行器在飞行试验中需要精确控制滚控发动机电磁阀的难题,从电磁阀自身特点入手,设计了控制硬件电路并建立电磁阀门硬件电路灭弧电路响应时间模型,成功卸载60.5 V反向大电压,详细分析影响电磁阀的时间因素,同时也提出了基于FPGA的电磁阀可配置脉冲的实现方式。目前,该电磁阀控制设计已成功应用于地面发动机测试设备,具有较好的实时性、安全性和时间响应性能。%For aviation aircraft in the flight test,the precise control of the engine roller solenoid valve requires. Start⁃ing from its own characteristics solenoid valve control hardware circuit design,an interrupter arc response time mod⁃el of the solenoid valve hardware circuit is established,reverse large voltage 60.5 V successfully uninstalled,and the time factor of the solenoid valve analyzed. Based on FPGA implementations,solenoid valve can be configured by pulse matches method. Currently,the solenoid valve control design scheme has been successfully used in ground engine test equipment. It has a good real-time,security,and time response.

  16. Quantitation of glutamate in the brain by using MR proton spectroscopy at 1.5 T and 3 T; Quantitative Bestimmung von Glutamat im Hirn mithilfe der MR-Protonenspektroskopie bei 1,5 T und 3 T

    Gussew, A.; Rzanny, R.; Reichenbach, J.R. [AG Medizinische Physik, Inst. fuer Diagnostische und Interventionelle Radiologie, Friedrich Schiller Univ. Jena (Germany); Scholle, H.C. [Funktionsbereich Motorik, Pathophysiologie und Biomechanik, Klinik fuer Unfall-, Hand- und Wiederherstellungschirurgie, Friedrich Schiller Univ. Jena (Germany); Kaiser, W.A. [Inst. fuer Diagnostische und Interventionelle Radiologie, Friedrich Schiller Univ Jena (Germany)

    2008-08-15

    Purpose: the influence of different magnetic field strengths on the quantification of glutamate was experimentally investigated by means of in vitro and in vivo {sup 1}H-MR spectroscopic measurements at 1.5 T and 3 T. Materials and methods: in vitro {sup 1}H-MR measurements of aqueous solutions of NAA, glutamate, glutamine and GABA were performed on two clinical MR scanners at 1.5 T and 3 T using a single voxel PRESS sequence (TR/TE = 10000/30 ms). In vitro brain measurements were also performed at both field strengths using a PRESS 2D-{sup 1}H-CSI-sequence (TR/TE = 5000/30 ms) in 6 volunteers. Spectra at 1.5 T and 3 T were compared with respect to the overlap of the single compound spectra and the deviations between estimated and nominally adjusted concentrations. In vivo spectra at both field strengths were compared with respect to SNR{sub Glu}, line width and Cramer-Rao values of the estimated glutamate intensities by using the LCModel. For the thalamus, insular and parietal cortex mean Glu/tCr ratios were estimated and compared between 1.5 T and 3 T as well as with corresponding values in the literature. Results: in general, an improved separation of signal maxima was observed in the in vitro spectra at 3 T. Except for GABA, all in vitro concentrations estimated at 3 T revealed lower deviations from their adjusted nominal concentration compared to 1.5 T: NAA (1.5 T: -5.5%, 3 T: 0.7%), glutamate (1.5 T: -18.1%, 3 T: 12.3%), glutamine (1.5 T: 44.8%, 3 T: 9.2%), GABA (1.5 T: -24.8%, 3 T: 33.8%). The SNR of in vivo spectra at 3 T was nearly doubled compared to 1.5 T. The mean number of voxels with %SD{sub Glu} < 20 was distinctly lower at 1.5 T (53%) than at 3 T (80%). Estimated Glu/tCr ratios for thalamus, insular and parietal cortex lay in the upper range of the literature values. (orig.)

  17. Three dimensional multilayer solenoid microcoils inside silica glass

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Si, Jinhai; Hou, Xun

    2016-01-01

    Three dimensional (3D) solenoid microcoils could generate uniform magnetic field. Multilayer solenoid microcoils are highly pursued for strong magnetic field and high inductance in advanced magnetic microsystems. However, the fabrication of the 3D multilayer solenoid microcoils is still a challenging task. In this paper, 3D multilayer solenoid microcoils with uniform diameters and high aspect ratio were fabricated in silica glass. An alloy (Bi/In/Sn/Pb) with high melting point was chosen as the conductive metal to overcome the limitation of working temperature and improve the electrical property. The inductance of the three layers microcoils was measured, and the value is 77.71 nH at 100 kHz and 17.39 nH at 120 MHz. The quality factor was calculated, and it has a value of 5.02 at 120 MHz. This approach shows an improvement method to achieve complex 3D metal microstructures and electronic components, which could be widely integrated in advanced magnetic microsystems.

  18. Improvements and Performance of the Fermilab Solenoid Test

    Orris, Darryl; et al.

    2016-09-02

    The Solenoid Test Facility at Fermilab was built using a large vacuum vessel for testing of conduction-cooled superconducting solenoid magnets, and was first used to determine the performance of the MICE Coupling Coil [1, 2]. The facility was modified recently to enable testing of solenoid magnets for the Mu2e experiment, which operate at much higher current than the Coupling Coil. One pair of low current conduction-cooled copper and NbTi leads was replaced with two pairs of 10 kA HTS leads cooled by heat exchange with liquid nitrogen and liquid helium. The new design, with additional control and monitoring capability, also provides helium cooling of the superconducting magnet leads by conduction. A high current power supply with energy extraction was added, and several improvements to the quench protection and characterization system were made. Here we present details of these changes and report on performance results from a test of the Mu2e prototype Transport Solenoid (TS) module. Progress on additional improvements in preparation for production TS module testing will be presented.

  19. Approximations for the natural logarithm from solenoid-toroid correspondence

    Semiz, Ibrahim

    2015-01-01

    It seems reasonable that a toroid can be thought of approximately as a solenoid bent into a circle. The correspondence of the inductances of these two objects gives an approximation for the natural logarithm in terms of the average of two numbers. Different ways of averaging give different approximants. They are expressions simpler than Taylor polynomials, and are meaningful over a wider domain.

  20. Teichmüller theory of the punctured solenoid

    Penner, Robert; Sari´c, Dragomir

    2008-01-01

    The punctured solenoid plays the role of an initial object for the category of punctured surfaces with morphisms given by finite covers branched only over the punctures. The (decorated) Teichmüller space of is introduced, studied, and found to be parametrized by certain coordinates on a fixed tri...

  1. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    Virostek, S.P.; Green, M.A.; Trillaud, F.; Zisman, M.S.

    2010-05-16

    The Muon Ionization Cooling Experiment (MICE), an international collaboration sited at Rutherford Appleton Laboratory in the UK, will demonstrate ionization cooling in a section of realistic cooling channel using a muon beam. A five-coil superconducting spectrometer solenoid magnet will provide a 4 tesla uniform field region at each end of the cooling channel. Scintillating fiber trackers within the 400 mm diameter magnet bore tubes measure the emittance of the beam as it enters and exits the cooling channel. Each of the identical 3-meter long magnets incorporates a three-coil spectrometer magnet section and a two-coil section to match the solenoid uniform field into the other magnets of the MICE cooling channel. The cold mass, radiation shield and leads are currently kept cold by means of three two-stage cryocoolers and one single-stage cryocooler. Liquid helium within the cold mass is maintained by means of a re-condensation technique. After incorporating several design changes to improve the magnet cooling and reliability, the fabrication and acceptance testing of the spectrometer solenoids have proceeded. The key features of the spectrometer solenoid magnets, the development of a thermal model, the results of the recently completed tests, and the current status of the project are presented.

  2. Insulating process for HT-7U central solenoid model coils

    2003-01-01

    The HT-7U superconducting Tokamak is a whole superconducting magnetically confined fusion device. The insulating system of its central solenoid coils is critical to its properties. In this paper the forming of the insulating system and the vacuum-pressure-impregnating (VPI) are introduced, and the whole insulating process is verified under the superconducting experiment condition.

  3. Some New Integral Identities for Solenoidal Fields and Applications

    Vladimir I. Semenov

    2014-03-01

    Full Text Available In spaces Rn, n ≥ 2, it has been proved that a solenoidal vector field and its rotor satisfy the series of new integral identities which have covariant form. The interest in them is explained by hydrodynamics problems for an ideal fluid.

  4. ACCELERATORS: Matching by solenoids in space charge dominated LEBTs

    Li, Jin-Hai; Tang, Jing-Yu; Ouyang, Hua-Fu

    2009-10-01

    The betatron matching of a rotationally asymmetric beam in space charge dominated low-energy beam transports (LEBTs) where solenoids are used for the transverse matching has been studied. For better understanding, the coupling elements of a beam matrix are interpreted in special forms that are products of a term defined by the Larmor rotation angle and another by the difference between the beam matrix elements in the two transverse planes. The coupling form originally derived from the rotationally symmetric field in solenoids still holds when taking into account the rotationally asymmetric space charge forces that are due to the unequal emittance in the two transverse planes. It is shown in this paper that when an LEBT mainly comprising solenoids transports a beam having unequal emittance in the two transverse planes and the linear space charge force is taken into account, the initial Twiss parameters can be modified to obtain the minimum and equal emittance at the LEBT exit. The TRACE3D calculations also prove the principle. However, when quadrupoles that are also rotationally asymmetric are involved in between solenoids, the coupling between the two transverse planes becomes more complicated and the emittance increase is usually unavoidable. A matching example using the CSNS (China Spallation Neutron Source) LEBT conditions is also presented.

  5. An electric arc in the magnetic field of a solenoid

    Ungurs, I.A.; Shilova, Ye.I.

    1982-01-01

    A qualitative experiment is described, enabling investigation of the structure of the arc discharge between rod and ring electrodes, and evaluation of the speed of the axial flux created by electromagnetic forces. It is shown that placement of the plasma stream during discharge in the magnetic field of the solenoid provides the possibility of controlling this stream.

  6. Mu2e Transport Solenoid Cold-Mass Alignment Issues

    Lopes, M. [Fermilab; Ambrosio, G. [Fermilab; Badgley, K. [Fermilab; Bradascio, F. [Fermilab; Brandt, J. [Fermilab; Evbota, D. [Fermilab; Hocker, A. [Fermilab; Lamm, M. [Fermilab; Lombardo, V. [Fermilab; Miller, J. [Boston U.; Nicol, T. [Fermilab; Kutschke, R. [Fermilab; Vellidis, C. [Fermilab; Wands, R. [Fermilab; Wenk, E. [Fermilab

    2016-10-01

    The Muon-to-electron conversion experiment (Mu2e) at Fermilab is designed to explore charged lepton flavor violation. It is composed of three large superconducting solenoids: the Production Solenoid (PS), the Transport Solenoid (TS) and the Detector Solenoid (DS). The TS is formed by two magnets: TS upstream (TSu) and downstream (TSd). Each has its own cryostat and power supply. Tolerance sensitivity studies of the position and angular alignment of each coil in this magnet system were performed in the past with the objective to demonstrate that the magnet design meets all the field requirements. The alignment of the cold-masses is critical to maximize the transmission of muons and to avoid possible backgrounds that would reduce the sensitivity of the experiment. Each TS magnet cold-mass can be individually aligned. In this work, we discuss implications of the alignment of the TS cold-masses in terms of the displacement of the magnetic center. Consideration of the practical mechanical limits are also presented.

  7. Complex cystic renal masses: Comparison of cyst complexity and Bosniak classification between 1.5 T and 3 T MRI

    Rosenkrantz, Andrew B., E-mail: Andrew.Rosenkrantz@nyumc.org [Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016 (United States); Wehrli, Natasha E., E-mail: Natasha.Wehrli@nyumc.org [Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016 (United States); Mussi, Thais C., E-mail: thaiscaldara@gmail.com [Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016 (United States); Taneja, Samir S., E-mail: Samir.Taneja@nyumc.org [Department of Urology, Division of Urologic Oncology, NYU Langone Medical Center, 150 East 32nd Street, Suite 200, New York, NY 10016 (United States); Triolo, Michael J., E-mail: Michael.Triolo@nyumc.org [Department of Radiology, NYU Langone Medical Center, 660 First Avenue, New York, NY 10016 (United States)

    2014-03-15

    Purpose: To retrospectively compare perceived complexity and Bosniak cyst classification of cystic renal lesions between 1.5 T and 3 T MRI. Methods: 33 cystic renal lesions in 26 patients that underwent contrast-enhanced MRI at both 1.5 T and 3 T within a 12 month span were included. Two radiologists (R1, R2) independently assessed lesions, unaware of field strength, in terms of number of septations, septal thickening, mural thickening, presence of mural nodule, and Bosniak cyst category. Scores were compared between field strengths for each lesion. Results: R1 observed increases in septal number, septal thickening, mural thickening, and presence of mural nodule at 3 T in 8, 7, 4, and 2 lesions, and at 1.5 T in 3, 3, 2, and 0 lesions, respectively; R2 observed increases in septal number, septal thickening, mural thickening, and presence of mural nodule at 3 T in 3, 4, 3, and 0 lesions, and at 1.5 T in 2, 0, 0, and 0 lesions, respectively. R1 provided higher Bosniak category at 3 T in 9 cases and at 1.5 T in 4 cases; R2 provided higher Bosniak category at 3 T in 4 cases and at 1.5 T in 0 cases. Higher scores at 3 T than 1.5 T were associated with differences in advised clinical management in 7/9 cases for R1 and 4/4 cases for R2. Conclusion: There was an overall tendency for both readers to upgrade cyst complexity and Bosniak cyst category at 3 T than 1.5 T, which impacted advised management. Thus, we suggest that serial MRI evaluation of cystic renal lesions be performed at constant field strength.

  8. Basic Study of Susceptibility-Weighted Imaging at 1.5T

    Sasai,Nobuya

    2008-06-01

    Full Text Available With the aim of sequence optimization in susceptibility-weighted imaging (SWI, 2 image acquisition parameters (slice thickness and matrix size and 2 image processing conditions (number of slices per minimum intensity projection (MIP and Sliding Window were investigated using a 1.5-T magnetic resonance imaging (MRI system. The subjects were 12 healthy volunteers and the target region for scanning was the whole brain. Informed consent was obtained from all subjects. First, susceptibility-weighted images were acquired with various slice thicknesses from 1mm to 5mm and various matrix sizes from 256x256 to 512x512, and the images were assessed in terms of the contrast-to-noise ratio (CNR and were also visually evaluated by three radiologists. Then, the number of slices per MIP and the usefulness of the Sliding Window were investigated. In the study of the optimal slice thickness and matrix size, the results of visual evaluation suggested that a slice thickness of 3mm and a matrix size of 448x448 are optimal, while the results of evaluation based on CNR were not significant. As regards the image processing conditions, the results suggested that the number of slices per MIP should be set to a minimum value of 2 and that the use of Sliding Window is effective. The present study provides useful reference data for optimizing SWI sequences.

  9. Effects of 1.5 T magnetic fields on cell cultures of macrophages and amniocytes

    Santos, C. [IBILI-Biomedical Institute for Research on Light and Image, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas 3000-354 Coimbra (Portugal); Pinto, M. [Laboratorio Citogenetica, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas 3000-354 Coimbra (Portugal); Caramelo, F. [IBILI-Biomedical Institute for Research on Light and Image, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas 3000-354 Coimbra (Portugal); Pinto, A. [Servico de Imagiologia, Hospitais da Universidade de Coimbra, Av. Bissaya Barreto, 3000 Coimbra (Portugal); Pires, D.; Fernandes, H.; Duarte, I; Amaro, J.; Caldas, J.; Medeiros, J.; Inacio, R.; Lavrador, R.; Almeida, T. [Faculty of Science and Technology, University of Coimbra, Rua Larga da Universidade, 3004-516 Coimbra (Portugal); Caseiro-Alves, F. [Servico de Imagiologia, Hospitais da Universidade de Coimbra, Av. Bissaya Barreto, 3000 Coimbra (Portugal); Carreira, I [Laboratorio Citogenetica, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas 3000-354 Coimbra (Portugal); Botelho, M.F. [IBILI-Biomedical Institute for Research on Light and Image, Faculty of Medicine, University of Coimbra, Azinhaga de Santa Comba, Celas 3000-354 Coimbra (Portugal)

    2009-05-15

    Magnetic resonance is frequently used to obtain medical images for diagnosis. To perform these exams high magnetic fields are applied, implying at least circa 10000 times the value of the Earth basal field (0.00003 to 0.00007 T). In our experimental study we used two different adherent types of cells (rat peritoneal macrophages and human amniocytes), cultured in standard conditions (37 C, 5% CO2) with adequate media in 6 wells plates. Three groups for each type of cell were established: control, head and body coil, being the irradiation performed with a MR System MAGNETON 1.5 T (University Hospital of Coimbra). Macrophages' cytotoxicity and viability were tested with the MTT1 assay 0, 12, 36, 60 and 84 hours post-irradiation, amniocytes viability and chromosome alteration were studied 3, 13, 37, 109, 205 hours post-irradiation. Irradiated macrophages presented slightly less viability and adhesion features compared to control, although no differences between the head and body coil were found. Amniocytes showed no significant differences amongst them. (author)

  10. Transverse emittance measurement at REGAE via a solenoid scan

    Hachmann, Max

    2012-12-15

    The linear accelerator REGAE at DESY produces short and low charged electron bunches, on the one hand to resolve the excitation transitions of atoms temporally by pump probe electron diffraction experiments and on the other hand to investigate principal mechanisms of laser plasma acceleration. For both cases a high quality electron beam is required. A quantity to rate the beam quality is the beam emittance. In the course of this thesis transverse emittance measurements by a solenoid scan could be realized and beyond that an improved theoretical description of a solenoid was successful. The foundation of emittance measurements are constituted by theoretical models which describe the envelope of a beam. Two different models were derived. The first is an often used model to determine the transverse beam emittance without considering space charge effects. More interesting and challenging was the development of an envelope model taking space charge effects into account. It is introduced and cross checked with measurements and simulations.

  11. Integration of RFQ beam coolers and solenoidal magnetic fields

    Cavenago, M.; Romé, M.; Maggiore, M.; Porcellato, A. M.; Maero, G.; Chiurlotto, F.; Comunian, M.; Galatà, A.; Cavaliere, F.

    2016-02-01

    Electromagnetic traps are a flexible and powerful method of controlling particle beams, possibly of exotic nuclei, with cooling (of energy spread and transverse oscillations) provided by collisions with light gases as in the Radio Frequency Quadrupole Cooler (RFQC). A RFQC prototype can be placed inside the existing Eltrap solenoid, capable of providing a magnetic flux density component Bz up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by Bz and the rf voltage Vrf (up to 1 kV at few MHz). Transport is provided by a static electric field Ez (order of 100 V/m), while gas collisions (say He at 1 Pa, to be maintained by differential pumping) provide cooling or heating depending on Vrf. The beamline design and the major parameters Vrf, Bz (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

  12. High luminosity interaction region design for collisions with detector solenoid

    Milardi, C; Raimondi, P; Sensolini, G; Sgamma, F

    2010-01-01

    An innovatory interaction region has been recently conceived and realized on the Frascati DA{\\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted until now to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirements

  13. Cosmic Solenoids Minimal Cross-Section and Generalized Flux Quantization

    Davidson, A; Davidson, Aharon; Karasik, David

    1999-01-01

    A self-consistent general relativistic configuration describing a finite cross-section magnetic flux tube is constructed. The cosmic solenoid is modeled by an elastic superconductive surface which separates the Melvin core from the surrounding flat conic structure. We show that a given amount $\\Phi$ of magnetic flux cannot be confined within a cosmic solenoid of circumferential radius smaller than $\\frac{\\sqrt{3G}}{2\\pi c^2}\\Phi$ without creating a conic singularity. Gauss-Codazzi matching conditions are derived by means of a self-consistent action. The source term, representing the surface currents, is sandwiched between internal and external gravitational surface terms. Surface superconductivity is realized by means of a Higgs scalar minimally coupled to projective electromagnetism. Trading the 'magnetic' London phase for a dual 'electric' surface vector potential, the generalized quantization condition reads: $e/{hc} \\Phi + 1/e Q=n$ with $Q$ denoting some dual 'electric' charge, thereby allowing for a non-...

  14. Design of High Field Solenoids made of High Temperature Superconductors

    Bartalesi, Antonio; /Pisa U.

    2010-12-01

    This thesis starts from the analytical mechanical analysis of a superconducting solenoid, loaded by self generated Lorentz forces. Also, a finite element model is proposed and verified with the analytical results. To study the anisotropic behavior of a coil made by layers of superconductor and insulation, a finite element meso-mechanic model is proposed and designed. The resulting material properties are then used in the main solenoid analysis. In parallel, design work is performed as well: an existing Insert Test Facility (ITF) is adapted and structurally verified to support a coil made of YBa{sub 2}Cu{sub 3}O{sub 7}, a High Temperature Superconductor (HTS). Finally, a technological winding process was proposed and the required tooling is designed.

  15. Results of the ATLAS solenoid magnetic field map

    Aleksa, M; Chevalier, L; Giudici, P A; Hart, J C; Kehrli, A; Losasso, M; Miyagawa, P S; Pons, X; Sandaker, H; Snow, S W

    2008-01-01

    ATLAS is a general-purpose detector designed to explore a wide range of particle physics topics at the Large Hadron Collider. A crucial component to the success of ATLAS will be a precise knowledge of the magnetic field produced by the ATLAS solenoid. To achieve this, a special field mapping machine was built and deployed to measure the solenoid magnetic field. This paper describes the mapping machine, the field mapping campaign, and the subsequent analysis of the field map data. After a series of small corrections, some taken from surveys and some derived from the data itself, were applied to the recorded data, the corrected data were fitted with a function obeying Maxwell's equations. The resulting field residuals had an rms of less than 0.5 mT, and the systematic error on the measurement of track sagitta due to the field uncetainty was estimated to range fom 2-12 × 10-4, depending on the tack rapidity.

  16. Analytical Study of Stress State in HTS Solenoids

    Barzi, E.; Terzini, E.; /Fermilab

    2009-01-01

    A main challenge for high field solenoids made of in High Temperature Superconductor (HTS) is the large stress developed in the conductor. This is especially constraining for BSCCO, a brittle and strain sensitive ceramic material. To find parametric correlations useful in magnet design, analytical models can be used. A simple model is herein proposed to obtain the radial, azimuthal and axial stresses in a solenoid as a function of size, i.e. self-field, and of the engineering current density for a number of different constraint hypotheses. The analytical model was verified against finite element modeling (FEM) using the same hypotheses of infinite rigidity of the constraints and room temperature properties. FEM was used to separately evaluate the effect of thermal contractions at 4.2 K for BSCCO and YBCO coils. Even though the analytical model allows for a finite stiffness of the constraints, it was run using infinite stiffness. For this reason, FEM was again used to determine how much stresses change when considering an outer stainless steel skin with finite rigidity for both BSCCO and YBCO coils. For a better understanding of the actual loads that high field solenoids made of HTS will be subject to, we have started some analytical studies of stress state in solenoids for a number of constraint hypotheses. This will hopefully show what can be achieved with the present conductor in terms of self-field. The magnetic field (B) exerts a force F = B x J per unit volume. In superconducting magnets, where the field and current density (J) are both high, this force can be very large, and it is therefore important to calculate the stresses in the coil.

  17. HIE-ISOLDE CRYO-MODULE Assembly - Superconducting Solenoid

    Leclercq, Yann

    2016-01-01

    Assembly of the cryo-module components in SM18 cleanroom. The superconducting solenoid (housed inside its helium vessel) is cleaned, prepared then installed on the supporting frame of the cryo-module and connected to the helium tank, prior to the assembly of the RF cavities on the structure. The completed first 2 cryo-modules installed inside the HIE-ISOLDE-LINAC ready for beam operation is also shown.

  18. Design and characterization of permanent magnetic solenoids for REGAE

    Hachmann, M., E-mail: max.hachmann@desy.de [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany); Flöttmann, K. [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany); Gehrke, T. [Deutsches Krebsforschungszentrum DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Mayet, F. [Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, 22607 Hamburg (Germany)

    2016-09-01

    REGAE is a small electron linear accelerator at DESY. In order to focus short and low charged electron bunches down to a few μm permanent magnetic solenoids were designed, assembled and field measurements were done. Due to a shortage of space close to the operation area an in-vacuum solution has been chosen. Furthermore a two-ring design made of wedges has been preferred in terms of beam dynamic issues. To keep the field quality of a piecewise built magnet still high a sorting algorithm for the wedge arrangement including a simple magnetic field model has been developed and used for the construction of the magnets. The magnetic field of these solenoids has been measured with high precision and compared to simulations. - Highlights: • presenting a two-ring radially magnetized permanent magnetic solenoid design. • development of a analytical field description and field quality factor. • development of a sorting algorithm for permanent magnetic pieces to form a magnet. • performing a high-precision field measurement of a high gradient field.

  19. EU Directive 2004/40: field measurements of a 1.5 T clinical MR scanner.

    Riches, S F; Collins, D J; Scuffham, J W; Leach, M O

    2007-06-01

    The European Union (EU) Physical Agents (EMF) Directive [1] must be incorporated into UK law in 2008. The directive, which applies to employees working in MRI, sets legal exposure limits for two of the three types of EMF exposure employed in MRI; time-varying gradient fields and radiofrequency (RF) fields. Limits on the static field are currently not included but may be added at a later date. Conservative action values have been set for all three types of exposure including the static field. The absolute exposure limits will exclude staff from the scanner bore and adjacent areas during scanning, impacting on many clinical activities such as anaesthetic monitoring during sedated scans, paediatric scanning and interventional MRI. When the legislation comes into force, NHS Trusts, scanner companies and academic institutions will be required to show compliance with the law. We present results of initial measurements performed on a 1.5 T clinical MRI scanner. For the static field, the proposed action value is exceeded at 40 cm from the scanner bore and would be exceeded when positioning a patient for scanning. For the RF field, the action values were only exceeded within the bore at distances of 40 cm from the scanner ends during a very RF intensive sequence; MRI employees are unlikely to be in the bore during an acquisition. For the time-varying gradient fields the action values were exceeded 52 cm out from the mouth of the bore during two clinical sequences, and estimated current densities show the exposure limit to be exceeded at 40 cm for frequencies above 333 Hz. Limiting employees to distances greater than these from the scanner during acquisition will have a severe impact on the future use and development of MRI.

  20. MR imaging of the chest: A practical approach at 1.5 T

    Puderbach, M. [DKFZ, Department of Radiology (E010), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)], E-mail: m.puderbach@dkfz.de; Hintze, C. [DKFZ, Department of Radiology (E010), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Ley, S. [DKFZ, Department of Radiology (E010), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); University Heidelberg, Department of Pediatric Radiology, Im Neuenheimer Feld 153, 69120 Heidelberg (Germany); Eichinger, M.; Kauczor, H.-U. [DKFZ, Department of Radiology (E010), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Biederer, J. [University Hospital Schleswig-Holstein, Campus Kiel, Department of Diagnostic Radiology, Arnold-Heller-Str. 9, 24105 Kiel (Germany)

    2007-12-15

    Magnetic resonance imaging (MRI) is capable of imaging infiltrative lung diseases as well as solid lung pathologies with high sensitivity. The broad use of lung MRI was limited by the long study time as well as its sensitivity to motion and susceptibility artifacts. These disadvantages were overcome by the utilisation of new techniques such as parallel imaging. This article aims to propose a standard MR imaging protocol at 1.5 T and presents a spectrum of indications. The standard protocol comprises non-contrast-enhanced sequences. Following a GRE localizer (2D-FLASH), a coronal T2w single-shot half-Fourier TSE (HASTE) sequence with a high sensitivity for infiltrates and a transversal T1w 3D-GRE (VIBE) sequence with a high sensitivity for small lesions are acquired in a single breath hold. Afterwards, a coronal steady-state free precession sequence (TrueFISP) in free breathing is obtained. This sequence has a high sensitivity for central pulmonary embolism. Distinct cardiac dysfunctions as well as an impairment of the breathing mechanism are visible. The last step of the basic protocol is a transversal T2w-STIR (T2-TIRM) in a multi-breath holds technique to visualize enlarged lymph nodes as well as skeletal lesions. The in-room time is approximately 15 min. The extended protocol comprises contrast-enhanced sequences (3D-GRE sequence (VIBE) after contrast media; about five additional minutes). Indications are tumorous lesions, unclear (malignant) pleural effusions and inflammatory diseases (vaskulitis). A perfusion analysis can be achieved using a 3D-GRE in shared echo-technique (TREAT) with a high temporal resolution. This protocol can be completed using a MR-angiography (3D-FLASH) with high spatial resolution. The in-room time for the complete protocol is approximately 30 min.

  1. Post-mortem 1.5T MR quantification of regular anatomical brain structures.

    Zech, Wolf-Dieter; Hottinger, Anna-Lena; Schwendener, Nicole; Schuster, Frederick; Persson, Anders; Warntjes, Marcel J; Jackowski, Christian

    2016-07-01

    Recently, post-mortem MR quantification has been introduced to the field of post-mortem magnetic resonance imaging. By usage of a particular MR quantification sequence, T1 and T2 relaxation times and proton density (PD) of tissues and organs can be quantified simultaneously. The aim of the present basic research study was to assess the quantitative T1, T2, and PD values of regular anatomical brain structures for a 1.5T application and to correlate the assessed values with corpse temperatures. In a prospective study, 30 forensic cases were MR-scanned with a quantification sequence prior to autopsy. Body temperature was assessed during MR scans. In synthetically calculated T1, T2, and PD-weighted images, quantitative T1, T2 (both in ms) and PD (in %) values of anatomical structures of cerebrum (Group 1: frontal gray matter, frontal white matter, thalamus, internal capsule, caudate nucleus, putamen, and globus pallidus) and brainstem/cerebellum (Group 2: cerebral crus, substantia nigra, red nucleus, pons, cerebellar hemisphere, and superior cerebellar peduncle) were assessed. The investigated brain structures of cerebrum and brainstem/cerebellum could be characterized and differentiated based on a combination of their quantitative T1, T2, and PD values. MANOVA testing verified significant differences between the investigated anatomical brain structures among each other in Group 1 and Group 2 based on their quantitative values. Temperature dependence was observed mainly for T1 values, which were slightly increasing with rising temperature in the investigated brain structures in both groups. The results provide a base for future computer-aided diagnosis of brain pathologies and lesions in post-mortem magnetic resonance imaging.

  2. Controlling backstreaming ions from X-ray converter targets with time varying final focusing solenoidal lens and beam energy variation

    Caporaso, G J; Chen, Yu-Jiuan; Paul, A

    1998-08-20

    Backstreaming ions emitted from an x-ray converter hit by a tightly focused intense electron beam can form an ion focusing channel and over-focus the electron beam. As the ions move upstream in time, the net focusing strength increases. The final beam spot size on the target would then change in time and typically be larger than intended. We have developed a model to estimate the backstreaming ions' neutralization factor in a potential sheath near the target surface and away from the sheath. Performance of high resolution x-ray radiography facilities requires high current electron beams to be focused to a millimeter spot size on an x-ray converter through out the entire current pulse. We have studied the possibility of maintaining a constant final spot size for the entire pulse by using either a time varying final focusing solenoid field or beam energy variation to compensate the time varying ion focusing effects

  3. MR imaging of the brachial plexus: comparison between 1.5-T and 3-T MR imaging: preliminary experience

    Tagliafico, Alberto; Neumaier, Carlo Emanuele; Calabrese, Massimo [National Institute for Cancer Research, Department of Radiology, Genova (Italy); Succio, Giulia; Serafini, Giovanni; Ghidara, Matteo [Santa Corona Hospital, Radiology Department, Savona (Italy); Martinoli, Carlo [Universita di Genova, Radiology Department, Genova (Italy)

    2011-06-15

    To compare 1.5-T and 3-T magnetic resonance (MR) imaging of the brachial plexus. Institutional review board approval and informed consent were obtained from 30 healthy volunteers and 30 consecutive patients with brachial plexus disturbances. MR was prospectively performed with comparable sequence parameters and coils with a 1.5-T and a 3-T system. Imaging protocols at both field strengths included T1-weighted turbo spin-echo (tSE) sequences and T2-weighed turbo spin-echo (tSE) sequences with fat saturation. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between muscle and nerve were calculated for both field strengths. The visibility of brachial plexus nerve at various anatomic levels (roots, interscalene area, costoclavicular space, and axillary level) was analyzed with a four-point grading scale by two radiologists. MR imaging diagnoses and pathological findings were also compared qualitatively. SNR and CNRs were significantly higher on 3-T MR images than on 1.5-T MR images (Friedman test) for all sequences. Nerve visibility was significantly better on 3-T MR images than on 1.5-T MR images (paired sign test). Pathological findings (n = 30/30) were seen equally well with both field strengths. MR imaging diagnoses did not differ for the 1.5- and 3-T protocols. High-quality MR images of the brachial plexus can be obtained with 3-T MR imaging by using sequences similar to those used at 1.5-T MR imaging. In patients and healthy volunteers, the visibility of nerve trunks and cords at 3-T MR imaging appears to be superior to that at 1.5-T MR imaging. (orig.)

  4. Design of a Solenoid Actuator with a Magnetic Plunger for Miniaturized Segment Robots

    Chang-Woo Song

    2015-09-01

    Full Text Available We develop a solenoid actuator with a ferromagnetic plunger to generate both rectilinear and turning motions of a multi-segmented robot. Each segment of the miniaturized robot is actuated by a pair of solenoids, and in-phase and out-of-phase actuations of the solenoid pair cause the linear and turning motions. The theoretical analysis on the actuation force by the solenoid with the magnetic plunger is implemented based on the Biot-Savart law. The optimal design parameters of the solenoid are determined to actuate a segmented body. We manufacture the miniaturized robot consisting of two segments and a pair of solenoids. Experiments are performed to measure the linear and angular displacements of the two-segmented robot for various frictional conditions.

  5. Optimization of brain MRA withcontrast injection in 1.5 T field

    H. Qenaati

    2006-01-01

    Full Text Available Background and purpose: Selection of suitable parameters for brain MRA requires accurate measures, because the image quality depends on the location of arteries, veins and also the velocity differences of blood, taking into account the low blood flow in small veins and arteries, use of paramagnetic contrast media is recommended. Hence, in present study, we investigated the imaging optimization of brain vessels using contrast media in 1.5 T field.Materials and Methods: For image optimization blood T1 was estimated after the injection of 0.1mmol/kg of Gd-DTPA and the relative blood signals were measured at T1=300, 600, 900 and 1200ms using TR=20ms and TE=7ms parameters. Ernest angle and relative signal increased as the T1 decreased. MRA was obtained in three groups, each including five volunteer patients using parameters TR=20ms, TE=7ms and flip angle 10, 20 & 30 degrees in two series without and during contrast injection.Signals of carotid, M.C.A and thorcolar herofili and SD in air were measured and it was shown that in 20 degrees flip angle, C/N was maximum.At the last stage, three series of MRA, without, during c.i and 15 minutes after c.i where obtained in 20 volunteer patients using parameters TR=20ms, TE=7ms and flip angle 20 degrees and calculated C/N .Results: After statistical analysis the highest C/N was observed during c.i MRA. Paired t-student test was performed to compare the differences between the C/N ratios. For clinical purposes one vein and two arterles were graded in 5 definite levels.Conclusion: Results indicated an important effect of paramagnetic contrast media on better observing of small arteries and vein. The best quality was taken during c.i, but in some arteries contrast media did not improve the quality of MRA.

  6. A solenoid-based active hydraulic engine mount: modelling, analysis, and verification

    Hosseini, Ali

    2010-01-01

    The focus of this thesis is on the design, modelling, identification, simulation, and experimental verification of a low-cost solenoid-based active hydraulic engine mount. To build an active engine mount, a commercial On-Off solenoid is modified to be used as an actuator and it is embedded inside a hydraulic engine mount. The hydraulic engine mount is modelled and tested, solenoid actuator is modelled and identified, and finally the models were integrated to obtain the analytical model of the...

  7. Solenoidal Fields for Ion Beam Transport and Focusing

    Lee, Edward P.; Leitner, Matthaeus

    2007-11-01

    In this report we calculate time-independent fields of solenoidal magnets that are suitable for ion beam transport and focusing. There are many excellent Electricity and Magnetism textbooks that present the formalism for magnetic field calculations and apply it to simple geometries [1-1], but they do not include enough relevant detail to be used for designing a charged particle transport system. This requires accurate estimates of fringe field aberrations, misaligned and tilted fields, peak fields in wire coils and iron, external fields, and more. Specialized books on magnet design, technology, and numerical computations [1-2] provide such information, and some of that is presented here. The AIP Conference Proceedings of the US Particle Accelerator Schools [1-3] contain extensive discussions of design and technology of magnets for ion beams - except for solenoids. This lack may be due to the fact that solenoids have been used primarily to transport and focus particles of relatively low momenta, e.g. electrons of less than 50 MeV and protons or H- of less than 1.0 MeV, although this situation may be changing with the commercial availability of superconducting solenoids with up to 20T bore field [1-4]. Internal reports from federal laboratories and industry treat solenoid design in detail for specific applications. The present report is intended to be a resource for the design of ion beam drivers for Inertial Fusion Energy [1-5] and Warm Dense Matter experiments [1-6], although it should also be useful for a broader range of applications. The field produced by specified currents and material magnetization can always be evaluated by solving Maxwell's equations numerically, but it is also desirable to have reasonably accurate, simple formulas for conceptual system design and fast-running beam dynamics codes, as well as for general understanding. Most of this report is devoted to such formulas, but an introduction to the Tosca{copyright} code [1-7] and some

  8. Design of solenoid detecting platform based on DDS technology%基于DDS技术的电磁阀检测平台的设计

    丁磊; 周凤星

    2011-01-01

    为了测试电磁阀在各种工作状态下(即在不同的输入脉冲供电的情况下)的性能,研制了一种模拟电磁阀工作状态的PWM脉冲电源.该电源依靠CPLD构成数字PWM发生器,由单片机控制,具有短路保护和浪涌保护功能.系统软件部分以模块化的方式实现,能够连续地输出不同的PWM脉冲.该电源目前已成功应用到电磁阀的生产企业,为企业创造了显著的经济效益,为我国电磁阀的出口做出了贡献.%To test the performance of solenoid valve in a variety of working conditions (I.e., under different inputpulses to supply power) ,a PWM pulse power supply which can simulate the working state of solenoid valve was developed. This power supply which includes digital PWM generator constituted by CPLD, is controlled by single-chip microcomputer and it is provided with short-circuit protection and surge protection. The software system which is implemented in a modular form part , is able to output different continuous PWM pulses.The power supply has been successfully applied to the motorcar solenoid valvea manufacturers,it not only has creating significant economic benefits for enterprises,but also has contributing to the export of our solenoid valve.

  9. Evaluation of intracranial aneurysms with 7 T versus 1.5 T time-of-flight MR angiography. Initial experience

    Moenninghoff, C.; Maderwald, S.; Theysohn, J.M.; Kraff, O.; Ladd, S.C.; Ladd, M.E.; Forsting, M.; Quick, H.H.; Wanke, I. [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Duisburg-Essen Univ. (Germany). Erwin-L.-Hahn Inst. fuer Magnetresonanz

    2009-01-15

    Purpose: The purpose of this study was to compare the depiction of intracranial aneurysms by 3D time-of-flight (TOF) magnetic resonance angiography (MRA) at 7 Tesla (T) with the clinical standard TOF MRA at 1.5 T and with digital subtraction angiography (DSA). Materials and Methods: 7 T and 1.5 T TOF MRA images optimized for both field strengths were compared in ten patients with an unruptured intracranial aneurysm. Two blinded neuroradiologists independently rated the image quality of the dome, the neck, and the vessel of origin of all aneurysms in MRA source and maximum intensity projection (MIP) images. DSA was obtained in all subjects and served as reference standard. The mean values of image quality were compared by Wilcoxon signed rank test. In all patients the number and location of the aneurysms was confirmed by DSA. Results: Both readers identified twelve aneurysms in ten patients in 7 T, 1.5 T TOF MRA and DSA. The image quality of the aneurysm dome was rated higher in 8 of 12 aneurysms and the image quality of the aneurysm neck was superior in 9 of 12 aneurysms at 7 T TOF MRA compared to 1.5 T TOF MRA. The depiction of the parent vessel was graded almost equally by both readers. Conclusion: Our initial results indicate that image quality of intracranial aneurysms may benefit from the increased spatial resolution of 7 T TOF MRA compared with 1.5 T TOF MRA. Tailored scan protocols and optimized radiofrequency head coils are needed to further improve the image quality of 7 T TOF MRA. (orig.)

  10. Heavy ion physics at LHC with the Compact Muon Solenoid

    Bedjidian, M.; Contardo, D.; Haroutunian, R. [Universite Claude Bernard Lyon 1, Villeurbanne (France)] [and others

    1995-07-15

    The Compact Muon Solenoid (CMS), is one of the two detectors proposed to achieve the primary goal of the LHC: the discovery of the Higgs boson(s). For this purpose, the detector is optimized for the precise measurement of muons, photons, electrons and jets. It is a clear motivation to investigate its ability to measure the hard processes probing the formation of a Quark Gluon Plasma (QGP) in ion collisions. It is the case of the heavy quark bound states, long predicted to be suppressed in a QGP. In CMS they can be detected, via their muonic decay according to the principle adopted for the p-p physics.

  11. MR diagnosis of bone metastases at 1.5 T and 3 T. Can STIR imaging be omitted?

    Ohlmann-Knafo, S.; Tarnoki, A.D.; Tarnoki, D.L.; Pickuth, D. [Caritasklinikum Saarbruecken St. Theresia (Germany). Dept. of Diagnostic and Interventional Radiology

    2015-10-15

    To date, no prospective comparative study of the diagnostic value of STIR versus T1-weighted (T1w) sequences at both 1.5 T and 3 T has been performed with special focus on the detectability of bone metastases. 212 oncological patients had a whole-body MRI at 1.5 T and/or at 3 T. The standard protocol comprised STIR and T1w sequences. All patients who showed typical signs of bone metastases were included in the study. Evaluation of the images was performed by the calculation of the number of metastases by three independent readers and by visual assessment on a 4-point scale. 86 patients fulfilled the inclusion criteria. The total number of metastases was significantly higher on T1w than on STIR images at both field strengths (p < 0.05). T1w revealed a sensitivity of 99.72 % (3 T) and 100.00 % (1.5 T) versus STIR with 70.99 % (3 T) and 79.34 % (1.5 T). In 53 % (38/72) of all patients, STIR detected fewer bone metastases in comparison with T1w at 3 T. At 1.5 T, STIR showed inferior results in 37.5 % (18/48) of all patients. Qualitative analysis indicated a significantly better lesion conspicuity, lesion delineation and an improved image quality on T1w compared to STIR imaging at both field strengths (p < 0.05) with similar results for T1w at 1.5 T and 3 T, but inferior results for STIR especially at 3 T. The whole-body MRI protocol for the detection of bone metastases could safely be limited to the T1w sequence in adults, especially at 3 T. There is no need for an additional STIR sequence. These initial results will have a major impact on the department's workflow if confirmed by larger studies as they will help reduce examination time and therefore save financial resources.

  12. Application of quantitative MRI for brain tissue segmentation at 1.5 T and 3.0 T field strengths.

    Janne West

    Full Text Available BACKGROUND: Brain tissue segmentation of white matter (WM, grey matter (GM, and cerebrospinal fluid (CSF are important in neuroradiological applications. Quantitative Mri (qMRI allows segmentation based on physical tissue properties, and the dependencies on MR scanner settings are removed. Brain tissue groups into clusters in the three dimensional space formed by the qMRI parameters R1, R2 and PD, and partial volume voxels are intermediate in this space. The qMRI parameters, however, depend on the main magnetic field strength. Therefore, longitudinal studies can be seriously limited by system upgrades. The aim of this work was to apply one recently described brain tissue segmentation method, based on qMRI, at both 1.5 T and 3.0 T field strengths, and to investigate similarities and differences. METHODS: In vivo qMRI measurements were performed on 10 healthy subjects using both 1.5 T and 3.0 T MR scanners. The brain tissue segmentation method was applied for both 1.5 T and 3.0 T and volumes of WM, GM, CSF and brain parenchymal fraction (BPF were calculated on both field strengths. Repeatability was calculated for each scanner and a General Linear Model was used to examine the effect of field strength. Voxel-wise t-tests were also performed to evaluate regional differences. RESULTS: Statistically significant differences were found between 1.5 T and 3.0 T for WM, GM, CSF and BPF (p<0.001. Analyses of main effects showed that WM was underestimated, while GM and CSF were overestimated on 1.5 T compared to 3.0 T. The mean differences between 1.5 T and 3.0 T were -66 mL WM, 40 mL GM, 29 mL CSF and -1.99% BPF. Voxel-wise t-tests revealed regional differences of WM and GM in deep brain structures, cerebellum and brain stem. CONCLUSIONS: Most of the brain was identically classified at the two field strengths, although some regional differences were observed.

  13. Geometric accuracy in three-dimensional coordinates of Leksell stereotactic skull frame with wide-bore 1.5-T MRI compared with conventional 1.5-T MRI.

    Nakazawa, Hisato; Komori, Masataka; Shibamoto, Yuta; Takikawa, Yukinori; Mori, Yoshimasa; Tsugawa, Takahiko

    2014-10-01

    The use of 1.5-tesla (T) magnetic resonance (MR) imaging with a wide and simultaneously short bore enhances patient comfort compared with traditional 1.5-T MR imaging and is becoming increasingly available in stereotactic radiosurgery treatment planning. However, the geometric accuracy seems unavoidably worse in wide-bore MR imaging than in conventional MR imaging. We assessed the geometric distortion of the stereotactic image attached on a Leksell skull frame in conventional and wide-bore 1.5-T MR imaging. Two kinds of acrylic phantoms were placed on the skull frame and were scanned using computed tomography (CT) and conventional and wide-bore 1.5-T MR imaging. The three-dimensional coordinates on both MR imaging were compared with those on CT. Deviations of measured coordinates at selected points (x = 50, 100, 150 mm; y = 50, 100, 150 mm) were indicated on different axial planes (z = 50, 75, 100, 125, 150 mm). The differences of coordinates were less than 1.0 mm in the entire treatable area for conventional MR imaging. With the large bore system, the differences of the coordinates were less than 1.0 mm around the center but substantially exceeded 1.0 mm in the peripheral regions. Further study is needed to increase the geometric accuracy of wide-bore MR imaging for stereotactic radiosurgery treatment planning.

  14. Qualification of the Joints for the ITER Central Solenoid

    Martovetsky, N; Berryhill, A; Kenney, S

    2011-09-01

    The ITER Central Solenoid has 36 interpancake joints, 12 bus joints, and 12 feeder joints in the magnet. The joints are required to have resistance below 4 nOhm at 45 kA at 4.5 K. The US ITER Project Office developed two different types of interpancake joints with some variations in details in order to find a better design, qualify the joints, and establish a fabrication process. We built and tested four samples of the sintered joints and two samples with butt-bonded joints (a total of eight joints). Both designs met the specifications. Results of the joint development, test results, and selection of the baseline design are presented and discussed in the paper. The ITER Central Solenoid (CS) consists of six modules. Each module is composed of six wound hexapancakes and one quadrapancake. The multipancakes are connected electrically and hydraulically by in-line interpancake joints. The joints are located at the outside diameter (OD) of the module. Cable in conduit conductor (CICC) high-current joints are critical elements in the CICC magnets. In addition to low resistivity, the CS joints must fit a space envelope equivalent to the regular conductor cross section and must have low hydraulic impedance and enough structural strength to withstand the hoop and compressive forces during operation, including cycling. This paper is the continuation of the work reported on the intermodule joints.

  15. The superconducting strand for the CMS solenoid conductor

    Curé, B; Campi, D; Goodrich, L F; Horváth, I L; Kircher, F; Liikamaa, R; Seppälä, J; Smith, R P; Teuho, J; Vieillard, L

    2002-01-01

    The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. Approximately 2000 km of superconducting strand is under procurement for the conductor of the CMS superconducting solenoid. Each strand length is required to be an integral multiple of 2.75 km. The strand is composed of copper- stabilized multifilamentary Nb-Ti with Nb barrier. Individual strands are identified by distinctive patterns of Nb-Ti filaments selected during stacking of the monofilaments. The statistics of piece length, measurements of I/sub c/, n-value, copper RRR, (Cu+Nb)/Nb-Ti ratio, as well as the results of independent cross checks of these quantities, are presented. A study was performed on the CMS strands to investigate the critical current degradation due to various heat treatments. The degradation versus annealing temperature and duration are reported. (4 refs).

  16. Cellular Imaging at 1.5 T: Detecting Cells in Neuroinflammation using Active Labeling with Superparamagnetic Iron Oxide

    Ayman J. Oweida

    2004-04-01

    Full Text Available The ability to visualize cell infiltration in experimental autoimmune encephalomyelitis (EAE, a well-known animal model for multiple sclerosis in humans, was investigated using a clinical 1.5-T magnetic resonance imaging (MRI scanner, a custom-built, high-strength gradient coil insert, a 3-D fast imaging employing steady-state acquisition (FIESTA imaging sequence and a superparamagnetic iron oxide (SPIO contrast agent. An “active labeling” approach was used with SPIO administered intravenously during inflammation in EAE. Our results show that small, discrete regions of signal void corresponding to iron accumulation in EAE brain can be detected using FIESTA at 1.5 T. This work provides early evidence that cellular abnormalities that are the basis of diseases can be probed using cellular MRI and supports our earlier work which indicates that tracking of iron-labeled cells will be possible using clinical MR scanners.

  17. Method and apparatus for monitoring armature position in direct-current solenoids

    Moyers, J.C.; Haynes, H.D.

    1996-12-10

    A method for determining the position of an armature of a dc-powered solenoid is disclosed. Electrical circuitry is provided to introduce a small alternating current flow through the coil. As a result, the impedance and resistance of the solenoid coil can be measured to provide information indicative of the armature`s position. 5 figs.

  18. Using Experiment and Computer Modeling to Determine the Off-Axis Magnetic Field of a Solenoid

    Lietor-Santos, Juan Jose

    2014-01-01

    The study of the ideal solenoid is a common topic among introductory-based physics textbooks and a typical current arrangement in laboratory hands-on experiences where the magnetic field inside a solenoid is determined at different currents and at different distances from its center using a magnetic probe. It additionally provides a very simple…

  19. Performance of a proximity cryogenic system for the ATLAS central solenoid magnet

    Doi, Y; Makida, Y; Kondo, Y; Kawai, M; Aoki, K; Haruyama, T; Kondo, T; Mizumaki, S; Wachi, Y; Mine, S; Haug, F; Delruelle, N; Passardi, Giorgio; ten Kate, H H J

    2002-01-01

    The ATLAS central solenoid magnet has been designed and constructed as a collaborative work between KEK and CERN for the ATLAS experiment in the LHC project The solenoid provides an axial magnetic field of 2 Tesla at the center of the tracking volume of the ATLAS detector. The solenoid is installed in a common cryostat of a liquid-argon calorimeter in order to minimize the mass of the cryostat wall. The coil is cooled indirectly by using two-phase helium flow in a pair of serpentine cooling line. The cryogen is supplied by the ATLAS cryogenic plant, which also supplies helium to the Toroid magnet systems. The proximity cryogenic system for the solenoid has two major components: a control dewar and a valve unit In addition, a programmable logic controller, PLC, was prepared for the automatic operation and solenoid test in Japan. This paper describes the design of the proximity cryogenic system and results of the performance test. (7 refs).

  20. Vestibular effects of a 7 Tesla MRI examination compared to 1.5 T and 0 T in healthy volunteers.

    Jens M Theysohn

    Full Text Available Ultra-high-field MRI (7 Tesla (T and above elicits more temporary side-effects compared to 1.5 T and 3 T, e.g. dizziness or "postural instability" even after exiting the scanner. The current study aims to assess quantitatively vestibular performance before and after exposure to different MRI scenarios at 7 T, 1.5 T and 0 T. Sway path and body axis rotation (Unterberger's stepping test were quantitatively recorded in a total of 46 volunteers before, 2 minutes after, and 15 minutes after different exposure scenarios: 7 T head MRI (n = 27, 7 T no RF (n = 22, 7 T only B0 (n = 20, 7 T in & out B0 (n = 20, 1.5 T no RF (n = 20, 0 T (n = 15. All exposure scenarios lasted 30 minutes except for brief one minute exposure in 7 T in & out B0. Both measures were documented utilizing a 3D ultrasound system. During sway path evaluation, the experiment was repeated with eyes both open and closed. Sway paths for all long-lasting 7 T scenarios (normal, no RF, only B0 with eyes closed were significantly prolonged 2 minutes after exiting the scanner, normalizing after 15 minutes. Brief exposure to 7 T B0 or 30 minutes exposure to 1.5 T or 0 T did not show significant changes. End positions after Unterberger's stepping test were significantly changed counter-clockwise after all 7 T scenarios, including the brief in & out B0 exposure. Shorter exposure resulted in a smaller alteration angle. In contrast to sway path, reversal of changes in body axis rotation was incomplete after 15 minutes. 1.5 T caused no rotational changes. The results show that exposure to the 7 Tesla static magnetic field causes only a temporary dysfunction or "over-compensation" of the vestibular system not measurable at 1.5 or 0 Tesla. Radiofrequency fields, gradient switching, and orthostatic dysregulation do not seem to play a role.

  1. The magnetization transfer effect in brain studies by 1.5 T magnetic resonance system. When the radiographer should apply it?

