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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. Note: High temperature pulsed solenoid valve.

    Shen, Wei; Sulkes, Mark

    2010-01-01

    We have developed a high temperature pulsed solenoid valve with reliable long term operation to at least 400 degrees C. As in earlier published designs, a needle extension sealing a heated orifice is lifted via solenoid actuation; the solenoid is thermally isolated from the heated orifice region. In this new implementation, superior sealing and reliability were attained by choosing a solenoid that produces considerably larger lifting forces on the magnetically actuated plunger. It is this property that facilitates easily attainable sealing and reliability, albeit with some tradeoff in attainable gas pulse durations. The cost of the solenoid valve employed is quite low and the necessary machining quite simple. Our ultimate level of sealing was attained by making a simple modification to the polished seal at the needle tip. The same sealing tip modification could easily be applied to one of the earlier high T valve designs, which could improve the attainability and tightness of sealing for these implementations. PMID:20113132

  3. 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.

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

    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.

  5.  Note: High temperature pulsed solenoid valve

    Shen, Wei; Sulkes, Mark

    2010-01-01

    We have developed a high temperature pulsed solenoid valve with reliable long term operation to at least 400 °C. As in earlier published designs, a needle extension sealing a heated orifice is lifted via solenoid actuation; the solenoid is thermally isolated from the heated orifice region. In this new implementation, superior sealing and reliability were attained by choosing a solenoid that produces considerably larger lifting forces on the magnetically actuated plunger. It is this property that facilitates easily attainable sealing and reliability, albeit with some tradeoff in attainable gas pulse durations. The cost of the solenoid valve employed is quite low and the necessary machining quite simple. Our ultimate level of sealing was attained by making a simple modification to the polished seal at the needle tip. The same sealing tip modification could easily be applied to one of the earlier high T valve designs, which could improve the attainability and tightness of sealing for these implementations.

  6. Conceptual design of a 20 Tesla pulsed solenoid for a laser solenoid fusion reactor

    Design considerations are described for a strip wound solenoid which is pulsed to 20 tesla while immersed in a 20 tesla bias field so as to achieve within the bore of the pulsed solenoid at net field sequence starting at 20 tesla and going first down to zero, then up to 40 tesla, and finally back to 20 tesla in a period of about 5 x 10-3 seconds. The important parameters of the solenoid, e.g., aperture, build, turns, stored and dissipated energy, field intensity and powering circuit, are given. A numerical example for a specific design is presented. Mechanical stresses in the solenoid and the subsequent choice of materials for coil construction are discussed. Although several possible design difficulties are not discussed in this preliminary report of a conceptual magnet design, such as uniformity of field, long-term stability of insulation under neutron bombardment and choice of structural materials of appropriate tensile strength and elasticity to withstand magnetic forces developed, these questions are addressed in detail in the complete design report and in part in reference one. Furthermore, the authors feel that the problems encountered in this conceptual design are surmountable and are not a hindrance to the construction of such a magnet system

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

    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

  8. 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.

  9. 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.

  10. Implementation of a new composite pulse for excitation in fast proton spectroscopic imaging at 15 T

    Starčuk jr., Zenon; Starčuk, Zenon; Starčuková, Jana; Krupa, P.

    Seattle: ISMRM, 2006, s. 3070. ISSN 1545-4436. [ISMRM 14th Scientific Meeting and Exhibition. Seattle (US), 06.05.2006-12.05.2006] Institutional research plan: CEZ:AV0Z20650511 Keywords : fast MR spectroskopic imaging * composite pulses Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  11. 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.

  12. Transporting laser-accelerated protons by a pulsed solenoid to a CH- DTL

    This study demonstrates the transporting and focusing of laser-accelerated protons at energies of ten to several tens of MeV, by a pulsed magnetic solenoid with a field gradient up to 18 T. The unique features of the protons distribution like extremely small emittances and high yield of the order of 1013 protons per shot, make them attractive for study. With respect to transit energies further acceleration by matching into rf linac seems adequate. The bunch injection into a proposed CH- structure is under investigation at IAP Frankfurt. Options and simulation tools are presented.

  13. A unique 30 Tesla single-solenoid pulsed magnet instrument for x-ray studies

    Islam, Zahirul; Capatina, Dana; Ruff, Jacob; Das, Ritesh; Nojiri, Hiroyuki; Narumi, Yasuo

    2011-03-01

    We present a dual-cryostat pulsed-magnet instrument at the Advanced Photon Source (APS) with unique capabilities. The dual-cryostat independently cools the solenoid (Tohoku design) using liquid nitrogen and the sample using a closed-cycle refrigerator, respectively. Liquid nitrogen (LN) cooling allows a repetition rate of seven minutes for peak fields of 30 Tesla. The system is unique in that the LN cryostat incorporates a double-funnel vacuum tube passing through the solenoid's bore preserving the entire angular range allowed by the magnet. This scheme is advantageous in that it allows the applied magnetic field to be parallel to the scattering plane complementing typical split-pair magnets with fields normal to the scattering plane. Performance of the coils along with preliminary x-ray diffraction and spectroscopic studies will be presented. Use of the APS is supported by the U. S. DOE, Office of Science, under Contract No. DE-AC02-06CH11357. The work was supported in part by ICC-IMR, Tohoku University.

  14. High field laser heated solenoids

    A 10 kJ pulsed CO2 laser and 3.8 cm bore, 15 T, 8 μs rise time, 1-m long fast solenoid facility has been constructed to demonstrate the feasibility of using long wavelength lasers to heat magnetically confined plasmas. The most critical physics requirement is the necessity of creating and maintaining an on-axis electron density minimum to trap the axially directed laser beam. Satisfaction of this requirement has been demonstrated by heating 1.5 Torr deuterium fill plasmas in 2.7 cm bore plasma tubes to line energies of approximately 1 kJ/m. (Auth.)

  15. Development of a single-shot pulsed power supply for a solenoid producing magnetic field to guide a pulsed electron beam

    Design and development of a single-shot pulsed power supply has been done for a solenoid producing magnetic field up to 1 Tesla. The magnetic field is used to guide a pulsed electron beam generated in a Marx generator. (author)

  16. 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.

  17. 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.

  18. Controlling Charge and Current Neutralization of an Ion Beam Pulse in a Background Plasma by Application of a Solenoidal Magnetic Field I: Weak Magnetic Field Limit

    Kaganovich, I. D., Startsev, E. A., Sefkow, A. B., Davidson, R. C.

    2008-10-10

    Propagation of an intense charged particle beam pulse through a background plasma is a common problem in astrophysics and plasma applications. The plasma can effectively neutralize the charge and current of the beam pulse, and thus provides a convenient medium for beam transport. The application of a small solenoidal magnetic field can drastically change the self-magnetic and self- electric fields of the beam pulse, thus allowing effective control of the beam transport through the background plasma. An analytic model is developed to describe the self-magnetic field of a finite- length ion beam pulse propagating in a cold background plasma in a solenoidal magnetic field. The analytic studies show that the solenoidal magnetic field starts to infuence the self-electric and self-magnetic fields when ωce > ωpeβb, where ωce = eβ/mec is the electron gyrofrequency, ωpe is the electron plasma frequency, and βb = Vb/c is the ion beam velocity relative to the speed of light. This condition typically holds for relatively small magnetic fields (about 100G). Analytical formulas are derived for the effective radial force acting on the beam ions, which can be used to minimize beam pinching. The results of analytic theory have been verified by comparison with the simulation results obtained from two particle-in-cell codes, which show good agreement.

  19. Some options for the muon collider capture and decay solenoids

    This report discusses some of the problems associated with using solenoid magnets to capture the secondary particles that are created when an intense beam of 8 to 10 GeV protons interacts with the target at the center of the capture region. Hybrid capture solenoids with inductions of 28 T and a 22T are described. The first 14 to 15 T of the solenoid induction will be generated by a superconducting magnet. The remainder of the field will be generated by a Bitter type of water cooled solenoid. The capture solenoids include a transition section from the high field solenoid to a 7 T decay channel where pions and kaons that come off of the target decay into muons. A short 7 T solenoidal decay channel between the capture solenoid system and the phase rotation system is described. A concept for separation of negative and positive pions and kaons is briefly discussed

  20. The Wisconsin Pegasus solenoid

    A 1.6 m long x 0.1m diameter coil has just been constructed by the NHMFL for the University of Wisconsin Pegasus Tokamak. It will form the central solenoid for the high plasma energy density fusion machine. The magnet consists of two layers of Glidcop conductor, reinforced with S2 glass, carbon fiber and steel. Normal operating parameters will be 14 T in a 58 mm bore with a number of pulses to 20 T+. Current densities will approach 1 kA/mm2 and the stored energy will be >2 MJ. The philosophy behind the design will be presented and details of the construction and testing will be shown. (orig.)

  1. Adrenal mass evaluation at 1.5 T

    At 1.5 T (Signa, General Electric), 30 adrenal masses were evaluated with spin-echo imaging in an effort to differentiate adenomas from nonadenomas. There were eight nonhyperfunctioning adenomas, four hyperfunctioning adenomas, eight metastases, three primary adenocarcinomas, four pheochromocytomas, two infectious masses, and one cystic ganglioneuroma. T1-weighted (repetition time [TR]/echo time [TE] = 500/20,25 msec) and T2-weighted (TR/TE = 2,000, 2,500/80) pulse sequences were used. T2 relaxation time and adrenal mass signal intensity were measured and compared with those of liver, fat, and muscle. Adenomas could not be distinguished from nonadenomas at any signal intensity ratios. With T2 relaxation times and a cutoff of 60 msec, adenomas could be distinguished from nonadenomas with a 92% specificity and a 94% sensitivity. At 1.5 T, the adrenal mass T2 relaxation time should be used in differentiating adenomas from nonadenomas

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. Laser solenoid radiation test facility

    The Laser Solenoid Radiation Test Facility (LSRTF) is a concept based on a pulsed plasma source of neutrons, alpha particles, and bremsstrahlung and is characterized by a moderate radiation flux and a large test sample volume. The LSRTF is intermediate in its size, technology, and availability (1985-1990), and consequently has potential for bridging the gap between small present day accelerator-target sources and a large pulsed plasma engineering research facility in the 1990's. It also has important potential as a compact engineering test reactor for realistic operational testing of integrated subsystems for a linear fusion reactor. Its design, performance and operating characteristics are discussed in the present paper. The necessary development programs to bring such a facility into timely operation are also described. (Auth.)

  7. Laser ion source with solenoid field

    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

  8. 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.

  9. The DARHT-II-DC Final Focus Solenoid

    Paul, A.C.

    2000-03-06

    The baseline DARHT2 external beam uses a pulsed solenoid final focus lens. The design of this lens was presented at TOS2 and has been considered as the final focus lens in all of the Livermore beamlines for DARHT2. In this note, we consider a new alternative DC final focus solenoid. A crude comparison between the parameters of these two designs is given in table 1. The small spot size required by the radiography and the small drift distance available between the last magnetic focusing element and the final focus solenoid imposed by the close proximity between the DARHT 2 building and the DARHT 1 axis, implies a short focal length solenoid. This in turn requires that the final focus solenoid mount inside the re-entrant cavity of the containment vessel in order to accommodate the 0.9 meter conjugate: figure 1. The ID of this cavity is 13.88 inches (35.25 cm).

  10. 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... ...

  11. The Results of Tests of the MICE Spectrometer Solenoids

    The Muon Ionization Cooling Experiment (MICE) spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The spectrometer magnets are the largest magnets in both mass and surface area within the MICE ooling channel. Like all of the other magnets in MICE, the spectrometer solenoids are kept cold using 1.5 W (at 4.2 K) pulse tube coolers. The MICE spectrometer solenoid is quite possibly the largest magnet that has been cooled using small coolers. Two pectrometer magnets have been built and tested. This report discusses the results of current and cooler tests of both magnets.

  12. LCLS Gun Solenoid Design Considerations

    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.

  13. The Results of Recent MICE Superconducting Spectrometer Solenoid Test

    The MICE spectrometer solenoid magnets will be the first magnets to be installed within the MICE cooling channel. The MICE spectrometer solenoids may be the largest magnets that have been cooled using small two stage coolers. During the previous test of this magnet, the cooler first stage temperatures were too high. The causes of some of the extra first stage heat load has been identified and corrected. The rebuilt magnet had a single stage GM cooler in addition to the three pulse tube coolers. The added cooler reduces the temperature of the top of the HTS leads, the shield and of the first stage of the pulse tube coolers.

  14. Dense Metal Plasma in a Solenoid for Ion Beam Neutralization

    Anders, Andre; Kauffeldt, Marina; Oks, Efim M.; Roy, Prabir K.

    2010-10-30

    Space-charge neutralization is required to compress and focus a pulsed, high-current ion beam on a target for warm dense matter physics or heavy ion fusion experiments. We described approaches to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary space-charge compensating electrons. Among the options are plasma injection from pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means, by an array of movable Langmuir probes, by a small single probe, and by evaluating Stark broadening of the Balmer H beta spectral line. In the main approach described here, the plasma is produced at several cathode spots distributed azimuthally on the ring cathode. It is shown that the plasma is essentially hollow, as determined by the structure of the magnetic field, though the plasma density exceeds 1014 cm-3 in practically all zones of the solenoid volume if the ring electrode is placed a few centimeters off the center of the solenoid. The plasma is non-uniform and fluctuating, however, since its density exceeds the ion beam density it is believed that this approach could provide a practical solution to the space charge neutralization challenge.

  15. Muscle Motion Solenoid Actuator

    Obata, Shuji

    It is one of our dreams to mechanically recover the lost body for damaged humans. Realistic humanoid robots composed of such machines require muscle motion actuators controlled by all pulling actions. Particularly, antagonistic pairs of bi-articular muscles are very important in animal's motions. A system of actuators is proposed using the electromagnetic force of the solenoids with the abilities of the stroke length over 10 cm and the strength about 20 N, which are needed to move the real human arm. The devised actuators are based on developments of recent modern electro-magnetic materials, where old time materials can not give such possibility. Composite actuators are controlled by a high ability computer and software making genuine motions.

  16. 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.

  17. Laser solenoid: an alternate use of lasers in fusion power

    A unique laser assisted fusion approach is under development at Mathematical Sciences Northwest, Inc. (MSNW). This approach captures one of the most developed aspects of high energy laser technology, the efficient, large, scalable, pulsed electron beam initiated, electric discharge, CO2 infrared laser. This advanced technology is then combined with the simple geometry of a linear magnetic confinement system. The laser solenoid concept will be described, current work and experimental progress will be discussed, and the technological problems of building such a system will be assessed. Finally a comparison will be made of the technology and economics for the laser solenoid and alternative fusion approaches

  18. 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 remai...

  19. Solenoidal fusion system

    This invention discloses apparatus and methods to produce nuclear fusion utilizing fusible material in the form of high energy ion beams confined in magnetic fields. For example, beams of deuterons and tritons are injected in the same direction relative to the axis of a vacuum chamber. The ion beams are confined by the magnetic fields of long solenoids. The products of the fusion reactions, such as neutrons and alpha particles, escape to the wall surrounding the vacuum chamber, producing heat. The momentum of the deuterons is approximately equal to the momentum of the tritons, so that both types of ions follow the same path in the confining magnetic field. The velocity of the deuteron is sufficiently greater than the velocity of the triton so that overtaking collisions occur at a relative velocity which produces a high fusion reaction cross section. Electrons for space charge neutralization are obtained by ionization of residual gas in the vacuum chamber, and additionally from solid material (Irradiated with ultra-violet light or other energetic radiation) adjacent to the confinement region. For start-up operation, injected high-energy molecular ions can be dissociated by intense laser beam, producing trapping via change of charge state. When sufficiently intense deuteron and triton beams have been produced, the laser beam can be removed, and subsequent change of charge state can be achieved by collisions

  20. A Seemingly Simple Task: Filling a Solenoid Volume in Vacuum with Dense Plasma

    Space-charge neutralization of a pulsed, high-current ion beam is required to compress and focus the beam on a target for warm dense matter physics or heavy ion fusion experiments. We described attempts to produce dense plasma in and near the final focusing solenoid through which the ion beam travels, thereby providing an opportunity for the beam to acquire the necessary charge-compensating electrons. Among the options are plasma injection from four pulsed vacuum arc sources located outside the solenoid, and using a high current (> 4 kA) pulsed vacuum arc plasma from a ring cathode near the edge of the solenoid. The plasma distribution is characterized by photographic means and by an array of movable Langmuir probes. The plasma is produced at several cathode spots distributed azimuthally on the ring cathode. Beam neutralization and compression are accomplished, though issues of density, uniformity, and pulse-to-pulse reproducibly remain to be solved.

  1. Fusion--fission neutronics calculations for the laser solenoid

    Neutron transport calculations are presented for several laser solenoid blanket configurations containing fast-fission lattices of uranium and thorium. The presence of a small-bore pulsed magnet and a small first-wall radius results in unique neutronics characteristics relative to other fusion concepts. Parametric calculations were completed to determine the effects of increasing the pulsed magnet thickness and of varying other key blanket parameters. Attractive fissile breeding rates could be achieved for blankets with a wide range of energy multiplication under the constraints of a tritium breeding ratio of about unity and a pulsed magnet thickness of about 3 cm

  2. Phase space rotation with solenoids and quadrupoles

    A standard five-quadrupole phase-space rotation system is discussed and compared with a possible alternative - two superconducting solenoids which accomplish the same job in a different way. In some laboratories the solenoid system may be advantageous

  3. The ATLAS solenoid approaches its final position

    Maximilien Brice

    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.

  4. 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.

  5. The ALICE cavern and solenoid

    Maximilien Brice

    2003-01-01

    The ALICE experiment, one of the four major experiments of CERN's LHC project, will be housed in the cavern that once contained the L3 experiment at the LEP accelerator. The huge solenoid is the only remaining piece of the L3 experiment and will be used by ALICE.

  6. Superconducting curved transport solenoid with dipole coils for charge selection of the muon beam

    Highlights: • Superconducting curved transport solenoid. • Muon charge selection by superimposed dipole field. • World strongest pulsed muon source. -- Abstract: At the J-PARC Muon Science Facility (MUSE) the Super-Omega muon beamline is now under construction in the experimental hall No. 2 of the Materials and Life Science Facility building. Muons up to 45 MeV/c will be extracted with a large acceptance solid angle to produce the world highest intensity pulsed muon beam. This beamline comprises three parts, a normal-conducting capture solenoid, a superconducting curved transport solenoid and an axial focusing solenoid. Since only solenoids are used, both surface μ+ and cloud μ− are extracted simultaneously. To accommodate future experiments that would only require either μ+ or μ− beam, two dipole coils located on the straight section of the curved solenoid provide the muon charge selection by directing one of the beam onto the solenoid inner-wall. The design parameters, the construction status and the initial beam commissioning are reported

  7. Superconducting curved transport solenoid with dipole coils for charge selection of the muon beam

    Strasser, P., E-mail: patrick.strasser@kek.jp [Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Ikedo, Y.; Miyake, Y.; Shimomura, K.; Kawamura, N.; Nishiyama, K.; Makimura, S.; Fujimori, H.; Koda, A.; Nakamura, J.; Nagatomo, T. [Muon Science Laboratory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Adachi, T. [Department of Physics, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Pant, A.D. [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu 400-8511 (Japan); Ogitsu, T. [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Makida, Y.; Yoshida, M. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Sasaki, K. [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Okamura, T. [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); J-PARC Center, 2-4 Shirane Shirakata, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); and others

    2013-12-15

    Highlights: • Superconducting curved transport solenoid. • Muon charge selection by superimposed dipole field. • World strongest pulsed muon source. -- Abstract: At the J-PARC Muon Science Facility (MUSE) the Super-Omega muon beamline is now under construction in the experimental hall No. 2 of the Materials and Life Science Facility building. Muons up to 45 MeV/c will be extracted with a large acceptance solid angle to produce the world highest intensity pulsed muon beam. This beamline comprises three parts, a normal-conducting capture solenoid, a superconducting curved transport solenoid and an axial focusing solenoid. Since only solenoids are used, both surface μ{sup +} and cloud μ{sup −} are extracted simultaneously. To accommodate future experiments that would only require either μ{sup +} or μ{sup −} beam, two dipole coils located on the straight section of the curved solenoid provide the muon charge selection by directing one of the beam onto the solenoid inner-wall. The design parameters, the construction status and the initial beam commissioning are reported.

  8. Effect of solenoidal magnetic field on drifting laser plasma

    Takahashi, Kazumasa; Sekine, Megumi [Tokyo Institute of Technology, Yokohama 226-8502 (Japan); Okamura, Masahiro [Brookhaven National Laboratory, Upton, NY 11973 (United States) and RIKEN, Wako-shi, Saitama 351-0198 (United States); Cushing, Eric [Pennsylvania State University, University Park, PA 16802 (United States); Jandovitz, Peter [Cornell University, Ithaca, NY 14853 (United States)

    2013-04-19

    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.

  9. 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.

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

    A pulsed high field solenoid was used in a laser-proton acceleration experiment to collimate and transport the proton beam that was generated at the irradiation of a flat foil by a high intensity laser pulse. 1012 particles at an energy of 2.3 MeV could be caught and transported over a distance of more than 240 mm. Strong space charge effects occur, induced by the high field of the solenoid that forces all co-moving electrons down the the solenoid's axis, building up a strong negative space charge that interacts with the proton beam. This leads to an aggregation of the proton beam around the solenoid's axis and therefore to a stronger focusing effect. The collimation and transport of laser-accelerated protons is the first step to provide these unique beams for further applications like post-acceleration by conventional accelerator structures.

  11. Confinement of laser plasma by solenoidal field for laser ion source

    A laser ion source can provide high current, highly charged ions with a simple structure. However, it was not easy to control the ion pulse width. To provide a longer ion beam pulse, the plasma drift length, which is the distance between laser target and extraction point, has to be extended and as a result the plasma is diluted severely. Previously, we applied a solenoid field to prevent reduction of ion density at the extraction point. Although a current enhancement by a solenoid field was observed, plasma behavior after a solenoid magnet was unclear because plasma behavior can be different from usual ion beam dynamics. We measured a transverse ion distribution along the beam axis to understand plasma motion in the presence of a solenoid field.

  12. LIL-W: Positron conversion target and solenoid (pictures 01 and 04).

    Laurent Guiraud

    1997-01-01

    In the direction of the beam, from right to left: a steering dipole (DHZ.25); the arm, at 45 deg, of a wire scanner which measures beam size; the conversion target, housed in the small tank with a window, where positrons are produced; immediately afterwards, invisible inside the vacuum chamber, is a pulsed solenoid to focus the emerging positrons; finally, a large solenoid, consisting of 3 pancakes, further focuses the positrons. Towards the left, the linac LIL-W, its accelerating structure hidden under a continuous outer solenoid mantle.

  13. Developmentof the 15 T Nb3Sn dipole HD2

    Caspi, S.; Cheng, D.W.; Dietderich, D.R.; Hafalia, A.R.; Hannaford, C.R.; Higley, H.; Lietzke, A.F.; Lizarazo, J.; McInturff, A.D.; Sabbi, G.; Ferracin, P.

    2008-06-01

    The Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) is continuing the development of HD2, a 1 m long Nb{sub 3}Sn dipole generating a dipole field of 15 T in a 36 mm clear bore. With tilted (flared) ends to avoid obstructing the beam path, HD2 represents a step towards the development of cost effective accelerator quality magnets. The design has been optimized to minimize geometric harmonics and to address iron saturation and conductor magnetization effects. The support structure is based on an external aluminum shell, pre-tensioned with pressurized bladders and interference keys. Aluminum axial rods and stainless steel end plates provide longitudinal support to the coil ends during magnet excitation. This paper reports on field quality optimization and magnet parameters. The design and fabrication of the coil and structure components, and results from coil winding, reaction, and potting are also presented.

  14. Quench anaylsis of MICE spectrometer superconducting solenoid

    Kashikhin, Vladimir; Bross, Alan; /Fermilab; Prestemon, Soren; / /LBL, Berkeley

    2011-09-01

    MICE superconducting spectrometer solenoids fabrication and tests are in progress now. First tests of the Spectrometer Solenoid discovered some issues which could be related to the chosen passive quench protection system. Both solenoids do not have heaters and quench propagation relied on the 'quench back' effect, cold diodes, and shunt resistors. The solenoids have very large inductances and stored energy which is 100% dissipated in the cold mass during a quench. This makes their protection a challenging task. The paper presents the quench analysis of these solenoids based on 3D FEA solution of coupled transient electromagnetic and thermal problems. The simulations used the Vector Fields QUENCH code. It is shown that in some quench scenarios, the quench propagation is relatively slow and some areas can be overheated. They describe ways of improving the solenoids quench protection in order to reduce the risk of possible failure.

  15. Progress in ATLAS central solenoid magnet

    Yamamoto, A; Makida, Y; Tanaka, K; Haruyama, T; Yamaoka, H; Kondo, T; Mizumaki, S; Mine, S; Wada, K; Meguro, S; Sotoki, T; Kikuchi, K; ten Kate, H H J

    2000-01-01

    The ATLAS central solenoid magnet is being developed to provide a magnetic field of 2 Tesla in the central tracking volume of the ATLAS detector under construction at the CERN/LHC project. The solenoid coil design features high-strength aluminum stabilized superconductor to make the coil thinnest while maintaining its stability and the pure-aluminum strip technique for quench protection and safety. The solenoid coil is installed in a common cryostat with the LAr calorimeter in order to minimize the cryostat wall. A transparency of 0.66 radiation length is achieved with these integrated efforts. The progress in the solenoid coil fabrication is reported. (8 refs).

  16. A Solenoid Capture System for Neutrino Production

    This paper describes the use of a high field solenoidal magnet to capture secondary pions from the production target. The captured pions subsequentially decay to produce the neutrino beam. A pion capture system using a high field solenoid magnet has been proposed for the muon collider. This technology would also be available for neutrino beam production. It will be shown that a high field solenoid would produce a larger flux of neutrinos with energy, Eν e, (bar ν)e flux contamination in the solenoid neutrino beam is only 0.15%

  17. Solenoid and non-solenoid protein recognition using stationary wavelet packet transform

    Vo, AN; Nguyen, Nha; Huang, Heng

    2010-01-01

    Motivation: Solenoid proteins are emerging as a protein class with properties intermediate between structured and intrinsically unstructured proteins. Containing repeating structural units, solenoid proteins are expected to share sequence similarities. However, in many cases, the sequence similarities are weak and non-detectable. Moreover, solenoids can be degenerated and widely vary in the number of units. So that it is difficult to detect them. Recently, several solenoid repeats detection m...

  18. 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.

  19. Laser-heated solenoid fusion

    Since the suggestion by Dawson, Hertzberg, and Kidder that high-energy CO2 lasers could be used to heat magnetically confined plasma columns to thermonuclear temperatures, a great deal of theoretical and experimental work has been performed. In this paper we first review the experiments on the basic laser-plasma interaction phenomena, in which lasers with energies up to 1 kJ have been used to produce plasmas at n/sub e/ greater than 1018 and T/sub e/ greater than 200 eV. The second part reviews fusion reactor studies based on the laser solenoid

  20. 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

  1. Laser heated solenoid as a neutron source facility

    Conceptual designs are presented for a radiation test facility based on a laser heated plasma confined in a straight solenoid. The thin plasma column, a few meters in length and less than a centimeter in diameter, serves as a line source of neutrons. Test samples are located within or just behind the plasma tube, at a radius of 1-2 cm from the axis. The plasma is heated by an axially-directed powerful long-wavelength laser beam. The plasma is confined radially in the intense magnetic field supplied by a pulsed solenoid surrounding the plasma tube. The facility is pulsed many times a second to achieve a high time-averaged neutron flux on the test samples. Based on component performance achievable in the near term (e.g., magnetic field, laser pulse energy) and assuming classical physical processes, it appears that average fluxes of 1013 to 1014 neutrons/cm2-sec can be achieved in such a device. The most severe technical problems in such a facility appear to be rapid pulsing design and lifetime of some electrical and laser components

  2. ATLAS superconducting toroids and solenoid

    ten Kate, H H J

    2005-01-01

    The ATLAS particle detector in the Large Hadron Collider at CERN features a hybrid system of four superconducting magnets: a Central Solenoid surrounded by 2 End-cap Toroids and a Barrel Toroid. The magnet system dimensions are 20 m in diameter and 26 m in length. With its 1.55 GJ stored energy in air, it actually is the largest superconducting magnet in the world. The construction of the magnets has started in 1998 and will end in 2006 with the completion of the installation underground. Currently, in October 2004, practically all magnet parts are manufactured and delivered to CERN for final integration. The first two out of 8 full size 25*5 m/sup 2/ size coils for the Barrel Toroid have been completed and tested while the other 6 are near to completion as well. The production of the so- called End-Cap Toroids is progressing well. The Central Solenoid is complete and ready for installation. The installation underground of the entire system including its services has commenced. In the paper the main features ...

  3. 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)

  4. The static and nonstatic electrical solenoids

    We propose the set of charge and current densities which realize static and nonstatic electrical solenoids. Their properties are discussed. The question on the physical meaning of the electromagnetic potentials outside the solenoids and their experimental verification remains to be opened. 19 refs.; 4 figs

  5. 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.

  6. 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}.

  7. Electron beam solenoid reactor concept

    The electron Beam Heated Solenoid (EBHS) reactor is a linear magnetically confined fusion device in which the bulk or all of the heating is provided by a relativistic electron beam (REB). The high efficiency and established technology of the REB generator and the ability to vary the coupling length make this heating technique compatible with several radial and axial enery loss reduction options including multiple-mirrors, electrostatic and gas end-plug techniques. This paper addresses several of the fundamental technical issues and provides a current evaluation of the concept. The enhanced confinement of the high energy plasma ions due to nonadiabatic scattering in the multiple mirror geometry indicates the possibility of reactors of the 150 to 300 meter length operating at temperatures > 10 keV. A 275 meter EBHS reactor with a plasma Q of 11.3 requiring 33 MJ of beam eneergy is presented

  8. P-31 MR spectroscopy of the normal human heart at 1.5 T

    The determination of metabolite ratios and intracellular pH from phosphorus-31 NMR spectra of the human heart is extremely difficult. The authors of this paper develop a reliable and reproducible protocol for studying P-31 metabolism in the human heart. All experiments were performed with use of a regular 1.5-T NMR imager with a 10-14-cm diameter P-31 surface coil. The proton body coil was used for scout images, localized shimming on the heart, and H-1 decoupling. Localization comprised one-dimensional phase encoding with use of 32 phase-encoding steps over a field of view of 32 cm. Localization in the other two directions was achieved by column (8*8-6*6 cm) selection with inversion pulses combined with an appropriate add/subtract scheme. All pulses were of the adiabatic fast-passage type. The spectra were ECG triggered (TR = 3-4 seconds). Total acquisition time was 27-36 minutes

  9. A pulsed magnetic field test facility for conductors and joints

    The International Thermonuclear Experimental Reactor (ITER) and, in the US, the Tokamak Physics Experiment (TPX) fusion programs both require conductor and joint testing in a pulsed magnetic background field in order to demonstrate that these components can operate successfully in a simulated, fusion-machine environment. Here, a pulsed magnetic field test facility is under construction at Massachusetts Institute of Technology for testing large scale cable-in-conduit superconductor and joint samples. Separate, demountable split-pair solenoid and saddle coils provide a combination of fields which can be either transverse of parallel to the sample axis. The solenoid and saddle magnets together can provide transverse peak fields as high as 8.4 T. Peak parallel fields of 6.6 T can be generated with the solenoid alone. Ramp-up rates of 1.5 T/s and ramp-down rates of 20 T/s are possible. Sample currents up to 50 kA are provided by a superconducting current transformer. The sample is connected to the transformer secondary through a pair of low resistance joints. Supercritical helium is provided to the sample at flow rates up to 20 g/s, pressures up to 1 MPa, and temperatures from 4.7 to 10 K. Programmable logic controllers provide coordination of the magnetic field, sample current, and helium flow rate and temperature in the sample. Sample and facility instrumentation signals are processed and data is stored on a workstation-based data acquisition system with comprehensive data reduction capability. Facility details and status are described

  10. Present status of cryogenic system for superconducting solenoid at J-PARC MUSE

    Muon Science laboratory at Material Life Science Facility is now under operation in J-PARC. The conventional muon channel, which contains the superconducting solenoid cooled by on-line He refrigeration system, can provide the world strongest pulsed muon beam from 4 to 120 MeV/c. In this report we will describe the present status of this system briefly. (author)

  11. MICE Spectrometer Solenoid Magnetic Field Measurements

    Leonova, M. [Fermilab

    2013-09-01

    The Muon Ionization Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with an absolute measurement accuracy of 0.1%. To measure emittances, MICE uses two solenoidal spectrometers, with Solenoid magnets designed to have 4 T fields, uniform at 3 per mil level in the tracking volumes. Magnetic field measurements of the Spectrometer Solenoid magnet SS2, and analysis of coil parameters for input into magnet models will be discussed.

  12. Embedded Solenoid Transformer for Power Conversion

    2015-01-01

    A resonant power converter for operation in the radio frequency range, preferably in the VHF, comprises at least one PCB-embedded transformer. The transformer is configured for radio frequency operation and comprises a printed circuit board defining a horizontal plane, the printed circuit board...... comprising at least two horizontal conductive layers separated by an isolating layer, a first embedded solenoid forming a primary winding of the transformer and a second embedded solenoid being arranged parallel to the first solenoid and forming a secondary winding of the transformer, wherein the first and...

  13. 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.

  14. The focusing properties of solenoid lenses

    Solenoids show inevitability their spherical aberration, which increases beam effective emittance. In this work the author make efforts to improve field quality in different ways. Calculations tell that increasing gap size of pole pieces or taping magnet poles can obviously reduce coefficient of spherical aberration. The equivalent parameters of solenoid lenses are calculated according to axial magnetic field pattern of lenses; they only relate to its geometry, independent of its magnetic field inductivity strength

  15. Advances in laser solenoid fusion reactor design

    The laser solenoid is an alternate fusion concept based on a laser-heated magnetically-confined plasma column. The reactor concept has evolved in several systems studies over the last five years. We describe recent advances in the plasma physics and technology of laser-plasma coupling. The technology advances include progress on first walls, inner magnet design, confinement module design, and reactor maintenance. We also describe a new generation of laser solenoid fusion and fusion-fission reactor designs

  16. Laser solenoid fusion--fission design

    The dependence of breeding performance on system engineering parameters is examined for laser solenoid fusion-fission reactors. Reactor performance is found to be relatively insensitive to most of the engineering parameters, and compact designs can be built based on reasonable technologies. Point designs are described for the prototype series of reactors (mid-term technologies) and for second generation systems (advanced technologies). It is concluded that the laser solenoid has a good probability of timely application to fuel breeding needs

  17. D0 Solenoid Commissioning September 1998

    Rucinski, R.; /Fermilab

    1998-10-12

    D-Zero installed a new 2 Tesla superconducting solenoid magnet into the central tracking region of the D-Zero detector. This report documents the cryogenic performance of the superconducting solenoid during its first cryogenic operation at Fermilab. By necessity, the liquid helium refrigerator was also operated. This was the second time the refrigerator plant has been operated. The refrigerator's performance is also documented herein.

  18. The Engineering Design of the 1.5 m Diameter Solenoid for the MICE RFCC Modules

    Wang, L; Green, M A; Xu, F Y; Wu, H; Li, L.K.; Gou, C.S.; Liu, C. S.; Han, G; Jia, L.X.; Li, D.; Prestemon, S. O.; Virostek, S.P.

    2008-01-01

    The RF coupling coil (RFCC) module of MICE is where muons that have been cooled within the MICE absorber focus (AFC) modules are re-accelerated to their original longitudinal momentum. The RFCC module consists of four 201.25 MHz RF cavities in a 1.4 meter diameter vacuum vessel. The muons are kept within the RF cavities by the magnetic field generated by a superconducting coupling solenoid that goes around the RF cavities. The coupling solenoid will be cooled using a pair of 4 K pulse tu...

  19. CO2-laser--produced plasma columns in a solenoidal magnetic field

    A 1-GW CO2 laser pulse has been used to produce extended column breakdown of hydrogen at low pressure in a 20-cm-long solenoid. Magnetic fields of up to 110 kG were used to inhibit radial losses of the plasma column. A differential pumping scheme was devised to prevent formation of an opaque absorption wave travelling out of the solenoid back toward the focusing lens. Target burns give direct evidence for trapped laser beam propagation along the plasma column

  20. 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. PMID:26931973

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

    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

  4. 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.

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

    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. The superconducting solenoid magnets for MICE

    Green, Michael A.

    2002-12-22

    The Muon Ionization Cooling Experiment (MICE) is a channel of superconducting solenoid magnets. The magnets in MICE are around the RF cavities, absorbers (liquid or solid) and the primary particle detectors [1], [2]. The MICE superconducting solenoid system consists of eighteen coils that are grouped in three types of magnet assemblies. The cooling channel consists of two complete cell of an SFOFO cooling channel. Each cell consists of a focusing coil pair around an absorber and a coupling coil around a RF cavity that re-accelerates the muons to their original momentum. At the ends of the experiment are uniform field solenoids for the particle detectors and a set of matching coils used to match the muon beam to the cooling cells. Three absorbers are used instead of two in order to shield the detectors from dark currents generated by the RF cavities at high operating acceleration gradients.

  9. 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].

  10. Superconducting solenoids for nuclear physics at Orsay

    Two systems using large superconducting solenoids are described. The first, SOLENO, is composed of two magnets (3T, 600 KJ each) and will replace a standard triplet of magnetic lenses; for the moment only the first magnet has gone into operation. The second system, a 5T solenoid, CRYEBIS II, is built in duplicate and will be used on heavy ion sources: one for our laboratory and the other one for the Research Institute of Physics/STOCKHOLM (Sweden). This system employs a superconducting switch to short-circuit the current on the magnet

  11. On tame embeddings of solenoids into 3-space

    Jiang, Boju; Wang, Shicheng; Zheng, Hao; Zhou, Qing

    2006-01-01

    Solenoids are ``inverse limits'' of the circle, and the classical knot theory is the theory of tame embeddings of the circle into the 3-space. We give some general study, including certain classification results, of tame embeddings of solenoids into the 3-space as the ``inverse limits'' of the tame embeddings of the circle. Some applications are discussed. In particular, there are ``tamely'' embedded solenoids $\\Sigma\\subset \\R^3$ which are strictly achiral. Since solenoids are non-planar, th...

  12. Fusion--fission hybrid reactors based on the laser solenoid

    Fusion-fission reactors, based on the laser solenoid concept, can be much smaller in scale than their pure fusion counterparts, with moderate first-wall loading and rapid breeding capabilities (1 to 3 tonnes/yr), and can be designed successfully on the basis of classical plasma transport properties and free-streaming end-loss. Preliminary design information is presented for such systems, including the first wall, pulse coil, blanket, superconductors, laser optics, and power supplies, accounting for the desired reactor performance and other physics and engineering constraints. Self-consistent point designs for first and second generation reactors are discussed which illustrate the reactor size, performance, component parameters, and the level of technological development required

  13. A Sensorless Method for Detecting Spool Position in Solenoid Actuators

    I. Dülk

    2013-06-01

    Full Text Available A method is developed to estimate the position of the moving part in a solenoid actuator. We superpose a sinusoidal component onto the base duty ratio of the drive PWM (Pulse Width Modulation, thus, a scan signal is generated which is used to first identify, then to “measure” the system during actuation. A model of the actuator device is derived from experimental analyses and the effects of e.g. scan signal frequency and supply voltage are studied. External force disturbances, which may be present in flow control applications, are also considered and an algorithm is provided for its compensation in position estimation, thus, force estimation is realized as well. The hardware requirements are low which makes the presented method suitable for cost effective embedded applications. Experimental results are also provided.

  14. 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...

  15. 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...

  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. Efficacy of magnetic resonance imaging at 3 T compared with 1.5 T in small pituitary tumors for stereotactic radiosurgery planning

    The objective of this study was to determine the value of high-field magnetic resonance imaging and to clarify the characteristics of each image among three-dimensional gradient echo (3D-GRE), two-dimensional spin echo (2D-SE) and inversion recovery (2D-IR) sequences used as contrast-enhanced T1-weighted images for stereotactic irradiation treatment planning of sellar lesions. Pulse sequences of 2D-SE and 3D-spoiled gradient recalled acquisition in the steady state (3D-SPGR) using GRE at 1.5 T and 2D-IR and 3D-fast SPGR (3D-FSPGR) at 3 T after injection of contrast material were acquired for 14 small pituitary tumors. As quantitative methods, signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were evaluated using a region-of-interest analysis. There was no significant difference in SNR between 1.5-T SPGR and 3-T FSPGR, while 3-T IR was superior to 1.5-T SE. The 2D-SE and -IR provided significantly better CNR than 3D-GRE between tumor and normal structures. Three Tesla was found to be superior to 1.5 T in distinguishing tumors from the normal sellar structure. Optimal dose planning will utilize each advantage of imaging; 3D-GRE allows high-resolution acquisition and 2D-SE and -IR can offer better tissue contrast. (author)

  18. ATLAS superconducting solenoid on-surface test

    Ruber, Roger J M Y; Doi, Y; Haruyama, T; Haug, F; ten Kate, H H J; Kawai, M; Kondo, T; Kondo, Y; Makida, Y; Mizumaki, S; Olesen, G; Pavlov, O V; Pezzetti, M; Pirotte, O; Sbrissa, E; Yamamoto, A

    2005-01-01

    The ATLAS detector is presently under construction as one of the five LHC experiment set-ups. It relies on a sophisticated magnet system for the momentum measurement of charged particle tracks. The superconducting solenoid is at the center of the detector, the magnet system part nearest to the proton-proton collision point. It is designed for a 2 Tesla strong axial magnetic field at the collision point, while its thin-walled construction of 0.66 radiation lengths avoids degradation of energy measurements in the outer calorimeters. The solenoid and calorimeter have been integrated in their common cryostat, cooled down and tested on-surface. We review the on-surface set-up and report the performance test results.

  19. Pulsable superconducting 28 kJoules-solenoid

    The construction and test of a pulsable superconducting solenoid magnet ('PUSSY') is described. The magnet has a cold bore of 80 mm diameter, and it reached a central field of 4.75 T after little training in the first run. The field homogeneity is 0.1% in 30 mm dsv and 1% in 60 mm dsv. The pecularities of this solenoid are the fully insulated braid conductor, consisting of 32 multifilament wires with 206 NbTi filaments each, and the application of copper heat drains for the cooling of the magnet windings. The magnet reached a rate of field change of 2 T/s or 630 A/s without significant degradation with respect to dc operation. (orig.)

  20. Comparison of Standard 1.5 T vs. 3 T Optimized Protocols in Patients Treated with Glatiramer Acetate. A Serial MRI Pilot Study

    Bianca Weinstock-Guttman

    2012-05-01

    Full Text Available This study explored the effect of glatiramer acetate (GA, 20 mg on lesion activity using the 1.5 T standard MRI protocol (single dose gadolinium [Gd] and 5-min delay or optimized 3 T protocol (triple dose of Gd, 20-min delay and application of an off-resonance saturated magnetization transfer pulse. A 15-month, phase IV, open-label, single-blinded, prospective, observational study included 12 patients with relapsing-remitting multiple sclerosis who underwent serial MRI scans (Days −45, −20, 0; the minus ign indicates the number of days before GA treatment; and on Days 30, 60, 90, 120, 150, 180, 270 and 360 during GA treatment on 1.5 T and 3 T protocols. Cumulative number and volume of Gd enhancing (Gd-E and T2 lesions were calculated. At Days −45 and 0, there were higher number (p < 0.01 and volume (p < 0.05 of Gd-E lesions on 3 T optimized compared to 1.5 T standard protocol. However, at 180 and 360 days of the study, no significant differences in total and cumulative number of new Gd-E and T 2 lesions were found between the two protocols. Compared to pre-treatment period, at Days 180 and 360 a significantly greater decrease in the cumulative number of Gd-E lesions (p = 0.03 and 0.021, respectively was found using the 3 T vs. the 1.5 T protocol (p = NS for both time points. This MRI mechanistic study suggests that GA may exert a greater effect on decreasing lesion activity as measured on 3 T optimized compared to 1.5 T standard protocol.

  1. Biggest superconducting solenoid magnet in China

    2006-01-01

    @@ At 8:00am, Sept. 19, the magnetic field of supercon ducting nagnet at the BESⅢ, an upgrade of Beijing Spectrometer, reached 1.0T. The current intensity reached 3,368A, and the energy stored by the solenoid reached 10MJ. Tests showed that the designed requirements had been fully met, which constitutes an important milestone for the BEPC Upgrade now underway at the CAS Institute of High Energy Physic (IHEP).

  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. Focusing solenoids for the MICE cooling channel

    This report describes a design for focusing solenoids for the low beta sections for the proposed Muon Ionization Cooling Experiment (MICE). There are three focusing solenoid pairs that will be around the muon absorbers for MICE. The two solenoid coils have an inside diameter of 510 mm, a length of 180 mm, and a thickness of 100 mm. A distance of 260 mm separates the two coils in the pair. The coils are designed to operate at opposite polarity, in order to create a gradient field in the low beta sections of the MICE cooling channel. As result, the force pushing the coil pair apart approaches 270 metric tons when the coils operate close to the short sample current for the superconductor. The forces between the coils will be carried by a support structure that is both on the inside and the outside the coils. During some modes of operation for MICE, the coils may operate at the same polarity, which means that the force between the coils pushes them together. The focusing magnet must be designed for both modes of operation. This support structure for the coils will be part of the focusing magnet quench protection system

  4. Development of a 15 T $Nb_3Sn$ Accelerator Dipole Demonstrator at Fermilab

    Novitski, I. [Fermilab; Andreev, N. [Fermilab; Barzi, E. [Fermilab; Carmichael, J. [Fermilab; Kashikhin, V. V. [Fermilab; Turrion, D. [Fermilab; Yu, M. [Fermilab; Zlobin, A. V. [Fermilab

    2015-01-01

    100 TeV scale Hadron Collider (HC) with a nominal operation field of at least 15 T is being considered for the post-LHC era, which requires using the $Nb_3Sn$ technology. Practical demonstration of this field level in an accelerator-quality magnet and substantial reduction of the magnet costs are the key conditions for realization of such a machine. FNAL has started the development of a 15 T Nb3Sn dipole demonstrator for a 100 TeV scale HC. The magnet design is based on 4-layer shell type coils, graded between the inner and outer layers to maximize the performance and reduce the cost. The experience gained during the Nb3Sn magnet R&D is applied to different aspects of the magnet design. This paper describes the magnetic and structural designs and parameters of the 15 T Nb3Sn dipole and the steps towards the demonstration model fabrication.

  5. Infratentorial brain maturation: a comparison of MRI at 0.5 and 1.5 T

    Our purpose was to establish parameters for normal infratentorial brain maturation at 0.5 and 1.5 T and to evaluate the field strength criteria for the assessment of infratentorial brain maturation with MRI. We examined 27 children with normal psychomotor development (3 days to 24 months) with a 1.5 T system and 22 (4 days to 29 months) with a 0.5 T system; standard T2-weighted spin-echo sequences (TR/TE 2 500/90 ms at 1.5 T and TR/TE 2 200/90 ms at 0.5 T) were obtained. The signal intensity of infratentorial anatomical structures compared to their surroundings was classified as high, isointense or low by three neuroradiologists. For anatomical structures with age-related contrast changes, the time of these changes was determined statistically for the 0.5 T and 1.5 T system independently. The delineation of the structures without age-related contrast changes at the two field strengths was compared using a χ 2 test. Age-related contrast changed were found in the same anatomical structures (''marker sites'') at 0.5 and 1.5 T. Generally, these changes were apparent in larger structures (pons, middle cerebellar peduncles, medulla, cerebellar folia, red nuclei, cerebral peduncles), with only slight field-strength-dependent differences in the time of the contrast changes. Contrast changes from high to isointense signal were observed slightly earlier at 0.5 T and changes from isointense to low signal slightly later at 0.5 T. The delineation of the smaller anatomical structures was significantly better at 1.5 T but these structures did not show age-related contrast changes. The differences in the assessment of infratentorial brian maturation between 0.5 and 1.5 T can be attributed to a lower signal-to-noise ratio at lower magnetic field strengths. These differences do not complicate temporal classification of the stage of infratentorial brain maturation using the same ''marker sites'' and the same temporal criteria at 0.5 or 1.5 T. (orig.). With 4 figs., 2 tabs

  6. Infratentorial brain maturation: a comparison of MRI at 0.5 and 1.5 T

    Hittmair, K. [MR Institute, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Kramer, J. [MR Institute, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Rand, T. [Department of Diagnostic Radiology, University of Vienna, Vienna (Austria); Bernert, G. [Department of Paediatrics, University of Vienna, Vienna (Austria); Wimberger, D. [Department of Diagnostic Radiology, University of Vienna, Vienna (Austria)

    1996-05-01

    Our purpose was to establish parameters for normal infratentorial brain maturation at 0.5 and 1.5 T and to evaluate the field strength criteria for the assessment of infratentorial brain maturation with MRI. We examined 27 children with normal psychomotor development (3 days to 24 months) with a 1.5 T system and 22 (4 days to 29 months) with a 0.5 T system; standard T2-weighted spin-echo sequences (TR/TE 2 500/90 ms at 1.5 T and TR/TE 2 200/90 ms at 0.5 T) were obtained. The signal intensity of infratentorial anatomical structures compared to their surroundings was classified as high, isointense or low by three neuroradiologists. For anatomical structures with age-related contrast changes, the time of these changes was determined statistically for the 0.5 T and 1.5 T system independently. The delineation of the structures without age-related contrast changes at the two field strengths was compared using a {chi} {sup 2} test. Age-related contrast changed were found in the same anatomical structures (``marker sites``) at 0.5 and 1.5 T. Generally, these changes were apparent in larger structures (pons, middle cerebellar peduncles, medulla, cerebellar folia, red nuclei, cerebral peduncles), with only slight field-strength-dependent differences in the time of the contrast changes. Contrast changes from high to isointense signal were observed slightly earlier at 0.5 T and changes from isointense to low signal slightly later at 0.5 T. The delineation of the smaller anatomical structures was significantly better at 1.5 T but these structures did not show age-related contrast changes. The differences in the assessment of infratentorial brian maturation between 0.5 and 1.5 T can be attributed to a lower signal-to-noise ratio at lower magnetic field strengths. These differences do not complicate temporal classification of the stage of infratentorial brain maturation using the same ``marker sites`` and the same temporal criteria at 0.5 or 1.5 T. (orig.). With 4 figs., 2 tabs.

  7. Progress of the ITER Central Solenoid Model Coil Program

    The world s largest pulsed superconducting coil was successfully tested by charging up to 13 T and 46 kA with a stored energy of 640 MJ. The ITER Central Solenoid (CS) Model Coil and CS Insert Coil were developed and fabricated through an international collaboration and their cool down and charging tests were successfully carried out by international test and operation teams. In pulsed charging tests, where the original goal was 0.4T/s up to 13T, the CS Model Coil and the CS Insert Coil achieved ramp rates of 0.6T/s and 1.2T/s up to 13T, respectively. In addition, the CS Insert Coil was charged and discharged 10,003 times in the 13-T background field of the CS Model Coil and no degradation of the operational temperature margin directly coming from this cyclic operation was observed. These test results fulfilled all the goals of CS Model Coil development by confirming the validity of the engineering design and demonstrating that we are now ready to construct the ITER coils with confidence. (author)

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

    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.

  9. Magnetic and Structural Design of a 15 T $Nb_3Sn$ Accelerator Depole Model

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

    2015-01-01

    Hadron Colliders (HC) are the most powerful discovery tools in modern high energy physics. A 100 TeV scale HC with a nominal operation field of at least 15 T is being considered for the post-LHC era. The choice of a 15 T nominal field requires using the Nb3Sn technology. Practical demonstration of this field level in an accelerator-quality magnet and substantial reduction of the magnet costs are the key conditions for realization of such a machine. FNAL has started the development of a 15 T $Nb_{3}Sn$ dipole demonstrator for a 100 TeV scale HC. The magnet design is based on 4-layer shell type coils, graded between the inner and outer layers to maximize the performance. The experience gained during the 11-T dipole R&D campaign is applied to different aspects of the magnet design. This paper describes the magnetic and structural designs and parameters of the 15 T $Nb_3Sn$ dipole and the steps towards the demonstration model.

  10. Magnetic and structural design of a 15 T Nb3Sn accelerator dipole model

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

    2015-12-01

    Hadron Colliders (HC) are the most powerful discovery tools in modern high energy physics. A 100 TeV scale HC with a nominal operation field of at least 15 T is being considered for the post-LHC era. The choice of a 15 T nominal field requires using the Nb3Sn technology. Practical demonstration of this field level in an accelerator-quality magnet and substantial reduction of the magnet costs are the key conditions for realization of such a machine. FNAL has started the development of a 15 T Nb3Sn dipole demonstrator for a 100 TeV scale HC. The magnet design is based on 4-layer shell type coils, graded between the inner and outer layers to maximize the performance. The experience gained during the 11-T dipole R&D campaign is applied to different aspects of the magnet design. This paper describes the magnetic and structural designs and parameters of the 15 T Nb3Sn dipole and the steps towards the demonstration model.

  11. Survey of the laser-solenoid fusion reactor

    This report surveys the prospects for a laser-solenoid fusion reactor. A sample reactor and scaling laws are used to describe the concept's characteristics. Experimental results are reviewed, and the laser and magnet technologies that undergird the laser-solenoid concept are analyzed. Finally, a systems analysis of fusion power reactors is given, including a discussion of direct conversion and fusion-fission effects, to ascertain the system attributes of the laser-solenoid configuration

  12. Tolerance Studies of the Mu2e Solenoid System

    Lopes, M. L. [Fermilab; Ambrosio, G. [Fermilab; Buehler, M. [Fermilab; Coleman, R. [Fermilab; Evbota, D. [Fermilab; Feher, S. [Fermilab; Kashikhin, V. V. [Fermilab; Lamm, M. [Fermilab; Miller, J. [Boston U.; Moretti, G. [Fermilab; Ostojic, R. [CERN; Page, T. [Fermilab; Popp, J. [York Coll., N.Y.; Tartaglia, M. [Fermilab

    2014-01-01

    The muon-to-electron conversion experiment at Fermilab is designed to explore charged lepton flavor violation. It is composed of three large superconducting solenoids, namely, the production solenoid, the transport solenoid, and the detector solenoid. Each subsystem has a set of field requirements. Tolerance sensitivity studies of the magnet system were performed with the objective of demonstrating that the present magnet design meets all the field requirements. Systematic and random errors were considered on the position and alignment of the coils. The study helps to identify the critical sources of errors and which are translated to coil manufacturing and mechanical support tolerances.

  13. Numerical modeling of the laser heated solenoid

    A numerical model of the interaction of laser radiation with the magnetically confined plasma in an infinitive solenoid was given. An approximate solution which includes the balance of total pressure instead of momentum equation was also developed. Thus, the time step in computing is not bounded by the characteristics given by the Alfven speed. This approximation approach makes the efficient computing of this problem possible. The results of the approximate solution agree very well with those of the exact solution. They have the same final steady state solution

  14. Quality Control of MRS on GE 1.5T MR%GE 1.5T MR扫描仪的MRS质量监测

    窦砚彬; 王霄英; 蒋学祥

    2006-01-01

    @@ 磁共振波谱分析(magnetic resonance spectroscopy,MRS)检查对MR设备的性能要求很高,扫描过程中的各种硬件性能改变可能造成MRS检查结果的误差.尤其是同一患者在不同时间进行MRS检查时,进行前后结果的半定量比较时,必须要除外扫描设备的性能偏差对检查结果的影响.本文介绍了对GE1.5T MR扫描仪的MRS扫描质量进行监测的简单方法.

  15. Measurement of the ATLAS solenoid magnetic field

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

    2008-01-01

    ATLAS is a general purpose detector designed to explore a wide range of physics at the Large Hadron Collider. At the centre of ATLAS is a tracking detector in a 2 T solenoidal magnetic field. This paper describes the machine built to map the field, the data analysis methods, the final results, and their estimated uncertainties. The remotely controlled mapping machine used pneumatic motors with feedback from optical encoders to scan an array of Hall probes over the field volume and log data at more than 20 000 points in a few hours. The data were analysed, making full use of the physical constraints on the field and of our knowledge of the solenoid coil geometry. After a series of small corrections derived from the data itself, the resulting maps were fitted with a function obeying Maxwell's equations. The fit residuals had an r.m.s. less than 0.5 mT and the systematic error on the measurement of track sagitta due to the field uncertainty was estimated to be in the range 0.02 % to 0.12 % depending on the track...

  16. 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...

  17. 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.

  18. Design of permanent magnetic solenoids for REGAE

    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.

  19. Report of the large solenoid detector group

    Hanson, G.G.; Mori, S.; Pondrom, L.G.; Williams, H.H.; Barnett, B.; Barnes, V.; Cashmore, R.; Chiba, M.; DeSalvo, R.; Devlin, T.

    1987-09-01

    This report presents a conceptual design of a large solenoid for studying physics at the SSC. The parameters and nature of the detector have been chosen based on present estimates of what is required to allow the study of heavy quarks, supersymmetry, heavy Higgs particles, WW scattering at large invariant masses, new W and Z bosons, and very large momentum transfer parton-parton scattering. Simply stated, the goal is to obtain optimum detection and identification of electrons, muons, neutrinos, jets, W's and Z's over a large rapidity region. The primary region of interest extends over +-3 units of rapidity, although the calorimetry must extend to +-5.5 units if optimal missing energy resolution is to be obtained. A magnetic field was incorporated because of the importance of identifying the signs of the charges for both electrons and muons and because of the added possibility of identifying tau leptons and secondary vertices. In addition, the existence of a magnetic field may prove useful for studying new physics processes about which we currently have no knowledge. Since hermeticity of the calorimetry is extremely important, the entire central and endcap calorimeters were located inside the solenoid. This does not at the moment seem to produce significant problems (although many issues remain to be resolved) and in fact leads to a very effective muon detector in the central region.

  20. Report of the large solenoid detector group

    This report presents a conceptual design of a large solenoid for studying physics at the SSC. The parameters and nature of the detector have been chosen based on present estimates of what is required to allow the study of heavy quarks, supersymmetry, heavy Higgs particles, WW scattering at large invariant masses, new W and Z bosons, and very large momentum transfer parton-parton scattering. Simply stated, the goal is to obtain optimum detection and identification of electrons, muons, neutrinos, jets, W's and Z's over a large rapidity region. The primary region of interest extends over +-3 units of rapidity, although the calorimetry must extend to +-5.5 units if optimal missing energy resolution is to be obtained. A magnetic field was incorporated because of the importance of identifying the signs of the charges for both electrons and muons and because of the added possibility of identifying tau leptons and secondary vertices. In addition, the existence of a magnetic field may prove useful for studying new physics processes about which we currently have no knowledge. Since hermeticity of the calorimetry is extremely important, the entire central and endcap calorimeters were located inside the solenoid. This does not at the moment seem to produce significant problems (although many issues remain to be resolved) and in fact leads to a very effective muon detector in the central region

  1. Clinical advantages of 3.0 T MRI over 1.5 T

    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

  2. Multiple adrenal masses: MRI tissue differentiation of pheochromocytoma and adenoma at 1.5 T

    We present the case of 38-year-old hypertensive patient with bilateral adrenal masses and with clinical and biochemical suspicion of pheochromocytoma. Magnetic resonance imaging at 1.5 T established correct diagnosis of coexisting adrenal pheochromocytoma and adenoma (nonhyperfunctioning). The case supports the usefulness of MRI for definitive evaluation of bilateral adrenal masses in patients with suspicion of pheochromocytoma. (orig.). With 2 figs

  3. 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.

  4. Quantification of dextrose in model solution by 1H MR spectroscopy at 1.5T

    To evaluate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) using a 1.5T magnetic resonance (MR) imager for quantification of the contents of model solutions. We prepared model solutions of dextrose +water and dextrose +water + ethanol at dextrose concentrations of 0.01% to 50% and 0.01% to 20%, respectively. Using these solutions and a 1.5T MR imager together with a high-resolution nuclear magnetic resonance (NMR) spectroscope, we calculated the ratios of dextrose to water peak, (dextrose +ethanol) to water peak, and (dextrose + ethanol) to ethanol peak, as seen on MR and NMR spectra, analysing the relationships between dextrose concentration and the ratios of peaks, and between the ratios of the peaks seen on MR spectra and those seen on NMR spectra. Changes in the ratios between dextrose concentration and dextrose to water peak, (dextrose + ethanol) to water peak and (dextrose + ethanol) to ethanol peak, as seen on MR spectra, were statistically significant, and there was good linear regression. There was also close correlation between the ratios of the observed on MR and NMR spectra. The results depict the quantification of dextrose concentration according to the ratios of spectral peaks obtained by proton MRS at 1.5T. Using proton MRS at 1.5T, and on the basis of the ratios of spectcal peaks, it was possible to quantify the concentration of dextrose in model solutions of dextrose + water and dextrose + water+ ethanol. The results of this study suggest that for quantifying the contents of biofluids, the use of low-tesla 1H-MRS is feasible

  5. Plasma confinement apparatus using solenoidal and mirror coils

    A plasma confinement apparatus is described, wherein multiple magnetic mirror cells are linked by magnetic field lines inside of a solenoid with the mirroring regions for adjacent magnetic mirror cells each formed by a separate mirror coil inside of the solenoid. The magnetic mirror cells may be field reversed

  6. 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...

  7. ITER central solenoid model coil impregnation optimization

    Schutz, J. B.; Munshi, N. A.; Smith, K. B.

    The success of the vacuum-pressure impregnation of the International Thermonuclear Experimental Reactor central solenoid is critical to success of the magnet system. Analysis of fluid flow through a fabric bed is extremely complicated, and complete analytical solutions are not available, but semiempirical methods can be adapted to model these flows. Several of these models were evaluated to predict the impregnation characteristics of a liquid resin through a mat of reinforcing glass fabric, and an experiment was performed to validate these models. The effects of applied pressure differential, glass fibre volume fraction, resin viscosity and impregnation time were examined analytically. From the results of this optimization, it is apparent that use of elevated processing temperature resin systems offer significant advantages in large scale impregnation due to their lower viscosity and longer working life, and they may be essential for large scale impregnations.

  8. ITER CENTRAL SOLENOID COIL INSULATION QUALIFICATION

    Martovetsky, N N; Mann, T L; Miller, J R; Freudenberg, K D; Reed, R P; Walsh, R P; McColskey, J D; Evans, D

    2009-06-11

    An insulation system for ITER Central Solenoid must have sufficiently high electrical and structural strength. Design efforts to bring stresses in the turn and layer insulation within allowables failed. It turned out to be impossible to eliminate high local tensile stresses in the winding pack. When high local stresses can not be designed out, the qualification procedure requires verification of the acceptable structural and electrical strength by testing. We built two 4 x 4 arrays of the conductor jacket with two options of the CS insulation and subjected the arrays to 1.2 million compressive cycles at 60 MPa and at 76 K. Such conditions simulated stresses in the CS insulation. We performed voltage withstand tests and after end of cycling we measured the breakdown voltages between in the arrays. After that we dissectioned the arrays and studied micro cracks in the insulation. We report details of the specimens preparation, test procedures and test results.

  9. Concept design of the CFETR central solenoid

    Highlights: • Main concept design work including coil's geometry, superconductor and support structure has been carried out. • The maximum magnetic field of CS coil is 11.9 T which is calculated by the coils’ operation current based on plasma equilibrium configuration. • The stray field in plasma area is less than 20 Gs under the CS coils’ operation currents designed for the plasma-heating phase. - Abstract: China Fusion Engineering Test Reactor (CFETR) superconducting tokamak is a national scientific research project of China with major and minor radius is 5.7 m and 1.6 m respectively. The magnetic field at the center of plasma with radius as R = 5.7 m is set to be 5.0 T. The major objective of the project is to build a fusion engineering tokamak reactor with fusion power in the range of 50–200 MW and should be self-sufficient by blanket. Six central solenoid coils of CFETR with same structure are made of Nb3Sn superconductor. Besides, the stray field in plasma area should be less than 20 Gs with the operation current of CS coils for plasma heating phase. The maximum magnetic field of CS coil is 11.9 T. It is calculated by the coils’ operation current based on plasma equilibrium configuration. The central solenoid needs to have enough stability margin under the condition of high magnetic field and strain. This paper discusses the design parameters, electromagnetic distribution, structure and stability analysis of the CS superconducting magnet for CFETR

  10. Endloss from a slender high-beta plasma column contained in a linear solenoid

    Linear high-beta devices are potential fusion reactors in which a long narrow plasma is contained laterally by a vacuum magnetic field of a straight pulsed solenoid and is allowed to stream freely out at the magnet ends. The plasma is composed of a stationary central region plasma, and streaming plasma regions at each end. The present analysis determines a confinement time based on the lifetime of the central stationary plasma. This lifetime is a hybrid related to the acoustic transit time and cross-field diffusion time and differs significantly from existing theories. Its relevance to future plasma experiments and fusion reactor studies is given. (U.K.)

  11. Laser heating and magnetic compression of plasma in a fast solenoid

    A low-β plasma column a few mm in diameter by 22 cm in length is heated by an axially directed CO2 laser to a high-β state in a fast rising solenoidal field. Successful heating depends on proper timing between the laser pulse and rising field. Typical conditions attained are a line energy density of 6 J/cm, T-barapprox. =40 eV, and n/sub e/approx. =3 x 1017e-/cm3, with conditions quite uniform along the length. The heating suppresses instabilities which appear under certain conditions in the non-laser-heated case

  12. 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.

  13. The Mice Focusing Solenoids and their Cooling System

    This report describes the focusing solenoid for the proposed Muon Ionization Cooling Experiment (MICE) [1]. The focusing solenoid consists of a pair of superconducting solenoids that are on a common bobbin. The two coils, which have separate leads, may be operated in the same polarity or at opposite polarity. This report discusses the superconducting magnet design and the cryostat design for the MICE focusing module. Also discussed is how this superconducting magnet can be integrated with a pair of small 4.2 K coolers

  14. 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.

  15. Design report for a cryostable 3m diameter superconducting solenoid for the Fermilab Collider Detector Facility

    The Fermilab Collider Detector Facility (CDF) is a large detector system designed td study anti pp collisions at very high center of mass energies. The central detector for the CDF employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 4 m long and 3 m in diameter. To provide the desired Δp/sub T//p/sub T/ less than or equal to 15% at 50 GeV/c using drift chambers with approx. 200μ resolution the field inside this volume should be 1.5 T. This field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 106 A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe a design for a cryostable superconducting solenoid intended to meet the requirements of the Fermilab ies TDF

  16. The electromagnetic calorimeter for the solenoidal tracker at RHIC

    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

  17. 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...

  18. Cryogenic tests of the g-2 superconducting solenoid magnet system

    The g-2 muon storage ring magnet system consists of four large superconducting solenoids that are up to 15.1 m in diameter. The g-2 superconducting solenoids and a superconducting inflector dipole will be cooled using forced two-phase helium in tubes. The forced two-phase helium cooling will be provided from the J-T circuit of a refrigerator that is capable of delivering 625 W at 4.5 K. The two-phase helium flows from the refrigerator J-T circuit through a heat exchanger in a storage dewar that acts as a phase separator for helium returning from the magnets. The use of a heat exchanger in the storage dewar reduces the pressure drop in the magnet flow circuit, eliminates most two phase flow oscillations, and it permits the magnets to operate at variable thermal loads using the liquid in the storage dewar as a buffer. The g-2 magnet cooling system will consist of three parallel two-phase helium flow circuits that provide cooling to the following components: (1) the four large superconducting solenoids, (2) the current interconnects between the solenoids and the solenoid gas cooled electrical leads, and (3) the inflector dipole and its gas cooled electrical leads. This report describes a cryogenic test of the two 15.1 meter diameter superconducting solenoids using two-phase helium from a dewar. The report describes the cool down procedure for the 3.5 ton outer solenoid magnet system using liquid nitrogen and two-phase helium. Low current operation of the outer solenoids is discussed

  19. Cryogenic tests of the g-2 superconducting solenoid magnet system

    The g-2 muon storage ring magnet system consists of four large superconducting solenoids that are up to 15.1 m in diameter. The g-2 superconducting solenoids and a superconducting inflector dipole will be cooled using forced two-phase helium in tubes. The forced two-phase helium cooling will be provided from the J-T circuit of a refrigerator that is capable of delivering 625 W at 4.5 K. The two-phase helium flows from the refrigerator J-T circuit through a heat exchanger in a storage dewar that acts as a phase separator for helium returning from the magnets. The use of a heat exchanger in the storage dewar reduces the pressure drop in the magnet flow circuit, eliminates most two phase flow oscillations, and it permits the magnets to operate at variable thermal loads using the liquid in the storage dewar as a buffer. The g-2 magnet cooling system will consist of three parallel two-phase helium flow circuits that provide cooling to the following components; (1) the four large superconducting solenoids, (2) the current interconnects between the solenoids and the solenoid gas cooled electrical leads, and (3) the inflector dipole and its gas cooled electrical leads. This report describes a cryogenic test of the two 15.1 meter diameter superconducting solenoids using two-phase helium from a dewar. The report describes the cool down procedure for the 3.5 ton outer solenoid magnet system using liquid nitrogen and two-phase helium. Low current operation of the outer solenoids is discussed

  20. 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...