    Ribeiro, M. Margarida, E-mail: margarida.ribeiro@estesl.ipl.p [Scientific Area of Radiology, Higher School of Health Technology, Polytechnic Institute of Lisbon (Portugal); Anatomy Department of Medicine Faculty, Medical Sciences University of Lisbon (Portugal); Farinha, Sara [Metelbea - Diagnostic and Therapeutic Centre of Lisbon (Portugal); Costa, Joana [Radiomedica, Lisbon (Portugal); Mauricio, J. Cruz [Anatomy Department of Medicine Faculty, Medical Sciences University of Lisbon (Portugal); Diamecon - Imaging Diagnostic Centre, Tomar (Portugal); O' Neill, J. Goyri [Anatomy Department of Medicine Faculty, Medical Sciences University of Lisbon (Portugal)

    2011-05-15

    Purpose: The Magnetization Transfer (MT) obtained by applying a pre-saturation pulse is, in Magnetic Resonance Imaging (MRI), a technique that allows for additional enhancement of lesions on conventional T1 images after contrast administration. This study aims to assess the effectiveness of the technique measuring how MT could improve image quality and diagnostic values through the enhancement of lesions. Methods: Thirteen T1-weighted spin-echo (SE) sequences, obtained by the 1.5 T system after contrast media injection, were analyzed with and without MT. The contrast-to-noise ratio (CNR), as well as the signal-to-noise ratio (SNR) variables were compared in all sequences, according to the reference structures: lateral ventricles, white matter, gray matter, caudate nucleus and internal capsule. The MT ratio average was calculated using the ANOVA scale in order to assess the CNR and the magnetization transfer effect (MTE) for the different lesions and for both sequences (with and without MT). For the assessment of the flow artifact, clinical experts applied a Likert scale with 5 points. Results: For CNR values, the differences between conventional and MT-pulsed images were significant (Student t testp < 0,05), remaining significant for SNR in all structures except for the lateral ventricles. For the flow artifacts the differences found by the coefficient Kappa agreement were not significant as the differences found for the CNR and the MTE between the two sequences (p > 0,05). Conclusion: In identical conditions of acquisition, the MT does not produce significant differences in the enhancement of lesions, however, it allows a greater capacity to detect the multiple sclerosis plaques, comparing structures around basal nucleus versus gray and white matter.

  2. Pulse on Pulse

    Schmidt, Ulrik; Carlson, Merete

    2012-01-01

    Pulse on Pulse” investigates the relation between signifying processes and non-signifying material dynamism in the installation Pulse Room (2006-) by Mexican Canadian artist Rafael Lozano-Hemmer. In Pulse Room the sense of pulse is ambiguous. Biorhythms are transmitted from the pulsing energy...... and pulsating ‘room’. Hence, the visitors in Pulse Room are invited into a complex scenario that continuously oscillates between various aspects of signification (the light bulbs representing individual lives; the pulse itself as the symbolic ‘rhythm of life’) and instants of pure material processuality...... a multilayered sense of time and space that is central to the sensory experience of Pulse Room as a whole. Pulse Room is, at the very same time, an anthropomorfized archive of a past intimacy and an all-encompassing immersive environment modulating continuously in real space-time....

  3. Failure Scenarios and Mitigations for the BABAR Superconducting Solenoid

    Thompson, EunJoo; Candia, A.; Craddock, W. W.; Racine, M.; Weisend, J. G.

    2006-04-01

    The cryogenic department at the Stanford Linear Accelerator Center is responsible for the operation, troubleshooting, and upgrade of the 1.5 Tesla superconducting solenoid detector for the BABAR B-factory experiment. Events that disable the detector are rare but significantly impact the availability of the detector for physics research. As a result, a number of systems and procedures have been developed over time to minimize the downtime of the detector, for example improved control systems, improved and automatic backup systems, and spares for all major components. Together they can prevent or mitigate many of the failures experienced by the utilities, mechanical systems, controls and instrumentation. In this paper we describe various failure scenarios, their effect on the detector, and the modifications made to mitigate the effects of the failure. As a result of these modifications the reliability of the detector has increased significantly with only 3 shutdowns of the detector due to cryogenics systems over the last 2 years.

  4. Development of the Butt Joint for the ITER Central Solenoid

    Martovetsky, N N

    2006-08-23

    The ITER Central Solenoid (CS) requires compact and reliable joints for its Cable-in-Conduit Conductor (CICC). The baseline design is a diffusion bonded butt joint. In such a joint the mating cables are compacted to a very low void fraction in a copper sleeve and then heat treated. After the heat treatment the ends are cut, polished and aligned against each other and then diffusion bonded under high compression in a vacuum chamber at 750 C. The jacket is then welded on the conductor to complete the joint, which remarkably does not require more room than a regular conductor. This joint design is based on a proven concept developed for the ITER CS Model Coil that was successfully tested in the previous R&D phase.

  5. Design Construction and Test Results of a HTS Solenoid For Energy Recovery Linac

    Anerella, M; Ben-Zvi, I; Kayran, D; McIntyre, G; Muratore, J; Plate, S; Sampson, W; Cole, M

    2011-03-28

    An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at {approx}77 K is simpler and cheaper than 4 K testing. This paper will present the design, construction and test results of this HTS solenoid. The HTS solenoid in the proposed ERL will be situated in the transition region between the superconducting cavity at {approx}4 K and the cryostat at the room temperature. Solenoid inside the cryogenic structure provides an early focusing and hence low emittance beam. The temperature in the transition region will be too high for a conventional low temperature superconductor and resistive heat load from copper coils will be too high on cryogenic system. HTS coils also allow much higher current density and significant reduction in size as compared to copper coils. Hence HTS solenoid provide a unique and technically superior solution. The use of a HTS solenoid with superconducting cavity offers a unique option as it can be placed in a cold to warm transition region to provide early focussing without using additional space. Construction and test results so far are very encouraging for its use in the ERL project.

  6. MRI evaluation of the anterolateral ligament of the knee: assessment in routine 1.5-T scans

    Partezani Helito, Camilo; Pecora, Jose Ricardo; Camanho, Gilberto Luis; Kawamura Demange, Marco [University of Sao Paulo, Faculty of Medicine, Institute of Orthopedics and Traumatology, Knee Surgery Division, Sao Paulo (Brazil); Partezani Helito, Paulo Victor; Pereira Costa, Hugo; Bordalo-Rodrigues, Marcelo [University of Sao Paulo, Faculty of Medicine, Institute of Orthopedics and Traumatology, Musculoskeletal Radiology Department, Sao Paulo (Brazil)

    2014-10-15

    This study evaluated the ability of routine 1.5-T MRI scans to visualize the anterolateral ligament (ALL) and describe its path and anatomic relations with lateral knee structures. Thirty-nine 1.5-T MRI scans of the knee were evaluated. The scans included an MRI knee protocol with T1-weighted sequences, T2-weighted sequences with fat saturation, and proton density (PD)-weighted fast spin-echo sequences. Two radiologists separately reviewed all MRI scans to evaluate interobserver reliability. The ALL was divided into three portions for analyses: femoral, meniscal, and tibial. The path of the ALL was evaluated with regard to known structural parameters previously studied in this region. At least a portion of the ALL was visualized in 38 (97.8 %) cases. The meniscal portion was most visualized (94.8 %), followed by the femoral (89.7 %) and the tibial (79.4 %) portions. The three portions of the ALL were visualized in 28 (71.7 %) patients. The ALL was characterized with greater clarity on the coronal plane and was visualized as a thin, linear structure. The T1-weighted sequences showed a statistically inferior ligament visibility frequency. With regard to the T2 and PD evaluations, although the visualization frequency in PD was higher for the three portions of the ligament, only the femoral portion showed significant values. The ALL can be visualized in routine 1.5-T MRI scans. Although some of the ligament could be depicted in nearly all of the scans (97.4 %), it could only be observed in its entirety in about 71.7 % of the tests. (orig.)

  7. Orbital parameters of proton and deuteron beams in the NICA collider with solenoid Siberian snakes

    Kovalenko, A. D.; Butenko, A. V.; Kekelidze, V. D.; Mikhaylov, V. A.; Kondratenko, M. A.; Kondratenko, A. M.; Filatov, Yu N.

    2016-02-01

    Two solenoid Siberian snakes are required to obtain ion polarization in the “spin transparency” mode of the NICA collider. The field integrals of the solenoid snakes for protons and deuterons at maximum momentum of 13.5 GeV/c are equal to 2×50 T·m and 2×160 T·m respectively. The snakes introduce strong betatron oscillation coupling. The calculations of orbital parameters of proton and deuteron beams in NICA collider with solenoid snakes are presented.

  8. A 1.5 T transverse magnetic field in radiotherapy of rectal cancer: Impact on the dose distribution

    Uilkema, Sander, E-mail: s.uilkema@nki.nl; Heide, Uulke van der; Sonke, Jan-Jakob; Triest, Baukelien van; Nijkamp, Jasper [Department of Radiotherapy, NKI-AVL, Amsterdam 1066 CX (Netherlands); Moreau, Michel [RTP Research Group, Elekta, Maryland Heights, Missouri 63043 (United States)

    2015-12-15

    Purpose: MRI guidance during radiotherapy has the potential to enable more accurate dose delivery, optimizing the balance between local control and treatment related toxicity. However, the presence of a permanent magnetic field influences the dose delivery, especially around air cavities. Here, electrons are able to return to the surface through which they entered the air cavity (electron return effect, ERE) locally resulting in dose hot- and cold-spots. Where RT of rectal cancer patients might benefit from MRI guidance for margin reduction, air cavities in and around the target volume are frequently present. The purpose of this research is to evaluate the impact of the presence of a 1.5 T transverse magnetic field on dose delivery in patients with rectal cancer. Methods: Ten patients treated with 5 × 5 Gy RT having large changes in pelvic air content were selected out of a cohort of 33 patients. On the planning CT, a 1.5 T, 6 MV, 7-field intensity modulated radiotherapy (IMRT) plan was created. This plan was subsequently recalculated on daily CT scans. For each daily CT, the CTV V{sub 95%} and V{sub 107%} and bowel area V{sub 5Gy}, V{sub 10Gy}, V{sub 15Gy}, V{sub 20Gy}, and V{sub 25Gy} were calculated to evaluate the changes in dose distribution from fraction to fraction. For comparison, the authors repeated this procedure for the 0 T situation. To study the effect of changing air cavities separate from other anatomical changes, the authors also generated artificial air cavities in the CTV of one patient (2 and 5 cm diameter), in the high dose gradient region (2 cm), and in the low dose area (2 cm). Treatment plans were optimized without and with each simulated air cavity. For appearing and disappearing air cavities, the CTV V{sub 95%} and V{sub 107%} were evaluated. The authors also evaluated the ERE separate from attenuation changes locally around appearing gas pockets. Results: For the ten patients, at 1.5 T, the V{sub 95%} was influenced by both appearing and disappearing air, and dropped to <98% in 2 out of 50 fractions due a disappearing air cavity of 150 cm{sup 3}. V{sub 95%} differences between 0 and 1.5 T were all within 2%. The V{sub 107%} was below 1% in 46 out of 50 fractions, and increased to 3% in the remaining fractions due to appearing air of around 120 cm{sup 3}. For comparison, V{sub 107%} was <1% at 0 T for all fractions. In the bowel area, the V{sub 15Gy} varied strongest from fraction to fraction, but differences between 1.5 and 0 T were minimal with an average difference of 2.3 cm{sup 3} (SD = 18.7 cm{sup 3}, p = 0.38). For the simulated air cavities, the ERE resulted in cold-spots maximally 5% lower than prescribed and hot-spots maximally 6% higher than prescribed. Conclusions: The presence of a 1.5 T magnetic field has an impact on the dose distribution when the air content changes of within a few percent in these selected rectal cancer patients. The authors consider this influence of the transverse magnetic field on the dose distribution in IMRT for rectal cancer patients clinically acceptable.

  9. Impact of detector solenoid on the Compact Linear Collider luminosity performance

    Levinsen, Yngve Inntjore; Tomas, Rogelio; Schulte, Daniel

    2014-01-01

    In order to obtain the necessary luminosity with a reasonable amount of beam power, the Compact Linear Collider (CLIC) design includes an unprecedented collision beam size of {\\sigma} = 1 nm vertically and {\\sigma} = 45 nm horizontally. Given the small and very flat beams, the luminosity can be significantly degraded from the impact of the experimental solenoid field in combination with a large crossing angle. Main effects include y-x'-coupling and increase of vertical dispersion. Additionally, Incoherent Synchrotron Radiation (ISR) from the orbit deflection created by the solenoid field, increases the beam emittance. A detailed study of the impact from a realistic solenoid field and the associated correction techniques for the CLIC Final Focus is presented. In particular, the impact of techniques to compensate the beam optics distortions due to the detector solenoid main field and its overlap with the final focus magnets are shown. The unrecoverable luminosity loss due to ISR has been evaluated, and found to...

  10. The electromagnetic calorimeter for the solenoidal tracker at RHIC. A Conceptual Design Report

    Beddo, M.E.; Bielick, E.; Dawson, J.W. [Argonne National Lab., IL (United States)] [and others; The STAR EMC Collaboration

    1993-09-22

    This report discusses the following on the electromagnetic calorimeter for the solenoidal tracker at RHIC: conceptual design; the physics of electromagnetic calorimetry in STAR; trigger capability; integration into STAR; and cost, schedule, manpower, and funding.

  11. The influence of the iron shield of the solenoid on spin tracking

    Toprek Dragan

    2005-01-01

    Full Text Available The influence of the iron shield of the solenoid on spin tracking is studied in this paper. In the case of the 200 MeV proton, the study has been numerically done in the ZGOUBI code. The distribution of the magnetic field was done by POISSON. We have come to the conclusion that the influence of the solenoid’s shielding on spin tracking is the same at its entrance and exit and that is directly proportional to the intensity of the magnetic induction B on the axis of the solenoid. We have also determined that the influence of the solenoid’s shielding is much stronger on transversal components of the spin than on its longitudinal component. The differences between components of the spin for the shielded and not-shielded solenoid diminish with the in crease in the distance from the solenoid.

  12. Detecting Solenoid Valve Deterioration in In-Use Electronic Diesel Fuel Injection Control Systems

    Chyuan-Yow Tseng; Hsun-Heng Tsai

    2010-01-01

    The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to oc...

  13. Approach control of a gas exchange solenoid actuator for IC engines

    Tsai, Chun-Ming

    2007-01-01

    Application of solenoid valve actuators in internal combustion engines can facilitate operations such as variable valve timing for improved efficiency and emission. Unfortunately, smooth solenoid valve landing is hard to achieve due to limited control authority, limited bandwidth, and time varying disturbances. The resultant valve impact causes unacceptable noise and component wear on the engine. To solve this ``soft seating" problem, the controller is further divided into approach and landin...

  14. Conceptual design report for the Solenoidal Tracker at RHIC

    The STAR Collaboration

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it`s experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  15. the LHC Compact Muon Solenoid experiment detector control system

    Gomez-Reino Garrido, Robert

    2011-01-01

    The Compact Muon Solenoid (CMS) experiment at CERN is a multi-purpose experiment designed to exploit the physics of proton-proton collisions at the Large Hadron Collider collision energy (14TeV at centre of mass) over the full range of expected luminosities (up to 1034cm-2s-1). CMS detector control system (DCS) responsibility is to ensure a safe, correct and efficient operation of the detector so that high quality physics data can be recorded. The system is also required to make possible that inexperienced shifters can operate the detector and a small crew of experts can take care of the maintenance of its software and hardware infrastructure. The DCS large subsystems size sum up to more than a million parameters that need to be supervised. A cluster of roughly 100 servers is used to provide the required processing resources. A scalable approach has been chosen factorizing the DCS system as much as possible. CMS DCS has made clear division between its computing resources and functionality by creating a comput...

  16. Superconducting Solenoid and Press for Permanent Magnet Fabrication

    Mulcahy, T. M.; Hull, J. R.

    2002-08-01

    For the first time, a superconducting solenoid (SCM) was used to increase the remnant magnetization of sintered NdFeB permanent magnets (PMs). In particular, improved magnetic alignment of commercial-grade PM powder was achieved, as it was axial die pressed into 12.7-mm diameter cylindrical compacts in the 76.2-mm warm bore of a 9-T SCM. The press used to compact the powder is unique and was specifically designed for use with the SCM. Although the press was operated in the batch mode for this proof of concept study, its design is intended to enable automated production. In operation, a simple die and punch set made of nonmagnetic materials was filled with powder and loaded into a nonmagnetic press tube. The cantilevered press tube was inserted horizontally, on a carrier manually advanced along a track, into the SCM. The robustness of the mechanical components and the SCM, in its liquid helium dewar, were specifically designed to allow for insertion and extraction of the magnetic powder and compacts, while operating at 9 T.

  17. An implantable RF solenoid for magnetic resonance microscopy and microspectroscopy.

    Rivera, D S; Cohen, M S; Clark, W G; Chu, A C; Nunnally, R L; Smith, J; Mills, D; Judy, J W

    2012-08-01

    Miniature solenoids routinely enhance small volume nuclear magnetic resonance imaging and spectroscopy; however, no such techniques exist for patients. We present an implantable microcoil for diverse clinical applications, with a microliter coil volume. The design is loosely based on implantable depth electrodes, in which a flexible tube serves as the substrate, and a metal stylet is inserted into the tube during implantation. The goal is to provide enhanced signal-to-noise ratio (SNR) of structures that are not easily accessed by surface coils. The first-generation prototype was designed for implantation up to 2 cm, and provided initial proof-of-concept for microscopy. Subsequently, we optimized the design to minimize the influence of lead inductances, and to thereby double the length of the implantable depth (4 cm). The second-generation design represents an estimated SNR improvement of over 30% as compared to the original design when extended to 4 cm. Impedance measurements indicate that the device is stable for up to 24 h in body temperature saline. We evaluated the SNR and MR-related heating of the device at 3T. The implantable microcoil can differentiate fat and water peaks, and resolve submillimeter features.

  18. How MRI Compatible is 'MRI Compatible'? A Systematic Comparison of Artifacts Caused by Biopsy Needles at 3.0 and 1.5 T

    Penzkofer, Tobias, E-mail: tpenzkofer@ukaachen.de [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology (Germany); Peykan, Nilufar [Klinikum Osnabrueck, Roentgen- und Strahlenklinik (Germany); Schmidt, Katja [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology (Germany); Krombach, Gabriele [Justus-Liebig University Giessen, Department of Radiology (Germany); Kuhl, Christiane K. [RWTH Aachen University Hospital, Department of Diagnostic and Interventional Radiology (Germany)

    2013-12-15

    Purpose: This study was designed to systematically investigate artifacts caused by interventional needles recommended for use in MRI, with focus on field strength, needle/mandrin type, orientation and sequence. Methods: Eight different MRI compatible needles were placed in porcine tissue and examined at 1.5 and 3.0 T with balanced-steady-state-free-precession (B-SSFP) and T1-weighted-spoiled-gradient-echo (T1-SPGR) sequences in different orientations to B{sub 0}. Artifact diameters with regards to the primary, inner, and secondary, outer artifacts were assessed and statistically evaluated. Results: The types and degree of artifacts varied considerably, especially between different mandrin types even for the same needles. Orientation of the needle in the magnetic field was another main contributor to the artifact dimensions. Less important factors were the type of pulse sequence and field strength. Artifacts ranged from 0.7 mm (steel, 0 Degree-Sign , B-SSFP, 3.0 T, inner) to 71.4 mm (nitinol, 90 Degree-Sign , B-SSFP, 1.5 T, outer). Inner artifact diameters in B-SSFP were slightly larger (8.2 {+-} 5.7 mm) than those in T1-SPGR (7.6 {+-} 5.4 mm) and comparable between 1.5 and 3.0 T (e.g., 8.0 vs. 8.4 mm, B-SSFP). Conclusions: Although all were sold as 'MR compatible,' the artifacts differed greatly between needle types, and even more so for different mandrins. The results suggest an empirical approach to the needle choice based on lesion type and approach angle.

  19. SU-E-J-203: Investigation of 1.5T Magnetic Field Dose Effects On Organs of Different Density

    Lee, H; Rubinstein, A; Ibbott, G [UT MD Anderson Cancer Center, Houston, TX (United States)

    2015-06-15

    Purpose: For the combined 1.5T/6MV MRI-linac system, the perpendicular magnetic field to the radiation beam results in altered radiation dose distributions. This Monte Carlo study investigates the change in dose at interfaces for common organs neighboring soft tissue. Methods: MCNP6 was used to simulate the effects of a 1.5T magnetic field when irradiating tissues with a 6 MV beam. The geometries used in this study were not necessarily anatomically representative in size in order to directly compare quantitative dose effects for each tissue at the same depths. For this purpose, a 512 cm{sup 3} cubic material was positioned at the center of a 2744 cm{sup 3} cubic soft tissue material phantom. The following tissue materials and their densities were used in this study: lung (0.296 g/cm{sup 3}), fat (0.95), spinal cord (1.038), soft tissue (1.04), muscle (1.05), eye (1.076), trabecular bone (1.40), and cortical bone (1.85). Results: The addition of a 1.5T magnetic field caused dose changes of +46.5%, +2.4%, −0.9%, −0.8%, −1.5%, −6.5%, and −8.8% at the entrance interface between soft tissue and lung, fat, spinal cord, muscle, eye, trabecular bone, and cortical bone tissues respectively. Dose changes of −39.4%, −4.1%, −0.8%, −0.8%, +0.5%, +6.7%, and +10.9% were observed at the second interface between the same tissues respectively and soft tissue. On average, the build-up distance was reduced by 0.6 cm, and a dose increase of 62.7% was observed at the exit interface between soft tissue and air of the entire phantom. Conclusion: The greatest changes in dose were observed at interfaces containing lung and bone tissues. Due to the prevalence and proximity of bony anatomy to soft tissues throughout the human body, these results encourage further examination of these tissues with anatomically representative geometries using multiple beam configurations for safe treatment using the MRI-linac system.

  20. ANALYSIS OF THE PROCESSES IN AN INDUCTOR SYSTEM WITH AN ATTRACTING SCREEN EXCITED BY THE EXTERNAL CIRCULAR SOLENOID

    E.A. Chaplygin

    2015-12-01

    Full Text Available Introduction. Developments in the field of magnetic-pulse treatment of metals (MPTM are increasingly used in the modern technologies of production and repair of the aviation, automotive and other machinery, as they are environmentally friendly and energy-efficient in comparison with classical approaches. One of the main components of the device MPTM is a tool – inductor or the inductor system with an attractive screen (ISAS. The calculated dependences to calculate the inductor system with an attractive screen were taken from previous works. The ratios were obtained for the low-frequency mode of the excited fields, when is place their significant penetration through a thin-walled metal screen and a deformed workpiece. As it was shown earlier this mode is the most efficient from point of view of a force action on the object of a processing. Purpose. The theoretical analysis of the spatial-temporal distributions of the induced currents and forces of an attraction in the inductor system with an attractive screen excited by a flat circular solenoid located on the outside of the auxiliary screen. Methodology. The calculations are shown that the induced currents both in the screen and the workpiece are unidirectional and their interaction, in accordance with the law of Ampere determines the amplitudes of excited forces of attraction. Let’s note the effective validity of the considered inductor system excited by an external circular solenoid. With sufficient simplicity of the design take place rather high values of the developed forces of attraction and their averages. Results. Physically, a higher power efficiency of the system with an «external» coil in comparison with a system where coil is located in the internal cavity, can be accounted for lade of «failure» in the radial distribution of the excited forces. This «failure» in the design with a coil between the sheet metal is caused by its screening action against the forces of attraction

  1. Effect of a Static Magnetic Field (1.5T) on Brain Oscillatory Activities in Resting State Condition.

    Formaggio, E; Avesani, M; Storti, S F; Milanese, F; Gasparini, A; Acler, M; Cerini, R; Pozzi Mucelli, R; Fiaschi, A; Manganotti, P

    2008-12-17

    The aim of the present study was to compare the EEG signal recorded outside and inside a 1.5T magnetic resonance (MR) scanner. The EEG was recorded in eyes open and eyes closed conditions using a digital recording MR-compatible system. To characterize how a static magnetic field induces changes in EEG signal, EEG data were analyzed using FFT frequency analysis. No significant difference between the alpha powers recorded outside and inside the magnetic field was observed in eyes closed conditions. However, in eyes open condition there was a significant increase in alpha power inside the magnet in comparison to the outside position. The changes in alpha power according to the eyes open/closed conditions could be inversely correlated to a subject's state of wakefulness and due to some physiological changes, rather than an effect of the magnetic field. This experiment suggests that subjects' state of wakefulness is of prime concern when performing functional MRI.

  2. Cortical projections to the human red nucleus: a diffusion tensor tractography study with a 1.5-T MRI machine

    Habas, Christophe; Cabanis, Emmanuel Alain [Universite Pierre et Marie Curie Paris 6, Service de Neuroimagerie, Centre Hospitalier National d' Optalmologie des Quinze-Vingts, Paris (France)

    2006-10-15

    Previous studies in apes and monkeys have shown that the red nucleus receives projections from the sensorimotor and premotor cortices, whereas other experiments carried out with injured human brains have found corticorubral projections issuing from associative areas. Therefore, we reassessed in vivo the human anatomical projections from the cerebral cortex to the red nucleus using diffusion tensor imaging (DTI) axonal tracking. The connectivity between the cerebral cortex and the red nuclei of seven volunteers was studied at 1.5 T using streamlined DTI axonal tracking. Trajectories were constantly tracked between the red nuclei and the ipsilateral pericentral and prefrontal cortices, as well as the temporal cortex and the striatum in two subjects. Within the cerebral trunk, trajectories also include the superior cerebellar peduncle and the central tegmental tract. The human red nucleus receives its main afferences from the sensorimotor and prefrontal cortices. (orig.)

  3. MR microscopy of articular cartilage at 1.5 T: orientation and site dependence of laminar structures

    Yoshioka, Hiroshi; Anno, Izumi; Echigo, Junko; Itai, Yuji [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575 (Japan); Haishi, Tomoyuki; Uematsu, Takaaki; Matsuda, Yoshimasa; Kose, Katsumi [Institute of Applied Physics, University of Tsukuba, Tsukuba (Japan); Lang, Philipp [Department of Radiology, Brigham and Women' s Hospital, Boston, Massachusetts (United States)

    2002-09-01

    Abstract Objective. To evaluate MR microscopic images of normal-appearing porcine hyaline cartilage (n=15) in vitro obtained with an MR microscope using an independent console system (MRMICS) at 1.5 T.Design and results. The MRMICS is a portable imaging system consisting of a radiofrequency system, gradient power supplies and a personal computer. The images from the MRMICS showed a laminar structure of porcine cartilage similar to the structure demonstrated with other MR imaging techniques. The laminar structures of the articular cartilage, were, however heterogeneous in respect of signal intensity and thickness, which varied according to the site resected. The MR laminar appearance was most comparable to the staining with Masson's trichrome for collagen.Conclusion. MRMICS is a useful add-on system for obtaining microscopic MR images of articular cartilage in vitro. (orig.)

  4. Cardiac MRI, How Much can be Performed on a 1.5T Magnet with Basic Cardiac Sequences?

    Sepideh Sefidbakht*

    2012-05-01

    Full Text Available Background/Objective: To present our first 8-month experience with cardiac MRI (1.5T, Siemens Avanto magnet, Argus viewer spectrum of local referrals and outcomes.Materials and Methods: The population included 24 patients, (five female, 19 male reffered for evaluation of possible arrhythmogenic right ventricular dysplasia (ARVD (11, myocarditis (5, ischemic scar (2 and miscellaneous cases (6 including myocardial cyst, papillary muscle lipoma, straight back syndrome (ruling out absent pericardium, possible pericarditis, Brugada syndrome and one case of later biopsy proven cardiac amyloidosis. Retrorecon, truFisp cine images were obtained in SA, 2 and 4 chamber views. T1 flash images were taken with/ without fat-saturation. T2HASTE and SA STIR images were obtained. Postcontrast delayed enhancement images were taken (PSIR tFla or Trufisp. Dynamic perfusion images were obtained in two cases. For DE images, TI 160-360 was manually selected one image at a time and optimal myocardial nulling was selected visually and subjectively. Results: Out of 11 patients reffered for possible ARVD, four patients showed regional dys/akinesia; with an EF<40% this was considered a major criterion. Three of the mentioned patients as well as two patients without obvious dyskinesia showed delayed RV freewall enhancement. Out of five patients referred with possible myocarditis, three showed patchy subepicardial enhanecement which confirmed the diagnosis, and two showed nonspecific transmural edema and/or enhancement. Ischemic scar was observed in two.Conclusion: Although far less than perfect, the basic MRI sequences provided by many vendors on 1.5T magnets can be helpful in selected cases of cardiac disease when referral to centers with a higher level of expertise and equipment is not feasible.

  5. Accuracy of 3 T versus 1.5 T breast MRI for pre-operative assessment of extent of disease in newly diagnosed DCIS

    Rahbar, Habib, E-mail: hrahbar@uw.edu; DeMartini, Wendy B.; Lee, Amie Y.; Partridge, Savannah C.; Peacock, Sue; Lehman, Constance D.

    2015-04-15

    Highlights: •We compared sizes of known ductal carcinoma in situ (DCIS) on pre-operative breast MRI at 3 T and 1.5 T with final pathology sizes. •DCIS sizes on 3 T MRI correlated better with pathologic sizes than 1.5 T MRI. •Imaging features of DCIS, including morphology and kinetics, were similar at 3 T and 1.5 T MRI. -- Abstract: Objectives: While 3 T breast magnetic resonance imaging has increased in use over the past decade, there is little data comparing its use for assessing ductal carcinoma in situ (DCIS) versus 1.5 T. We sought to compare the accuracies of DCIS extent of disease measures on pre-operative 3 T versus 1.5 T MRI. Methods: This institutional review board-approved prospective study included 20 patients with ductal carcinoma in situ diagnosed by core needle biopsy (CNB) who underwent pre-operative breast MRI at both 3 T (resolution = 0.5 mm × 0.5 mm × 1.3 mm) and 1.5 T (0.85 mm × 0.85 mm × 1.6 mm). All patients provided informed consent, and the study was HIPPA compliant. Lesion sizes and imaging characteristics (morphologic and kinetic enhancement) were recorded for the 3 T and 1.5 T examinations. Lesion size measures at both field strengths were correlated to final pathology, and imaging characteristics also were compared. Results: Of the initial cohort of 20 patients with CNB-diagnosed DCIS, 19 underwent definitive surgery. Median DCIS sizes of these 19 patients were 6 mm (range: 0–67 mm) on 3 T, 13 mm (0–60 mm) on 1.5 T, and 6 mm (0–55 mm) on surgical pathology. Size correlation between MRI and pathology was higher for 3 T (Spearman's ρ = 0.66, p = 0.002) than 1.5 T (ρ = 0.36, p = 0.13). In 10 women in which a residual area of suspicious enhancement was identified on both field strengths, there was agreement of morphologic description (NME vs. mass) in nine, and no significant difference in dynamic contrast enhanced kinetics at 3 T compared to 1.5 T. Conclusions: Pre-operative breast MRI at 3 T provided higher correlation with final pathology size of DCIS lesions compared to 1.5 T, and may be more accurate for assessment of disease extent prior to definitive surgery.

  6. Conceptual design report for the Solenoidal Tracker at RHIC

    1992-06-15

    The Solenoidal Tracker At RHIC (STAR) will search for signatures of quark-gluon plasma (QGP) formation and investigate the behavior of strongly interacting matter at high energy density. The emphasis win be the correlation of many observables on an event-by-event basis. In the absence of definitive signatures for the QGP, it is imperative that such correlations be used to identify special events and possible signatures. This requires a flexible detection system that can simultaneously measure many experimental observables. The physics goals dictate the design of star and it's experiment. To meet the design criteria, tracking, momentum analysis, and particle identification of most of the charged particles at midrapidity are necessary. The tracking must operate in conditions at higher than the expected maximum charged particle multiplicities for central Au + Au collisions. Particle identification of pions/kaons for p < 0.7 GeV/c and kaons/protons for p < 1 GeV/c, as well as measurement of decay particles and reconstruction of secondary vertices will be possible. A two-track resolution of 2 cm at 2 m radial distance from, the interaction is expected. Momentum resolution of {Delta}p/p {approximately} 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,{Delta}p/p of several percent at p = 10 GeV/c is sufficient to accurately measure the rapidly failing spectra at high Pt and particles from mini-jets and jets.

  7. Detecting Solenoid Valve Deterioration in In-Use Electronic Diesel Fuel Injection Control Systems

    Chyuan-Yow Tseng

    2010-07-01

    Full Text Available The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves.

  8. Detecting solenoid valve deterioration in in-use electronic diesel fuel injection control systems.

    Tsai, Hsun-Heng; Tseng, Chyuan-Yow

    2010-01-01

    The diesel engine is the main power source for most agricultural vehicles. The control of diesel engine emissions is an important global issue. Fuel injection control systems directly affect fuel efficiency and emissions of diesel engines. Deterioration faults, such as rack deformation, solenoid valve failure, and rack-travel sensor malfunction, are possibly in the fuel injection module of electronic diesel control (EDC) systems. Among these faults, solenoid valve failure is most likely to occur for in-use diesel engines. According to the previous studies, this failure is a result of the wear of the plunger and sleeve, based on a long period of usage, lubricant degradation, or engine overheating. Due to the difficulty in identifying solenoid valve deterioration, this study focuses on developing a sensor identification algorithm that can clearly classify the usability of the solenoid valve, without disassembling the fuel pump of an EDC system for in-use agricultural vehicles. A diagnostic algorithm is proposed, including a feedback controller, a parameter identifier, a linear variable differential transformer (LVDT) sensor, and a neural network classifier. Experimental results show that the proposed algorithm can accurately identify the usability of solenoid valves.

  9. Manufacture and Test of a Small Ceramic-Insulated Nb$_{3}$Sn Split Solenoid

    Bordini, B; Rossi, L; Tommasini, D

    2008-01-01

    A small split solenoid wound with high-Jc Nb3Sn conductor, constituted by a 0.8 mm Rod Re-stack Process (RRP®) strand, was built and tested at CERN in order to study the applicability of: 1) ceramic wet glass braid insulation without epoxy impregnation of the magnet; 2) a new heat treatment devised at CERN and particularly suitable for reacting RRP® Nb3Sn strands. This paper briefly describes the solenoid and the experimental results obtained during 4.4 K and 1.9 K tests. The split solenoid consists of two coils (25 mm inner diameter, 51.1 mm outer diameter, 12.9 mm height). The coils were initially separately tested, in an iron mirror configuration, and then tested together in split solenoid configuration. In all the tests at 4.4 K the coils reached a current higher than 95 % of their short sample limits at the first quench; in split solenoid configuration the maximum field values in the coils and in the aperture were respectively 10.7 T and 12.5 T. At 1.9 K the coils had premature quenches due to self fi...

  10. Hybrid design method for air-core solenoid with axial homogeneity

    Huang, Li; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of); Choi, Suk Jin [Institute for Basic Science, Daejeon (Korea, Republic of)

    2016-03-15

    In this paper, a hybrid method is proposed to design an air-core superconducting solenoid system for 6 T axial uniform magnetic field using Niobium Titanium (NbTi) superconducting wire. In order to minimize the volume of conductor, the hybrid optimization method including a linear programming and a nonlinear programming was adopted. The feasible space of solenoid is divided by several grids and the magnetic field at target point is approximated by the sum of magnetic field generated by an ideal current loop at the center of each grid. Using the linear programming, a global optimal current distribution in the feasible space can be indicated by non-zero current grids. Furthermore the clusters of the non-zero current grids also give the information of probable solenoids in the feasible space, such as the number, the shape, and so on. Applying these probable solenoids as the initial model, the final practical configuration of solenoids with integer layers can be obtained by the nonlinear programming. The design result illustrates the efficiency and the flexibility of the hybrid method. And this method can also be used for the magnet design which is required the high homogeneity within several ppm (parts per million)

  11. Novel Peak Assignments of in Vivo 13C MRS in Human Brain at 1.5 T

    Blüml, Stefan; Hwang, Jong-Hee; Moreno, Angel; Ross, Brian D.

    2000-04-01

    13C MRS studies at natural abundance and after intravenous 1-13C glucose infusion were performed on a 1.5-T clinical scanner in four subjects. Localization to the occipital cortex was achieved by a surface coil. In natural abundance spectra glucose C3β,5β, myo-inositol, glutamate C1,2,5, glutamine C1,2,5, N-acetyl-aspartate C1-4,Cdbnd O, creatine CH2, CH3, and CCdbnd N, taurine C2,3, bicarbonate HCO-3 were identified. After glucose infusion 13C enrichment of glucose C1α,1β, glutamate C1-4, glutamine C1-4, aspartate C2,3, N-acetyl-aspartate C2,3, lactate C3, alanine C3, and HCO-3 were observed. The observation of 13C enrichment of resonances resonating at >150 ppm is an extension of previously published studies and will provide a more precise determination of metabolic rates and substrate decarboxylation in human brain.

  12. Improvement of brain angiographic images using 1.5t super conductive MRI unit of Imam Khomeini Hospital

    "Takavar A

    2002-05-01

    Full Text Available Fue to the importance of selecting imaging parameters in magnetic resonance brain angiography, this study was carried out to choose optimum theoretical and experimental parameters for improving image controast and resolution and achieve shorter imaging time for practical reasons.A 1.5T super conductive magnet MRI with gradient power of 13 nT/m and Larmour frequency of 63 MHz with imaging coli of 30 cm was used.In this study, 5 healthy volunteers and 34 patients were the subjects of brain angiography. Flip angles of 15-20 degrees for peripheral brain vessels and 35-45 degrees for internal brain vessels were found to give higher contrast and better image resolution with a artifact. Using our optimum imaging parameters, (ie [TR/Te/FA/FOV] [40ms/7cm/20°/1mm 023cm], besides obtaining high quality angiography images, routine imaging time of 9-12 minutes was reduced to 7.3 mintues

  13. Influence of solenoid valve response times on water hammer in variable rate spraying system%变量喷施系统电磁阀响应时间对液压冲击的影响

    周兴祥; 刘海红; 吴姝; 魏新华

    2016-01-01

    could predict water hammer pressure generated by solenoid valve’s closing process in PWM controlled variable rate spraying system with high frequencies. However, the indirect water hammer pressure formula could not calculate water hammer pressure generated by solenoid valve’s opening process directly. Nevertheless, when the response times were the same, the water hammer pressures generated by solenoid valve’s opening process were linearly related with those generated by solenoid valve’s closing process, and the proportionality factor was 1.91 and the coefficient of determination was 0.99. This study was helpful in understanding the influence of solenoid valve’s structure parameters on water hammer and in building the simulation model for the whole PWM variable rate spraying system and for optimizing the spraying system.%为研究电磁阀响应时间对脉冲宽度调制(pulse width modulation,PWM)变量喷施系统液压冲击的影响,该文构建PWM变量喷施系统流道的三维仿真模型,设定不同的电磁阀开启和闭合时间,利用Fluent软件模拟分析了电磁阀启闭时系统管路内液压冲击的变化。模拟结果表明:电磁阀启闭时所产生的液压冲击随电磁阀响应时间的增加而减小。利用PWM变量喷施系统对电磁阀启闭过程中的管路压力变化进行了试验测试,试验结果与模拟结果吻合,最大水击压强之间的相对误差小于10%。对电磁阀闭合所引起的液压冲击进行理论分析,间接最大水击压强公式适用于PWM变量喷施系统中电磁阀高速闭合时所引起的液压冲击的计算,并且电磁阀开启与闭合所引起的液压冲击呈线性关系,比例系数为1.91。研究可为系统中其他液压元件动态特性的研究提供理论支持。

  14. Lingering fat signals with CHESS in simultaneous imaging of both hands can be improved with rice pads in both 1.5 T and 3.0 T

    Moriya, Susumu, E-mail: smoyari@yahoo.co.jp [Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942 (Japan); Ishikawa Clinic, 46-1 Shimokamo-Umenoki-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-0851 (Japan); Miki, Yukio, E-mail: yukio.miki@med.osaka-cu.ac.jp [Department of Radiology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Kamishima, Tamotsu, E-mail: ktamotamo2@yahoo.co.jp [Department of Biomedical Sciences and Engineering, Hokkaido University Graduate School of Health Science, North-12 West-5 Kita-ku, Sapporo 060-0812 (Japan); Miyati, Tosiaki, E-mail: ramiyati@mhs.mp.kanazawa-u.ac.jp [Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa 920-0942 (Japan); Kanagaki, Mitsunori, E-mail: mitsuk@kuhp.kyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University, 54 Shogoin-kawahara-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-8507 (Japan); Matsuno, Yukako, E-mail: ynoma2000jp@yahoo.co.jp [Oike Clinic, 11 Nishinokyo-Shimoai-cho, Nakagyo-ku, Kyoto-shi, Kyoto 604-8436 (Japan); Yokobayashi, Tsuneo, E-mail: mri@mrnet.jp [Ishikawa Clinic, 46-1 Shimokamo-Umenoki-cho, Sakyo-ku, Kyoto-shi, Kyoto 606-0851 (Japan)

    2013-09-15

    Objectives: To investigate whether rice pads can eliminate lingering fat signals of the complex surface shape of both hands that occur with chemical shift selective (CHESS) at 1.5 T and 3.0 T. Materials and methods: T1-weighted images were obtained with CHESS using 1.5 T and 3.0 T systems. The same imaging parameters were used with and without rice pads on the coronal plane of both hands in 10 healthy volunteers. The fat-suppression effects were classified into four categories and scored for images, and visual evaluations were performed by one radiologist and one radiologic technologist. Results: At 1.5 T, the mean evaluation score was 1.55 for images obtained without rice pads and 3.50 for images obtained with rice pads. At 3.0 T, the mean evaluation score was 1.10 for images obtained without rice pads and 3.20 for images obtained with rice pads. With both systems, images obtained with the rice pads showed significantly better fat suppression effects than images obtained without rice pads (P < 0.0001, P < 0.0001). Conclusions: It was confirmed that lingering fat signals are eliminated and good fat-suppressed images are obtained with the use of rice pads at 1.5 T and 3.0 T. Rice pads are therefore useful with at 1.5 T and 3.0 T, which are currently becoming more widely used.

  15. Variety of molecular conformation of plasmid pUC18 DNA and solenoidally supercoiled DNA

    黄熙泰; 王照清; 吴永文; 樊廷玉; 王树荣; 王勖焜

    1996-01-01

    The plasmid pUC18 DNA isolated from Escherichia coli HB101 were analyzed by two-dimensional agarose gel electrophoresis and hybridization. The results show that the DNA sample can be separated into six groups of different structural components. The plectonemically and solenoidally supercoiled pUC18 DNA coexist in it. These two different conformations of supercoiled DNA are interchangeable with the circumstances (ionic strength and type, etc.). The amount of solenoidally supercoiled pUC18 DNA in the samples can be changed by treatment of DNA topoisome rases. Under an electron microscope, the solenoidal supercoiling DNA has a round shape with an average diameter of 45 nm. The facts suggest that solenoidaUy supercoiled DNA be a structural entity independent of histones. The polymorphism of DNA structure may be important to packing of DNA in vivo.

  16. Application of High-speed Solenoid Valve to the Semi-active Control of Landing Gear

    Liu Hui; Gu Hongbin; Chen Dawei

    2008-01-01

    To select or develop an appropriate actuator is one of the key and difficult issues in the study of semi-active controlled landing gear.Performance of the actuator may directly affect the effectiveness of semi-active control.In this article,parallel high-speed solenoid valves are chosen to be the actuators for the semi-active controlled landing gear and being studied.A nonlinear high-speed solenoid valve model is developed with the consideration of magnctic saturation characteristics and verified by test.According to the design rule of keeping the peak load as small as possible while absorbing the specified shock energy,a fuzzy PD control rule is designed.By the rule,controller parameters can be self-regulated.The simulation results indicate that the semi-active control based on high-speed solenoid valve can effectively improve the control performance and reduce impact load during landing.

  17. Ferrite-Cored Solenoidal Induction Coil Sensor for BUD (MM-1667)

    Morrison, F.; Becker, A.; Conti, U.; Gasperikova, E.

    2011-06-15

    We have designed and lab tested a new ferrite cored induction coil sensor for measuring the secondary fields from metallic UXO with the BUD system. The objective was to replace the 5-inch diameter air-cored coils in the BUD system with smaller sensors that would allow the placement of multiple sensors in the smaller package of the new BUD hand-held system. A ferrite-cored solenoidal coil of length L can easily be made to have sensitivity and noise level roughly the same as an air-cored coil of a diameter on the same order as L. A ferrite-cored solenoidal coil can easily have a feedback configuration to achieve critical damping. The feedback configuration leads to a very stable response. Feedback ferrite-cored solenoidal coils show very little interaction as long as they are separated by one half their length.

  18. Development of solenoid-induced helical wiggler with four poles per period

    Ohigashi, N.; Tsunawaki, Y.; Kiyochi, M.; Nakao, N.; Fujita, M.; Imasaki, K.; Nakai, S.; Mima, K.

    1999-06-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field.

  19. Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion source.

    Kondo, K; Yamamoto, T; Sekine, M; Okamura, M

    2012-02-01

    The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (∼100 μA) with high charge (∼10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

  20. Laser ion source with solenoid for Brookhaven National Laboratory-electron beam ion sourcea)

    Kondo, K.; Yamamoto, T.; Sekine, M.; Okamura, M.

    2012-02-01

    The electron beam ion source (EBIS) preinjector at Brookhaven National Laboratory (BNL) is a new heavy ion-preinjector for relativistic heavy ion collider (RHIC) and NASA Space Radiation Laboratory (NSRL). Laser ion source (LIS) is a primary ion source provider for the BNL-EBIS. LIS with solenoid at the plasma drift section can realize the low peak current (˜100 μA) with high charge (˜10 nC) which is the BNL-EBIS requirement. The gap between two solenoids does not cause serious plasma current decay, which helps us to make up the BNL-EBIS beamline.

  1. Development of a permanent magnet alternative for a solenoidal ion source

    Martens, J.; Fahy, A.; Barr, M. [Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308 (Australia); Jardine, A.; Allison, W. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Dastoor, P.C., E-mail: Paul.Dastoor@newcastle.edu.au [Centre for Organic Electronics, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2014-12-01

    The most sensitive desktop-sized ionizer utilising electron bombardment is currently the solenoidal ion source. We present an alternate design for such an ion source whereby the solenoidal windings of the electromagnet are replaced by a shaped cylindrical permanent magnet in order to reduce the complexity and running costs of the instrument. Through finite element modelling of the magnetic field in COMSOL and experimental measurements on a small-scale prototype magnet stack, we demonstrate the required shape of the permanent magnet in order to generate the needed field, and the necessity of soft iron collars to smooth fluctuations along the central axis.

  2. Jefferson Lab CLAS12 Superconducting Solenoid magnet Requirements and Design Evolution

    Rajput-Ghoshal, Renuka [Jefferson Lab, Newport News, VA; Hogan, John P. [Jefferson Lab, Newport News, VA; Fair, Ruben J. [Jefferson Lab, Newport News, VA; Ghoshal, Probir K. [Jefferson Lab, Newport News, VA; Luongo, Cesar [Jefferson Lab, Newport News, VA; Elouadrhiri, Latifa [Jefferson Lab, Newport News, VA

    2014-12-01

    As part of the Jefferson Lab 12GeV accelerator upgrade project, one of the experimental halls (Hall B) requires two superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a toroidal configuration and the second is an actively shielded solenoidal magnet system consisting of 5 coils. In this presentation the physics requirements for the 5 T solenoid magnet, design constraints, conductor decision, and cooling choice will be discussed. The various design iterations to meet the specification will also be discussed in this presentation.

  3. Development of solenoid-induced helical wiggler with four poles per period

    Ohigashi, N; Kiyochi, M; Nakao, N; Fujita, M; Imasaki, K; Nakai, S; Mima, K

    1999-01-01

    A new type of helical wiggler consisting of two staggered-iron arrays inserted into a solenoid field has been developed. The field measured by a test wiggler showed linear increment with the period. It was seen that 24% of the solenoid field contributed to the induced wiggler field when the gap length and the period of the wiggler were 16 and 24 mm, respectively. This wiggler would be useful for an FEL with a low-energy electron beam propagating in a strong axial guiding field.

  4. ASME XI stroke time testing of solenoid valves at Connecticut Yankee Station

    Martin, C.W.

    1996-12-01

    Connecticut Yankee Atomic Power Company has developed the capability of measuring the stroke times of AC and DC solenoid valves. This allows the station to measure the stroke time of any solenoid valve in the plant, even those valves which do not have valve stem position indicators. Connecticut Yankee has adapted the ITI MOVATS Checkmate 3 system, using a signal input from a Bruel and Kjaer (B&K) Model 4382 acoustic accelerometer and the Schaumberg Campbell Associates (SCA) Model SCA-1148 dual sensor, which is a combined accelerometer and gaussmeter.

  5. Mach Number Dependence of Turbulent Magnetic Field Amplification: Solenoidal versus Compressive Flows

    Federrath, Christoph; Schober, Jennifer; Banerjee, Robi; Klessen, Ralf S; Schleicher, Dominik R G; 10.1103/PhysRevLett.107.114504

    2011-01-01

    We study the growth rate and saturation level of the turbulent dynamo in magnetohydrodynamical simulations of turbulence, driven with solenoidal (divergence-free) or compressive (curl-free) forcing. For models with Mach numbers ranging from 0.02 to 20, we find significantly different magnetic field geometries, amplification rates, and saturation levels, decreasing strongly at the transition from subsonic to supersonic flows, due to the development of shocks. Both extreme types of turbulent forcing drive the dynamo, but solenoidal forcing is more efficient, because it produces more vorticity.

  6. Design and Comparison of a 1 MW / 5s HTS SMES with Toroidal and Solenoidal Geometry

    Morandi, Antonio; Gholizad, Babak; Grilli, Francesco; Sirois, Frédéric; Zermeño, Víctor M R

    2015-01-01

    The design of a HTS SMES coil with solenoidal and toroidal geometry is carried out based on a commercially available 2G HTS conductor. A SMES system of practical interest (1 MW / 5 s) is considered. The comparison between ideal toroidal and solenoidal geometry is first discussed and the criteria used for choosing the geometrical parameters of the coils' bore are explained. The design of the real coil is then carried out and the final amount of conductor needed is compared. A preliminary comparison of the two coils in terms of AC loss during one charge discharge cycle is also discussed.

  7. Radiation-damping effects in a birdcage resonator with hyperpolarised 3He gas NMR at 1.5 T.

    Teh, Kevin; de Zanche, Nicola; Wild, Jim M

    2007-03-01

    The presence and diagnosis of radiation damping could have major implications in NMR experiments with hyperpolarised gases, where accurate knowledge of the flip angle is imperative. In this work radiation damping was observed and investigated in a low-pass birdcage resonator (Q=250) with samples of hyperpolarised 3He at 1.5 T. With an initially highly polarised (P=38%) sample of 3He in a spherical cell, the observed FID had a distorted line shape with a spectral line width that was three times that of the same sample in a virtually depolarised state (1 Hz line width for Pradiation damping. With highly polarised samples, significant radiation damping was observed and the effect was a lower than expected rate of depletion of M0 in RF flip angle calibration experiments, which led to significant underestimate of the RF flip angle. To our knowledge this is the first report of radiation damping in a birdcage resonator with samples hyperpolarised or otherwise. Experimental observation of radiation damping could be used as means of measuring coil efficiency as an alternative to the geometrical filling factor (eta) the definition of which is open to question for a birdcage resonator. Estimates of the birdcage filling factor from the measured damping time constants (eta(RD)=0.4%) are compared to those derived from electromagnetic energy ratios (eta(E)=1.6%) and metallic sphere frequency shift methods (eta(fs)=1.4%). These figures are much lower than the simple volume geometrical upper limit of eta(v)=3.7% derived from the ratio of cell volume to total coil volume (shield included). The physical explanation for this shortfall is that the bulk of the magnetic energy stored in the birdcage is spatially distributed predominantly between the rungs and the shield, and not in the coil centre where the sample is placed and where the B1+ field has its highest spatial homogeneity.

  8. Comparison of myocardial T1 and T2 values in 3 T with T2* in 1.5 T in patients with iron overload and controls.

    Camargo, Gabriel C; Rothstein, Tamara; Junqueira, Flavia P; Fernandes, Elsa; Greiser, Andreas; Strecker, Ralph; Pessoa, Viviani; Lima, Ronaldo S L; Gottlieb, Ilan

    2016-05-01

    Myocardial iron quantification remains limited to 1.5 T systems with T2* measurement. The present study aimed at comparing myocardial T2* values at 1.5 T to T1 and T2 mapping at 3.0 T in patients with iron overload and healthy controls. A total of 17 normal volunteers and seven patients with a history of myocardial iron overload were prospectively enrolled. Mid-interventricular septum T2*, native T1 and T2 times were quantified on the same day, using a multi-echo gradient-echo sequence at 1.5 T and T1 and T2 mapping sequences at 3.0 T, respectively. Subjects with myocardial iron overload (T2* iron overload quantification.

  9. Wave equations for pulse propagation

    Shore, B. W.

    1987-06-01

    Theoretical discussions of the propagation of pulses of laser radiation through atomic or molecular vapor rely on a number of traditional approximations for idealizing the radiation and the molecules, and for quantifying their mutual interaction by various equations of propagation (for the radiation) and excitation (for the molecules). In treating short-pulse phenomena it is essential to consider coherent excitation phenomena of the sort that is manifest in Rabi oscillations of atomic or molecular populations. Such processes are not adequately treated by rate equations for excitation nor by rate equations for radiation. As part of a more comprehensive treatment of the coupled equations that describe propagation of short pulses, this memo presents background discussion of the equations that describe the field. This memo discusses the origin, in Maxwell's equations, of the wave equation used in the description of pulse propagation. It notes the separation into lamellar and solenoidal (or longitudinal and transverse) and positive and negative frequency parts. It mentions the possibility of separating the polarization field into linear and nonlinear parts, in order to define a susceptibility or index of refraction and, from these, a phase and group velocity.