  1. Cryogenic testing of the TPC superconducting solenoid

    Green, M. A.; Smits, R. G.; Taylor, J. D.; Vanslyke, V.; Barrera, F.; Petersen, H.; Rago, C. E.; Rinta, R. I.; Talaska, D.; Watt, R. D.

    1983-06-01

    This report describes the results of a series of tests on the TPC superconducting magnet cryogenic system which occurred during the winter and spring of 1983. The tests occurred at interaction region 2 of the PEP colliding beam facility at the Stanford Linear Accelerator Center (SLAC). The TPC Magnet Cryogenic System which was tested includes the following major components: a remote helium compressor with a full flow liquid nitrogen purification station, 400 meters of high pressure supply and low pressure return lines; and locally a CTi Model 2800 refrigerator with two Sulzer gas bearing turbines, the TPC magnet control dewar, 70 meters of transfer lines, and the TPC thin superconducting solenoid magnet. In addition, there is a conditioner (liquid nitrogen heat exchangers and gas heaters) system for cooldown and warmup of the magnet. This report describes the local cryogenic system and describes the various steps in the cooldown and operation of the TPC magnet. The tests were successful in that they showed that the TPC magnet could be cooled down in 24 hours and the magnet could be operated on the refrigerator or a helium pump with adequate cooling margin.

  2. 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.)

  3. Analysis of temperature field of direct action solenoid valve

    Background: Hydraulic Control Rod Drive Technology (HCRDT) is a newly invented patent and Institute of Nuclear and New Energy Technology Tsinghua University owns HCRDT's independent intellectual property rights. Purpose: 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. The performance of the coil affects the service behavior of the solenoid valve, so the thermal performance of the coil is researched. Methods: The temperature field of the coil of the direct action solenoid valve was analyzed using the ANSYS software with various currents, the results of which were validated by experiments. Results: The result shows that the temperature of the coil of the solenoid valve increases with the current increasing firstly. Second, the temperature of the inner wall of the coil is higher than that of the exterior wall. The temperature of the middle coil is higher than that of the edge of the coil. Third, the coefficient of thermal conductivity of the coil is obtained. Fourth, the highest temperature of the coil is under the limiting temperature. Furthermore, the comparison of the temperature of the coil achieved by calculation with the one achieved by experiment under different condition shows that the calculation results are rational if the experiment errors are considered. Conclusions: The results can be provided for the parameter design of the solenoid valve. (authors)

  4. 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.

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

    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. (topical review)

  6. Experimental study of a laser-heated solenoid

    An experimental investigation was made of the interaction of an intense CO2 laser beam with a column of initially uv-ionized hydrogen immersed in a steady magnetic field of up to 100 kG. Under the intense laser radiation, the gas becomes ionized and heated to temperatures as high as 150 eV (1.6 x 1060K). The primary purpose of the investigation was to determine the properties of the dense, hot plasma formed in this manner. Time and space resolved measurements of the plasma electron density were made using holographic interferometry along the axis and Mach--Zehnder interferometry across the column. The temperature was determined by measuring the decay rate of a line from CV in the quartz uv. These measurements were supplemented by streak photography to provide data on the development of the luminosity of the plasma column, radially and axially, as a function of time. From these various diagnostic techniques, it was possible to determine that a density minimum is formed on-axis within a few tens of nanoseconds after initiation of the laser pulse. This effectively produces a light pipe which traps the beam, and suggests that long columns can be formed by laser irradiation. The beam energy was efficiently absorbed and plasma loss rates appeared to be those expected from classical MHD modelling. While a completely unambiguous answer as to the mode of laser discharge propagation occurring in the experiment was not obtained, the bulk of the evidence suggests a ''bleaching wave'' rather than a laser driven detonator. In summary, the experiment was successful in demonstrating the creation of dense, slender columns by laser breakdown, in support of the ''laser-heated solenoid'' fusion concept

  7. A 4.7 tesla meter solenoid for a partial Siberian Snake

    The authors describe the engineering design of a 4.7 T-m solenoid magnet which will be installed at the Brookhaven National Laboratory AGS for a partial Siberian Snake Experiment which is an interlaboratory collaboration. The magnet has an overall length of 2.5 m, a clear bore of 15 cm and operates at a peak field of 2 T. It is pulsed at 3 second intervals with a peak current of 9,500 A dc driven from a 150 V power supply. The construction uses conventional hollow copper coils but the return flux yokes are made from 1/8 inch plates bolted together. On assembly the flux yokes and endplates are clamped tightly to the coil to prevent any movement during the current pulse. The fabrication experience and test data will be presented. The magnet was installed in the summer of 1993

  8. A 4.7 tesla metre solenoid for a partial Siberian snake

    We describe the engineering design of a 4.7 T-m solenoid magnet which will be installed at the Brookhaven National Laboratory AGS for a partial Siberian Snake Experiment which is an interlaboratory collaboration. The magnet has an overall length of 2.5 m, a clear bore of 15 cm and operates at a peak field of 2 T. It is pulsed at 3 second intervals with a peak current of 9500 A dc driven from a 150 V power supply. The construction uses conventional hollow copper coils but the return flux yokes are made from 1/8 inch plates bolted together. On assembly the flux yokes and endplates are clamped tightly to the coil to prevent any movement during the current pulse. The fabrication experience and test data will be presented. The magnet was installed in the summer of 1993. (author). 3 refs., 1 tab., 1 fig

  9. MR imaging (at 1.5 T) of the brachial plexus

    Brachial plexus pathology can at times be difficult to visualize on CT, relative to normal structures, even with the aid of intravenous contrast. MR images of this area routinely give excellent anatomic delineation, due to the marked contrast in signal between fat in the axillary fossa, muscle, and pathology. The authors studied 15 patients at 1.5 T, eight normal and seven abnormal, with visualization of the trunks and cords. Some of the positive cases included metastatic deposits, cervical rib, severe vascular ectasia, a postangiography hematoma, etc. The distinct signal of pathologic tissue compared with the distinct signals of normal structures and the ability to evaluate vascular patency make MR imaging ideally suited in the evaluation of this region without the need of intravenous contrast

  10. High-resolution MR imaging of the adult hip at 1.5 T

    The hip in human adults is a deep-seated joint space, and MR images of the hip often lack high spatial accuracy. This protocol uses an optimized MR technique providing a higher spatial resolution and a better assessment of the join space, articular cartilages, fibrocartilages, synovium, capsule, and surrounding structures. Twenty-six adult hips were imaged with a 1.5-T Signa magnet. The high-resolution protocol included (1) a 256 x 256 matrix; (2) a small field of view; (3) several types of surface coils; (4) various coil positions; (5) several degrees of hip flexion (0 degrees, 15 degrees, 30 degrees); (6) hip internal rotation of 0 degrees/20 degrees

  11. Design And Construction Of A 15 T, 120 MM Bore IR Quadrupole Magnet For LARP

    Pushing accelerator magnets beyond 10 T holds a promise of future upgrades to machines like the Large Hadron Collider (LHC) at CERN. Nb3Sn conductor is at the present time the only practical superconductor capable of generating fields beyond 10 T. In support of the LHC Phase-II upgrade, the US LHC Accelerator Research Program (LARP) is developing a large bore (120 mm) IR quadrupole (HQ) capable of reaching 15 T at its conductor peak field and a peak gradient of 219 T/m at 1.9 K. While exploring the magnet performance limits in terms of gradient, forces and stresses the 1 m long two-layer coil will demonstrate additional features such as alignment and accelerator field quality. In this paper we summarize the design and report on the magnet construction progress.

  12. Quantitation of glutamate in the brain by using MR proton spectroscopy at 1.5 T and 3 T

    Purpose: the influence of different magnetic field strengths on the quantification of glutamate was experimentally investigated by means of in vitro and in vivo 1H-MR spectroscopic measurements at 1.5 T and 3 T. Materials and methods: in vitro 1H-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-1H-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 SNRGlu, 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 %SDGlu < 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.)

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

    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

  14. The LASS [Larger Aperture Superconducting Solenoid] spectrometer

    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

  15. Solenoid-free startup experiments in DIII-D

    Leuer, J. A.; Cunningham, G.; Mueller, D.; Brooks, N. H.; Eidietis, N. W.; Humphreys, D. A.; Hyatt, A. W.; Jackson, G. L.; Lohr, J.; Politzer, P. A.; Pinsker, R. I.; Prater, R.; Taylor, P. L.; Walker, M. L.; Budny, R. V.; Gates, D. A.; Nagy, A.; Hahn, S.-H.; Oh, Y.-K.; Yoon, S.-W.; Yu, J. H.; Murakami, M.; Park, J. M.; Sontag, A. C.

    2011-06-01

    A series of DIII-D experiments was performed to investigate the potential for initiating plasma current using only poloidal field coils located outside the DIII-D central solenoid, i.e. 'solenoid-free'. Plasma current to 166 kA was achieved using 2-3 MW of electron cyclotron (EC) heating and was limited by coil and power supply constraints. Flux conversion to plasma current was similar to standard DIII-D startup with some degradation at higher plasma current associated with stray fields and vertical stability issues. In preliminary solenoid-free experiments, neutral beam (NB) current drive (CD) levels were small and attributed to reduced CD efficiency associated with low electron temperature produced by the low current, low confinement plasma. Lack of plasma radial position control also contributed to a reduction of NBCD. Similarly, ECCD was small owing to low plasma temperature and outside EC launch which is required in the solenoid-free scenario. Synergistic experiments were carried out using standard solenoid initiated plasmas in order to study noninductive CD in limited, Lmode plasmas, typical of that generated by solenoid-free startup. While substantial noninductive current can be driven, self-sustaining levels of noninductive current have not yet been achieved with our present six-source co-injection NB system combined with EC and fast wave systems. At low plasma current and high levels of localized EC heating, substantial MHD is generated and this was seen to severely limit plasma performance. Although further optimization is possible in the limited plasma regime, full noninductive, steady-state operation may require diverted plasma with H-mode quality confinement. Discharges obtained during the solenoid-free campaign are compared with results of previous DIII-D campaigns aimed at achieving a steady state, noninductive CD solution.

  16. In vivo characterisation of soft tissue tumours by 1.5-T proton MR spectroscopy

    Russo, F.; Mazzetti, S.; Grignani, G.; Rosa, G.De; Aglietta, M.; Anselmetti, G.C.; Stasi, M.; Regge, D. [Institute for Cancer Research and Treatment (IRCC), Candiolo, Torino (Italy)

    2012-05-15

    To determine whether proton magnetic resonance spectroscopy (1H-MRS) can help differentiate between benign and malignant soft tissue lesions, and to assess if there is a correlation between 1H-MRS data and the mitotic index. MR measurements were performed in 43 patients with soft tissue tumours >15 mm in diameter. Six cases were excluded for technical failure. Examinations were performed at 1.5 T using a single-voxel point resolved spectroscopy sequence (PRESS) with TR/TE = 2000/150 ms. The volume of interest was positioned within the lesion avoiding inclusion of necrotic regions. In all patients, a histological diagnosis was obtained and the corresponding mitotic index was also computed. 1H-MRS results and histopathological findings were compared using the chi-squared test and correlation coefficient. Choline was detected in 18/19 patients with malignant tumours and in 3/18 patients with benign lesions. The three benign lesions included one desmoid tumour, one ossificans myositis and one eccrine spiradenoma. Choline was not detected in 15 patients with benign lesions or in one patient with dermatofibrosarcoma protuberans. Resulting 1H-MRS sensitivity and specificity were 95% and 83% respectively. Absence of choline peak is highly predictive of benign tumours suggesting that 1H-MRS can help to differentiate malignant from benign tumours. (orig.)

  17. Craniopharyngiomas - the utility of contrast medium enhancement for MR imaging at 1.5 T

    To evaluate the efficacy of i.v. contrast medium administration in MR imaging at 1.5 T in patients with craniopharyngiomas, MR studies of 10 men and 6 women with pathologically proven craniopharyngiomas were made. The MR images were obtained as 3- to 5-mm-thick coronal (n=13) or axial (n=3) T1-weighted images (T1WI) prior to an following i.v. Gd-DTPA administration. Proton density-(PD) and T2-weighted images (T2WI) were also obtained. Conspicuity of tumor margins, cystic versus solid components, size, location and effect upon adjacent structures were separately characterized in all imaging sequences. In 6 patients contrast medium-enhanced T1WI, PD and T2WI demonstrated cystic tumor components not seen on unenhanced T1WI. There were significant differences (p<0.004) on 2-tailed Student's t-test comparing tumor conspicuity on contrast medium-enhanced T1WI with unenhanced T1WI, PD and T2WI. Optimal tumor delineation on MR imaging of patients with craniopharyngiomas justifies the use of i.v. contrast medium. (orig.)

  18. Angiographically occult vascular malformation of the brain: MR imaging at 1.5 T

    MR imaging was performed in nine patients with 12 angiographically occult arteriovenous malformations using a 1.5-T superconducting magnet; four additional patients were imaged using a 0.3-T system. All images were reviewed in conjunction with CT scans. The following observations were made. (1) Eleven of 14 supratentorial lesions were located at the junction of gray and white matter. (2) Exclusing acute hemorrhage, only two lesions displayed mild mass effect. (3) All lesions displayed central foci of high signal intensity, probably representing subacute hemorrhage. (4) All lesions but one showed a peripheral rim of low signal intensity which progressively lost signal with increasing T2 weighting. This most likely represents iron-containing hemosiderin deposition. (5) Lesions were best demonstrated with long repetition times and moderate T2 weighting (TR = 2,500 msec, TE = 25-100 msec). (6) All lesions but one were hyperdense on non-contrast-enhanced CT, although only three had unequivocal calcification. The possibility of hyperdensity due to blood or iron deposition is discussed

  19. In vivo characterisation of soft tissue tumours by 1.5-T proton MR spectroscopy

    To determine whether proton magnetic resonance spectroscopy (1H-MRS) can help differentiate between benign and malignant soft tissue lesions, and to assess if there is a correlation between 1H-MRS data and the mitotic index. MR measurements were performed in 43 patients with soft tissue tumours >15 mm in diameter. Six cases were excluded for technical failure. Examinations were performed at 1.5 T using a single-voxel point resolved spectroscopy sequence (PRESS) with TR/TE = 2000/150 ms. The volume of interest was positioned within the lesion avoiding inclusion of necrotic regions. In all patients, a histological diagnosis was obtained and the corresponding mitotic index was also computed. 1H-MRS results and histopathological findings were compared using the chi-squared test and correlation coefficient. Choline was detected in 18/19 patients with malignant tumours and in 3/18 patients with benign lesions. The three benign lesions included one desmoid tumour, one ossificans myositis and one eccrine spiradenoma. Choline was not detected in 15 patients with benign lesions or in one patient with dermatofibrosarcoma protuberans. Resulting 1H-MRS sensitivity and specificity were 95% and 83% respectively. Absence of choline peak is highly predictive of benign tumours suggesting that 1H-MRS can help to differentiate malignant from benign tumours. (orig.)

  20. Conceptual design of the CMS 4 tesla solenoid

    The detection of new physics signals at the highest luminosities available in proton-proton collisions at LHC requires identification and precise measurement of muons, photons and electrons. Toroidal and solenoidal fields were considered at the beginning of the design. For the CMS detector, the choice of a compact design led to the choice of a strong magnetic field. The most practical magnet that can generate a strong magnetic field is a solenoid. A long (about 13 m) superconducting solenoid of large radius generating a magnetic field of 4 T guarantees good momentum resolution. The magnetic flux is returned via a 1.8 m thick iron yoke of a weight of 12,000 tonnes. The magnetic stored energy is 2.52 GJ and the coil total weight is 500 tonnes. The coil main design features are indirect cooling, pure aluminum stabilization and mechanically reinforced conductor. It is a four layer winding, composed of 4 axial sections bolted together

  1. Status of the PuMa-ECR (Pulsed Magnetic field)

    Synchrotrons like the heavy ion synchrotron SIS at GSI need an efficient low duty cycle injector (typical 1 pulse/s and 200 μs pulse length). To improve the peak current, an ECR ion source has been designed using a pulsed magnetic field to force ion extraction. We replaced the hexapole of a 10 GHz MINIMAFIOS ECR ion source by a vacuum chamber containing a watercooled bilayered solenoid coil and a decapole permanent magnetic structure. A pulse line feeds the solenoid with a 250 μs pulse which increases the magnetic field in the minimum B region by 0.3 Tesla. This process opens the magnetic bottle along the beam axis resulting in an extracted ion pulse. First tests of the PuMa-ECR configuration in cw and pulsed operation are presented and analysed. (orig.)

  2. 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.

  3. New diagnostic possibilities for solenoid valves. Neue Diagnosemoeglichkeiten fuer Magnetventile

    Kluever, G. (Herion-Werke KG, Fellbach (Germany))

    1993-05-01

    A diagnostic device, which distinguishes itself by its simple control and operation, has been developed for the early detection of damage in solenoid valves. This device provides all the information which is important for early detection of damage in a VDU representation. Deviations from the specified design power balance of the solenoid valves are detected by comparison of repeat measurements with master diagrams, whilst the calibration curves are superimposed on the monitor. Measurement data input and management are supported by a menu-controlled programme. (orig.)

  4. Operating experience feedback report - Solenoid-operated valve problems

    This report highlights significant operating events involving observed or potential common-mode failures of solenoid-operated valves (SOVs) in US plants. These events resulted in degradation or malfunction of multiple trains of safety systems as well as of multiple safety systems. On the basis of the evaluation of these events, the Office for Analysis and Evaluation of Operational Data (AEOD) of the US Nuclear Regulatory Commission (NRC) concludes that the problems with solenoid-operated valves are an important issue that needs additional NRC and industry attention. This report also provides AEOD's recommendations for actions to reduce the occurrence of SOV common-mode failures. 115 refs., 7 figs., 2 tabs

  5. 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.)

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

    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.)

  7. Imaging appearance of surgical sponges at 1.5 T MRI: An in vitro study

    Ho, Lisa M., E-mail: lisa.ho@duke.edu [Department of Radiology, Box 3808, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710 (United States); Merkle, Elmar M. [Department of Radiology, Box 3808, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710 (United States); Kuo, Paul C. [Department of Surgery, Box 3522, Duke University Medical Center, Durham, NC (United States); Paulson, Erik K. [Department of Radiology, Box 3808, Duke University Medical Center, 2301 Erwin Road, Durham, NC 27710 (United States)

    2011-11-15

    Objective: To predict the MR appearance of retained surgical textiles in the acute setting by using an in vitro phantom and body MR imaging protocols. Methods: Three surgical sponges were embedded in clear gelatin. One of these sponges was soaked in fresh human blood and the other two sponges were embedded dry. The following sequences were acquired at 1.5 T: T1W 3D gradient echo with chemical shift saturation (VIBE, volumetric interpolated breath-hold examination), 3D gradient dual echo T1W (in and opposed phase), 2D T2W single shot fast spin echo (HASTE, half-fourier acquisition single shot turbo spin echo), and 3D T2W fast spin echo (SPACE, sampling perfection with application optimized contrast using different flip angle evolutions). Results: The radiopaque marker within the surgical sponge appears as a linear hypointense structure on T1W and T2W images. Slightly increased conspicuity of the radiopaque marker is seen on the in phase gradient dual echo images compared with the opposed phase gradient dual echo images, likely due to magnetic susceptibility effect. The surgical sponge material is invisible on the T1W images and appears hypointense on the T2W images. Owing to the T1W hyperintensity and T2W hypointensity of blood, the radiopaque marker within the blood soaked gauze is visible on the T1W images but obscured on the T2W images. Conclusions: We describe the in vitro MR appearance of retained surgical sponges in order to simulate their appearance in the acute setting prior to the mass-like foreign body reaction which may occur in the chronic phase.

  8. Aharonov–Bohm effect in resonances for scattering by three solenoids

    Tamura, Hideo

    2015-01-01

    We study how the Aharonov–Bohm effect is reflected in the location of quantum resonances for scattering by three solenoids at large separation. We also discuss what happens in the case of four solenoids.

  9. Energy losses in the D0 β solenoid cryostat caused by current changes

    The proposed D0 β solenoid is a superconducting solenoid mounted inside an aluminum tube which supports the solenoid winding over it's full length. This aluminum support tube, also called bobbin, is therefore very tightly coupled to magnetic flux changes caused by solenoid current variations. These current changes in the solenoid, will cause answer currents to flow in the resistive bobbin wall and therefore cause heat losses. The insertion of an external dump resistor in the solenoid current loop reduces energy dissipation inside the cryostat during a quench and will shorten the discharge time constant. This note presents a simple electrical model for the coupled bobbin and solenoid and makes it easier to understand the circuit behavior and losses. Estimates for the maximum allowable rate of solenoid current changes, based on the maximum permissible rate of losses can be made using this model

  10. Structural analysis of a superconducting central solenoid for the Tokamak Physics Experiment

    The Tokamak Physics Experiment (TPX) concept design uses superconducting coils to accomplish magnetic confinement. The central solenoid (CS) magnet is divided vertically into 8 equal segments which are powered independently. The eddy current heating from the pulsed operation is too high for a case type construction; therefore, a open-quotes no caseclose quotes design has been chosen. This open-quotes no caseclose quotes design uses the conductor conduit as the primary structure and the electrical insulation as a structural adhesive. This electrical insulation is the open-quotes weak linkclose quotes in the coil winding pack structure and needs to be modeled in detail. A global finite element model with smeared winding pack properties was used to study the CS magnet structural behavior. The structural analysis results and peak stresses will be presented

  11. 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.

  12. Design of 9 tesla superconducting solenoid for VECC RIB facility

    An ISOL post-accelerator type of RIB facility is being developed at our centre. The post acceleration scheme of a Radio Frequency Quadrupole (RFQ) followed by five IH LINAC cavities will provide energy of about 1.05 MeV/u. For further accelerating up to 2 MeV/u Superconducting Quarter Wave Resonators (SCQWR) will be used. The radial defocusing of the beam bunch during the acceleration using SCQWRs will be taken care of by a Superconducting Solenoid (SCS) within the same cryostat. In this report the electromagnetic design of an SCS will be discussed. A 9 T SCS having effective length of 340 mm has been designed with the special requirement that the fringing field should fall sharply to a value less than 100 mT at the surfaces of the adjacent superconducting cavities. The designed solenoid comprise of two co-axial split solenoid conductors surrounded by iron shields and a pair of bucking coils. Optimizations have been carried out for the total current sharing of the main coils and the bucking coils as well as for the relative orientation and dimension of each component of the solenoid. (author)

  13. Completion of the ITER central solenoid model coils installation

    The short article details how dozens of problems, regarding the central solenoid model coils installation, were faced and successfully overcome one by one at JAERI-Naga. A black and white photograph shows K. Kwano, a staff member of the JAERI superconducting magnet laboratory, to be still inside the vacuum tank while the lid is already being brought down..

  14. Matching by solenoids in space charge dominated LEBTs

    LI Jin-Hai; TANG Jing-Yu; OUYANG Hua-Fu

    2009-01-01

    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.

  15. Construction and test of the 'Cello' thin-wall solenoid

    A large 'thin wall' superconducting solenoid has been constructed at Saclay and then mounted on a large detector 'Cello', which is one of the experiments installed on the e+e- colliding beam facility 'Petra' at Desy (Hamburg). The complete magnet system, in addition to this main solenoid, includes two compensating solenoids symmetrically located on each side of the main one, a thick 1000-tonne iron shielding intended as a hadron filter and a 300 Watt helium refrigerator feeding the three magnets in closed cycle. The two superconducting compensating coils have been designed and constructed at the ITP of Karlsruhe and are described in papers IC-12 and IC-13 of the present conference. The major requirement for the main solenoid was very light weight or 'transparency' to radiations. The amount of material allowed for the radial thickness of the complete magnet (including thermal shields and vacuum walls) had not to exceed half a radiation length, which is equivalent to 45 mm of aluminium

  16. Structure design of the central solenoid in JT-60SA

    The upgrade of JT-60U magnet system to superconducting coils (JT-60SA: JT-60 Super Advanced) has been decided by parties of Japanese government (JA) and European commission (EU) in the framework of the Broader Approach (BA) agreement. The magnet system for JT-60SA consists of a central solenoid (CS), equilibrium field(EF) coils, toroidal field(TF) coils. The central solenoid consists the four winding pack modules. In order to counteract the thermal contraction as well as the electric magnetic repulsion and attraction together with other forces generated in each module, it is necessary to apply pre-loading to the support structure of the solenoid and to pursue a structure which is capable of sustaining such loading. In the present report, the structural design of the supporting structure of the solenoid and the jackets of the modules is verified analytically, and the results indicate that the structural design satisfies the 'Codes for Fusion Facilities - Rules on Superconducting Magnet Structure -'. (author)

  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. The large superconducting solenoids for the g-2 muon storage ring

    The g-2 muon storage ring at Brookhaven National Laboratory consists of four large superconducting solenoids. The two outer solenoids, which are 15.1 meters in diameter, share a common cryostat. The two inner solenoids, which are 13.4 meters in diameter, are in separate cryostats. The two 24 turn inner solenoids are operated at an opposite polarity from the two 24 turn outer solenoids. This generates a dipole field between the inner and outer solenoids. The flux between the solenoids is returned through a C shaped iron return yoke that also shapes the dipole field. The integrated field around the 14 meter diameter storage ring must be good to about 1 part in one million over the 90 mm dia. circular cross section where the muons are stored, averaged over the azimuth. When the four solenoids carry their 5300 A design current, the field in the 18 centimeter gap between the poles is 1.45 T. When the solenoid operates at its design current 5.5 MJ is stored between the poles. The solenoids were wound on site at Brookhaven National Laboratory. The cryostats were built around the solenoid windings which are indirectly cooled using two-phase helium

  19. Laser ion source with long pulse width for RHIC-EBIS

    The Electron Beam Ion Source (EBIS) at Brookhaven National Laboratory is a new heavy ion-projector for RHIC and NASA Space Radiation Laboratory. Laser Ion Source (LIS) with solenoid can supply many kinds of ion from solid targets and is suitable for long pulse length with low current as ion provider for RHIC-EBIS. In order to understand a plasma behavior for fringe field of solenoid, we measure current, pulse width and total ion charges by a new ion probe. The experimental result indicates that the solenoid confines the laser ablation plasma transversely. Laser ion source needs long pulse length with limited current as primary ion provider for RHIC-EBIS. New ion probe can measure current distribution for the radial positions along z axis. The beam pulse length is not effected by magnetic field strength. However, the currents and charges decay with the distance from the end of solenoid. These results indicate that solenoid field has important role for plasma confinement not longitudinally but transversely and solenoid is able to have long pulse length with sufficient total ion charges. Moreover, the results are useful for a design of the extraction system for RHIC-EBIS.

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

    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.

  1. 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.

  2. Design report for an indirectly cooled 3-m diameter superconducting solenoid for the Fermilab Collider Detector Facility

    The Fermilab Collider Detector Facility (CDF) is a large detector system designed to study anti pp collisions at very high center of mass energies. The central detector for the CDF shown employs a large axial magnetic field volume instrumented with a central tracking chamber composed of multiple layers of cylindrical drift chambers and a pair of intermediate tracking chambers. The purpose of this system is to determine the trajectories, sign of electric charge, and momenta of charged particles produced with polar angles between 10 and 170 degrees. The magnetic field volume required for tracking is approximately 3.5 m long an 3 m in diameter. To provide the desired δp/sub T/p/sub T/ less than or equal to 1.5% at 50 GeV/c using drift chambers with approx. 200μ resolution the field inside this volume should be 1.5 T. The field should be as uniform as is practical to simplify both track finding and the reconstruction of particle trajectories with the drift chambers. Such a field can be produced by a cylindrical current sheet solenoid with a uniform current density of 1.2 x 106 A/m (1200 A/mm) surrounded by an iron return yoke. For practical coils and return yokes, both central electromagnetic and central hadronic calorimetry must be located outside the coil of the magnet. This geometry requires that the coil and the cryostat be thin both in physical thickness and in radiation and absorption lengths. This dual requirement of high linear current density and minimal coil thickness can only be satisfied using superconducting technology. In this report we describe the design for an indirectly cooled superconducting solenoid to meet the requirements of the Fermilab CDF. The components of the magnet system are discussed in the following chapters, with a summary of parameters listed in Appendix A

  3. 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.

  4. The Design and Construction of the MICE Spectrometer Solenoids

    Wang, Bert; Wahrer, Bob; Taylor, Clyde; Xu, L.; Chen, J. Y.; Wang, M.; Juang, Tiki; Zisman, Michael S.; Virostek, Steve P.; Green, Michael A.

    2008-08-02

    The purpose of the MICE spectrometer solenoid is to provide a uniform field for a scintillating fiber tracker. The uniform field is produced by a long center coil and two short end coils. Together, they produce 4T field with a uniformity of better than 1% over a detector region of 1000 mm long and 300 mm in diameter. Throughout most of the detector region, the field uniformity is better than 0.3%. In addition to the uniform field coils, we have two match coils. These two coils can be independently adjusted to match uniform field region to the focusing coil field. The coil package length is 2544 mm. We present the spectrometer solenoid cold mass design, the powering and quench protection circuits, and the cryogenic cooling system based on using three cryocoolers with re-condensers.

  5. 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.

  6. 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.

  7. Preliminary Test Results for the MICE Spectrometer Superconducting Solenoids

    Virostek, Steve P.; Green, Michael A; Li, Derun; Zisman, Michael S.; Wang, S.T.; Wahrer, R.; Taylor, Clyde; Lu, X.; Chen, J. Y.; Wang, Mimi; Juang, Tiki

    2008-08-02

    This report describes the MICE spectrometer solenoids as built. Each magnet consists of five superconducting coils. Two coils are used to tune the beam going from or to the MICE spectrometer from the rest of the MICE cooling channel. Three spectrometer coils (two end coils and a long center coil) are used to create a uniform 4 T field (to {+-}0.3 percent) over a length of 1.0 m within a diameter of 0.3 m. The three-coil spectrometer set is connected in series. The two end coils use small power supplies to tune the uniform field region where the scintillating fiber tracker is located. This paper will present the results of the preliminary testing of the first spectrometer solenoid.

  8. Preliminary Test Results for the MICE Spectrometer Superconducting Solenoids

    This report describes the MICE spectrometer solenoids as built. Each magnet consists of five superconducting coils. Two coils are used to tune the beam going from or to the MICE spectrometer from the rest of the MICE cooling channel. Three spectrometer coils (two end coils and a long center coil) are used to create a uniform 4 T field (to ±0.3 percent) over a length of 1.0 m within a diameter of 0.3 m. The three-coil spectrometer set is connected in series. The two end coils use small power supplies to tune the uniform field region where the scintillating fiber tracker is located. This paper will present the results of the preliminary testing of the first spectrometer solenoid

  9. Transverse emittance measurement at REGAE via a solenoid scan

    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.

  10. Refrigerator and Solenoid Run Summary August/September 1999

    The helium refrigerator was cooled down and operated for the third time since its installation. D-Zero's 2 Tesla superconducting solenoid was cooled down and operated for its second time since its installation into the D-Zero detector. This engineering note summarizes the cryogenic aspects of the test run and performance measurements made. The main purpose of this run was to do field mapping of the solenoid with different combinations of field polarity on the Solenoid and CF iron magnets. This was accomplished. A second purpose was to test the lower field joint repair that was done in January 1999. This field joint had a measurable voltage drop across the soldered bus splice. The repair was an undoing of the joint, extensive cleaning of the bus, and then welding the splice. The repair was successful, no voltage drop was measured and the magnet behaved nicely. A parasitic purpose was to get some operating time on the refrigerator, measure the refrigeration performance, and measure the heat leak in the VLPC lines mounted on the detector platform. Refrigerator performance was spot checked, and was found to be 60 watts (10%) less than generic operating curves. At this level of performance, the operating margin for the full solenoid and VLPC system will be 75 watts (15%) which is somewhat uncomfortable from an operational stand point. The VLPC lines were operated and heat leak numbers of around 40 watts was measured for each pipe section including the supply u-tubes to the detector, the bayonet can, valve box on the platform and the piping back to the refrigerator valve box. Another purpose of the test run was to test the compatibility of other detector components with the new central magnetic field environment. I do not know the results of these tests.

  11. Worcester 1 Inch Solenoid Actuated Gas Operated SCHe System Valves

    MISKA, C.R.

    2000-11-13

    1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated.

  12. Electron Beam Size Measurements in a Cooling Solenoid

    Kroc, Thomas K; Burov, Alexey; Seletsky, Sergey; Shemyakin, Alexander V

    2005-01-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide effective cooling of the antiprotons in the Recycler. A measurement system was developed using movable appertures and steering bumps to measure the beam size in a 20 m long, nearly continuous, solenoid. This paper discusses the required beam parameters, the implimentation of the measurement system and results for our application.

  13. 1.5T MRI-guided trans-perineal laser ablation of locally recurrent prostate adenocarcinoma

    McPhail, E. Frederick; Mynderse, Lance A.; Callstrom, Matthew R.; Gorny, Krzysztof R.; McNichols, Roger J.; Atwell, Thomas D.; Gettman, Matthew T.; Amrami, Kimberly K.; Kawashima, Akira; Woodrum, David A.

    2010-02-01

    Introduction: Biochemical recurrence of prostate cancer after definitive therapy with radical prostatectomy (RP) is known to occur between 25-30%. We present the first known case of 1.5T MRI guided ablation using laser interstitial thermal therapy (LITT) for locally recurrent prostate cancer following RP. Methods: The patient elected to undergo MRI-guided LITT of the biopsy proven cancer recurrence using an FDAapproved MRI compatible, 980nm, 15-watt laser system with MR thermometry. Under T2-weighted MR(1.5T Siemens) imaging, guidance and targeting of the lesions with trans-perineal placement of laser applicators. Multiple cycles of laser energy were used to ablate the tumor. A MRI-compatible urethral cooling catheter was placed to prevent urethral thermal damage. Results: Intra-procedural temperature mapping allowed continuous monitoring of the ablation zone and permitted ablation control until tumor coverage was achieved. Additionally, the protective cooling effects of the urethral cooling catheter could also be seen with the temperature mapping. Post-ablation gadolinium and T2 weighted MR imaging demonstrated an ablation defect encompassing the recurrent tumor with no residual hyper-enhancing nodules. Three month follow-up shows no residual or recurrent tumor seen on MR imaging. Conclusion: This represents the first known, successful, MRI-guided, LITT procedures at 1.5T for locally recurrent prostate adenocarcinoma following RP.

  14. Preliminary study of 1.5 T MR guided radio-frequency ablation for hepatic malignant tumors

    Objective: To explore the technique and feasibility of using 1.5 T MR guided radio- frequency ablation (RFA) of hepatic malignant tumor. Methods: Twenty three patients with 44 malignant lesions in liver confirmed by pathology were treated with 1.5 T MR guided RFA using MR compatible multipolar RF electrode. Only patients refusing open surgery or suffering from unresectable lesions were included. Of these, 11 patients had primary hepatic carcinoma and 12 patients had hepatic metastases. The mean maximal diameter of lesions was (3.3±1.8) cm. Postoperative MR was performed; the ablation zone covered and exceeded 0.5 to 1.0 cm to the margin of initial tumor was considered successful. Results: All ablations were successful and lesions created by radio frequency were large enough to cover the initial tumor volume in all cases. No severe complications such as biliary fistula, perforation of diaphragmatic muscle, postoperative jaundice and pneumothorax were encountered. The mean operative time was (93±33) min. The RF electrodes appeared in MRI as low signal structure. The ablation lesions were well-defined hyper- intensity in T1WI and hypo-intensity with a thin rim of high signal intensity on T2WI and DWI. Conclusion: 1.5 T MR guided RFA of hepatic malignant tumor is an effective and safe technique. (authors)

  15. Thermal design of the Mu2e detector solenoid

    The reference design for a superconducting detector solenoid (DS) for the Mu2e experiment has been completed. In this study, the main functions of the DS are to provide a graded field in the region of the stopping target, which ranges from 2 to 1 T and a uniform precision magnetic field of 1 T in a volume large enough to house a tracker downstream of the stopping target. The inner diameter of the magnet cryostat is 1.9 m and the length is 10.9 m. The gradient section of the magnet is about 4 m long and the spectrometer section with a uniform magnetic field is about 6 m long. The inner cryostat wall supports the stopping target, tracker, calorimeter and other equipment installed in the DS. This warm bore volume is under vacuum during operation. It is sealed on one end by the muon beam stop, while it is open on the other end where it interfaces with the Transport Solenoid. The operating temperature of the magnetic coil is 4.7 K and is indirectly cooled with helium flowing in a thermosiphon cooling scheme. This paper describes the thermal design of the solenoid, including the design aspects of the thermosiphon for the coil cooling, forced flow cooling of the thermal shields with 2 phase LN2 (Liquid Nitrogen) and the transient studies of the cool down of the cold mass as well

  16. Field measurements in the Fermilab electron cooling solenoid prototype

    Crawford, A C

    2003-01-01

    To increase the Tevatron luminosity, Fermilab is developing a high-energy electron cooling system [1] to cool 8.9-GeV/c antiprotons in the Recycler ring. The schematic layout of the Recycler Electron Cooling (REC) system is shown in Figure 1. Cooling of antiprotons requires a round electron beam with a small angular spread propagating through a cooling section with a kinetic energy of 4.3 MeV. To confine the electron beam tightly and to keep its transverse angles below 10 sup - sup 4 rad, the cooling section will be immersed into a solenoidal field of 50-150G. As part of the R and D effort, a cooling section prototype consisting of 9 modules (90% of the total length of a future section) was assembled and measured. This paper describes the technique of measuring and adjusting the magnetic field quality in the cooling section and presents preliminary results of solenoid prototype field measurements. The design of the cooling section solenoid is discussed in Chapter 2. Chapter 3 describes details of a dedicated ...

  17. 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.

  18. 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.

  19. 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.)

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

    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.)

  1. Optimum b value for resolving crossing fibers: a study with standard clinical b value using 1.5-T MR

    Akazawa, Kentaro; Yamada, Kei; Matsushima, Shigenori; Goto, Mariko; Yuen, Sachiko; Nishimura, Tsunehiko

    2010-01-01

    Introduction We sought to investigate the optimum b value for resolving crossing fiber using high-angular resolution diffusion imaging (HARDI)-based multi-tensor tractography. The study tested the standard b values that are commonly used in the routine clinical setting. Methods Ten normal volunteers (five men and five women) with a mean age of 26.3 years (range, 22–32 years) were scanned using a 1.5-T clinical magnetic resonance unit. Single-shot echo-planar imaging was used for diffusion-wei...

  2. Detection circuit of solenoid valve operation and control rod drive mechanism utilizing the circuit

    Object: To detect the operation of a plunger and detect opening and closing operations of a solenoid valve driving device due to change in impedance of a coil for driving the solenoid valve to judge normality and abnormality of the solenoid valve, thereby increasing reliance and safety of drive and control apparatus of control rods. Structure: An arrangement comprises a drive and operation detector section wherein the operation of a solenoid driving device for controlling power supply to a coil for driving the solenoid valve to control opening and closing of the solenoid valve, and a plunger operation detector section for detecting change in impedance of the drive coil to detect that the plunger of the solenoid valve is either in the opening direction or closing direction, whereby a predetermined low voltage such as not to activate the solenoid valve even when the solenoid valve is open or closed is applied to detect a current flowing into the coil at that time, thus detecting an operating state of the plunger. (Yoshino, Y.)

  3. Analysis of electromagnetic field of direct action solenoid valve with current changing

    Control rod hydraulic drive mechanism(CRHDM) is a newly invented patent of Institute of Nuclear and New Energy Technology of Tsinghua University. The direct action solenoid valve is the key part of this technology, so the performance of the solenoid valve directly affects the function of the CRHDM. With the current and the air gap changing,the electromagnetic field of the direct action solenoid valve was analyzed using the ANSYS software,which was validated by the experiment. The result shows that the electromagnetic force of the solenoid valve increases with the current increasing or the gap between the two armatures decreasing. Further more, the working current was confirmed. (authors)

  4. 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.

  5. Magnetoelectric excitations in hexaferrites utilizing solenoid coil for sensing applications

    Zare, Saba; Izadkhah, Hessam; Somu, Sivasubramanian; Vittoria, Carmine, E-mail: c.vittoria@neu.edu

    2015-11-01

    We have developed techniques for H- and E-field sensors utilizing single phase magnetoelectric hexaferrite materials in the frequency range of 100 Hz to 10 MHz. Novel excitation method incorporating solenoid coils and single and multi-capacitor banks were developed and tested for sensor detections. For H-field sensing we obtained sensitivity of about 3000 V/mG and for E-field sensing the sensitivity was 10{sup −4} G/Vm{sup −1}. Tunability of about 0.1% was achieved for tunable inductor applications. However, the proposed designs lend themselves to significant (~10{sup 6}) improvements in sensitivity and tunability.

  6. Charged particle scattering on two infinite cylindrical solenoids

    Charged particle scattering on two infinitely parallel cylindrical solenoids with similar by value and inverse by the sign magnetic fields is considered. Scattering amplitude is calculated in the 1st Born and high energy approximations. In both cases the differential cross section is nonsingular and the integral one - finite. Specific examples demonstrating that in one and the same multi-connection space under nontrivial vector-potentials and unambigous wave functions Aharonov-Bohm (AB) effect can exist but it can be absent as well. It is shown that an alternative AB effect interpretation as scattering in magnetic field leakages meets sufficient difficulties

  7. Magnetoelectric excitations in hexaferrites utilizing solenoid coil for sensing applications

    We have developed techniques for H- and E-field sensors utilizing single phase magnetoelectric hexaferrite materials in the frequency range of 100 Hz to 10 MHz. Novel excitation method incorporating solenoid coils and single and multi-capacitor banks were developed and tested for sensor detections. For H-field sensing we obtained sensitivity of about 3000 V/mG and for E-field sensing the sensitivity was 10−4 G/Vm−1. Tunability of about 0.1% was achieved for tunable inductor applications. However, the proposed designs lend themselves to significant (~106) improvements in sensitivity and tunability

  8. Applications of a 6.5T Superconducting Solenoidal Separator

    Williams E.

    2012-10-01

    Full Text Available A 6.5 Tesla superconducting gas-filled solenoid (SOLITAIRE has been developed at the Heavy Ion Accelerator Facility at the ANU as a reaction product separator. Key features of the device allowing its application for precise measurement of heavy ion fusion cross sections are described. The physical separation of beam particles and the high efficiency (~80% transport of heavy ion fusion products open up applications in nuclear structure physics, and in materials science. Finally, the developments to allow its application to providing beams of light radioactive isotopes (SOLEROO are described.

  9. Gadoxate-enhanced T1-weighted MR cholangiography: comparison of 1.5 T and 3.0 T

    Purpose: to qualitatively and quantitatively compare gadoxate-enhanced T1-weighted MR cholangiography at magnetic field strengths of 1.5 T and 3.0 T. Materials and methods: a total of 40 patients with a non-dilated biliary system were retrospectively included in the study. T1-weighted MR cholangiography 20 min after IV administration of 0.025 mmol/kg gadoxate (Primovist trademark) was performed in 20 patients at 1.5 T and in another 20 patients at 3.0 T. Contrast-to-noise ratios (CNR) of the biliary system (common bile duct - CBD, right hepatic duct - RHD, left hepatic duct - LHD) compared to the periductal tissue were measured. Two radiologists also qualitatively assessed the visibility of the intrahepatic and extrahepatic biliary system using a six-point rating scale. The Mann-Whitney U-test and Pearson's correlation coefficient were used for statistical analysis. Results: the CNRs of the intrahepatic and extrahepatic hepatic bile ducts were significantly higher at 3.0 T. Qualitative analysis showed a significant superiority for 3.0 T in the delineation of the intrahepatic biliary system (RHD, LHD, segmental ducts). (orig.)

  10. Gadoxate-enhanced T1-weighted MR cholangiography: comparison of 1.5 T and 3.0 T

    Koelblinger, C.; Schima, W.; Weber, M.; Mang, T.; Nemec, S.; Kulinna-Cosentini, C.; Bastati, N.; Ba-Ssalamah, A. [Universitaetsklinik fuer Radiodiagnostik, Medizinische Univ. Wien (Austria)

    2009-06-15

    Purpose: to qualitatively and quantitatively compare gadoxate-enhanced T1-weighted MR cholangiography at magnetic field strengths of 1.5 T and 3.0 T. Materials and methods: a total of 40 patients with a non-dilated biliary system were retrospectively included in the study. T1-weighted MR cholangiography 20 min after IV administration of 0.025 mmol/kg gadoxate (Primovist trademark) was performed in 20 patients at 1.5 T and in another 20 patients at 3.0 T. Contrast-to-noise ratios (CNR) of the biliary system (common bile duct - CBD, right hepatic duct - RHD, left hepatic duct - LHD) compared to the periductal tissue were measured. Two radiologists also qualitatively assessed the visibility of the intrahepatic and extrahepatic biliary system using a six-point rating scale. The Mann-Whitney U-test and Pearson's correlation coefficient were used for statistical analysis. Results: the CNRs of the intrahepatic and extrahepatic hepatic bile ducts were significantly higher at 3.0 T. Qualitative analysis showed a significant superiority for 3.0 T in the delineation of the intrahepatic biliary system (RHD, LHD, segmental ducts). (orig.)

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

    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 V95% and V107% and bowel area V5Gy, V10Gy, V15Gy, V20Gy, and V25Gy 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 V95% and V107% 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 V95% 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 cm3. V95% differences between 0 and 1.5 T were all within 2%. The V107% was below 1% in 46 out of 50 fractions, and increased to 3% in the remaining fractions due to appearing air of around 120 cm3. For comparison, V107% was <1% at 0 T for all fractions. In the bowel area, the V15Gy varied strongest from fraction to fraction, but differences between 1.5 and 0 T were minimal with an average difference of 2.3 cm3 (SD = 18.7 cm3, 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

  12. 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.

  13. Integration of RFQ beam coolers and solenoidal magnetic fields

    Cavenago, M., E-mail: cavenago@lnl.infn.it; Maggiore, M.; Porcellato, A. M.; Chiurlotto, F.; Comunian, M.; Galatà, A. [INFN-LNL, viale dell’Universitá n.2, 35020 Legnaro (PD) (Italy); Romé, M.; Maero, G.; Cavaliere, F. [INFN-Sezione di Milano and Physics Department, University of Milano, Milano (Italy)

    2016-02-15

    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 B{sub z} up to 0.2 T, where z is the solenoid axis. Confinement in the transverse plane is provided both by B{sub z} and the rf voltage V{sub rf} (up to 1 kV at few MHz). Transport is provided by a static electric field E{sub z} (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 V{sub rf}. The beamline design and the major parameters V{sub rf}, B{sub z} (which affect the beam transmission optimization) are here reported, with a brief description of the experimental setup.

  14. Assessment of diagnostic methods for solenoid-operated valves

    Solenoid-operated valves (SOVs) were studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary objective of the study was to identify, evaluate, and recommend methods for inspection, surveillance, monitoring, and maintenance of SOVs that can help ensure their operational readiness -- that is, their ability to perform required safety functions under all anticipated operating conditions, since failure of one of these small and relatively inexpensive devices could have serious consequences under certain circumstances. Intrusive techniques requiring the addition of magnetic or acoustic sensors or the application of special test signals were investigated briefly, but major emphasis was placed on the examination of condition-indicating techniques that can be applied with minimal cost and impact on plant operation. These include monitoring coil mean temperature remotely by means of coil dc resistance or ac impedance, determining valve plunger position by means of coil ac impedance, verifying unrestricted SOV plunger movement by measuring current and voltage at their critical bistable (pull-in and drop-out) values, and detecting the presence of shorted turns or insulation breakdown within the solenoid coil using interrupted-current test methods. Experimental results are presented that demonstrate the technical feasibility and praticality of the monitoring techniques assessed in the study, and recommendations for further work are provided

  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. 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.

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

    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 cm3 cubic material was positioned at the center of a 2744 cm3 cubic soft tissue material phantom. The following tissue materials and their densities were used in this study: lung (0.296 g/cm3), 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.

  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. Plasma heating in a long solenoid by a laser or a relativistic electron beam

    Advances in the technology of a large energy laser and/or relativistic electron beam (REB) generator have made it possible to seriously consider a long solenoid reactor concept. This concept has been reviewed. The physical problems in the plasma heating of the long solenoid by a laser or a REB are studied

  20. How MRI Compatible is “MRI Compatible”? A Systematic Comparison of Artifacts Caused by Biopsy Needles at 3.0 and 1.5 T

    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 B0. 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°, B-SSFP, 3.0 T, inner) to 71.4 mm (nitinol, 90°, 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

  1. 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).

  2. Design and Construction of Solenoid Magnetic Lens for Focusing Electron Beam from Thermionic Electron Gun

    Electron gun is an important part of an electron accelerator for producing electron beam to be irradiated on material. The electron gun of electron accelerator constructed at P3TM BATAN, is a thermionic electron gun, A solenoid magnetic lens had been designed and constructed for focusing electron beam extracted from the electron gun in such away that all of the electron beam enter the accelerating tube. Technical specification of the solenoid magnetic lens is given in this paper. Measurement of magnetic field generated by solenoid coil shows that the largest magnetic field is in the middle of the solenoid coil. The test using the thermionic electron gun shows the focusing effect on electron beam by the solenoid magnetic lens. The focus strength is maximum after the coil current reaches 9 A. (author)

  3. 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* analysis. Native myocardial T1 and T2 times at 3 T correlate closely with T2* times at 1.5 T and may be useful for myocardial iron overload quantification. PMID:26872908

  4. Spin-echo and STIR MR imaging of sports-related muscle injuries at 1.5 T

    This paper assesses the value of T2-weighted and short T1 inversion recovery (Stir 1,800,170,27) sequences in the MR diagnosis and follow-up of muscle strain injuries. Fifty-six athletes with clinically diagnosed traumatic muscular damage were studied at 1.5 T with SE T1-weighted, double T2-weighted, and STIR techniques. Images were evaluated in order to detect the presence of muscle tear with associated edema, muscle hemorrhage (focal or diffuse), and perimuscular hemorrhage. The relative conspicuity of muscle injuries on T2-weighted and STIR images was assessed. All acute and subacute muscle injuries were detected on both SE T2-weighted and STIR images, muscle edema and subacute hemorrhage appearing hyperintense to normal muscle. Acute hemorrhage could appear hypointense on T2-weighted images but was always hyperintense on STIR images

  5. In vivo P31-spectroscopy in humans with a 1.5-T whole body scanner: Therapy response of tumors

    The response of tumors to chemotherapy, radiation therapy and hyperthermia was monitored by P-31 spectroscopy. Twenty-five patients underwent 45 examinations performed using a 1.5-T whole-body MR imaging unit. Only superficial tumors of the neck, proximal thigh, and pelvis were included in the study. Spectra were measured by surface coils that matched the size of the tumor. Tumor spectra were characterized by increased PME and PDE levels and by variation in the phosphocreatinine-inorganic phosphate (PCr/Pi) ratio. Five tumors monitored during therapy showed partial changes in the PCr/Pi ratio and in the pH. Early therapeutic control of tumors by means of P-31 spectroscopy is feasible and may be of clinical relevance

  6. Assembly And Test Of A 120 MM Bore 15 T Nb3Sn Quadrupole For The LHC Upgrade

    In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb3Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is to provide appropriate mechanical support to the coils. Compared to the previous LARP Technology Quadrupole and Long Quadrupole magnets, the purpose of HQ is also to demonstrate accelerator quality features such as alignment and cooling. So far, 8 HQ coils have been fabricated and 4 of them have been assembled and tested in HQ01a. This paper presents the mechanical assembly and test results of HQ01a.

  7. 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.

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

    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

  9. Functional MRI of the cervical spinal cord on 1.5 T with fingertapping: to what extent is it feasible?

    Until recently, functional magnetic resonance imaging (fMRI) with blood oxygen level-dependent (BOLD) contrast, was mainly used to study brain physiology. The activation signal measured with fMRI is based upon the changes in the concentration of deoxyhaemoglobin that arise from an increase in blood flow in the vicinity of neuronal firing. Technical limitations have impeded such research in the human cervical spinal cord. The purpose of this investigation was to determine whether a reliable fMRI signal can be elicited from the cervical spinal cord during fingertapping, a complex motor activity. Furthermore, we wanted to determine whether the fMRI signal could be spatially localized to the particular neuroanatomical location specific for this task. A group of 12 right-handed healthy volunteers performed the complex motor task of fingertapping with their right hand. T2*-weighted gradient-echo echo-planar imaging on a 1.5-T clinical unit was used to image the cervical spinal cord. Motion correction was applied. Cord activation was measured in the transverse imaging plane, between the spinal cord levels C5 and T1. In all subjects spinal cord responses were found, and in most of them on the left and the right side. The distribution of the activation response showed important variations between the subjects. While regions of activation were distributed throughout the spinal cord, concentrated activity was found at the anatomical location of expected motor innervation, namely nerve root C8, in 6 of the 12 subjects. fMRI of the human cervical spinal cord on an 1.5-T unit detects neuronal activity related to a complex motor task. The location of the neuronal activation (spinal cord segment C5 through T1 with a peak on C8) corresponds to the craniocaudal anatomical location of the neurons that activate the muscles in use. (orig.)

  10. Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

    Yikilmaz, Ali; Koc, Ali; Coskun, Abdulhakim (Dept. of Radiology, Erciyes Medical School, Kayseri (Turkey)); Ozturk, Mustafa K (Dept. of Pediatric Infectious Diseases, Erciyes Medical School, Kayseri (Turkey)); Mulkern, Robert V; Lee, Edward Y (Dept. of Radiology and Dept. of Medicine, Pulmonary Div., Children' s Hospital Boston and Harvard Medical School, Boston (United States)), email: Edward.lee@childrens.harvard.edu

    2011-10-15

    Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years +- 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weighted B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children

  11. Evaluation of pneumonia in children: comparison of MRI with fast imaging sequences at 1.5T with chest radiographs

    Background Although there has been a study aimed at magnetic resonance imaging (MRI) evaluation of pneumonia in children at a low magnetic field (0.2T), there is no study which assessed the efficacy of MRI, particularly with fast imaging sequences at 1.5T, for evaluating pneumonia in children. Purpose To investigate the efficacy of chest MRI with fast imaging sequences at 1.5T for evaluating pneumonia in children by comparing MRI findings with those of chest radiographs. Material and Methods This was an Institutional Review Board-approved, HIPPA-compliant prospective study of 40 consecutive pediatric patients (24 boys, 16 girls; mean age 7.3 years ± 6.6 years) with pneumonia, who underwent PA and lateral chest radiographs followed by MRI within 24 h. All MRI studies were obtained in axial and coronal planes with two different fast imaging sequences: T1-weighted FFE (Fast Field Echo) (TR/TE: 83/4.6) and T2-weighted B-FFE M2D (Balanced Fast Field Echo Multiple 2D Dimensional) (TR/TE: 3.2/1.6). Two experienced pediatric radiologists reviewed each chest radiograph and MRI for the presence of consolidation, necrosis/abscess, bronchiectasis, and pleural effusion. Chest radiograph and MRI findings were compared with Kappa statistics. Results All consolidation, lung necrosis/abscess, bronchiectasis, and pleural effusion detected with chest radiographs were also detected with MRI. There was statistically substantial agreement between chest radiographs and MRI in detecting consolidation (k = 0.78) and bronchiectasis (k = 0.72) in children with pneumonia. The agreement between chest radiographs and MRI was moderate for detecting necrosis/abscess (k = 0.49) and fair for detecting pleural effusion (k = 0.30). Conclusion MRI with fast imaging sequences is comparable to chest radiographs for evaluating underlying pulmonary consolidation, bronchiectasis, necrosis/abscess, and pleural effusion often associated with pneumonia in children

  12. Specificity of choline metabolites for in vivo diagnosis of breast cancer using 1H MRS at 1.5 T

    The purpose was to determine if in vivo proton magnetic resonance spectroscopy (1H MRS) at 1.5 T can accurately provide the correct pathology of breast disease. Forty-three asymptomatic volunteers including three lactating mothers were examined and compared with 21 breast cancer patients. Examinations were undertaken at 1.5 T using a purpose-built transmit-receive single breast coil. Single voxel spectroscopy was undertaken using echo times of 135 and 350 ms. The broad composite resonance at 3.2 ppm, which includes contributions from choline, phosphocholine (PC), glycerophosphocholine (GPC), myo-inositol and taurine, was found not to be a unique marker for malignancy providing a diagnostic sensitivity and specificity of 80.0 and 86.0%, respectively. This was due to three of the asymptomatic volunteers and all of the lactating mothers also generating the broad composite resonance at 3.2 ppm. Optimised post-acquisitional processing of the spectra resolved a resonance at 3.22 ppm, consistent with PC, in patients with cancer. In contrast the spectra recorded for three false-positive volunteers, and the three lactating mothers had a resonance centred at 3.28 ppm (possibly taurine, myo-inositol or GPC). This improved the specificity of the test to 100%. Careful referencing of the spectra and post-acquisitional processing intended to optimise spectral resolution of in vivo MR proton spectra from human breast tissue resolves the composite choline resonance. This allows the distinction of patients with malignant disease from volunteers with a sensitivity of 80% and specificity of 100%. Therefore, resolution of the composite choline resonance into its constituent components improves the specificity of the in vivo 1H MRS method, but does not overcome the problem of 20% false-negatives. (orig.)

  13. Effect of subcutaneous butylscopolamine administration in the reduction of peristaltic artifacts in 1.5-T MR fast abdominal examinations

    In abdominal MR imaging, ghost artifacts from noncyclic bowel movements can reduce the quality of the images. Although pharmacologic suppression of motion is effective, no study has being conducted to analyze the influence of drug motion suppression on fast breath-hold 1.5-T examinations of the upper abdomen. A prospective, randomized, double-blind trial was conducted in 50 patients. Patients were randomly distributed into two groups: The control group received only an oral solution, whereas the other group received the oral solution plus a subcutaneous injection of 20 mg of butylscopolamine 10 min before the MR examination. Breath-hold T1-weighted gradient-recalled-echo (GRE) MR images were obtained in a 1.5-T superconductive unit. Quantitative image analysis was performed with region-of-interest (ROI) measurements of the signal intensity of the liver and in background air anterior and lateral to the patient. A qualitative analysis of the subjective quality of the T1-weighted images was also done, and the adverse reactions were registered. The groups were homogeneous regarding age, gender, and weight distribution. No significant differences in the signal intensity of the liver and in the incoherent noise measurements were found between the two groups. Gastrointestinal noise showed significant differences between groups, with lower values for the butylscopolamine group compared with the control group. There was also a statistically significant difference in the image quality between groups, and optimal studies were only found in the butylscopolamine group, where most patients had a good-quality evaluation. Regarding adverse events, there were non-significant differences between groups. In conclusion, administration of an antiperistaltic agent to reduce the movements of the gastrointestinal tract diminishes the motion artifacts generated on MR imaging of the abdomen, even at high field strength and with fast imaging sequences. Images of the upper abdomen obtained after pharmacologic suppression of the gastrointestinal movement are of significantly superior quality. (orig.)

  14. Effect of subcutaneous butylscopolamine administration in the reduction of peristaltic artifacts in 1.5-T MR fast abdominal examinations

    Dosda, Rosa; Marti-Bonmati, Luis; Molla, Enrique; Arana, Estanislao [Department of Radiology, Clinica Quiron, Avda. Blasco Ibanez, 14, 46017 Valencia (Spain); Ronchera-Oms, Crisanto L. [Pharmacy University College, Fundacion Universitaria San Pablo CEU, Moncada, 46017 Valencia (Spain)

    2003-02-01

    In abdominal MR imaging, ghost artifacts from noncyclic bowel movements can reduce the quality of the images. Although pharmacologic suppression of motion is effective, no study has being conducted to analyze the influence of drug motion suppression on fast breath-hold 1.5-T examinations of the upper abdomen. A prospective, randomized, double-blind trial was conducted in 50 patients. Patients were randomly distributed into two groups: The control group received only an oral solution, whereas the other group received the oral solution plus a subcutaneous injection of 20 mg of butylscopolamine 10 min before the MR examination. Breath-hold T1-weighted gradient-recalled-echo (GRE) MR images were obtained in a 1.5-T superconductive unit. Quantitative image analysis was performed with region-of-interest (ROI) measurements of the signal intensity of the liver and in background air anterior and lateral to the patient. A qualitative analysis of the subjective quality of the T1-weighted images was also done, and the adverse reactions were registered. The groups were homogeneous regarding age, gender, and weight distribution. No significant differences in the signal intensity of the liver and in the incoherent noise measurements were found between the two groups. Gastrointestinal noise showed significant differences between groups, with lower values for the butylscopolamine group compared with the control group. There was also a statistically significant difference in the image quality between groups, and optimal studies were only found in the butylscopolamine group, where most patients had a good-quality evaluation. Regarding adverse events, there were non-significant differences between groups. In conclusion, administration of an antiperistaltic agent to reduce the movements of the gastrointestinal tract diminishes the motion artifacts generated on MR imaging of the abdomen, even at high field strength and with fast imaging sequences. Images of the upper abdomen obtained after pharmacologic suppression of the gastrointestinal movement are of significantly superior quality. (orig.)

  15. 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.

  16. Investigation of multichannel phased array performance for fetal MR imaging on 1.5T clinical MR system.

    Li, Ye; Pang, Yong; Vigneron, Daniel; Glenn, Orit; Xu, Duan; Zhang, Xiaoliang

    2011-01-01

    Fetal MRI on 1.5T clinical scanner has been increasingly becoming a powerful imaging tool for studying fetal brain abnormalities in vivo. Due to limited availability of dedicated fetal phased arrays, commercial torso or cardiac phased arrays are routinely used for fetal scans, which are unable to provide optimized SNR and parallel imaging performance with a small number coil elements, and insufficient coverage and filling factor. This poses a demand for the investigation and development of dedicated and efficient radiofrequency (RF) hardware to improve fetal imaging. In this work, an investigational approach to simulate the performance of multichannel flexible phased arrays is proposed to find a better solution to fetal MR imaging. A 32 channel fetal array is presented to increase coil sensitivity, coverage and parallel imaging performance. The electromagnetic field distribution of each element of the fetal array is numerically simulated by using finite-difference time-domain (FDTD) method. The array performance, including B(1) coverage, parallel reconstructed images and artifact power, is then theoretically calculated and compared with the torso array. Study results show that the proposed array is capable of increasing B(1) field strength as well as sensitivity homogeneity in the entire area of uterus. This would ensure high quality imaging regardless of the location of the fetus in the uterus. In addition, the paralleling imaging performance of the proposed fetal array is validated by using artifact power comparison with torso array. These results demonstrate the feasibility of the 32 channel flexible array for fetal MR imaging at 1.5T. PMID:22408747

  17. 7 Tesla (T) human cardiovascular magnetic resonance imaging using FLASH and SSFP to assess cardiac function: validation against 1.5 T and 3 T

    Suttie, J. J.; DelaBarre, L; Pitcher, A.; van de Moortele, P. F.; Dass, S; Snyder, C. J.; Francis, J M; Metzger, G. J.; Weale, P.; Ugurbil, K; Neubauer, S.; Robson, M; Vaughan, T

    2011-01-01

    We report the first comparison of cardiovascular magnetic resonance imaging (CMR) at 1.5 T, 3 T and 7 T field strengths using steady state free precession (SSFP) and fast low angle shot (FLASH) cine sequences. Cardiac volumes and mass measurements were assessed for feasibility, reproducibility and validity at each given field strength using FLASH and SSFP sequences. Ten healthy volunteers underwent retrospectively electrocardiogram (ECG) gated CMR at 1.5 T, 3 T and 7 T using FLASH and SSFP se...

  18. Signal intensity of motor and sensory cortices on T2-weighted and FLAIR images: intraindividual comparison of 1.5T and 3T MRI

    We compared the signal intensity of motor and sensory cortices on T2-weighted and FLAIR images obtained at 3T and 1.5T. MR images of 101 consecutive neurologically normal patients who underwent both 1.5T and 3T MRI were retrospectively evaluated. The signal intensities of motor and sensory cortices were analyzed both visually and quantitatively in comparison with superior frontal cortex. On T2-weighted images, decreased signal intensity of the motor cortex was seen in 6 (32%) of 19 patients aged 61-70 years and 14 (48%) of 29 at 71 years and older at 3T, compared with only 1 (5%) and 2 (7%) at 1.5T, respectively. On FLAIR images, the decreased signal intensity in the motor cortex was also more frequently seen at 3T than at 1.5T. The mean CNRs of motor and sensory cortices were significantly higher at 3T than at 1.5T on both T2-weighted and FLAIR images. The decreased signal intensity in the motor cortex was frequently seen at 3T compared with 1.5T. Knowledge of the finding at 3T can help the recognition of abnormalities of the motor cortex caused by various pathologic conditions. (orig.)

  19. Resin Permeation Through Compressed Glass Insulation for Iter Central Solenoid

    Reed, R.; Roundy, F.; Martovetsky, N.; Miller, J.; Mann, T.

    2010-04-01

    Concern has been expressed about the ability of the resin system to penetrate the compressed dry glass of the turn and layer insulation during vacuum-pressure impregnation of ITER Central Solenoid (CS) modules. The stacked pancake layers of each module result in compression loads up to 9×104 kg (100 tons) on the lowest layers of each segment. The objective of this program was to assess the effects of this compressive load on resin permeation under resin-transfer conditions and with materials identical to that expected to be used in actual coil fabrication [45-50 °C, vacuum of 133 Pa (1 torr), DGEBF/anhydride epoxy resin system, E-glass satin weave, applied pressure of 125 kPa]. The experimental conditions and materials are detailed and the permeation results presented in this paper.

  20. Performance analysis of the TOPAZ thin superconducting solenoid

    The TOPAZ Thin Superconducting Solenoid was designed and manufactured for the high energy colliding particle detector TOPAZ currently being built for the TRISTAN project in the National Laboratory for High Energy Physics. This magnet is required to make its thickness as thin as possible to minimize the resolution deterioration of the detector. The following analyses and actual tests were carried out to guarantee the performance of the magnet: (1) Analysis of structure strength, (2) Analysis of heat performance, (3) Analysis of ''Quench'', (4) Strength test of ''GFRP'' support rod, (5) Thermal conduction test of GFRP support rod. The results of the analyses were well in agreement with the actual cooldown and excitation test of the magnet which was made after completion of the fabrication. Effectiveness and reliability of the analysis techniques were demonstrated. (author)

  1. Conceptual fusion reactor designs based on the laser heat solenoid

    The feasibility of the laser heated solenoid (LHS) as an approach to fusion and fusion-fission commercial power generation has been examined. The LHS concept is based on magnetic confinement of a long slender plasma column which is partly heated by the axially directed beam from a powerful long wavelength laser. As a pure fusion concept, the LHS configurations studied so far are characterized by fairly difficult engineering constraints, particularly on the magnet, a large laser, and a marginally acceptable system energy balance. As a fusion-fission system, however, the LHS is capable of a very attractive energy balance, has much more relaxed engineering constraints, requires a relatively modest laser, and as such holds great potential as a power generator and fissile fuel breeding scheme

  2. Start-up of spherical tokamak without a center solenoid

    For low-aspect tokamak reactors, spherical tokamak reactors, ST-type FESF/CTFs, it is essential to remove or minimize a central solenoid (CS). Even with the minimized CS, non-inductive start up of the plasma current is required. Rapid increase in the spontaneous plasma current at the final stage of current start-up drives ignition. At the initial stage, formation of plasma and magnetic surfaces are required. As non-inductive plasma start-up scenarios, ECH/ECCD, LHCD, HHFW, DC HELICITY injection, plasma merging and NBI have been studied. In the present article, the present status and future prospect of experimental and theoretical works on these subjects. (author)

  3. Study of cosmics data tracks at Compact Muon Solenoid detector

    Heracleous, Natalie; Perieanu, Adrian [RWTH-Aachen, I. Physikalisches Institut Ib (Germany)

    2009-07-01

    An analysis of data taken in a Cosmic Run At Four Tesla (CRAFT) with the the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider will be presented. In this study, cosmic muons and their track components are analyzed. In CMS, the muon particle candidate can have an Inner and an Outer track component. The Inner track is reconstructed within the Tracker, while the Outer track in the Muon system. The Muon System provides muon identification and precise muon momentum resolution over a wide range. CRAFT data contain a large number of events with such reconstructed muons, O(10{sup 6}). Issues related to matching of the two muon track components are studied. Spectrum of transversal momentum and direction of high energetic muons are also presented.