  10. Solenoid transport of a heavy ion beam for warm dense matterstudies and inertial confinement fusion

    Armijo, Julien

    2006-10-01

    From February to July 2006, I have been doing research as a guest at Lawrence Berkeley National Laboratory (LBNL), in the Heavy Ion Fusion group. This internship, which counts as one semester in my master's program in France, I was very pleased to do it in a field that I consider has the beauty of fundamental physics, and at the same time the special appeal of a quest for a long-term and environmentally-respectful energy source. During my stay at LBNL, I have been involved in three projects, all of them related to Neutralized Drift Compression Experiment (NDCX). The first one, experimental and analytical, has consisted in measuring the effects of the eddy currents induced by the pulsed magnets in the conducting plates of the source and diagnostic chambers of the Solenoid Transport Experiment (STX, which is a subset of NDCX). We have modeled the effect and run finite-element simulations that have reproduced the perturbation to the field. Then, we have modified WARP, the Particle-In-Cell code used to model the whole experiment, in order to import realistic fields including the eddy current effects and some details of each magnet. The second project has been to take part in a campaign of WARP simulations of the same experiment to understand the leakage of electrons that was observed in the experiment as a consequence to some diagnostics and the failure of the electrostatic electron trap. The simulations have shown qualitative agreement with the measured phenomena, but are still in progress. The third project, rather theoretical, has been related to the upcoming target experiment of a thin aluminum foil heated by a beam to the 1-eV range. At the beginning I helped by analyzing simulations of the hydrodynamic expansion and cooling of the heated material. But, progressively, my work turned into making estimates for the nature of the liquid/vapor two-phase flow. In particular, I have been working on criteria and models to predict the formation of droplets, their size

  11. Simulation research on dynamic and static performance of solenoid valve consider electromagnetic characteristics%考虑电磁特性的电磁开关阀动静态性能仿真研究

    孙建彬; 岑豫皖; 王刚

    2011-01-01

    为研究电磁特性下电磁阀的动静态性能,针对设计中使用到的电磁开关阀,首先分析了电磁铁的结构参数和电磁开关阀动力学模型,然后应用Ansoft Maxwell和AMESim建立了电磁开关阀仿真模型,对不同占空比以及不同频率下的脉宽调制(PWM)输入控制信号进行了仿真,分析了其动态响应过程及静态性能(空载流量、空载压力等),最后提出了提高电磁开关阀控制效率和控制精度的设计方法和思路,并进行了对比仿真验证.研究结果表明,该研究获得了较准确的电磁阀动静态性能仿真结果,提高了其控制效率和控制精度.%In order to research the dynamic and static performance of the solenoid valve consider electromagnetic characteristics, for the solenoid valve used in the design, the simulation model based on the application of AMESim and Ansoft Maxwell was established on the analysis of the structural parameters of solenoid and the dynamics of the solenoid valve. And pulse width modulation (PWM) input control signals were simulated under different duty cycle and frequency. Also the dynamic response and static performances such as no-load flow and deadhead pressure were analyzed. Finally, the design methods and ideas of improving the efficiency and control precision of solenoid valve were put forward,and the simulation validation was done. The research results show that the study obtains more precise dynamic and static performance simulation results of the solenoid valve,and improves the efficiency and control precision.

  12. Parallel transmit excitation at 1.5 T based on the minimization of a driving function for device heating

    Gudino, N., E-mail: natalia.gudino@nih.gov [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States); Sonmez, M.; Nielles-Vallespin, S.; Faranesh, A. Z.; Lederman, R. J.; Balaban, R. S.; Hansen, M. S. [National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892 (United States); Yao, Z.; Baig, T.; Martens, M. [Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106 (United States); Griswold, M. A. [Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106 and Department of Radiology, University Hospitals of Cleveland, Cleveland, Ohio 44106 (United States)

    2015-01-15

    Purpose: To provide a rapid method to reduce the radiofrequency (RF) E-field coupling and consequent heating in long conductors in an interventional MRI (iMRI) setup. Methods: A driving function for device heating (W) was defined as the integration of the E-field along the direction of the wire and calculated through a quasistatic approximation. Based on this function, the phases of four independently controlled transmit channels were dynamically changed in a 1.5 T MRI scanner. During the different excitation configurations, the RF induced heating in a nitinol wire immersed in a saline phantom was measured by fiber-optic temperature sensing. Additionally, a minimization of W as a function of phase and amplitude values of the different channels and constrained by the homogeneity of the RF excitation field (B{sub 1}) over a region of interest was proposed and its results tested on the benchtop. To analyze the validity of the proposed method, using a model of the array and phantom setup tested in the scanner, RF fields and SAR maps were calculated through finite-difference time-domain (FDTD) simulations. In addition to phantom experiments, RF induced heating of an active guidewire inserted in a swine was also evaluated. Results: In the phantom experiment, heating at the tip of the device was reduced by 92% when replacing the body coil by an optimized parallel transmit excitation with same nominal flip angle. In the benchtop, up to 90% heating reduction was measured when implementing the constrained minimization algorithm with the additional degree of freedom given by independent amplitude control. The computation of the optimum phase and amplitude values was executed in just 12 s using a standard CPU. The results of the FDTD simulations showed similar trend of the local SAR at the tip of the wire and measured temperature as well as to a quadratic function of W, confirming the validity of the quasistatic approach for the presented problem at 64 MHz. Imaging and heating reduction of the guidewire were successfully performed in vivo with the proposed hardware and phase control. Conclusions: Phantom and in vivo data demonstrated that additional degrees of freedom in a parallel transmission system can be used to control RF induced heating in long conductors. A novel constrained optimization approach to reduce device heating was also presented that can be run in just few seconds and therefore could be added to an iMRI protocol to improve RF safety.

  13. Simulation and experimental control of a 3-RPR parallel robot using optimal fuzzy controller and fast on/off solenoid valves based on the PWM wave.

    Moezi, Seyed Alireza; Rafeeyan, Mansour; Zakeri, Ehsan; Zare, Amin

    2016-03-01

    In this paper, a robust optimal fuzzy controller based on the Pulse Width Modulation (PWM) technique is proposed to control a laboratory parallel robot using inexpensive on/off solenoid valves. The controller coefficients are determined using Modified Cuckoo Optimization Algorithm. The objective function of this method is considered such that the results show the position tracking by the robot with less force and more efficiency. Regarding the results of experimental tests, the control strategy with on/off valves indicates good performance such that the maximum value of RMS of error for a circular path with increasing force on the system is 3.1mm. Furthermore, the results show the superiority of the optimal fuzzy controller compared with optimal PID controller in tracking paths with different conditions and uncertainties.

  14. Concept of a Staged FEL Enabled by Fast Synchrotron Radiation Cooling of Laser-Plasma Accelerated Beam by Solenoidal Magnetic Fields in Plasma Bubble

    Seryi, Andrei; Andreev, Alexander; Konoplev, Ivan

    2016-01-01

    A novel method for generating GigaGauss solenoidal field in laser-plasma bubble, using screw-shaped laser pulses, has been recently presented in arXiv:1604.01259 [physics.plasm-ph]. Such magnetic fields enable fast synchrotron radiation cooling of the beam emittance of laser-plasma accelerated leptons. This recent finding opens a novel approach for design of laser-plasma FELs or colliders, where the acceleration stages are interleaved with laser-plasma emittance cooling stages. In this concept paper we present an outline of how a staged plasma-acceleration FEL could look like and discuss further studies needed to investigate the feasibility of the concept in detail.

  15. Impact of detector solenoid on the Compact Linear Collider luminosity performance

    Inntjore Levinsen, Y.; Dalena, B.; Tomás, R.; Schulte, D.

    2014-05-01

    In order to obtain the necessary luminosity with a reasonable amount of beam power, the Compact LInear Collider (CLIC) design includes an unprecedented collision beam size of σy=1 nm vertically and σx=45 nm horizontally. With exceptionally small and flat beams, the luminosity can be significantly degraded due to the combination of the experimental solenoid field and a large crossing angle. The two main effects reducing the luminosity are y-x'-coupling and an increase of vertical dispersion. Additionally, incoherent synchrotron radiation (ISR) from the orbit deflection created by the solenoid field increases the beam emittance and results in unrecoverable luminosity degradation. A novel approach to evaluate the ISR effect from a realistic solenoid field without knowledge of the full compensation of the geometric aberrations is presented. This approach is confirmed by a detailed study of the correction techniques to compensate the beam optics distortions. The unrecoverable luminosity loss due to ISR for CLIC at 3 TeV has been evaluated, and found to be around 4% to 5% for the solenoid design under study.

  16. On-surface integration and test of the ATLAS central solenoid and its proximity cryogenics

    Ruber, Roger J M Y; Cipolla, G; Deront, L; Doi, Y; Haruyama, T; Haug, F; Kanahara, T; Kawai, M; Kondo, T; Kondo, Y; Kopeykin, N; Mizumaki, S; Metselaar, J; Park, A; Pavlov, O V; Pezzetti, M; Pirotte, O; Ravat, S; Sbrissa, E; Stepanov, V; ten Kate, H H J; Yamamoto, A

    2004-01-01

    The ATLAS detector for the LHC at CERN requires a superconducting solenoid, which provides the magnetic field for the inner detector. The ATLAS Central Solenoid and its associated proximity cryogenics system has been designed by KEK in collaboration with CERN. Following construction and preliminary tests at Toshiba in Japan the equipment has been shipped to CERN. The system is being prepared for the integration in the common cryostat with the LAr calorimeter, whereafter a full on-surface test has to be completed before its final installation 100 m underground in the ATLAS cavern. For this purpose a provisional set-up for commissioning of the final proximity cryogenics, the connecting chimney and the solenoid has been established. A number of tests and simulations have been conducted in applying a new process control system to validate the cryogenics functionalities, the electrical powering scheme as well as the magnet control and safety systems. The present status of the solenoid project and the results of th...

  17. Compact Muon Solenoid: largest physics experiment to be held in 2007

    Atkins, William

    2007-01-01

    "over the last fifteen years about 2'300 engineers and scientists from over 150 scientific institutions in 37 countries around the world have worked together to design and build a gigantic general-purpose particle detector, what is called the Compact Muon Solenoid (CMS)." (1 page)

  18. The Magnetic Field inside a Long Solenoid--A New Approach

    Andrews, David; Carlton, Kevin; Lisgarten, David

    2010-01-01

    This article describes a technique for measuring the magnetic field inside a long solenoid using computer data logging. This is a new approach to a standard student practical. The design and construction of the sensors is described; they significantly reduce the cost of the apparatus. The approach of the practical is for the students to…

  19. Nonlinear Dynamic Model-Based Adaptive Control of a Solenoid-Valve System

    DongBin Lee

    2012-01-01

    Full Text Available In this paper, a nonlinear model-based adaptive control approach is proposed for a solenoid-valve system. The challenge is that solenoids and butterfly valves have uncertainties in multiple parameters in the nonlinear model; various kinds of physical appearance such as size and stroke, dynamic parameters including inertia, damping, and torque coefficients, and operational parameters especially, pipe diameters and flow velocities. These uncertainties are making the system not only difficult to adjust to the environment, but also further complicated to develop the appropriate control approach for meeting the system objectives. The main contribution of this research is the application of adaptive control theory and Lyapunov-type stability approach to design a controller for a dynamic model of the solenoid-valve system in the presence of those uncertainties. The control objectives such as set-point regulation, parameter compensation, and stability are supposed to be simultaneously accomplished. The error signals are first formulated based on the nonlinear dynamic models and then the control input is developed using the Lyapunov stability-type analysis to obtain the error bounded while overcoming the uncertainties. The parameter groups are updated by adaptation laws using a projection algorithm. Numerical simulation results are shown to demonstrate good performance of the proposed nonlinear model-based adaptive approach and to compare the performance of the same solenoid-valve system with a non-adaptive method as well.

  20. TESTING OF FRAMED STRUCTURE PARTS OF COMPACT MUON SOLENOID BY NONDESTRUCTIVE METHOD

    L. Larchenkov

    2013-01-01

    Full Text Available Suspension parts of a compact muon solenoid for Large Hadron Collider have been tested in the paper. The paper describes a steady-state and cyclic “tension-compression” load created by superconducting electromagnet with energy of 3 GJ and magnetic induction of 4 tesla. A nondestructive testing method has been applied in the paper.

  1. Rotation of the solenoid magnet of the CMS experiment before the insertion into its cryostat

    Patrice Loiez

    2005-01-01

    At one side of the 27 km ring of the future Large Hadron Collider (LHC), the 230 tonne solenoid magnet for the CMS experiment has been rotated through 90° prior to insertion into its cryostat - the jacket that will cool the magnet to 4.2 K (-269° C).

  2. Over Voltage in a Multi-sectioned Solenoid during a Quenching

    Guo, Xinglong; Wang, Li; Pan, Heng; Wu, Hong; Liu, Xiaokun; Chen, Anbin; Green, M.A.; Xu, F.Y.

    2009-06-21

    Accurate analysis of over voltage in the superconducting solenoid during a quench is one of the bases for quench protection system design. Classical quench simulation methods can only give rough estimation of the over voltage within a magnet coil. In this paper, for multi-sectioned superconducting solenoid, based on the classical assumption of ellipsoidal normal zone, three-dimension al temperature results are mapped to the one-dimension of the wire, the temperature distribution along the wire and the resistances of each turn are obtained. The coil is treated as circuit comprised of turn resistances, turn self and mutual inductances. The turn resistive voltage, turn inductive voltage, and turn resultant voltage along the wire are calculated. As a result, maximum internal voltages, the layer-to-layer voltages and the turn-to-turn voltages are better estimated. Utilizing this method, the over voltage of a small solenoid and a large solenoid during quenching have been studied. The result shows that this method can well improve the over voltage estimate, especially when the coil is larger.

  3. Superficial amygdala and hippocampal activity during affective music listening observed at 3 T but not 1.5 T fMRI.

    Skouras, Stavros; Gray, Marcus; Critchley, Hugo; Koelsch, Stefan

    2014-11-01

    The purpose of this study was to compare 3 T and 1.5 T fMRI results during emotional music listening. Stimuli comprised of psychoacoustically balanced instrumental musical pieces, with three different affective expressions (fear, neutral, joy). Participants (N=32) were split into two groups, one subjected to fMRI scanning using 3 T and another group scanned using 1.5 T. Whole brain t-tests (corrected for multiple comparisons) compared joy and fear in each of the two groups. The 3 T group showed significant activity differences between joy and fear localized in bilateral superficial amygdala, bilateral hippocampus and bilateral auditory cortex. The 1.5 T group showed significant activity differences between joy and fear localized in bilateral auditory cortex and cuneus. This is the first study to compare results obtained under different field strengths with regard to affective processes elicited by means of auditory/musical stimulation. The findings raise concern over false negatives in the superficial amygdala and hippocampus in affective studies conducted under 1.5 T and caution that imaging improvements due to increasing magnetic field strength can be influenced by region-specific characteristics.

  4. ANALYSIS OF THE MAGNETIC FIELD MEASURED BY A ROTATING HALL PROBE IN A SOLENOID TO LOCATE ITS MAGNETIC AXIS.

    KPONOU,A.; PIKIN,A.; BEEBE,E.; ALESSI,J.

    2000-11-06

    We have analyzed the motion of a Hall probe, which is rotated about an axis that is arbitrarily displaced and oriented with respect to the magnetic axis of a solenoid. We outline how the magnetic field measured by the rotating Hall probe can be calculated. We show how to compare theoretical results with actual measurements, to determine the displacement and orientation of the axis of rotation of the probe from the magnetic axis. If the center of rotation of the probe is known by surveying, the corresponding point on the magnetic axis of the solenoid can be located. This is applied to a solenoid that was built for BNL by Oxford Instruments.

  5. Design, fabrication, and characterization of a solenoid system to generate magnetic field for an ECR proton source

    S K Jain; P A Naik; P R Hannurkar

    2010-08-01

    Solenoid coils with iron jacket (electromagnets) have been designed and developed for generation and confinement of the plasma produced by an electron cyclotron resonance source operating at 2450 MHz frequency. The magnetic field configurations designed using the solenoid coils are off-resonance, mirror, and flat, satisfying electron cyclotron resonance condition along the axis of the plasma chamber. 2D Poisson software was used for designing. Details of design, fabrication, and magnetic field mapping of the solenoid coils are presented in this paper.

  6. Explicit Representation of Roots on -Adic Solenoids and Non-Uniqueness of Embeddability into Rational One-Parameter Subgroups

    Peter Becker-Kern

    2007-11-01

    This note generalizes known results concerning the existence of roots and embedding one-parameter subgroups on -adic solenoids. An explicit representation of the roots leads to the construction of two distinct rational embedding one-parameter subgroups. The results contribute to enlighten the group structure of solenoids and to point out difficulties arising in the context of the embedding problem in probability theory. As a consequence, the uniqueness of embedding of infinitely divisible probability measures on -adic solenoids is solved under a certain natural condition.

  7. SU-E-QI-19: Evaluation of a Clinical 1.5T MRI for Prostate Cancer MRS Imaging Using a In Vivo Tumor Model

    Chen, X; Chen, L; Hensley, H; Cvetkovic, D; Fan, J; Ma, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Zhang, C [Fox Chase Cancer Center, Philadelphia, PA (United States); Qiqihaer Medical University, Qiqihaer, Heilongjiang (China)

    2014-06-15

    Purpose: Magnetic resonance spectroscopic (MRS) imaging may provide important bio-markers to distinguish normal/cancerous prostate tissue. While MRS imaging requires a high uniform magnetic field, the ability of a clinical 1.5T MRI to achieve a comparable MRS signal is of interest for radiation treatment planning/assessment. This study is to evaluate the MRS imaging of a 1.5T clinical MRI for prostate cancers by comparing with a small animal 7T MRS scanner. Methods: A tumor model was developed by implanting LNCaP tumor cells in nude mice prostates. Tumor was monitored 3 weeks after implantation using MRI, and MRS imaging was performed on the tumor area when the tumor reached around 1cm in diameter. The 1.5T GE clinical MR scanner and the 7T Bruker small animal MR scanner were used for each mouse. MR spectrums acquired with these scanners were analyzed and compared. The signals of Choline and Citrate were considered. Results: The prostate tumor MR spectrum under the 1.5T clinical MRI showed a similar spectrum pattern to that acquired using the 7T animal MRI. The Choline signal (3.2ppm) is clear and there is no clear peak for Citrate (2.6ppm). However, the signal magnitude for Choline is not dominant compared to the background signal under 1.5T MRI. Typical cancerous prostate tissue MR spectrum with an increased Choline signal and a reduced Citrate signal was observed. In addition, signal variation is noticeable between repeated spectrum scans. The average of these scans showed a comparable and consistent spectrum to those under 7T MRI. Conclusion: The clinical 1.5T MRI is able to acquire a MR spectrum for prostate cancer comparable to those acquired using a dedicated 7T MRS scanner. However, to achieve a consistent and reliable spectrum, multiple repeated scans were necessary to get a statistical result and reduce the noise-induced artifact. This work was supported in part by the National Cancer Institute Grant R21 CA131979 and R01CA172638.

  8. Wave equations for pulse propagation

    Shore, B.W.

    1987-06-24

    Theoretical discussions of the propagation of pulses of laser radiation through atomic or molecular vapor rely on a number of traditional approximations for idealizing the radiation and the molecules, and for quantifying their mutual interaction by various equations of propagation (for the radiation) and excitation (for the molecules). In treating short-pulse phenomena it is essential to consider coherent excitation phenomena of the sort that is manifest in Rabi oscillations of atomic or molecular populations. Such processes are not adequately treated by rate equations for excitation nor by rate equations for radiation. As part of a more comprehensive treatment of the coupled equations that describe propagation of short pulses, this memo presents background discussion of the equations that describe the field. This memo discusses the origin, in Maxwell's equations, of the wave equation used in the description of pulse propagation. It notes the separation into lamellar and solenoidal (or longitudinal and transverse) and positive and negative frequency parts. It mentions the possibility of separating the polarization field into linear and nonlinear parts, in order to define a susceptibility or index of refraction and, from these, a phase and group velocity. The memo discusses various ways of characterizing the polarization characteristics of plane waves, that is, of parameterizing a transverse unit vector, such as the Jones vector, the Stokes vector, and the Poincare sphere. It discusses the connection between macroscopically defined quantities, such as the intensity or, more generally, the Stokes parameters, and microscopic field amplitudes. The material presented here is a portion of a more extensive treatment of propagation to be presented separately. The equations presented here have been described in various books and articles. They are collected here as a summary and review of theory needed when treating pulse propagation.

  9. Modeling hemodynamic responses in auditory cortex at 1.5 T using variable duration imaging acoustic noise.

    Hu, Shuowen; Olulade, Olumide; Castillo, Javier Gonzalez; Santos, Joseph; Kim, Sungeun; Tamer, Gregory G; Luh, Wen-Ming; Talavage, Thomas M

    2010-02-15

    A confound for functional magnetic resonance imaging (fMRI), especially for auditory studies, is the presence of imaging acoustic noise generated mainly as a byproduct of rapid gradient switching during volume acquisition and, to a lesser extent, the radiofrequency transmit. This work utilized a novel pulse sequence to present actual imaging acoustic noise for characterization of the induced hemodynamic responses and assessment of linearity in the primary auditory cortex with respect to noise duration. Results show that responses to brief duration (46 ms) imaging acoustic noise is highly nonlinear while responses to longer duration (>1 s) imaging acoustic noise becomes approximately linear, with the right primary auditory cortex exhibiting a higher degree of nonlinearity than the left for the investigated noise durations. This study also assessed the spatial extent of activation induced by imaging acoustic noise, showing that the use of modeled responses (specific to imaging acoustic noise) as the reference waveform revealed additional activations in the auditory cortex not observed with a canonical gamma variate reference waveform, suggesting an improvement in detection sensitivity for imaging acoustic noise-induced activity. Longer duration (1.5 s) imaging acoustic noise was observed to induce activity that expanded outwards from Heschl's gyrus to cover the superior temporal gyrus as well as parts of the middle temporal gyrus and insula, potentially affecting higher level acoustic processing.

  10. Safety of implantable coronary stents during 1H-magnetic resonance imaging at 1.0 and 1.5 T.

    Strohm, O; Kivelitz, D; Gross, W; Schulz-Menger, J; Liu, X; Hamm, B; Dietz, R; Friedrich, M G

    1999-01-01

    The safety of most available implantable intracoronary stents during magnetic resonance imaging (MRI) has not been sufficiently tested. Minor, but possibly clinically significant, increases in temperature have not been excluded. We measured temperature changes of 14 different stents clinically in use or currently tested for release on the world market. Stents were examined in 1.0- and 1.5-T MR scanners with multiple sequences used in routine cardiac and thoracic MRI examinations ("clinical worst case") and after implantation of the stents into the coronary arteries of excised pig hearts (1.5-T scanner only). We used a highly sensitive infrared camera with a thermal resolution of 10 mK and did not see significant heating of any stent during the examinations. We conclude that MRI is safe in patients with the currently available intracoronary stents.

  11. Diffusion-weighted MR neurography of the brachial and lumbosacral plexus: 3.0 T versus 1.5 T imaging

    Mürtz, P., E-mail: petra.muertz@ukb.uni-bonn.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Kaschner, M., E-mail: Marius.Kaschner@med.uni-duesseldorf.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Lakghomi, A., E-mail: Asadeh.Lakghomi@ukb.uni-bonn.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Gieseke, J., E-mail: juergen.gieseke@ukb.uni-bonn.de [Philips Healthcare, Lübeckertordamm 5, 20099 Hamburg (Germany); Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Willinek, W.A., E-mail: winfried.willinek@ukb.uni-bonn.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Schild, H.H., E-mail: hans.schild@ukb.uni-bonn.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany); Thomas, D., E-mail: daniel.thomas@ukb.uni-bonn.de [Department of Radiology, University of Bonn, Sigmund-Freud-Straße 25, 53105 Bonn (Germany)

    2015-04-15

    Highlights: •DW MRN of brachial and lumbosacral plexus at 1.5 T and at 3.0 T was compared. •For lumbosacral plexus, nerve conspicuity on MIP images was superior at 3.0 T, also visible length and mean sharpness of the nerves. •For brachial plexus, nerve conspicuity at 3.0 T was rather inferior, nerve length was not significantly different, mean sharpness was superior at 3.0 T. -- Abstract: Purpose: To compare intraindividually the nerve conspicuity of the brachial and lumbosacral plexus on diffusion-weighted (DW) MR neurography (MRN) at two different field strengths. Materials and methods: 16 healthy volunteers were investigated at 3.0 T and 1.5 T applying optimized variants of a DW spin-echo echo-planar imaging sequence with short TI inversion recovery fat suppression. Full-volume (FV) and curved sub-volume (CSV) maximum intensity projection (MIP) images were reconstructed and nerve conspicuity was visually assessed. Moreover, visible length and sharpness of the nerves were quantitatively analyzed. Results: On FV MIP images, nerve conspicuity at 3.0 T compared to 1.5 T was worse for brachial plexus (P = 0.00228), but better for lumbosacral plexus (P = 0.00666). On CSV MIP images, nerve conspicuity did not differ significantly for brachial plexus, but was better at 3.0 T for lumbosacral plexus (P = 0.00091). The visible length of the analyzed nerves did not differ significantly with the exception of some lumbosacral nerves, which were significantly longer at 3.0 T. The sharpness of all investigated nerves was significantly higher at 3.0 T by about 40–60% for cervical and 97–169% for lumbosacral nerves. Conclusion: DW MRN imaging at 3.0 T compared to 1.5 T is superior for lumbosacral plexus, but not for brachial plexus.

  12. [Evaluation of Artificial Hip Joint with Radiofrequency Heating Issues during MRI Examination: A Comparison between 1.5 T and 3 T].

    Yamazaki, Masaru; Ideta, Takahiro; Kudo, Sadahiro; Nakazawa, Masami

    2016-06-01

    In magnetic resonance imaging (MRI), when radiofrequency (RF) is irradiated to a subject with metallic implant, it can generate heat by RF irradiation. Recently 3 T MRI scanner has spread widely and imaging for any regions of whole body has been conducted. However specific absorption rate (SAR) of 3 T MRI becomes approximately four times as much as the 1.5 T, which can significantly affect the heat generation of metallic implants. So, we evaluated RF heating of artificial hip joints in different shapes and materials in 1.5 T and 3 T MRI. Three types of artificial hip joints made of stainless alloy, titanium alloy and cobalt chrome alloy were embedded in the human body-equivalent phantom respectively and their temperature change were measured for twenty minutes by 1.5 T and 3 T MRI. The maximum temperature rise was observed at the bottom head in all of three types of artificial hip joints, the rise being 12°C for stainless alloy, 11.9°C for titanium alloy and 6.1°C for cobalt chrome alloy in 1.5 T. The temperature rise depended on SAR and the increase of SAR had a good linear relationship with the temperature rise. It was found from the result that the RF heating of metallic implants can take place in various kinds of material and the increase of SAR has a good linear relationship with the temperature rise. This experience shows that reduction of SAR can decrease temperature of metallic implants.

  13. 3D proton MR spectroscopic imaging of prostate cancer using a standard spine coil at 1.5 T in clinical routine: a feasibility study

    Lichy, Matthias P.; Pintaske, Joerg; Machann, Juergen; Schick, Fritz [Eberhard-Karls University Tuebingen, Department of Radiologic Diagnostics, Tuebingen (Germany); Eberhard-Karls University Tuebingen, Section on Experimental Radiology, Tuebingen (Germany); Kottke, Raimund; Diergarten, Till; Claussen, Claus D.; Schlemmer, Heinz-Peter [Eberhard-Karls University Tuebingen, Department of Radiologic Diagnostics, Tuebingen (Germany); Anastasiadis, Aristotelis; Hennenlotter, Joerg; Stenzl, Arnulf [Eberhard-Karls University Tuebingen, Department of Urology, Tubingen (Germany); Roell, Stefan [Siemens AG, Medical Solutions MR Application Development, Spectroscopy (MREA-MRS), Erlangen (Germany)

    2005-04-01

    The objective of this study was to demonstrate the feasibility of 3D proton MR spectroscopic imaging (MRSI) of the prostate using a standard spine instead of a dedicated endorectal coil at 1.5 T. Twenty-eight patients (25 with biopsy proven prostate cancers and three patients with a benign prostate hyperplasia) were examined. MRI and MRSI were conducted with commercial array surface coils at 1.5 T. Ratios of choline (Cho), creatine (Cr) and citrate (Ci) were calculated for tumour, central and peripheral zone retrospectively, based on axial T2 weighed MR images and histology reports. Prostate cancer was characterized by significantly elevated (Cho+Cr)/Ci ratio compared with non-tumourous prostate tissue. The quality of all proton MR spectra was considered to be good or acceptable in 17/28 patients (61%) and poor in 11/28 (39%) examinations. In 20/25 patients with proven malignancy (80%), MRSI was considered to be helpful for the detection of prostate cancer. In 4/25 patients with proven malignancy (16%) who underwent seed implantation, radiotherapy or hormone deprivation before MR examination spectroscopy was of poor and non-diagnostic quality. MRSI of the prostate is feasible within clinical routine using the spine array surface coil at 1.5 T. It can consequently be applied to patients even with contraindications for endorectal coils. However, spectral quality and signal-to-noise ratio is clearly inferior to 3D MRSI examinations with endorectal coils. (orig.)

  14. Aberrations due to solenoid focusing of a multiply charged high-current ion beam

    Grégoire, G; Lisi, N; Schnuriger, J C; Scrivens, R; Tambini, J

    2000-01-01

    At the output of a laser ion source, a high current of highly charged ions with a large range of charge states is available. The focusing of such a beam by magnetic elements causes a nonlinear space-charge field to develop which can induce large aberrations and emittance growth in the beam. Simulation of the beam from the CERN laser ion source will be presented for an ideal magnetic and electrostatic system using a radially symmetric model. In addition, the three dimensional software KOBRA3 is used for the simulation of the solenoid line. The results of these simulations will be compared with experiments performed on the CERN laser ion source with solenoids (resulting in a hollow beam) and a series of gridded electrostatic lenses. (5 refs).

  15. Spin flipping a stored vertically polarized proton beam with an RF solenoid

    Phelps, R. A.; Blinov, B. B.; Chu, C. M.; Courant, E. D.; Crandell, D. A.; Kaufman, W. A.; Krisch, A. D.; Nurushev, T. S.; Ratner, L. G.; Wong, V. K.; Caussyn, D. D.; Derbenev, Ya. S.; Ellison, T. J. P.; Lee, S. Y.; Rinckel, T.; Schwandt, P.; Sperisen, F.; Stephenson, E. J.; Przewoski, B. von; Ohmori, C.

    1995-09-01

    A recent experiment in the IUCF cooler ring studied the spin flip of a stored vertically polarized 139 MeV proton beam. This spin flip was accomplished by using an RF solenoid to induce an artificial depolarizing resonance in the ring, and then varying the solenoid's frequency through this resonance value to induce spin flip. We found a polarization loss after multiple spin flips of about 0.00±0.05% per flip and also losses for very long flip times. This device will be useful for reducing systematic errors in polarized beam-internal target scattering asymmetry experiments by enabling experimenters to perform frequent beam polarization reversals in the course of the experiment.

  16. Beam Dynamics Based Design of Solenoid Channel for TAC Proton Linac

    Kisoglu, H F

    2014-01-01

    Today a linear particle accelerator (linac), in which electric and magnetic fields are of vital importance, is one of the popular energy generation sources like Accelerator Driven System (ADS). A multipurpose, including primarily ADS, proton linac with energy of ~2 GeV is planned to constitute within the Turkish Accelerator Center (TAC) project collaborated by more than 10 Turkish universities. A Low Energy Beam Transport (LEBT) channel with two solenoids is a subcomponent of this linac. It transports the proton beam ejected by an ion source, and matches it with the Radio Frequency Quadrupole (RFQ) that is an important part of the linac. The LEBT channel would be consisted of two focusing solenoids and some diagnostic elements such as faraday cup, BC transformers, etc. This paper includes a beam dynamical design and optimization study of LEBT channel for TAC proton linac done by using a beam dynamics simulation code PATH MANAGER and comparing of the simulation results with the theoretical expectations.

  17. Construction of the Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) at Notre Dame

    Allen, Jacob; Bardayan, Dan; Blankstein, Drew; Hall, Matthew; Hall, Oscar; Kolata, James; O'Malley, Patrick; Becchetti, Frederick; Blackmon, Jeffery; Pain, Steven

    2016-09-01

    The study of nucleon transfer reactions gives information about many nuclei involved in astrophysical processes. The design and use of new detector systems improves our ability to accurately characterize these nuclei. The Solenoid Spectrometer for Nuclear AstroPhysics (SSNAP) is a new helical orbit spectrometer being designed at the University of Notre Dame to study transfer reactions with high-energy light ion beams from the FN tandem accelerator. SSNAP incorporates a series of position-sensitive silicon detectors to be set on-axis inside the second TwinSol solenoid. SSNAP will be sensitive to light ions produced in different reactions and the charged-particle decay products from the exotic nuclei produced. Results of initial testing and future plans with this detector system will be shown in this presentation. This work is supported by the National Science Foundation and the Joint Institute for Nuclear Astrophysics.

  18. High luminosity interaction region design for collisions inside high field detector solenoid

    Milardi, Catia; Raimondi, Pantaleo; Sgamma, Francesco

    2011-01-01

    An innovatory interaction region has been recently conceived and realized on the Frascati DA{\\Phi}NE lepton collider. The concept of tight focusing and small crossing angle adopted to achieve high luminosity in multibunch collisions has evolved towards enhanced beam focusing at the interaction point with large horizontal crossing angle, thanks to a new compensation mechanism for the beam-beam resonances. The novel configuration has been tested with a small detector without solenoidal field yielding a remarkable improvement in terms of peak as well as integrated luminosity. The high luminosity interaction region has now been modified to host a large detector with a strong solenoidal field which significantly perturbs the beam optics introducing new design challenges in terms of interaction region optics design, beam transverse coupling control and beam stay clear requirements. Interaction region design criteria as well as the luminosity results relevant to the structure test are presented and discussed.

  19. Circularly Inclined Solenoid Channel for 6D Ionization Cooling of Muons

    Alexahin, Y.; /Fermilab

    2009-05-01

    Ionization cooling is essential for realization of Muon Collider, muons beam based neutrino factories and other experiments involving muons. The simplest structure - absorber(s) immersed in alternating solenoidal magnetic field - provides only transverse cooling since the longitudinal motion in the most suitable momentum range (2-300MeV/c) is naturally anti-damped. To overcome this difficulty it is proposed to periodically tilt solenoids so that a rotating transverse magnetic field was created. By choosing the phase advance per period above a multiple of 2{pi} it is possible to ensure that muons with higher momentum make a longer path in the absorber (whether distributed or localized) thus providing longitudinal damping. Basic theory of such channel and results of tracking simulations are presented.

  20. Magnetic Field, Force, and Inductance Computations for an Axially Symmetric Solenoid

    Lane, John E.; Youngquist, Robert C.; Immer, Christopher D.; Simpson, James C.

    2001-01-01

    The pumping of liquid oxygen (LOX) by magnetic fields (B field), using an array of electromagnets, is a current topic of research and development at Kennedy Space Center, FL. Oxygen is paramagnetic so that LOX, like a ferrofluid, can be forced in the direction of a B field gradient. It is well known that liquid oxygen has a sufficient magnetic susceptibility that a strong magnetic gradient can lift it in the earth's gravitational field. It has been proposed that this phenomenon can be utilized in transporting (i.e., pumping) LOX not only on earth, but on Mars and in the weightlessness of space. In order to design and evaluate such a magnetic pumping system, it is essential to compute the magnetic and force fields, as well as inductance, of various types of electromagnets (solenoids). In this application, it is assumed that the solenoids are air wrapped, and that the current is essentially time independent.

  1. Effect Of The LEBT Solenoid Magnetic Field On The Beam Generation For Particle Tracking

    Yarmohammadi Satri, M; CERN. Geneva. ATS Department

    2013-01-01

    Linac4 is a 160 MeV H- linear accelerator which will replace the 50 MeV proton Linac2 for upgrade of the LHC injectors with higher intensity and eventually an increase of the LHC luminosity. Linac4 structure is a source, a 45 keV low energy beam transport line (LEBT) with two solenoids, a 3 MeV Radiofrequency Quadrupole (RFQ), a Medium Energy Beam Transport line (MEBT), a 50 Mev DTL, a 100 Mev CCDTL and PIMS up to 160 Mev. We use Travel v4.07 and PathManager code for simulation. Firstly, we need to a file as a source and defining the beginning point (last point in tracking back) of simulation. We recognise the starting point base on the solenoid magnetic property of LEBT.

  2. Study of thermosiphon cooling scheme for the production solenoid of the Mu2e experiment at Fermilab

    Dhanaraj, N.; Kashikhin, V.; Peterson, T.; Pronskikh, V.; Nicol, T.

    2014-01-01

    A thermosiphon cooling scheme is envisioned for the Production Solenoid of the Mu2e experiment at Fermi National Accelerator Laboratory. The thermosiphon cooling is achieved by indirect cooling with helium at 4.7 K. The siphon tubes are welded to the solenoid outer structure. The anticipated heat loads in the solenoid is presented as well as the cooling scheme design. A thermal model using ANSYS to simulate the temperature gradient is presented. The thermal analysis also makes provisions for including the heat load generated in the coils and structures by the secondary radiation simulated using the MARS 15 code. The impact of the heat loads from supports on the solenoid cooling is studied. The thermosiphon cooling scheme is also validated using pertinent correlations to study flow reversals and the cooling regime.

  3. Optimal Design on the Magnetic Field of the High-speed Response Solenoid Valve

    2002-01-01

    As an integrated control unit that directly transfo rm s digital electric signals into analogy hydraulic signals, High-speed response solenoid valve (HSV) plays an important role in determining an electro-hydrauli c automatic system's overall performance. In the process of designing an HSV, o ne should well understand that various soft magnetic material properties and geo metries greatly affect HSV's magnetic field design that accordingly has a direc t influence on HSV's electric performance. As an approac...

  4. View through the CMS detector during the cooldown of the solenoid on February 2006

    Richard Breedon, UC Davis

    2006-01-01

    Image looking along the beam direction through CMS. One can see, from the inside out: the patch panels and cables for the Preshower and ECAL; the front of the endcap HCAL; some cathode strip chambers (CSCs) for detecting muons; the sealed solenoid (the first circular silver-coloured ring) currently being cooled to operating temperature and held by the central barrel yoke ring (red and orange); one of the other barrel yoke rings installed with many muon chambers (silver rectangular boxes).

  5. Towards maintenance-free SOVs (solenoid operated valves). [For nuclear power plant use

    Rustagi, R. (Valcor Engineering Corp., Springfield, NJ (USA))

    1991-05-01

    Because most solenoid operated valves (SOVs) are being used in vital safety related systems in nuclear power plants, they must be shown to perform satisfactorily over 40 years of normal service plus one year into post-LOCA. Current practice in SOV design and manufacture, as described here, aims to minimize the need for maintenance and to make it simpler when it is necessary. (author).

  6. Finite Element Analysis on the Pre-load Structures of the Central Solenoid for the HT-7U Device

    2001-01-01

    The central solenoid is an important part of the HT-7U device. In this paper, the computational analysis of the stress and the displacement on the pre-load structures of the central solenoid have been made by the finite element analysis system COSMOS/M2.0 under room and/or operating temperature. According to the analytical results, the clip aprons and compression plates are all satisfied with safety design criteria.

  7. Evaluation and Compensation of Detector Solenoid Effects on Disrupted Beam in the ILC 14 mrad Extraction Line

    Toprek, Dragan; /VINCA Inst. Nucl. Sci., Belgrade; Nosochkov, Yuri; /SLAC

    2008-12-18

    This paper presents calculations of detector solenoid effects on disrupted primary beam in the ILC 14 mrad extraction line. Particle tracking simulations are performed for evaluation of primary beam loss along the line as well as of beam distribution and polarization at Compton Interaction Point. The calculations are done both without and with solenoid compensation. The results are obtained for the baseline ILC energy of 500 GeV center-of-mass and three options of beam parameters.

  8. A solenoidal synthetic field and the non-Abelian Aharonov-Bohm effects in neutral atoms

    Huo, Ming-Xia; Nie, Wei; Hutchinson, David A. W.; Kwek, Leong Chuan

    2014-08-01

    Cold neutral atoms provide a versatile and controllable platform for emulating various quantum systems. Despite efforts to develop artificial gauge fields in these systems, realizing a unique ideal-solenoid-shaped magnetic field within the quantum domain in any real-world physical system remains elusive. Here we propose a scheme to generate a ``hairline'' solenoid with an extremely small size around 1 micrometer which is smaller than the typical coherence length in cold atoms. Correspondingly, interference effects will play a role in transport. Despite the small size, the magnetic flux imposed on the atoms is very large thanks to the very strong field generated inside the solenoid. By arranging different sets of Laguerre-Gauss (LG) lasers, the generation of Abelian and non-Abelian SU(2) lattice gauge fields is proposed for neutral atoms in ring- and square-shaped optical lattices. As an application, interference patterns of the magnetic type-I Aharonov-Bohm (AB) effect are obtained by evolving atoms along a circle over several tens of lattice cells. During the evolution, the quantum coherence is maintained and the atoms are exposed to a large magnetic flux. The scheme requires only standard optical access, and is robust to weak particle interactions.

  9. NdFeB Magnets Aligned in a 9-T Superconducting Solenoid (asterisk)

    Mulcahy, T. M.; Hull, J. R.

    2002-08-01

    Commercial-grade magnet powder (Magnequench UG) was uniaxial die-pressed into cylindrical compacts, while being aligned in the 1-T to 8-T DC field of a superconducting solenoid at Argonne National Laboratory. Then, the compacts were added to normal Magnequench UG production batches for sintering and annealing. The variations in magnet properties for different strengths of alignment fields are reported for 15.88-mm (5/8-in.) diameter compacts made with length-to-diameter (L/D) ratios in the range 3 0.25 and L 1. The best magnets were produced when the powder-filled die was inserted into the active field of the solenoid and then pressed. Improvements in the residual flux density of 8% and in the energy product of 16% were achieved by increasing the alignment field beyond the typical 2-T capabilities of electromagnets. The most improvement was achieved for the compacts with the smallest L/D ratio. The ability to make very strong magnets with small L/D, where self-demagnetization effects during alignment are greatest, would benefit most the production of near-final-shape magnets. Compaction of the magnet powder using a horizontal die and a continuously active superconducting solenoid was not a problem. Although the press was operated in the batch mode for this proof-of-concept study, its design is intended to enable automated production.

  10. Coherent and semiclassical states in magnetic field in the presence of the Aharonov-Bohm solenoid

    Bagrov, V G; Gitman, D M; Filho, D P Meira

    2010-01-01

    A new approach to constructing coherent states (CS) and semiclassical states (SS) in magnetic-solenoid field is proposed. The main idea is based on the fact that the AB solenoid breaks the translational symmetry in the xy-plane, this has a topological effect such that there appear two types of trajectories which embrace and do not embrace the solenoid. Due to this fact, one has to construct two different kinds of CS/SS, which correspond to such trajectories in the semiclassical limit. Following this idea, we construct CS in two steps, first the instantaneous CS (ICS) and the time dependent CS/SS as an evolution of the ICS. The construction is realized for nonrelativistic and relativistic, spinning and spinless particles both in (2+1)- and (3+1)- dimensions and gives a non-trivial example of SS/CS for systems with a nonquadratic Hamiltonian. It is stressed that CS depending on their parameters (quantum numbers) describe both pure quantum and semiclassical states. An analysis is represented that classifies para...

  11. Effect of superconducting solenoid model cores on spanwise iron magnet roll control

    Britcher, C. P.

    1985-01-01

    Compared with conventional ferromagnetic fuselage cores, superconducting solenoid cores appear to offer significant reductions in the projected cost of a large wind tunnel magnetic suspension and balance system. The provision of sufficient magnetic roll torque capability has been a long-standing problem with all magnetic suspension and balance systems; and the spanwise iron magnet scheme appears to be the most powerful system available. This scheme utilizes iron cores which are installed in the wings of the model. It was anticipated that the magnetization of these cores, and hence the roll torque generated, would be affected by the powerful external magnetic field of the superconducting solenoid. A preliminary study has been made of the effect of the superconducting solenoid fuselage model core concept on the spanwise iron magnet roll torque generation schemes. Computed data for one representative configuration indicate that reductions in available roll torque occur over a range of applied magnetic field levels. These results indicate that a 30-percent increase in roll electromagnet capacity over that previously determined will be required for a representative 8-foot wind tunnel magnetic suspension and balance system design.

  12. Radiation and thermal analysis of production solenoid for Mu2e experimental setup

    Pronskikh, V S; Mokhov, N V

    2011-01-01

    The Muon-to-Electron (Mu2e) experiment at Fermilab, will seek the evidence of direct muon to electron conversion at the sensitivity level where it cannot be explained by the Standard Model. An 8-GeV 25-kW proton beam will be directed onto a tilted gold target inside a large-bore superconducting Production Solenoid (PS) with the peak field on the axis of ~5T. The negative muons resulting from the pion decay will be captured in the PS aperture and directed by an S-shaped Transport Solenoid towards the stopping target inside the Detector Solenoid. In order for the superconducting magnets to operate reliably and with a sufficient safety margin, the peak neutron flux entering the coils must be reduced by 3 orders of magnitude that is achieved by means of a sophisticated absorber placed in the magnet aperture. The proposed absorber, consisting of W- and Cu-based alloy parts, is optimized for the performance and cost. Results of MARS15 simulations of energy deposition and radiation are reported. The results of the P...

  13. A multiscale and multiphysics model of strain development in a 1.5 T MRI magnet designed with 36 filament composite MgB2 superconducting wire

    Amin, Abdullah Al; Baig, Tanvir; Deissler, Robert J.; Yao, Zhen; Tomsic, Michael; Doll, David; Akkus, Ozan; Martens, Michael

    2016-05-01

    High temperature superconductors such as MgB2 focus on conduction cooling of electromagnets that eliminates the use of liquid helium. With the recent advances in the strain sustainability of MgB2, a full body 1.5 T conduction cooled magnetic resonance imaging (MRI) magnet shows promise. In this article, a 36 filament MgB2 superconducting wire is considered for a 1.5 T full-body MRI system and is analyzed in terms of strain development. In order to facilitate analysis, this composite wire is homogenized and the orthotropic wire material properties are employed to solve for strain development using a 2D-axisymmetric finite element analysis (FEA) model of the entire set of MRI magnet. The entire multiscale multiphysics analysis is considered from the wire to the magnet bundles addressing winding, cooling and electromagnetic excitation. The FEA solution is verified with proven analytical equations and acceptable agreement is reported. The results show a maximum mechanical strain development of 0.06% that is within the failure criteria of -0.6% to 0.4% (-0.3% to 0.2% for design) for the 36 filament MgB2 wire. Therefore, the study indicates the safe operation of the conduction cooled MgB2 based MRI magnet as far as strain development is concerned.

  14. Evaluation of the susceptibility artifacts and tissue injury caused by implanted microchips in dogs on 1.5 T magnetic resonance imaging.

    Saito, Miyoko; Ono, Shin; Kayanuma, Hideki; Honnami, Muneki; Muto, Makoto; Une, Yumi

    2010-05-01

    Performing magnetic resonance imaging (MRI) in patients with a metallic implant raises concern over the potential complications, including susceptibility artifacts, implant migration, and heat injury. The purpose of this study was to investigate these complications in dogs with implanted microchips by evaluating MR images and the histopathological changes after 1.5 Tesla (T) MRI. Five dogs underwent microchip implantation in the cervicothoracic area. One month later, the area was imaged using 1.5T MRI in three dogs. The microchips were removed surgically together with the surrounding tissue in all dogs. There was significant signal loss and image distortion over a wide range around the area where the microchip was implanted. This change was consistent with susceptibility artifacts, which rendered the affected area including the spinal cord undiagnostic. The artifact was more extensive in T2*-weighted images (gradient-echo) and less extensive in proton density-weighted images (fast spin-echo with short echo time). Histopathologically, all microchips were well-encapsulated with granulation tissue, and there were no evidence of migration of microchips. Cell debris and a moderate number of degenerated cells with fibrin were seen in the inner layer of the granulation tissue in each dog that underwent MRI. These changes were very subtle and did not seem to be clinically significant. The results of this study suggest that, in 1.5T MRI, susceptibility artifacts produced by implanted microchips can be marked, although the dogs with implants appeared to be scanned safely.

  15. The Silicon Sensors for the Compact Muon Solenoid Tracker - Design and Qualification Procedure

    Agram, Jean-Laurent; Assouak, Samia; Bergauer T.; Bilei, Gian Mario; Borrello, Laura; Brianzi, Mirko; Civinini, Carlo; Dierlamm, Alexander; Dinu, Nicoleta; Demaria, Natale; Feld, Lutz; Focardi, Ettore; Fontaine, Jean-Charles; Forton, Eric; Furgeri, Alexander; Hartmann, Frank; Honma, Alan; Juillot, Pierre; Kartashov, Dmitry; Krammer, Manfred; Macchiolo, Anna; Mannelli, Marcello; Messineo, Alberto; Migliore, Ernesto; Militaru, Otilia; Piasecki, Christian; Santinelli, Roberto; Sentenac, Daniel; Servoli, Leonello; Starodumov, Andrei; Tonelli, Guido; Wang, Jason

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. Its inner tracking system consist of the world largest Silicon Strip Tracker (SST). In total it implements 24244 silicon sensors covering an area of 206 m^2. To construct a large system of this size and ensure its functionality for the full lifetime of ten years under LHC condition, the CMS collaboration developed an elaborate design and a detailed quality assurance program. This paper describes the strategy and shows first results on sensor qualification.

  16. Slice emittance measurement for photocathode RF gun with solenoid scanning and RF deflecting cavity

    Li, Chen; Huang, WenHui; Du, YingChao; Yan, LiXin; Tang, ChuanXiang

    2011-12-01

    The radiation of high-gain short-wavelength free-electron laser depends on the slice transverse emittance of the electron bunch. This essay introduces the method of slice emittance measurement, and shows the brief setup of this experiment using the solenoid scanning and RF deflecting cavity at Tsinghua University. The preliminary experimental results show that the slice rms emittance of the electron bunch generated by photocathode RF gun has considerable variations along the bunch and is typically less than 0.55 mm mrad for the laser rms radius of 0.4 mm.

  17. Slice emittance measurement for photocathode RF gun with solenoid scanning and RF deflecting cavity

    2011-01-01

    The radiation of high-gain short-wavelength free-electron laser depends on the slice transverse emittance of the electron bunch. This essay introduces the method of slice emittance measurement, and shows the brief setup of this experiment using the solenoid scanning and RF deflecting cavity at Tsinghua University. The preliminary experimental results show that the slice rms emittance of the electron bunch generated by photocathode RF gun has considerable variations along the bunch and is typically less than 0.55 mm mrad for the laser rms radius of 0.4 mm.

  18. INVESTIGATION ON THE DYNAMIC RESPONSE PERFORMANCE OF A NOVEL THREE-WAY SOLENOID VALVE

    2006-01-01

    In order to meet the increasinglystrict emissionstandards andi mprove the perfor mance of diesel en-gines,using electronic control systemin diesel en-gines becomes more and more popular.In the com-mon-rail injection system of diesel engines,injec-tion ti ming and injection duration are controlled bythe solenoid valve.The perfor mance of common-rail injection systemis directly deter mined by thesolenoid valve[1-2].A novel high-speed three-waysolenoid valve used in the common-rail injectionsystem for DME powe...

  19. Self-consistent Kinetic Description of the Low-Pressure Solenoidal Inductively Coupled Argon Discharge

    毛明; 王友年

    2005-01-01

    Using an one-dimensional slab model, we have studied the electron energy distribution, the anomalous skin effect, and power absorption in the solenoidal-inductively-coupled argon discharge under low pressures (≤1.33 Pa). The electron energy distribution function and rf electromagnetic field in the plasma are determined self-consistently by the linearized Bolztmann equation incorporating with the Maxwell equations. The numerical results show that, at low pressures, the electron energy distribution function exhibits a non-Maxwellian distribution with a long high-energy tail. The anomalous skin effect is greatly enhanced under low pressures and the negative power absorption is also obtained.

  20. Transport of intense proton beams in an induction linac by solenoid lenses

    Namkung, W.; Choe, J. Y.; Uhm, H. S.

    1986-01-01

    In the proposed proton induction linac at NSWC, a 100 A and 3 μs proton beam is accelerated to 5 MeV through a series of accelerating gaps. This beam can be effectively focused by solenoid lenses in this low energy regime and can be transported by adjusting the focusing strength in each period. For the transport channel design to reduce the number of independently controlled lenses, a theory of matched beams in the space-charge dominated regime has been developed. This study can be applied to cost efficient designs of induction accelerators for heavy ion fusion and free electron lasers.

  1. Spherical aberration from trajectories in real and hard-edge solenoid fields

    BISWAS B

    2016-06-01

    For analytical, real and hard-edge solenoidal axial magnetic fields, the low-energy electron trajectories are obtained using the third-order paraxial ray equation. Using the particle trajectories, it is shown that the spherical aberration in the hard-edge model is high and it increases monotonously with hard edginess, although the focal length converges, in agreement with a recentfield and spherical aberration model. The model paved the way for a hard-edge approximation that gives correct focal length and spherical aberration, which is verified here by the trajectory method. In essence, we show that exact hard-edge fields give infinite spherical aberrations.

  2. 气压式电子驻车制动电磁阀控制特性%Characteristics of solenoid valve in electronic parking brake system control

    黄涤; 王洪亮; 皮大伟; 石秉良; 李楠

    2016-01-01

    In order to realize the automatic control of a pneumatic parking brake system,the charging and discharging characteristics of the parking control valves and its control method is studied. Analysing the structure and working principle of a heavy duty car parking brake system,this paper designs an overall scheme of the pneumatic electronic parking brake system. The mechanical properties of the spring brake cylinder is analyzed. The charging and discharging characteristics of the electromagnetic valve is studied and compared with the traditional manual valve. The control method of the pulse width modulation( PWM) is analyzed. The relationship between the inflation rate and the PWM duty ratio of the control valve is studied. The experimental results show that the solenoid valve can preserve pressure according to the demand and can adjust the aeration rate of the solenoid valve by changing the PWM signal duty ratio.%为实现气压式驻车制动系统的自动控制,研究了驻车控制阀的充放气特性及控制方法.通过分析重型车驻车制动系统的结构及工作原理,设计了气压式电子驻车制动系统的总体方案. 分析了弹簧制动缸的力学性能,对电磁阀的快速充放气特性进行了研究,并与传统手动阀做了比较. 分析了脉冲宽度调制( Pulse width modulation,PWM)的控制方法,研究了驻车制动系统控制阀在PWM控制下占空比与充气速率的关系. 实验结果证明电磁阀可按需求保压并且可通过改变PWM信号占空比调节电磁阀充气速率.