  4. Construction of compact FEM using solenoid-induced helical wiggler

    A prototype of compact Free-Electron Maser (FEM) has been designed for the operation in a usual small laboratory which does not have electric source capacity available enough. The electron energy is 60-120 keV. As it is lower, stronger guiding magnetic field is necessary in addition to wiggler field. To fulfil this condition a solenoid-induced helical wiggler is applied from the viewpoint of saving the electric power of restricted source capacity. The wiggler, for example, with the period of 12 mm creates the field of 92 G in the guiding field of 3.2 kG. The whole system of FEM has been just constructed in a small-scale laboratory. It is so small to occupy the area of 0.7x2.9 m2

  5. A new generation of superconducting solenoids for heavy-ion linac application

    The beam dynamics of superconducting (SC) heavy-ion linacs operating in the velocity range below 0.4c require a compact accelerating-focusing lattice. The use of SC solenoids together with SC RF resonators within a common cryostat can solve the real-estate problem. The solenoids must have low fringe fields to avoid magnetic-flux capture in the SC RF resonators. Also, incorporating dipole steering coils together with the SC solenoids in one magnet assembly can increase the compactness of the linac lattice. R and D work has been carried out to determine the feasibility of combining the three elements of high solenoid field, low fringe field, and integral dipole field, into one compact package. A 9-Tesla magnet has been initially designed and will be prototyped, with the goal of eventually developing 14-Tesla solenoids of similar design. The most important design issues are: (1) to minimize stray field in the RF cavity region using SC bucking coils and (2) to achieve adequate mechanical stability of the transverse dipole windings in the presence of forces produced by the solenoid/bucking coil assembly. The assembly, including terminals, switches, and protection circuit, are designed to fit inside a 25-cm diameter helium reservoir. The results of the preliminary design of the solenoid, including numerical simulations of the beam dynamics, are reported

  6. A double pole-gap design for low spherical aberration in thin solenoids

    Chandran, Sona, E-mail: sona@rrcat.gov.in; Biswas, Bhaskar

    2015-10-21

    We here report a new design of a double air-slot or pole-gap type, axially thin, shielded solenoid with lower spherical aberration than conventional single pole-gap type solenoids. The net on-axis field from two optimally distanced pole gaps reduces the spherical aberration. The working principle of the model is also given by a pair of coaxial, in-air, identical current loops which can have lower spherical aberration than a single current loop. The new design is useful to achieve low spherical aberration in axially thin shielded solenoids.

  7. A double pole-gap design for low spherical aberration in thin solenoids

    We here report a new design of a double air-slot or pole-gap type, axially thin, shielded solenoid with lower spherical aberration than conventional single pole-gap type solenoids. The net on-axis field from two optimally distanced pole gaps reduces the spherical aberration. The working principle of the model is also given by a pair of coaxial, in-air, identical current loops which can have lower spherical aberration than a single current loop. The new design is useful to achieve low spherical aberration in axially thin shielded solenoids

  8. Gray matter-white matter contrast on spin-echo T1-weighted images at 3 T and 1.5 T: a quantitative comparison study

    Discrepancies exist in the literature regarding contrast between gray and white matter on spin-echo (SE) T1-weighted MR imaging at 3 T. The present study quantitatively assessed differences in gray matter-white matter contrast on both single- and multi-slice SE T1-weighted imaging between 3 and 1.5 T. SE T1-weighted sequences with the same parameters at both 3 and 1.5 T were used. Contrast-to-noise ratio (CNR) between gray and white matter (CNRGM-WM) was evaluated for both frontal lobes. To assess the effects of interslice gap, multi-slice images were obtained with both 0 and 25% interslice gap. Single-slice CNRGM-WM was higher at 3 T (17.66 ± 2.68) than at 1.5 T (13.09 ± 2.35; P GM-WM of multi-slice images with 0% gap was noted between 3 and 1.5 T (3T, 8.61 ± 2.55; 1.5T, 7.43 ± 1.20; P > 0.05). Multi-slice CNRGM-WM with 25% gap was higher at 3T (12.47 ± 3.31) than at 1.5 T (9.73 ± 1.37; P GM-WM reduction rate of multi-slice images with 0% gap compared with single-slice images was higher at 3T (0.47 ± 0.13) than at 1.5 T (0.38 ± 0.09; P = 0.02). CNRGM-WM on single-slice SE T1-weighted imaging and CNRGM-WM on multi-slice images with 25% interslice gap were better at 3 T than at 1.5 T. The influence of multi-slice imaging on CNRGM-WM was significantly larger at 3T than at 1.5 T. (orig.)

  9. 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.

  10. Pelvimetry and patient acceptability compared between open 0.5-T and closed 1.5-T MR systems

    Our objective was to compare maternal pelvimetry and patient acceptability between open low-field (0.5-T) and closed 1.5-T MR systems. Thirty women referred for pelvimetry (pregnant: n=15) were scanned twice in the supine position, once in the vertical open system and once in the closed system. Each patient completed a comfort and acceptability questionnaire. Pelvimetric and questionnaire data were compared between systems. Total scan time was double in the open system (7:52±1:47 vs 3:12±1:20 min). Poor image quality in the open system prevented assessment of interspinous and intertuberous diameters in one woman and all measurements in another, both pregnant, with abdominal circumferences >120 cm. The open system was much more acceptable in terms of claustrophobia and confinement (both p<0.01). Claustrophobia interrupted one closed examination. Thirty-three percent of pregnant women in both systems reported fear of fetal harm. Sixty percent of all women preferred the open system, 7% the closed system, and 33% had no preference. Limits of agreement of 3-5% from the mean for all diameters confirmed good pelvimetric reproducibility. Women's preference for open-system MR pelvimetry is feasible with abdominal circumferences ≤120 cm. (orig.)

  11. In vivo imaging of transplanted hepatocytes with a 1.5-T clinical MRI system - initial experience in mice

    The feasibility of in vitro mature mouse hepatocyte labeling with a novel iron oxide particle was assessed and the ability of 1.5-T magnetic resonance imaging (MRI) to track labeled mouse hepatocytes in syngenic recipient livers following intraportal cell transplantation was tested. Mouse hepatocytes were incubated with anionic iron oxide nanoparticles at various iron concentrations. Cell viability was assessed and iron oxide particle uptake quantified. Labeled hepatocytes were intraportally injected into 20 mice, while unlabeled hepatocytes were injected into two mice. Liver T2 values, spleen-to-muscle relative signal intensity (RIspleen/muscle), and liver-to-muscle relative signal intensity (RIliver/muscle) on gradient-echo T2-weighted imaging after injection of either labeled or unlabeled hepatocytes were compared with an ANOVA test followed by Fisher's a posteriori PLSD test. Livers, spleens and lungs were collected for histological analysis. Iron oxide particle uptake was saturable with a maximum iron content of 20 pg per cell and without viability alteration after 3 days of culture. Following labeled-cell transplantation, recipient livers showed well-defined nodular foci of low signal intensity on MRI - consistent with clusters of labeled hepatocytes on pathological analysis - combined with a significant decrease in both liver T2 values and liver-to-muscle RIliver/muscle (P = 0.01) with minimal T2 values demonstrated 8 days after transplantation. Conventional MRI can demonstrate the presence of transplanted iron-labeled mature hepatocytes in mouse liver. (orig.)

  12. Artifacts in MRI of the temporomandibular joint caused by dental alloys: a phantom study at 1.5 T

    Purpose: The influence of dental alloys on MRI of the temporomandibular joint was studied using a phantom model for this joint. Methods: At 1,5 T, 15 dental alloys and 14 of their most important components were investigated acquiring sagittal (FOV: 150 mm) and transverse (FOV: 250 mm) T1-weighted SE additionally. The artifacts were assessed qualitatively as well as quantitatively, and the samples were subdivided into four artifact categories. Results: Ag, Cu, Ga, In, Ti, Sn, Zn, amalgan, the precious alloys, the Au-Pd and Ag-Pd alloys showed no artifacts (category I). Minimal artifacts below 10 mm on transverse images (category II) were found for Cr, Pd, Pt and for the Ni-Cr alloy. Mn and the remaining non-precious alloys induced artifacts up to 30 mm (category III). Significant artifacts - more than 30 mm - (category IV) were to be more susceptible for artifacts than T1-weighted SE and FLASH techniques. Conclusions: In contrast to dental alloys for fixed prosthodontics, Ni-Cr- or 18/8 wires used for orthodontic bands can influence not only the image quality, but also the diagnostic reliability of MRI of the temporomandibular joint. (orig.)

  13. Value of magnetic resonance mammographic at 1.5 T in the differential diagnosis of mastitis versus inflammatory carcinoma

    Purpose: The distinction between mastitis and inflammatory breast carcinoma is an important one. Current methods of evaluation including mammography, ultrasound and clinical examination do not enable this distinction. Dynamic magnetic resonance mammography (MRM) is a study with potential in this regard. Material and methods: 12 patients, in whom clinical examination, mammography and ultrasound could not distinguish between both diseases, were reviewed retrospectively by means of MRM using a 1.5 T Siemens Magnetom SP and a circular mamma coil. We used dynamic 3-D gradient echo sequences with a duration of one minute. Results: At present MRM cannot definitely distinguish between mastitis and inflammatory carcinoma, 80% of the inflammatory carcinomas were found to enhance more than 100% in the first minute, compared to 43% for mastitis. No other differences were seen. Conclusion: MRM proved useful in the follow-up of treated mastitis to demonstrate the success of antibiotic treatment of mastitis and to diagnose a histologically unconfirmed inflammatory carcinoma by means of a different follow-up. (orig.)

  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. 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

    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

  16. Design of new superconducting central solenoid of SST-1 tokamak

    The key role of the central solenoid (CS) magnet of a Tokamak is for gas breakdown, ramp up and maintaining of plasma current for longer duration. The magnetic flux change in CS along with other PF coils generates magnetic null and induces electric field in toroidal direction. The induced toroidal electric field accelerates the residual electrons which collide with the neutrals and an avalanche takes place which led to the net plasma in the vacuum vessel of a Tokamak. In order to maximize the CS volt-sec capability, the higher magnetic field with a greater magnetic flux linkage is necessary. In order to facilitate all these requirements of SST-1 a new superconducting CS has been designed for SST-1. The design of new central solenoid has two bases; first one is physics and second is smart engineering in limited bore diameter of ∼655 mm. The physics basis of the design includes volt-sec storage capacity of ∼0.8 volt-sec, magnetic field null around 0.2 m over major radius of 1.1 m and toroidal electric field of ∼0.3 volt/m.The engineering design of new CS consists of Nb3Sn cable in conduit conductor (CICC) of operating current of 14 kA @ 4.5 K at 6 T, consolidated winding pack, smart quench detection system, protection system, housing cryostat and conductor terminations and joint design. The winding pack consists of 576 numbers of turns distributed in four layers with 0.75 mm FRP tape soaked with cyanide Easter based epoxy resin turn insulation and 3 mm of ground insulation. The inter-layer low resistance (∼1 nΩ) at 14 kA @ 4.5 K terminal praying hand joints has been designed for making winding pack continuous. The total height of winding pack is 2500 mm. The stored energy of this winding pack is ∼3 MJ at 14 kA of operating current. The expected heat load at cryogenic temperature is ∼10 W per layer, which requires helium mass flow rate of 1.4 g/s at 1.4 bars @ 4.5 K. The typical diameter and height of housing cryostat are 650 mm and 2563 mm with 80 K

  17. Design and analysis of direct action solenoid valve based on computational intelligence

    Liu Qianfeng, E-mail: liuqianfeng@gmail.co [Institute of Nuclear and New Energy Technology, Tsinghua University, Key Laboratory of Advanced Reactor Engineering and Safety of the Ministry of Education, Beijing 100084 (China); Bo Hanliang; Qin Benke [Institute of Nuclear and New Energy Technology, Tsinghua University, Key Laboratory of Advanced Reactor Engineering and Safety of the Ministry of Education, Beijing 100084 (China)

    2010-10-15

    Control Rod Hydraulic Drive Mechanism (CRHDM) is a newly invented patent of the Institute of Nuclear and New Energy Technology Tsinghua University which owns CRHDM's independent intellectual property rights while the integrated valve made up of three direct action solenoid valves is the key part of this mechanism. Therefore, the performance of the solenoid valve affects the integrated valve and the CRHDM directly. In this paper, we present a method to design the parameters of the direct action solenoid valve based on orthogonal experiment design, back propagation (BP) neural network and particle swarm optimization (PSO). The result proves that the method is feasible and accurate to design the parameters in order to obtain the biggest electromagnetic force. Besides, the result also shows that it is the current which influences the electromagnetic force of the direct action solenoid valve most.

  18. Design features of the solenoid magnets for the central cell of the MFTF-B

    The 14 superconducting solenoid magnets which form the central cell of the MFTF-B are being designed and fabricated by General Dynamics for the Lawrence Livermore National Laboratory. Each solenoid coil has a mean diameter of five meters and contains 600 turns of a proven conductor type. Structural loading resulting from credible fault events, cooldown and warmup requirements, and manufacturing processes consistent with other MFTF-B magnets have been considered in the selection of 304 LN as the structural material for the magnet. The solenoid magnets are connected by 24 intercoil beams and 20 solid struts which resist the longitudinal seismic and electromagnetic attractive forces and by 24 hanger/side supports which react magnet dead weight and seismic loads. A modular arrangement of two solenoid coils within a vacuum vessel segment allow for sequential checkout and installation

  19. 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...

  20. Design and analysis of direct action solenoid valve based on computational intelligence

    Control Rod Hydraulic Drive Mechanism (CRHDM) is a newly invented patent of the Institute of Nuclear and New Energy Technology Tsinghua University which owns CRHDM's independent intellectual property rights while the integrated valve made up of three direct action solenoid valves is the key part of this mechanism. Therefore, the performance of the solenoid valve affects the integrated valve and the CRHDM directly. In this paper, we present a method to design the parameters of the direct action solenoid valve based on orthogonal experiment design, back propagation (BP) neural network and particle swarm optimization (PSO). The result proves that the method is feasible and accurate to design the parameters in order to obtain the biggest electromagnetic force. Besides, the result also shows that it is the current which influences the electromagnetic force of the direct action solenoid valve most.

  1. Proceedings of the international workshop on solenoidal detectors for the SSC

    This issue is the collection of the papers presented at the International Workshop on solenoidal detectors for the Superconducting Super Collider (SSC). The 48 of the presented papers are indexed individually. (J.P.N.)

  2. Scan rescan and intra-observer variability of magnetic resonance imaging of carotid atherosclerosis at 1.5 T and 3.0 T

    Vidal, Arvin; Bureau, Yves; Wade, Trevor; Spence, J. David; Rutt, Brian K.; Fenster, Aaron; Parraga, Grace

    2008-12-01

    Carotid atherosclerosis measurements for eight subjects at baseline and 14 ± 2 days later were examined using 1.5 T and 3.0 T magnetic resonance imaging (MRI). A single observer blinded to field strength, subject and timepoint manually segmented carotid artery wall and lumen boundaries in randomized images in five measurement trials. Mean increases in the signal-to-noise ratios (SNR) for T1-weighted images acquired at 3.0 T compared to 1.5 T were 90% (scan) and 80% (rescan). Despite significantly improved SNR and contrast-to-noise ratios (CNR) for images acquired at 3.0 T, vessel wall volume (VWV) intra-observer variability was not significantly different using coefficients of variation (COV), and intraclass correlation coefficients (ICC). VWV interscan variability and consistency at both field strengths were not statistically different (1.5 T/3.0 T COV = 5.7%/7.8%, R2 = 0.96 for 1.5 T and R2 = 0.87 for 3.0 T). A two-way analysis of variance showed a VWV dependence on field strength but not scan timepoint. In addition, a paired t-test showed significant differences in VWV measured at 3.0 T as compared to 1.5 T. These results suggest that although images acquired at 1.5 T have lower SNR and CNR VWV, measurement variability was not significantly different from 3.0 T VWV and that VWV is field-strength dependent which may be an important consideration for longitudinal studies.

  3. Development of power supply and programmer for superconducting solenoid magnet

    A current and voltage regulated (0-100A / 0-10V) switch mode power supply and its programmer have been designed and developed, to power the super conducting solenoid magnets used as a transverse focusing devices inside the superconducting LINAC module, and other offline superconducting magnet setups. The power supply and programmer are two independent units. The power supply is controlled by the programmer when it is used to power the superconducting magnet, but with other loads it can be used without the programmer. The programmer is designed as a special feed back loop element, which compensates the effect of large inductance and zero resistance of super conducting magnet to ensure oscillation free smooth operation. The programmer has special features like quench protection, magnet current ramp rate control and maximum limit settings of magnet current and voltage. The power supply alone (without programmer) can be used for other laboratory applications requiring regulated variable DC voltage and current source. These power supplies can be used in master-slave mode to get several kW of power. This set-up (supply and programmer) have both manual and computer control features. (author)

  4. Assessment of diagnostic methods for solenoid-operated valves

    Solenoid-operated valves (SOVS) were studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary objective of the study was to identify, evaluate, and recommend methods for inspection, surveillance, monitoring, and maintenance of SOVs that can help ensure their operational readiness-that is, their ability to perform required safety functions under all anticipated operating conditions, since failure of one of these small and relatively inexpensive devices could have serious consequences under certain circumstances. An earlier (Phase 1) NPAR program study described SOV failure modes and causes and identified measurable parameters thought to be linked to the progression of ever-present degradation mechanisms that may ultimately result in functional failure of the valve. Using this earlier work as a guide, the present (Phase II) study focused on devising and then demonstrating the effectiveness of techniques and equipment with which to measure performance parameters that show promise for detecting the presence and trending the progress of such degradations before they reach a critical stage. Intrusive techniques requiring the addition of magnetic or acoustic sensors or the application of special test signals were investigated briefly, but major emphasis was placed on the examination of condition-indicating techniques that can be applied with minimal cost and impact on plant operation. Experimental results are presented that demonstrate the technical feasibility and practicality of the monitoring techniques assessed in the study, and recommendations for further work are provided

  5. 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.

  6. Laser beam-plasma coupling in laser solenoid plasmas

    A model has been constructed to analyze the gross beam-plasma interaction in a laser solenoid plasma. The model includes a simple solution for a slab plasma response to a given laser beam, and a solution for axial beam size variations in response to arbitrary axial plasma structure. The two solutions are combined to determine the coupled behavior. Trapping of the focused laser beam where it enters the plasma is a significant problem, but can be achieved by a minimum level of imbedded field in the plasma. If the beam is trapped, it first focuses and then defocuses near the front of the bleaching wave (front of the laser heated plasma). In order to avoid divergence of the beam near the front, it is essential to have a pre-formed favorable density profile in the plasma. Such a condition is probably achieved automatically in the early stages of plasma heating. Several techniques are discussed which can be used to avert unfavorable refractive behavior (catastrophic self-focusing and defocusing)

  7. Fusion reactor development scenarios for the laser solenoid concept

    A program is described which overcomes some size problems by utilizing the fusion-fission hybrid or symbiotic technology to produce fuel for the installed LWR capacity, eliminating reliance on early fusion reactors for base load power, and taking advantage of the reduced technological demands of the fusion-fission hybrid to allow earlier introduction of these systems. The use of the fusion-fission hybrid to breed fuel for the LWR economy not only takes advantage of a very effective breeder, but also combines the technological development of the breeder and fusion power into a single, more cost effective program. Once a fusion hybrid breeder economy is established, the advent of pure fusion power will involve a much smaller, relatively risk-free technological development. The proposed program is demonstrated by a series of conceptual designs using the laser solenoid fusion concept as an example. It will be shown that the fusion-fission hybrid power plant is a project whose engineering requirements appear quite reachable at the present time and that with better knowledge of the physics and technology, smaller fusion power plants which have very attractive characteristics for the utility industry should be possible at a later time

  8. The EVA trigger: Transverse momentum selection in a solenoid

    A custom CMOS LSI and ECL PAL-based trigger system for a particle physics experiment is presented. The EVA apparatus at Brookhaven National Laboratory is designed to observe large angle scattering near the kinematic limit of pT for hadron-proton scattering with cross sections in the picobarn range and interaction rates of 100 MHz. The trigger selects events with high pT tracks in a solenoidal straw tube tracking magnetic spectrometer in three stages. An ECL PAL scintillation hodoscope pretrigger and timing mask is followed by pT reconstruction from three superlayers of straw tube drift chambers using custom CMOS LSI integrated circuits. The higher level CMOS trigger system is implemented on custom modules and functions at secondary trigger rates in excess of 1 MHz. A Motorola MC68000 microprocessor resides on each module and uses global information on the event to provide a third trigger level. The modules are interfaced to VMEbus, controlled by a single board VME computer. ((orig.))

  9. Design of a tracking system for a solenoidal detector

    The goals of a tracking system for the SSC are to provide momentum measurement and a fast trigger for charged particles with pT above a few GeV/c and |η| ≤ 2.5. In addition, the tracking system should provide a precise vertex measurement in order to identify long-lived tracks, for example, from B decays, and detect separated vertices from multiple p-p interactions. Since the tracking system is only a part of the complete detector, it must provide these functions in an economical manner. The tracking system must operate in the high-rate environment of the SSC at and above the design luminosity. The design of an integrated tracking system for a solenoidal detector will be presented. The tracking system consists of a silicon pixel and microstrip detector at smaller radii from the beam collision point and wire chambers at larger radii. The tracking system provides momentum measurements and a fast trigger for all charged particles with pT above a few GeV/c and for |η| ≤ 2.5. Research and development issues will be discussed

  10. Conceptual design report for the Solenoidal Tracker at RHIC

    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 Δp/p ∼ 0.02 at p = 0.1 GeV/c is required to accomplish the physics, and,Δp/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

  11. Compressive vs Solenoidal Turbulence and Violent Disc Instability

    Mandelker, Nir; Dekel, Avishai; Inoue, Shigeki; Ceverino, Daniel; Primack, Joel

    2015-08-01

    High redshift star-forming galaxies (SFGs) exhibit star-formation rates (SFR) 20-100 times higher than local SFGs. This increased SFR is due to much higher gas fractions and surface densities prevalent in high redshift SFG. Such high gas fractions cause the disc to become violently unstable and undergo a phase of violent disc instability (VDI). During the VDI phase, there is rapid inflow of gas towards the galactic centre with inflow times comparable to the disc orbital time, which can lead to a compact "blue nugget". In addition, giant ~kpc scale star-forming clumps are formed, the most massive of which survive dtellar feedback and migrate towards the centre, where they coalesce in the growing bulge. While the existence of giant clumps is commonly associated with Toomre instability, high resolution cosmological simulations of galaxy formation show that active clump formation occurs even in regions where the Toomre Q parameter is well above the threshold for stability. The simulations suggest instead a non-linear instability, where frequent minor mergers and intense inflow by cold streams increase the compressive mode of turbulence relative to the solenoidal mode. We find this can induce clump formation even in regions that should be stable according to linear Toomre theory. Thus we show that mergers, smooth accretion from the cosmic web and VDI all go hand in hand in driving galaxy evolution at high redshift.

  12. Inservice diagnostic methods for solenoid-operated valves

    Solenoid-operated valves (SOVs) were studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary objective of the study was to identify, evaluate, and recommend methods for inspection, surveillance, monitoring, and maintenance of SOVs that can help ensure their operational readiness-that is, their ability to perform required safety functions under all anticipated operating conditions, since failure of one of these small and relatively inexpensive devices could have serious consequences under certain circumstances. An earlier (Phase 1) NPAR program study described SOV failure modes and causes and had identified measurable parameters thought to be linked to the progression of everpresent degradation mechanisms that may ultimately result in functional failure of the valve. Using this earlier work as a guide, the present (Phase 11) study focused on devising and then demonstrating the effectiveness of techniques and equipment with which to measure performance parameters that show promise for detecting the presence and trending the progress of such degradations before they reach a critical stage. Intrusive techniques requiring the addition of magnetic or acoustic sensors or the application of special test signals were investigated briefly, but major emphasis was placed on the examination of condition-indicating techniques that can be applied with minimal cost and impact on plant operation. Experimental results are presented that demonstrate the technical feasibility and practicality of the monitoring techniques assessed in the study, and recommendations for further work are provided

  13. Testing of ITER central solenoid coil insulation in an array

    A glass-polyimide insulation system has been proposed by the US team for use in the Central Solenoid (CS) coil of the international Thermonuclear Experimental Reactor (ITER) machine and it is planned to use this system in the CS model coil inner module. The turn insulation will consist of 2 layers of combined prepreg and Kapton. Each layer is 50% overlapped with a butt wrap of prepreg and an overwrap of S glass. The coil layers will be separated by a glass-resin composite and impregnated in a VPI process. Small scale tests on the various components of the insulation are complete. It is planned to fabricate and test the insulation in a 4 x 4 insulated CS conductor array which will include the layer insulation and be vacuum impregnated. The conductor array will be subjected to 20 thermal cycles and 100000 mechanical load cycles in a Liquid Nitrogen environment. These loads are similar to those seen in the CS coil design. The insulation will be electrically tested at several stages during mechanical testing. This paper will describe the array configuration, fabrication: process, instrumentation, testing configuration, and supporting analyses used in selecting the array and test configurations

  14. The LHC Compact Muon Solenoid experiment Detector Control System

    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). The CMS detector control system (DCS) ensures a safe, correct and efficient operation of the detector so that high quality physics data can be recorded. The system is also required to operate the detector with a small crew of experts who can take care of the maintenance of its software and hardware infrastructure. The subsystems size sum up to more than a million parameters that need to be supervised by the DCS. 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 a division between its computing resources and functionality by creating a computing framework allowing plugging in of functional components. DCS components are developed by the subsystems expert groups while the computing infrastructure is developed centrally. To ensure the correct operation of the detector, DCS organizes the communication between the accelerator and the experiment systems making sure that the detector is in a safe state during hazardous situations and is fully operational when stable conditions are present. This paper describes the current status of the CMS DCS focusing on operational aspects and the role of DCS in this communication.

  15. Conduction cooled magnet design for 1.5 T, 3.0 T and 7.0 T MRI systems

    Main magnets for magnetic resonance imaging (MRI) are largely constructed with low temperature superconducting material. Most commonly used superconductors for these magnets are niobium-titanium (NbTi). Such magnets are operated at 4.2 K by being immersed in a liquid helium bath for long time operation. As the cost of liquid helium has increased threefold in the last decade and the market for MRI systems is on average increasing by more than 7% every year, there is a growing demand for an alternative to liquid helium. Superconductors such as magnesium-diboride (MgB2) and niobium-tin (Nb3Sn) demonstrate superior current carrying quality at higher critical temperatures than 4.2 K. In this article, electromagnetic designs for conduction cooled main magnets over the range of medium field strengths (1.5 T) to ultrahigh field strengths (7.0 T) are presented. These designs are achieved by an improved functional approach coming from a series of developments by the present research group and using properties of the state-of-the-art second generation MgB2 wires and Nb3Sn wires developed by Hyper Tech Research Inc. The MgB2 magnet designs operated at different field strengths demonstrate excellent homogeneity and shielding properties at an operating temperature of 10 K. At ultrahigh field, the high current density on Nb3Sn allowed by the larger magnetic field on wire helps to reduce the superconductor volume in comparison with high field NbTi magnet designs. This allows for a compact magnet design that can operate at a temperature of 8 K. Overall, the designs created show promise in the development of conduction cooled dry magnets that would reduce dependence on helium. (paper)

  16. Rapid-sequence phosphorus-31 magnetic resonance spectroscopy of the human heart using a 1.5-T clinical system

    Chida, K.; Saito, H.; Nagasaka, T.; Otani, H.; Kohzuki, M.; Zuguchi, M. [Tohoku Univ., Sendai (Japan). Dept. of Radiological Technology

    2004-02-01

    To compare a 'standard' slow phosphorus-31 magnetic resonance spectroscopy (31P-MRS) sequence with two faster sequences in phantoms and healthy volunteers using a 1.5-T clinical system. Complete 3D localization was performed using a 2D phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. Two 31P-MRS rapid sequences (RS8-4: 8 x 8 phase-encoding, with an average of 4 acquisitions, and RS16-1: 16 x 16 phase-encoding, 1 acquisition) were compared with the standard sequence (StdP: 16 x 16 phase-encoding, with an average of 8 acquisitions) in phantom and healthy volunteers. Acquisition time for the 31P-MRS procedure with StdP, RS8-4, and RS16-1 in the healthy volunteer studies ranged from 30 to 45, 3 to 5, and 3 to 5 minutes, respectively. Metabolite measurements of healthy volunteers obtained from 31P-MRS using RS8-4 correlated with values obtained using StdP (PCr r2=0.63, P<0.001; ATP r=0.41, P<0.01 and PCr/ATP ratio r2=0.25, P<0.05). There was no correlation between StdP and RS16-1 for either ATP or the PCr/ATP ratio (r2=0.03, P=0.60, and r2=0.11, p=0.26, respectively). Reproducibility (intensity of phosphorus signal) with RS16-1 was worse than that of RS8-4 or StdP. 31P-MRS using RS8-4 may be a valid diagnostic tool for patients with cardiac diseases.

  17. Localized single-voxel spin-echo proton MR spectroscopy of normal hippocampal area at 1.5T

    To determine the optimal voxel volume covering the hippocampal area in single-voxel proton magnetic resonance (MR) spectroscopy and to evaluate the reproducibility of metabolite ratios of the spectra. Localized single-voxel proton proton MR spectroscopy was applied to the right hippocampal area of five healthy volunteers at 1.5T(Siemens Vision), using a standard head coil, and we employed the spin-echo or point resolved spectroscopy sequence. Voxel volume was changed from 1 ml to 5 ml but other operator-dependent measurement parameters were fixed, as follows: repetition time/echo time=1500/135 msec, number of scans=300. Using the same voxel volume, five consecutive measurements were obtained in each subject. Singal to noise ratio(SNR) of N-acetylaspartate(NAA), NAA/Choline containing compounds(Cho) and NAA/Cr(creatine and phosphocreatine)+Cho ratios were calculated for all 25 spectra. The SNR of NAA peaks increased significantly as voxel volume was increased to 3 ml (p0.1); in those obtained with voxel volume of 2-4 ml, the standard deviations of NAA/Cho (10.6-13.2% of mean values) were similar to those of NAA/Cr+Cho(8.5-13.2% of mean values). For spin-echo proton MR spectroscopy of the hippocampal area, the optimal voxel volume may be more than 3 ml in a setting of TR/TE=1500/135 msec and number of scans=300. In this situation, standard deviations of metabolite ratios may reach about 8-13% of mean values

  18. Whistler Wave Excitation and Effects of Self-Focusing on Ion Beam Propagation through a Background Plasma along a Solenoidal Magnetic Field

    Mikhail, Dorf A.; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.

    2010-02-02

    This paper extends studies of ion beam transport through a background plasma along a solenoidal magnetic field [I. Kaganovich et al., Phys. Plasmas 15, 103108 (2008)] to the important regime of moderate magnetic field strength satisfying ωce > 2βbωpe . Here, ωce and ω pe are the electron cyclotron frequency and electron plasma frequency, respectively, and βb = vb/ c is the directed ion beam velocity normalized to the speed of light. The electromagnetic field perturbations excited by the ion beam pulse in this regime are calculated analytically, and verified by comparison with the numerical simulations. The degrees of beam charge neutralization and current neutralization are estimated, and the transverse component of the Lorentz force associated with the excited electromagnetic field is calculated. It is found that the plasma response to the ion beam pulse is significantly different depending on whether the value of the solenoidal magnetic field is below or above the threshold value specified by ω cr ce = 2βbωpe, and corresponding to the resonant excitation of large-amplitude whistler waves. The use of intense whistler wave excitations for diagnostic purposes is also discussed.

  19. Whistler Wave Excitation and Effects of Self-Focusing on Ion Beam Propagation through a Background Plasma along a Solenoidal Magnetic Field

    This paper extends studies of ion beam transport through a background plasma along a solenoidal magnetic field (I. Kaganovich et al., Phys. Plasmas 15, 103108 (2008)) to the important regime of moderate magnetic field strength satisfying ωce > 2βbωpe. Here, ωce and ωpe are the electron cyclotron frequency and electron plasma frequency, respectively, and βb = vb/c is the directed ion beam velocity normalized to the speed of light. The electromagnetic field perturbations excited by the ion beam pulse in this regime are calculated analytically, and verified by comparison with the numerical simulations. The degrees of beam charge neutralization and current neutralization are estimated, and the transverse component of the Lorentz force associated with the excited electromagnetic field is calculated. It is found that the plasma response to the ion beam pulse is significantly different depending on whether the value of the solenoidal magnetic field is below or above the threshold value specified by ωcecr = 2βbωpe, and corresponding to the resonant excitation of large-amplitude whistler waves. The use of intense whistler wave excitations for diagnostic purposes is also discussed.

  20. Metastability Exchange Optical Pumping of Helium-3 at High Pressures and 1.5 T: Comparison of two Optical Pumping Transitions

    Abboud, Marie; Sinatra, Alice; Tastevin, Geneviève; Nacher, Pierre-Jean; Maître, Xavier

    2005-01-01

    4 pages; proceeding 13th international laser physics workshop LasPhys'04, Trieste, July 12-16 2004 At low magnetic field, metastability exchange optical pumping of helium-3 is known to provide high nuclear polarizations for pressures around 1 mbar. In a recent paper, we demonstrated that operating at 1.5 T can significantly improve the results of metastability exchange optical pumping at high pressures. Here, we compare the performances of two different optical pumping lines at 1.5 T, and ...

  1. Magnet system for a laser heated solenoid fusion reactor

    A hybrid magnet system is proposed that consists of a 2 m inside diameter 20 T continuous superconducting magnet surrounding a number of 4 cm bore, 20 T pulsed magnets. Each pulsed magnet encloses a plasma tube for the laser heated fusion reaction. A tritium breeder, heat exchanger, and neutron shield are located in the annular region between the pulsed magnets and the superconducting magnet. The overall length of the system is 1 kilometer. The pulsed magnets are operated in a reverse-forward current sequence so that the magnetic field in the plasma is first reduced to zero and then raised to 40 T. Novel design features are included in the pulsed magnets, pulsing circuits and the superconducting magnet. Of particular interest is the structural design which maintains practical stress levels for readily available materials in both magnets and enables operation of the superconductors in a strain-free condition. Estimated costs and comment on the advantages of the pressure support system are presented

  2. The ESRF Miniature Pulsed Magnetic Field System

    van der Linden, Peter J. E. M.; Strohm, Cornelius; Roth, Thomas; Detlefs, Carsten; Mathon, Olivier

    2010-06-01

    We have developed a portable system to provide pulsed magnetic fields on the ESRF X-ray beamlines. The complete system consists of a power supply, liquid Helium and liquid Nitrogen dewars with a siphon each, control electronics and a double cryostat for separate coil and sample cooling. The liquid nitrogen cooled solenoids reach a maximum field of 30 Tesla for a total pulse duration of one milisecond. They are constructed for optimised cooling rate after the pulse to obtain a high duty cycle, the repetition rate is five pulses per minute at maximum field. The sample is cooled in an independent Helium flow cryostat which is inserted into the bore of the magnet. The flow cryostat has a temperature range from 5 to 250 Kelvin with a direct contact between the sample and Helium flow. This overview gives a general presentation of the system and we will show recent results.

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

    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 (B1) 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

  4. Silicon subsystem mechanical engineering work for the solenoidal detector collaboration

    Miller, W.O.; Barney, M.; Byrd, D.; Christensen, R.W.; Dransfield, G.; Elder, M.; Gamble, M.; Crastataro, C.; Hanlon, J.; Jones, D.C. [and others

    1995-02-01

    The silicon tracking system (STS) for the Solenoidal Detector Collaboration (SDC) represented an order of magnitude increase in size over any silicon system that had been previously built or even planned. In order to meet its performance requirements, it could not simply be a linear scaling of earlier systems, but instead required completely new concepts. The small size of the early systems made it possible to simply move the support hardware and services largely outside the active volume of the system. For a system five meters long, that simply is not an option. The design of the STS for the SDC experiment was the result of numerous compromises between the capabilities required to do the physics and the limitations imposed by cost, material properties, and silicon strip detector characteristics. From the point of view of the physics, the silicon system should start as close to the interaction point as possible. In addition, the detectors should measure the position of particles passing through them with no errors, and should not deflect or interact with the particles in any way. However, cost, radiation damage, and other factors limiting detector performance dictated, other, more realistic values. Radiation damage limited the inner radius of the silicon detectors to about 9 cm, whereas cost limited the outer radius of the detectors to about 50 cm. Cost also limits the half length of the system to about 250 cm. To control the effects of radiation damage on the detectors required operating the system at a temperature of 0{degrees}C or below, and maintaining that temperature throughout life of the system. To summarize, the physics and properties of the silicon strip detectors requires that the detectors be operated at or below 0{degrees}C, be positioned very accurately during assembly and remain positionally stable throughout their operation, and that all materials used be radiation hard and have a large thickness for one radiation length.

  5. 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.

  6. AC loss calculation of central solenoid model coil

    The AC loss of Central Solenoid Model Coil of ITER 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. In Part A the theory is summarized essential to present calculation. This covers a semianalytical integral formulation to calculate the magnetic field distribution in the cross-section of a coil and also 2D and 3D differential formulations for eddy current calculation of jackets and structural steel components, respectively. In Part B the conditions and results of calculation are described in detail. Losses are calculated separately in different components. Also the different types of losses are separated, and only one of the followings is considered in the same time; eddy current loss, ferromagnetic hysteresis loss, superconducting hysteresis loss, coupling loss. The followings are concluded. The coupling loss was found to be the largest 83% of the total AC loss supposing 50 msec characteristic time constant. Also significant amount of heat is generated in structural steels, cooling is required for stainless steel structural components. The loss of joints is not large, however concentrated, therefore joints should receive attention. Specially Lap-type joints are critical components. The eddy current and coupling power losses can be significantly decreased by increasing the ramp-up time since they are proportional to the square of flux change rate, while superconducting and ferromagnetic hysteresis power losses decrease linearly with decreasing flux change rate. Joule losses are produced in joints even after the energizing process of the magnet, when it is driven by a constant excitation current. This propose us to keep the time of full power operation short. (J.P.N.)

  7. Silicon subsystem mechanical engineering work for the solenoidal detector collaboration

    The silicon tracking system (STS) for the Solenoidal Detector Collaboration (SDC) represented an order of magnitude increase in size over any silicon system that had been previously built or even planned. In order to meet its performance requirements, it could not simply be a linear scaling of earlier systems, but instead required completely new concepts. The small size of the early systems made it possible to simply move the support hardware and services largely outside the active volume of the system. For a system five meters long, that simply is not an option. The design of the STS for the SDC experiment was the result of numerous compromises between the capabilities required to do the physics and the limitations imposed by cost, material properties, and silicon strip detector characteristics. From the point of view of the physics, the silicon system should start as close to the interaction point as possible. In addition, the detectors should measure the position of particles passing through them with no errors, and should not deflect or interact with the particles in any way. However, cost, radiation damage, and other factors limiting detector performance dictated, other, more realistic values. Radiation damage limited the inner radius of the silicon detectors to about 9 cm, whereas cost limited the outer radius of the detectors to about 50 cm. Cost also limits the half length of the system to about 250 cm. To control the effects of radiation damage on the detectors required operating the system at a temperature of 0 degrees C or below, and maintaining that temperature throughout life of the system. To summarize, the physics and properties of the silicon strip detectors requires that the detectors be operated at or below 0 degrees C, be positioned very accurately during assembly and remain positionally stable throughout their operation, and that all materials used be radiation hard and have a large thickness for one radiation length

  8. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    Gerretsen, S.C.; Versluis, B.; Bekkers, S.C.A.M. [Maastricht University Hospital, Department of Radiology, Maastricht (Netherlands); Leiner, T. [Maastricht University Hospital, Department of Radiology, Maastricht (Netherlands)], E-mail: leiner@rad.unimaas.nl

    2008-01-15

    Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 {+-} 3.1 vs. 3.0 T: 50.7 {+-} 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 {+-} 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 {+-} 0.3), and lowest for non-enhanced 3.0 T (1.7 {+-} 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T.

  9. Cardiac cine MRI: Comparison of 1.5 T, non-enhanced 3.0 T and blood pool enhanced 3.0 T imaging

    Introduction: Cardiac cine imaging using balanced steady state free precession sequences (bSSFP) suffers from artefacts at 3.0 T. We compared bSSFP cardiac cine imaging at 1.5 T with gradient echo imaging at 3.0 T with and without a blood pool contrast agent. Materials and methods: Eleven patients referred for cardiac cine imaging underwent imaging at 1.5 T and 3.0 T. At 3.0 T images were acquired before and after administration of 0.03 mmol/kg gadofosveset. Blood pool signal-to-noise ratio (SNR), temporal variations in SNR, ejection fraction and myocardial mass were compared. Subjective image quality was scored on a four-point scale. Results: Blood pool SNR increased with more than 75% at 3.0 T compared to 1.5 T (p < 0.001); after contrast administration at 3.0 T SNR increased with 139% (p < 0.001). However, variations in blood pool SNR at 3.0 T were nearly three times as high versus those at 1.5 T in the absence of contrast medium (p < 0.001); after contrast administration this was reduced to approximately a factor 1.4 (p = 0.21). Saturation artefacts led to significant overestimation of ejection fraction in the absence of contrast administration (1.5 T: 44.7 ± 3.1 vs. 3.0 T: 50.7 ± 4.2 [p = 0.04] vs. 3.0 T post contrast: 43.4 ± 2.9 [p = 0.55]). Subjective image quality was highest for 1.5 T (2.8 ± 0.3), and lowest for non-enhanced 3.0 T (1.7 ± 0.6; p = 0.006). Conclusions: GRE cardiac cine imaging at 3.0 T after injection of the blood pool agent gadofosveset leads to improved objective and subjective cardiac cine image quality at 3.0 T and to the same conclusions regarding cardiac ejection fraction compared to bSSFP imaging at 1.5 T

  10. Performance measurements of a pilot superconducting solenoid model core for a wind tunnel magnetic suspension and balance system

    Goodyer, M. J.; Britcher, C. P.

    1983-01-01

    The results of experimental demonstrations of a superconducting solenoid model core in the Southampton University Magnetic Suspension and Balance System are detailed. Technology and techniques relevant to large-scale wind tunnel MSBSs comprise the long term goals. The magnetic moment of solenoids, difficulties peculiar to superconducting solenoid cores, lift force and pitching moment, dynamic lift calibration, and helium boil-off measurements are discussed.

  11. Commissioning report of the MuCool 5 Tesla solenoid coupled with helium refrigerator

    Geynisman, Michael; /Fermilab

    2010-05-01

    MuCool 5T solenoid was successfully cooled down and operated coupled with MTA 'Brown' refrigerator. The system performed as designed with substantial performance margin. All process alarms and interlocks, as well as ODH and fire alarms, were active and performed as designed. The cooldown of the refrigerator started from warm conditions and took 44 hours to accumulate liquid helium level and solenoid temperature below 5K. Average liquid nitrogen consumption for the refrigerator precool and solenoid shield was measured as 20 gal/hr (including boil-off). Helium losses were small (below 30 scfh). The system was stable and with sufficient margin of performance and ran stably without wet expansion engine. Quench response demonstrated proper operation of the relieving devices and pointed to necessity of improving tightness of the relieving manifolds. Boil-off test demonstrated average heat load of 3 Watts for the unpowered solenoid. The solenoid can stay up to 48 hours cold and minimally filled if the nitrogen shield is maintained. A list of improvements includes commencing into operations the second helium compressor and completion of improvements and tune-ups for system efficiency.

  12. 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.

  13. 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...

  14. Cardiac MR tagging: optimization of sequence parameters and comparison at 1.5 T and 3.0 T in a volunteer study

    Purpose: The aim of this study was the optimization of a gradient echo (GRE) MR tagging sequence at 3.0 T in comparison to 1.5 T in order to obtain the best image contrast between the myocardium, tag lines and blood signal. Theoretically expected improvements of signal-to-noise (SNR) and contrast-to-noise ratios (CNR) were also calculated. Materials and methods: 14 healthy volunteers (8 male, 6 female; mean age 43.4±10.3 years) were scanned using a 3.0 T as well as a 1.5 T whole-body system. A GRE flash-2 D tagging sequence was evaluated (midventricular short axis view) by varying the flip angle (8-16 ), slice thickness (4-8 mm; fixed flip angle 1.5/3.0 T: 12 /8 , tag size 8 mm) and tag size (4-8 mm, fixed flip angle 1.5/3.0 T: 12 /8 , slice thickness 6 mm). The field of view, acquisition time and temporal resolution (45 ms) were kept constant. Qualitative and quantitative image analysis was performed by calculating the SNR, CNRtag as well as the relative contrast between the myocardium and tag lines (RCMT). Results: Based on individual comparison, the best imaging protocol was found at a slice thickness of 6 mm, tag size of 8 mm, optimized flip angle of 8 (3.0 T) and 12 (1.5 T), respectively. Compared to 1.5 T, a significantly higher overall image score was determined (mean±sd; 3.2±0.2 vs 2.7±0.4) and a strong correlation between the CNRtag and RCMT for flip angle α and the slice thickness was found. A higher field strength resulted in an 80% increase in the CNRtag compared to 1.5 T (mean 10.7/6.1). Furthermore, the SNR was improved by 35% (mean 20.6/15.3) and the RCMT by 35% (mean 0.47/0.35). Conclusion: Myocardial tagging at 3.0 T has shown superior image quality in comparison to 1.5 T due to a higher baseline SNR and an improved CNR as well as RCMT. The suppressed fading of the tags enables the accessibility to the diastolic phase of the cardiac cycle. (orig.)

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

    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

  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. The SISSI project: an intense secondary ion source using superconducting solenoid lenses

    Secondary beams are routinely produced at GANIL for experiments from a target placed in the high energy beam line of the accelerator. In order to make a better use of the higher beam intensities soon available at GANIL, a proposal called SISSI was presented in 1989. This project is now funded. It consists of a set of two superconducting solenoid lenses of very short focal length (.6m). The first solenoid is used to sharply focus the incoming beam on a fast moving target. The second increases the angular acceptance of the beam line downstream the target for charged reaction products. Calculations show that from .4mm diameter beam spot on the target, an acceptance angle of up to 80 mrad will be reached without significant emittance growth due to aberration effects. Technical aspects of that project are then presented concerning both the solenoids and the cryogenic devices as well as the solid target

  18. Analysis of eddy current distributions in the CMS magnet yoke during the solenoid discharge

    Klioukhine, Vyacheslav I; Curé, Benoî; Gaddi, Andrea; Gerwig, Hubert; Grillet, Jean Paul; Hervé, A; Loveless, Richard; Smith, Richard P; 10.1109/TNS.2005.850932

    2005-01-01

    Flux loops have been installed on selected segments of the magnetic flux return yoke of the 4 T superconducting coil of the Compact Muon Solenoid (CMS) detector under construction at CERN. Voltages induced in the loops during discharge of the solenoid will be sampled online during the entire discharge and integrated offline to provide a measurement of the initial magnetic flux density in steel at the maximum field to an accuracy of a few percent. Although the discharge of the solenoid is rather slow (190 s time constant), the influence of eddy currents induced in the yoke elements should be estimated. The calculation of eddy currents is performed with Vector Fields' program ELEKTRA. The results of the calculations are reported.

  19. Analysis of Eddy Current Distributions in the CMS Magnet Yoke During the Solenoid Discharge

    Klyukhin, V I; Curé, B; Gaddi, A; Gerwig, H; Grillet, J P; Hervé, A; Loveless, R; Smith, R P

    2011-01-01

    Flux loops have been installed on selected segments of the magnetic flux return yoke of the 4 T superconducting coil of the Compact Muon Solenoid (CMS) detector under construction at CERN. Voltages induced in the loops during discharge of the solenoid will be sampled online during the entire discharge and integrated offline to provide a measurement of the initial magnetic flux density in steel at the maximum field to an accuracy of a few percent. Although the discharge of the solenoid is rather slow (190 s time constant), the influence of eddy currents induced in the yoke elements should be estimated. The calculation of eddy currents is performed with Vector Fields' program ELEKTRA. The results of the calculations are reported.

  20. The Density Probability Distribution in Compressible Isothermal Turbulence: Solenoidal vs Compressive Forcing

    Federrath, Christoph; Schmidt, Wolfram

    2008-01-01

    The probability density function (PDF) of the gas density in turbulent supersonic flows is investigated with high-resolution numerical simulations. In a systematic study, we compare the density statistics of compressible turbulence driven by the usually adopted solenoidal forcing (divergence-free) and by compressive forcing (curl-free). Our results are in agreement with studies using solenoidal forcing. However, compressive forcing yields a significantly broader density distribution with standard deviation ~3 times larger at the same rms Mach number. The standard deviation-Mach number relation used in analytical models of star formation is reviewed and a modification of the existing expression is proposed, which takes into account the ratio of solenoidal and compressive modes of the turbulence forcing.

  1. Design and performance of fast ramping and modulation coil geometries in superconducting solenoids

    The design and manufacturer of fast ramping and modulation coil geometries using wire wound filamentary Nb/sub 3/Sn and NbTi standard conductors is discussed. Construction and performance details are presented for three different solenoid designs. First, a NbTi 120mm bore two section magnet with an inner section capable of generating an additional 1 Tesla field in 10 seconds with the outer section energized to 7 Tesla. Secondly, a 2 Tesla 45kmm bore NMR solenoid which can be energized to full field in 1.1 seconds. Thirdly, a Nb/sub 3/Sn modulation coil which can produce a modulation field of 50 milliTesla at frequencies up to 1 kHz within the bore of a 12 Tesla solenoid

  2. A feasibility study of a linear laser heated solenoid fusion reactor. Final report

    This report examines the feasibility of a laser heated solenoid as a fusion or fusion-fission reactor system. The objective of this study, was an assessment of the laser heated solenoid reactor concept in terms of its plasma physics, engineering design, and commercial feasibility. Within the study many pertinent reactor aspects were treated including: physics of the laser-plasma interaction; thermonuclear behavior of a slender plasma column; end-losses under reactor conditions; design of a modular first wall, a hybrid (both superconducting and normal) magnet, a large CO2 laser system; reactor blanket; electrical storage elements; neutronics; radiation damage, and tritium processing. Self-consistent reactor configurations were developed for both pure fusion and fusion-fission designs, with the latter designed both to produce power and/or fissile fuels for conventional fission reactors. Appendix A is a bibliography with commentary of theoretical and experimental studies that have been directed at the laser heated solenoid

  3. Novel MEMS-based fabrication technology of micro solenoid-type inductor

    Solenoid configuration of micro inductor, which has advantages of high quality factor and low loss, is needed in micro energy and power electronics applications but it is difficult to prepare using conventional microfabrication processes. In this work, we present a new microelectromechanical systems-based technology of micro solenoid-type inductor by a newly developed cylindrical projection photolithography method. Direct electroplating process of copper film on coil patterns was also successfully developed for achieving thick windings so that thick photoresist-based electroplating molds are not needed. Micro solenoid-type inductor prototypes of the winding pitch of about 40 µm, the winding number of 20 and 50, and the winding thickness of about 14 µm, were successfully fabricated on a 1 mm diameter glass capillary. The prepared 20-turn and 50-turn micro inductors were of inductance of 69 and 205 nH at 30 MHz, respectively. (paper)

  4. Coherent states of non-relativistic electron in the magnetic-solenoid field

    In the present work we construct coherent states in the magnetic-solenoid field, which is a superposition of the Aharonov-Bohm field and a collinear uniform magnetic field. In the problem under consideration there are two kinds of coherent states, those which correspond to classical trajectories which embrace the solenoid and those which do not. The constructed coherent states reproduce exactly classical trajectories, maintain their form under the time evolution and form a complete set of functions, which can be useful in semiclassical calculations. In the absence of the solenoid field these states are reduced to the well known in the case of uniform magnetic field Malkin-Man'ko coherent states.

  5. Electrons in a positive-ion beam with solenoid or quadrupole magnetic transport

    The High Current Experiment (HCX) is used to study beam transport and accumulation of electrons in quadrupole magnets and the Neutralized Drift-Compression Experiment (NDCX) to study beam transport through and accumulation of electrons in magnetic solenoids. We find that both clearing and suppressor electrodes perform as intended, enabling electron cloud densities to be minimized. Then, the measured beam envelopes in both quadrupoles and solenoids agree with simulations, indicating that theoretical beam current transport limits are reliable, in the absence of electrons. At the other extreme, reversing electrode biases with the solenoid transport effectively traps electrons; or, in quadrupole magnets, grounding the suppressor electrode allows electron emission from the end wall to flood the beam, in both cases producing significant degradation in the beam

  6. The superconducting solenoid magnet system for the GEM detector at the SSC

    The design of the magnet for the GEM detector at the SSC is described. It is an 18m inner diameter, 30m long superconducting solenoid, with a magnetic field of 0.8 T. The basic solenoidal field is shaped by large ferromagnetic cones, to improve detector performance in the ends of the solenoid. Because of the system's large size and mass, field-fabrication on-site at the SSC is required. The challenges in this process, together with the large stored energy of the system, 2.5 GJ, have lead to novel design choices in several areas, including the conductor. The design of the conductor, cold mass, vacuum vessel, cold mass supports, thermal shields, forward field shapers, and auxiliary systems are described

  7. Ex vivo evaluation of ferromagnetism for metallic ocular and middle-ear prostheses exposed to a 1.5-T MR imager

    This paper determines ferromagnetism by measuring deflection angles for nine different metallic ocular and middle-ear biomedical implants exposed to a 1.5-T MR imager. Deflection angles were determined at the bore of a 1.5-t MR imager for two ocular (Fatio eyelid wire 0.008, Fatio eyelid wire 0.01) and seven middle-ear (House tantalum single loop, House tantalum double loop, IRP, Schuknecht tef-wire piston, Austin tytan piston, McGee piston, Robinson stapes prosthesis) biomedical implants. A previously described, standardized methodology was used to measure deflection angles. Deflection angles for the biomedical implants were 90 degrees for the first ocular implant, over 90 degrees for the second, and 0 degrees (no deflection measured) for the seven middle-ear implants

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

    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

  9. 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.

  10. 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.

  11. 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.

  12. Wide flat-topped fow forizontal component field solenoid coil design

    This paper describes the application of non-uniform coil winding techniques and homogenizer rings technique in the design of solenoid coil. The two techniques can be used to reduce the magnetic field space fluctuations and shield horizontal magnetic field component, respectively. The solenoid coil design results for 12 MeV LIA in CAEP show that by using the two techniques the magnetic field fluctuations in the accelerator gap can be reduced by about 70% and the horizontal field component can be reduce to about 3.5%. (authors)

  13. Design of wide flat-topped low transverse field solenoid magnet

    A wide flat-topped low transverse error field solenoid magnet design for linear induction accelerator is presented. The design features non-uniform winding to reduce field fluctuation due to the magnets' gap, and homogenizer rings within the solenoid to greatly reduce the effects of winding errors. Numerical modeling of several designs for 12 MeV linear induction accelerator (LIA) in China Academy of Engineering Physics has demonstrated that by using these two techniques the magnetic field fluctuations in the accelerator gap can be reduced by 70% and the transverse error field can be reduced by 96.5%. (authors)

  14. Fabrication of a solenoid-type inductor with Fe-based soft magnetic core

    A solenoid-type inductor was fabricated by MEMS (Microelectromechanical systems) technique. The fabrication process uses UV-LIGA, dry etching, fine polishing, and electroplating technique to achieve high performance of the solenoid-type inductor. Fe-based soft magnetic thin film was sputtered as the magnetic core, and polyimide was used as the insulation materials. The inductor was in size of 4x4 mm with coil width of 20 μm and space of 35 μm. The inductance is 1.61 μH at a frequency of 5 MHz with the maximum quality factor of 1.42

  15. 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.

  16. 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.

  17. 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.

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

    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.

  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. PMID:22380298

  20. 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.

  1. Design and Development of a Miniaturized Double Latching Solenoid Valve for the Sample Analysis at Mars Instrument Suite

    Smith, James T.

    2008-01-01

    The development of the in-house Miniaturized Double Latching Solenoid Valve, or Microvalve, for the Gas Processing System (GPS) of the Sample Analysis at Mars (SAM) instrument suite is described. The Microvalve is a double latching solenoid valve that actuates a pintle shaft axially to hermetically seal an orifice. The key requirements and the design innovations implemented to meet them are described.

  2. 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

  3. Design of the probe for low-field pulsed NMR instrument

    The probe is the most sensitive and important component in the low-field pulsed NMR instrument. Compared with other kinds of probes used in NMR instruments, the probe made with solenoid can get high Q(quality factor) value and uniform magnetic field. Based on the analysis of the probe's circuit, a theoretic formula is obtained, according to which, one high-quality probe is designed with solenoid. The selection of the high-quality components and the probe's testing method are also introduced in detail. (authors)

  4. Mechanical properties of the ITER central solenoid model coil insulation under static and dynamic load after reactor irradiation

    The candidate insulation system for the central solenoid (CS) model coil of the International Thermonuclear Experimental Reactor (ITER) is CTD-112P, an epoxy with a two-dimensionally woven S-glass-fiber reinforcement. Because of the pulsed operation of ITER, both the static and the fatigue behavior of the material have to be assessed under the actual operating conditions, including the appropriate radiation environment at the magnet location. To obtain information on the radiation-induced material degradation, the material was irradiated at ambient and low temperatures to neutron fluences of 5 x 1022 m-2 (E > 0.1 MeV). After measurements of swelling and weight loss, all experiments were carried out at 77 K. Half of the 5 K irradiated samples were subjected to a warm-up cycle to room temperature before testing. Tensile and short-beam-shear tests characterize the material in tension and interlaminar shear. Stress-lifetime diagrams of tensile and double-lap-shear specimens were assessed under tension-tension fatigue load up to 106 cycles

  5. Pulse on Pulse

    Schmidt, Ulrik; Carlson, Merete

    2012-01-01

    of the visitor’s beating heart to the blink of a fragile light bulb, thereby transforming each light bulb into a register of individual life. But at the same time the blinking light bulbs together produce a chaotically flickering light environment composed by various layers of repetitive rhythms, a vibrant...... 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...... (flickering light bulbs; polyrhythmic layers). Taking our point of departure in a discussion of Gilles Deleuze’s concepts of modulation and signaletic material in relation to electronic media, we examine how the complex orchestration of pulsation between signification and material modulation produces...

  6. 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. PMID:26794489

  7. Toroidal solenoids in the electromagnetic field and Aharonov-Casher effect

    The current toroidal configurations are found which generate gauge nonequivalent vector potentials and correspond to the same quantum scattering of charged particles. The equations for the motion of toroidal moment in the magnetic field are obtained. It is proved the existence of Aharonov-Casher effect for the toroidal solenoids. The relating experiments are proposed. 19 refs.; 7 figs

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

    L. Larchenkov

    2014-09-01

    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.

  9. Worcester 1 Inch Solenoid-Actuated Gas-Operated VPS System Ball Valve

    1 inch Gas-operated full-port ball valve incorporates a solenoid and limit switches as integral parts of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS

  10. Development of large high current density superconducting solenoid magnets for use in high energy physics experiments

    The development of a unique type of large superconducting solenoid magnet, characterized by very high current density windings and a two-phase helium tubular cooling system is described. The development of the magnet's conceptual design and the construction of two test solenoids are described. The successful test of the superconducting coil and its tubular cooling refrigeration system is presented. The safety, environmental and economic impacts of the test program on future developments in high energy physics are shown. Large solid angle particle detectors for colliding beam physics will analyze both charged and neutral particles. In many cases, these detectors will require neutral particles, such as gamma rays, to pass through the magnet coil with minimum interaction. The magnet coils must be as thin as possible. The use of superconducting windings allows one to minimize radiation thickness, while at the same time maximizing charged particle momentum resolution and saving substantial quantities of electrical energy. The results of the experimental measurements show that large high current density solenoid magnets can be made to operate at high stored energies. The superconducting magnet development described has a positive safety and environmental impact. The use of large high current density thin superconducting solenoids has been proposed in two high energy physics experiments to be conducted at the Stanford Linear Accelerator Center and Cornell University as a result of the successful experiments described

  11. Worcester 1 Inch Solenoid-Actuated Gas-Operated VPS System Ball Valve

    1 inch Gas-operated full-pod ball valve incorporates a solenoid and limit switches as integral park of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS

  12. Worcester 1 Inch Solenoid Actuated Gas Operated VPS System Ball Valve

    MISKA, C.R.

    2000-11-13

    1 inch Gas-operated full-pod ball valve incorporates a solenoid and limit switches as integral park of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS.

  13. 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).

  14. Development of solenoids and combined function steering magnets for LEBT of proton linac

    Focusing solenoids and large aperture (184 mm) combined function steering magnets are required for Low Energy Beam Transport (LEBT) line for transporting the negative hydrogen ion beam from the Ion source to Radio Frequency Quadrupole (RFQ) of H-injector Linac at RRCAT. The integral field strength (≀f(Bz)2) of water cooled solenoids is (3.5 kG)2 x 30 cm and the integrated field strength (Bx.L and By.L) of steering magnets is 1500 G-cm. The technical challenges involved in development of these magnets are to satisfy the field quality requirements (spherical aberration coefficient, C1 < 30/m2 for solenoids and field uniformity < 1% for steering magnets) and install them with support systems in the limited space available in between the ion source and RFQ of the high Energy proton Linac. The magnets were designed using POISSON 2D and OPERA 3D codes. Two water cooled solenoids and two combined function steering magnets with support systems have been developed. The details of magnet development with their support systems and results of magnetic field measurement will be discussed in this paper. (author)

  15. Pulsed magnetic field for PHERMEX-injected circular accelerator

    The PHERMEX accelerator is a standing wave, 50 MHz rf linear accelerator. The rf fields in three cavities are pulsed for a period of 3 ms. The experiments described are directed toward studying injection and trapping of electron rings at modes field strengths (approximately 1 T). A single 200 ns beam macropulse is to be injected transverse to a solenoidal field, which is tilted at a small angle relative to the beam normal so that a beam micropulse does not return and strike the injection point. The pulsed field coils and vacuum chamber are reported under construction, and the capacitor bank being tested

  16. Neutron emission from the ''UTRO'' pulsed thermonuclear device

    Technique of investigations into neutron radiation in experiments on low-compression heating of dense plasma in the UTRO linear theta-pinch with a strong (B7 neutr/pulse. Dependence of neutron pulse duration on initial deuterium pressure in a discharge chamber in the range of 0.1-1 torr is given as well. It is concluded that there is a possibility for increasing plasma neutron radiation power of the fast linear theta-pinch when increasing magnetic field in the solenoid and initial pressure in the discharge chamber

  17. Development of Aluminum Stabilized Superconducting Cables for the Mu2e Detector Solenoid

    Lombardo, Vito [Fermilab; Buehler, M. [Fermilab; Lamm, M. [Fermilab; Page, T. [Fermialb; Curreli, S. [INFN, Genoa; Fabbricatore, P. [INFN, Genoa; Musenich, R. [INFN, Genoa

    2015-10-16

    The Mu2e experiment at Fermilab is designed to measure the rare process of direct muon-to-electron conversion in the field of a nucleus. The experiment comprises a system of three superconducting solenoids, which focus secondary muons from the production target and transport them to an aluminum stopping target, while minimizing the associated background. The Detector Solenoid (DS) is the last magnet in the transport line and its main functions are to provide a graded field in the region of the stopping target as well as a precision magnetic field in a volume large enough to house the tracker downstream of the stopping target. The Detector Solenoid coils are designed to be wound using NbTi Rutherford cables conformed in high purity aluminum for stabilization and then cold-worked for strength. Two types of Al-stabilized conductor are required to build the DS coils, one for the gradient section and one for the spectrometer section of the solenoid. The dimensions are optimized to generate the required field profile when the same current is transported in both conductors. The conductors contain NbTi Rutherford cables with 12 (DS1) and 8 (DS2) strands respectively and are manufactured by two different vendors. This paper describes the results of the manufacturing of production lengths of the Al-stabilized cables needed to build the Mu2e Detector Solenoid as well as the testing campaigns and main results. The main cable properties and results of electrical and mechanical tests are summarized and discussed for each stage of the cable development process. Results are compared to design values to show how the production cables satisfy all the design criteria starting from the NbTi wires to the Al-stabilized cables.

  18. Analysis of power deposition and temperature rise due to presence of an implant inside a 1.5 t MRI RF coil.

    Kozlov, M; Schaefers, G

    2015-08-01

    We numerically investigated power deposition and temperature rise generated due to the presence of a titanium rod placed in a phantom, located inside a 1.5 T coil. The induced power deposition and temperature rise normalized to incident tangential electric field was found to be dependent on distance to the phantom wall. The different dependence of the integral of power deposition over a box surrounded the rod and the temperature rise on American Society for Testing and Materials (ASTM) phantom medium electrical conductivity was observed. The consequences of numerical domain simplification have been analyzed. PMID:26737609

  19. MRI of knee joint: first results of a comparison of a 0.2 T dedicated system with a 1.5 T high field strength magnet

    Diagnostic accuracy and image quality of a specialised system for MR examinations of peripheral joints were evaluated. 20 patients with acute or chronic injuries of the knee were examined using a low-field MR system (0.2 T). For comparison, all patients were also studied with a 1.5 T high field strength magnet and all diagnoses were correlated with arthroscopic findings. We found compatible diagnostic accuracies (cruciate ligaments 90%, menisci 75-90%) and good image quality ratings for the low field system ('good' and 'excellent' image quality in 83% of cases). (orig./MR)

  20. The Dimensions and Number of Turns for the Spectrometer Solenoids As-Built compared to the Original Magnet Design

    The two tracker solenoids for MICE [1]-[3] as-built are different from the original design proposed by Wang NMR [4]. The Wang NMR design is in turn different from the magnet design proposed in the original MICE tracker magnet specification [5]. The two tracker solenoids where fabricated with niobium titanium conductor supplied to LBNL by Luvata under a specification written by LBNL [6]. This report compares the as-built tracker solenoids to the original Wang NMR design [4]. The as-built solenoid coils are thicker by 5 to 8 percent than called for the original design. This means that the current center is moved outward from 0.2 to 0.5 percent. In both tracker magnets, the thickness of end coil 2 was increased by 2-layers over the original design [5]. Thus, the current center for end coil 2 was moved outward by 0.7 percent. The number of turns per layer was underestimated in the original design from 2 to 4 percent. As a result, the current in each of the five tracker solenoid coils must be increased. In turn, the two as built tracker solenoids are compared to each other. In the ways that matter, the two tracker solenoids are nearly identical to each other. The largest difference between the two magnets that matters is a 0.05 percent change in the current in the center coil of the three coil set that forms the spectrometer solenoid. Since this is the largest variation that matters, it can be concluded that coils M1, coils M2, and the spectrometer solenoid can be connected in series without affecting the beam dynamics of MICE. This includes the two tuned end coils as well. The position of the coils within the cryostats vacuum vessel appears to be acceptable

  1. 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.

  2. 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.

  3. The design and fabrication of the PDX [Poloidal Divertor Experiment] poloidal field solenoid utilizing fiberglass reinforced epoxy

    This paper discusses the basic design of the Poloidal Field Solenoid Coil. It will be mainly concerned with the more unique features of the Solenoid such as the copper coil windings and the design of the epoxy-glass structural support mandrels. The center solenoid coil of the PDX machine consists of five different coil systems. Three concentric fiberglass reinforced epoxy cylinder fabricated in-house will act as mandrels to support and to house the coils that will result as an integral unit. 1 ref., 4 figs., 1 tab

  4. Wave equations for pulse propagation

    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

  5. Identification, molecular and functional characterization of calmodulin gene of Phytomonas serpens 15T that shares high similarity with its pathogenic counterparts Trypanosoma cruzi.

    de Souza, Tatiana de Arruda Campos Brasil; Graça-de Souza, Viviane Krominski; Lancheros, César Armando Contreras; Monteiro-Góes, Viviane; Krieger, Marco Aurélio; Goldenberg, Samuel; Yamauchi, Lucy Megumi; Yamada-Ogatta, Sueli Fumie

    2011-03-01

    In trypanosomatids, Ca²+-binding proteins can affect parasite growth, differentiation and invasion. Due to their importance for parasite maintenance, they become an attractive target for drug discovery and design. Phytomonas serpens 15T is a non-human pathogenic trypanosomatid that expresses important protein homologs of human pathogenic trypanosomatids. In this study, the coding sequence of calmodulin, a Ca²+-binding protein, of P. serpens 15T was cloned and characterized. The encoded polypeptide (CaMP) displayed high amino acid identity to homolog protein of Trypanosoma cruzi and four helix-loop-helix motifs were found. CaMP sequence analysis showed 20 amino acid substitutions compared to its mammalian counterparts. This gene is located on a chromosomal band with estimated size of 1,300 kb and two transcripts were detected by Northern blot analysis. A polyclonal antiserum raised against the recombinant protein recognized a polypeptide with an estimated size of 17 kDa in log-phase promastigote extracts. The recombinant CaMP retains its Ca²+-binding capacity. PMID:21431874

  6. 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.