  3. SolCalc: A Suite for the Calculation and the Display of Magnetic Fields Generated by Solenoid Systems

    Lopes, M. L. [Fermilab

    2014-07-01

    SolCalc is a software suite that computes and displays magnetic fields generated by a three dimensional (3D) solenoid system. Examples of such systems are the Mu2e magnet system and Helical Solenoids for muon cooling systems. SolCalc was originally coded in Matlab, and later upgraded to a compiled version (called MEX) to improve solving speed. Matlab was chosen because its graphical capabilities represent an attractive feature over other computer languages. Solenoid geometries can be created using any text editor or spread sheets and can be displayed dynamically in 3D. Fields are computed from any given list of coordinates. The field distribution on the surfaces of the coils can be displayed as well. SolCalc was benchmarked against a well-known commercial software for speed and accuracy and the results compared favorably.

  4. Beam collimation and energy spectrum compression of laser-accelerated proton beams using solenoid field and RF cavity

    Teng, J.; Gu, Y. Q.; Zhu, B.; Hong, W.; Zhao, Z. Q.; Zhou, W. M.; Cao, L. F.

    2013-11-01

    This paper presents a new method of laser produced proton beam collimation and spectrum compression using a combination of a solenoid field and a RF cavity. The solenoid collects laser-driven protons efficiently within an angle that is smaller than 12 degrees because it is mounted few millimeters from the target, and collimates protons with energies around 2.3 MeV. The collimated proton beam then passes through a RF cavity to allow compression of the spectrum. Particle-in-cell (PIC) simulations demonstrate the proton beam transport in the solenoid and RF electric fields. Excellent energy compression and collection efficiency of protons are presented. This method for proton beam optimization is suitable for high repetition-rate laser acceleration proton beams, which could be used as an injector for a conventional proton accelerator.

  5. Macrophages homing to metastatic lymph nodes can be monitored with ultrasensitive ferromagnetic iron-oxide nanocubes and a 1.5T clinical MR scanner.

    Hye Rim Cho

    Full Text Available BACKGROUND: Due to the ability of macrophages to specifically home to tumors, their potential use as a delivery vehicle for cancer therapeutics has been suggested. Tracking the delivery and engraftment of macrophages into human tumors with a 1.5T clinical MR scanner requires the development of sensitive contrast agents for cell labeling. Therefore, this study aimed to determine whether intravenously injected macrophages could target a primary tumor as well as metastatic LNs, and whether these cells could be detected in vivo by MRI. METHODOLOGY: Peritoneal macrophages were obtained from BALB/c nude mice. The viability, phagocytotic capacity and migratory activity of the macrophages were assessed. MR imaging was performed using a clinical 1.5 T MR scanner and we estimated the T2* of the labeled macrophages. Metastatic lymph nodes were produced in BALB/c nude mice. We administrated 2×10⁶ macrophages labeled with 50 µg Fe/mL FIONs intravenously into the mice. In the 3D T2* GRE MR images obtained one day after the injection of the labeled macrophages or FION solution, the percentages of pixels in the tumors or LNs below the minimum normalized SI (signal intensity threshold were summated and reported as the black pixel count (% for the FION hypointensity. Tumors in the main tumor model as well as the brachial, axillary and inguinal lymph nodes in the metastatic LN models were removed and stained. For all statistical analyses, single-group data were assessed using t test or the Mann-Whitney test. Repeated measurements analysis of variance (ANOVA with Tukey-Kramer post hoc comparisons were performed for multiple comparisons. CONCLUSIONS: The FION-labeled macrophages, which could be non-invasively monitored using a 1.5T clinical MR scanner, targeted both the main tumors and LN metastases. Overall, the results of this study suggest that the use of macrophages may have many future applications in the clinic for vectorizing therapeutic agents toward main tumors as well as LN metastases.

  6. Chromatic, geometric and space charge effects on laser accelerated protons focused by a solenoid

    Al-Omari, Husam; Hofmann, Ingo; Ratzinger, Ulrich

    2011-01-01

    We stud­ied nu­mer­i­cal­ly emit­tance and trans­mis­sion ef­fects by chro­mat­ic and ge­o­met­ric aber­ra­tions, with and with­out space charge, for a pro­ton beam be­hind a solenoid in the laser pro­ton ex­per­i­ment LIGHT at GSI. The TraceWin code was em­ployed using a field map for the solenoid and an ini­tial dis­tri­bu­tion with ex­po­nen­tial en­er­gy de­pen­dence close to the ex­per­i­ment. The re­sults show a strong ef­fect of chro­mat­ic, and a rel­a­tive­ly weak one of ge­o­met­ric...

  7. Highly sensitive giant magnetoimpedance in a solenoid containing FeCo-based ribbon

    Fang Yun-Zhang; Xu Qi-Ming; Zheng Jin-Ju; Wu Feng-Min; Ye Hui-Qun; Si Jian-Xiao; Zheng Jian-Long; Fan Xiao-Zhen; Yang Xiao-Hong

    2012-01-01

    The highly sensitive giant magneto-impedance effect in a solenoid containing a magnetic core of Fe36Co36Nb4Si4.sB19.2 (FeCo-based) ribbon under a weak magnetic field (WMF) is presented in this paper. The FeCo-based amorphous ribbon is prepared by single roller quenching and annealed with Joule heat in a flowing nitrogen atmosphere.The giant magnetoimpedance effect in solenoid (GMIES) profiles are measured with an HP4294A impedance analyzer.The result shows that the GMIES responds to the WMF sensitively (as high as 1580 %/A·m-l).The high sensitivity can be obtained in a moderate narrow range of annealing current density (30-34 A/mm2) and closely depends on the driven current frequency.The highest sensitivity (1580 %/A.m-1) is obtained when the FeCobased amorphous ribbon is annealed at 32 A/mm2 for 10 min and then driven with an alterning current (AC) at the frequency of 350 kHz.The highly sensitive GMIES under the WMF may result from the multiple magnetic-anisotropic structure,which is induced by the temperature gradient produced during Joule-heating the ribbon.

  8. Forced Two-Phase Helium Cooling Scheme for the Mu2e Transport Solenoid

    Tatkowski, G. [Fermilab; Cheban, S. [Fermilab; Dhanaraj, N. [Fermilab; Evbota, D. [Fermilab; Lopes, M. [Fermilab; Nicol, T. [Fermilab; Sanders, R. [Fermilab; Schmitt, R. [Fermilab; Voirin, E. [Fermilab

    2015-01-01

    The Mu2e Transport Solenoid (TS) is an S-shaped magnet formed by two separate but similar magnets, TS-u and TS-d. Each magnet is quarter-toroid shaped with a centerline radius of approximately 3 m utilizing a helium cooling loop consisting of 25 to 27 horizontal-axis rings connected in series. This cooling loop configuration has been deemed adequate for cooling via forced single phase liquid helium; however it presents major challenges to forced two-phase flow such as “garden hose” pressure drop, concerns of flow separation from tube walls, difficulty of calculation, etc. Even with these disadvantages, forced two-phase flow has certain inherent advantages which make it a more attractive option than forced single phase flow. It is for this reason that the use of forced two-phase flow was studied for the TS magnets. This paper will describe the analysis using helium-specific pressure drop correlations, conservative engineering approach, helium properties calculated and updated at over fifty points, and how the results compared with those in literature. Based on the findings, the use of forced-two phase helium is determined to be feasible for steady-state cooling of the TS solenoids

  9. Progress on Design and Construction of a MuCool Coupling Solenoid Magnet

    Wang, L.; Liu, Xiao Kun; Xu, FengYu; Li, S.; Pan, Heng; Wu, Hong; Guo, Xinglong; Zheng, ShiXian; Li, Derun; Virostek, Steve; Zisman, Mike; Green, M.A.

    2010-06-28

    The MuCool program undertaken by the US Neutrino Factory and Muon Collider Collaboration is to study the behavior of muon ionization cooling channel components. A single superconducting coupling solenoid magnet is necessary to pursue the research and development work on the performance of high gradient, large size RF cavities immersed in magnetic field, which is one of the main challenges in the practical realization of ionization cooling of muons. The MuCool coupling magnet is to be built using commercial copper based niobium titanium conductors and cooled by two cryo-coolers with each cooling capacity of 1.5 W at 4.2 K. The solenoid magnet will be powered by using a single 300A power supply through a single pair of binary leads that are designed to carry a maximum current of 210A. The magnet is to be passively protected by cold diodes and resistors across sections of the coil and by quench back from the 6061 Al mandrel in order to lower the quench voltage and the hot spot temperature. The magnet is currently under construction. This paper presents the updated design and fabrication progress on the MuCool coupling magnet.

  10. Electrical characterization of S/C conductor for the CMS solenoid

    Fabbricatore, P; Farinon, S; Greco, Michela; Kircher, F; Musenich, R

    2005-01-01

    The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. The coil is wound from 20 high purity aluminum-stabilized NbTi conductors with a total length of 45 km. The main peculiarity of the CMS magnet among other existing thin detector solenoids is its sandwich-type aluminum-stabilized superconductor. This special feature was chosen in order to have a mechanically self-supporting winding structure. We measured the critical current of all the 21 finished conductors in fields up to 6 T using the Ma.Ri.S.A. test facility at INFN-Genova. We compare these results with the critical current of single strands measured by CEA- Saclay, extracted from the conductor after the co-extrusion. A comparison among the measurements provides information about the possible critical current degradation and assures an accurate quality control of the conductor pr...

  11. Estimation and measurement of flat or solenoidal coil inductance for radiofrequency NMR coil design.

    Rainey, Jan K; DeVries, Jeffrey S; Sykes, Brian D

    2007-07-01

    The inductance of a radiofrequency coil determines its compatibility with a given NMR probe circuit. However, calculation (or estimation) of inductance for radiofrequency coils of dimensions suitable for use in an NMR probe is not trivial, particularly for flat-coils. A comparison of a number of formulae for calculation of inductance is presented through the use of a straightforward inductance measurement circuit. This technique relies upon instrumentation available in many NMR laboratories rather than upon more expensive and specialized instrumentation often utilized in the literature. Inductance estimation methods are suggested and validated for both flat-coils and solenoids. These have proven very useful for fabrication of a number of new coils in our laboratory for use in static solid-state NMR probes operating at (1)H frequencies of 300 and 600MHz. Solenoidal coils with very similar measured and estimated inductances having inner diameters from 1 to 5mm are directly compared as an example of the practical application of inductance estimation for interchange of coils within an existing solid-state NMR probe.

  12. The link between solenoidal turbulence and slow star formation in G0.253+0.016

    Federrath, C; Longmore, S N; Kruijssen, J M D; Bally, J; Contreras, Y; Crocker, R M; Garay, G; Jackson, J M; Testi, L; Walsh, A J

    2016-01-01

    Star formation in the Galactic disc is primarily controlled by gravity, turbulence, and magnetic fields. It is not clear that this also applies to star formation near the Galactic Centre. Here we determine the turbulence and star formation in the CMZ cloud G0.253+0.016. Using maps of 3mm dust emission and HNCO intensity-weighted velocity obtained with ALMA, we measure the volume-density variance $\\sigma_{\\rho/\\rho_0} = 1.3 \\pm 0.5$ and turbulent Mach number $\\mathcal{M} = 11 \\pm 3$. Combining these with turbulence simulations to constrain the plasma $\\beta = 0.34 \\pm 0.35$, we reconstruct the turbulence driving parameter $b = 0.22 \\pm 0.12$ in G0.253+0.016. This low value of $b$ indicates solenoidal (divergence-free) driving of the turbulence in G0.253+0.016. By contrast, typical clouds in the Milky Way disc and spiral arms have a significant compressive (curl-free) driving component ($b > 0.4$). We speculate that shear causes the solenoidal driving in G0.253+0.016 and show that this may reduce the star forma...

  13. Low-energy nuclear reactions with double-solenoid- based radioactive nuclear beam

    Valdir Guimarães

    2010-07-01

    The University of Notre Dame, USA (Becchetti et al, Nucl. Instrum. Methods Res. A505, 377 (2003)) and later the University of São Paulo, Brazil (Lichtenthaler et al, Eur. Phys. J. A25, S-01, 733 (2005)) adopted a system based on superconducting solenoids to produce low-energy radioactive nuclear beams. In these systems the solenoids act as thick lenses to collect, select, and focus the secondary beam into a scattering chamber. Many experiments with radioactive light particle beams (RNB) such as 6He, 7Be, 8Li, 8B have been performed at these two facilities. These low-energy RNB have been used to investigate low-energy reactions such as elastic scattering, transfer and breakup, providing useful information on the structure of light nuclei near the drip line and on astrophysics. Total reaction cross-sections, derived from elastic scattering analysis, have also been investigated for light system as a function of energy and the role of breakup of weakly bound or exotic nuclei is discussed.

  14. Pulse Voltammetry.

    Osteryoung, Janet

    1983-01-01

    Discusses the nature of pulse voltammetry, indicating that its widespread use arises from good sensitivity and detection limits and from ease of application and low cost. Provides analytical and mechanistic applications of the procedure. (JN)

  15. Comparison of optimized 3D-SPACE and 3D-TSE sequences at 1.5T MRCP in the diagnosis of choledocholithiasis

    Sudholt, P. [University Hospital Marburg (Germany). Dept. of Diagnostic and Interventional Radiology; Zaehringer, C.; Tyndall, A.; Bongartz, G.; Hohmann, J. [University Hospital Basel (Switzerland). Clinic for Radiology and Nuclear Medicine; Urigo, C. [Ars Medica Clinic, Gravesano-Lugano (Switzerland). Radiology

    2015-06-15

    The aim of the study was to evaluate whether or not MRCP using a 3D-SPACE sequence allows for better image quality and a higher level of diagnostic confidence than a conventional 3D-TSE sequence at 1.5T regarding the diagnosis of choledocholithiasis in a routine clinical setting. 3D-SPACE and 3D-TSE sequences were performed in 42 consecutive patients with suspected choledocholithiasis undergoing MRCP. Evaluation of image quality and diagnostic confidence was done on the pancreaticobiliary tree which was subdivided into 10 segments. They were scored and statistically evaluated separately for visibility and diagnostic certainty by three radiologists with differing levels of experience on a five-point scale of 1 to 5 and -2 to 2, respectively. Student t-test was performed, and the interobserver agreement was also calculated. Image quality for each segment was significantly better for the 3D-SPACE sequence compared to the 3D-TSE sequence (4.48±0.94 vs. 3.98±1.20; 5-point scale p<0.01). Diagnostic confidence for the reporting radiologist was also significantly better for 3D-SPACE than for 3D-TSE (1.68±0.56 vs. 1.46±0.70; 3-point scale; p<0.01). The interobserver agreement was high in both sequences, 0.62-0.83 and 0.64-0.82, respectively. The optimized 3D-SPACE sequence allows for better image quality in 1.5T MRCP examinations and leads to a higher diagnostic confidence for choledocholithiasis compared to the conventional 3D-TSE sequence.

  16. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid; Resonance magnetique nucleaire a 310 MHz dans un solenoide supra-conducteur

    Dunand, J.J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [French] Dans la premiere partie est exposee la realisation d'un spectrometre de RMN utilisant un solenoide supraconducteur. Des solutions sont donnees pour obtenir la meilleure homogeneite possible du champ magnetique et pour minimiser les sources d'erreur apportees par le spectrometre. La deuxieme partie est consacree a l'etude d'elastomeres et de radicaux libres nitroxydes. Une variation de la temperature de transition avec le champ magnetique est mise en evidence pour les elastomeres. L'accroissement du deplacement paramagnetique a permis une etude complete par RMN des radicaux libres nitroxydes piperidiniques et pyrrolidiniques. (auteur)

  17. Signal-shot echo-planner diffusion-weighted MR imaging at 3T and 1.5T for differentiation of benign vertebral fracture edema and tumor infiltration

    Park, Hee Jin; Lee, So Yeon; Rho, Myung Ho; Chung, Eun Chul; Kim, Mi Sung; Kwon, Heon Ju; Youn, In Young [Dept. of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2016-09-15

    To compare the apparent diffusion coefficient (ADC) value using single-shot echo-planar imaging sequences at 3T and 1.5T for differentiation of benign fracture edema and tumor infiltration of the vertebral body. A total of 46 spinal examinations were included in the 1.5T MRI group, and a total of 40 spinal examinations were included in the 3T MRI group. The ADC values of the lesion were measured and calculated. The diagnostic performance of the conventional MR image containing sagittal T2-weighted fat saturated image and each diffusion weighted image (DWI) with an ADC value with different b values were evaluated. The mean ADC value of the benign lesions was higher than that of the malignant lesions on 1.5T and 3T (p < 0.05). The sensitivity of the diagnostic performance was higher with an additional DWI in both 1.5T and 3T, but the sensitivities were similar with the addition of b values of 400 and 1000. The specificities of the diagnostic performances did not show significant differences (p value > 0.05). The diagnostic accuracies were higher when either of the DWIs (b values of 400 and 1000) was added to routine MR image for 1.5T and 3T. Statistical differences between 1.5T and 3T or between b values of 400 and 1000 were not seen. The ADC values of the benign lesions were significantly higher than those of the malignant lesions on 1.5T and 3T. There was no statistically significant difference in the diagnostic performances when either of the DWIs (b values of 400 and 1000) was added to the routine MR image for 1.5T and 3T.

  18. Single-Shot Echo-Planar Diffusion-Weighted MR Imaging at 3T and 1.5T for Differentiation of Benign Vertebral Fracture Edema and Tumor Infiltration

    Park, Hee Jin; Lee, So Yeon; Rho, Myung Ho; Chung, Eun Chul; Kim, Mi Sung; Kwon, Heon Ju; Youn, In Young [Department of Radiology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul 03181 (Korea, Republic of)

    2016-11-01

    To compare the apparent diffusion coefficient (ADC) value using single-shot echo-planar imaging sequences at 3T and 1.5T for differentiation of benign fracture edema and tumor infiltration of the vertebral body. A total of 46 spinal examinations were included in the 1.5T MRI group, and a total of 40 spinal examinations were included in the 3T MRI group. The ADC values of the lesion were measured and calculated. The diagnostic performance of the conventional MR image containing sagittal T2-weighted fat saturated image and each diffusion weighted image (DWI) with an ADC value with different b values were evaluated. The mean ADC value of the benign lesions was higher than that of the malignant lesions on 1.5T and 3T (p < 0.05). The sensitivity of the diagnostic performance was higher with an additional DWI in both 1.5T and 3T, but the sensitivities were similar with the addition of b values of 400 and 1000. The specificities of the diagnostic performances did not show significant differences (p value > 0.05). The diagnostic accuracies were higher when either of the DWIs (b values of 400 and 1000) was added to routine MR image for 1.5T and 3T. Statistical differences between 1.5T and 3T or between b values of 400 and 1000 were not seen. The ADC values of the benign lesions were significantly higher than those of the malignant lesions on 1.5T and 3T. There was no statistically significant difference in the diagnostic performances when either of the DWIs (b values of 400 and 1000) was added to the routine MR image for 1.5T and 3T.

  19. Optimization for response time of solenoid valve through response surface methodology%基于响应面法的电磁阀响应时间优化

    蒋焕煜; 张利君; 周鸣川; 施玮囡

    2016-01-01

    为了缩短喷雾植保用电磁阀的响应时间,提高变量喷雾的精准性,该文引入响应面法优化改进型脉冲宽度调制(pulse width modulation,PWM)控制参数。试验采用Box-Behnken设计方法,选取电磁阀驱动电压(10、12和14 V)、PWM延迟时间(15、40和65 ms)及PWM占空比(5%,15%和25%)作为考察因素,以电磁阀开启响应时间、电磁阀闭合响应时间和电磁阀响应时间为响应值,获取了关于3个响应值的二次多项回归模型,并对其进行了验证。经响应面法分析得出,在参数优化区间内,使电磁阀响应时间最短的参数条件为电磁阀驱动电压12 V、PWM延迟时间15 ms以及PWM占空比5%,与试验测量结果差异极小。与普通PWM控制方式相比,使用改进型PWM控制信号并优化控制参数可有效缩短电磁阀响应时间。该研究为合理选择PWM控制参数提供了参考。%Solenoid valve driven by PWM (pulse width modulation) control signal is used as interface between electronic control and fluid flow in precision spraying, the response time of which has huge impact on the performance of precise spray system. Longer response time would reduce the accuracy of spraying and increase the overuse of chemical. A modified PWM technology (with much higher frequency for controlling the holding current) was applied and 3 parameters of PWM control signal containing driving voltage, delayed time and duty cycle were optimized by RSM (response surface methodology) to shorten the response time, which was composed of opening response time and closing response time. The optimization of parameters was carried out through the BBD (Box-Behnken design) with 3 factors and 3 levels. The critical factors (and their values) selected for the research were driving voltage (10, 12 and 14 V), delayed time (15, 40 and 65 ms) and duty cycle (5%, 15% and 25%). In order to better explore the influence of factors on each response

  20. Use of a probing pulsed magnetic field for determining plasma parameters

    Rousskikh, A. G.; Oreshkin, V. I.; Zhigalin, A. S.; Yushkov, G. Yu.

    2016-11-01

    A novel, simple, and readily usable method is proposed for measuring the electrical conductivity and temperature of a plasma. The method is based on the interaction of the test plasma with a pulsed magnetic field. The electric signals induced by the magnetic field in the circuits of two probes (miniature solenoids), one immersed in the test plasma and the other placed outside the plasma, provide data for estimating the plasma parameters. The method was verified experimentally by determining the parameters of the plasma flows generated in the cathode spots high-current pulsed vacuum arcs that were used to form cylindrical shells of bismuth Z-pinch plasma.

  1. Design and fabrication of a 30 T superconducting solenoid using overpressure processed Bi2212 round wire

    Flanagan, Gene [Muons, Inc., Batavia, IL (United States); Johnson, Rolland [Muons, Inc., Batavia, IL (United States)

    2016-02-18

    High field superconducting magnets are used in particle colliders, fusion energy devices, and spectrometers for medical imaging and advanced materials research. Magnets capable of generating fields of 20-30 T are needed by future accelerator facilities. A 20-30 T magnet will require the use of high-temperature superconductors (HTS) and therefore the challenges of high field HTS magnet development need to be addressed. Superconducting Bi2Sr2CaCu2Ox (Bi2212) conductors fabricated by the oxide-powder-in-tube (OPIT) technique have demonstrated the capability to carry large critical current density of 105 A/cm2 at 4.2 K and in magnetic fields up to 45 T. Available in round wire multi-filamentary form, Bi2212 may allow fabrication of 20-50 T superconducting magnets. Until recently the performance of Bi2212 has been limited by challenges in realizing high current densities (Jc ) in long lengths. This problem now is solved by the National High Magnetic Field Lab using an overpressure (OP) processing technique, which uses external pressure to process the conductor. OP processing also helps remove the ceramic leakage that results when Bi-2212 liquid leaks out from the sheath material and reacts with insulation, coil forms, and flanges. Significant advances have also been achieved in developing novel insulation materials (TiO2 coating) and Ag-Al sheath materials that have higher mechanical strengths than Ag-0.2wt.% Mg, developing heat treatment approaches to broadening the maximum process temperature window, and developing high-strength, mechanical reinforced Bi-2212 cables. In the Phase I work, we leveraged these new opportunities to prototype overpressure processed solenoids and test them in background fields of up to 14 T. Additionally a design of a fully superconducting 30 T solenoid was produced. This work in conjunction with the future path outlined in the Phase II proposal would

  2. Pulse plating

    Hansal, Wolfgang E G; Green, Todd; Leisner, Peter; Reichenbach, Andreas

    2012-01-01

    The electrodeposition of metals using pulsed current has achieved practical importance in recent years. Although it has long been known that changes in potential, with or without polarity reversal, can significantly affect the deposition process, the practical application of this has been slow to be adopted. This can largely be explained in terms of the complex relationship between the current regime and its effect on the electrodeposition process. In order to harness these effects, an understanding of the anodic and cathodic electrochemical processes is necessary, together with the effects of polarity reversal and the rate of such reversals. In this new monograph, the basics of metal electrodeposition from solution are laid out in great detail in seven distinct chapters. With this knowledge, the reader is able to predict how a given pulse train profile can be adopted to achieve a desired outcome. Equally important is the choice of a suitable rectifier and the ancillary control circuits to enable pulse platin...

  3. Selection of Solenoid Salve in Engineering Design%工程设计中电磁阀的选型

    彭丽; 李涛

    2012-01-01

    With safety instrument system being widely applied in petrochemical plant, solenoid valve's importance is self - evident as the execator of safety interlocking system. From the point of engineering design view, the selection and design of solenoid valve in engineering design and safety instrumentation system are explored by the introduction of classification, the advantage of low power solenoid valve,power consumption and allowable transmission distance of calculation, the ways of dual solenoid valve's pneumatic hook-up and so on.%随着安全仪表系统在石油化工装置的广泛应用,电磁阀作为控制安全联锁的执行者,起着非常重要的作用;从工程设计角度出发,通过介绍电磁阀分类,低功耗电磁阀的优势,电磁阀的功耗及允许传输距离的计算,双电磁阀气路的连接方式等,探讨电磁阀在工程设计中的选型特点以及在安全仪表系统中电磁阀的设计。

  4. A quantitative investigation of the effect of a close-fitting superconducting shield on the coil factor of a solenoid

    Aarøe, Morten; Monaco, R.; Koshelet, V.;

    2009-01-01

    Superconducting shields are commonly used to suppress external magnetic interference. We show, that an error of almost an order of magnitude can occur in the coil factor in realistic configurations of the solenoid and the shield. The reason is that the coil factor is determined by not only...

  5. Improving Code Quality of the Compact Muon Solenoid Electromagnetic Calorimeter Control Software to Increase System Maintainability

    Holme, Oliver; Dissertori, Günther; Djambazov, Lubomir; Lustermann, Werner; Zelepoukine, Serguei

    2013-01-01

    The Detector Control System (DCS) software of the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at CERN is designed primarily to enable safe and efficient operation of the detector during Large Hadron Collider (LHC) data-taking periods. Through a manual analysis of the code and the adoption of ConQAT [1], a software quality assessment toolkit, the CMS ECAL DCS team has made significant progress in reducing complexity and improving code quality, with observable results in terms of a reduction in the effort dedicated to software maintenance. This paper explains the methodology followed, including the motivation to adopt ConQAT, the specific details of how this toolkit was used and the outcomes that have been achieved. [1] ConQAT, Continuous Quality Assessment Toolkit; https://www.conqat.org/

  6. Derivation of armature displacement and movement disturbances from current and voltage measurements on solenoid operated valves

    Louati, Iskander Alexandre [AREVA NP GmbH (Germany). Service Sector Germany

    2009-07-01

    As part of the electric drive mechanisms of the safety system in nuclear power plants safety related solenoid operated valves (SOVs) are subject to design control, commissioning tests and periodical in-service inspections. AREVA has developed and qualified many methods and tools that have been embedded into as software tools called DAM for diagnosis and evaluation of the valve performance according to the KTA requirements. In the special case of COVs tracing the electric measurements with ADAM helps to detect anomalies at the SOVs and esp. those related to disturbances of the armature moved. The disturbances to be tested are divided into electrical and mechanical disturbances: voltage insufficiency, switch chattering; degradation of spring load, friction collaterally to armature displacement, partial or total obstruction of the armature.

  7. Fabrication of 3D solenoid microcoils in silica glass by femtosecond laser wet etch and microsolidics

    Meng, Xiangwei; Yang, Qing; Chen, Feng; Shan, Chao; Liu, Keyin; Li, Yanyang; Bian, Hao; Du, Guangqing; Hou, Xun

    2015-02-01

    This paper reports a flexible fabrication method for 3D solenoid microcoils in silica glass. The method consists of femtosecond laser wet etching (FLWE) and microsolidics process. The 3D microchannel with high aspect ratio is fabricated by an improved FLWE method. In the microsolidics process, an alloy was chosen as the conductive metal. The microwires are achieved by injecting liquid alloy into the microchannel, and allowing the alloy to cool and solidify. The alloy microwires with high melting point can overcome the limitation of working temperature and improve the electrical property. The geometry, the height and diameter of microcoils were flexibly fabricated by the pre-designed laser writing path, the laser power and etching time. The 3D microcoils can provide uniform magnetic field and be widely integrated in many magnetic microsystems.

  8. Refurbishment and Testing of the 1970's Era LASS Solenoid Coils for JLab's Hall D

    Anumagalla, Ravi; Biallas, George; Brindza, Paul; Carstens, Thomas; Creel, Jonathan; Egiyan, Hovanes; Martin, Floyd; Qiang, Yi; Spiegel, Scot; Stevens, Mark; Wissmann, Mark

    2012-07-01

    JLab refurbished the LASS1, 1.85 m bore Solenoid, consisting of four superconducting coils to act as the principal analysis magnet for nuclear physics in the newly constructed, Hall D at Jefferson Lab. The coils, built in 1971 at Stanford Linier Accelerator Center and used a second time at the MEGA Experiment at Los Alamos, had electrical shorts and leaks to the insulating vacuum along with deteriorated superinsulation & instrumentation. Root cause diagnosis of the problems and the repair methods are described along with the measures used to qualify the vessels and piping within the Laboratory's Pressure Safety Program (mandated by 10CFR851). The extraordinary refrigerator operational methods used to utilize the obsolete cryogenic apparatus gathered for the off-line, single coil tests are described.

  9. Failure Scenarios and Mitigations and for the BaBar Superconducting Solenoid

    Thompson, EunJoo; Candia, A.; Craddock, W.W.; Racine, M.; Weisend, J.G., II; /SLAC

    2005-12-13

    The cryogenic department at the Stanford Linear Accelerator Center is responsible for the operation, troubleshooting, and upgrade of the 1.5 Tesla superconducting solenoid detector for the BABAR B-factory experiment. Events that disable the detector are rare but significantly impact the availability of the detector for physics research. As a result, a number of systems and procedures have been developed over time to minimize the downtime of the detector, for example improved control systems, improved and automatic backup systems, and spares for all major components. Together they can prevent or mitigate many of the failures experienced by the utilities, mechanical systems, controls and instrumentation. In this paper we describe various failure scenarios, their effect on the detector, and the modifications made to mitigate the effects of the failure. As a result of these modifications the reliability of the detector has increased significantly with only 3 shutdowns of the detector due to cryogenics systems over the last 2 years.

  10. The upgrade and re-validation of the Compact Muon Solenoid Electromagnetic Calorimeter Control System

    Holme, Oliver; Di Calafiori, Diogo; Dissertori, Günther; Djambazov, Lubomir; Jovanovic, Dragoslav; Lustermann, Werner; Zelepoukine, Serguei

    2013-01-01

    The Electromagnetic Calorimeter (ECAL) is one of the sub-detectors of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN. The Detector Control System (DCS) that has been developed and implemented for the CMS ECAL was deployed in accordance with the LHC schedule and has been supporting the CMS data-taking since LHC physics runs started in 2009. During these years, the control system has been regularly adapted according to operational experience and new requirements, always respecting the constraints imposed on significant changes to a running system. Several hardware and software upgrades and system extensions were therefore deferred to the first LHC Long Shutdown (LS1). This paper presents the main architectural differences between the system that supported the CMS ECAL during its first years and the new design for the coming physics runs after LS1. Details on the upgrade planning, including the certification methods performed in the CMS ECAL DCS laboratory facilities, repor...

  11. On the effects of solenoidal and compressive turbulence in prestellar cores

    Lomax, O; Hubber, D A

    2015-01-01

    We present the results of an ensemble of SPH simulations that follow the evolution of prestellar cores for $0.2\\,{\\rm Myr}$. All the cores have the same mass, and start with the same radius, density profile, thermal and turbulent energy. Our purpose is to explore the consequences of varying the fraction of turbulent energy, $\\delta_\\mathrm{sol}$, that is solenoidal, as opposed to compressive; specifically we consider $\\delta_\\mathrm{sol}=1,\\,2/3,\\,1/3,\\,1/9\\;{\\rm and}\\;0$. For each value of $\\delta_\\mathrm{sol}$, we follow ten different realisations of the turbulent velocity field, in order also to have a measure of the stochastic variance blurring any systematic trends. With low $\\delta_\\mathrm{sol}(\\!1/3)$ disc fragmentation dominates and delivers relatively low mass stars. There are no discernible systematic trends in the multiplicity statistics obtained with different $\\delta_\\mathrm{sol}$.

  12. Analysing the Control Software of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    Hwong, Yi-Ling; Willemse, Tim A C

    2011-01-01

    The control software of the CERN Compact Muon Solenoid experiment contains over 30,000 finite state machines. These state machines are organised hierarchically: commands are sent down the hierarchy and state changes are sent upwards. The sheer size of the system makes it virtually impossible to fully understand the details of its behaviour at the macro level. This is fuelled by unclarities that already exist at the micro level. We have solved the latter problem by formally describing the finite state machines in the mCRL2 process algebra. The translation has been implemented using the ASF+SDF meta-environment, and its correctness was assessed by means of simulations and visualisations of individual finite state machines and through formal verification of subsystems of the control software. Based on the formalised semantics of the finite state machines, we have developed dedicated tooling for checking properties that can be verified on finite state machines in isolation.

  13. Extensive characterisation of advanced manufacturing solutions for the ITER Central Solenoid pre-compression system

    Langeslag, S.A.E.; Libeyre, P.; Marcinek, D.J.; Zhang, Z.

    2015-01-01

    The ITER Central Solenoid (CS), positioned in the center of the ITER tokamak, will provide a magnetic field, contributing to the confinement of the plasma. The 13 m high CS consists of a vertical stack of 6 independently driven modules, dynamically activated. Resulting opposing currents can lead to high separation forces. A pre-compression structure is implemented to counteract these opposing forces, by realising a continuous 180 MN coil-to-coil contact loading. Preload is applied by mechanical fastening via 9 subunits, positioned along the coil stack, each consisting of 2 outer and 1 inner tie plate. The tie plates therefore need to feature outstanding mechanical behaviour in a large temperature range. High strength, Nitronic®-50 type F XM-19 austenitic stainless steel is selected as candidate material. The linearised stress distribution reaches approximately 250 MPa, leading to a required yield strength of 380 MPa at room temperature. Two different manufacturing methods are being studied for the procuremen...

  14. Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids

    Caspi, S.; Dietderich, D. R.; Ferracin, P.; Finney, N. R.; Fuery, M. J.; Gourlay, S. A.; Hafalia, A. R.

    2007-06-01

    It can be shown that, by superposing two solenoid-like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is 'cos-theta' like and the resulting magnetic field in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.

  15. A feasibility study of high-strength Bi-2223 conductor for high-field solenoids

    Godeke, A.; Abraimov, D. V.; Arroyo, E.; Barret, N.; Bird, M. D.; Francis, A.; Jaroszynski, J.; Kurteva, D. V.; Markiewicz, W. D.; Marks, E. L.; Marshall, W. S.; McRae, D. M.; Noyes, P. D.; Pereira, R. C. P.; Viouchkov, Y. L.; Walsh, R. P.; White, J. M.

    2017-03-01

    We performed a feasibility study on a high-strength Bi{}2-xPb x Sr2Ca2Cu3O{}10-x(Bi-2223) tape conductor for high-field solenoid applications. The investigated conductor, DI-BSCCO Type HT-XX, is a pre-production version of Type HT-NX, which has recently become available from Sumitomo Electric Industries. It is based on their DI-BSCCO Type H tape, but laminated with a high-strength Ni-alloy. We used stress–strain characterizations, single- and double-bend tests, easy- and hard-way bent coil-turns at various radii, straight and helical samples in up to 31.2 T background field, and small 20-turn coils in up to 17 T background field to systematically determine the electro-mechanical limits in magnet-relevant conditions. In longitudinal tensile tests at 77 K, we found critical stress- and strain-levels of 516 MPa and 0.57%, respectively. In three decidedly different experiments we detected an amplification of the allowable strain with a combination of pure bending and Lorentz loading to ≥slant 0.92 % (calculated elastically at the outer tape edge). This significant strain level, and the fact that it is multi-filamentary conductor and available in the reacted and insulated state, makes DI-BSCCO HT-NX highly suitable for very high-field solenoids, for which high current densities and therefore high loads are required to retain manageable magnet dimensions.

  16. Analysis of the cooldown of the ITER central solenoid model coil and insert coil

    Bonifetto, R.; Brighenti, A.; Isono, T.; Martovetsky, N.; Kawano, K.; Savoldi, L.; Zanino, R.

    2017-01-01

    A series of superconducting insert coils (ICs) made of different materials has been tested since 2000 at JAEA Naka in the bore of the central solenoid model coil at fields up to 13 T and currents up to several tens of kA, fully representative of the ITER operating conditions. Here we focus on the 2015 test of the presently last IC of the series, the central solenoid (CS) insert coil, which was aimed at confirming the performance and properties of the Nb3Sn conductor, manufactured in Japan and used to wind the ITER CS modules in the US. As typical for these large scale applications, the cooldown (CD) from ambient to supercritical He temperature may take a long time, of the order of several weeks, so that it should be useful, also in the perspective of future IC tests, to optimize it. To that purpose, a comprehensive CD model implemented in the 4C code is developed and presented in this paper. The model is validated against the experimental data of an actual CD scenario, showing a very good agreement between simulation and measurements, from 300 to 4.5 K. The maximum temperature difference across the coil, which can only be roughly estimated from the measurements, is then extracted from the results of the simulation and shown to be much larger than the maximum value of 50 K, prescribed on the basis of the allowable thermal stress on the materials. An optimized CD scenario is finally designed using the model for the initial phase of the CD between 300 and 80 K, which allows reducing the needed time by ∼20%, while still satisfying the major constraints. Recommendations are also given for a better location/choice of the thermometers to be used for the monitoring of the maximum temperature difference across the coil.

  17. Numerical study on the quench propagation in a 1.5 T MgB2 MRI magnet design with varied wire compositions

    Poole, Charles; Baig, Tanvir; Deissler, Robert J.; Doll, David; Tomsic, Michael; Martens, Michael

    2016-04-01

    To reduce the usage of liquid helium in MRI magnets, magnesium diboride (MgB2), a high temperature superconductor, has been considered for use in a design of conduction cooled MRI magnets. Compared to NbTi wires the normal zone propagation velocity (NZPV) in MgB2 is much slower leading to a higher temperature rise and the necessity of active quench protection. The temperature rise, resistive voltage, and NZPV during a quench in a 1.5 T main magnet design with MgB2 superconducting wire was calculated for a variety of wire compositions. The quench development was modeled using the Douglas-Gunn method to solve the 3D heat equation. It was determined that wires with higher bulk thermal conductivity and lower electrical resistivity reduced the hot-spot temperature rise near the beginning of a quench. These improvements can be accomplished by increasing the copper fraction inside the wire, using a sheath material (such as Glidcop) with a higher thermal conductivity and lower electrical resistivity, and by increasing the thermal conductivity of the wire’s insulation. The focus of this paper is on the initial stages of quench development, and does not consider the later stages of the quench or magnet protection.

  18. Contrast enhancement of intracranial lesions at 1.5 T: comparison among 2D spin echo, black-blood (BB) Cube, and BB Cube-FLAIR sequences

    Im, SungWoon; Ashikaga, Ryuichiro; Yagyu, Yukinobu; Hyodo, Tomoko; Imaoka, Izumi; Kumano, Seishi; Ishii, Kazunari; Murakami, Takamichi [Kinki University Faculty of Medicine, Department of Radiology, Osaka-Sayama, Osaka (Japan); Wakayama, Tetsuya; Miyoshi, Mitsuharu [GE Healthcare Japan, MR Applications and Workflow, Asia Pacific, Hino, Tokyo (Japan)

    2015-11-15

    The purpose of this study was to investigate the usefulness of T1W black-blood Cube (BB Cube) and T1W BB Cube fluid-attenuated inversion recovery (BB Cube-FLAIR) sequences for contrast-enhanced brain imaging, by evaluating flow-related artefacts, detectability, and contrast ratio (CR) of intracranial lesions among these sequences and T1W-SE. Phantom studies were performed to determine the optimal parameters of BB Cube and BB Cube-FLAIR. A clinical study in 23 patients with intracranial lesions was performed to evaluate the usefulness of these two sequences for the diagnosis of intracranial lesions compared with the conventional 2D T1W-SE sequence. The phantom study revealed that the optimal parameters for contrast-enhanced T1W imaging were TR/TE = 500 ms/minimum in BB Cube and TR/TE/TI = 600 ms/minimum/300 ms in BB Cube-FLAIR imaging. In the clinical study, the degree of flow-related artefacts was significantly lower in BB Cube and BB Cube-FLAIR than in T1W-SE. Regarding tumour detection, BB Cube showed the best detectability; however, there were no significant differences in CR among the sequences. At 1.5 T, contrast-enhanced BB Cube was a better imaging sequence for detecting brain lesions than T1W-SE or BB Cube-FLAIR. (orig.)

  19. Numerical simulation of quench protection for a 1.5 T persistent mode MgB2 conduction-cooled MRI magnet

    Deissler, Robert J.; Baig, Tanvir; Poole, Charles; Amin, Abdullah; Doll, David; Tomsic, Michael; Martens, Michael

    2017-02-01

    The active quench protection of a 1.5 T MgB2 conduction-cooled MRI magnet operating in persistent current mode is considered. An active quench protection system relies on the detection of the resistive voltage developed in the magnet, which is used to trigger the external energizing of quench heaters located on the surfaces of all ten coil bundles. A numerical integration of the heat equation is used to determine the development of the temperature profile and the maximum temperature in the coil at the origin, or ‘hot spot’, of the quench. Both n-value of the superconductor and magnetoresistance of the wire are included in the simulations. An MgB2 wire manufactured by Hyper Tech Research, Inc. was used as the basis to model the wire for the simulations. With the proposed active quench protection system, the maximum temperature was limited to 200 K or less, which is considered low enough to prevent damage to the magnet. By substituting Glidcop for the Monel in the wire sheath or by increasing the thermal conductivity of the insulation, the margin for safe operation was further increased, the maximum temperature decreasing by more than 40 K. The strain on the MgB2 filaments is calculated using ANSYS, verifying that the stress and strain limits in the MgB2 superconductor and epoxy insulation are not exceeded.

  20. A high-field 3He Metastability Exchange Optical Pumping polarizer operating in a 1.5 T medical scanner for lung MRI

    Collier, G; Wojna, A; Głowacz, B; Suchanek, M; Olejniczak, Z; Dohnalik, T

    2013-01-01

    After being hyperpolarized using the technique of Metastability Exchange Optical Pumping (MEOP), 3He can be used as a contrast agent for lung magnetic resonance imaging (MRI). MEOP is usually performed at low magnetic field (~ 1 mT) and low pressure (~ 1 mbar), which results in a low magnetization production rate. A delicate polarization-preserving step of compression is also required. It was demonstrated in sealed cells that high nuclear polarization values can be obtained at higher pressures with MEOP, if performed at high magnetic field (non-standard conditions). In this work the feasibility of building a high-field polarizer that operates within a commercial 1.5 T scanner was evaluated. Preliminary measurements of nuclear polarization with sealed cells filled at different 3He gas pressures (1.33 to 267 mbar) were performed. The use of an annular shape for the laser beam increased by 25 % the achievable nuclear polarization equilibrium value (Meq) at 32 and 67 mbar as compared to a Gaussian beam shape. Meq...

  1. Prostate cancer: 1.5 T endo-coil dynamic contrast-enhanced MRI and MR spectroscopy-correlation with prostate biopsy and prostatectomy histopathological data

    Chabanova, Elizaveta, E-mail: elcha@heh.regionh.dk [Department of Diagnostic Radiology, Copenhagen University Hospital at Herlev (Denmark); Balslev, Ingegerd [Department of Pathology, Copenhagen University Hospital at Herlev (Denmark); Logager, Vibeke [Department of Diagnostic Radiology, Copenhagen University Hospital at Herlev (Denmark); Hansen, Alastair [Department of Pathology, Copenhagen University Hospital at Herlev (Denmark); Jakobsen, Henrik; Kromann-Andersen, Bjarne; Norgaard, Nis [Department of Urology, Copenhagen University Hospital at Herlev, (Denmark); Horn, Thomas [Department of Pathology, Copenhagen University Hospital at Herlev (Denmark); Thomsen, Henrik S. [Department of Diagnostic Radiology, Copenhagen University Hospital at Herlev (Denmark)

    2011-11-15

    Purpose: To investigate diagnostic accuracy of detection of prostate cancer by magnetic resonance: to evaluate the performance of T2WI, DCEMRI and CSI and to correlate the results with biopsy and radical prostatectomy histopathological data. Materials and methods: 43 patients, scheduled for radical prostatectomy, underwent prostate MR examination. Prostate cancer was identified by transrectal ultrasonographically (TRUS) guided sextant biopsy. MR examination was performed at 1.5T with an endorectal MR coil. Cancer localisation was performed on sextant-basis - for comparison between TRUS biopsy, MR techniques and histopathological findings on prostatectomy specimens. Results: Prostate cancer was identified in all 43 patients by combination of the three MR techniques. The detection of prostate cancer on sextant-basis showed sensitivity and specificity: 50% and 91% for TRUS, 72% and 55% for T2WI, 49% and 69% for DCEMRI, and 46% and 78% for CSI. Conclusion: T2WI, DCEMRI and CSI in combination can identify prostate cancer. Further development of MR technologies for these MR methods is necessary to improve the detection of the prostate cancer.

  2. LF-15 & T7, synthetic peptides derived from tumstatin, attenuate aspects of airway remodelling in a murine model of chronic OVA-induced allergic airway disease.

    Karryn T Grafton

    Full Text Available BACKGROUND: Tumstatin is a segment of the collagen-IV protein that is markedly reduced in the airways of asthmatics. Tumstatin can play an important role in the development of airway remodelling associated with asthma due to its anti-angiogenic properties. This study assessed the anti-angiogenic properties of smaller peptides derived from tumstatin, which contain the interface tumstatin uses to interact with the αVβ3 integrin. METHODS: Primary human lung endothelial cells were exposed to the LF-15, T3 and T7 tumstatin-derived peptides and assessed for cell viability and tube formation in vitro. The impact of the anti-angiogenic properties on airways hyperresponsiveness (AHR was then examined using a murine model of chronic OVA-induced allergic airways disease. RESULTS: The LF-15 and T7 peptides significantly reduced endothelial cell viability and attenuated tube formation in vitro. Mice exposed to OVA+ LF-15 or OVA+T7 also had reduced total lung vascularity and AHR was attenuated compared to mice exposed to OVA alone. T3 peptides reduced cell viability but had no effect on any other parameters. CONCLUSION: The LF-15 and T7 peptides may be appropriate candidates for use as novel pharmacotherapies due to their small size and anti-angiogenic properties observed in vitro and in vivo.

  3. An Investigation into the Electromagnetic Interactions between a Superconducting Torus and Solenoid for the Jefferson Lab 12 GeV Upgrade

    Rajput-Ghoshal, Renuka [JLAB; Ghoshal, Probir K. [JLAB; Fair, Ruben J. [JLAB; Hogan, John P. [JLAB; Kashy, David H. [JLAB

    2015-06-01

    The Jefferson Lab 12 GeV Upgrade in Hall B will need CLAS12 detector that requires two superconducting magnets. One is a magnet system consisting of six superconducting trapezoidal racetrack-type coils assembled in a Toroidal configuration (Torus) and the second is an actively shielded solenoidal magnet (Solenoid). Both the torus and solenoid are located in close proximity to one another and are surrounded by sensitive detectors. This paper investigates the electromagnetic interactions between the two systems during normal operation as well as during various fault scenarios as part of a Risk Assessment and Mitigation (RAM).

  4. Pulsed thermoelectricity

    Apostol, M.; Nedelcu, M.

    2010-07-01

    A special mechanism of thermoelectric transport is described, consisting of pulses of charge carriers which "fly" periodically through the external circuit from the hot end of the sample to the cold end, with a determined duration of the "on" and "off" times of the electric contacts, while maintaining continuously the thermal contacts. It is shown that such a "resonant" ideal thermogenerator may work cyclically, with the same efficiency quotient as the ideal efficiency quotient of the thermoelectric devices operated in the usual stationary transport regime but the electric flow and power are increased, as a consequence of the concentration of the charge carriers on pulses of small spatial extent. The process is reversible, in the sense that it can be operated either as a thermoelectric generator or as an electrothermal cooler.

  5. Reproducibility of pulmonary blood flow measurements by phase-contrast MRI using different 1.5 T MR scanners at two institutions

    Iraha, Rin; Tsuchiya, Nanae; Yamashiro, Tsuneo; Iwasawa, Tae

    2017-01-01

    Background Magnetic resonance imaging (MRI) can be beneficial for diagnosis of disease by offering quantitative information. However, reproducibility can be a major problem when there is a numerical threshold in multi-institution, multi-vendor situations. Purpose To measure pulmonary blood flow with phase-contrast (PC) imaging using two different MR scanners (1.5 T) at different institutions in the same participants and to examine the reproducibility of the measurements. Material and Methods Participants were 10 healthy volunteers (5 men; age range, 27–36 years). The measurements included the mean and maximal blood velocities, the mean blood flow volume, and the acceleration time and volume (AT and AV), derived from the time-flow curve of the PC-MRI. Simultaneously obtained maximal, minimal, and mean areas from regions of interest set in the pulmonary artery were also calculated. In order to calculate the reproducibility of the quantitative variables, intra-class correlation coefficients (ICCs) were employed. When an adequate ICC was obtained, Bland–Altman analysis was conducted to identify any systematic bias. Results The ICCs were almost perfect for the mean blood flow volume and the AV (r = 0.82 and 0.80), and were substantial in the mean and maximal areas, and the AT (r = 0.63, 0.74, and 0.64, respectively). However, there was a fixed bias in the area measurement between the two scanners. Also, the AV had a proportional bias. Conclusion Our results reveal that various indices derived from PC-MRI on different MR scanners are promising as common indices for pulmonary flow assessment. Research and clinical use of PC-MRI for the pulmonary artery is expected to extend to multi-institution situations. PMID:28210495

  6. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    Yi, Ji Sook; Cha, Jang Gyu [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Han, Jong Kyu [Dept. of Radiology, Soonchunhyang University Cheonan Hospital, Cheonan (Korea, Republic of); Kim, Hyun Joo [Dept. of Radiology, Soonchunhyang University Seoul Hospital, Seoul (Korea, Republic of)

    2015-08-15

    To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.

  7. Orthodontic springs and auxiliary appliances: assessment of magnetic field interactions associated with 1.5 T and 3 T magnetic resonance systems

    Kemper, J.; Priest, A.N.; Adam, G. [University Medical Center of Hamburg-Eppendorf, Clinic of Diagnostic and Interventional Radiology, Hamburg (Germany); Schulze, D. [University Hospital of Freiburg, Department of Oral and Maxillofacial Surgery, Freiburg (Germany); Kahl-Nieke, B.; Klocke, A. [University Medical Center of Hamburg-Eppendorf, Department of Orthodontics, Hamburg (Germany)

    2007-02-15

    The objective of this paper is to evaluate magnetic field interactions at 1.5 and 3 T for 20 orthodontic devices used for fixed orthodontic therapy. Twenty springs and auxiliary parts made from varying ferromagnetic alloys were tested for magnetic field interactions in the static magnetic field at 1.5 and 3 T. Magnetic translational force F{sub z} (in millinewtons) was evaluated by determining the deflection angle {beta} [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force F{sub rot} was qualitatively determined using a five-point scale. {beta} was found to be >45 in 13(15) devices at 1.5(3) T and translational force F{sub z} exceeded gravitational force F{sub g} on the particular object [F{sub z} 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. F{sub z} was found to be up to 24.1(47.5)-fold higher than F{sub g} at 1.5(3) T. Corresponding to this, F{sub rot} on the objects was shown to be high at both field strengths ({>=} +3). Three objects (at 1.5 T) and one object (at 3 T) showed deflection angles <45 , but F{sub rot} was found to be {>=} +3 at both field strengths. For the remaining objects, {beta} was below 45 and torque measurements ranged from 0 to +2. Of 20 objects investigated for magnetic field interactions at 1.5(3) T, 13(15) were unsafe in magnetic resonance (MR), based on the ASTM criteria of F{sub z}. The implications of these results for orthodontic patients undergoing MRI are discussed. (orig.)

  8. Lactate and T{sub 2} measurements of synovial aspirates at 1.5 T: differentiation of septic from non-septic arthritis

    Wiener, Edzard; Zanetti, Marco; Hodler, Juerg; Pfirrmann, Christian W.A. [Orthopedic University Hospital Balgrist, Department of Radiology, Zurich (Switzerland)

    2008-08-15

    The aim of this study was to differentiate septic from non-septic arthritis by measuring lactate concentration with {sup 1}H magnetic resonance spectroscopy (HMRS) and by estimating total protein content with the assessment of T{sub 2} values. In 30 patients with acute arthritis, synovial fluid was aspirated. Lactate concentrations were analyzed with single voxel HMRS at 1.5 T. T{sub 2} relaxation times were mapped with a multi-spin echo sequence. All samples underwent microbiological testing and routine laboratory analysis to quantify lactate concentration and total protein content. Values obtained in septic and non-septic arthritis were compared with a Mann-Whitney U test. Synovial fluid from patients with septic arthritis (n=10) had higher concentrations of lactate (11.4 {+-} 4.0 mmol/L) and higher total protein content (51.8 {+-} 10.7 g/L) than fluid obtained in non-septic arthritis (n=20; 5.2{+-}1.1 mmol/L and 40.4{+-}6.9 g/L, respectively, p < 0.001 and <0.01, respectively). Measured lactate concentrations and T{sub 2} relaxation times (as an indicator of total protein content) were moderately correlated to laboratory-confirmed lactate concentration (r{sup 2}=0.71) and total protein content (r{sup 2}=0.73). Markedly increased lactate concentrations (>6 mmol/L) in combination with low T{sub 2} values (<550 ms) identify septic arthritis with a sensitivity of 70% and a specificity of 89%. Spectroscopic measurements of lactate concentration in combination with the estimation of protein content using T{sub 2} may be of value in the differentiation of septic from non-septic arthritis. (orig.)

  9. Polyethylene glycol-covered ultra-small Gd2O3 nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning

    Fortin, Marc-André; Petoral, Rodrigo M., Jr.; Söderlind, Fredrik; Klasson, A.; Engström, Maria; Veres, Teodor; Käll, Per-Olof; Uvdal, Kajsa

    2007-10-01

    The size distribution and magnetic properties of ultra-small gadolinium oxide crystals (US-Gd2O3) were studied, and the impact of polyethylene glycol capping on the relaxivity constants (r1, r2) and signal intensity with this contrast agent was investigated. Size distribution and magnetic properties of US-Gd2O3 nanocrystals were measured with a TEM and PPMS magnetometer. For relaxation studies, diethylene glycol (DEG)-capped US-Gd2O3 nanocrystals were reacted with PEG-silane (MW 5000). Suspensions were adequately dialyzed in water to eliminate traces of Gd3+ and surfactants. The particle hydrodynamic radius was measured with dynamic light scattering (DLS) and the proton relaxation times were measured with a 1.5 T MRI scanner. Parallel studies were performed with DEG-Gd2O3 and PEG-silane-SPGO (Gd2O3,PEG-silane-US-Gd2O3 relaxation parameters were twice as high as for Gd-DTPA and the r2/r1 ratio was 1.4. PEG-silane-SPGO gave low r1 relaxivities and high r2/r1 ratios, less compatible with positive contrast agent requirements. Higher r1 were obtained with PEG-silane in comparison to DEG-Gd2O3. Treatment of DEG-US-Gd2O3 with PEG-silane provides enhanced relaxivity while preventing aggregation of the oxide cores. This study confirms that PEG-covered Gd2O3 nanoparticles can be used for positively contrasted MR applications requiring stability, biocompatible coatings and nanocrystal functionalization.

  10. Unbiased ascertainment of a patient with a 47,XY, +pseudic (15)t(15;15)(q13;q13) karyotype by amniocentesis

    Spector, E.; Prochazka, G.; Hamilton, S. [Univ. of Colorado School of Medicine, Denver (United States)] [and others

    1994-09-01

    A 47,XY,+mar male karyotype was found in all metaphases on an amniocentesis from a 36-year-old woman (G1,P0). The marker was G group size. Chromosome studies on the parents were normal. C-banding, NOR staining and FISH demonstrated that the marker was dicentric, bisatellited, derived from No. 15 and contained 2 copies of the chromosomal region flanked by the Prader-Willi/Angelman A and B probes. The final karyotype was: 47,XY,+pseudic(15)t(15;15)(q13;q13), making the fetus tetrasomic for the genes in the duplicated region. DNA marker studies for No. 15 (performed in the laboratory of Dr. David Ledbetter) revealed that the fetus had inherited on No. 15 from each parent and that the marker was derived from both maternal No. 15 chromosomes. The parents chose to continue the pregnancy. The baby was born at 38 weeks gestation, was mildly edematous and had Apgar scores of 4, 7, and 8 at 1, 5, and 10 min, respectively. The marker was confirmed to be present in placenta and the baby`s blood. Examination at 6 weeks showed appropriate growth and development. Data from published cases predict that this baby will be mentally retarded and may have seizures because he is tetrasomic for 15pter-q13, but will not have Prader-Willi or Angelman syndromes since he has biparental inheritance of his normal No. 15s. However, the published cases may represent a biased sample as most were identified in mentally retarded individuals, not by prenatal diagnosis. This infant`s development will continue to be followed closely.

  11. Quantitative and qualitative comparison of 0.025 mmol/kg gadobenate dimeglumine for abdominal MRI at 1.5 T and 3 T MRI in patients with low estimated glomerular filtration rate

    Ramalho, Miguel; AlObaidy, Mamdoh; Busireddy, Kiran K.; Altun, Ersan; Liu, Baodong; Semelka, Richard C., E-mail: richsem@med.unc.edu

    2015-01-15

    Highlights: • Efficacy and adequacy of enhancement using quarter dose gadobenate dimeglumine at 1.5 T was studied in patients with low GFR. • A dose of 0.025 mmol/kg of gadobenate dimeglumine at 1.5 T showed diagnostic enhancement quality in the majority of patients. • There were no significant differences between the qualitative perception of enhancement between 1.5 T and 3 T. • Patients who have renal impairment may still be able to receive GBCAs, while maintaining adequate enhancement at 1.5 T. - Abstract: Purpose: To investigate the efficacy and adequacy of enhancement employing 0.025 mmol/kg of gadobenate dimeglumine at 1.5 Tesla (T), and to compare the extent of enhancement of this dosage between 1.5 T and 3 T systems. Materials and methods: Our final population included 116 consecutive patients who underwent 0.025 mmol/kg gadobenate dimeglumine-enhanced abdominal MRI (78 men and 38 women; age, 64.1 ± 13.6 years). Sixty patients underwent imaging at 1.5 T and 56 patients underwent imaging at 3 T. Abdominal enhancement was evaluated qualitatively and quantitatively. The quality of enhancement was compared using Mann–Whitney U test. The percentage of enhancement of each organ was compared using Student t-test. Results: The mean quality rating of enhancement was at least “good” in all phases of enhancement for both 1.5 T and 3 T. There was a non-significant trend to higher mean ratings at 3 T. The liver showed a 1.3-fold higher arterial-phase percentage of enhancement at 3 T (p = 0.0138). There were no differences between the mean relative enhancement of the pancreas and aorta throughout all phases of enhancement. The percentage of enhancement of the renal cortex was significantly higher at 3 T (p < 0.0001 to p = 0.0293). Conclusion: A dose of 0.025 mmol/kg of gadobenate dimeglumine demonstrates diagnostic enhancement in the majority of patients at 1.5 T, without significant differences on qualitative evaluation compared to 3 T.

  12. PULSE COLUMN

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  13. INDUCTION HEATING OF NON-MAGNETIC SHEET METALS IN THE FIELD OF A FLAT CIRCULAR MULTITURN SOLENOID

    Y. Batygin

    2016-06-01

    Full Text Available The theoretical analysis of electromagnetic processes in the system for induction heating presented by a flat circular multiturn solenoid positioned above a plane of thin sheet non-magnetic metal has been conducted. The calculated dependences for the current induced in a metal sheet blank and ratio of transformation determined have been obtained. The maximal value of the transformation ratio with regard to spreading the eddy-currents over the whole area of the sheet metal has been determined.

  14. Plasma column development in the CO2 laser-heated solenoid

    Tighe, W.; Offenberger, A. A.; Capjack, C. E.

    1987-08-01

    Axial and radial plasma dynamics in the CO2 laser-heated solenoid have been studied experimentally and numerically. The axial behavior is found to be well described by a self-regulated bleaching wave model. The radial expansion is found to be strongly dependent on the focusing ratio of the input laser beam. With a fast focus ( f/5), the early radial expansion rate is twice that found with a slower focusing arrangement ( f/15). The faster focusing ratio also results in a significantly wider plasma column. On the other hand, no significant dependence of f/♯ on the axial propagation was found. A finite ionization time and the rapid formation of a density minimum on axis are observed and verify earlier experimental results. Detailed comparisons are made with a 2-D magnetohydrodynamic (MHD) and laser propagation code. The axial and radial plasma behavior and, in particular, the dependence of the radial behavior on the focal ratio of the laser are reasonably well supported by the simulation results. Computational results are also in good agreement with experimental measurements of temperature and density using stimulated scattering (Brillouin, Raman) and interferometry diagnostic techniques.

  15. Tor forms a dimer through an N-terminal helical solenoid with a complex topology.

    Baretić, Domagoj; Berndt, Alex; Ohashi, Yohei; Johnson, Christopher M; Williams, Roger L

    2016-04-13

    The target of rapamycin (Tor) is a Ser/Thr protein kinase that regulates a range of anabolic and catabolic processes. Tor is present in two complexes, TORC1 and TORC2, in which the Tor-Lst8 heterodimer forms a common sub-complex. We have determined the cryo-electron microscopy (EM) structure of Tor bound to Lst8. Two Tor-Lst8 heterodimers assemble further into a dyad-symmetry dimer mediated by Tor-Tor interactions. The first 1,300 residues of Tor form a HEAT repeat-containing α-solenoid with four distinct segments: a highly curved 800-residue N-terminal 'spiral', followed by a 400-residue low-curvature 'bridge' and an extended 'railing' running along the bridge leading to the 'cap' that links to FAT region. This complex topology was verified by domain insertions and offers a new interpretation of the mTORC1 structure. The spiral of one TOR interacts with the bridge of another, which together form a joint platform for the Regulatory Associated Protein of TOR (RAPTOR) regulatory subunit.

  16. Development of a solenoid pumped in situ zinc analyzer for environmental monitoring

    Chapin, T.P.; Wanty, R.B.

    2005-01-01

    A battery powered submersible chemical analyzer, the Zn-DigiScan (Zn Digital Submersible Chemical Analyzer), has been developed for near real-time, in situ monitoring of zinc in aquatic systems. Microprocessor controlled solenoid pumps propel sample and carrier through an anion exchange column to separate zinc from interferences, add colorimetric reagents, and propel the reaction complex through a simple photometric detector. The Zn-DigiScan is capable of self-calibration with periodic injections of standards and blanks. The detection limit with this approach was 30 ??g L-1. Precision was 5-10% relative standard deviation (R.S.D.) below 100 ??g L-1, improving to 1% R.S.D. at 1000 ??g L-1. The linear range extended from 30 to 3000 ??g L-1. In situ field results were in agreement with samples analyzed by inductively coupled plasma mass spectrometry (ICPMS). This pump technology is quite versatile and colorimetric methods with complex online manipulations such as column reduction, preconcentration, and dilution can be performed with the DigiScan. However, long-term field deployments in shallow high altitude streams were hampered by air bubble formation in the photometric detector. ?? 2005 Elsevier B.V. All rights reserved.

  17. Design and Construction of a Prototype Solenoid Coil for MICE Coupling Magnets

    Wang, Li; Pan, Heng; Guo, XingLong; Xu, FengYu; Liu, XiaoKun; Wu, Hong; Zheng, ShiXian; Green, Michael A; Li, Derun; Virostek, Steve; Zisman, Michael

    2010-06-28

    A superconducting coupling solenoid mounted around four conventional RF cavities, which produces up to 2.6 T central magnetic field to keep the muons within the cavities, is to be used for the Muon Ionization Cooling Experiment (MICE). The coupling coil made from copper matrix NbTi conductors is the largest of three types of magnets in MICE both in terms of 1.5 m inner diameter and about 13MJ stored magnetic energy at full operation current of 210A. The stress induced inside the coil assembly during cool down and magnet charging is relatively high. In order to validate the design method and develop the coil winding technique with inside-wound SC splices required for the coupling coil, a prototype coil made from the same conductor and with the same diameter and thickness but only one-fourth long as the coupling coil was designed and fabricated by ICST. The prototype coil was designed to be charged to strain conditions that are equivalent or greater than would be encountered in the coupling coil. This paper presents detailed design of the prototype coil as well as developed coil winding skills. The analyses on stress in the coil assembly and quench process were carried out.

  18. Thermal Stability of Large Al-stabilized Superconducting Magnets Theoritical Analysis of CMS Solenoid.

    Juster, F P

    1998-01-01

    The CMS detector magnet presently under design for the future Large Hadron Collider at CERN is an epoxy-impregnated structure, indirectly cooled by two-phase flow liquid helium. This magnet, based on aluminum-stabilized, mechanically reinforced conductor, is not cryostable : the heat generated by a thermal disturbance can be removed only by thermal diffusivity through the windings. In order to study the thermal stability of the magnet, we have developed numerical codes able to predict the thermal behaviour of an anisotropic and non-homogeneous medium against thermal perturbations due to friction or epoxy cracking. Our 3D finite element codes can calculate the propagation or the recovery of a normal zone in a superconducting magnet, taking into account the current diffusion effect, which strongly affects the heat generated by a transition in the case of large Al-stabilized conductors. Two different codes, CASTEM 2000 and HEATING are described in this paper. We present the results of the CMS Solenoid magnet sta...

  19. Simulator for the Parity-Violating Deep Inelastic Scattering experiment in the Solenoidal Large Intensity Detector

    Anderson, Jack; Hall A SoLID Collaboration

    2013-10-01

    The Solenoid Large Intensity Detector (SoLID) particle detector is the main detector that will be used for high energy particle experiments in Hall A that will be used with the 12 GeV electron beam at the Jefferson Lab. SoLID geometries were writen to be implemented in Geant4 using openGL as the visualization tool. This will allow us to test how the calorimeter, a specific yet integral part of the SoLID detector, detects the particles that result from electron beams colliding with targets. The goal is to simulate the approved experiments for the SoLID detector, starting with the Parity-Violating Deep Inelastic Scattering (PVDIS) experiment. This will provide critical information regarding the effectiveness of the calorimeter's design for such experiments. The expectation is that a Shashlik calorimeter will prove effective for the experiments approved for the SoLID detector. The ideal number of layers, or types of material for said layers, is an aspect of the calorimeter that will require testing through the simulations.The geometry files allow an easily-packaged program that can be shared amongst any collaborators interested in the SoLID experiments. NSF Grant No. 714001.

  20. Overview of Non-Solenoidal Startup Studies in the Pegasus ST

    Bongard, M. W.; Barr, J. L.; Bodner, G. M.; Burke, M. G.; Fonck, R. J.; Pachicano, J. L.; Perry, J. M.; Reusch, J. A.; Richner, N. J.; Rodriguez Sanchez, C.; Schlossberg, D. J.

    2016-10-01

    Local helicity injection (LHI) is a non-solenoidal startup method pursued on Pegasus utilizing compact, high power current sources (Ainj 2 - 4 cm2, Iinj 10 kA, Vinj 1 kV) at the plasma edge. Outboard injectors (Ninj = 4 , Ainj = 8 cm2) produce Ip 170 kA plasmas compatible with Ohmic drive. A 0-D model that treats the plasma as a resistive element with time-varying inductance and enforces Ip limits from Taylor relaxation is used to interpret experimental Ip(t) in several scenarios. Strong inductive drive arises from the plasma shape evolution, in addition to poloidal field induction. A new injector system has recently been installed in the lower divertor region (Ninj = 2 , Ainj = 8 cm2) to explore the implications of geometric placement of the helicity injectors on LHI startup. This geometry supports tests of reconnection dynamics seen in NIMROD simulations, high-BT effects expected in larger devices, and LHI electron confinement with and without inductive assist. Plasmas with Ip > 130 kA, Vinj 0.5 kV, Δtpulse 8 ms and BT /BT , max = 100 eV during LHI, suggesting the confinement is not strongly stochastic. Conceptual design work is exploring the feasibility of coaxial helicity injection and ECH heating on Pegasus in addition to LHI. Work supported by US DOE Grant DE-FG02-96ER54375.

  1. Tor forms a dimer through an N-terminal helical solenoid with a complex topology

    Baretić, Domagoj; Berndt, Alex; Ohashi, Yohei; Johnson, Christopher M.; Williams, Roger L.

    2016-04-01

    The target of rapamycin (Tor) is a Ser/Thr protein kinase that regulates a range of anabolic and catabolic processes. Tor is present in two complexes, TORC1 and TORC2, in which the Tor-Lst8 heterodimer forms a common sub-complex. We have determined the cryo-electron microscopy (EM) structure of Tor bound to Lst8. Two Tor-Lst8 heterodimers assemble further into a dyad-symmetry dimer mediated by Tor-Tor interactions. The first 1,300 residues of Tor form a HEAT repeat-containing α-solenoid with four distinct segments: a highly curved 800-residue N-terminal 'spiral', followed by a 400-residue low-curvature 'bridge' and an extended `railing' running along the bridge leading to the 'cap' that links to FAT region. This complex topology was verified by domain insertions and offers a new interpretation of the mTORC1 structure. The spiral of one TOR interacts with the bridge of another, which together form a joint platform for the Regulatory Associated Protein of TOR (RAPTOR) regulatory subunit.

  2. Final design of the Switching Network Units for the JT-60SA Central Solenoid

    Lampasi, Alessandro, E-mail: alessandro.lampasi@enea.it [National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Frascati (Italy); Coletti, Alberto; Novello, Luca [Fusion for Energy (F4E) Broader Fusion Development Department, Garching (Germany); Matsukawa, Makoto [Japan Atomic Energy Agency, Naka Fusion Institute, Mukouyama, Naka-si, Ibaraki-ken (Japan); Burini, Filippo; Taddia, Giuseppe; Tenconi, Sandro [OCEM Energy Technology, San Giorgio Di Piano (Italy)

    2014-04-15

    This paper describes the approved detailed design of the four Switching Network Units (SNUs) of the superconducting Central Solenoid of JT-60SA, the satellite tokamak that will be built in Naka, Japan, in the framework of the “Broader Approach” cooperation agreement between Europe and Japan. The SNUs can interrupt a current of 20 kA DC in less than 1 ms in order to produce a voltage of 5 kV. Such performance is obtained by inserting an electronic static circuit breaker in parallel to an electromechanical contactor and by matching and coordinating their operations. Any undesired transient overvoltage is limited by an advanced snubber circuit optimized for this application. The SNU resistance values can be adapted to the specific operation scenario. In particular, after successful plasma breakdown, the SNU resistance can be reduced by a making switch. The design choices of the main SNU elements are justified by showing and discussing the performed calculations and simulations. In most cases, the developed design is expected to exceed the performances required by the JT-60SA project.

  3. Development of a solenoid actuated planar valveless micropump with single and multiple inlet-outlet arrangements

    Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.

    2016-07-01

    We report a planar solenoid actuated valveless micropump with multiple inlet-outlet configurations. The self-priming characteristics of the multiple inlet-multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet-multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet-two outlet micropump provides a maximum flow rate of 336 μl min-1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet-two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.

  4. Test of the ITER TF Insert and Central Solenoid Model Coil

    Martovetsky, N; Takayasu, M; Minervini, J; Isono, T; Sugimoto, M; Kato, T; Kawano, K; Koisumi, N; Nakajima, H; Nunova, Y; Okuno, K; Tsuji, H; Oshikiri, M; Mitchell, N; Takahashi, Y; Egorov, S; Rodin, I; Zanino, R; Savoldi, L

    2002-07-29

    The Central Solenoid Model Coil (CSMC) was designed and built by ITER collaboration between the European Union, Japan, Russian Federation and the United States in 1993-2001. Three heavily instrumented insert coils have been also built for testing in the background field of the CSMC to cover a wide operational space. The TF Insert was designed and built by the Russian Federation to simulate the conductor performance under the ITER TF coil conditions. The TF Insert Coil was tested in the CSMC Test Facility at the Japan Atomic Energy Research Institute, Naka, Japan in September-October 2001. Some measurements were performed also on the CSMC to study effects of electromagnetic and cooldown cycles. The TF Insert coil was charged successfully, without training, in the background field of the CSMC to the design current of 46 kA at 13 T peak field. The TF Insert met or exceeded all design objectives, however some interesting results require thorough analyses. This paper presents the overview of main results of the testing--magnet critical parameters, ac losses, joint performance, effect of cycles on performance, quench and thermo-hydraulic characteristics and some results of the post-test analysis.

  5. Test of the ITER Central Solenoid Model Coil and CS Insert

    Martovetsky, N; Michael, P; Minervini, J; Radovinsky, A; Takayasu, M; Gung, C Y; Thome, R; Ando, T; Isono, T; Hamada, K; Kato, T; Kawano, K; Koizumi, N; Matsui, K; Nakajima, H; Nishijima, G; Nunoya, Y; Sugimoto, M; Takahasi, Y; Hsuji, H; Bessette, D; Okuno, K; Mitchell, N; Ricci, M; Zanino, R; Savoldi, L; Arai, K; Ninomiya, A

    2001-09-25

    The Central Solenoid Model Coil (CSMC) was designed and built from 1993 to 1999 by an ITER collaboration between the US and Japan, with contributions from the European Union and the Russian Federation. The main goal of the project was to establish the superconducting magnet technology necessary for a large-scale fusion experimental reactor. Three heavily instrumented insert coils were built to cover a wide operational space for testing. The CS Insert, built by Japan, was tested in April-August of 2000. The TF Insert, built by Russian Federation, will be tested in the fall of 2001. The NbAl Insert, built by Japan, will be tested in 2002. The testing takes place in the CSMC Test Facility at the Japan Atomic Energy Research Institute, Naka, Japan. The CSMC was charged successfully without training to its design current of 46 kA to produce 13 T in the magnet bore. The stored energy at 46 kA was 640 MJ. This paper presents the main results of the CSMC and the CS Insert testing--magnet critical parameters, ac losses, joint performance, quench characteristics and some results of the post-test analysis.

  6. Modeling H2 formation in the turbulent ISM: Solenoidal versus compressive turbulent forcing

    Milosavljevic, Milica; Federrath, Christoph; Klessen, Ralf S

    2011-01-01

    We present results from high-resolution three-dimensional simulations of the turbulent interstellar medium that study the influence of the nature of the turbulence on the formation of molecular hydrogen. We have examined both solenoidal (divergence-free) and compressive (curl-free) turbulent driving, and show that compressive driving leads to faster H2 formation, owing to the higher peak densities produced in the gas. The difference in the H2 formation rate can be as much as an order of magnitude at early times, but declines at later times as the highest density regions become fully molecular and stop contributing to the total H2 formation rate. We have also used our results to test a simple prescription suggested by Gnedin et al. (2009) for modeling the influence of unresolved density fluctuations on the H2 formation rate in large-scale simulations of the ISM. We find that this approach works well when the H2 fraction is small, but breaks down once the highest density gas becomes fully molecular.

  7. Thermal analysis of the cold mass of the 2T solenoid for the PANDA detector at FAIR

    Rolando, G.; ten Kate, H. H. J.; Dudarev, A.; Pais Da Silva, H.; Vodopyanov, A.; Schmitt, L.

    2015-12-01

    The superconducting solenoid of the PANDA experiment at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt (Germany) is designed to provide a magnetic field of 2 T over a length of about 4 m in a bore of 1.9 m. To allow a warm target feed pipe oriented transversely to the solenoid axis and penetrating through the cryostat and solenoid cold mass, the magnet is split into 3 inter-connected coils fitted in a common support cylinder. During normal operation, cooling of the cold mass to the working temperature of 4.5 K will be achieved through the circulation by natural convection of two-phase helium in cooling pipes attached to the Al-alloy support cylinder. Pure aluminium strips acting as heat drains and glued to the inner surface of the three coils and thermally bonded to the cooling pipes allow minimizing the temperature gradient across the 6-layers coils. In this paper the thermal design of the cold mass during normal operation and current ramps up and down is validated using an analytical approximation and numerical simulation.

  8. Thermal analysis of the cold mass of the 2T solenoid for the PANDA detector at FAIR

    Rolando, G; Dudarev, A; Pais Da Silva, H; Vodopyanov, A; Schmitt, L

    2015-01-01

    The superconducting solenoid of the PANDA experiment at the Facility for Antiproton and Ion Research (FAIR) in Darmstadt (Germany) is designed to provide a magnetic field of 2 T over a length of about 4 m in a bore of 1.9 m. To allow a warm target feed pipe oriented transversely to the solenoid axis and penetrating through the cryostat and solenoid cold mass, the magnet is split into 3 inter-connected coils fitted in a common support cylinder. During normal operation, cooling of the cold mass to the working temperature of 4.5 K will be achieved through the circulation by natural convection of two-phase helium in cooling pipes attached to the Al-alloy support cylinder. Pure aluminium strips acting as heat drains and glued to the inner surface of the three coils and thermally bonded to the cooling pipes allow minimizing the temperature gradient across the 6-layers coils. In this paper the thermal design of the cold mass during normal operation and current ramps up and down is validated using an analytical appro...

  9. Restricted mobility of side chains on concave surfaces of solenoid proteins may impart heightened potential for intermolecular interactions.

    Ramya, L; Gautham, N; Chaloin, Laurent; Kajava, Andrey V

    2015-09-01

    Significant progress has been made in the determination of the protein structures with their number today passing over a hundred thousand structures. The next challenge is the understanding and prediction of protein-protein and protein-ligand interactions. In this work we address this problem by analyzing curved solenoid proteins. Many of these proteins are considered as "hub molecules" for their high potential to interact with many different molecules and to be a scaffold for multisubunit protein machineries. Our analysis of these structures through molecular dynamics simulations reveals that the mobility of the side-chains on the concave surfaces of the solenoids is lower than on the convex ones. This result provides an explanation to the observed preferential binding of the ligands, including small and flexible ligands, to the concave surface of the curved solenoid proteins. The relationship between the landscapes and dynamic properties of the protein surfaces can be further generalized to the other types of protein structures and eventually used in the computer algorithms, allowing prediction of protein-ligand interactions by analysis of protein surfaces.

  10. Comparison of left ventricular function assessment using phonocardiogram- and electrocardiogram-triggered 2D SSFP CINE MR imaging at 1.5 T and 3.0 T

    Becker, Meike [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Humboldt-University, Experimental and Clinical Research Center (ECRC), Charite Campus Buch, Berlin (Germany); Frauenrath, Tobias; Hezel, Fabian [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin (Germany); Krombach, Gabriele A.; Kremer, Ute; Koppers, Benedikt [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Butenweg, Christoph; Goemmel, Andreas [Chair of Structural Statics and Dynamics, RWTH Aachen, Aachen (Germany); Utting, Jane F. [MRI, NHS Grampian, Aberdeen Royal Infirmary, Aberdeen (United Kingdom); Schulz-Menger, Jeanette [Humboldt-University, Working Group Cardiovascular MR, Franz-Volhard-Klinik, Department of Cardiology, HELIOS-Klinikum Berlin-Buch and Charite Campus Buch, Berlin (Germany); Niendorf, Thoralf [University Hospital, RWTH Aachen, Department of Diagnostic Radiology, Aachen (Germany); Humboldt-University, Experimental and Clinical Research Center (ECRC), Charite Campus Buch, Berlin (Germany); Berlin Ultrahigh Field Facility, Max-Delbrueck Center for Molecular Medicine, Berlin (Germany)

    2010-06-15

    As high-field cardiac MRI (CMR) becomes more widespread the propensity of ECG to interference from electromagnetic fields (EMF) and to magneto-hydrodynamic (MHD) effects increases and with it the motivation for a CMR triggering alternative. This study explores the suitability of acoustic cardiac triggering (ACT) for left ventricular (LV) function assessment in healthy subjects (n = 14). Quantitative analysis of 2D CINE steady-state free precession (SSFP) images was conducted to compare ACT's performance with vector ECG (VCG). Endocardial border sharpness (EBS) was examined paralleled by quantitative LV function assessment. Unlike VCG, ACT provided signal traces free of interference from EMF or MHD effects. In the case of correct R-wave recognition, VCG-triggered 2D CINE SSFP was immune to cardiac motion effects - even at 3.0 T. However, VCG-triggered 2D SSFP CINE imaging was prone to cardiac motion and EBS degradation if R-wave misregistration occurred. ACT-triggered acquisitions yielded LV parameters (end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and left ventricular mass (LVM)) comparable with those derived from VCG-triggered acquisitions (1.5 T: ESV{sub VCG} = (56 {+-} 17) ml, EDV{sub VCG} = (151 {+-} 32) ml, LVM{sub VCG} = (97 {+-} 27) g, SV{sub VCG} = (94 {+-} 19) ml, EF{sub VCG} = (63 {+-} 5)% cf. ESV{sub ACT} = (56 {+-} 18) ml, EDV{sub ACT} = (147 {+-} 36) ml, LVM{sub ACT} = (102 {+-} 29) g, SV{sub ACT} = (91 {+-} 22) ml, EF{sub ACT} = (62 {+-} 6)%; 3.0 T: ESV{sub VCG} = (55 {+-} 21) ml, EDV{sub VCG} = (151 {+-} 32) ml, LVM{sub VCG} = (101 {+-} 27) g, SV{sub VCG} = (96 {+-} 15) ml, EF{sub VCG} = (65 {+-} 7)% cf. ESV{sub ACT} = (54 {+-} 20) ml, EDV{sub ACT} = (146 {+-} 35) ml, LVM{sub ACT} = (101 {+-} 30) g, SV{sub ACT} = (92 {+-} 17) ml, EF{sub ACT} = (64 {+-} 6)%). ACT's intrinsic insensitivity to interference from electromagnetic fields renders it suitable for clinical CMR. (orig.)

  11. Polyethylene glycol-covered ultra-small Gd{sub 2}O{sub 3} nanoparticles for positive contrast at 1.5 T magnetic resonance clinical scanning

    Fortin, Marc-Andre [Unite de Bioingenerie et de Biotechnologie, Centre Hospitalier Universitaire de Quebec (CHUQ) and Laval University, QC, G1K 7P4 (Canada); Jr, Rodrigo M Petoral [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-58183 Linkoeping (Sweden); Soederlind, Fredrik [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-58183 Linkoeping (Sweden); Klasson, A [Center for Medical Image Science and Visualization (CMIV), Linkoeping University/US, SE-58185 Linkoeping (Sweden); Engstroem, Maria [Center for Medical Image Science and Visualization (CMIV), Linkoeping University/US, SE-58185 Linkoeping (Sweden); Veres, Teodor [National Research Council of Canada (CNRC-IMI) 75, boulevard de Mortagne, Boucherville, QC, J4B 6Y4 (Canada); Kaell, Per-Olof [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-58183 Linkoeping (Sweden); Uvdal, Kajsa [Department of Physics, Chemistry and Biology (IFM), Linkoeping University, SE-58183 Linkoeping (Sweden)

    2007-10-03

    The size distribution and magnetic properties of ultra-small gadolinium oxide crystals (US-Gd{sub 2}O{sub 3}) were studied, and the impact of polyethylene glycol capping on the relaxivity constants (r{sub 1}, r{sub 2}) and signal intensity with this contrast agent was investigated. Size distribution and magnetic properties of US-Gd{sub 2}O{sub 3} nanocrystals were measured with a TEM and PPMS magnetometer. For relaxation studies, diethylene glycol (DEG)-capped US-Gd{sub 2}O{sub 3} nanocrystals were reacted with PEG-silane (MW 5000). Suspensions were adequately dialyzed in water to eliminate traces of Gd{sup 3+} and surfactants. The particle hydrodynamic radius was measured with dynamic light scattering (DLS) and the proton relaxation times were measured with a 1.5 T MRI scanner. Parallel studies were performed with DEG-Gd{sub 2}O{sub 3} and PEG-silane-SPGO (Gd{sub 2}O{sub 3},< 40 nm diameter). The small and narrow size distribution of US-Gd{sub 2}O{sub 3} was confirmed with TEM ({approx}3 nm) and DLS. PEG-silane-US-Gd{sub 2}O{sub 3} relaxation parameters were twice as high as for Gd-DTPA and the r{sub 2}/r{sub 1} ratio was 1.4. PEG-silane-SPGO gave low r{sub 1} relaxivities and high r{sub 2}/r{sub 1} ratios, less compatible with positive contrast agent requirements. Higher r{sub 1} were obtained with PEG-silane in comparison to DEG-Gd{sub 2}O{sub 3}. Treatment of DEG-US-Gd{sub 2}O{sub 3} with PEG-silane provides enhanced relaxivity while preventing aggregation of the oxide cores. This study confirms that PEG-covered Gd{sub 2}O{sub 3} nanoparticles can be used for positively contrasted MR applications requiring stability, biocompatible coatings and nanocrystal functionalization.

  12. Field strength in MR imaging of multiple sclerosis: A comparison of 0. 5 and 1. 5 T. Bedeutung der Magnetfeldstaerke in der MR-Diagnostik der multiplen Sklerose: Ein Vergleich von 0,5 und 1,5 T

    Schima, W. (Universitaetsklinik fuer Radiodiagnostik und MR-Institut der Medizinischen Fakultaet, Vienna (Austria)); Wimberger, D. (Universitaetsklinik fuer Radiodiagnostik und MR-Institut der Medizinischen Fakultaet, Vienna (Austria)); Schneider, B. (Institut fuer Medizinische Statistik, Univ. Vienna (Austria)); Stiglbauer, R. (Universitaetsklinik fuer Radiodiagnostik und MR-Institut der Medizinischen Fakultaet, Vienna (Austria)); Asenbaum, S. (Universitaetsklinik fuer Neurologie, Vienna (Austria)); Imhof, H. (Universitaetsklinik fuer Radiodiagnostik und MR-Institut der Medizinischen Fakultaet, Vienna (Austria))

    1993-04-01

    The value of magnetic resonance (MR) to establish the diagnosis of multiple sclerosis (MS) is well known. This study was undertaken to compare MR imaging of the brain of MS patients at high (1.5 T) and mid (0.5 T) field strength. 25 patients with MS underwent two consecutive MR studies within one hour, each consisting of axial proton density and T[sub 2]-weighted spin-echo images. Lesions in the supratentorial white matter and corpus callosum and those in the brain stem and cerebellum were separately counted. At 1.5 T significantly more lesions were seen than at 0.5 T (p<0.05). Although T[sub 2]-weighted images at 1.5 T added significant information compared to images obtained at 0.5 T, in none of our 25 patients the diagnosis was missed at 0.5 T. However, at 1.5 T dissemination in space was better demonstrated, suggesting MR scanning with high field-units to be favourable in patients with clinically suspected MS. (orig.)

  13. The AC loss evaluation of central solenoid model coil for CFETR

    Shi, Yi, E-mail: shiyi@ipp.ac.cn; Wu, Yu; Hao, QiangWang; Liu, Bo; Yang, Yilin

    2016-06-15

    Highlights: • In this study, The AC loss of CFETR CSMC is calculated. • The main AC losses type and mechanics of CFETR CSMC are introduced, where the hysteresis and coupling loss of Nb{sub 3}Sn and NbTi coil are estimated. • The low frequency eddy current loss calculation of stainless steel structural components is carried out by ANSYS with 3-D separate model. • In the case of conductor joints, a 3-D ANSYS code is also used to obtain the eddy current losses for the metal components. - Abstract: The AC loss of Central Solenoid Model Coil (CSMC) of China Fusion Engineering Test Reactor (CFETR) is calculated in order to be able to determine the allowable excitation current shape in time with respect to the available cooling capacity at liquid helium temperature. Firstly, the structure and operation parameters of CFETR CSMC are summarized including the superconductor, conductor and magnetic field distribution characteristic. Secondly, the main AC losses type and mechanics of CFETR CSMC are introduced, where the hysteresis and coupling loss of Nb{sub 3}Sn and NbTi coil are estimated using of the model data and a calculation flux density distribution in the cross-section of model coil by ANSYS 2-D model. Thirdly, the low frequency eddy current loss calculation of stainless steel structural components is carried out by ANSYS/EMAG code with 3-D separately for tension rods, plates and beams model. The interaction between several components is not considered. In the case of conductor joints, a 3-D ANSYS code is also used with current force to obtain the eddy current losses for the metal components. Lastly, the individual loss components are summed up. The significant conclusions are made which can provide the valuable guidance for safe operation of CSMC.

  14. Capture and Transport of Laser Accelerated Protons by Pulsed Magnetic Fields: Advancements Toward Laser-Based Proton Therapy

    Burris-Mog, Trevor J.

    The interaction of intense laser light (I > 10 18 W/cm2) with a thin target foil leads to the Target Normal Sheath Acceleration mechanism (TNSA). TNSA is responsible for the generation of high current, ultra-low emittance proton beams, which may allow for the development of a compact and cost effective proton therapy system for the treatment of cancer. Before this application can be realized, control is needed over the large divergence and the 100% kinetic energy spread that are characteristic of TNSA proton beams. The work presented here demonstrates control over the divergence and energy spread using strong magnetic fields generated by a pulse power solenoid. The solenoidal field results in a parallel proton beam with a kinetic energy spread DeltaE/E = 10%. Assuming that next generation lasers will be able to operate at 10 Hz, the 10% spread in the kinetic energy along with the 23% capture efficiency of the solenoid yield enough protons per laser pulse to, for the first time, consider applications in Radiation Oncology. Current lasers can generate proton beams with kinetic energies up to 67.5 MeV, but for therapy applications, the proton kinetic energy must reach 250 MeV. Since the maximum kinetic energy Emax of the proton scales with laser light intensity as Emax ∝ I0.5, next generation lasers may very well accelerate 250 MeV protons. As the kinetic energy of the protons is increased, the magnetic field strength of the solenoid will need to increase. The scaling of the magnetic field B with the kinetic energy of the protons follows B ∝ E1/2. Therefor, the field strength of the solenoid presented in this work will need to be increased by a factor of 2.4 in order to accommodate 250 MeV protons. This scaling factor seems reasonable, even with present technology. This work not only demonstrates control over beam divergence and energy spread, it also allows for us to now perform feasibility studies to further research what a laser-based proton therapy system

  15. Excimer Laser Pulse Compress With Pulse Feedback

    2008-01-01

    <正>To attain a shorter laser pulse, a compressing technique called pulse feedback was developed from the saturation gain switch applied to the amplification in a discharge pumping excimer laser cavity. It can

  16. Long Pulse EBW Start-up Experiments in MAST

    Shevchenko V.F.

    2015-01-01

    Full Text Available Start-up technique reported here relies on a double mode conversion (MC for electron Bernstein wave (EBW excitation. It consists of MC of the ordinary (O mode, entering the plasma from the low field side of the tokamak, into the extraordinary (X mode at a mirror-polarizer located at the high field side. The X mode propagates back to the plasma, passes through electron cyclotron resonance (ECR and experiences a subsequent X to EBW MC near the upper hybrid resonance (UHR. Finally the excited EBW mode is totally absorbed at the Doppler shifted ECR. The absorption of EBW remains high even in cold rarefied plasmas. Furthermore, EBW can generate significant plasma current giving the prospect of a fully solenoid-free plasma start-up. First experiments using this scheme were carried out on MAST [1]. Plasma currents up to 33 kA have been achieved using 28 GHz 100kW 90ms RF pulses. Recently experimental results were extended to longer RF pulses showing further increase of plasma currents generated by RF power alone. A record current of 73kA has been achieved with 450ms RF pulse of similar power. The current drive enhancement was mainly achieved due to RF pulse extension and further optimisation of the start-up scenario.

  17. Research on the Pulsed Magnetic Field Device for Sterilization of Fruit and Vegetable Equipment

    Liu Mingdan

    2013-04-01

    Full Text Available In view of the requests of the sterilization device of the fruit and vegetable that integrate cleaning and juicing together, and combined with the electromagnetic theory and the cold sterilization technology which is in common use in modern food industry, circuits are designed for the pulsed magnetic field sterilization device of the integrated machine .This circuits chose a linear solenoid in which r= 30mm, l= 200 mm. The experiment shows that the pulsed magnetic field produced by the device can achieve a better effect in killing bacillus coli, beer yeast and staphylococcus aurous, etc. Compared with the traditional sterilization device, the bactericidal effect of the pulsed magnetic field sterilization device is more obvious so that it will be the direction of the development of food equipments. [1]  

  18. A high-field pulsed magnet system for x-ray scattering studies in Voigt geometry

    Islam, Zahirul; Ruff, Jacob P C; Das, Ritesh K; Trakhtenberg, Emil; Nojiri, Hiroyuki; Narumi, Yasuo; Canfield, Paul C

    2011-01-01

    We present a new pulsed-magnet system that enables x-ray single-crystal diffraction in addition to powder and spectroscopic studies in Voigt geometry. The apparatus consists of a large-bore solenoid, cooled by liquid nitrogen. A second independent closed-cycle cryostat is used for cooling samples near liquid helium temperatures. Pulsed magnetic fields up to ~30 T with a minimum of ~6 ms in total duration are generated by discharging a 40 kJ capacitor bank into the magnet coil. The unique characteristic of this instrument is the preservation of maximum scattering angle (~23.6 deg.) through the magnet bore by virtue of a novel double-funnel insert. This instrument would facilitate x-ray diffraction and spectroscopic studies that are impractical, if not impossible, to perform using conventional split-pair magnets and offers a practical solution for preserving optical access in future higher-field pulsed magnets.

  19. High-performance pulsed magnets: Theory, design and construction

    Li, Liang

    This thesis is an in-depth study of the design and construction of coils for pulsed magnets energised by a capacitor bank, including mathematical modelling and testing of the coils. The magnetic field generated by solenoid magnets with homogeneous and non-homogenous current distribution is calculated with the elliptical integral method. Coupled partial differential equations for magnetic and thermal diffusion and the electric circuits are solved numerically to calculate the pulse shape and the heating in a pulsed magnet. The calculations are in good agreement with test results for a large range of different coils; this provides useful insights for optimised coil design. Stresses and strains in the mid-plane of the coil are analytically calculated by solving the system of equations describing the displacement in each layer of the coil. Non-linear stress-strain characteristics and the propagation of the plastic deformation are taken into account by sub- dividing each layer of the coil in the radial direction and changing the elastic-plastic matrix at each transition point. Conductors, insulating materials and techniques used for pulsed magnets are discussed in detail. More than 80 pulsed magnets with optimised combinations of conductors and reinforcements have been built and tested, with peak fields in the range 45-73 T and a bore size from 8 mm-35 mm. The pulse duration is of the order of 10 milliseconds. A dual stage pulsed magnet for use at a free electron laser has been developed. This has a rise time of 10 microseconds and enables magneto-optical experiments in a parameter range previously inaccessible to condensed matter physicists. The joint of superconducting cables can be modelled by means of distributed circuit elements that characterise current diffusion.

  20. Pulsed Optics

    Hirlimann, C.

    Optics is the field of physics which comprises knowledge on the interaction between light and matter. When the superposition principle can be applied to electromagnetic waves or when the properties of matter do not depend on the intensity of light, one speaks of linear optics. This situation occurs with regular light sources such as light bulbs, low-intensity light-emitting diodes and the sun. With such low-intensity sources the reaction of matter to light can be characterized by a set of parameters such as the index of refraction, the absorption and reflection coefficients and the orientation of the medium with respect to the polarization of the light. These parameters depend only on the nature of the medium. The situation changed dramatically after the development of lasers in the early sixties, which allowed the generation of light intensities larger than a kilowatt per square centimeter. Actual large-scale short-pulse lasers can generate peak powers in the petawatt regime. In that large-intensity regime the optical parameters of a material become functions of the intensity of the impinging light. In 1818 Fresnel wrote a letter to the French Academy of Sciences in which he noted that the proportionality between the vibration of the light and the subsequent vibration of matter was only true because no high intensities were available. The intensity dependence of the material response is what usually defines nonlinear optics.

  1. Quantification and visualization of cardiovascular 4D velocity mapping accelerated with parallel imaging or k-t BLAST: head to head comparison and validation at 1.5 T and 3 T

    Ståhlberg Freddy

    2011-10-01

    Full Text Available Abstract Background Three-dimensional time-resolved (4D phase-contrast (PC CMR can visualize and quantify cardiovascular flow but is hampered by long acquisition times. Acceleration with SENSE or k-t BLAST are two possibilities but results on validation are lacking, especially at 3 T. The aim of this study was therefore to validate quantitative in vivo cardiac 4D-acquisitions accelerated with parallel imaging and k-t BLAST at 1.5 T and 3 T with 2D-flow as the reference and to investigate if field strengths and type of acceleration have major effects on intracardiac flow visualization. Methods The local ethical committee approved the study. 13 healthy volunteers were scanned at both 1.5 T and 3 T in random order with 2D-flow of the aorta and main pulmonary artery and two 4D-flow sequences of the heart accelerated with SENSE and k-t BLAST respectively. 2D-image planes were reconstructed at the aortic and pulmonary outflow. Flow curves were calculated and peak flows and stroke volumes (SV compared to the results from 2D-flow acquisitions. Intra-cardiac flow was visualized using particle tracing and image quality based on the flow patterns of the particles was graded using a four-point scale. Results Good accuracy of SV quantification was found using 3 T 4D-SENSE (r2 = 0.86, -0.7 ± 7.6% and although a larger bias was found on 1.5 T (r2 = 0.71, -3.6 ± 14.8%, the difference was not significant (p = 0.46. Accuracy of 4D k-t BLAST for SV was lower (p 2 = 0.65, -15.6 ± 13.7% compared to 3 T (r2 = 0.64, -4.6 ± 10.0%. Peak flow was lower with 4D-SENSE at both 3 T and 1.5 T compared to 2D-flow (p Conclusions The present study showed that quantitative 4D flow accelerated with SENSE has good accuracy at 3 T and compares favourably to 1.5 T. 4D flow accelerated with k-t BLAST underestimate flow velocities and thereby yield too high bias for intra-cardiac quantitative in vivo use at the present time. For intra-cardiac 4D-flow visualization, however, 1.5 T and 3 T as well as SENSE or k-t BLAST can be used with similar quality.

  2. Development of Long-Lifetime Pulsed Gas Valves for Pulsed Electric Thrusters

    Burkhardt, Wendel M.; Crapuchettes, John M.; Addona, Brad M.; Polzin, Kurt A.

    2015-01-01

    even 10(exp 9) cycles is well above anything demonstrated, this lower value was selected as the design point for the present work. The valve seal must remain leak-tight throughout operation, and the body must maintain a low internal leakage at relatively high operating temperatures. The full set of design requirements used for this program are summarized in Table 1. In this work, we describe two pulsed gas valves that have been fabricated to have long lifetime and demonstrate the characteristics listed above. The first is a miniaturized, conventional electromagnet-based valve while the second is a piezoelectric-based valve design. The conventional valve, shown in Fig. 1, is opened by use of a solenoid electromagnetic actuator. When current is applied to the solenoid coil, magnetic forces pull the plunger away from the valve seat, allowing fluid to flow through the valve. Removal of electrical current permits the spring and fluid pressure to seat the plunger, halting the flow of fluid. The valve body is fabricated from 304L corrosion resistant steel (CRES) and while the parts that form the magnetic circuit are fabricated from 430 CRES. This material does not have optimum magnetic properties, but its corrosion resistance permits incorporation into a design without requiring an additional plating process. A viton O-ring compound (Parker V0884-75), selected for its mechanical strength at elevated temperatures, was used for the valve seat seal. The design was based solely on the use of analytical sizing calculations, as opposed to a more rigorous finite element analysis. While this valve is small and relatively lightweight, it does not represent a design that is optimized for mass and/or a given volume envelope. The piezoelectric valve is a "puller" valve design. Applying a voltage to the piezo crystal causes it to elongate and pull a pintle off the seat, opening the valve. The valve seal consists of the pintle with an external, spherically-formed tip fabricated from

  3. 电磁阀的失效模式及维修策略%Solenoid Valve Failure Mode and Maintenance Strategy

    蒋道福

    2012-01-01

    大亚湾和岭澳核电站使用了很多进口电磁阀.随着服役时间不断增加,大量电磁阀出现了漏气、漏油和生锈等故障现象;对这些故障现象进行分类,并结合相关资料分析了电磁阀的工作原理,总结出电磁阀的失效模式;参考法国电力公司(EDF)的维修方法,提出了大亚湾与岭澳核电站电磁阀的维修策略,对相关核电厂电磁阀的维修具有一定的参考价值.%Many solenoid valves were imported from France for Daya Bay and Ling'Ao nuclear power plants. Some phenomena of leaking air or oil and rustiness occurred in solenoid valves with the serve time increases. All malfunction phenomena were classified, operation principle of the solenoid valve was analyzed in combination with relevant information, and the failure mode was summarized. The maintenance strategy of the solenoid valve for Daya Bay and Ling'Ao nuclear power plants was put forward, with reference to the maintenance methods of EDF. It could be served as reference for solenoid valve maintenance in nuclear power plants of similar kind.

  4. Analysis of transverse RMS emittance growth of a beam induced by spherical and chromatic aberration in a solenoidal field

    Dash, Radhakanta, E-mail: radhakanta.physics@gmail.com [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Nayak, Biswaranjan [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Sharma, Archana; Mittal, Kailash C. [Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2016-01-21

    In a medium energy beam transport line transverse rms emittance growth associated with spherical aberration is analysed. An analytical expression is derived for beam optics in a solenoid field considering terms up to the third order in the radial displacement. Two important phenomena: effect of spherical aberrations in axial-symmetric focusing lens and influence of nonlinear space charge forces on beam emittance growth are discussed for different beam distributions. In the second part nonlinear effect associated with chromatic aberration that describes the growth of emittance and distortion of phase space area is discussed.

  5. Analysis of transverse RMS emittance growth of a beam induced by spherical and chromatic aberration in a solenoidal field

    Dash, Radhakanta; Nayak, Biswaranjan; Sharma, Archana; Mittal, Kailash C.

    2016-01-01

    In a medium energy beam transport line transverse rms emittance growth associated with spherical aberration is analysed. An analytical expression is derived for beam optics in a solenoid field considering terms up to the third order in the radial displacement. Two important phenomena: effect of spherical aberrations in axial-symmetric focusing lens and influence of nonlinear space charge forces on beam emittance growth are discussed for different beam distributions. In the second part nonlinear effect associated with chromatic aberration that describes the growth of emittance and distortion of phase space area is discussed.

  6. Averaged state model based design of nonlinear observer for the on/off solenoid valve pneumatic actuators

    Laib, Khaled; Megnous, Ahmed Rhéda; Pham, Minh Tu; Lin-Shi, Xuefang

    2016-01-01

    This report presents an averaged model and nonlinear observer for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The averaged model is elaborated which has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a sliding mode observer is designed using the piston's position and the pressure measurements in one of the chambers to estimate the piston velocity and the pressure in the other ...

  7. Generation and measurement of pulsed high magnetic field

    Jana, S

    2000-01-01

    Pulsed magnetic field has been generated by discharging a capacitor bank through a 5-layer air-core solenoid. The strength of the magnetic field at its peak has been measured using the voltage induced in various pick-up coils, and also from the Zeeman splitting of an ion having a known g value. Synchronizing a xenon flash at the peak of the magnetic field, this lab-made instrument has been made well suited to study the Zeeman effect, etc. at a temperature of 25 K. As an application of this setup, we have investigated the Zeeman splitting of the sup 4 I sub 9 sub / sub 2-> sup 4 G sub 5 sub / sub 2 transition of the Nd sup 3 sup + -doped CsCdCl sub 3 crystal at 7.8 T, and determined the splitting factors.

  8. A pulse-tube refrigerator using variable-resistance orifice

    Huang, B. J.; Sun, B. W.

    2003-01-01

    In the present study, we propose a new design of orifice pulse-tube refrigerator (VROPT) using a variable-resistance valve to replace the conventional orifice. The variable-resistance orifice (VRO) is basically a high-speed solenoidal valve similar to the fuel jet device widely used in automobile engines. By changing the frequency and periods of ON and OFF of the valve through an electronic device, we can change the flow resistance of the VRO. This thus provides a possibility for an OPT to be controlled on-line during operation. From the results obtained in the present study, we have shown that VROPT is able to achieve on-line control by regulating the duty cycle d or frequency fv of the VRO. We also show that VROPT will not loss its thermal performance as compared to conventional OPT.

  9. New Physics Search in Dijet Mass Spectrum with Compact Muon Solenoid

    Jeong, Chiyoung [Texas Tech Univ., Lubbock, TX (United States)

    2011-01-01

    Many extensions of the SM predict the existence of new massive objects that couple to quarks and gluons and result in resonances in the dijet mass spectrum. In this thesis we present a search for narrow resonances in the dijet mass spectrum using data corresponding to an integrated luminosity of 1 fb$^{-1}$ collected by the CMS experiment at the LHC, at a proton-proton collision energy of $\\sqrt{s}=7$ $TeV$. %This dijet analysis is searching for new particles in the dijet mass spectrum decaying to dijets. These new particles are predicted by new physics beyond Standard Model. This thesis presents a dijet analysis performed at the Compact Muon Solenoid (CMS) in pp collisions at $\\sqrt{s}=7$ $TeV$ for an integrated luminosities of 1.0 fb$^{-1}$. The dijet mass distribution of two leading jets is measured and compared to QCD predictions, simulated by PYTHIA with the CMS detector simulation. We select events which have two leading jets with $\\mid \\Delta\\eta \\mid < 1.3$ and $\\mid \\eta \\mid < 2.5$. We fit the dijet mass spectrum with QCD parameters. Since no evidence of new physics was found, we set upper limits at 95\\% CL on the resonance cross section and compare to the theoretical prediction for several models of new particles: string resonances, axigluons, colorons, excited quarks, $E_{6}$ diquarks, Randall-Sundrum gravitons, W' and Z'. We exclude at 95\\% CL string resonances in the mass range $1.0 < M(S) < 4.00$ TeV, excited quarks in the mass range $1.0

  10. Part-body hyperthermia with a radiofrequency multiantenna applicator under online control in 1,5 T MR-tomograph; Teilkoerperhyperthermie mit einem Radiofrequenz-Multiantennen-Applikator unter on-line Kontrolle in einem 1,5 T MR-Tomographen

    Wust, P.; Gellermann, J.; Faehling, H.; Wlodarczyk, W.; Felix, R. [Charite, Klinik fuer Strahlenheilkunde, Berlin (Germany); Seebass, M. [Konrad-Zuse-Zentrum fuer Informationstechnologie, Berlin (Germany); Turner, P. [BSD Medical Corp., Salt Lake City, UT (United States); Nadobny, J. [Charite, Klinik fuer Strahlenheilkunde, Berlin (Germany); Konrad-Zuse-Zentrum fuer Informationstechnologie, Berlin (Germany); Rau, B. [Charite, Medizinische Klinik m.S. Haematologie und Onkologie, Berlin (Germany); Hildebrandt, B.; Schlag, P.M. [Charite, Klinik fuer Chirurgie und Chirurgische Onkologie, Berlin (Germany); Oppelt, A. [Siemens Medical Solutions, Interventional MR, Erlangen (Germany)

    2004-03-01

    Objective of this study is the integration of a multiantenna applicator for part-body hyperthermia (BSD 2000/3D) in a 1.5 T MR-tomograph (Siemens Magnetom Symphony) in order to perform noninvasive MR monitoring in real time to increase safety and effectiveness of heat treatments. The positioning unit is mechanically coupled to the MR gantry from the back side and the body coil is utilised for imaging. For that purpose, the hyperthermia antenna system (100 MHz, 1.500 W) and the MR receiver(63.9 MHs) have to be decoupled in terms of high frequency (filter) and electromagnetically (emc). The processing of MR data sets is performed in a hyperthermia planning system. A simultaneous operation of radiofrequency hyperthermia and MR system is possible at clinically relevant power levels. MR imaging is used for tumor diagnostics (standard spin echo sequences), for hyperthermia planning (T1-weighted gradient echo sequences in equal- and opposed-phase techniques), and for temperature measurements according to the proton resonance frequency method (PRF method, phase evaluation registration using a gradient echo sequence with long echo time). In 33 patients with advanced pelvic and abdominal tumors we performed 150 heat sessions under MR monitoring. For 70% of these patients a visualisation of temperature sensitive data during treatment was possible. The evaluated difference images represent a superposition of real temperature increase and a (temperature-induced) perfusion elevation. The hybrid approach renders development of part body hyperthermia possible as an MR-controlled intervention in radiology. (orig.) [German] Ziel ist die Integration eines Multiantennen-Applikators fuer die Teilkoerperhyperthermie (BSD-2000/3D) in einen 1,5 T MR-Tomographen (Siemens Magnetom Symphony), um ein nicht-invasives MR-Monitoring in Echtzeit zu ermoeglichen und damit die Hyperthermie sicherer und effektiver durchfuehren zu koennen. Die Hyperthermie-Lagerungseinheit wird von der Rueckseite der MR-Gantry mechanisch angekoppelt und die Koerperschule zum Monitoring eingesetzt. Dazu mussten Hyperthermie-Antennensystem (100 MHz, 1550 W) und MR-Empfaenger (63,9 MHz) hochfrequenzmaessig (Filter) und elektromagnetisch entkoppelt werden. Die Weiterverarbeitung der MR-Datensaetze erfolgt in einem eigens entwickelten Hyperthermieplanungssystem. Ein Simultanbetrieb von Radiofrequenz-Hyperthermie und MR-System ist bei klinisch relevanten Leistungen moeglich. MR-Datensaetze werden zur diagnostischen Tumordarstellung (Spin-Echo-Standardsequenzen), zur Planung der Hyperthermie (T{sub 1}-gewichtete Gradienten-Echo-Sequenzen in Gegen- und Gleichphasentechnik) und zur Temperaturdarstellung nach der Protonen-Resonanzfrequenz-Methode (PRF-Methode, Phasenauswertung einer Gradienten-Echo-Sequenz mit langer Echozeit) eingesetzt. Bei 33 Patienten mit fortgeschrittenen pelvinen und abdominellen Tumoren wurden ueber 150 Hyperthermiebehandlungen unter MR-Monitoring durchgefuehrt. Bei 70% der Patienten gelang eine Visualisierung temperatursensitiver Daten waehrend der Therapiezeit. Die ausgewerteten Differenzbilder stellen eine Ueberlagerung der tatsaechlichen Temperaturerhoehung und einer (temperaturinduzierten) Perfusionserhoehung dar. Dieser Hybridansatz ermoeglicht es, die Teilkoerperhyperthermie als MR-gesteuerte Intervention fuer die Radiologie zu entwickeln. (orig.)