  7. Posterior fossa dural arteriovenous fistulas: diagnosis and follow-up with time-resolved imaging of contrast kinetics (TRICKS) at 1.5T

    Pekkola, Johanna; Kangasniemi, Marko (Helsinki Medical Imaging Center, Helsinki Univ. Central Hospital, Helsinki (Finland)), email: johanna.pekkola@hus.fi

    2011-05-15

    Background Time-of-flight MR angiography (TOF MRA) is currently the most widely used non-invasive imaging tool to diagnose dural arteriovenous fistula (DAVF). It is, however, not as sensitive as invasive digital subtraction angiography (DSA) for detecting the arteriovenous shunting inherent in DAVF. Dynamic contrast-enhanced MR angiography allows separation of arterial and venous phases of contrast passage though the brain and can thus demonstrate early venous filling through the arteriovenous shunt. Purpose To compare the diagnostic value of TOF MRA and a commercially available dynamic contrast-enhanced MR angiography sequence (TRICKS) at 1.5T in detecting posterior fossa DAVF. Material and Methods We retrospectively collected image data for 19 patients who underwent TOF MRA, TRICKS, and DSA either for primary diagnosis or for follow-up of posterior fossa DAVF and assessed the performance of TOF MRA and TRICKS in demonstrating the arteriovenous shunt, with DSA as the reference standard. Results TRICKS detected early arterial filling at 94.4% sensitivity and 83.3% specificity. TOF MRA detected high flow-related signal within venous structures at 64.7% sensitivity and 80% specificity. Conclusion The commercially available dynamic MR angiography sequence TRICKS with fully automatic vendor postprocessing at 1.5T is more sensitive than TOF MRA in detecting the arteriovenous shunt in posterior fossa DAVF

  8. MR-guided radiofrequency ablation using a wide-bore 1.5-T MR system: clinical results of 213 treated liver lesions

    To evaluate the technical effectiveness, technical success and patient safety of MR-guided radiofrequency (RF) ablation of liver malignancies using a wide-bore 1.5-T MR system. In 110 patients, 56 primary liver lesions and 157 liver metastases were treated in 157 sessions using percutaneous RF ablation. Mean lesion diameter was 20 mm (range 4-54 mm). All planning, procedural and post-interventional control MR investigations were carried out using a wide-bore 1.5-T MR system. Technical success was assessed by a contrast-enhanced MR liver examination immediately after the intervention. Technique effectiveness was assessed by dynamic hepatic MR study 1 month post ablation; mean follow-up period was 24.2 months (range 5-44). Technical success and technique effectiveness were achieved in 210/213 lesions (98.6 %). In 18/210 lesions (8.6 %), local tumour progression occurred 4-28 months after therapy. Seven of these 18 lesions were treated in a second session achieving complete ablation, 6 other lesions were referred to surgery. Overall RF effectiveness rate was 199/213 (93.4 %); overall therapy success (including surgery) was 205/213 (96.2 %). Two major complications (1.3 %) (bleeding and infected biloma) and 14 (8.9 %) minor complications occurred subsequent to 157 interventions. Wide-bore MR-guided RF ablation is a safe and effective treatment option for liver lesions. (orig.)

  9. Research design and improvement of high temperature high pressure solenoid valve

    A process for development of the pilot type high temperature high pressure solenoid valve used in a PWR power plant is described. The whole development process might be divided into two phases: research design and improvement. In the former phase the questions had chiefly been approached in the following several aspects: the principle construction design, the determination of values for the constructionally key elements, the valve seal design and the solenoid actuator design, and made such valve's successful design in the main. In the latter phase an improvement had been made upon such valve against the problems during the testing use of the valve for a period of time, i.e. the unsatisfactory leak tightness, and achieved satisfactory results. The consummate success in this development not only has met the needs of the engineering project, but also made us obtain a valuable experience useful to design the similar valves

  10. Confinement physics for thermal, neutral, high-charge-state plasmas in nested-well solenoidal traps.

    Dolliver, D D; Ordonez, C A

    1999-06-01

    A theoretical study is presented which indicates that it is possible to confine a neutral plasma using static electric and solenoidal magnetic fields. The plasma consists of equal temperature electrons and highly stripped ions. The solenoidal magnetic field provides radial confinement, while the electric field, which produces an axial nested-well potential profile, provides axial confinement. A self-consistent, multidimensional numerical solution for the electric potential is obtained, and a fully kinetic theoretical treatment on axial transport is used to determine an axial confinement time scale. The effect on confinement of the presence of a radial electric field is explored with the use of ion trajectory calculations. A thermal, neutral, high-charge-state plasma confined in a nested-well trap opens new possibilities for fundamental studies on plasma recombination and cross-field transport processes under highly controlled conditions. PMID:11969700

  11. 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.

  12. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Wibowo, Zakaria, Lambang, Lullus; Triyono, Muhayat, Nurul

    2016-03-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  13. On the solenoidal heat-flux in quasi-ballistic thermal conduction

    Ramu, Ashok T.; Bowers, John E.

    2015-09-01

    The Boltzmann transport equation for phonons is recast directly in terms of the heat-flux by means of iteration followed by truncation at the second order in the spherical harmonic expansion of the distribution function. This procedure displays the heat-flux in an explicitly coordinate-invariant form, and leads to a natural decomposition into two components, namely, the solenoidal component in addition to the usual irrotational component. The solenoidal heat-flux is explicitly shown to arise by applying the heat-flux equation to a right-circular cylinder. These findings are important in the context of phonon resonators that utilize the strong quasi-ballistic thermal transport reported recently in silicon membranes at room temperature.

  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. 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. [Fermi National Accelerator Laboratory, P. O. Box 500, Batavia, IL 60510 (United States)

    2014-01-29

    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.

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

    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

  17. Worcester 1 Inch Solenoid-Actuated Gas Operated SCHe System Valves

    1 inch gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated

  18. A Statistical Study of Beam Centroid Oscillations in a Solenoid Transport Channel

    Lund, S; Wootton, C; Coleman, J; Lidia, S; Seidl, P

    2009-05-07

    A recent theory of transverse centroid oscillations in solenoidally focused beam transport lattices presented in Ref. [1] is applied to statistically analyze properties of the centroid orbit in the Neutralized Drift Compression Experiment (NDCX) at the Lawrence Berkeley National Laboratory. Contributions to the amplitude of the centroid oscillations from mechanical misalignments and initial centroid errors exiting the injector are analyzed. Measured values of the centroid appear consistent with expected alignment tolerances. Correction of these errors is discussed.

  19. A comparative study of PPM and solenoid focusing in multibeam electron gun

    This paper represents the comparison of periodic permanent magnet (PPM) and solenoid focusing for dual anode multi-beam electron gun using OPERA3D code. The electron gun has been operated at 6 kV having 75 mA beam current with 0.45 mm beam waist radius. The design has an additional feature of cathode protection from ion bombardment with the application of extra ion barrier anode.

  20. Engineering design solutions of flux swing with structural requirements for ohmic heating solenoids

    Here a more detailed publication is summarized which presents analytical methods with solutions that describe the structural behavior of ohmic heating solenoids to achieve a better understanding of the relationships between the functional variables that can provide the basis for recommended design improvements. The solutions relate the requirements imposed by structural integrity to the need for producing sufficient flux swing to initiate a plasma current in the tokamak fusion machine. A method is provided to perform a detailed structural analysis of every conducting turn in the radial build of the solenoid, and computer programmed listings for the closed form solutions are made available as part of the reference document. Distinction is made in deriving separate models for the regions of the solenoid where turn-to-turn radial contact is maintained with radial compression or with a bond in the presence of radial tension, and also where there is turn-to-turn radial separation due to the absence or the loss of bonding in the presence of would be radial tension. The derivations follow the theory of elasticity for a body possessing cylindrical anisotropy where the material properties are different in the radial and tangential directions. The formulations are made practical by presenting the methods for reducing stress and for relocating the relative position for potential turn-to-turn radial delamination by permitting an arbitrary traction at the outer radial surface of the solenoid in the form of pressure or displacement such as may be applied by a containment or a shrink fit structural cylinder

  1. Initial plasma start-up using partial solenoid coils in Versatile Experiment Spherical Torus (VEST)

    Highlights: ► Initial plasma start-up experiments using unique partial solenoid coils are conducted in VEST. ► Ohmic discharges with ECH pre-ionization have been performed with pre-programed start-up scenario. ► A plasma current of around 0.4 kA has been achieved by using partial solenoid coils at Bt = 0.1 T. ► Modified start-up scenario with upgraded power supplies will be pursued for higher plasma currents. -- Abstract: Initial plasma start-up experiments based on ohmic discharge using partial solenoid coils located at both vertical ends of a center stack have been carried out in Versatile Experiment Spherical Torus (VEST) at Seoul National University. Ohmic discharges with the help of microwave pre-ionization have been performed according to the pre-programed start-up scenario which was experimentally verified by a series of vacuum field measurements using an internal magnetic probe array. A plasma current of around 0.4 kA has been achieved by ohmic discharge using partial solenoid coils, under the toroidal magnetic field of 0.1 T. The vacuum field calculation and fast camera image have revealed that the small plasma current even with significant amount of loop voltage up to 9.7 V is attributed to the imbalance of poloidal field for equilibrium. Modification of the start-up scenario and upgrade of power supplies are proposed to be carried out in order to achieve higher plasma current in the future experiments

  2. Worcester 1 Inch Solenoid-Actuated Gas Operated SCHe System Valves

    1 inch Gas-operated full-port ball valves incorporate a solenoid and limit switches as integral parts of the actuator. These valves are normally open and fail safe to the open position (GOV-1*02 and 1*06 fail closed) to provide a flow path of helium gas to the MCO under helium purge and off-normal conditions when the MCO is isolated

  3. Fabrication of the three-dimensional solenoid type micro magnetic sensor

    There has been a large demand for the realization of on-chip fluxgate magnetic sensors, with exciting and sensing control IC circuits. Based on UV lithography and other MEMS technology, a new three dimensional solenoid type micro magnetic sensor has been designed and fabricated to measure the components of magnetic induction vector in outer space. The fabricated micro sensor was integrated in IC circuits of MEMS satellite

  4. Solenoid valves in the pressurizer systems of pressurized water reactors. Magnetventile im Druckhaltesystem von Druckwasserreaktoren

    Jocham, H. (Herion-Werke KG, Fellbach (Germany, F.R.))

    1990-07-01

    The safe functioning of the pressurizer system is a very important feature in the safety of the primary systems of nuclear power plants equipped with pressurized water reactors. The decisive units determining the reliability of the pressurizer are the solenoid actuated valves employed as spray systems for pressure control. These spray valves are components of the primary system and, in a way analogous to the reactor pressure vessel, must satisfy the most stringent safety and quality criteria. (orig.).

  5. 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).

  6. Photon Production From The Scattering of Axions Out of a Solenoidal Magnetic Field

    Guendelman, Eduardo I.; Shilon, Idan; Cantatore, Giovanni; Zioutas, Konstantin

    2009-01-01

    We calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a 2D delta-function, a cylindrical step function and a 2D Gaussian distribution, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the axion-photon conversion probability which could be expected in a reasonable experimental situation. The calculated conversion probabilities for QCD inspire...

  7. Effect of magnetic system errors on the transport processes in long solenoids

    The equilibrium of plasma and the transverse transport in the solenoidal cell of the axisymmetric open traps is investigated. The shape of magnetic surfaces in plasma with arbitrary large β ratio is found. The classification of possible regimes of nonclassical and resonant transport is given. The transport coefficients are evaluated and the magnetic field errors limitations providing guarantee that the transport is not greater then the classical one are pointed out

  8. 3D Whole-Heart Coronary MR Angiography at 1.5T in Healthy Volunteers: Comparison between Unenhanced SSFP and Gd-Enhanced FLASH Sequences

    To validate the optimal cardiac phase and appropriate acquisition window for three-dimensional (3D) whole-heart coronary magnetic resonance angiography (MRA) with a steady-state free precession (SSFP) sequence, and to compare image quality between SSFP and Gd-enhanced fast low-angle shot (FLASH) MR techniques at 1.5 Tesla (T). Thirty healthy volunteers (M:F 25:5; mean age, 35 years; range, 24-54 years) underwent a coronary MRA at 1.5T. 3D whole-heart coronary MRA with an SSFP was performed at three different times: 1) at end-systole with a narrow (120-msec) acquisition window (ESN), 2) mid-diastole with narrow acquisition (MDN); and 3) mid-diastole with wide (170-msec) acquisition (MDW). All volunteers underwent a contrast enhanced coronary MRA after undergoing an unenhanced 3D true fast imaging with steady-state precession (FISP) MRA three times. A contrast enhanced coronary MRA with FLASH was performed during MDN. Visibility of the coronary artery and image quality were evaluated for 11 segments, as suggested by the American Heart Association. Image quality was scored by a five-point scale (1 = not visible to 5 = excellent). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were evaluated at the proximal coronary arteries. The SSFP sequence rendered higher visibility coronary segments, higher image quality, as well as higher SNR and CNR than the Gd-enhanced FLASH technique at 1.5T (p < 0.05). The visibility of coronary segments, image quality, SNR and CNR in the ESN, MDN and MDW with SSFP sequence did not differ significantly. An SSFP sequence provides an excellent method for the 3D whole-heart coronary MRA at 1.5T. Contrast enhanced coronary MRA using the FLASH sequence does not help improve the visibility of coronary segments, image quality, SNR or CNR on the 3D whole-heart coronary MRA.

  9. 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.

  10. 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

    2014-01-01

    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. PMID:25103877

  11. Effect of High Solenoidal Magnetic Fields on Breakdown Voltages of High Vacuum 805 MHz Cavities

    Moretti, A; Geer, S; Qian, Z

    2004-01-01

    The demonstration of muon ionization cooling by a large factor is necessary to demonstrate the feasilibility of a collider or neutrino factory. An important cooling experiment, MICE [1], has been proposed to demonstrate 10 % cooling which will validate the technology. Ionization cooling is accomplished by passing a high-emittance beam in a multi-Tesla solenoidal channel alternately through regions of low Z material and very high accelerating RF Cavities. To determine the effect of very large solenoidal magnetic fields on the generations of Dark current, X-Rays and breakdown Voltage gradients of vacuum RF cavities, a test facility has been established at Fermilab in Lab G. This facility consists of a 12 MW 805 MHz RF station, and a large bore 5 T solenoidal superconducting magnet containing a pill box type Cavity with thin removable window apertures allowing dark current studies and breakdown studies of different materials. The results of this study will be presented. The study has shown that the peak achievab...

  12. Analytical study of induced magnetic and thermal stress in superconducting solenoid

    VECC is in a process of developing an ISOL type of Rare Isotope Beam Facility. After RFQ and Drift Tube Linacs, superconducting QWRs will be employed to accelerate the beam up to 7 MeV/u energy. At present design work has been just initiated for the development of first cryomodule consisting of 4 numbers of superconducting QWR. A superconducting solenoid is planned to put in the middle of the 4 numbers of QWRs for the transverse focusing of the beam. After carrying out preliminary electromagnetic design of the solenoid for producing 9T magnetic field, mechanical design has also been started. Design of the bucking coil has also been carried out for the solenoid so that stray filed at a distance of 200 mm from the centre is less than 30 mT otherwise niobium made cavities of the QWR would have been quenched at underrated electric field gradient. Analytical stress analysis has been carried out to evaluate the stress induced due to magnetic pressure and thermal contraction. Analysis is still in progress to evaluate the necessity of requirement of banding to be carried out with material having higher thermal expansion coefficient so that contact of the extreme layer of the cable has been ensured. Alternative to the provision of availing banding, analysis is underway to take care of the situation by pre-stressing the cable itself during the winding of the coil. (author)

  13. A nonintrusive method for measuring the operating temperature of a solenoid-operated valve

    Experimental data are presented to show that the in-service operating temperature of a solenoid-operated valve (SOV) can be interred simply and nondisruptively by using the copper winding of the solenoid coil as a self-indicating, permanently available resistance thermometer. The principal merits of this approach include (a) there is no need for an add-on temperature sensor, (b) the true temperature of a critical --- and likely the hottest --- part of the SOV (namely, the electrical coil) is measured directly, (c) temperature readout can be provided at any location at which the SOV electrical lead wires are accessible (even though remote from the valve), (d) the SOV need not be disturbed (whether normally energized or deenergized) to measure its temperature in situ, and (e) the method is applicable to all types of SOVs, large and small, ac- and dc-powered. Laboratory tests comparing temperatures measured both by coil resistance and by a conventional thermometer placed in contact with the external surface of the potted solenoid coil indicate that temperature within the coil may be on the order of 40 degree C higher than that measured externally, a fact that is important to life-expectancy calculations made on the basis of Arrhenius theory. Field practicality is illustrated with temperature measurements made using this method on a SOV controlling the flow of refrigerant in a large chilled-water air-conditioning system. 5 refs., 7 figs

  14. Experimental studies of helical solenoid model based on YBCO tape-bridge joints

    Yu, M.; Lombardo, V.; Turrioni, D.; Zlobin, A.V.; /Fermilab; Flangan, G.; /MUONS Inc., Batavia; Lopes, M.L.; /Fermilab; Johnson, R.P.; /Fermilab

    2011-06-01

    Helical solenoids that provide solenoid, helical dipole and helical gradient field components are designed for a helical cooling channel (HCC) proposed for cooling of muon beams in a muon collider. The high temperature superconductor (HTS), 12 mm wide and 0.1 mm thick YBCO tape, is used as the conductor for the highest-field section of HCC due to certain advantages, such as its electrical and mechanical properties. To study and address the design, and technological and performance issues related to magnets based on YBCO tapes, a short helical solenoid model based on double-pancake coils was designed, fabricated and tested at Fermilab. Splicing joints were made with Sn-Pb solder as the power leads and the connection between coils, which is the most critical element in the magnet that can limit the performance significantly. This paper summarizes the test results of YBCO tape and double-pancake coils in liquid nitrogen and liquid helium, and then focuses on the study of YBCO splices, including the soldering temperatures and pressures, and splice bending test.

  15. A nonintrusive method for measuring the operating temperature of a solenoid-operated valve

    Experimental data are presented to show that the in-service operating temperature of a solenoid-operated valve (SOV) can be inferred simply and nondisruptively by using the copper winding of the solenoid coil as a self-indicating, permanently available resistance thermometer. The principal merits of this approach include (a) these is no need for an add-on temperature sensor, (b) the true temperature of a critical - and likely the hottest - part of the SOV (namely, the electrical coil) is measured directly, (c) temperature readout can be provided at any location at which the SOV electrical lead wires are accessible (even though remote from the valve), (d) the SOV need not be disturbed (whether normally energized or deenergized) to measure its temperature in situ, and (e) the method is applicable to all types of SOVs, large and small, ac- and dc-powered. Laboratory tests comparing temperatures measured both by coil resistance and by a conventional thermometer placed in contact with the external surface of the potted solenoid coil indicate that temperature within the coil may be on the order of 40C higher than that measured externally, a fact that is important to life-expectancy calculations made on the basis of Arrhenius theory. Field practicality is illustrated with temperature measurements made using this method on a SOV controlling the flow of refrigerant in a large chilled-water air-conditioning system

  16. Tests of a large air-core superconducting solenoid as a nuclear-reaction-product spectrometer

    An air-core superconducting solenoid, with a diameter of 0.2 m and a length of 0.4 m, has been configured for use as a heavy-ion reaction-product spectrometer (E/A≤5 MeV/u) near θ = 0 0. The spectrometer has a large solid angle (10--35 msr) and properties suitable for time-of-flight measurements with flight paths approx. > 2 m. The performance of the spectrometer was established using α-particle sources and nuclear-reaction products from heavy-ion collisions. The characteristics of air-core magnets are compared to those of steel-yoke magnets. The simplicity and ease of operation of the air-core magnet, without significant problems from the (axial) fringe fields, suggests that larger air-core magnets with dΩ≥20 msr and capable of focusing ions with E/A≥30 MeV/u are feasible. Other applications of solenoids and combinations of solenoids with radial electric-field lenses (ELCO lenses) are also discussed, including designs which focus more than one charge state simultaneously

  17. 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.

  18. Technical specification for the 1.5 Tesla superconducting solenoid for the BaBar detector. Revision 1

    O`Connor, T.G.; Bell, R. [Lawrence Livermore National Lab., CA (United States); Fabbricatore, P. [Istituto Nazionale di Fisica Nucleare, Genoa (Italy); Giorgi, M.; Hitlin, D. [BABAR Collaboration (Italy)

    1997-03-07

    This document sets forth the specification of the BABAR superconducting solenoid and power supply which is being supplied to the BABAR collaboration by INSTITUTO NAZIONALE DI FISICA NUCLEARE (INFN). The solenoid will be installed in the BABAR detector which will be located at Interaction Region 2 (IR2) of the PEP II machine, a positron electron collider, presently under construction at the Stanford Linear Accelerator Center (SLAC) located in Menlo Park, California. The solenoid will become part of the BABAR detector which will be used in SLAC`s high energy physics program. Intense beams of electrons and positrons are made to collide inside the solenoid magnet. High field uniformity quality, precise mechanical alignment and long term stability are essential characteristics of the solenoid. INFN will set up a committee that will provide contractual and technical oversight throughout the design, fabrication and installation phases of the BABAR solenoid construction. That committee will be the final authority to resolve any differences between these specifications and the INFN supplied drawings, in addition to any differences between these specifications or the INFN supplied drawings and the proposals from the vendor. All submissions for approval to INFN whether for design changes, material approval, design submissions or others as required by this specification shall be acted upon INFN within two (2) weeks of receipt of the submissions. If no answer is given the vendor may assume approval and proceed.

  19. Normal appearance of whole-body PET-like imaging at 1.5 T MRI%1.5TMRI全身类PET的正常表现

    李继龙; 张宏斌; 彭荣杰; 杨润; 马雄伟; 李娅妮; 吕妍明; 王东平

    2015-01-01

    目的:探讨1.5 T MRI全身“类PET”的正常表现。材料与方法对40名不同年龄组健康志愿者行1.5 T MR全身“类PET”成像,在AW4.6工作站上经Functool和3D-MIP后处理,获得最大信号强度投影、黑白反转及伪彩“类PET”图像,观察正常组织结构的信号,分析椎体、椎间盘信号信号与年龄的相关性。结果(1)脂肪、肌肉、两肺、肝脏、胃肠道、脑脊液呈低信号;(2)脑、脊髓、头颈部腺体、脾脏、胆囊、生殖腺以及椎间盘呈高信号;(3)椎体在儿童中呈高信号,在60岁以上健康志愿者中主要呈低信号;(4)椎体和椎间盘信号与年龄呈负相关(r=-0.6917,P<0.05;r=-0.7562,P<0.05)。结论正确认识“类PET”的正常表现将有利于对病变的诊断。%Objective: To investigate the normal appearance of whole-body PET-like imaging at 1.5 T MR scanner. Materials and Methods:Forty healthy volunteers with different age underwent whole-body PET-like MR examination at 1.5 T scanner. The data was reformatted using Functool and 3D-MIP software at AW4.6 workstation. Then, maximum intensity projection (MIP), inverted-gray-scale and pseudocolor processing PET-like images were obtained. Signal of the normal tissue was observed. Correlation between age and signal of lumbar vertebrae and intervertebral discs was analyzed. Results:(1) Fat, muscle, lungs, liver, gastrointestinal tract, and cerebrospinal fluid showed hypointensity. (2) Brain, spinal cord, glands of head and neck, spleen, gallbladder, genital gland, and intervertebral discs showed hyperintensity. (3) Vertebral body showed hyperintensity in children and mainly hypointensity in healthy volunteers over 60 years of age. (4) There were significant negative correlation between age and signal of lumbar vertebrae (r=-0.6917,P<0.05) and intervertebral discs (r=-0.7562,P<0.05). Conclusions: It will be beneifcial for diagnosis after correctly understanding normal appearance of PET-like images.

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

    Chabanova, E.; Balslev, I.; Løgager, Vibeke Berg;

    2010-01-01

    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...

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

    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.

  2. 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.

  3. Specificity of choline metabolites for in vivo diagnosis of breast cancer using {sup 1}H MRS at 1.5 T

    Stanwell, Peter; Gluch, Laurence; Lean, Cynthia; Malycha, Peter; Mountford, Carolyn [Royal North Shore Hospital, Institute for Magnetic Resonance Research and Department of Magnetic Resonance in Medicine, University of Sydney, St Leonards, NSW (Australia); Clark, David [Breast Centre, Waratah, NSW (Australia); Tomanek, Boguslaw [National Research Council Canada, Institute for Biodiagnostics, Winnipeg, MB (Canada); Baker, Luke [Sydney Adventist Hospital, Department of Radiology, Wahroonga, NSW (Australia); Giuffre, Bruno [Royal North Shore Hospital, Department of Radiology, St Leonards, NSW (Australia)

    2005-05-01

    The purpose was to determine if in vivo proton magnetic resonance spectroscopy ({sup 1}H MRS) at 1.5 T can accurately provide the correct pathology of breast disease. Forty-three asymptomatic volunteers including three lactating mothers were examined and compared with 21 breast cancer patients. Examinations were undertaken at 1.5 T using a purpose-built transmit-receive single breast coil. Single voxel spectroscopy was undertaken using echo times of 135 and 350 ms. The broad composite resonance at 3.2 ppm, which includes contributions from choline, phosphocholine (PC), glycerophosphocholine (GPC), myo-inositol and taurine, was found not to be a unique marker for malignancy providing a diagnostic sensitivity and specificity of 80.0 and 86.0%, respectively. This was due to three of the asymptomatic volunteers and all of the lactating mothers also generating the broad composite resonance at 3.2 ppm. Optimised post-acquisitional processing of the spectra resolved a resonance at 3.22 ppm, consistent with PC, in patients with cancer. In contrast the spectra recorded for three false-positive volunteers, and the three lactating mothers had a resonance centred at 3.28 ppm (possibly taurine, myo-inositol or GPC). This improved the specificity of the test to 100%. Careful referencing of the spectra and post-acquisitional processing intended to optimise spectral resolution of in vivo MR proton spectra from human breast tissue resolves the composite choline resonance. This allows the distinction of patients with malignant disease from volunteers with a sensitivity of 80% and specificity of 100%. Therefore, resolution of the composite choline resonance into its constituent components improves the specificity of the in vivo {sup 1}H MRS method, but does not overcome the problem of 20% false-negatives. (orig.)

  4. 31P-MR spectroscopy of all regions of the human heart at 1.5 T with acquisition-weighted chemical shift imaging

    Aim: Aim of this study was to show whether or not acquisition-weighted chemical shift imaging (AW-CSI) allows the determination of PCr and ATP in the lateral and posterior wall of the human heart at 1.5 T. Methods: 12 healthy volunteers were examined using a conventional chemical shift imaging (CSI) and an AW-CSI. The sequences differed only in the number of repetitions for each point in k space. A hanning function was used as filter function leading to 7 repetitions in the center of the k space and 0 in the corners. Thus, AW-CSI had the same resolution as the CSI sequence. The results for both sequences were analyzed using identically positioned voxels in the septal, anterior, lateral and posterior wall. Results: The determined averaged AW-CSI signal to noise ratios were higher for PCr by a factor of 1.3 and for ATP by 1.4 than those of CSI. The PCr/ATP ratios were higher by a factor of 1.2 - 1.3 and showed a smaller standard deviation in all locations for AW-CSI. The mean PCr/ATP ratios determined by AW-CSI of septal, lateral and posterior wall were almost identical (1.72 - 1.76), while it was higher in the anterior wall (1.9). Conclusions: The reduced contamination in AW-CSI improves the signal to noise ratio and the determination of the PCr/ATP ratio in cardiac 31P spectroscopy compared to CSI with the same resolution. The results in volunteers indicate that AW-CSI renders 31P spectroscopy of the lateral and posterior wall of the human heart feasible for patient studies at 1.5 T. (orig.)

  5. Cool-down, static heat load and warm-up performance of the central solenoid model coil and the central solenoid insert model coil

    In International Thermonuclear Experimental Reactor (ITER) Engineering Design Activities, the Central Solenoid model Coil (CSMC) and the CS Insert Coil (CSIC) have been fabricated, and installed into the ITER CSMS test facility at Naka Fusion Establishment, Japan Atomic Energy Research Institute (JAERI). The CSMS and CSIC conductors are applied to the cable-in-conduit conductors cooled by forced-flow supercritical helium (SHe) at 4.5 K. There are 48 parallel cooling channels for the CSMC, the CSIC and the structures. In the CSMC experiment, the cool-down and the warm-up were finished successfully. The cool-down time was within 480 hours. The steady head load without coil current was measured and evaluated. (author)

  6. Comparison analysis of superconducting solenoid magnet systems for ECR ion source based on the evolution strategy optimization

    Wei, Shao Qing; Lee, Sang Jin [Uiduk University, Gyeongju (Korea, Republic of)

    2015-06-15

    Electron cyclotron resonance (ECR) ion source is an essential component of heavy-ion accelerator. For a given design, the intensities of the highly charged ion beams extracted from the source can be increased by enlarging the physical volume of ECR zone. Several models for ECR ion source were and will be constructed depending on their operating conditions. In this paper three simulation models with 3, 4 and 6 solenoid system were built, but it's not considered anything else except the number of coils. Two groups of optimization analysis are presented, and the evolution strategy (ES) is adopted as an optimization tool which is a technique based on the ideas of mutation, adaptation and annealing. In this research, the volume of ECR zone was calculated approximately, and optimized designs for ECR solenoid magnet system were presented. Firstly it is better to make the volume of ECR zone large to increase the intensity of ion beam under the specific confinement field conditions. At the same time the total volume of superconducting solenoids must be decreased to save material. By considering the volume of ECR zone and the total length of solenoids in each model with different number of coils, the 6 solenoid system represented the highest coil performance. By the way, a certain case, ECR zone volume itself can be essential than the cost. So the maximum ECR zone volume for each solenoid magnet system was calculated respectively with the same size of the plasma chamber and the total magnet space. By comparing the volume of ECR zone, the 6 solenoid system can be also made with the maximum ECR zone volume.

  7. Preliminary study of 1.5 T MR guided radio-frequency ablation for hepatic malignant tumors%1.5 T MR导向下肝脏恶性肿瘤射频消融治疗技术初探

    林征宇; 张涛; 胡建平; 邓秀芬

    2010-01-01

    目的 探讨1.5 T MR引导下对肝脏恶性肿瘤射频消融治疗的可行性.方法 23例44个经病理证实、不能或不愿手术的肝脏恶性肿瘤病灶,其中11例为原发性肝癌、12例为肝转移癌,肿瘤最大径平均(3.3±1.8)cm,均采用MR兼容多极射频针在1.5 T MR引导下进行射频消融治疗.术后MR扫描观察消融情况,消融灶完全覆盖原病灶、范围超出病灶边缘0.5~1.0 cm为消融完全.结果 所有消融均顺利完成,平均手术时间(93±33)min,消融灶均完全覆盖病灶,无胆瘘、膈肌穿孔、黄疸、气胸等并发症发生.射频电极针在MR图像上呈低信号.消融灶在T2WI序列上呈低信号,周围可见薄层高信号环绕;T1WI序列上消融灶呈明显高信号,边界清晰;DWI上消融灶呈等低信号,周围呈环状稍高信号.结论 1.5 T MR引导下肝脏恶性肿瘤射频消融是安全、有效的技术.%Objective To explore the technique and feasibility of using 1.5 T MR guided radiofrequency ablation (RFA) of hepatic malignant tumor. Methods Twenty three patients with 44 malignant lesions in liver confirmed by pathology were treated with 1.5 T MR guided RFA using MR compatible multipolar RF electrode. Only patients refusing open surgery or suffering from unresectable lesions were included. Of these, 11 patients had primary hepatic carcinoma and 12 patients had hepatic metastases. The mean maximal diameter of lesions was (3.3 ± 1.8)cm. Postoperative MR was performed; the ablation zone covered and exceeded 0.5 to 1.0 cm to the margin of initial tumor was considered successful. Results All ablations were successful and lesions created by radio frequency were large enough to cover the initial tumor volume in all cases. No severe complications such as biliary fistula, perforation of diaphragmatic muscle,postoperative jaundice and pneumothorax were encountered. The mean operative time was (93 ± 33 ) min.The RF electrodes appeared in MRI as low signal structure. The ablation lesions were well-defined hyperintensity in T1 WI and hypo-intensity with a thin rim of high signal intensity on T2WI and DWI. Conclusion 1.5 T MR guided RFA of hepatic malignant tumor is an effective and safe technique.

  8. Endometriose pélvica: comparação entre imagens por ressonância magnética de baixo campo (0,2 T) e alto campo (1,5 T) Pelvic endometriosis: a comparison between low-field (0.2 T) and high-field (1.5 T) magnetic resonance imaging

    Karine Minaif; David Carlos Shigueoka; Cintia Cristina Satie Minami; Danilo Moulin Sales; José Maria Cordeiro Ruano; Alberto Sinhiti Noguti; Sergio Ajzen; Jacob Szejnfeld

    2008-01-01

    OBJETIVO: Comparar a ressonância de baixo campo (0,2 T) com a de alto campo (1,5 T) na avaliação da endometriose pélvica e adenomiose. MATERIAIS E MÉTODOS: Foram estudadas, prospectivamente, 27 pacientes do sexo feminino com suspeita clínica de endometriose, realizando-se exames de ressonância magnética de alto campo e baixo campo. Um mesmo radiologista realizou a leitura dos exames, iniciando pelo baixo campo, seguido pelo alto campo, usando como padrão-ouro o alto campo. RESULTADOS: Das 27 ...