  11. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears*

    Chagas-Neto, Francisco Abaeté; Nogueira-Barbosa, Marcello Henrique; Lorenzato, Mário Müller; Salim, Rodrigo; Kfuri-Junior, Maurício; Crema, Michel Daoud

    2016-01-01

    Objective To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition. PMID:27141127

  12. Diagnostic performance of 3D TSE MRI versus 2D TSE MRI of the knee at 1.5 T, with prompt arthroscopic correlation, in the detection of meniscal and cruciate ligament tears

    Francisco Abaeté Chagas-Neto

    2016-04-01

    Full Text Available Abstract Objective: To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE magnetic resonance imaging (MRI technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods: Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results: For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively and specificity (80% and 85%, respectively. For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively and specificity (68% and 71%, respectively. In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively and specificity (82% and 92%, respectively. There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion: The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition.

  13. Evaluation of Porcine Pancreatic Islets Transplanted in the Kidney Capsules of Diabetic Mice Using a Clinically Approved Superparamagnetic Iron Oxide (SPIO) and a 1.5T MR Scanner

    Kim, Hoe Suk; Kim, Hyoung Su; Park, Kyong Soo; Moon, Woo Kyung [Seoul National University Hospital, Seoul (Korea, Republic of)

    2010-12-15

    To evaluate transplanted porcine pancreatic islets in the kidney capsules of diabetic mice using a clinically approved superparamagnetic iron oxide (SPIO) and a 1.5T MR scanner. Various numbers of porcine pancreatic islets labeled with Resovist, a carboxydextran-coated SPIO, were transplanted into the kidney capsules of normal mice and imaged with a 3D FIESTA sequence using a 1.5T clinical MR scanner. Labeled (n = 3) and unlabeled (n = 2) islets were transplanted into the kidney capsules of streptozotocin-induced diabetic mice. Blood glucose levels and MR signal intensities were monitored for 30 days post-transplantation. There were no significant differences in viability or insulin secretion between labeled and unlabeled islets. A strong correlation ({gamma} {sup 2} > 0.94) was evident between the number of transplanted islets and T{sub 2} relaxation times quantified by MRI. Transplantation with labeled or unlabeled islets helped restore normal sustained glucose levels in diabetic mice, and nephrectomies induced the recurrence of diabetes. The MR signal intensity of labeled pancreatic islets decreased by 80% over 30 days. The transplantation of SPIO-labeled porcine islets into the kidney capsule of diabetic mice allows to restore normal glucose levels, and these islets can be visualized and quantified using a 1.5T clinical MR scanner

  14. Programmable pulse generator

    Xue Zhi Hua; Duan Xiao Hui

    2002-01-01

    The author introduces the design of programmable pulse generator that is based on a micro-controller and controlled by RS232 interface of personal computer. The whole system has good stability. The pulse generator can produce TTL pulse and analog pulse. The pulse frequency can be selected by EPLD. The voltage amplitude and pulse width of analog pulse can be adjusted by analog switches and digitally-controlled potentiometers. The software development tools of computer is National Instruments LabView5.1. The front panel of this virtual instrumentation is intuitive and easy-to-use. Parameters can be selected and changed conveniently by knob and slide

  15. Measurements of the temporal onset of mega-Gauss magnetic fields in a laser-driven solenoid

    Goyon, Clement; Polllock, B. B.; Turnbull, D. T.; Hazi, A.; Ross, J. S.; Mariscal, D. A.; Patankar, S.; Williams, G. J.; Farmer, W. A.; Moody, J. D.; Fujioka, S.; Law, K. F. F.

    2016-10-01

    We report on experimental results obtained at Omega EP showing a nearly linear increase of the B-field up to about 2 mega-Gauss in 0.75 ns in a 1 mm3 region. The field is generated using 1 TW of 351 nm laser power ( 8*1015 W/cm2) incident on a laser-driven solenoid target. The coil target converts about 1% of the laser energy into the B-field measured both inside and outside the coil using proton deflectometry with a grid and Faraday rotation of probe beam through SiO2 glass. Proton data indicates a current rise up to hundreds of kA with a spatial distribution in the Au solenoid conductor evolving in time. These results give insight into the generating mechanism of the current between the plates and the time behavior of the field. These experiments are motivated by recent efforts to understand and utilize High Energy Density (HED) plasmas in the presence of external magnetic fields in areas of research from Astrophysics to Inertial Confinement Fusion. We will describe the experimental results and scale them to a NIF hohlraum size. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  16. Turbulence in the Inter-galactic Medium: Solenoidal and Dilatational Motions, and the Impact of Numerical Viscosity

    Zhu, Weishan; Xia, Yinhua; Shu, Chi-Wang; Gu, Qiu-Sheng; Fang, Li-Zhi

    2013-01-01

    We use a suite of cosmological hydrodynamic simulations, run by two fixed grid codes, to investigate the properties of solenoidal and dilatational motions of the intergalactic medium (IGM), and the impact of numerical viscosity on turbulence in a LCDM universe. The codes differ only in the spatial difference discretization. We find that (1) The vortical motion grows rapidly since $z=2$, and reaches $\\sim 10 km/s -90 km/s$ at $z=0$. Meanwhile, the small-scale compressive ratio $r_{CS}$ drops from 0.84 to 0.47, indicating comparable vortical and compressive motions at present. (2) Power spectra of the solenoidal velocity possess two regimes, $\\propto k^{-0.89}$ and $\\propto k^{-2.02}$, while the total and dilatational velocity follow the scaling $k^{-1.88}$ and $k^{-2.20}$ respectively in the turbulent range. The IGM turbulence may contain two distinct phases, the supersonic and post-supersonic phases. (3) The non-thermal pressure support, measured by the vortical kinetic energy, is comparable with the thermal ...

  17. HIE-Isolde: Commissioning and first results of the Mathilde system monitoring the positions of cavities and solenoids inside cryomodules

    Kautzmann, Guillaume; Klumb, Francis; CERN. Geneva. ATS Department

    2016-01-01

    The new superconducting HIE-ISOLDE Linac replaced most of pre-existing REX ISOLDE facility at CERN. This upgrade involves the design, construction, installation and commissioning of 4 high-β cryomodules. Each high-β cryomodule houses five superconducting cavities and one superconducting solenoid. Beam-physics simulations show that the optimum linac working conditions are obtained when the main axes of the active components, located inside the cryostats, are aligned and permanently monitored on the REX Nominal Beam Line (NBL) within a precision of 0.3 mm for the cavities and 0.15 mm for the solenoids at one sigma level along directions perpendicular to the beam axis. The Monitoring and Alignment Tracking for HIE-ISOLDE (MATHILDE) system has been developed to fulfil the alignment and monitoring needs for components exposed to non-standard environmental conditions such as high vacuum or cryogenic temperatures. MATHILDE is based on opto-electronic sensors (HBCAM) observing, through high quality viewports, spher...

  18. A conduction-cooled, 680-mm-long warm bore, 3-T Nb3Sn solenoid for a Cerenkov free electron laser

    Wessel, W. A. J.; Ouden, den, J.; Krooshoop, H. J. G.; Kate, ten, H.H.J.; Wieland, J.; Slot, van der, J.

    1999-01-01

    A compact, cryocooler cooled Nb3Sn superconducting magnet system for a Cerenkov free electron laser has been designed, fabricated and tested. The magnet is positioned directly behind the electron gun of the laser system. The solenoidal field compresses and guides a tube-shaped 100 A, 500 kV electron beam. A two-stage GM cryocooler, equipped with a first generation ErNi5 regenerator, cools the epoxy impregnated solenoid down to the operating temperature of about 7.5 K. This leaves a conservati...

  19. Development of cryocooler-cooled solenoid magnet fabricated with Bi-2212 ROSAT wire; Bi-2212 ROSAT wire wo mochiita reitoki dendo reikyaku sorenoido magunetto no kaihatsu

    Azuma, K.; Morita, H.; Hara, N.; Okada, M. [Hitachi Ltd., Tokyo (Japan); Sato, J. [Hitachi Cable Ltd., Tokyo (Japan); Kitaguchi, H.; Kumakura, H.; Togano, K. [National Research Inst. for Metals, Tokyo (Japan)

    1999-11-10

    The asymmetry for external magnetic field is a small wire rod, while Bi-2212 ROSATwire keeps the transport current characteristics which tape wire rod is excellent. And, the wind ability becomes good by choosing the round cross section, and it is a wire rod, which is suitable for solenoidal coil. At present, refrigerating machine conduction cooling type solenoid magnet, which can generate central magnetic field 8T using this wire rod is developed. This time, the internal layer coil was manufactured, and the excitation test was carried out by the cooling system for the test. (NEDO)

  20. Development of cryocooler-cooled solenoid magnet fabricated with Bi-2212 ROSAT wire (2); Bi-2212 ROSAT wire wo mochiita reitoki dendo reikyaku sorenoido magunetto no kaihatsu (2)

    Morita, H.; Tanaka, K.; Hara, N. [Hitachi Ltd., Tokyo (JP)] [and others

    2000-05-29

    The asymmetry for external magnetic field is a small wire rod, while Bi-2212ROSATwire keeps the transport current characteristics which tape wire rod is excellent. And, the windability becomes good by choosing the round cross section, and it is goodwill wire rod in the solenoidal coil. At present, it develops refrigerating machine conduction cooling type solenoid magnet system using this wire rod. This time, it produced refrigerating machine conduction cooling system, which could install new internal layer coil using the wire rod improved and magnet of 3 layers. (NEDO)

  1. Conceptual design for the superconducting magnet system of a pulsed DEMO reactor

    Duchateau, J.-L., E-mail: jean-luc.duchateau@cea.fr [CEA/IRFM, 13108 St. Paul lez Durance Cedex (France); Hertout, P.; Saoutic, B.; Magaud, P.; Artaud, J.-F.; Giruzzi, G.; Bucalossi, J.; Johner, J.; Sardain, P.; Imbeaux, F.; Ané, J.-M.; Li-Puma, A. [CEA/IRFM, 13108 St. Paul lez Durance Cedex (France)

    2013-10-15

    Highlights: ► A 1D design approach of a pulsed DEMO reactor is presented. ► The main CS and TF conductor design criteria are presented. ► A typical major radius for a 2 GW DEMO is 9 m. ► A typical plasma magnetic field is 4.9 T. ► The pulse duration is 1.85 h for an aspect ratio of 3. -- Abstract: A methodology has been developed to consistently investigate, taking into account main reactor components, possible magnet solutions for a pulsed fusion reactor aiming at a large solenoid flux swing duration within the 2–3 h range. In a conceptual approach, investigations are carried out in the equatorial plane, taking into account the radial extension of the blanket-shielding zone, of the toroidal field magnet system inner leg and of the central solenoid for estimation of the pulsed swing. Design criteria are presented for the radial extension of the superconducting magnets, which is mostly driven by the structures (casings and conductor jacket). Typical available cable current densities are presented as a function of the magnetic field and of the temperature margin. The magnet design criteria have been integrated into SYCOMORE, a code for reactor modeling presently in development at CEA/IRFM in Cadarache, using the tools of the EFDA Integrated Tokamak Modeling task force. Possible solutions are investigated for a 2 GW fusion power reactor with different aspect ratios. The final adjustment of the DEMO pulsed reactor parameters will have to be consistently done, considering all reactor components, when the final goals of the machine will be completely clarified.

  2. Experimental investigation of jet pulse control on flexible vibrating structures

    Karaiskos, Grigorios; Papanicolaou, Panos; Zacharopoulos, Dimitrios

    2016-08-01

    The feasibility of applying on-line fluid jet pulses to actively control the vibrations of flexible structures subjected to harmonic and earthquake-like base excitations provided by a shake table is explored. The operating principles and capabilities of the control system applied have been investigated in a simplified small-scale laboratory model that is a mass attached at the top free end of a vertical flexible slender beam with rectangular cross-section, the other end of which is mounted on an electrodynamic shaker. A pair of opposite jets placed on the mass at the top of the cantilever beam applied the appropriate forces by ejecting pressurized air pulses controlled by on/off solenoid electro-valves via in house developed control software, in order to control the vibration caused by harmonic, periodic and random excitations at pre-selected frequency content provided by the shaker. The dynamics of the structure was monitored by accelerometers and the jet impulses by pressure sensors. The experimental results have demonstrated the effectiveness and reliability of Jet Pulse Control Systems (JPCS). It was verified that the measured root mean square (RMS) vibration levels of the controlled structure from harmonic and earthquake base excitations, could be reduced by approximately 50% and 33% respectively.

  3. Physics of Neutralization of Intense Charged Particle Beam Pulses by a Background Plasma

    Kaganovich, I.D.; Davidson, R.C.; Dorf, M.A.; Startsev, E.A.; Sefkow, A.B; Friedman, A.F.; Lee, E.P.

    2009-09-03

    Neutralization and focusing of intense charged particle beam pulses by a background plasma forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self-magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating

  4. Physics of Neutralization of Intense High-Energy Ion Beam Pulses by Electrons

    Kaganovich, I. D.; Davidson, R. C.; Dorf, M. A.; Startsev, E. A.; Sefkow, A. B.; Lee, E. P.; Friedman, A.

    2010-04-28

    Neutralization and focusing of intense charged particle beam pulses by electrons forms the basis for a wide range of applications to high energy accelerators and colliders, heavy ion fusion, and astrophysics. For example, for ballistic propagation of intense ion beam pulses, background plasma can be used to effectively neutralize the beam charge and current, so that the self-electric and self- magnetic fields do not affect the ballistic propagation of the beam. From the practical perspective of designing advanced plasma sources for beam neutralization, a robust theory should be able to predict the self-electric and self-magnetic fields during beam propagation through the background plasma. The major scaling relations for the self-electric and self-magnetic fields of intense ion charge bunches propagating through background plasma have been determined taking into account the effects of transients during beam entry into the plasma, the excitation of collective plasma waves, the effects of gas ionization, finite electron temperature, and applied solenoidal and dipole magnetic fields. Accounting for plasma production by gas ionization yields a larger self-magnetic field of the ion beam compared to the case without ionization, and a wake of current density and self-magnetic field perturbations is generated behind the beam pulse. A solenoidal magnetic field can be applied for controlling the beam propagation. Making use of theoretical models and advanced numerical simulations, it is shown that even a small applied magnetic field of about 100G can strongly affect the beam neutralization. It has also been demonstrated that in the presence of an applied magnetic field the ion beam pulse can excite large-amplitude whistler waves, thereby producing a complex structure of self-electric and self-magnetic fields. The presence of an applied solenoidal magnetic field may also cause a strong enhancement of the radial self-electric field of the beam pulse propagating through the

  5. Radial pulse (image)

    ... heart. The arteries are the vessels with the "pulse", a rhythmic pushing of the blood in the ... a refilling of the heart chamber. To determine heart rate, one feels the beats at a pulse point ...

  6. Wrist pulse (image)

    To measure the pulse at the wrist, place the index and middle finger over the underside of the opposite wrist, below the base ... firmly with flat fingers until you feel the pulse in the radial artery.

  7. Molecular imaging probes spy on the body's inner workings: miniaturized microscopes, microbubbles, 7- and 15-T scanners, diffusion-tensor MRI, and other molecular-imaging technologies are pushing molecular imaging into the future.

    Mertz, Leslie

    2013-01-01

    Molecular imaging is one of the hot-button areas within medical imaging. This technology employs imaging techniques in concert with molecular probes, or biomarkers, that together noninvasively spy on cellular function and molecular processes. In some cases, this technology may be able to detect the very earliest stages of diseases and eliminate them on the spot. This paper discusses how miniaturized microscopes, microbubbles, 7T and 15T scanners, diffusion-tensor MRI and other molecular imaging technologies are pushing molecular imaging into the future.

  8. Pulse-Width Jitter Measurement for Laser Diode Pulses

    TANG Jun-Hua; WANG Yun-Cai

    2006-01-01

    @@ Theoretical analysis and experimental measurement of pulse-width jitter of diode laser pulses are presented. The expression of pulse power spectra with all amplitude jitter, timing jitter and pulse-width jitter is deduced.

  9. A conduction-cooled, 680-mm-long warm bore, 3-T Nb3Sn solenoid for a Cerenkov free electron laser

    Wessel, W.A.J.; Ouden, den A.; Krooshoop, H.J.G.; Kate, ten H.H.J.; Wieland, J.; Slot, van der P.J.M.

    1999-01-01

    A compact, cryocooler cooled Nb3Sn superconducting magnet system for a Cerenkov free electron laser has been designed, fabricated and tested. The magnet is positioned directly behind the electron gun of the laser system. The solenoidal field compresses and guides a tube-shaped 100 A, 500 kV electron

  10. Manipulation of magnetic carriers for drug delivery using pulsed-current high T {sub c} superconductors

    Cha, Yung [Energy Technology Division and Material Science Division, Building 335, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)]. E-mail: yscha@anl.gov; Chen, Lihua [Energy Technology Division and Material Science Division, Building 335, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States); Askew, Thomas [Energy Technology Division and Material Science Division, Building 335, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Physics Department, Kalamazoo College, Kalamazoo, MI 49006 (United States); Veal, Boyd [Energy Technology Division and Material Science Division, Building 335, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hull, John [Energy Technology Division and Material Science Division, Building 335, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2007-04-15

    An innovative method of manipulating magnetic carriers is proposed, and its feasibility for drug delivery and therapy is demonstrated experimentally. The proposed method employs pulsed-field solenoid coils with high-critical- temperature (T {sub c}) superconductor inserts. Pulsed current is used to magnetize and de-magnetize the superconductor insert. The proposed method was demonstrated to be able to (1) move magnetic particles, ranging in size from a few millimeters to 10 {mu}m, with strong enough forces over a substantial distance, (2) hold the particles at a designated position as long as needed, and (3) reverse the processes and retrieve the particles. We further demonstrated that magnetic particles can be manipulated in a stationary environment, in water flow, and in simulated blood (water/glycerol mixture) flow.

  11. Manipulation of magnetic carriers for drug delivery using pulsed-current high Tc superconductors

    Cha, Yung; Chen, Lihua; Askew, Thomas; Veal, Boyd; Hull, John

    2007-04-01

    An innovative method of manipulating magnetic carriers is proposed, and its feasibility for drug delivery and therapy is demonstrated experimentally. The proposed method employs pulsed-field solenoid coils with high-critical- temperature ( Tc) superconductor inserts. Pulsed current is used to magnetize and de-magnetize the superconductor insert. The proposed method was demonstrated to be able to (1) move magnetic particles, ranging in size from a few millimeters to 10 μm, with strong enough forces over a substantial distance, (2) hold the particles at a designated position as long as needed, and (3) reverse the processes and retrieve the particles. We further demonstrated that magnetic particles can be manipulated in a stationary environment, in water flow, and in simulated blood (water/glycerol mixture) flow.

  12. Commissioning and Testing the 1970's Era LASS Solenoid Magnet in JLab's Hall D

    Ballard, Joshua T. [Jefferson Lab, Newport News, VA; Biallas, George H. [Jefferson Lab, Newport News, VA; Brown, G.; Butler, David E. [Jefferson Lab, Newport News, VA; Carstens, Thomas J. [Jefferson Lab, Newport News, VA; Chudakov, Eugene A. [Jefferson Lab, Newport News, VA; Creel, Jonathan D. [Jefferson Lab, Newport News, VA; Egiyan, Hovanes [Jefferson Lab, Newport News, VA; Martin, F.; Qiang, Yi [Jefferson Lab, Newport News, VA; Smith, Elton S. [Jefferson Lab, Newport News, VA; Stevens, Mark A. [Jefferson Lab, Newport News, VA; Spiegel, Scot L. [Jefferson Lab, Newport News, VA; Whitlatch, Timothy E. [Jefferson Lab, Newport News, VA; Wolin, Elliott J. [Carnegie Mellon University , Pittsburgh, PA; Ghoshal, Probir K. [Jefferson Lab, Newport News, VA

    2015-06-01

    JLab refurbished and reconfigured the LASS1, 1.85m bore Solenoid and installed it as the principal analysis magnet for nuclear physics in the newly constructed, Hall D at Jefferson Lab. The magnet contains four superconducting coils within an iron yoke. The magnet was built in the early1970's at Stanford Linear Accelerator Center and used a second time at Los Alamos National Laboratory. The coils were extensively refurbished and individually tested by JLab. A new Cryogenic Distribution Box provides cryogens and their control valving, current distribution bus, and instrumentation pass-through. A repurposed CTI 2800 refrigerator system and new transfer line complete the system. We describe the re-configuration, the process and problems of re-commissioning the magnet and the results of testing the completed magnet.

  13. Re-integration and Consolidation of the Detector Control System for the Compact Muon Solenoid Electromagnetic Calorimeter

    Holme, Oliver; Dissertori, Günther; Djambazov, Lubomir; Lustermann, Werner; Zelepoukine, Serguei

    2013-01-01

    The current shutdown of the Large Hadron Collider (LHC), following three successful years of physics data-taking, provides an opportunity for major upgrades to be performed on the Detector Control System (DCS) of the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment. The upgrades involve changes to both hardware and software, with particular emphasis on taking advantage of more powerful servers and updating third-party software to the latest supported versions. The considerable increase in available processing power enables a reduction from fifteen to three or four servers. To host the control system on fewer machines and to ensure that previously independent software components could run side-by-side without incompatibilities, significant changes in the software and databases were required. Additional work was undertaken to modernise and concentrate I/O interfaces. The challenges to prepare and validate the hardware and software upgrades are described along with details of the ...

  14. Study of some optical glues for the Compact Muon Solenoid at the Large Hadron Collider of CERN

    Montecchi, Marco

    2001-01-01

    Two Avalanche Photodiodes will measure the light produced in each of the 61,200 PbWO4 crystals composing the barrel part of the electromagnetic calorimeter of the Compact Muon Solenoid (CMS) at the Large Hadron Collider of CERN. To improve the collection of the photons, these detectors will be glued to the crystal. To be used in CMS, the optical glue must fulfil several requirements. The paper describes those requirements and reports the results of the investigation of several commercial optical glues. In particular, refractive index, absorption length, radiation hardness and forecast ageing after 15 years are reported. The most promising glue for CMS was more deeply investigated, in particular its chemical composition, chemical compatibility with the other parts of the calorimeter and curing time in realistic conditions.

  15. Pulse Pressure in Clinical Practice

    Jiri Parenica

    2012-02-01

    Full Text Available The review presents basic information about the pulse pressure. The variables related to pulse pressure are briefly explained - arterial stiffness, arterial compliance, pulse wave velocity, pulse pressure amplification and augmentation index. We present some recent trials and observational studies that show the importance of pulse pressure in clinical practice. Briefly the possibilities of influencing the pulse pressure are discussed.

  16. Characterisation of practical high temperature superconductors in pulsed magnetic fields and development of associated technology

    Saleh, P M

    2000-01-01

    including a innovative design of a 100ms pulsed magnet solenoid. Critical current measurements on state of the art practical high temperature superconductors are presented. Bi sub 2 Sr sub 2 CaCu sub 2 O silver-alloy matrix powder-in-tube and silver-alloy substrate dip-coated tapes, formed into various geometries, have been tested in pulsed magnetic fields of various pulse lengths. These measurements have been compared to tests performed in continuous magnetic fields. A distinct discrepancy between pulsed and continuous measurements has been observed in these silver-alloy, high temperature superconductor composites. The critical current measured in pulsed fields is depressed compared to those measured in continuous fields. Evidence is provided to strongly suggest that eddy current heating in the silver-alloy substrate/sheath of the conductor is responsible for this discrepancy. A model is presented to predict the temperature rise due to eddy current heating. This model shows good agreement with observations. ...

  17. Cryogenic pellet production developments for long-pulse plasma operation

    Meitner, S. J.; Baylor, L. R.; Combs, S. K.; Fehling, D. T.; McGill, J. M.; Duckworth, R. C.; McGinnis, W. D.; Rasmussen, D. A. [Oak Ridge National Laboratory, 1Bethel Valley Rd Oak Ridge, TN 37831 (United States)

    2014-01-29

    Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at a rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.

  18. Fuzzy logic structure analysis of trabecular bone of the calcaneus to estimate proximal femur fracture load and discriminate subjects with and without vertebral fractures using high-resolution magnetic resonance imaging at 1.5 T and 3 T.

    Patel, Priyesh V; Eckstein, Felix; Carballido-Gamio, Julio; Phan, Catherine; Matsuura, Maiko; Lochmüller, Eva-Maria; Majumdar, Sharmila; Link, Thomas M

    2007-10-01

    Newly developed fuzzy logic-derived structural parameters were used to characterize trabecular bone architecture in high-resolution magnetic resonance imaging (HR-MRI) of human cadaver calcaneus specimens. These parameters were compared to standard histomorphological structural measures and analyzed concerning performance in discriminating vertebral fracture status and estimating proximal femur fracture load. Sets of 60 sagittal 1.5 T and 3.0 T HR-MRI images of the calcaneus were obtained in 39 cadavers using a fast gradient recalled echo sequence. Structural parameters equivalent to bone histomorphometry and fuzzy logic-derived parameters were calculated using two chosen regions of interest. Calcaneal, spine, and hip bone mineral density (BMD) measurements were also obtained. Fracture status of the thoracic and lumbar spine was assessed on lateral radiographs. Finally, mechanical strength testing of the proximal femur was performed. Diagnostic performance in discriminating vertebral fracture status and estimating femoral fracture load was calculated using regression analyses, two-tailed t-tests of significance, and receiver operating characteristic (ROC) analyses. Significant correlations were obtained at both field strengths between all structural and fuzzy logic parameters (r up to 0.92). Correlations between histomorphological or fuzzy logic parameters and calcaneal BMD were mostly significant (r up to 0.78). ROC analyses demonstrated that standard structural parameters were able to differentiate persons with and without vertebral fractures (area under the curve [A(Z)] up to 0.73). However, none of the parameters obtained in the 1.5-T images and none of the fuzzy logic parameters discriminated persons with and without vertebral fractures. Significant correlations were found between fuzzy or structural parameters and femoral fracture load. Using multiple regression analysis, none of the structural or fuzzy parameters were found to add discriminative value to BMD alone. In summary significant correlations were obtained at both field strengths between all structural and fuzzy logic parameters. However, fuzzy logic-based calcaneal parameters were not well suited for vertebral fracture discrimination. Although significant correlations were found between fuzzy or structural parameters and femoral fracture load, multiple regression analysis showed limited improvement for estimating femoral failure load in addition to femoral BMD alone. Local femoral measurements are still needed to estimate femoral bone strength. Overall, parameters obtained at 3.0 T performed better than those at 1.5 T.

  19. PulseSoar

    Carter, P.; Peglow, S.

    1992-07-21

    This paper is an introduction to the PulseSoar concept. PulseSoar is a hypervelocity airplane that uses existing airport facilities and current technologies to fly at the very edge of space. It will be shown that PulseSoar can fly between any two points on the globe in less than two hours with fuel efficiency exceeding current state of the art commercial airliners. In addition, it will be shown that PulseSoar avoids environmental issues concerning the ozone layer and sonic booms because of its unique flight profile. All of this can be achieved with current technology. PulseSoar does not require the development of enabling technology. It is a concept which can be demonstrated today. The importance of this idea goes beyond the technical significance`s of PulseSoar in terms of feasibility and performance. PulseSoar could provide a crucial economic advantage to America`s largest export market: commercial aircraft. PulseSoar is a breakthrough concept for addressing the emerging markets of long range and high speed aircraft. Application of PulseSoar to commercial transport could provide the US Aerospace industry a substantial lead in offering high speed/long range aircraft to the world`s airlines. The rapid emergence of a US developed high speed aircraft could also be important to our competitiveness in the Pacific Rim and South American economies. A quick and inexpensive demonstration vehicle is proposed to bang the concept to reality within two years. This discussion will address all the major technical subjects encompassed by PulseSoar and identifies several near-term, and low risk, applications which may be further explored with the initial demonstration vehicle. What is PulseSoar? PulseSoar could enable high speed, high altitude and long range flight without many of the difficulties encountered by traditional hypersonic vehicles.

  20. Ultrashort Laser Pulse Phenomena

    Diels, Jean-Claude

    2006-01-01

    Ultrashort Laser Pulse Phenomena, 2e serves as an introduction to the phenomena of ultra short laser pulses and describes how this technology can be used to examine problems in areas such as electromagnetism, optics, and quantum mechanics. Ultrashort Laser Pulse Phenomena combines theoretical backgrounds and experimental techniques and will serve as a manual on designing and constructing femtosecond (""faster than electronics"") systems or experiments from scratch. Beyond the simple optical system, the various sources of ultrashort pulses are presented, again with emphasis on the basic

  1. Analysis of off-axis solenoid fields using the magnetic scalar potential: An application to a Zeeman-slower for cold atoms

    Muniz, Sérgio R.; Bagnato, Vanderlei S.; Bhattacharya, M.

    2015-06-01

    In a region free of currents, magnetostatics can be described by the Laplace equation of a scalar magnetic potential, and one can apply the same methods commonly used in electrostatics. Here, we show how to calculate the general vector field inside a real (finite) solenoid, using only the magnitude of the field along the symmetry axis. Our method does not require integration or knowledge of the current distribution and is presented through practical examples, including a nonuniform finite solenoid used to produce cold atomic beams via laser cooling. These examples allow educators to discuss the nontrivial calculation of fields off-axis using concepts familiar to most students, while offering the opportunity to introduce themes of current modern research.

  2. Simple analysis of off-axis solenoid fields using the scalar magnetostatic potential: application to a Zeeman-slower for cold atoms

    Muniz, Sérgio R; Bagnato, Vanderlei S

    2010-01-01

    In a region free of currents, magnetostatics can be described by the Laplace equation of a scalar magnetic potential, and one can apply the same methods commonly used in electrostatics. Here we show how to calculate the general vector field inside a real (finite) solenoid, using only the magnitude of the field along the symmetry axis. Our method does not require integration or knowledge of the current distribution, and is presented through practical examples, including a non-uniform finite solenoid used to produce cold atomic beams via laser cooling. These examples allow educators to discuss the non-trivial calculation of fields off-axis using concepts familiar to most students, while offering the opportunity to introduce important advancements of current modern research.

  3. A Deep Analysis of the Magnetic Field Produced by a Current-Carrying Straight Solenoid%长直螺线管磁场的深入分析

    曾晓英; 杨昌虎; 杨昶

    2001-01-01

    将长直螺线管磁场看作直线电流磁场和圆线圈电流磁场迭加。在此基础上,对螺线管磁场进行了深入分析和精确计算,给出了一般情形下近似描述长直螺线管磁场需满足的结构条件。%Decomposing the magnetic filed of a current-carrying strainght solenoid into that of straight current and that of circular curr ent, deep analysis and exact calculation of the field are proposed, and the approximation conditions have been derived for the description of the magnetic field of a straight solenoid in simplified case.

  4. Simple analysis of off-axis solenoid fields using the scalar magnetostatic potential: application to a Zeeman-slower for cold atoms

    Muniz, Sérgio R.; Bhattacharya, M.; Bagnato, Vanderlei S.

    2010-01-01

    In a region free of currents, magnetostatics can be described by the Laplace equation of a scalar magnetic potential, and one can apply the same methods commonly used in electrostatics. Here we show how to calculate the general vector field inside a real (finite) solenoid, using only the magnitude of the field along the symmetry axis. Our method does not require integration or knowledge of the current distribution, and is presented through practical examples, including a non-uniform finite so...

  5. Short Circuit Analysis of Fuel Solenoid Valve in Engine%发动机燃油电磁阀短路原因分析

    张玉龙; 郑莹; 熊华; 麻立晶

    2015-01-01

    A fuel solenoid valve in engine couldn’ t function properly during service. The failure cause of the solenoid value was analyzed using fault tree. First, the possible causes leading to the failure of the solenoid value were analyzed from top to bottom. Then the exact cause for the failure was found out by analyzing the fault phenomenon and testing data as well as on-spot investigation. Finally, the fault recurred by simulation experiment. The results show that the cause for the short circuit of the fuel solenoid valve is that reverse breakdown occurred while the diode was in use.%采用故障树分析的方法对发动机燃油电磁阀在使用中发生故障的原因进行分析。首先以电磁阀不工作的故障作为分析目标,通过由上向下的故障因果逻辑分析,逐层找出导致故障发生的所有必要而充分的直接原因和原因组合。再通过故障现象、试验数据以及故障现场调查等手段对故障原因进行定位,最后通过故障模拟试验,使故障再现,确定了造成燃油电磁阀短路的故障的原因为二极管在使用中出现反向击穿。

  6. Research on the CAT System for Hydraulic Valve Solenoid%液压阀用电磁铁CAT系统的开发

    杨璐; 聂崇嘉

    2001-01-01

    以液压阀用电磁铁试验台计算机辅助测试(CAT)系统的开发实践为基础,着重分析了测试软件在实现数据采集与处理、曲线输出功能等方面的程序设计方法和思路.在分析CAT软件设计共性(数据采集卡编程与数据预处理等等)的同时,阐述了针对电磁铁这一特定CAT对象所采取的测试方法.CAT技术的引入与传统的"试验台+函数记录仪"测试模式相比较,在便捷性及提高测试精度方面均具有突出的优点,从而可以高效精确地反映电磁铁的静特性.%The static performance of solenoid as displacement-power performance is important to hydraulic direction valve. This paper analyzes the design method about solenoid computer aided test software on the base of the practice for certain CAT system used for solenoid test bed. The programming methods and thoughts about how to achieve data acquisition-processing and test curve outputting are discussed emphatically, such common programming performance as application of data acquiring card and data pre-processing is analyzed also while showing special test method about solenoid. Application of computer aided test technology can acqure accurate static performance efficiently and improve test precision greatly. It is a first-rank substitution for early test model composed of x-y record and test bed.

  7. PULSE AMPLITUDE DISTRIBUTION RECORDER

    Cowper, G.

    1958-08-12

    A device is described for automatica1ly recording pulse annplitude distribution received from a counter. The novelty of the device consists of the over-all arrangement of conventional circuit elements to provide an easy to read permanent record of the pulse amplitude distribution during a certain time period. In the device a pulse analyzer separates the pulses according to annplitude into several channels. A scaler in each channel counts the pulses and operates a pen marker positioned over a drivable recorder sheet. Since the scalers in each channel have the sanne capacity, the control circuitry permits counting of the incoming pulses until one scaler reaches capacity, whereupon the input is removed and an internal oscillator supplies the necessary pulses to fill up the other scalers. Movement of the chart sheet is initiated wben the first scaler reaches capacity to thereby give a series of marks at spacings proportional to the time required to fill the remaining scalers, and accessory equipment marks calibration points on the recorder sheet to facilitate direct reading of the number of external pulses supplied to each scaler.

  8. Pulsed Plasma Electron Sources

    Krasik, Yakov

    2008-11-01

    Pulsed (˜10-7 s) electron beams with high current density (>10^2 A/cm^2) are generated in diodes with electric field of E > 10^6 V/cm. The source of electrons in these diodes is explosive emission plasma, which limits pulse duration; in the case E Hadas and Ya. E. Krasik, Europhysics Lett. 82, 55001 (2008).

  9. Research on Key Factors and Their Interaction Effects of Electromagnetic Force of High-Speed Solenoid Valve

    Fan, Liyun; Xu, De; Ma, Xiuzhen; Song, Enzhe

    2014-01-01

    Analysis consisting of numerical simulations along with lab experiments of interaction effects between key parameters on the electromagnetic force based on response surface methodology (RSM) has been also proposed to optimize the design of high-speed solenoid valve (HSV) and improve its performance. Numerical simulation model of HSV has been developed in Ansoft Maxwell environment and its accuracy has been validated through lab experiments. Effect of change of core structure, coil structure, armature structure, working air gap, and drive current on the electromagnetic force of HSV has been analyzed through simulation model and influence rules of various parameters on the electromagnetic force have been established. The response surface model of the electromagnetic force has been utilized to analyze the interaction effect between major parameters. It has been concluded that six interaction factors including working air gap with armature radius, drive current with armature thickness, coil turns with side pole radius, armature thickness with its radius, armature thickness with side pole radius, and armature radius with side pole radius have significant influence on the electromagnetic force. Optimal match values between coil turns and side pole radius; armature thickness and side pole radius; and armature radius and side pole radius have also been determined. PMID:25243217

  10. A fully conservative Eulerian–Lagrangian method for a convection–diffusion problem in a solenoidal field

    Arbogast, Todd

    2010-05-01

    Tracer transport is governed by a convection-diffusion problem modeling mass conservation of both tracer and ambient fluids. Numerical methods should be fully conservative, enforcing both conservation principles on the discrete level. Locally conservative characteristics methods conserve the mass of tracer, but may not conserve the mass of the ambient fluid. In a recent paper by the authors [T. Arbogast, C. Huang, A fully mass and volume conserving implementation of a characteristic method for transport problems, SIAM J. Sci. Comput. 28 (2006) 2001-2022], a fully conservative characteristic method, the Volume Corrected Characteristics Mixed Method (VCCMM), was introduced for potential flows. Here we extend and apply the method to problems with a solenoidal (i.e., divergence-free) flow field. The modification is a computationally inexpensive simplification of the original VCCMM, requiring a simple adjustment of trace-back regions in an element-by-element traversal of the domain. Our numerical results show that the method works well in practice, is less numerically diffuse than uncorrected characteristic methods, and can use up to at least about eight times the CFL limited time step. © 2010 Elsevier Inc.

  11. Field trapping of Y-Ba-Cu-O single grain rings joined to form the geometry of a solenoid

    Shi, Y; Dennis, A R; Xu, Z; Campbell, A M; Cardwell, D A [Superconductivity Group, Engineering Department, University of Cambridge, Cambridge CB2 1PZ (United Kingdom); Hari Babu, N, E-mail: ys206@cam.ac.u [Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University, West London UB8 3PH (United Kingdom)

    2010-04-15

    Large, single grain RE-Ba-Cu-O ((RE)BCO, where RE is a light rare earth element or yttrium) bulk superconductors have significant potential for a variety of engineering applications and are of considerable importance for theoretical research due to their ability to trap magnetic fields that are up to an order of magnitude higher than those generated by conventional, iron-based magnets. However, it is difficult to grow (RE)BCO in the form of very large grains or in the complex shapes and geometries that are required typically for practical devices and theoretical research. We report the fabrication and properties of a stack of rings (in the geometry of a solenoid) of YBCO single grains joined by a self-flux method. The trapped field at the top surface of the joined stack and within the resulting cylindrical cavity has been measured and the results compared with the predictions from a theoretical model that combines the Campbell equation and the Kim model.

  12. Improving sintered NdFeB permanent magnets by powder compaction in a 9 T superconducting solenoid

    Mulcahy, T. M.; Hull, J. R.; Rozendaal, E.; Wise, J. H.; Turner, L. R.

    2003-05-01

    Commercial-grade magnet powder (Magnequench UG) was axial die pressed in the 76.2 mm warm bore of a 9 T superconducting solenoid. Otherwise, processing was performed as part of normal factory operations. This pressing was done to improve the alignment of the anisotropic single-crystal particles of the compact and, thus, the remanent magnetization of the sintered cylindrical permanent magnets (12.7 mm diameter). Although the press was operated in batch mode for this proof-of-concept study, its design enables automated production. Improvements of up to 8% in magnetization and 16% in energy products were obtained, as the alignment field H was increased above the 2 T maximum field of electromagnets used in industry. The greatest improvements were obtained for magnets with the smallest length-to-diameter ratios, L/D<0.5. The production of quality magnets in this near-final-shape size range is currently being pursued by industry to eliminate expensive machining steps. To understand the potential for 2-8 T alignment fields to overcome the distortions created in the otherwise uniform field by the self-field of short compacts, electromagnetic code (Opera) calculations were made. A simple material model was used to predict the distortions. The trends in the predicted field-line inclinations, with L/D and H, compare to trends in the improvement of the magnetic properties.

  13. Analysis and simulation of magnetic field of a long straight solenoid%长直螺线管的电磁场分析与仿真

    陈红; 侯国栋

    2013-01-01

    根据电磁感应定律和螺线管电流磁场的特点,建立长直螺线管内部和表面的磁场的有限元模型.依据比奥-萨法尔定律和安培环路定理,对长直螺线管磁场进行理论分析和数学推导,得到其磁场分布的特点及其解析解.利用Ansoft Maxwell 3D工程电磁场有限元软件对其进行仿真,验证了结果的一致性及利用ANSYS软件进行电磁场分析的直观性和便利性.%According to the law of electromagnetic induction and the characteristics of current magnetic field of solenoid, a finite element model of the magnetic field on the surface or the interior of long straight solenoid was established. By means of theoretical deduction and numerical analysis based on the law of biot savart and Ampere circuital theorem of magnetic field in a straight solenoid, the characteristics of distribution of magnetic field and its analytical solution were obtained. The simulation was carried out on using of Ansoft Maxwell 3 D engineering electromagnetic field finite element software, the consistency of the result and the intuitive and convenient of using ANSYS software for electromagnetic field analysis were verified.

  14. Pulsed electron beam precharger

    Finney, W.C. (ed.); Shelton, W.N.

    1990-01-01

    Florida State University is investigating the concept of pulsed electron beams for fly ash precipitation. This report describes the results and data on three of the subtasks of this project and preliminary work only on the remaining five subtasks. Described are the modification of precharger for pulsed and DC energization of anode; installation of the Q/A measurement system; and modification and installation of pulsed power supply to provide both pulsed and DC energization of the anode. The other tasks include: measurement of the removal efficiency for monodisperse simulated fly ash particles; measurement of particle charge; optimization of pulse energization schedule for maximum removal efficiency; practical assessment of results; and measurement of the removal efficiency for polydisperse test particles. 15 figs., 1 tab. (CK)

  15. Pulse Distortion in Saturated Fiber Optical Parametric Chirped Pulse Amplification

    Lali-Dastjerdi, Zohreh; Da Ros, Francesco; Rottwitt, Karsten

    2012-01-01

    Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation.......Fiber optical parametric chirped pulse amplification is experimentally compared for different chirped pulses in the picosecond regime. The amplified chirped pulses show distortion appearing as pedestals after recompression when the amplifier is operated in saturation....

  16. Analysis of the electromagnetic field of direct action solenoid valve%直动电磁阀磁场特性分析

    刘潜峰; 薄涵亮; 秦本科

    2009-01-01

    The Hydraulic Control Rod Drive Technology (HCRDT) is a newly invented patent of the Institute of Nuclear and New Energy Technology, Tsinghua University with HCRDT's independent intellectual property rights. The integrated valve which is made up of three direct action solenoid valves is the key part of this technology, so the performance of the solenoid valve directly affects the function of the integrated valve and the HCRDT. Based on the abnormal conditions occurring in the operation of the Control Rod Hydraulic Drive System, the electromagnetic field of the direct action solenoid valve is analyzed using the ANSYS software. The result shows that the incorrect use of the magnetic material causes the change of magnetic circuit and the reverse of the magnetic force direction in some conditions, which leads to the malfunction of the solenoid valve and the Control Rod Hydraulic Drive System. Further more, the design of the direct action solenoid valve can be optimized by the analysis of electromagnetic field.%控制棒水压驱动技术是清华大学核能与新能源技术研究院具有自主知识产权的一项新型发明专利技术.组合阀属于该项技术的关键部件,组合阀是由三个直动电磁阀组成,电磁阀的性能直接影响组合阀的性能,从而影响控制棒水压驱动技术的运行性能.本文就控制棒水压驱动系统运行过程中所出现的异常工况,运用ANSYS电磁场分析软件,对其直动电磁阀的多种运行工况进行了电磁场特性分析.分析结果表明:导磁材料的不当使用形成磁路的改变,引起某些工况下磁力反向,使电磁阀在特定情况下出现故障,进而造成控制棒水压驱动系统异常;通过电磁场特性分析可以进一步优化直动电磁阀的设计.

  17. Short-pulse, compressed ion beams at the Neutralized Drift Compression Experiment

    Seidl, P. A.; Barnard, J. J.; Davidson, R. C.; Friedman, A.; Gilson, E. P.; Grote, D.; Ji, Q.; Kaganovich, I. D.; Persaud, A.; Waldron, W. L.; Schenkel, T.

    2016-05-01

    We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted on the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynamics of radiation-induced damage in materials with pump-probe experiments, and to stabilize novel metastable phases of materials when short-pulse heating is followed by rapid quenching. First experiments used a lithium ion source; a new plasma-based helium ion source shows much greater charge delivered to the target.

  18. Non-Contact Thrust Stand Calibration Method for Repetitively-Pulsed Electric Thrusters

    Wong, Andrea R.; Toftul, Alexandra; Polzin, Kurt A.; Pearson, J. Boise

    2011-01-01

    A thrust stand calibration technique for use in testing repetitively-pulsed electric thrusters for in-space propulsion has been developed and tested using a modified hanging pendulum thrust stand. In the implementation of this technique, current pulses are applied to a solenoidal coil to produce a pulsed magnetic field that acts against the magnetic field produced by a permanent magnet mounted to the thrust stand pendulum arm. The force on the magnet is applied in this non-contact manner, with the entire pulsed force transferred to the pendulum arm through a piezoelectric force transducer to provide a time-accurate force measurement. Modeling of the pendulum arm dynamics reveals that after an initial transient in thrust stand motion the quasisteady average deflection of the thrust stand arm away from the unforced or zero position can be related to the average applied force through a simple linear Hooke s law relationship. Modeling demonstrates that this technique is universally applicable except when the pulsing period is increased to the point where it approaches the period of natural thrust stand motion. Calibration data were obtained using a modified hanging pendulum thrust stand previously used for steady-state thrust measurements. Data were obtained for varying impulse bit at constant pulse frequency and for varying pulse frequency. The two data sets exhibit excellent quantitative agreement with each other as the constant relating average deflection and average thrust match within the errors on the linear regression curve fit of the data. Quantitatively, the error on the calibration coefficient is roughly 1% of the coefficient value.

  19. Generation of Helical and Axial Magnetic Fields by the Relativistic Laser Pulses in Under-dense Plasma: Three-Dimensional Particle-in-Cell Simulation

    Zheng, Chun-Yang; Zhu, Shao-Ping; He, Xian-Tu

    2002-07-01

    The quasi-static magnetic fields created in the interaction of relativistic laser pulses with under-dense plasmas have been investigated by three-dimensional particle-in-cell simulation. The relativistic ponderomotive force can drive an intense electron current in the laser propagation direction, which is responsible for the generation of a helical magnetic field. The axial magnetic field results from a difference beat of wave-wave, which drives a solenoidal current. In particular, the physical significance of the kinetic model for the generation of the axial magnetic field is discussed.

  20. WE-G-17A-07: Investigation of the Influence of the Electron Return Effect (ERE) On the Dose Distribution in Rectal Cancer Patients On a 1.5T MR-Linac

    Uilkema, S; Heide, U; Nijkamp, J [NKI, Amsterdam, Zuid Holland (Netherlands); Sonke, J [Netherlands Cancer Institute, Amsterdam (Netherlands); Moreau, M [Elekta, Inc, Verona, WI (Italy)

    2014-06-15

    Purpose: The purpose of this planning study is to investigate the influence of the ERE on the day-to-day dose distribution in rectal cancer patients, where changes in gas-pockets frequently occur. Methods: Daily CT scans of 5 patients treated neo-adjuvant with 5x5Gy for rectal cancer were used. We optimized two plans on the planning CT (Monaco, 1 mm3 dosegrid), a conventional 7-field 6MV IMRT plan (Dconv) and a plan in the presence of a 1.5T field (Dmrl). We recalculated the plans on all repeat-CT scans and evaluated under/over-dosage of the daily CTVs. Changes of more than 1% were considered significant. In the bowel area, we investigated the relative dose changes due to the ERE, where the contribution of the ERE was separated from other effects such as attenuation. Results: Both plans were comparable and compliant with ICRU 62 for all patients. For 2 fractions in one patient under-dosage in the CTV was significant, due to a disappearing gas-pocket. Here the V95 was 96.82 and 97.36% in in Dmrl compared to 98.85 and 98.66% in Dconv, respectively. For 3 fractions in another patient appearing gas-pockets resulted in significant over-dosage of the CTV. In these fractions the V107 was 1.88–2.68% in Dmrl compared to 0.33–1.27% in Dconv. In the bowel area the dose changes attributable to the ERE were approximately ± 5% in 1cc, at low dose levels. Conclusion: We were able to calculate acceptable treatment plans with and without a magnetic field. The ERE was present in the Dmrl, but the volumetric effect within the CTV was limited. Outside the CTV relative dose differences were similar, but on small volumes at lower, less relevant dose levels. This suggests that there is no clinical relevant ERE on dose distributions in rectal cancer patients on a 1.5T MR-Linac.

  1. Free-breathing radial volumetric interpolated breathhold examination vs breath-hold cartesian volumetric interpolated breath-hold examination magnetic resonance imaging of the liver at 1.5T

    Sireesha Yedururi; HyunSeon C Kang; Wei Wei; Nicolaus A Wagner-Bartak; Leonardo P Marcal; R Jason Stafford; Brandy J Willis; Janio Szklaruk

    2016-01-01

    AIM: To compare breath-hold cartesian volumetric interpolated breath-hold examination(cVIBE) and freebreathing radial VIBE(rVIBE) and determine whether rVIBE could replace cVIBE in routine liver magnetic resonance imaging(MRI).METHODS: In this prospective study, 15 consecutive patients scheduled for routine MRI of the abdomen underwent pre- and post-contrast breath-hold cVIBE imaging(19 s acquisition time) and free-breathing rVIBE imaging(111 s acquisition time) on a 1.5T Siemens scanner. Three radiologists with 2, 4, and 8 years post-fellowship experience in abdominal imaging evaluated all images. The radiologists were blinded to the sequence types, which were presented in a random order for each patient. For each sequence, the radiologists scored the cVIBE and rVIBE images for liver edge sharpness, hepatic vessel clarity, presence of artifacts, lesion conspicuity, fat saturation, and overall image quality using a five-point scale. RESULTS: Compared to rVIBE, cVIBE yielded significantly(P < 0.001) higher scores for liver edge sharpness(mean score, 3.87 vs 3.37), hepatic-vessel clarity(3.71 vs 3.18), artifacts(3.74 vs 3.06), lesion conspicuity(3.81 vs 3.2), and overall image quality(3.91 vs 3.24). cVIBE and rVIBE did not significantly differ in quality of fat saturation(4.12 vs 4.03, P = 0.17). The inter-observer variability with respect to differences between rVIBE and cVIBE scores was close to zero compared to random error and inter-patient variation. Quality of rVIBE images was rated as acceptable for all parameters. CONCLUSION: rVIBE cannot replace cVIBE in routine liver MRI. At 1.5T, free-breathing rVIBE yields acceptable, although slightly inferior image quality compared to breath-hold cVIBE.

  2. Pulse joining cartridges

    Golovashchenko, Sergey Fedorovich; Bonnen, John Joseph Francis

    2016-08-23

    A pulsed joining tool includes a tool body that defines a cavity that receives an inner tubular member and an outer tubular member and a pulse joining cartridge. The tubular members are nested together with the cartridge being disposed around the outer tubular member. The cartridge includes a conductor, such as a wire or foil, that extends around the outer tubular member and is insulated to separate a supply segment from a return segment. A source of stored electrical energy is discharged through the conductor to join the tubular members with an electromagnetic force pulse.

  3. Efficient Pulsed Quadrupole

    Petzenhauser, I.; Spiller, P.; Tenholt, C.

    2016-01-01

    In order to raise the focusing gradient in case of bunched beam lines, a pulsed quadrupole was designed. The transfer channels between synchrotrons as well as the final focusing for the target line are possible applications. The quadrupole is running in a pulsed mode, which means an immense saving of energy by avoiding standby operation. Still the high gradients demand high currents. Hence a circuit had to be developed which is able to recover a significant amount of the pulsing energy for following shots. The basic design of the electrical circuit of the quadrupole is introduced. Furthermore more energy efficient circuits are presented and the limits of adaptability are considered.

  4. DogPulse

    Skovgaard, Christoffer; Thomsen, Josephine Raun; Verdezoto, Nervo;

    2015-01-01

    This paper presents DogPulse, an ambient awareness system to support the coordination of dog walking among family members at home. DogPulse augments a dog collar and leash set to activate an ambient shape-changing lamp and visualize the last time the dog was taken for a walk. The lamp gradually...... changes its form and pulsates its lights in order to keep the family members aware of the dog walking activity. We report the iterative prototyping of DogPulse, its implementation and its preliminary evaluation. Based on our initial findings, we present the limitations and lessons learned as well...

  5. Pulse measurement apparatus and method

    Marciante, John R.; Donaldson, William R.; Roides, Richard G.

    2011-10-25

    An embodiment of the invention is directed to a pulse measuring system that measures a characteristic of an input pulse under test, particularly the pulse shape of a single-shot, nano-second duration, high shape-contrast optical or electrical pulse. An exemplary system includes a multi-stage, passive pulse replicator, wherein each successive stage introduces a fixed time delay to the input pulse under test, a repetitively-gated electronic sampling apparatus that acquires the pulse train including an entire waveform of each replica pulse, a processor that temporally aligns the replicated pulses, and an averager that temporally averages the replicated pulses to generate the pulse shape of the pulse under test. An embodiment of the invention is directed to a method for measuring an optical or an electrical pulse shape. The method includes the steps of passively replicating the pulse under test with a known time delay, temporally stacking the pulses, and temporally averaging the stacked pulses. An embodiment of the invention is directed to a method for increasing the dynamic range of a pulse measurement by a repetitively-gated electronic sampling device having a rated dynamic range capability, beyond the rated dynamic range of the sampling device; e.g., enhancing the dynamic range of an oscilloscope. The embodied technique can improve the SNR from about 300:1 to 1000:1. A dynamic range enhancement of four to seven bits may be achieved.

  6. Plasma current start-up experiments without a central solenoid in the iron core STOR-M tokamak

    Mitarai, O.; Tomney, G.; Rohollohi, A.; Lewis, E.; McColl, D.; Xiao, C.; Hirose, A.

    2015-06-01

    Reproducible plasma current start-up without a central solenoid (CS) has been demonstrated using the outer ohmic heating (OH) coils in the iron core STOR-M tokamak (Mitarai et al 2014 Fusion Eng. Des. 89 2467-71). Although the outer OH coil current saturates the iron core eventually, it has been demonstrated that the plasma current can be maintained during the iron core saturation phase. In this work, further studies have been conducted to investigate the effects of the turn number of the outer OH coils (N = 4 or N = 6) in the CS-less discharges and to evaluate the plasma stability with respect to the n-decay index of the vertical magnetic field. For the loose coupling of the iron core with N = 4 turns, the plasma current can be sustained after the additional third capacitor bank is applied near the iron core saturation phase, showing the slow transition from the unsaturated to the partially saturated phase. For the case of stronger coupling of N = 6 turns, the plasma current is increased at the same fast bank voltage, but the main discharge is shortened from 35 to 20 ms. As the magnetizing current is smaller due to stronger coupling between the OH coils and the plasma current, the transition from the unsaturated to the saturated phase is slightly difficult at present. The present experimental results suggest a feasible operation scenario in a future spherical tokamak (ST) at least using loose iron core coupling for smoother transition from the unsaturated to the saturated iron core phase. Thus, a reliable plasma current start-up by the outer OH coils and the current ramp-up to a steady state by additional heating power and vertical field coils could be considered as an operation scenario for future ST reactors with an iron core transformer.

  7. Pulse subtraction Doppler

    Mahue, Veronique; Mari, Jean Martial; Eckersley, Robert J.; Caro, Colin G.; Tang, Meng-Xing

    2010-01-01

    Recent advances have demonstrated the feasibility of molecular imaging using targeted microbubbles and ultrasound. One technical challenge is to selectively detect attached bubbles from those freely flowing bubbles and surrounding tissue. Pulse Inversion Doppler is an imaging technique enabling the selective detection of both static and moving ultrasound contrast agents: linear scatterers generate a single band Doppler spectrum, while non-linear scatterers generate a double band spectrum, one being uniquely correlated with the presence of contrast agents and non-linear tissue signals. We demonstrate that similar spectrums, and thus the same discrimination, can be obtained through a Doppler implementation of Pulse Subtraction. This is achieved by reconstructing a virtual echo using the echo generated from a short pulse transmission. Moreover by subtracting from this virtual echo the one generated from a longer pulse transmission, it is possible to fully suppress the echo from linear scatterers, while for non-linear scatterers, a signal will remain, allowing classical agent detection. Simulations of a single moving microbubble and a moving linear scatterer subject to these pulses show that when the virtual echo and the long pulse echo are used to perform pulsed Doppler, the power Doppler spectrum allows separation of linear and non-linear moving scattering. Similar results are obtained on experimental data acquired on a flow containing either microbubble contrast agents or linear blood mimicking fluid. This new Doppler method constitutes an alternative to Pulse Inversion Doppler and preliminary results suggest that similar dual band spectrums could be obtained by the combination of any non-linear detection technique with Doppler demodulation.

  8. Pulsed spallation Neutron Sources

    Carpenter, J.M. [Argonne National Lab., IL (United States)

    1994-12-31

    This paper reviews the early history of pulsed spallation neutron source development at Argonne and provides an overview of existing sources world wide. A number of proposals for machines more powerful than currently exist are under development, which are briefly described. The author reviews the status of the Intense Pulsed Neutron Source, its instrumentation, and its user program, and provides a few examples of applications in fundamental condensed matter physics, materials science and technology.

  9. Cumulative "roof effect" in high-resolution in vivo 31P NMR spectra of human calf muscle and the Clebsch-Gordan coefficients of ATP at 1.5 T.

    Schröder, Leif; Schmitz, Christian; Bachert, Peter

    2005-05-01

    NMR spectra of non-weakly coupled spin systems exhibit asymmetries in line intensities known as "roof effect" in 1D spectroscopy. Due to limited spectral resolution, this effect has not been paid much attention so far in in vivo spectroscopy. But when high-quality spectra are obtained, this effect should be taken into account to explain the quantum-mechanical fine structure of the system. Adenosine 5'-triphosphate (ATP) represents a 31P spin system with multiple line splittings which are caused by J-couplings of medium strength at 1.5 T. We analyzed the ATP roof effect in vivo, especially for the beta-ATP multiplet. The intensities of its outer resonances deviate by ca. 12.5% from a symmetrical triplet. As this asymmetry reflects the transition from Paschen-Back to Zeeman effect with total spin that is largely broken up, the Clebsch-Gordan coefficients of the system can be indicated in analogy to the hyperfine structure of hydrogen. Taking the roof effect into account, the chi2 of fitting in vivo ATP resonances is reduced by ca. 9% (p<0.005).

  10. Cumulative “roof effect” in high-resolution in vivo 31P NMR spectra of human calf muscle and the Clebsch Gordan coefficients of ATP at 1.5 T

    Schröder, Leif; Schmitz, Christian; Bachert, Peter

    2005-05-01

    NMR spectra of non-weakly coupled spin systems exhibit asymmetries in line intensities known as "roof effect" in 1D spectroscopy. Due to limited spectral resolution, this effect has not been paid much attention so far in in vivo spectroscopy. But when high-quality spectra are obtained, this effect should be taken into account to explain the quantum-mechanical fine structure of the system. Adenosine 5'-triphosphate (ATP) represents a 31P spin system with multiple line splittings which are caused by J-couplings of medium strength at 1.5 T. We analyzed the ATP roof effect in vivo, especially for the β-ATP multiplet. The intensities of its outer resonances deviate by ca. 12.5% from a symmetrical triplet. As this asymmetry reflects the transition from Paschen-Back to Zeeman effect with total spin that is largely broken up, the Clebsch-Gordan coefficients of the system can be indicated in analogy to the hyperfine structure of hydrogen. Taking the roof effect into account, the χ2 of fitting in vivo ATP resonances is reduced by ca. 9% ( p < 0.005).

  11. Contrast-enhanced dynamic MRI protocol with improved spatial and time resolution for in vivo microimaging of the mouse with a 1.5-T body scanner and a superconducting surface coil.

    Ginefri, Jean-Christophe; Poirier-Quinot, Marie; Robert, Philippe; Darrasse, Luc

    2005-02-01

    Magnetic resonance imaging (MRI) is well suited for small animal model investigations to study various human pathologies. However, the assessment of microscopic information requires a high-spatial resolution (HSR) leading to a critical problem of signal-to-noise ratio limitations in standard whole-body imager. As contrast mechanisms are field dependent, working at high field do not allow to derive MRI criteria that may apply to clinical settings done in standard whole-body systems. In this work, a contrast-enhanced dynamic MRI protocol with improved spatial and time resolution was used to perform in vivo tumor model imaging on the mouse at 1.5 T. The needed sensitivity is provided by the use of a 12-mm superconducting surface coil operating at 77 K. High quality in vivo images were obtained and revealed well-defined internal structures of the tumor. A 3-D HSR sequence with voxels of 59x59x300 microm3 encoded within 6.9 min and a 2-D sequence with subsecond acquisition time and isotropic in-plane resolution of 234 microm were used to analyze the contrast enhancement kinetics in tumoral structures at long and short time scales. This work is a first step to better characterize and differentiate the dynamic behavior of tumoral heterogeneities.

  12. In Vivo Single Scan Detection of Both Iron-Labeled Cells and Breast Cancer Metastases in the Mouse Brain Using Balanced Steady-State Free Precession Imaging at 1.5 T

    Ribot, Emeline J.; Martinez-Santiesteban, Francisco M.; Simedrea, Carmen; Steeg, Patricia S.; Chambers, Ann F.; Rutt, Brian K.; Foster, Paula J.

    2012-01-01

    Purpose To simultaneously detect iron-labeled cancer cells and brain tumors in vivo in one scan, the balanced steady-state free precession (b-SSFP) imaging sequence was optimized at 1.5 T on mice developing brain metastases subsequent to the injection of micron-sized iron oxide particle-labeled human breast cancer cells. Materials and Methods b-SSFP sequence parameters (repetition time, flip angle, and receiver bandwidth) were varied and the signal-to-noise ratio, contrast between the brain and tumors, and the number of detected iron-labeled cells were evaluated. Results Optimal b-SSFP images were acquired with a 26 msec repetition time, 35° flip angle, and bandwidth of ±21 kHz. b-SSFP images were compared with T2-weighted 2D fast spin echo (FSE) and 3D spoiled gradient recalled echo (SPGR) images. The mean tumor-brain contrast-to-noise ratio and the ability to detect iron-labeled cells were the highest in the b-SSFP images. Conclusion A single b-SSFP scan can be used to visualize both iron-labeled cells and brain metastases. PMID:21698713

  13. Measurement of vertebral bone marrow lipid profile at 1.5-T proton magnetic resonance spectroscopy and bone mineral density at dual-energy X-ray absorptiometry: correlation in a swine model

    Di Leo, Giovanni; Fina, Laura [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Bandirali, Michele; Messina, Carmelo [Universita degli Studi di Milano, Scuola di Specializzazione in Radiodiagnostica, Milan (Italy); Sardanelli, Francesco [IRCCS Policlinico San Donato, Unita di Radiologia, San Donato Milanese (Italy); Universita degli Studi di Milano, Dipartimento di Scienze Biomediche per la Salute, San Donato Milanese (Italy)

    2014-08-15

    Bone marrow is mainly composed of red (hematopoietic) and yellow (fatty) components. Soon after the birth there is a physiological conversion of the bone marrow from red to yellow, so that the percentage of hematopoietic cells and adipocytes changes with aging. Although bone marrow adipogenesis is a physiologic process involving all mammals, recent studies showed an accelerated marrow adipogenesis associated with several chronic conditions, including osteoporosis [4] and diabetes mellitus. Moreover, this increased marrow fat is accompanied by a decrease in bone density. Marrow fat is therefore increasingly believed to influence the bone microenvironment. Diagnostic tools for quantitative measurement of bone marrow fat and bone mineral density (BMD) include proton magnetic resonance spectroscopy (MRS) and dual-energy Xray absorptiometry (DXA), respectively. Using MRS, an inverse relationship between vertebral bone marrow fat content and lumbar BMD has been demonstrated in patients affected with osteoporosis or with diabetes mellitus. In most studies, a quite standard MRS sequence has been used, with short echo times (TE) for the measurement of the bulk methylene. In this study we sought to optimize the MRS sequence in order to try to measure other fat components of the vertebral bone marrow at 1.5 T. For this purpose, we used an animal model that allowed long acquisition times and repeated measures. Moreover, we aimed at estimating in this model the relationship between vertebral bone marrow fat content at proton MRS and BMD at DXA.

  14. High-voltage pulse generator with inductive energy storage and thyratron

    Vereshchagin, N M

    2002-01-01

    The high-voltage pulse generator with the energy storage on the basis of the single layer solenoid with inductivity of 10-35 mu H is described. The TGI2-500/20 thyratron able of breaking reliably the current with the amplitude of 800-850 A was used as the current breaker. The voltage on the load is formed in two stages. The first stage is characterized by the voltage of 20-25 kV and the growth time of 150-200 m. At the second stage there takes place fast (approx 60 ns) formation of the voltage up 90 kV. The scheme of the charge quenching decreases the instability of the current breaker time

  15. High voltage pulse generator

    Fasching, George E.

    1977-03-08

    An improved high-voltage pulse generator has been provided which is especially useful in ultrasonic testing of rock core samples. An N number of capacitors are charged in parallel to V volts and at the proper instance are coupled in series to produce a high-voltage pulse of N times V volts. Rapid switching of the capacitors from the paralleled charging configuration to the series discharging configuration is accomplished by using silicon-controlled rectifiers which are chain self-triggered following the initial triggering of a first one of the rectifiers connected between the first and second of the plurality of charging capacitors. A timing and triggering circuit is provided to properly synchronize triggering pulses to the first SCR at a time when the charging voltage is not being applied to the parallel-connected charging capacitors. Alternate circuits are provided for controlling the application of the charging voltage from a charging circuit to be applied to the parallel capacitors which provides a selection of at least two different intervals in which the charging voltage is turned "off" to allow the SCR's connecting the capacitors in series to turn "off" before recharging begins. The high-voltage pulse-generating circuit including the N capacitors and corresponding SCR's which connect the capacitors in series when triggered "on" further includes diodes and series-connected inductors between the parallel-connected charging capacitors which allow sufficiently fast charging of the capacitors for a high pulse repetition rate and yet allow considerable control of the decay time of the high-voltage pulses from the pulse-generating circuit.

  16. A high current, short pulse electron source for wakefield accelerators

    Ho, Ching-Hung

    1992-12-31

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  17. A high current, short pulse electron source for wakefield accelerators

    Ho, Ching-Hung.

    1992-01-01

    Design studies for the generation of a high current, short pulse electron source for the Argonne Wakefield Accelerator are presented. An L-band laser photocathode rf gun cavity is designed using the computer code URMEL to maximize the electric field on the cathode surface for fixed frequency and rf input power. A new technique using a curved incoming laser wavefront to minimize the space charge effect near the photocathode is studied. A preaccelerator with large iris to minimize wakefield effects is used to boost the drive beam to a useful energy of around 20 MeV for wakefield acceleration experiments. Focusing in the photocathode gun and the preaccelerator is accomplished with solenoids. Beam dynamics simulations throughout the preaccelerator are performed using particle simulation codes TBCI-SF and PARMELA. An example providing a useful set of operation parameters for the Argonne Wakefield Accelerator is given. The effects of the sagitta of the curved beam and laser amplitude and timing jitter effects are discussed. Measurement results of low rf power level bench tests and a high power test for the gun cavity are presented and discussed.

  18. Development of a novel parallel-spool pilot operated high-pressure solenoid valve with high flow rate and high speed

    Dong, Dai; Li, Xiaoning

    2015-03-01

    High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system. However, traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously. A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system. A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design. Mathematical models of the opening process and flow rate of the valve are established. Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response. Corresponding formulas to solve 4 parts of the response time are derived. Key factors that influence the opening response time are analyzed. According to the mathematical model of the valve, a simulation of the opening process is carried out by MATLAB. Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve. Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool. The experimental results are in agreement with the simulated results, therefore the validity of the theoretical analysis is verified. Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa. The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s. According to the result of the load driving test, the valve can meet the demands of the driving system. The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

  19. Finite element computation of 2-D magnetic field of solenoid with current%通电螺线管2维磁场有限元计算

    彭斓; 杨中海; 胡权; 黄桃; 李斌

    2011-01-01

    Finite element computation of 2-D magnetic field of solenoid with current has been implemented. It adopted first or second order interpolation based finite element method to solve the 2-D magnetic field of the solenoid. The single solenoid model and the periodic structure model were analyzed and simulated. The results were compared with the results of Ansoft Maxwell 2D. It is shown that, compared with the first order interpolation based finite element method, the second order interpolation one has a faster convergence rate and a better accuracy on the axis of symmetry.%通过对通电螺线管磁系统理论分析,实现了通电螺线管2维磁场计算.该算法是采用一次、二次插值函数计算螺线管模型磁场的有限元算法,用于求解螺线管内外任意位置处的磁感应强度分布.实现了螺线管及周期结构的计算,并将结果与Ansoft Maxwell 2-D的计算结果进行了对比.结果表明:较一次插值函数有限元算法相比,二次插值函数算法在对称轴上轴向磁感应强度的分布更准确,体现了该算法的优越性,具有显著的工程应用价值.

  20. 不同端面结构电磁开关的电磁力分析%Electromagnetic force analysis of solenoid actuator with different end-structures

    夏利波; 吴建华

    2011-01-01

    Aiming at different end-structure of the solenoid actuator, the electromagnetic force of the solenoid actuator was analyzed using the finite element method ( FEM ) software ANSYS.The performance between the flattened structure and cone-type structure was compared based on learning basic principles.The suitable end-structures and different sizes-changes were analyzed by selecting.The influence of structure parameters on electromagnetic force such as chamfer length of the flattened structure core and angle changes of cone-type structure was calculated.Experiment results verifies the attraction force characteristic of solenoid actuator with different end-structures.The conclusion is useful for follow research.%针对"汽车起动机电磁开关的端而结构不同"问题,在了解电磁开关基本原理的基础上,利用ANSYS有限元软件,比较分析了平顶型结构和锥顶型结构电磁开关的性能特点,并选择合适的端面结构和不同的结构尺寸变化进行了进一步分析.计算了平顶型铁心倒角长度和锥顶型铁心锥角的结构参数对电磁力的影响.实验结果验证了不同端面结构电磁开关的吸力特性,该结果对电磁开关设计具有指导意义.

  1. 双电磁阀配置在石油化工装置中的应用%Brief Introduction of Dual Solenoid Valve Configuration at Petrochemical Unit

    范咏峰

    2011-01-01

    Safety is a critical issue at both engineering and operation of petrochemical unit, based on ALARP(As Low As Reasonably Practicable) principle, research on method of how to prevent mal-operation trip is obtained more and more attention, especially for case of huge economic loss. Appropriate redundancy design is widely adopted in petrochemical unit. A discussion is made on a dual solenoid valve configuration which can achieve redundant configuration of signal loop of on-off valve to reduce mal-operation trip due to cable break, analyze de-energization interlock and energization interlock, illustrate pneumatic hook-up and logic design of dual solenoid valve, briefly introduce dual solenoid valve operation philosophyand malfunction analysis, and its actual application.%安全性在石油化工装置设计与正常运行中起着很重要的作用,保证安全性的前提下按照ALARP经济分析评估的原则,如何避免误停车同样得到越来越多的重视,特别是针对误停车会带来较大经济损失的场合,适当的冗余设计在石油化工装置中被较广泛地采用.讨论了采用双电磁阀配置实现切断阀电磁阀信号线路的冗余配置,以减少因电缆断线引起的误停车.分析了失电联锁和得电联锁.列举了双电磁阀气路设计及逻辑设计,简介了电磁阀工作原理及故障分析,最后简要说明了实际设计中的应用.

  2. Development of a Novel Parallel-spool Pilot Operated High-pressure Solenoid Valve with High Flow Rate and High Speed

    DONG Dai; LI Xiaoning

    2015-01-01

    High-pressure solenoid valve with high flow rate and high speed is a key component in an underwater driving system. However, traditional single spool pilot operated valve cannot meet the demands of both high flow rate and high speed simultaneously. A new structure for a high pressure solenoid valve is needed to meet the demand of the underwater driving system. A novel parallel-spool pilot operated high-pressure solenoid valve is proposed to overcome the drawback of the current single spool design. Mathematical models of the opening process and flow rate of the valve are established. Opening response time of the valve is subdivided into 4 parts to analyze the properties of the opening response. Corresponding formulas to solve 4 parts of the response time are derived. Key factors that influence the opening response time are analyzed. According to the mathematical model of the valve, a simulation of the opening process is carried out by MATLAB. Parameters are chosen based on theoretical analysis to design the test prototype of the new type of valve. Opening response time of the designed valve is tested by verifying response of the current in the coil and displacement of the main valve spool. The experimental results are in agreement with the simulated results, therefore the validity of the theoretical analysis is verified. Experimental opening response time of the valve is 48.3 ms at working pressure of 10 MPa. The flow capacity test shows that the largest effective area is 126 mm2 and the largest air flow rate is 2320 L/s. According to the result of the load driving test, the valve can meet the demands of the driving system. The proposed valve with parallel spools provides a new method for the design of a high-pressure valve with fast response and large flow rate.

  3. Theory of Constraints Applied to Production Planning of Solenoid Valve%约束理论在电磁阀生产计划中的应用

    彭娜; 乔梅

    2015-01-01

    以电磁阀生产计划控制为研究对象 ,将约束理论引入生产系统 .通过生产类型和工艺路线分析 ,对可能存在瓶颈工序部件的各个工序进行工时统计、生产能力负荷比较后 ,找出阀门生产中的瓶颈工序 .运用DBR理论 ,对瓶颈工序建立"前拉后推"的生产计划编排方式 ,提高了瓶颈工序的生产效率 ,瓶颈工序的在制品堆积情况有所缓解 ,装配停工待料情况大大减少 ,电磁阀生产周期缩短了20% ,使得阀门能够按时出厂.%Take production planning and control of sole-noid valves as the object of the research ,and the theory of constraints(TOC)is used in manufacturing system.By analy-sis of types of manufactuing and production technological process ,statistics of total working hours for all the working procedures is made where bottleneck process parts may exist and after the comparision of production capacity load is made to find bottleneck working procedure.By making use of theo-ry of Drum-Buffer-Rope (DBR ) , the push-pull production plan as one mode of layout plan is set up to increase efficien-cy in bottleneck departments and decrease working process. Thus production time of solenoid valves is reduced by twenty percent and solenoid valves have been executed on schedule.

  4. In-depth compositional analysis of water-soluble and -insoluble organic substances in fine (PM2.5) airborne particles using ultra-high-resolution 15T FT-ICR MS and GC×GC-TOFMS.

    Choi, Jung Hoon; Ryu, Jijeong; Jeon, Sodam; Seo, Jungju; Yang, Yung-Hun; Pack, Seung Pil; Choung, Sungwook; Jang, Kyoung-Soon

    2017-03-05

    Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2.5) airborne particles collected during winter in Korea to better understand the elemental compositions and distributions of these compounds. To collect ultra-high-resolution mass profiles, we analyzed water-soluble and -insoluble organic compounds, extracted with water and dichloromethane, respectively, using an ultra-high-resolution 15 T Fourier transform ion cyclotron resonance (15T FT-ICR) mass spectrometer in positive ion mode (via both electrospray ionization [ESI] and atmospheric pressure photoionization [APPI] for water-extracts and via APPI for dichloromethane-extracts). In conjunction with the FT-ICR mass spectrometry (MS) data, subsequent two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) data were used to identify potentially hazardous organic components, such as polycyclic aromatic hydrocarbons. This analysis provided information on the sources of ambient particles collected during winter season and partial evidence of contributions to the acidity of organic content in PM2.5 particles. The compositional and structural features of water-soluble and -insoluble organic compounds from PM2.5 particles are important for understanding the potential impacts of aerosol-carried organic substances on human health and global ecosystems in future toxicological studies.

  5. A compact spin-exchange optical pumping system for 3He polarization based on a solenoid coil, a VBG laser diode, and a cosine theta RF coil

    Lee, Sungman; Kim, Jongyul; Moon, Myung Kook; Lee, Kye Hong; Lee, Seung Wook; Ino, Takashi; Skoy, Vadim R.; Lee, Manwoo; Kim, Guinyun

    2013-02-01

    For use as a neutron spin polarizer or analyzer in the neutron beam lines of the HANARO (High-flux Advanced Neutron Application ReactOr) nuclear research reactor, a 3He polarizer was designed based on both a compact solenoid coil and a VBG (volume Bragg grating) diode laser with a narrow spectral linewidth of 25 GHz. The nuclear magnetic resonance (NMR) signal was measured and analyzed using both a built-in cosine radio-frequency (RF) coil and a pick-up coil. Using a neutron transmission measurement, we estimated the polarization ratio of the 3He cell as 18% for an optical pumping time of 8 hours.

  6. Design of Driving Circuit for Injector Solenoid Valve Based on DSP%基于DSP的喷油器电磁阀驱动电路设计

    陈远; 肖兵

    2012-01-01

    According to the relationship between the electromagnetic force and current in the practical work of diesel engine fuel injection valve, a driving Circuit based on TMS320F28035 DSP was introduced in this paper. For the purpose of improved electromagnetic valve opening and closing speed, lower power consumption and simplified circuit. The circuit drives multiple solenoid valves using the 28035DSP interior integration's comparator module and the EPWM module. The solenoid valve high side uses 80 voltage and 24 voltage double power source time sharing driving technology, uses the PWM current feedback closed -loop control technology at the low side. Results show that this driving circuit will implement the peak current of 10A and the hold current of 5A control. Current characteristics of the solenoid valve meet the injector drive requirements. Obviously has promoted solenoid valve opening and closing speed, reduced the system energy consumption.%根据柴油发动机喷油电磁阀在实际工作中电磁力与电流的关系,设计出一种基于TMS320F28035DSP的柴油机电控喷油电磁阀的驱动电路,以达到提高电磁阀开启与关闭速度、降低能耗和简化电路的目的;驱动电路利用28035DSP内部集成的比较器模块和EPWM模块实现多个电磁阀的驱动,电磁阀高端采用80V高压和24V低压双电源分时驱动技术,电磁阀低端采用电流反馈PWM调制控制技术;试验结果表明:驱动电路实现了12A峰值电流和4A保持电流的电流控制,电流波形满足电磁阀驱动特性,显著提升了电磁阀开启与关闭速度,降低了系统能耗.

  7. Motions of CMS detector structures due to the magnetic field forces as observed by the Link alignment system during the test of the 4 T magnet solenoid

    Garcia-Moral, L.A.; Gomez, G.; Gonzalez-Sanchez, F.J.; Martinez-Rivero, C.; Matorras, F.; Rodrigo, T.; Martinez, P.; Scodellaro, L.; Vila, I.; Virto, A.L. [Instituto de Fisica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander (Spain); Sobron, M. [Instituto de Fisica de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander (Spain)], E-mail: sobron@ifca.unican.es; Alberdi, J.; Arce, P.; Barcala, J.M.; Calvo, E.; Ferrando, A.; Josa, M.I.; Molinero, A.; Navarrete, J.; Oller, J.C. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain)] (and others)

    2009-07-21

    This document describes results obtained from the Link alignment system data recorded during the Compact Muon Solenoid (CMS) Magnet Test. A brief description of the system is followed by a discussion of the detected relative displacements (from micrometres to centimetres) between detector elements and rotations of detector structures (from microradians to milliradians). Observed displacements are studied as functions of the magnetic field intensity. In addition, the reconstructed positions of active element sensors are compared to their positions as measured by photogrammetry and the reconstructed motions due to the magnetic field strength are described.

  8. Discharge pulse phenomenology

    Frederickson, A. R.

    1985-01-01

    A model was developed which places radiation induced discharge pulse results into a unified conceptual framework. Only two phenomena are required to interpret all space and laboratory results: (1) radiation produces large electrostatic fields inside insulators via the trapping of a net space charge density; and (2) the electrostatic fields initiate discharge streamer plasmas similar to those investigated in high voltage electrical insulation materials; these streamer plasmas generate the pulsing phenomena. The apparent variability and diversity of results seen is an inherent feature of the plasma streamer mechanism acting in the electric fields which is created by irradiation of the dielectrics. The implications of the model are extensive and lead to constraints over what can be done about spacecraft pulsing.

  9. Pulsed ELDOR detected NMR

    Schosseler, P.; Wacker, Th.; Schweiger, A.

    1994-07-01

    A pulsed EPR method for the determination of small hyperfine interactions in disordered systems is described. A selective preparation pulse of frequency ω mw(1) excites allowed and forbidden transitions, thereby burning spectral holes into the EPR line. The positions of the holes caused by the excitation of forbidden transitions correspond to the nuclear transition frequencies of the spin system. A selective detection pulse of frequency ω mw(2) creates an FID with integrated intensity proportional to the magnetization at frequency ω mw(2). The entire hole pattern is obtained by recording the integrated intensity of the FID while varying the frequency difference Δω mw=ω mw(1)-ω mw(2) step by step.

  10. Pulsed Artificial Electrojet Generation

    Papadopoulos, K.

    2008-12-01

    Traditional techniques for generating low frequency signals in the ULF/ELF range (.1-100 Hz) and rely on ground based Horizontal Electric Dipole (HED) antennas. It is, furthermore, well known that a Vertical Electric Dipole (VED) is by more than 50 dB more efficient than a HED with the same dipole current moment. However, the prohibitively long length of VED antennas in the ELF/ULF range coupled with voltage limitations due to corona discharge in the atmosphere make them totally impracticable. In this paper we discuss a novel concept, inspired by the physics of the equatorial electrojet, that allows for the conversion of a ground based HED to a VED in the E-region of the equatorial ionosphere with current moment comparable to the driving HED. The paper focuses in locations near the dip-equator, where the earth's magnetic is in predominantly in the horizontal direction. The horizontal electric field associated with a pulsed HED drives a large Hall current in the ionospheric E-region, resulting in a vertical current. It is shown that the pulsed vertical current in the altitude range 80-130 km, driven by a horizontal electric field of, approximately, .1 mV/m at 100 km altitude, is of the order of kA. This results in a pulsed VED larger than 106 A-m. Such a pulsed VED will drive ELF/ULF pulses with amplitude in excess of .1 nT at a lateral range larger than few hundred kilometers. This is by three orders of magnitude larger than the one expected by a HED with comparable current moment. The paper will conclude with the description of a sneak-through technique that allows for creating pulsed electric fields in the ionosphere much larger than expected from steady state oscillatory HED antennas.

  11. Pulsed Electron Holography

    Germann, Matthias; Escher, Conrad; Fink, Hans-Werner

    2013-01-01

    A technique of pulsed low-energy electron holography is introduced that allows for recording highly resolved holograms within reduced exposure times. Therefore, stacks of holograms are accumulated in a pulsed mode with individual acquisition times as short as 50 {\\mu}s. Subsequently, these holograms are aligned and finally superimposed. The resulting holographic record reveals previously latent high-order interference fringes and thereby pushing interference resolution into the sub-nanometer regime. In view of the non-damaging character of low-energy electrons, the method is of particular interest for structural analysis of fragile biomolecules.

  12. Pulse Doppler radar

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  13. Mixing characteristics of pulsed air-assist liquid jet into an internal subsonic cross-flow

    Lee, Inchul; Kang, Youngsu; Koo, Jaye

    2010-04-01

    Penetration depth, spray dispersion angle, droplet sizes in breakup processes and atomization processes are very important parameters in combustor of air-breathing engine. These processes will enhance air/fuel mixing inside the combustor. Experimental results from the pulsed air-assist liquid jet injected into a cross-flow are investigated. And experiments were conducted to a range of cross-flow velocities from 42˜136 m/s. Air is injected with 0˜300kPa, with air-assist pulsation frequency of 0˜20Hz. Pulsation frequency was modulated by solenoid valve. Phase Doppler Particle Analyzer(PDPA) was utilized to quantitatively measuring droplet characteristics. High-speed CCD camera was used to obtain injected spray structure. Pulsed air-assist liquid jet will offer rapid mixing and good liquid jet penetration. Air-assist makes a very fine droplet which generated mist-like spray. Pulsed air-assist liquid jet will introduce additional supplementary turbulent mixing and control of penetration depth into a cross-flow field. The results show that pulsation frequency has an effect on penetration, transverse velocities and droplet sizes. The experimental data generated in these studies are used for a development of active control strategies to optimize the liquid jet penetration in subsonic cross-flow conditions and predict combustion low frequency instability.

  14. Interaction of CO2 laser pulses with solid targets in magnetic fields

    Loter, N. G.; Halverson, W.; Lax, B.

    1981-08-01

    High-temperature plasmas were generated by focussing 225-J gain-switched CO2 laser pulses onto planar solid targets within the bore of a Bitter solenoid magnet. DC magnetic fields up to 100 kG were applied parallel to the laser propagation vector, partially confining a long plasma column streaming away from the target. Target materials included teflon (CF2), graphite, and Al. Soft x-ray diagnostics, including a dual-channel, time-resolving TAP crystal spectrometer, a pinhole camera, and differentially-filtered p-i-n diodes, were used to determine electron density, electron temperature, and axial and radial expansion characteristics of the plasma. From these measurements, it was deduced that effects of refraction became increasingly important as B was increased; furthermore, these effects were strongly dependent on target material. For all targets, refraction occurred late in the pulse when the radially confined plasmas left the focal volume. For teflon and aluminum targets, but not for the lower Z graphite targets, it was inferred that significant side scattering also occurred early in the pulse with sufficiently strong magnetic fields.

  15. Short-Pulse, Compressed Ion Beams at the Neutralized Drift Compression Experiment

    Seidl, Peter A; Davidson, Ronald C; Friedman, Alex; Gilson, Erik P; Grote, David; Ji, Qing; Kaganovich, I D; Persaud, Arun; Waldron, William L; Schenkel, Thomas

    2016-01-01

    We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted on the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynam...

  16. Short intense ion pulses for materials and warm dense matter research

    Seidl, Peter A., E-mail: PASeidl@lbl.gov [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Persaud, Arun; Waldron, William L. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Barnard, John J. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Davidson, Ronald C. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Friedman, Alex [Lawrence Livermore National Laboratory, Livermore, CA (United States); Gilson, Erik P. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Greenway, Wayne G. [Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Grote, David P. [Lawrence Livermore National Laboratory, Livermore, CA (United States); Kaganovich, Igor D. [Princeton Plasma Physics Laboratory, Princeton, NJ (United States); Lidia, Steven M.; Stettler, Matthew; Takakuwa, Jeffrey H.; Schenkel, Thomas [Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2015-11-11

    We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment-II at Lawrence Berkeley National Laboratory, by generating beam spots size with radius r<1 mm within 2 ns FWHM and approximately 10{sup 10} ions/pulse. To enable the short pulse durations and mm-scale focal spot radii, the 1.2 MeV Li{sup +} ion beam is neutralized in a 1.6-meter drift compression section located after the last accelerator magnet. An 8-Tesla short focal length solenoid compresses the beam in the presence of the large volume plasma near the end of this section before the target. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including selected topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Here we describe the accelerator commissioning and time-resolved ionoluminescence measurements of yttrium aluminum perovskite using the fully integrated accelerator and neutralized drift compression components.

  17. Development of gas pulsing system for electron cyclotron resonance ion sourcea)

    Hojo, S.; Honma, T.; Muramatsu, M.; Sakamoto, Y.; Sugiura, A.

    2008-02-01

    A gas-pulsing system for an electron cyclotron resonance ion source with all permanent magnets (Kei2 source) at NIRS has been developed and tested. The system consists of a small vessel (30ml) to reserve CH4 gas and two fast solenoid valves that are installed at both sides of the vessel. They are connected to each other and to the Kei2 source by using a stainless-steel pipe (4mm inner diameter), where the length of the pipe from the valve to the source is 60cm and the conductance is 1.2l /s. From the results of the test, almost 300eμA for a pulsed C4+12 beam was obtained at a Faraday cup in an extraction-beam channel with a pressure range of 4000Pa in the vessel. At this time, the valve has an open time of 10ms and the delay time between the valve open time and the application of microwave power is 100ms. In experiments, the conversion efficiency for input CH4 molecules to the quantity of extracted C4+12 ions in one beam pulse was found to be around 3% and the ratio of the total amount of the gas requirement was only 10% compared with the case of continuous gas provided in 3.3s of repetition in HIMAC.

  18. Short intense ion pulses for materials and warm dense matter research

    Seidl, Peter A; Lidia, Steven M; Persaud, Arun; Stettler, Matthew; Takakuwa, Jeffrey H; Waldron, William L; Schenkel, Thomas; Barnard, John J; Friedman, Alex; Grote, David P; Davidson, Ronald C; Gilson, Erik P; Kaganovich, Igor D

    2015-01-01

    We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment-II at Lawrence Berkeley National Laboratory, by generating beam spots size with radius r < 1 mm within 2 ns FWHM and approximately 10^10 ions/pulse. To enable the short pulse durations and mm-scale focal spot radii, the 1.2 MeV Li+ ion beam is neutralized in a 1.6-meter drift compression section located after the last accelerator magnet. An 8-Tesla short focal length solenoid compresses the beam in the presence of the large volume plasma near the end of this section before the target. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including selected topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Here we describe the accelerator commissioning and time-resolved ionoluminescence measurements of yttrium aluminium perovskite using the fully integrated accel...

  19. Solenoid Testing Facility

    Federal Laboratory Consortium — Current Configuration: Accommodate a device under test up to 2.8 m diameter, 0.7 m height and 15,000 lbs. weight. Up to 10 g/s, 4.5 K helium flow. Up to 250 A test...

  20. The Cmpact Muon Solenoid

    Cole, Jo

    2007-01-01

    "In 2007, the most energetic particle collider on Earth will begin operation, giving us a unique opportunity to observe events that have not been seen since less than a million-millionth of a second after the Big Bang."

  1. Optimal Bitter Coil Solenoid

    Kobelev, V

    2016-01-01

    Bitter coil is an electromagnet used for the generation of exceptionally strong magnetic fields. The upper bound of magnet flux density is restricted by several factors. One principal restriction is the high stresses due to Lorentz forces in the coil. The Lorentz forces generate the distributed body force, which acts as the pressure of magnetic field. The common radial thickness profile of the Bitter coil is constant. In this paper the possibility of optimization by means of non-constant radial thickness profile of the Bitter coil is studied. The close form expression for optimal thickness profile is obtained. Both designs are compared and the considerable improvement of magnetic flux density is demonstrated. Moreover, the optimal design improves the shape of cooling channels. Namely, the highest cross-section of cooling channel is at the most thermally loaded inner surface of the coil.

  2. SNMR pulse sequence phase cycling

    Walsh, David O; Grunewald, Elliot D

    2013-11-12

    Technologies applicable to SNMR pulse sequence phase cycling are disclosed, including SNMR acquisition apparatus and methods, SNMR processing apparatus and methods, and combinations thereof. SNMR acquisition may include transmitting two or more SNMR pulse sequences and applying a phase shift to a pulse in at least one of the pulse sequences, according to any of a variety cycling techniques. SNMR processing may include combining SNMR from a plurality of pulse sequences comprising pulses of different phases, so that desired signals are preserved and indesired signals are canceled.

  3. Design of A Solenoid Valve Control System Based on VxWorks%一种基于 VxWorks 的电磁阀控制系统设计

    张星; 刘巍; 张建国; 付道俊

    2016-01-01

    Solenoid valves are widely used in various control fields .As the control demand enhances ,designing a sole-noid valve control system with real-timing ,accuracy and reliability becomes a key question .This paper proposes a solenoid valve control system based on VxWorks ,describes its hardware and software design in detail .The result of tests shows that the control system is of high performance .%电磁阀广泛应用于各控制领域,随着对控制要求的不断提高,实时、准确、可靠的阀控系统是一大难题。论文提出一种基于 VxWorks 的阀件控制系统,详细介绍了其软硬件设计,并验证了其高性能。

  4. Solid-state pulse forming module with adjustable pulse duration

    Wang, Langning; Liu, Jinliang; Qiu, Yongfeng; Chu, Xu; Zhang, Qingmeng

    2017-03-01

    A new solid-state pulse forming module is described in this paper. The pulse forming module is fabricated on a glass ceramic substrate, with the dimension of 250 mm × 95 mm × 4 mm. By changing the copper strips used in the pulse forming modules, the pulse duration of the obtained pulsed can range from 80 ns to 140 ns. Both the simulation and tests show that the pulse forming module has a good pulse forming ability. Under a high voltage in microsecond's time, the new pulse forming modules can hold off a voltage up to 25 kV higher than that of the previous study. In addition, future optimization for the field enhancement near the thin electrode edge has been proposed and simulated.

  5. Pulse distortion in single-mode fibers. 3: Chirped pulses.

    Marcuse, D

    1981-10-15

    The theory of pulse distortion in single-mode fibers is extended to include laser sources that suffer a linear wavelength sweep (chirp) during the duration of the pulse. The transmitted pulse is expressed as a Fourier integral whose spectral function is given by an analytical expression in closed form. The rms width of the transmitted pulse is also expressed in closed form. Numerical examples illustrate the influence of the chirp on the shape and rms width of the pulse. A somewhat paradoxical situation exists. A given input pulse can be made arbitrarily short by a sufficiently large amount of chirping, and, after a given fiber length, this chirped pulse returns to its original width. But at this particular distance an unchirped pulse would be only [equiation] times longer. Thus chirping can improve the rate of data transmission by only 40%.

  6. Ultrafast optomechanical pulse picking

    Lilienfein, Nikolai; Holzberger, Simon; Pupeza, Ioachim

    2017-01-01

    State-of-the-art optical switches for coupling pulses into and/or out of resonators are based on either the electro-optic or the acousto-optic effect in transmissive elements. In high-power applications, the damage threshold and other nonlinear and thermal effects in these elements impede further improvements in pulse energy, duration, and average power. We propose a new optomechanical switching concept which is based solely on reflective elements and is suitable for switching times down to the ten-nanosecond range. To this end, an isolated section of a beam path is moved in a system comprising mirrors rotating at a high angular velocity and stationary imaging mirrors, without affecting the propagation of the beam thereafter. We discuss three variants of the concept and exemplify practical parameters for its application in regenerative amplifiers and stack-and-dump enhancement cavities. We find that optomechanical pulse picking has the potential to achieve switching rates of up to a few tens of kilohertz while supporting pulse energies of up to several joules.

  7. Downhole pulse tube refrigerators

    Swift, G.; Gardner, D. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

    1997-12-01

    This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

  8. Pulsed inductive HF laser

    Razhev, A M; Kargapol' tsev, E S [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Churkin, D S; Demchuk, S V [Novosibirsk State University, Novosibirsk (Russian Federation)

    2016-03-31

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H{sub 2} – F{sub 2}(NF{sub 3} or SF6{sub 6}) and He(Ne) – H{sub 2} – F{sub 2}(NF{sub 3} or SF{sub 6}) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%. (lasers)

  9. Pulsed electric fields

    The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

  10. A fitted formula for calculation of three-section solenoids inductance%一种多层螺线管电感计算拟合公式

    巨金川; 武大鹏; 舒挺

    2016-01-01

    提出了一种多层螺线管线圈电感的精确计算方法,其思想是叠加螺线管单层线圈的自感和不同线圈层之间的互感。建立了用于计算单层线圈自感的显示表达理论模型,给出了两层线圈之间互感的数值计算方法。使用提出的精确算法,计算出一个实验中使用的螺线管线圈的电感为4.30 mH,与实验测量的电感值4.33 mH 的偏差小于1%。%An algorithm for precisely calculating the inductance of a three-section solenoid is presented, which is based on summing the layer self-inductances and the mutual inductances.A theoretical model with ex-plicit expressions is firstly developed to calculate the self-inductance of a single layer,and then numerical calcu-lation of the mutual inductance between two layers is introduced.Using the presented computation method,the inductance of a solenoid designed in the experiment is successfully calculated (4.30 mH),which has a difference of less than 1% from the experimental data.

  11. A combined solenoid-surface RF coil for high-resolution whole-brain rat imaging on a 3.0 Tesla clinical MR scanner.

    Underhill, Hunter R; Yuan, Chun; Hayes, Cecil E

    2010-09-01

    Rat brain models effectively simulate a multitude of human neurological disorders. Improvements in coil design have facilitated the wider utilization of rat brain models by enabling the utilization of clinical MR scanners for image acquisition. In this study, a novel coil design, subsequently referred to as the rat brain coil, is described that exploits and combines the strengths of both solenoids and surface coils into a simple, multichannel, receive-only coil dedicated to whole-brain rat imaging on a 3.0 T clinical MR scanner. Compared with a multiturn solenoid mouse body coil, a 3-cm surface coil, a modified Helmholtz coil, and a phased-array surface coil, the rat brain coil improved signal-to-noise ratio by approximately 72, 61, 78, and 242%, respectively. Effects of the rat brain coil on amplitudes of static field and radiofrequency field uniformity were similar to each of the other coils. In vivo, whole-brain images of an adult male rat were acquired with a T(2)-weighted spin-echo sequence using an isotropic acquisition resolution of 0.25 x 0.25 x 0.25 mm(3) in 60.6 min. Multiplanar images of the in vivo rat brain with identification of anatomic structures are presented. Improvement in signal-to-noise ratio afforded by the rat brain coil may broaden experiments that utilize clinical MR scanners for in vivo image acquisition.

  12. 基于ANSYS的电子提花机电磁阀性能研究%Study on Performance of Electronic Jacquard Solenoid Valve Based on ANSYS

    杨霞

    2014-01-01

    This paper is purposed through establishing the electromagnetic analysis model based on ANSYS solenoid valve module to obtain the magnetic line of force, flux density, electromagnetic strength and electromagnetic force analyze the binary relation between electromagnetic force and voltage under the stable state, and get the relational expression of F/U through MATLAB, so as to optimum design the driving voltage and to optimum design the structure parameters of solenoid valve, such as shape of electromagnet, turns, suction area, magnetic material, reset spring, etc.%通过建立基于ANSYS电磁阀组件的电磁分析模型,得到其磁力线、磁通密度、电磁强度、电磁力,分析稳态状态下电磁力与电压的二次关系,并通过MATLAB建立F/U的拟合关系式,从而对驱动电压进行优化设计,并可对电磁阀组件的结构参数如电磁铁形状、线圈匝数、吸合面积、磁性材料、复位弹簧参数等进行优化设计。

  13. An improved billet on billet extrusion process of continuous aluminium alloy shapes for cryogenic applications in the Compact Muon Solenoid experiment

    Tavares, S S

    2003-01-01

    The Compact Muon Solenoid (CMS) is one of the experiments being designed in the framework of the Large Hadron Collider accelerator at CERN. CMS will contain the largest and the most powerful superconducting solenoid magnet ever built in terms of stored energy. It will work at 4.2 K, will have a magnetic length of 12.5 m, with a free bore of 6m and will be manufactured as a layered and modular structure of NbTi cables embedded in a high purity (99.998%) Al- stabiliser. Each layer consists of a wound continuous length of 2.55 km. In order to withstand the high electromagnetic forces, two external aluminium alloy reinforcing sections are foreseen. These reinforcements, of 24 mm multiplied by 18 mm cross-section, will be continuously electron beam (EB) welded to the pure Al-stabiliser. The alloy EN AW-6082 has been selected for the reinforcements due to its excellent extrudability, high strength in the precipitation hardened state, high toughness and strength at cryogenic temperatures and ready EB weldability. Ea...

  14. Characterization of Nyquist ghost in EPI-fMRI acquisition sequences implemented on two clinical 1.5 T MR scanner systems: effect of readout bandwidth and echo spacing.

    Giannelli, Marco; Diciotti, Stefano; Tessa, Carlo; Mascalchi, Mario

    2010-07-12

    In EPI-fMRI acquisitions, various readout bandwidth (BW) values are used as a function of gradients' characteristics of the MR scanner system. Echo spacing (ES) is another fundamental parameter of EPI-fMRI sequences, but the employed ES value is not usually reported in fMRI studies. Nyquist ghost is a typical EPI artifact that can degrade the overall quality of fMRI time series. In this work, the authors assessed the basic effect of BW and ES for two clinical 1.5 T MR scanner systems (scanner-A, scanner-B) on Nyquist ghost of gradient-echo EPI-fMRI sequences. BW range was: scanner-A, 1953-3906 Hz/pixel; scanner-B, 1220-2894 Hz/pixel. ES range was: scanner-A, scanner-B: 0.75-1.33 ms. The ghost-to-signal ratio of time series acquisition (GSRts) and drift of ghost-to-signal ratio (DRGSR) were measured in a water phantom. For both scanner-A (93% of variation) and scanner-B (102% of variation) the mean GSRts significantly increased with increasing BW. GSRts values of scanner-A did not significantly depended on ES. On the other hand, GSRts values of scanner-B significantly varied with ES, showing a downward trend (81% of variation) with increasing ES. In addition, a GSRts spike point at ES = 1.05 ms indicating a potential resonant effect was revealed. For both scanners, no significant effect of ES on DRGSR was revealed. DRGSR values of scanner-B did not significantly vary with BW, whereas DRGSR values of scanner-A significantly depended on BW showing an upward trend from negative to positive values with increasing BW. GSRts and DRGSR can significantly vary with BW and ES, and the specific pattern of variation may depend on gradients performances, EPI sequence calibrations and functional design of radiofrequency coil. Thus, each MR scanner system should be separately characterized. In general, the employment of low BW values seems to reduce the intensity and temporal variation of Nyquist ghost in EPI-fMRI time series. On the other hand, the use of minimum ES value might not be entirely advantageous when the MR scanner is characterized by gradients with low performances and suboptimal EPI sequence calibration.

  15. Detection and appearance of intraparenchymal haematomas of the brain at 1.5 T with spin-echo, FLAIR and GE sequences: poor relationship to the age of the haematoma

    Alemany Ripoll, M. [Department of Radiology, Uppsala University Hospital, Uppsala (Sweden); Fundacion Rioja Salud, Avda de Portugal no. 7, Logrono, La Rioja (Spain); Stenborg, A.; Terent, A. [Department of Internal Medicine, Uppsala University Hospital, Uppsala (Sweden); Sonninen, P. [Department of Radiology, Turku University Hospital, Turku (Finland); Raininko, R. [Department of Radiology, Uppsala University Hospital, Uppsala (Sweden)

    2004-06-01

    The specific appearance of blood related to time at T1- and T2-weighted spin-echo (SE) sequences is generally accepted; thus, these sequences are classically used for estimating the age of haematomas. Magnetic resonance imaging at 1.5 T, including T1- and T2-weighted SE fluid-attenuated inversion recovery (FLAIR) and T2*-weighted gradient-echo (GE) sequences, was performed on 82 intraparenchymal haematomas (IPHs) and 15 haemorrhagic infarcts (HIs) in order to analyse the appearance at different stages and with different sequences, and to investigate how reliably the age of hematomas can be estimated. The IPHs had been previously detected by CT, were spontaneous (n=72) or traumatic (n=10) in origin and were of different sizes (2 mm to 7 cm) and ages (from 7.5 h to 4 years after acute haemorrhagic event). The age of the lesion was calculated from the moment when clinical symptoms started or the traumatic event occurred. The 15 patients with HIs were patients with ischaemic stroke in whom there was either a suspicion of haemorrhagic transformation on CT, or haemorrhage was detected as an additional finding on MR performed for other indications. Patients with conditions that could affect the SI of blood, such as anticoagulant therapy or severe anaemia, were excluded. The signal intensity pattern of the lesions was analysed and related to their ages without prior knowledge of the clinical data. All lesions were detected with T2*-weighted GE. T1-weighted SE missed 13 haematomas and T2-weighted SE and FLAIR sequences missed five. Haemorrhagic transformation was missed in three infarcts by T1-, T2-weighted SE and FLAIR. The signal pattern on FLAIR was identical to that on T2-weighted SE. For all sequences, a wide variety of signal patterns, without a clear relationship to the age of the haematomas, was observed. There was a poor relationship between the real MR appearance of IPHs and the theoretical appearance on SE sequences. T2*-weighted GE was effective for detecting small bleedings but was not useful for estimating the age of a lesion. The FLAIR does not provide any more information than T2-weighted SE. (orig.)

  16. 一种用于自动变速器的比例电磁阀研究%Research on Proportional Solenoid Valve Used for Automatic Transmission

    孟飞; 陶刚; 陈慧岩

    2014-01-01

    介绍一种用于自动变速器的比例电磁阀结构,研究比例电磁阀的分析、设计方法及其稳态和动态特性。在结构分析的基础上,分析其工作原理,将比例电磁阀分为电场、磁场、机械和流体四部分,分析这四部分的内在耦合关系。建立各个部分的动态特性数学模型并进行耦合仿真分析,对比例电磁阀电磁特性进行研究,通过与试验结果对比,初步验证耦合仿真模型的正确性。通过计算分析电磁阀内部参量的动态变化特性,为优化电磁阀设计奠定基础。在液压部分中,进油口采用球阀,排油口采用喷嘴挡板阀,通过控制排油口的开度可以进行流量控制,间接控制油压输出。在比例电磁阀开启时,电磁力与弹簧力的总和与球阀的液压力相平衡的工作模式,使该比例电磁阀具有开关响应快、输入电流与输出油压线性关系好的特点。研究结果表明,该比例电磁阀阀芯位移0.2 mm ,开启响应时间在2 ms以内,油压建立在4 ms以内,适用于自动变速器换挡执行回路中。%The structure of a proportional solenoid valve for automatic transmission is introduced. The design, analysis methodology and dynamic performances of the valve are discussed. Based on the structural analysis of the valve, the operating principle is investigated. Four subsystems that are electric field, magnetic field, mechanical, and hydraulic of the proportional solenoid valve are divided, and their inherent coupling interactions are investigated. The mathematical model of the dynamic performance of the four subsystems is built separately and simulation analysis is carried out. The active process of the proportional solenoid valve is studied by combining with experimental results, verified the correctness of the coupling simulation model. It would be useful for proportional solenoid valve optimal design by analyzing the internal parameters dynamic

  17. Sequentially pulsed traveling wave accelerator

    Caporaso, George J.; Nelson, Scott D.; Poole, Brian R.

    2009-08-18

    A sequentially pulsed traveling wave compact accelerator having two or more pulse forming lines each with a switch for producing a short acceleration pulse along a short length of a beam tube, and a trigger mechanism for sequentially triggering the switches so that a traveling axial electric field is produced along the beam tube in synchronism with an axially traversing pulsed beam of charged particles to serially impart energy to the particle beam.

  18. A THERMAL PULSE SHAPER MECHANISM.

    A shaped pulse of intense thermal radiation, corresponding to the pulses from nuclear weapons, is obtained by the output of a QM carbon arc. A flywheel driven by a DC motor actuated a venetian blind shutter placed between a mirror and the target to control the flux. The combination produced reasonably good simulation and reproduction of the generalized field pulse.

  19. Noisy homoclinic pulse dynamics

    Eaves, T. S.; Balmforth, Neil J.

    2016-04-01

    The effect of stochastic perturbations on nearly homoclinic pulse trains is considered for three model systems: a Duffing oscillator, the Lorenz-like Shimizu-Morioka model, and a co-dimension-three normal form. Using the Duffing model as an example, it is demonstrated that the main effect of noise does not originate from the neighbourhood of the fixed point, as is commonly assumed, but due to the perturbation of the trajectory outside that region. Singular perturbation theory is used to quantify this noise effect and is applied to construct maps of pulse spacing for the Shimizu-Morioka and normal form models. The dynamics of these stochastic maps is then explored to examine how noise influences the sequence of bifurcations that take place adjacent to homoclinic connections in Lorenz-like and Shilnikov-type flows.

  20. Computationally intelligent pulsed photoacoustics

    Lukić, Mladena; Ćojbašić, Žarko; Rabasović, Mihailo D.; Markushev, Dragan D.

    2014-12-01

    In this paper, the application of computational intelligence in pulsed photoacoustics is discussed. Feedforward multilayer perception networks are applied for real-time simultaneous determination of the laser beam spatial profile and vibrational-to-translational relaxation time of the polyatomic molecules in gases. Networks are trained and tested with theoretical data adjusted for a given experimental set-up. Genetic optimization has been used for calculation of the same parameters, fitting the photoacoustic signals with a different number of generations. Observed benefits from the application of computational intelligence in pulsed photoacoustics and advantages over previously developed methods are discussed, such as real-time operation, high precision and the possibility of finding solutions in a wide range of parameters, similar to in experimental conditions. In addition, the applicability for practical uses, such as the real-time in situ measurements of atmospheric pollutants, along with possible further developments of obtained results, is argued.

  1. Magnetic Pulse Welding Technology

    Ahmad K. Jassim

    2011-12-01

    Full Text Available In this paper, the benefits of using Magnetic Pulse machine which is belong to Non-conventional machine instead of conventional machine. Magnetic Pulse Technology is used for joining dissimilar metals, and for forming and cutting metals. It is a non contact technique. Magnetic field is used to generate impact magnetic pressure for welding and forming the work piece by converted the electrical energy to mechanical energy. It is enable us to design previously not possible by welding dissimilar materials and allowing to welds light and stronger materials together. It can be used to weld metallic with non metallic materials to created mechanical lock on ceramics, polymers, rubbers and composites. It is green process; there is no heat, no radiation, no gas, no smoke and sparks, therefore the emissions are negligible.

  2. Measurement of pulse lengthening with pulse energy increase in picosecond Nd:YAG laser pulses

    Cutolo, A.; Zeni, L.; Berardi, V.; Bruzzese, R.; Solimeno, S.; Spinelli, N.

    1989-03-15

    Taking advantage of a new technique, we have monitored the relative variations of time duration and mode size as a function of the pulse energy for 30-ps-long Nd:YAG laser pulses. In particular, by carrying out a statistical analysis, we have observed that the pulse time duration is an increasing function of the pulse energy, according to the theoretical modeling of passively mode-locked lasers. The measurements can be easily extended to the femtosecond regime.

  3. Ptychographic ultrafast pulse reconstruction

    Spangenberg, D; Brügmann, M H; Feurer, T

    2014-01-01

    We demonstrate a new ultrafast pulse reconstruction modality which is somewhat reminiscent of frequency resolved optical gating but uses a modified setup and a conceptually different reconstruction algorithm that is derived from ptychography. Even though it is a second order correlation scheme it shows no time ambiguity. Moreover, the number of spectra to record is considerably smaller than in most other related schemes which, together with a robust algorithm, leads to extremely fast convergence of the reconstruction.

  4. STUCTURE OF PULSED BED

    I. A. Bokun

    2014-01-01

    Full Text Available The structure of pulsed layer is proposed which can be suggested as a state of particulates that is blown by intermittent gas flow with speed which has the force to start material moving. Layer during one cycle is in a suspension, falling down and immobile state resulting in changes of particles arrangement as well as ways of gas flowing through layer. Moreover, it allows carrying out effective interphase heat exchange even adamant real granulation.The process of formation of impact flows is considered aw well as their influence on formation of air bubbles in pulsed layer. At startup of air blast the balance between the force of hydro-dynamic resistance is broken, on one side, and forces of gravity, particles inertia and their links with walls on the other side. The layer is transferred in the state of pulsed pseudo-fluidization, and presents gas-disperse mixture, inside of which impulse of pressure increasing is spreading to all sides as pressure waves (compression. These waves are the sources of impact flows’ formation, the force of which is two times more than during the stationary flow.The waves of pressure are divided into weak and strong ones depending on movement velocity within gas-disperse system. Weak waves are moving with a sound speed and strong ones in active phase of pulsed layer are moving over the speed of sound limit within gas-disperse system. The peculiarity of strong wave is that parameters of system (pressure, density and others are changing in discrete steps.The article describes the regime of layer’s falling down in the passive stage of cycle, which begins after finishing of gas impulse action. And suspension layer of moving up granular material is transferred in the state of falling resulting in change of the layer structure.

  5. PULSE Pilot Certification Results

    Pamela Pape-Lindstrom

    2015-08-01

    Full Text Available The pilot certification process is an ambitious, nationwide endeavor designed to motivate important changes in life sciences education that are in line with the recommendations of the 2011 Vision and Change Report: A Call to Action (American Association for the Advancement of Science [AAAS], 2011.  It is the goal of the certification process to acknowledge departments that have progressed towards full implementation of the tenets of Vision and Change and to motivate departments that have not begun to adopt the recommendations to consider doing so.  More than 70 life science departments applied to be part of the pilot certification process, funded by a National Science Foundation grant, and eight were selected based on initial evidence of transformed and innovative educational practices.  The programs chosen represent a wide variety of schools, including two-year colleges, liberal-arts institutions, regional comprehensive colleges, research universities and minority serving institutions.  Outcomes from this pilot were released June 1, 2015 (www.pulsecommunity.org, with all eight programs being recognized as having progressed along a continuum of change.  Five levels of achievement were defined as PULSE Pilot Progression Levels.  Of the eight departments in the pilot, one achieved “PULSE Progression Level III: Accomplished”.  Six departments achieved “PULSE Progression Level II: Developing” and one pilot department achieved “PULSE Progression Level I: Beginning”.  All of the schools have made significant movement towards the recommendations of Vision and Change relative to a traditional life sciences curriculum.  Overall, the response from the eight pilot schools has been positive. 

  6. Twitter's visual pulse

    Hare, Jonathon; Samangooei, Sina; Dupplaw, David; Lewis, Paul H.

    2013-01-01

    Millions of images are tweeted every day, yet very little research has looked at the non-textual aspect of social media communication. In this work we have developed a system to analyse streams of image data. In particular we explore trends in similar, related, evolving or even duplicated visual artefacts in the mass of tweeted image data — in short, we explore the visual pulse of Twitter.

  7. Downhole pulse radar

    Chang, Hsi-Tien

    1987-09-28

    A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

  8. Pulse Portraiture: Pulsar timing

    Pennucci, Timothy T.; Demorest, Paul B.; Ransom, Scott M.

    2016-06-01

    Pulse Portraiture is a wideband pulsar timing code written in python. It uses an extension of the FFTFIT algorithm (Taylor 1992) to simultaneously measure a phase (TOA) and dispersion measure (DM). The code includes a Gaussian-component-based portrait modeling routine. The code uses the python interface to the pulsar data analysis package PSRCHIVE (ascl:1105.014) and also requires the non-linear least-squares minimization package lmfit (ascl:1606.014).

  9. Pulse Distributing Manifold; Pulse Distributing Manifold

    Schutting, Eberhard [Technische Univ. Graz (Austria); Sams, Theodor [AVL List GmbH, Graz (Austria); Glensvig, Michael [Forschungsgesellschaft mbH, Graz (AT). Kompetenzzentrum ' ' Das virtuelle Fahrzeug' ' (VIF)

    2011-07-01

    The Pulse Distributing Manifold is a new charge exchange method for turbocharged diesel engines with exhaust gas recirculation (EGR). The method is characterized in that the EGR mass flow is not diverted from the exhaust gas mass flow continuously, but over time broken into sub-streams. The temporal interruption is achieved by two phase-shifted outlet valves which are connected via separate manifolds only with the turbocharger or only with the EGR path. The time points of valve opening are chosen such that the turbocharger and the aftertreatment process of exhaust gas is perfused by high-energy exhaust gas of the blowdown phase while cooler and less energy-rich exhaust gas of the exhaust period is used for the exhaust gas recirculation. This increases the enthalpy for the turbocharger and the temperature for the exhaust gas treatment, while the cooling efficiency at the EGR cooler is reduced. The elimination of the continuous EGR valve has a positive effect on pumping losses. The principle functioning and the potential of this system could be demonstrated by means of a concept study using one-dimensional simulations. Without disadvantages in fuel consumption for the considered commercial vehicle engine, a reduction the EGR cooler performance by 15 % and an increase in exhaust temperature of 35 K could be achieved. The presented charge exchange method was developed, evaluated and patented within the scope of the research program 'K2-mobility' of the project partners AVL (Mainz, Federal Republic of Germany) and University of Technology Graz (Austria). The research project 'K2-Mobility' is supported by the competence center 'The virtual vehicle' Forschungsgesellschaft mbH (Graz, Austria).

  10. High-speed pulse-shape generator, pulse multiplexer

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  11. 车用电磁阀故障诊断一般方法的研究%A Research on a General Method of Fault Diagnosis for Vehicle's Solenoid Valve

    密刚刚; 周文华; 沈成宇

    2012-01-01

    分析了车用电喷发动机常用电磁阀的驱动特性,提出了电磁阀相关故障检测的一般方法.通过故障检测硬件电路设计和利用模糊层次分析方法设计相关诊断软件,在柴油机高压油泵电磁阀上进行了实际的故障诊断试验.结果表明,该诊断方法很好地实现了对电磁阀的断路和对地、对电源及内部短路等故障的诊断,达到了系统应用的要求.%The driving characteristics of solenoid valve commonly used in electrically controlled fuel injection engine of vehicles are analyzed and a general method of fault diagnosis for solenoid valve is proposed. Based on the designs of hardware circuit for fault detection and corresponding software for fault diagnosis by using fuzzy AHP technique, a real fault diagnosis test is performed on the solenoid valve of the high pressure fuel pump in a diesel engine. The results show that the diagnosis method can well fulfill the diagnosis on the faults of circuit break, short circuit to ground, short circuit to source and inner short circuit of solenoid valve, meeting the requirements of system application.

  12. 电控高压共轨柴油机电磁阀驱动电路分析与实验%Analysis of and Experiments on the Solenoid Drive Circuit of the High-Pressure Common Rail Diesel Engine

    张亚平

    2012-01-01

    With a certain type of the BOSCH injector as the object of our studies,a solenoid drive circuit of the high-pressure common rail diesel engine is designed and simulated in the paper,with all the relevant experiments carried out.The experimental results show that the designed solenoid drive circuit can meet the requirements in the quick response of the solenoid,with its good dynamic performance achieved.In the meanwhile,the power consumption of the solenoid drive is reduced.%以BOSCH某型喷油器为研究对象,对电控高压共轨柴油机电磁阀驱动电路进行了硬件电路设计和仿真分析,并完成了相关实验。实验结果证明设计的电磁阀驱动电路可以达到喷油器电磁阀的快速响应要求、动态特性良好,从而在提高电磁阀快速开启响应能力的同时达到了降低电磁阀驱动功耗的目的。

  13. Magnetic Circuit Structure Optimization Design for Injection Solenoid Valve Based on Ansoft%基于Ansoft的喷油电磁阀磁路结构优化设计

    焦禹; 刘京; 庞宝麟; 蔡胜年

    2013-01-01

    To realize the requirements of high speed response for injection solenoid valve in diesel engine common rail type injec-tion system,injection solenoid valve 2D model was established using Ansoft finite element analysis soft.The main factors affecting re-sponse of the injection solenoid valve were simulated and analyzed from structure.The simulation results show that using the optimiza-tion structure,the injection solenoid valve fast response velocity is increased 65.4%.%为实现柴油机共轨式喷油系统中的喷油电磁阀的高速响应要求,利用Ansoft有限元分析软件建立喷油电磁阀的二维模型,从电磁阀的结构出发,对影响喷油电磁阀响应的主要因素进行了静、动态仿真分析,得到了优化后的喷油电磁阀结构。仿真计算结果表明,采用优化后的结构,柴油机喷油电磁阀的快速响应性提高了65.4%。

  14. Modeling and Dynamic Response Characteristics Analysis of High-Speed Solenoid Valve Based on Test Data%基于试验数据的高速电磁阀建模及动态响应特性分析

    李汝宁; 高怡; 吕帆; 李华乐; 徐春龙; 赵中余

    2016-01-01

    高速电磁阀的响应特性对高压共轨喷油器的喷油特性具有决定性影响。为了更合理和准确地预测高速电磁阀的电磁特性,基于高速电磁阀理论分析,进行了大量不同驱动电流强度和气隙情况下的电磁力试验,采用多项式拟合的方法,对试验数据进行拟合,结合高速电磁阀的工作原理,应用Amesim软件建立高速电磁阀一维仿真模型,并研究分析了驱动电流、阀芯弹簧预紧力和刚度对高速电磁阀动态响应特性的影响。研究结果表明:所采用的基于试验数据的高速电磁阀建模方式为其动态响应特性的研究提供了一个新思路,它能快速、准确得到高速电磁阀各参数对其响应特性的影响。%The dynamic response characteristics of high‐speed solenoid valve had a critical influence on injection characteristics of high‐pressure common‐rail injector .In order to predict the electromagnetic characteristics of high‐speed solenoid valve more accurately ,a great deal of electromagnetic force tests under the conditions of different current intensities and air gaps were car‐ried out based on theoretical analysis of high‐speed solenoid valve ,the test data were fitted with the polynomial fitting method , and finally one‐dimensional simulation model of high‐speed solenoid valve was built with AMEsim software according to the working principles of high‐speed solenoid valve .Then the influences of three parameters such as drive current ,preload and elas‐tic strength of valve element spring on the dynamic response characteristics of high‐speed solenoid valve were studied .The re‐sults show that the modeling method based on test data offers a new idea to study the dynamic response characteristics of high‐speed solenoid valve ,w hich can acquire the influences of each parameter on the dynamic response characteristics fast and accu‐rately .

  15. Design and Experimental Research of the Linear Bi-directional Force Solenoid for Electro-hydraulic Proportional Valve%比例阀线性双向电磁铁设计与试验研究

    吴帅; 彭传龙; 焦宗夏; 王晓东; 王晓腾; 彭刚

    2014-01-01

    Proportional solenoid is the driving devices electromagnetic to control the action of the proportional valve. The overall performance of the proportional solenoid is largely determined by this part. The traditional solenoids have the following disadvantages. The linearity of the solenoid is poor. The effective stroke is short. And the barrier magnetic is installed difficulty. In view of the above the shortcomings, a new structure of the linear force solenoid is presented. The composite magnetic force generated by the permanent magnets and electromagnetic field is using to drive the armature. The barrier magnetic in the new solenoid is canceled, so the solenoid can assemble easily. Theoretical analysis and finite element simulation is done for its design optimization in this paper. One prototype is designed and manufactured, and the designed structure is verified by experiment.%比例电磁铁是控制比例阀先导级阀芯动作的电磁驱动元件,其性能在很大程度上决定比例阀的整体性能。针对传统比例电磁铁线性度差、比例范围短、隔磁环安装困难等不足,设计一种新型结构的比例电磁铁,这种比例电磁铁采用永磁体与线圈产生的复合磁场力驱动衔铁运动,同时新型结构的比例电磁铁中取消传统比例电磁铁的隔磁环结构,降低加工难度并且具有较传统的比例电磁铁更好的性能。对设计的新型电磁铁进行数学建模和理论分析验证其理论的可行性,并且对同等尺寸的比例电磁铁进行仿真优化设计,获得尺寸条件限制下的性能最佳的比例电磁铁设计。在理论分析的基础上,通过对样机的电磁力测试获得的试验数据与理论分析数据一致,验证了这种新型结构的比例电磁铁的实用性。

  16. The Evolution of the Control System for the Electromagnetic Calorimeter of the Compact Muon Solenoid Experiment at the Large Hadron Collider

    Holme, Oliver; Dissertori, Günther; Lustermann, Werner; Zelepoukine, Serguei

    2011-01-01

    This paper discusses the evolution of the Detector Control System (DCS) designed and implemented for the Electromagnetic Calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) as well as the operational experience acquired during the LHC physics data taking periods of 2010 and 2011. The current implementation in terms of functionality and planned hardware upgrades are presented. Furthermore, a project for reducing the long-term software maintenance, including a year-long detailed analysis of the existing applications, is put forward and the current outcomes which have informed the design decisions for the next CMS ECAL DCS software generation are described. The main goals for the new version are to minimize external dependencies enabling smooth migration to new hardware and software platforms and to maintain the existing functionality whilst substantially reducing support and maintenance effort through homogenization, simplification and standardization of the contr...

  17. 高速电磁阀模糊PID测控系统的设计%Design on Fuzzy-PID Control System of High-speed Solenoid

    蒲亮亮; 张小栋

    2009-01-01

    For the problem of poor control precision of high-speed solenoid valves which are widely used in aero-engine control systems,a fuzzy-PID control system based on Soc single-chip is designed in this paper by using fuzzy self-tuning of PID parameters control algorithm.%针对航空发动机控制系统中高速电磁阀存在控制精度差的问题,采用PID参数模糊自整定的控制算法,设计了基于Soc单片机的高速电磁阀模糊PID测控系统.

  18. 增压发动机中电磁阀的研究和应用%Study and Application of Solenoid Valve in Turbocharged Engine

    王欣

    2015-01-01

    From the turbocharged engine "on / off" electromagnetic valve and a PWM solenoid valve principle and functions of the, electromagnetic valve are studied in the turbocharged engine of loop control the intake and exhaust pressure regulation and its layout forms by the intake cycle control arrangement of comparing the advantages and disadvantages,for the pressurization system arrangement to provide for design and development.%从增压发动机“开/关”电磁阀和PWM电磁阀的原理及功能出发,研究电磁阀在增压发动机中对进气循环控制、排气压力调节的作用及其布置形式,通过对进气循环控制的布置优缺点对比,为增压系统布置提供设计开发依据。

  19. Sources of Emittance in RF Photocathode Injectors: Intrinsic emittance, space charge forces due to non-uniformities, RF and solenoid effects

    Dowell, David H

    2016-01-01

    Advances in electron beam technology have made possible the current generation of x-ray free electron lasers and electron microscopes. These devices have become valuable tools for basic research and applied science. An important technology related to xfels is the photocathode RF gun and injector. The invention of the RF gun and the developments of emittance compensation and beam matching were driving forces behind these new technologies. Achieving even brighter beams requires taking a finer resolution view of the electron dynamics near the cathode during emission and initial acceleration. In addition the bright beam is sensitive to optical aberrations in the injector's RF and magnetic lenses. This paper discusses these topics including beam properties due to cathode material properties, space charge effects close to the cathode and optical distortions of the RF and solenoid fields. Analytic relations for these phenomena are derived and compared with numerical simulations.

  20. Effects of SF$_{6}$ on the avalanche mode operation of a real-sized double-gap resistive plate chamber for the Compact Muon Solenoid experiment

    Ahn Sung Hwan; Hong, B; Hong, S J; Ito, M; Kim, B I; Kim, J H; Kim, Y J; Kim, Y U; Koo, D G; Lee, H W; Lee, K B; Lee, K S; Lee, S J; Lim, J K; Moon, D H; Nam, S K; Park, S; Park, W J; Rhee, J T; Ryu, M S; Shim, H H; Sim, K S; Kang, T I

    2005-01-01

    We present the design and the test, results for a real-sized prototype resistive plate chamber by using cosmic-ray muons for the forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). In particular, we investigate the effects of adding SF/sub 6/ to the gas mixture for the avalanche mode operation of a resistive plate chamber. A small fraction of SF/sub 6/ is very effective in suppressing streamer signals in a resistive plate chamber. The shapes of the muon detection efficiency and the muon cluster size remain similar, but are shifted to higher operating voltage by SF/sub 6/. The noise cluster rate and size are not influenced by SF/sub 6/.

  1. Coiled transmission line pulse generators

    McDonald, Kenneth Fox (Columbia, MO)

    2010-11-09

    Methods and apparatus are provided for fabricating and constructing solid dielectric "Coiled Transmission Line" pulse generators in radial or axial coiled geometries. The pour and cure fabrication process enables a wide variety of geometries and form factors. The volume between the conductors is filled with liquid blends of monomers, polymers, oligomers, and/or cross-linkers and dielectric powders; and then cured to form high field strength and high dielectric constant solid dielectric transmission lines that intrinsically produce ideal rectangular high voltage pulses when charged and switched into matched impedance loads. Voltage levels may be increased by Marx and/or Blumlein principles incorporating spark gap or, preferentially, solid state switches (such as optically triggered thyristors) which produce reliable, high repetition rate operation. Moreover, these Marxed pulse generators can be DC charged and do not require additional pulse forming circuitry, pulse forming lines, transformers, or an a high voltage spark gap output switch. The apparatus accommodates a wide range of voltages, impedances, pulse durations, pulse repetition rates, and duty cycles. The resulting mobile or flight platform friendly cylindrical geometric configuration is much more compact, light-weight, and robust than conventional linear geometries, or pulse generators constructed from conventional components. Installing additional circuitry may accommodate optional pulse shape improvements. The Coiled Transmission Lines can also be connected in parallel to decrease the impedance, or in series to increase the pulse length.

  2. Magnetic axis control techniques of large size solenoid%大尺寸螺线管线圈的磁轴控制技术

    代志勇; 廖树清; 刘云龙; 谢宇彤; 王永伟; 臧宗旸; 肖贝禾

    2013-01-01

    从匀场环结构参数优化设计、线圈线包材料规格的选择、绕制工艺探索、超大幅面二极校正线圈研制、全新准直方法的磁轴检测技术等多方面研究大尺寸螺线管线圈的磁轴控制技术.突破了磁轴倾斜小于等于1 mrad的技术指标,成功研制出磁轴倾斜小于等于0.5 mrad的大尺寸聚焦线圈,解决了其中的关键单元部件研制的核心技术问题.%The magnetic-axis tilt,which is the most critical indicator of the focusing solenoid,is always the focus of researchers in related research fields.In this paper,many aspects,such as optimization of field-homogenizer design,the choice of material specifications,exploration of winding technology,design of super large size dipole steering coils,and magnetic-axis measurement technique are studied using new alignment method.The technical bottleneck of tilt less than 1.0 mrad is broken through and a large size focus solenoid whose magnetic-axis tilt is less than 0.5 mrad is successfully developed.

  3. Green Light Pulse Oximeter

    Scharf, John Edward (Oldsmar, FL)

    1998-11-03

    A reflectance pulse oximeter that determines oxygen saturation of hemoglobin using two sources of electromagnetic radiation in the green optical region, which provides the maximum reflectance pulsation spectrum. The use of green light allows placement of an oximetry probe at central body sites (e.g., wrist, thigh, abdomen, forehead, scalp, and back). Preferably, the two green light sources alternately emit light at 560 nm and 577 nm, respectively, which gives the biggest difference in hemoglobin extinction coefficients between deoxyhemoglobin, RHb, and oxyhemoglobin, HbO.sub.2.

  4. A Pulsed Sphere Tutorial

    Cullen, Dermott E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-01-30

    Here I attempt to explain what physically happens when we pulse an object with neutrons, specifically what we expect the time dependent behavior of the neutron population to look like. Emphasis is on the time dependent emission of both prompt and delayed neutrons. I also describe how the TART Monte Carlo transport code models this situation; see the appendix for a complete description of the model used by TART. I will also show that, as we expect, MCNP and MERCURY, produce similar results using the same delayed neutron model (again, see the appendix).

  5. Investigating the Inverse Faraday Effect with an intense short pulse laser

    Najmudin, Zulfikar; Tatarakis, Michealis; Krushelnick, Karl; Clark, Eugene; Santala, Marko; Dangor, Bucker; Clarke, Robert; Neely, David; Faure, Jerome; Malka, Victor

    2000-10-01

    A circularly polarised laser beam traversing through a plasma can generate an azimuthal electron current, due to their combined quiver motion. This will generate a solenoidal magnetic field in the plasma colinear with the laser propagation. This phenomena is known as the Inverse Faraday Effect (IFE), and can result in sizeable magnetic field strength for an ultra-intense laser pulses traversing through sufficiently dense plasmas. We present here measurements of the IFE field generated by the ultra-intense Vulcan:CPA laser travelling through underdense plasmas. The Vulcan:CPA laser can be focused to greater than 5 × 10^18 Wcm-2, and can generate IFE magnetic fields in excess of 2 MG. We present here the variation of the field with intensity and density, as well as measurements of its temporal and spatial behaviour. Noticeably the field is only observed for the time duration of the driver pulse, and decreases in spatial extent with increasing strength of magnetic field.

  6. COMPUTER BASED HEART PULSES MEASUREMENT

    Ali N. Hamoodi

    2013-05-01

    Full Text Available In this work the measurement and displays of blood oxygen saturation and pulse rate are investigated practically using computer.The analysis involves the variation in blood oxygen saturation ratio and pulse rate. The results obtained are compared with kontron pulse oximeter 7840 device. The value obtained for the same person pulse rate is approximately equal to that obtained by the konton pulse oximeter 7840 device. The sensor used in this work is the finger clip.The advantages of using computer over kontron pulse oximeter 7840 device is that the data of the patient can be saved in the computer for many years and also it can be display at any time so that the doctor get file contains all data for each patient. 

  7. Angular momentum of sound pulses.

    Lekner, John

    2006-07-05

    Three-dimensionally localized acoustic pulses in an isotropic fluid medium necessarily have transverse components of momentum density. Those with an azimuthal component of momentum density can carry angular momentum. The component of total pulse angular momentum along the direction of the total momentum is an invariant (constant in time and independent of choice of origin). The pulse energy, momentum and angular momentum are evaluated analytically for a family of localized solutions of the wave equation. In the limit where the pulses have many oscillations within their spatial extent ([Formula: see text], where k is the wavenumber and a determines the size of a pulse), the energy, momentum and angular momentum are consistent with a multiphonon representation of the pulse, each phonon having energy [Formula: see text], momentum [Formula: see text] and angular momentum [Formula: see text] (with integer m).

  8. Heat driven pulse pump

    Benner, Steve M (Inventor); Martins, Mario S. (Inventor)

    2000-01-01

    A heat driven pulse pump includes a chamber having an inlet port, an outlet port, two check valves, a wick, and a heater. The chamber may include a plurality of grooves inside wall of the chamber. When heated within the chamber, a liquid to be pumped vaporizes and creates pressure head that expels the liquid through the outlet port. As liquid separating means, the wick, disposed within the chamber, is to allow, when saturated with the liquid, the passage of only liquid being forced by the pressure head in the chamber, preventing the vapor from exiting from the chamber through the outlet port. A plurality of grooves along the inside surface wall of the chamber can sustain the liquid, which is amount enough to produce vapor for the pressure head in the chamber. With only two simple moving parts, two check valves, the heat driven pulse pump can effectively function over the long lifetimes without maintenance or replacement. For continuous flow of the liquid to be pumped a plurality of pumps may be connected in parallel.

  9. Bipolar pulse forming line

    Rhodes, Mark A.

    2008-10-21

    A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

  10. Multi pulse control of entanglement

    Uchiyama, C; Uchiyama, Chikako; Aihara, Masaki

    2004-01-01

    We study the effectiveness of multi pulse control to suppress the degradation of entanglement. Based on a linearly interacting spin-boson model, we show that the multi pulse application recovers the decay of concurrence when an entangled pair of spins interacts with a reservoir that has the non-Markovian nature. We present the effectiveness of multi pulse control for both the common bath case and the individual bath case.

  11. Assembly delay line pulse generators

    1971-01-01

    Assembly of six of the ten delay line pulse generators that will power the ten kicker magnet modules. One modulator part contains two pulse generators. Capacitors, inductances, and voltage dividers are in the oil tank on the left. Triggered high-pressure spark gap switches are on the platforms on the right. High voltage pulse cables to the kicker magnet emerge under the spark gaps. In the centre background are the assembled master gaps.

  12. Analysis of Pulse Modulated Control Systems (Ⅲ) Stability of Systems with Pulse Frequency Modulation and Systems with Combined Pulse Frequency and Pulse Width Modulation

    OI,Shigemitsu

    1993-01-01

    Sufficient conditions for finite pulse stability of interconnected systems with combined pulse frequency and pulse width modulation are developed in this paper using a direct method. The stability criteria established provide upper bounds on the number of pulses emitted by each modulator. The results are also applicable to those systems which contain a finite number of pulse frequency modulators and a finite number of combined pulse frequency and pulse width modulators

  13. Pulse oximetry in severe anaemia

    Ramsing, T; Rosenberg, J

    1992-01-01

    Measurement of arterial oxygen saturation by pulse oximetry was performed in two patients with acute and chronic anaemia (haemoglobin concentrations: 2.9 mmol/l (4.7 g/dl) and 1.9 mmol/l (3.0 g/dl), respectively) using a Radiometer OXI and a Nellcor N-200 pulse oximeter. The two oximeters read...... alternating different values in the two patients. In conclusion, pulse oximeters are able to give a value for oxygen saturation even at extreme anaemia, and when a high value is given, it possibly reflects arterial oxygen saturation. The value of pulse oximetry in severe anaemia is discussed....

  14. Population inversion by chirped pulses

    Lu Tianshi [Department of Mathematics and Statistics, Wichita State University, Wichita, Kansas 67260-0033 (United States)

    2011-09-15

    In this paper, we analyze the condition for complete population inversion by a chirped pulse over a finite duration. The nonadiabatic transition probability is mapped in the two-dimensional parameter space of coupling strength and detuning amplitude. Asymptotic forms of the probability are derived by the interference of nonadiabatic transitions for sinusoidal and triangular pulses. The qualitative difference between the maps for the two types of pulses is accounted for. The map is used for the design of stable inversion pulses under specific accuracy thresholds.

  15. Theoretical Studies of the Output Pulse with Variation of the Pumping Pulse for RF Excited CO2 Pulsed Waveguide Laser

    A Rauf; ZHOU Wei; XIN Jian-guo

    2006-01-01

    The behavior of a RF-excited waveguide CO2 laser in the pulse regime is studied theoretically. The output pulse evolution is studied by applying three types of pulses namely the square, sine and the triangular ones as the excitation pulses. The frequency dependence behavior of the output pulse is also presented.

  16. Temperature measurement on neurological pulse generators during MR scans

    Alesch François

    2002-09-01

    Full Text Available Abstract According to manufacturers of both magnetic resonance imaging (MRI machines, and implantable neurological pulse generators (IPGs, MRI is contraindicated for patients with IPGs. A major argument for this restriction is the risk to induce heat in the leads due to the electromagnetic field, which could be dangerous for the surrounding brain parenchyma. The temperature change on the surface of the case of an ITREL-III (Medtronic Inc., Minneapolis, MN and the lead tip during MRI was determined. An anatomical realistic and a cubic phantom, filled with phantom material mimicking human tissue, and a typical lead configuration were used to imitate a patient who carries an IPG for deep brain stimulation. The measurements were performed in a 1.5 T and a 3.0 T MRI. 2.1°C temperature increases at the lead tip uncovered the lead tip as the most critical part concerning heating problems in IPGs. Temperature increases in other locations were low compared to the one at the lead tip. The measured temperature increase of 2.1°C can not be considered as harmful to the patient. Comparison with the results of other studies revealed the avoidance of loops as a practical method to reduce heating during MRI procedures.

  17. Pulse-shaping strategies in short-pulse fiber amplifiers

    Schimpf, Damian Nikolaus

    2010-02-09

    Ultrashort pulse lasers are an important tool in scientific and industrial applications. However, many applications are demanding higher average powers from these ultrashort pulse sources. This can be achieved by combining direct diode pumping with novel gain media designs. In particular, ultrashort pulse fiber lasers are now delivering average powers in the kW range. However, the design of fiber lasers, producing pulses with high peak-powers, is challenging due to the impact of nonlinear effects. To significantly reduce these detrimental effects in ultrashort pulse fiber amplifers, the combination of chirped pulse amplification (CPA) and large mode area fibers is employed. Using these methods, the pulse energy of fiber lasers has been steadily increasing for the past few years. Recently, a fiber-based CPA-system has been demonstrated which produces pulse energies of around 1 mJ. However, both the stretching and the enlargement of the mode area are limited, and therefore, the impact of nonlinearity is still noticed in systems employing such devices. The aim of this thesis is the analysis of CPA-systems operated beyond the conventional nonlinear limit, which corresponds to accumulated nonlinear phase-shifts around 1 rad. This includes a detailed discussion of the influence of the nonlinear effect self-phase modulation on the output pulse of CPA-systems. An analytical model is presented. Emphasis is placed on the design of novel concepts to control the impact of self-phase modulation. Pulse-shaping is regarded as a powerful tool to accomplish this goal. Novel methods to control the impact of SPM are experimentally demonstrated. The design of these concepts is based on the theoretical findings. Both amplitude- and phase-shaping are studied. Model-based phase-shaping is implemented in a state-of-the-art fiber CPA-system. The influence of the polarization state is also highlighted. Additionally, existing techniques and recent advances are put into context. (orig.)

  18. Template Reproduction of GRB Pulse Light Curves

    Hakkila, Jon E.; Preece, R. D.; Loredo, T. J.; Wolpert, R. L.; Broadbent, M. E.

    2014-01-01

    A study of well-isolated pulses in gamma ray burst light curves indicates that simple models having smooth and monotonic pulse rises and decays are inadequate. Departures from the Norris et al. (2005) pulse shape are in the form of a wave-like pre-peak residual that is mirrored and stretched following the peak. Pulse shape departures are present in GRB pulses of all durations, but placement of the departures relative to pulse peaks correlates with asymmetry. This establishes an additional link between temporal structure and spectral evolution, as pulse asymmetry is related to initial hardness while pulse duration indicates the rate of hard-to-soft pulse evolution.

  19. Nanofabrication with pulsed lasers.

    Kabashin, Av; Delaporte, Ph; Pereira, A; Grojo, D; Torres, R; Sarnet, Th; Sentis, M

    2010-02-24

    An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  20. Pulsed plasma electron sourcesa)

    Krasik, Ya. E.; Yarmolich, D.; Gleizer, J. Z.; Vekselman, V.; Hadas, Y.; Gurovich, V. Tz.; Felsteiner, J.

    2009-05-01

    There is a continuous interest in research of electron sources which can be used for generation of uniform electron beams produced at E ≤105 V/cm and duration ≤10-5 s. In this review, several types of plasma electron sources will be considered, namely, passive (metal ceramic, velvet and carbon fiber with and without CsI coating, and multicapillary and multislot cathodes) and active (ferroelectric and hollow anodes) plasma sources. The operation of passive sources is governed by the formation of flashover plasma whose parameters depend on the amplitude and rise time of the accelerating electric field. In the case of ferroelectric and hollow-anode plasma sources the plasma parameters are controlled by the driving pulse and discharge current, respectively. Using different time- and space-resolved electrical, optical, spectroscopical, Thomson scattering and x-ray diagnostics, the parameters of the plasma and generated electron beam were characterized.

  1. Nanofabrication with Pulsed Lasers

    Kabashin AV

    2010-01-01

    Full Text Available Abstract An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3, is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser–matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  2. Nanosecond Pulse Technique

    1989-03-17

    tunnel diodes, to ferrites, etc.) and to the need for the review of the methods of formation and converting the pulses, to a considerable degree...4n3l) 0 1 + 4n 21)2 + (4n2l) (.84) _ 4 nf tl 5 (I - 4n12/) 2 - (4nil)’ (1.85) " ( - 2o) l - 4’n2% 2 I3 (I + 4n =2/)2 + ( 41a2 )’ -arg + 4ni,21. + j4na,tJ...recirculator is borrowed from the article of Yu. I. Neymark, Yu. K. Maklakov and L. P. Yelkins [105]. ENDFOOTNOTE. DOC = 88076720 PAGE d a) t l I t S6) t�t

  3. Pulsed plasma arc cladding

    龙; 白钢; 李振民; 张赋升; 杨思乾

    2004-01-01

    A prototype of Pulsed Plasma Arc Cladding system was developed, in which single power source supplies both transferred plasma arc (TPA) and non-transferred plasma arc (N-TPA). Both plasmas work in turn in a high frequency controlled by an IGBT connecting nozzle and workpiece. The working frequency of IGBT ranges from 50 ~ 7000Hz, in which the plasmas can work in turn smoothly. Higher than 500 Hz of working frequency is suggested for promotion of cladding quality and protection of IGBT. Drag phenomenon of TPA intensifies as the frequency goes up, which tends to increase the current proportion of TPA and suppress N-TPA. The occupation ratio of IGBT can be regulated from 5% ~ 95%, which balances the power supplies of both plasmas. An occupation ratio higher than 50% gives adequate proportion of arc current for N-TPA to preheat powder.

  4. Capacitor discharge pulse analysis.

    Baker, Michael Sean; Griffiths, Stewart K.; Tanner, Danelle Mary

    2013-08-01

    Capacitors used in firing sets and other high discharge current applications are discharge tested to verify performance of the capacitor against the application requirements. Parameters such as capacitance, inductance, rise time, pulse width, peak current and current reversal must be verified to ensure that the capacitor will meet the application needs. This report summarizes an analysis performed on the discharge current data to extract these parameters by fitting a second-order system model to the discharge data and using this fit to determine the resulting performance metrics. Details of the theory and implementation are presented. Using the best-fit second-order system model to extract these metrics results in less sensitivity to noise in the measured data and allows for direct extraction of the total series resistance, inductance, and capacitance.

  5. A scaling model for plasma columns produced by CO2 laser-induced breakdown in a solenoidal field

    Ahlborn, B.; Vlases, G. C.; Pietrzyk, Z. A.

    1982-12-01

    An analytical model is derived for the plasma cylinder produced by a long pulse (approximately microsec) CO2 laser of power p(l) (watts) which is incident upon neutral hydrogen imbedded in a strong axial magnetic field. Under certain conditions the leading edge of the plasma propagates away from the laser as an optical detonation, where the leading shock front fully ionizes the background gas, and the inverse bremsstrahlung absorption zone immediately behind it is equivalent to the chemical energy release zone in an ordinary detonation. The front velocity is V(od) = (3E(i)/m) to the 1/2 power, where E(i) is the ionization (and dissociation) energy. This velocity is in agreement with experiments and with certain stability considerations. Radial expansion takes place immediately behind the detonation front and reduces the density to about 1/3 of the initial filling gas density. Far behind the leading edge, the laser-produced plasma acquires an equilibrium radius and steady pressure, density, and temperature determined by a balance between laser energy absorption and conduction and radiation losses. The density profile maintains a shallow minimum on axis.

  6. Processing and characterization of superconducting solenoids made of Bi-2212/Ag-alloy multifilament round wire for high field magnet applications

    Chen, Peng

    As the only high temperature superconductor with round wire (RW) geometry, Bi2Sr2CaCu2O8+x (Bi-2212) superconducting wire has the advantages of being multi-filamentary, macroscopically isotropic and twistable. With overpressure (OP) processing techniques recently developed by our group at the National High Magnetic Field Laboratory (NHMFL), the engineering current density (Je) of Bi-2212 RW can be dramatically increased. For example, Je of more than 600 A/mm 2 (4.2 K and 20 T) is achieved after 100 bar OP processing. With these intrinsically beneficial properties and recent processing progress, Bi-2212 RW has become very attractive for high field magnet applications, especially for nuclear magnetic resonance (NMR) magnets and accelerator magnets etc. This thesis summarizes my graduate study on Bi-2212 solenoids for high field and high homogeneity NMR magnet applications, which mainly includes performance study of Bi-2212 RW insulations, 1 bar and OP processing study of Bi-2212 solenoids, and development of superconducting joints between Bi-2212 RW conductors. Electrical insulation is one of the key components of Bi-2212 coils to provide sufficient electrical standoff within coil winding pack. A TiO 2/polymer insulation offered by nGimat LLC was systematically investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurements, and transport critical current (Ic) property measurements. About 29% of the insulation by weight is polymer. When the Bi-2212 wire is fully heat treated, this decomposes with slow heating to 400 °C in flowing O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V. A Bi-2212 RW wound solenoid coil was built using this insulation being offered by nGimat LLC. The coil resistance was constant through coil winding, polymer burn

  7. Nonparametric estimation of ultrasound pulses

    Jensen, Jørgen Arendt; Leeman, Sidney

    1994-01-01

    An algorithm for nonparametric estimation of 1D ultrasound pulses in echo sequences from human tissues is derived. The technique is a variation of the homomorphic filtering technique using the real cepstrum, and the underlying basis of the method is explained. The algorithm exploits a priori...... liver from in vivo pulse-echo data. Estimates are given for 8 different patients...

  8. NMR in pulsed magnetic field

    Abou-Hamad, Edy

    2011-09-01

    Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.

  9. A Single-Pulse Integrator

    Miller, Arne

    1974-01-01

    A single-pulse integrator is described. It gives a relative measure of the integral of the output signal from a coil monitor on the Risø 10 MeV linear accelerator, and displays the value on a digital voltmeter. The reproduccibility is found to be better than ±1% for an accelerated pulse charge...

  10. Pulse oximetry for perioperative monitoring

    Pedersen, Tom; Møller, Ann Merete; Hovhannisyan, Karen

    2009-01-01

    Pulse oximetry is extensively used in the perioperative period and might improve patient outcomes by enabling an early diagnosis and, consequently, correction of perioperative events that might cause postoperative complications or even death. Only a few randomized clinical trials of pulse oximetry...

  11. Dexamethasone pulse therapy in pemphigus

    Toth, GG; van de Meer, JB; Jonkman, MF

    2002-01-01

    Pulse therapy with high-dose glucocorticoids was introduced 20 years ago as a treatment modality for autoimmune disease and transplant rejection. The most popular dermatological indication for pulse therapy is severe pemphigus. We reviewed the sequelae of 14 patients with pemphigus who were treated

  12. Pre-earthquake Magnetic Pulses

    Scoville, John; Freund, Friedemann

    2014-01-01

    A semiconductor model of rocks is shown to describe unipolar magnetic pulses, a phenomenon that has been observed prior to earthquakes. These pulses are observable because their extremely long wavelength allows them to pass through the Earth's crust. Interestingly, the source of these pulses may be triangulated to pinpoint locations where stress is building deep within the crust. We couple a semiconductor drift-diffusion model to a magnetic field in order to describe the electromagnetic effects associated with electrical currents flowing within rocks. The resulting system of equations is solved numerically and it is seen that a volume of rock may act as a diode that produces transient currents when it switches bias. These unidirectional currents are expected to produce transient unipolar magnetic pulses similar in form, amplitude, and duration to those observed before earthquakes, and this suggests that the pulses could be the result of geophysical semiconductor processes.

  13. Neurostimulation using subnanosecond electric pulses

    Xiao, Shu; Pakhomov, Andrei; Guo, Fei; Polisetty, Swetha; Schoenbach, Karl H.

    2013-02-01

    We have for the first time recorded action potentials in rat hippocampus neurons when they were stimulated by subnanosecond electric pulses. The preliminary results show that applying a series of pulses allowed the accumulation of depolarization before activating the voltage gated channels. The depolarization only occurred when the electric pulses were applied. It is unclear whether the depolarization is caused by the charge accumulation across the membrane or the cation influx due to the membrane permeabilization. We have also conducted an electromagnetic simulation of delivering subnanosecond pulses to tissues using an impulse radiating antenna. The results show that the pulses can be confined in the deep region in the brain but the amplitude is reduced significantly due to the attenuation of the tissues. A partially lossy dielectric lens may be used to reverse the decreasing trend of the electric field.

  14. Development of a Gas-Fed Pulse Detonation Research Engine

    Litchford, Ron J.; Hutt, John (Technical Monitor)

    2001-01-01

    In response to the growing need for empirical data on pulse detonation engine performance and operation, NASA Marshall Space Flight Center has developed and placed into operation a low-cost gas-fed pulse detonation research engine. The guiding design strategy was to achieve a simple and flexible research apparatus, which was inexpensive to build and operate. As such, the engine was designed to operate as a heat sink device, and testing was limited to burst-mode operation with run durations of a few seconds. Wherever possible, maximum use was made of standard off-the-shelf industrial or automotive components. The 5-cm diameter primary tube is about 90-cm long and has been outfitted with a multitude of sensor and optical ports. The primary tube is fed by a coaxial injector through an initiator tube, which is inserted directly into the injector head face. Four auxiliary coaxial injectors are also integrated into the injector head assembly. All propellant flow is controlled with industrial solenoid valves. An automotive electronic ignition system was adapted for use, and spark plugs are mounted in both tubes so that a variety of ignition schemes can be examined. A microprocessor-based fiber-optic engine control system was developed to provide precise control over valve and ignition timing. Initial shakedown testing with hydrogen/oxygen mixtures verified the need for Schelkin spirals in both the initiator and primary tubes to ensure rapid development of the detonation wave. Measured pressure wave time-of-flight indicated detonation velocities of 2.4 km/sec and 2.2 km/sec in the initiator and primary tubes, respectively. These values implied a fuel-lean mixture corresponding to an H2 volume fraction near 0.5. The axial distribution for the detonation velocity was found to be essentially constant along the primary tube. Time-resolved thrust profiles were also acquired for both underfilled and overfilled tube conditions. These profiles are consistent with previous time

  15. SU-E-T-558: An Exploratory RF Pulse Sequence Technique Used to Induce Differential Heating in Tissues Containing Iron Oxide Nanoparticles for a Possible Hyperthermic Adjuvant Effect to Radiotherapy

    Yee, S; Ionascu, D; Wilson, G [William Beaumont Hospital, Royal Oak, MI (United States); Thapa, R [Oakland University, Rochester, MI (United States)

    2014-06-01

    Purpose: In pre-clinical trials of cancer thermotherapy, hyperthermia can be induced by exposing localized super-paramagnetic iron oxide nanoparticles (SPION) to external alternating magnetic fields generated by a solenoid electrical circuit (Zhao et al., Theranostics 2012). Alternatively, an RF pulse technique implemented in a regular MRI system is explored as a possible hyperthermia induction technique . Methods: A new thermal RF pulse sequence was developed using the Philips pulse programming tool for the 3T Ingenia MRI system to provide a sinusoidal magnetic field alternating at the frequency of 1.43 kHz (multiples of sine waves of 0.7 ms period) before each excitation RF pulse for imaging. The duration of each thermal RF pulse routine was approximately 3 min, and the thermal pulse was applied multiple times to a phantom that contains different concentrations (high, medium and low) of SPION samples. After applying the thermal pulse each time, the temperature change was estimated by measuring the phase changes in the T1-weighted inversion-prepared multi-shot turbo field echo (TFE) sequence (TR=5.5 ms, TE=2.7 ms, inversion time=200 ms). Results: The phase values and relative differences among them changed as the number of applied thermal RF pulses increased. After the 5th application of the thermal RF pulse, the relative phase differences increased significantly, suggesting the thermal activation of the SPION. The increase of the phase difference was approximately linear with the SPION concentration. Conclusion: A sinusoidal RF pulse from the MRI system may be utilized to selectively thermally activate tissues containing super-paramagnetic iron oxide nanoparticles.

  16. 比例电磁阀流量滞环建模方法探究%Inquiry into Flow Hysteresis Modeling Approach of Proportional Solenoid Valve

    蔡胜年; 李海洋; 庞宝麟

    2014-01-01

    针对工业上广泛使用的比例电磁阀所存在的滞环曲线等问题造成的系统稳定性和控制品质的不利影响进行了研究,采用机制建模、基于PSO算法曲线参数辨识的建模以及基于神经网络的曲线拟合3种方法进行滞环曲线建模,并利用Matlab软件得到3种建模结果,对3种建模方法得到的建模结果与实测数据进行分析比较。结果表明:采用PSO曲线参数辨识方法最能表示实际滞环曲线,且该建模方法简单实用;该模型可用于对比例电磁阀的前馈控制,以达到减小或消除比例电磁阀流量滞环的目的。%Aiming at the proportional solenoid valves widely used in industry,the system stability and control quality of the nega-tive impact,which caused by hysteresis curve that existed in the valves,were studied. By using of mechanism modeling,curve param-eter identification based on Particle Swarm Optimization (PSO)algorithm modeling and neural network curve fitting of three methods, modeling was done for hysteresis curve,and three modeling results were gotten by using Matlab software. The modeling results obtained by the three methods were analyzed and compared with the practical measured data. The results show that to determine curve parameter identification based on PSO algorithm modeling do best to represent the actual hysteresis curve. This method is simple and practical. The model can be used for the feed-forward control of the proportional solenoid valve,for the purpose of decrease or eliminate flow hys-teresis of the valve.

  17. 直动型电磁阀吸力可靠性分析%Reliability Analyzing Method for Magnetic Suction of a Direct-Acting Solenoid Valve

    贾玥; 李宝盛

    2014-01-01

    A direct current solenoid valve was studied in this paper. Adopting finite element analysis software “Ansoft Maxwell” to build the 2D models of the solenoid valve, the magnetic induction intensity, mangnetic lines and suction curves under static magnet field were gained. The electromagnet suctions of all targets were calculated by orthogonal design method, using Ansoft Maxwell software; and then the reliability evaluation and factor analysis were applied on the simulation results. Also, the reliability evaluation was applied on the electromagnet suction data which were gained by testing. Finally, the simulation results and test data of electromagnet suction were compared and analyzed. The results proved that, after improving the simulation methods and narrowing down the range of each factor, the simulation results can authentically reflect the suction reliability.%以直流螺线管电磁阀为研究对象,利用电磁有限元软件Ansoft Maxwell对某种直动型电磁阀进行二维建模,并得出磁感应强度、磁力线分布图及静磁场下的吸力特性曲线。用正交设计法通过Ansoft Maxwell软件进行各指标的吸力计算,对得出吸力仿真计算值进行可靠性评估和因素分析;通过试验测试得到电磁阀吸力数据,对得出的吸力实测值也进行可靠性评估;后续对电磁阀吸力仿真计算值的可靠性评估和吸力实测值的可靠性评估进行了对比和分析。结果表明,通过改进仿真方法及缩小仿真计算时各因素取值范围,吸力仿真计算结果能真实地反映吸力可靠性。

  18. Pulse source requirements for OTDM systems

    Clausen, Anders; Poulsen, Henrik Nørskov; Oxenløwe, Leif Katsuo;

    2003-01-01

    A simulation model for investigating the impact of incoherent crosstalk due to pulse tail overlapping is proposed. Requirements to pulse width and pulse tail extinction ratio introducing a maximum of 1 dB penalty is extracted.......A simulation model for investigating the impact of incoherent crosstalk due to pulse tail overlapping is proposed. Requirements to pulse width and pulse tail extinction ratio introducing a maximum of 1 dB penalty is extracted....

  19. 直动型气动电磁阀综合性能测试系统研究%Study on integrative performance test system for direct-driven pneumatic solenoid valve

    陆艺; 郭斌; 潘小旺; 范伟军

    2011-01-01

    针对目前国内对直动式气动电磁阀测试存在的不足问题,采用高速数据采集系统,应用计算机控制技术,设计了电磁阀综合性能检测系统.测试项目主要有动态特性检测、密封性检测、疲劳寿命测试,并首次引入了最低先导压力的测试,突破了以往只针对单个参数测试的局限.为验证系统的准确性,设计完善了一种基于MATLAB/Simulink的电磁阀动态仿真模型,可应用于电磁阀设计时的多参数仿真和优化设计.运用仿真模型和测试系统,测试、分析了气路压力条件对电磁阀性能的影响,确定了电磁阀测试或使用时的最佳气路压力条件.实验结果表明:该系统能很好地对电磁阀的综合性能进行评判,系统时间分辨率达到0.1ms,压力分辨率0.1 kPa.%To solve the problem of measuring solenoid valve at present, an integrative performance test system for solenoid valve was designed using high-speed data collection system and computer control technology. The test items for solenoid valve mainly are dynamic characteristic, sealing performance and fatigue life test, and the minimum pilot pressure test is introduced for the first time, which breaks through the limitation that only single parameter of solenoid valve was tested formerly. To verify the system accuracy, a dynamic simulation model of solenid valve was designed and perfected based on MATLAB/Simulink. The model can be used for multi-parameter simulation and optimum design of solenoid valve. Using the simulation model and test system, the influence of gaspath pressure on the characteristics of solenoid valve is measured and analyzed. The best gaspath pressure condition for using or testing solenoid valve is determined. Experiment results show that the integrative performance of solenoid valve can be evaluated very well. The time resolution of the system is 0.1 ms and its pressure resolution is 0.1 kPa.

  20. Measuring low frequency alternating magnetic field in solenoid by two Hall sensors%利用双霍尔探头测螺线管中低频交变磁场

    张立辉; 张攀; 乐宏昊

    2014-01-01

    A method of measuring magnetic field with two Hall sensors in the Hall Effect experi-ment was proposed .The low frequency alternating magnetic field in a solenoid was studied after cali-bration .The features of the low frequency alternating magnetic field in the solenoid were analyzed .It offered a new thought for students in measuring weak low frequency electromagnetic radiation .%在霍尔效应实验中利用双霍尔探头测磁场,通过对磁场定标,研究了螺线管中低频交变磁场,并分析了螺线管中低频交变磁场的分布特征,为学生测量低频弱电磁辐射提供了新的思路。