  9. Diffusion tensor imaging of the brain in a healthy adult population: Normative values and measurement reproducibility at 3 T and 1.5 T

    Brander, Antti; Kataja, Anneli; Saastamoinen, Antti; Ryymin, Pertti; Soimakallio, Seppo; Dastidar, Prasun (Dept. of Radiology, Tampere Univ. Hospital, Tampere (Finland), e-mail: antti.brander@pshp.fi); Huhtala, Heini (School of Public Health, Tampere Univ., Tampere (Finland)); Oehman, Juha (Dept. of Neurosciences and Rehabilitation, Tampere Univ. Hospital, Tampere (Finland))

    2010-09-15

    Background: Diffusion tensor imaging (DTI) is an increasingly used method for investigation of brain white matter integrity in both research and clinical applications. Familiarity with normal variation of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and measurement reproducibility is essential when DTI measurements are interpreted in clinical patients. Purpose: To establish normal values for FA and ADC in a healthy adult population at 1.5 T and 3 T MRI based on region of interest (ROI) analysis, and to study the inter- and intra-observer reproducibility of the measurements. Material and Methods: Forty healthy volunteers (26 women, 14 men, mean age 38.3, SD 11.6 years) underwent conventional MRI and DTI of the brain, 30 with 3 T and 10 with 1.5 T clinical scanners. ROI-based measurements for FA and ADC values were performed in five different anatomic locations of each hemisphere and in three locations within the corpus callosum. Mean values for FA and ADC for each region were calculated. Inter-observer variation of ROI measurements was evaluated by comparing the results of the two observers, intra-observer variation by repeated measurement of 10 subjects by both observers. Results: The FA values varied considerably between different regions. The highest values were found in the genu and splenium of the corpus callosum and the lowest in the corona radiata, respectively. In general, ADC values showed less variation; the highest values were found in the body of the corpus callosum and the lowest in the corona radiata. The reproducibility of both inter- and intra-observer measurements also varied regionally. The highest agreement was found for the corpus callosum and the lowest for the corona radiata and centrum semiovale. Conclusion: In a normal adult population FA and ADC values of the brain white matter show regional variation. The repeatability of the ROI measurements also varies regionally. This regional variability must be acknowledged when these measurements are interpreted in clinical patients. Keywords Brainstem, CNS, diffusion imaging, MRI

  10. Design of a gate-turn-off (GTO) switch for pulsed power application

    A Gate-Turn-Off (GTO) thyristor switch and its gate drive circuit have been developed as a replacement for the thyratron switch used in the positron converter solenoid lens power supply at the Advanced Photon Source (APS) to deliver a current pulse of 6000 A at 60-Hz repetition rate. This paper discusses the characteristics of the GTOs under consideration, the gate drive circuit, and some test results

  11. Build up of electron cloud with different bunch pattern in the presence of solenoid field

    We have augmented the code POSINST to include solenoid fields, and used it to simulate the build up of electron cloud due to electron multipacting in the PEP-II positron ring. We find that the distribution of electrons is strongly affected by the resonances associated with the cyclotron period and bunch spacing. In addition, we discover a threshold beyond which the electron density grows exponentially until it reaches the space charge limit. The threshold does not depend on the bunch spacing but does depend on the positron bunch population

  12. Buildup of electron cloud with different bunch pattern in the presence of solenoid field

    We have augmented the code POSINST to include solenoid fields, and used it to simulate the build up of electron cloud due to electron multipacting in the PEP-II positron ring. We find that the distribution of electrons is strongly affected by the resonances associated with the cyclotron period and bunch spacing. In addition, we discover a threshold beyond which the electron density grows exponentially until it reaches the space charge limit. The threshold does not depend on the bunch spacing but does depend on the positron bunch population

  13. Nano-solenoid: helicoid carbon-boron nitride hetero-nanotube

    Zhang, Zi-Yue; Miao, Chunyang; Guo, Wanlin

    2013-11-01

    As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid can generate a uniform and tremendous magnetic field of more than 1 tesla, closing to that generated by the main magnet of medical nuclear magnetic resonance. Moreover, the magnitude of magnetic field can be easily modulated by bias voltage, providing great promise for a nano-inductor to realize electromagnetic conversion at the nanoscale.As a fundamental element of a nanoscale passive circuit, a nano-inductor is proposed based on a hetero-nanotube consisting of a spiral carbon strip and a spiral boron nitride strip. It is shown by density functional theory associated with nonequilibrium Green function calculations that the nanotube exhibits attractive transport properties tunable by tube chirality, diameter, component proportion and connection manner between the two strips, with excellent `OFF' state performance and high current on the order of 10-100 μA. All the hetero-nanotubes show negative differential resistance. The transmission peaks of current are absolutely derived from the helicoid carbon strips or C-BN boundaries, giving rise to a spiral current analogous with an energized nano-solenoid. According to Ampere's Law, the energized nano-solenoid

  14. Sampled Data Control of a Compliant Actuated Joint Using On/Off Solenoid Valves

    N. G. Tsagarakis

    2011-01-01

    Full Text Available This paper proposes a new control system design method for a compliant actuated joint using on/off solenoid valves. Themathematical modelling and the system’s hardware are described in detail. The control design method is presented in ageneral manner so it could be applied for any other similar system. For the present system, the designed controller is implementedvia a digital computer and it is characterised by very good performance and simplicity. The success of the proposedmethod is validated via simulations and experiment.

  15. Solenoid coil for mouse-model MRI with a clinical 3-Tesla imager: body imaging

    Hidalgo, S. S.; D. Jirak; S.E. Solis; Rodríguez, A.O.

    2009-01-01

    A solenoid coil was built for magnetic resonance imaging of the mice. A coil prototype composed of 5 turns, with a length of 4 cm and 2.5 cm radius was developed to acquire (whole) body mouse magnetic resonance images at 130 MHz and an insertable gradient coil set. Coil performance was measured using the Q factor for both the loaded and unloaded cases were 161.67 and 178.03, respectively. These Q factors compare very well with those values reported in the literature. The images were acquired ...

  16. Conceptual design of a 2 tesla superconducting solenoid for the Fermilab D{O} detector upgrade

    Brzezniak, J.; Fast, R.W.; Krempetz, K.

    1994-05-01

    This paper presents a conceptual design of a superconducting solenoid to be part of a proposed upgrade for the D0 detector. This detector was completed in 1992, and has been taking data since then. The Fermilab Tevatron had scheduled a series of luminosity enhancements prior to the startup of this detector. In response to this accelerator upgrade, efforts have been underway to design upgrades for D0 to take advantage of the new luminosity, and improvements in detector technology. This magnet is conceived as part of the new central tracking system for D0, providing a radiation-hard high-precision magnetic tracking system with excellent electron identification.

  17. The silicon sensor for the compact muon solenoid tracker. Control of the fabrication process

    The Compact Muon Solenoid (CMS) is one of the experiments at the Large Hadron Collider (LHC) under construction at CERN. The inner tracking system of this experiment consists of the world largest Silicon Strip Tracker (SST). In total, 24,244 silicon sensors are implemented covering an area of 206 m2. To construct this large system and to ensure its functionality for the full lifetime of ten years under the hard LHC condition, a detailed quality assurance program has been developed. This paper describes the strategy of the Process Qualification Control to monitor the stability of the fabrication process throughout the production phase and the results obtained are shown. (authors)

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

    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

  19. 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.

  20. Build up of Electron Cloud with Different Bunch Pattern in the Presence of Solenoid Field

    We have augmented the code POSINST to include solenoid fields, and used it to simulate the build up of electron cloud due to electron multipacting in the PEP-II positron ring. We find that the distribution of electrons is strongly affected by the resonances associated with the cyclotron period and bunch spacing. In addition, we discover a threshold beyond which the electron density grows exponentially until it reaches the space charge limit. The threshold does not depend on the bunch spacing but does depend on the positron bunch population

  1. Simulation of adiabatic thermal beams in a periodic solenoidal magnetic focusing field

    Barton, T. J.; Field, David M.; Lang, Kevin M.; Chen, C.

    2012-01-01

    Self-consistent particle-in-cell simulations are performed to verify earlier theoretical predictions of adiabatic thermal beams in a periodic solenoidal magnetic focusing field [ K. R. Samokhvalova, J. Zhou and C. Chen Phys. Plasmas 14 103102 (2007); J. Zhou, K. R. Samokhvalova and C. Chen Phys. Plasmas 15 023102 (2008)]. In particular, results are obtained for adiabatic thermal beams that do not rotate in the Larmor frame. For such beams, the theoretical predictions of the rms beam envelope,...

  2. 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...

  3. Photon Production From The Scattering of Axions Out of a Solenoidal Magnetic Field

    Guendelman, Eduardo I; Cantatore, Giovanni; Zioutas, Konstantin

    2009-01-01

    In this paper we calculate the total cross section for the production of photons from the scattering of axions by a strong inhomogeneous magnetic field in the form of a cylindrical step function and a 2D delta function, which can be approximately produced by a solenoidal current. The theoretical result is used to estimate the total number of events and the axion-photon conversion probability which could be expected in a reasonable experimental situation. The calculated conversion probabilities for QCD inspired axions are much larger than those derived by applying the celebrated 1D calculation of the (inverse) coherent Primakoff effect.

  4. Investigation, development and verification of printed circuit board embedded air-core solenoid transformers

    Mønster, Jakob Døllner; Madsen, Mickey Pierre; Pedersen, Jeppe Arnsdorf; Knott, Arnold

    A new printed circuit board embedded air-core transformer/coupled inductor is proposed and presented. The transformer is intended for use in power converter applications operating at very high frequency between 30 MHz to 300 MHz. The transformer is based on two or more solenoid structures in...... prototypes. The analytical model shows good agreement with the measured results. The model can predict the inductive parameters of the transformer with a deviation range of approximately 3 % to 22 %. Lastly a prototype is used in a VHF converter to achieve a rise of 2.2% points in efficiency....

  5. The silicon sensors for the Compact Muon Solenoid tracker—design and qualification procedure

    Agram, J.-L.; Angarano, M. M.; Assouak, S.; Bergauer, T.; Bilei, G. M.; Borrello, L.; Brianzi, M.; Civinini, C.; Dierlamm, A.; Dinu, N.; Demaria, N.; Feld, L.; Focardi, E.; Fontaine, J.-C.; Forton, E.; Furgeri, A.; Gregoire, Gh.; Hartmann, F.; Honma, A.; Juillot, P.; Kartashov, D.; Krammer, M.; Macchiolo, A.; Mannelli, M.; Messineo, A.; Migliore, E.; Militaru, O.; Piasecki, C.; Santinelli, R.; Sentenac, D.; Servoli, L.; Starodumov, A.; Tonelli, G.; Wang, J.

    2004-01-01

    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 24,244 silicon sensors covering an area of 206 m2. To construct a large system of this size and ensure its functionality for the full lifetime of 10 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.

  6. 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.

  7. 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.

  8. Estudio de alternativas para el accionamiento de solenoides utilizados en impresoras Braille

    Boyano Vannucchi, Leandro E.

    2006-01-01

    La realización de este proyecto se ha llevado a cabo en el grupo de Sistemas Electrónicos de Potencia, perteneciente al Departamento de Tecnología Electrónica. El objetivo principal del mismo consiste en mejorar el funcionamiento de las impresoras Braille de tipo impacto. La denominación de la impresora se debe a que el carácter Braille impreso se obtiene por el impacto de un elemento metálico sobre el papel. Este elemento electro-mecánico se llama solenoide (conocido también como martillo el...

  9. 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.

  10. Neutron diffraction study in pulsed high magnetic field

    We have developed a technique for neutron diffraction experiments in pulsed high magnetic fields to determine magnetic structures in high field. Our system is capable to produce pulsed fields up to 20 T every 2 sec. The experiment was done using MRP diffractmeter at KENS. The magnet was the so-called Bitter type water cooling solenoid with 40 mm inner diameter, 240 mm outer diameter and 220 mm length. It was horizontally installed on the goniometer. The flow type FRP cryostat was set in the magnet and the temperature was down to almost 4.2 K but there was a heating problem for metal sample when a pulsed magnetic field was applied. The first application has been done for a determination of high field magnetic structure of metamagnetic PrCo2Si2. (author)

  11. 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.

  12. Evaluation of RF heating on humerus implant in phantoms during 1.5T MR imaging and comparisons with electromagnetic simulation

    The purpose of this study was to evaluate the effect of radiofrequency (RF) heating on a metallic implant during magnetic resonance imaging (MRI), temperatures at several positions of an implant were measured, and results are compared with electromagnetic simulations using a finite element method. A humerus nail implant made of stainless steel was embedded at various depths of tissue-equivalent gel-phantoms with loop (loop phantom) and partially cut loop (loop-cut phantom), and the phantoms were placed parallel to the static magnetic field of a 1.5T MRI device. Scans were conducted at maximum RF for 15 min, and temperatures were recorded with 2 RF-transparent fiberoptic sensors. Finally, electromagnetic-field analysis was performed. Temperatures increased at both ends of the implants at various depths, and temperature increase was suppressed with increasing depth. The maximum temperature rise was 12.3 deg C at the tip of the implant and decreased for the loop-cut phantom. These tendencies resembled the results of electromagnetic simulations. RF heating was verified even in a nonmagnetizing metal implant in a case of excessive RF irradiation. Particularly, rapid temperature rise was observed at both ends of the implant having large curvatures. The difference in temperature increase by depth was found to reflect the skin-depth effect of RF intensity. Electromagnetic simulation was extremely useful for visualizing the eddy currents within the loop and loop-cut phantoms and for evaluating RF heating of a metallic implant for MRI safety. (author)

  13. Phase diagram for the first peak in torque curves of YBa2Cu4O8 crystals up to 15 T

    Torque measurements on single crystals of YBa2Cu4O8 show multiple peaks as a function of angle θ ca between the c-axis and the magnetic field H in the c-a plane. We propose that the first peaks at θ ca (90 - 10) deg. and (90 + 10) deg. arise from a long-range spiral spin density wave through the matching pinning between vortices and spins. We construct a contour map for a competing order parameter in YBa2Cu4O8 which starts at a finite magnetic field and is located far from the upper critical field line. We extended our torque measurements up to 15 T. The regime of the proposed spin density wave goes to higher temperatures when field increases. The first peak does not appear when the field direction is scanned in the c-b plane. We interpret that the origin of the first peak is due to the Zeeman effect between spiral spins and vortices. The NMR line width of the c-axis aligned YBa2Cu4O8 powders in H perpendicular c shows broadening at temperatures below 30 K, and may be caused by the proposed spin density wave. We consider that these features are able to be observed only for the cleanest underdoped cuprate

  14. Phase diagram for the first peak in torque curves of YBa{sub 2}Cu{sub 4}O{sub 8} crystals up to 15 T

    Ishida, Takekazu [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan) and JST-CREST, 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012 (Japan)]. E-mail: ishida@center.osakafu-u.ac.jp; Katayama, Kazumasa [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); JST-CREST, 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012 (Japan); Satoh, Koji [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); JST-CREST, 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012 (Japan); Yoshida, Yuzo [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); JST-CREST, 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012 (Japan); Kawamata, Shuichi [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531 (Japan); JST-CREST, 4-1-8, Honcho, Kawaguchi City, Saitama Pref. 332-0012 (Japan); Sasaki, Takahiko [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Kobayashi, Norio [Institute for Material Research, Tohoku University, Sendai 980-8577 (Japan); Adachi, Seiji [SRL-ISTEC, 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135-0062 (Japan); Machi, Takato [SRL-ISTEC, 10-13 Shinonome 1-chome, Koto-ku, Tokyo 135-0062 (Japan)

    2005-10-01

    Torque measurements on single crystals of YBa{sub 2}Cu{sub 4}O{sub 8} show multiple peaks as a function of angle {theta} {sub ca} between the c-axis and the magnetic field H in the c-a plane. We propose that the first peaks at {theta} {sub ca} (90 - 10) deg. and (90 + 10) deg. arise from a long-range spiral spin density wave through the matching pinning between vortices and spins. We construct a contour map for a competing order parameter in YBa{sub 2}Cu{sub 4}O{sub 8} which starts at a finite magnetic field and is located far from the upper critical field line. We extended our torque measurements up to 15 T. The regime of the proposed spin density wave goes to higher temperatures when field increases. The first peak does not appear when the field direction is scanned in the c-b plane. We interpret that the origin of the first peak is due to the Zeeman effect between spiral spins and vortices. The NMR line width of the c-axis aligned YBa{sub 2}Cu{sub 4}O{sub 8} powders in H perpendicular c shows broadening at temperatures below 30 K, and may be caused by the proposed spin density wave. We consider that these features are able to be observed only for the cleanest underdoped cuprate.

  15. Pelvic endometriosis: a comparison between low-field (0.2 T) and high-field (1.5 T) magnetic resonance imaging

    Objective: to compare low-field (0.2 T) with high-field (1.5 T) magnetic resonance imaging in the assessment of pelvic endometriosis and adenomyosis. Materials and methods: twenty-seven female patients with clinically suspected endometriosis were prospectively evaluated by means of high-field and low-field magnetic resonance imaging. The reading of the images was performed by a single radiologist, initiating by the low-field, followed by the high-field images. High-field magnetic resonance imaging was utilized as the golden-standard. Results: among the 27 patients included in the present study, 18 (66.7%) had some type of lesion suggesting the presence of endometriosis demonstrated at high-field images. In 14 of these patients the diagnosis was correctly established by low-field magnetic resonance imaging. Endometriomas, tubal lesions, and endometriotic foci > 7 mm identified at the high-field images were also identified at low-field images with 100% accuracy, sensitivity and specificity. Among the nine patients diagnosed with adenomyosis by high-field images, eight were correctly diagnosed by low-field images with 88.9% accuracy, specificity and sensitivity. Conclusion: low-field magnetic resonance imaging demonstrated a low sensitivity in the detection of small endometriotic foci, high sensitivity in the detection of endometriomas and large endometriotic foci, and high accuracy in the detection of adenomyosis when compared with high-field magnetic resonance imaging. (author)

  16. Pelvic endometriosis: a comparison between low-field (0.2 T) and high-field (1.5 T) magnetic resonance imaging

    Minaif, Karine; Ajzen, Sergio [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis]. E-mail: kminaif@uol.com.br; Shigueoka, David Carlos; Minami, Cintia Cristina Satie; Sales, Danilo Moulin; Szejnfeld, Jacob [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of Imaging Diagnosis. Unit of Abdomen; Ruano, Jose Maria Cordeiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of General Gynecology. Sector of Videlaparoscopy; Noguti, Alberto Sinhiti [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. of General Gynecology

    2008-11-15

    Objective: to compare low-field (0.2 T) with high-field (1.5 T) magnetic resonance imaging in the assessment of pelvic endometriosis and adenomyosis. Materials and methods: twenty-seven female patients with clinically suspected endometriosis were prospectively evaluated by means of high-field and low-field magnetic resonance imaging. The reading of the images was performed by a single radiologist, initiating by the low-field, followed by the high-field images. High-field magnetic resonance imaging was utilized as the golden-standard. Results: among the 27 patients included in the present study, 18 (66.7%) had some type of lesion suggesting the presence of endometriosis demonstrated at high-field images. In 14 of these patients the diagnosis was correctly established by low-field magnetic resonance imaging. Endometriomas, tubal lesions, and endometriotic foci > 7 mm identified at the high-field images were also identified at low-field images with 100% accuracy, sensitivity and specificity. Among the nine patients diagnosed with adenomyosis by high-field images, eight were correctly diagnosed by low-field images with 88.9% accuracy, specificity and sensitivity. Conclusion: low-field magnetic resonance imaging demonstrated a low sensitivity in the detection of small endometriotic foci, high sensitivity in the detection of endometriomas and large endometriotic foci, and high accuracy in the detection of adenomyosis when compared with high-field magnetic resonance imaging. (author)

  17. Diagnostic performance of CT-arthrography and 1.5T MR-arthrography for the assessment of glenohumeral joint cartilage: a comparative study with arthroscopic correlation

    Omoumi, Patrick [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Lausanne University Hospital, Department of Radiology, Lausanne (Switzerland); Rubini, Alexandra; Berg, Bruno C. vande; Lecouvet, Frederic E. [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Radiology, Brussels (Belgium); Dubuc, Jean-Emile [Cliniques Universitaires St Luc - Universite Catholique de Louvain, Department of Orthopedic Surgery, Brussels (Belgium)

    2015-04-01

    To compare the diagnostic performance of multi-detector CT arthrography (CTA) and 1.5-T MR arthrography (MRA) in detecting hyaline cartilage lesions of the shoulder, with arthroscopic correlation. CTA and MRA prospectively obtained in 56 consecutive patients following the same arthrographic procedure were independently evaluated for glenohumeral cartilage lesions (modified Outerbridge grade ≥2 and grade 4) by two musculoskeletal radiologists. The cartilage surface was divided in 18 anatomical areas. Arthroscopy was taken as the reference standard. Diagnostic performance of CTA and MRA was compared using ROC analysis. Interobserver and intraobserver agreement was determined by κ statistics. Sensitivity and specificity of CTA varied from 46.4 to 82.4 % and from 89.0 to 95.9 % respectively; sensitivity and specificity of MRA varied from 31.9 to 66.2 % and from 91.1 to 97.5 % respectively. Diagnostic performance of CTA was statistically significantly better than MRA for both readers (all p ≤ 0.04). Interobserver agreement for the evaluation of cartilage lesions was substantial with CTA (κ = 0.63) and moderate with MRA (κ = 0.54). Intraobserver agreement was almost perfect with both CTA (κ = 0.94-0.95) and MRA (κ = 0.83-0.87). The diagnostic performance of CTA and MRA for the detection of glenohumeral cartilage lesions is moderate, although statistically significantly better with CTA. (orig.)

  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. Comparison of T2-weighted and contrast-enhanced T1-weighted MR imaging at 1.5 T for assessing the local extent of cervical carcinoma

    To compare two MR sequences at 1.5 T - T2-weighted and contrast-enhanced T1-weighted images - by using macroscopic sections to determine which image type enables the most accurate assessment of cervical carcinoma. Forty consecutive patients (mean age, 39.2 years) with biopsy-proven cervical carcinoma were included. Each MR sequence was assessed for tumour localisations, tumour margins, and cancer extent with the consensus of two readers, and tumour margins were rated on a five-point scale. MR findings were correlated with histopathological findings. Contrast-to-noise ratios (CNRs) obtained with each image were compared using nonparametric tests. Thirty-one of 40 patients underwent hysterectomies and nine of 40 underwent trachelectomies. In 36 patients, lesions were identified on at least one sequence. The tumours at stage 1B or higher were detected in 94.7% on contrast-enhanced T1-weighted images and in 76.3% on T2-weighted images (P < 0.05). Tumour margins appeared significantly more distinct on contrast-enhanced T1-weighted images than on T2-weighted images (P < 0.001). The CNRs obtained using contrast-enhanced T1-weighted images were significantly higher (P < 0.001) than those obtained using T2-weighted images. Contrast-enhanced T1-weighted imaging is more useful for assessing cervical carcinoma than T2-weighted imaging. (orig.)

  20. 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.

  1. 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...

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

    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.)

  3. An investigation of cerebral magnetic resonance angiography (MRA), part 9. Diagnostic ability of intracranial occlusive vessels with MRA using 1.5 T MRI

    Using three-dimensional time-of-flight (3D TOF) MRA with a 1.5 T MRI system, we assessed the capability of MRA to detect intracranial occlusive lesions. Ten observers evaluated MRA images of 78 patients (including 33 cases with 57 intracranial occlusive lesions) using maximum intensity projection (MIP) images alone, MIP+selective MIP images, and MIP+selective MIP+original images. By receiver operating characteristic (ROC) analysis of the ability to detect the 33 patients with occlusive lesions, the sensitivity of MIP images was 89±7% (mean ±S. D.) while the specificity was 80%. The sensitivity was significantly higher than that for detecting aneurysms (74±8%). Adding selective MIP and original images to MIP images did not improve the sensitivity in detecting occlusive lesions. Sensitivity for detection of severe stenosis and occlusion was over 75%, which was considered to be satisfactory to identity the lesions, while that for mild stenosis was 44%. Although the sensitivity did not show any difference between internal coroted (IC) and middle cerebral artery stenosis (MCA), false positive IC lesions were more frequent. These results indicate that the sensitivity of MRA in detecting occlusive lesions is generally satisfactory, while care should be taken in diagnosing mild stenotic lesions and lesions in the IC. (author)

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

    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.

  5. MRI of knee joint: first results of a comparison of a 0.2 T dedicated system with a 1.5 T high field strength magnet; MRT des Kniegelenks: Erste Ergebnisse eines Vergleichs von 0,2-T-Spezialsystem mit 1,5-T-Hochfeldmagnet

    Kersting-Sommerhoff, B. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Gerhardt, P. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Golder, W. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Hof, N. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Riel, K.A. [Abt. fuer Sporttraumatologie, Orthopaedische Klinik, Klinikum der Technischen Univ. Muenchen (Germany); Helmberger, H. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Lenz, M. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany); Lehner, K. [Inst. fuer Roentgendiagnostik, Klinikum der TU Muenchen (Germany)

    1995-05-01

    Diagnostic accuracy and image quality of a specialised system for MR examinations of peripheral joints were evaluated. 20 patients with acute or chronic injuries of the knee were examined using a low-field MR system (0.2 T). For comparison, all patients were also studied with a 1.5 T high field strength magnet and all diagnoses were correlated with arthroscopic findings. We found compatible diagnostic accuracies (cruciate ligaments 90%, menisci 75-90%) and good image quality ratings for the low field system (`good` and `excellent` image quality in 83% of cases). (orig./MR) [Deutsch] Ein Spezialsystem zur MR-Diagnostik von peripheren Gelenkerkrankungen wurde auf diagnostische Treffsicherheit und Bildqualitaet untersucht. 20 Patienten mit akuten oder chronischen Kniegelenkslaesionen wurden in einem Niederfeld-Spezialsystem (0,2 T) sowie vergleichend in einem Hochfeldgeraet (1,5 T) kernspintomographisch untersucht. Alle Befunde wurden arthroskopisch ueberprueft. Es fanden sich vergleichbare diagnostische Trefsicherheiten (Kreuzbandlaesionen 90%, Meniskuslaesionen 75-90%) sowie eine gute Bildqualitaet (83% der Studien wurden als `gut` oder `sehr gut` beurteilt) des Niederfeldgeraetes. (orig./MG)

  6. 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)

  7. Design and experimental results of the Nb3Sn double insert for an 18 tesla, 100 mm free bore solenoid

    A high field, large free bore (more than 100 mm at 4.2 K) solenoid for the LASA Lab of INFN-Milan is almost completed. The Nb3Sn insert, constituted by two coils independently supplied, is designed to provide a central field in excess of 18 tesla when immersed in the background field of 8 tesla when immersed in the background field of 8 tesla generated by a NbTi solenoid of 550 mm room temperature bore (this last solenoid already being in operation). The construction technique--W and R followed by vacuum impregnation--is described and the results of tests and measurements carried out on models wound with the real conductor (a NbSn/Cu Rutherford flat cable) are reported

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

    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

  9. 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.

  10. Ion beam transport and focus for LMF using an achromatic solenoidal lens system

    The light ion LMF (Laboratory Microfusion Facility) requires an ion beam transport length for bunching and standoff to be about four meters from the diode to the target. The baseline LMF transport scheme uses an achromatic two lens system consisting of the diode (a self-field lens) and a solenoidal lens. Charge and current neutralization are provided by a background gas. A detailed analysis of this system is presented here. The effects of additional magnetic fields are examined, including those produced by non-zero net currents, applied B effects near the diode, and diamagnetic effects in the solenoidal lens. Instabilities are analyzed including the filamentation instability, the two-stream instability (beam ions, plasma electrons), the plasma two-stream instability (plasma electrons, plasma ions), and the ion acoustic instability. Scattering in the foil and gas are shown to be negligible. Gas breakdown processes are analyzed in detail, including ion impact ionization, electron avalanching, and ohmic heating. Special diode requirements are examined, including voltage accuracy, energy spread, and aiming tolerances. The neutral gas and gas pressure are chosen to satisfy several constraints, one being that the net current must be small, and another being that the filamentation instability should be avoided. With the present choice of 1 Torr He, it is concluded that the complete achromatic lens system appears to be viable, simple, and efficient transport and focusing system for LMF

  11. 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.

  12. Equipment qualification research: test program and failure analysis of Class 1E solenoid valves

    This report documents the results of an equipment qualification research test program performed on ASCO solenoid valves. The valves were subjected to accelerated aging which included 50 Mrd of gamma radiation aging and accelerated thermal aging at 2680F (1310C). All valves performed satisfactorily during the seismic test. Of the seven valves exposed to the LOCA/MSLB simulation, only a metal-seated valve functioned properly throughout without leakage. At the conclusion of the post-LOCA functional testing, a failure analysis was undertaken to determine the failure mode(s) for each valve. The failure analysis included electrical testing of solenoid coils, controlled disassembly of valves, macro- and microscopic examination of internal parts, Shore A durometer testing of elastomeric components, and mass spectrometer analysis of several components. It was concluded that (1) the use of nitrogen to pressurize the valves during thermal aging severely inhibited the aging process since the majority of EPDM components were blanketed in nitrogen, and (2) operational cycling at the elevated thermal aging temperature may have produced stresses not representative of in-service use

  13. D0 Silicon Upgrade: Pipe Sizing for Solenoid / VLPC Cryogenic Systems

    Rucinski, Russ; Sakla, Steve; /Fermilab

    1995-02-20

    The addition of a solenoid magnet and VLPC detectors are two of a number of upgrades which will occur at the D-Zero detector in the near future. Both of these upgrades will require cryogenic services for their operation. The purpose of this engineering note is to document the pipe/tube size choices made for these cryogenic services. This was done by calculating the required flow rates to cool down the magnet and VLPC's over a reasonable length of time and to determine the required piping sizes for a given allowable pressure drop. The pressure drops for steady state conditions also are addressed. The cool down requirements drove the pipe size decision. The raw engineering calculations that were done for this project are included as an appendix to this note. The body of this document discusses the methods and results of the calculations. As a quick summary, Figures 1 and 2 show the size selections. Tables 1 and 2 give a more detailed size and description of each section of Solenoid and VLPC transfer line.

  14. 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

  15. 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.

  16. 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...

  17. Process for the fabrication of hollow core solenoidal microcoils in borosilicate glass

    We report the fabrication of solenoidal microcoils with hollow core embedded within two 100 µm thick borosilicate glass wafers. The main process steps are the reactive ion etching of borosilicate glass, anodic wafer bonding, copper metal organic chemical vapor deposition (Cu MOCVD) and electroless galvanization. Our motivation stems from the need for a reliable, precise fabrication method of microcoils for high-resolution magnetic resonance imaging (MRI). For reduced loss at high-frequency operation, glass, with a lower dielectric constant as compared to silicon, was chosen as a substrate material. Simultaneously, this offers MRI sample observation owing to its optical transparency. Further essential parameters for the coil design were the need for small coil dimensions, a high filling factor (region of interest within the coil occupied by the sample/overall coil volume), and low-loss electrical connectability to external devices. In an attempt to achieve those requirements, the reported process demonstrates the combination of front- and backside borosilicate glass RIE of small dimensional features (down to 10 µm wall thickness) with subsequent conformal metallization of the 3D solenoidal coil by means of Cu MOCV and electroless galvanization

  18. Constructing a 4-TESLA Large Thin Solenoid at the Limit of what can BE Safely Operated

    Hervé, A.

    The 4-tesla, 6 m free bore CMS solenoid has been successfully tested, operated and mapped at CERN during the autumn of 2006 in a surface hall and fully recommissioned in the underground experimental area in the autumn of 2008. The conceptual design started in 1990, the R&D studies in 1993, and the construction was approved in 1997. At the time the main parameters of this project were considered beyond what was thought possible as, in particular, the total stored magnetic energy reaches 2.6 GJ for a specific magnetic energy density exceeding 11 kJ/kg of cold mass. During this period, the international design and construction team had to make several important technical choices, particularly mechanical ones, to maximize the chances of reaching the nominal induction of 4 T. These design choices are explained and critically reviewed in the light of what is presently known to determine if better solutions would be possible today for constructing a new large high-field thin solenoid for a future detector magnet.

  19. Design and Implementation Solenoid Based Kicking Mechanism for Soccer Robot Applied in Robocup-MSL

    S.Hamidreza Mohades Kasaei

    2011-01-01

    Full Text Available RoboCup is an international competition to prompted robotics and related subject like: Artificial intelligence, Image processing, control, devise design and etc. One of the subjects in RoboCup competitions is Soccer. Naturally robotic soccer is an interactive and complex procedure. it might be so idealistic, but some consider a challenge with a real human football team in 2050 , as the final goal of robotic soccer. There are several classes in robotic football matches such as: Middle size, Small size, simulation and so on. One of the most essential parts of a soccer robot in Middle size and Small size classes in the kicking system, this system is in charge of kicking the ball upon the command issued by the processor of robot. Almost every team develops their own unique shooting device. There are three main approaches to design and implement the robot kicking system. In this paper we designed and developed multi power kicking system that enables loop and vary shooting power. To design a good solenoid and to obtain maximum velocity of ball some parameters like: inductance, response time, resistance, force, dimensions and core-material should be balanced carefully. We used a DC-DC converter (Boost regulator for getting different currents to have different power of shooting. We are going to review the advantages of all of those approaches. Next we are purposes a novel Solenoid-based kicking system which has already been successfully implemented in Adro RoboCup team.

  20. 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...

  1. Comparison of Accuracies for Image-based 1.5T and 3T MRI Using a Clinical Decision Support System Driven by a Support Vector Machine to Detect Seminal Vesicle Invasion of Prostate Cancer

    The purpose of this study is to develop image-based clinical decision support systems (CDSSs) using support vector machine models (SVMs) for the detection of seminal vesicle invasion (SVI) of prostate cancer and to compare the accuracies of 1.5T and 3.0T MR CDSSs. A total of 548 prostate cancer patients who underwent a prostatectomy and preoperative MR using 1.5T or 3.0T were enrolled in this study. Each 1.5T and 3.0T group was subdivided into the training group and test group, arbitrarily. Images were analyzed in consensus by two radiologists. CDSS was constructed with input data that has the appearance of a seminal vesicle, PSA level and age in each training group, and with the output data of the probability for SVI using SVMs. The accuracy of the output data were evaluated with data of each test group. After a histopathologic correlation, the sensitivity, specificity and accuracy for the detection of SVI were compared in both 1.5T and 3.0T. For the diagnosis of SVI, the specificity and the accuracy of the 3.0T model were all statistically superior to those of the 1.5T model (90.4% vs. 73.1%; 88.7% vs. 74.6%) (p<0.05). The image-based CDSS for the detection of SVI was successfully constructed using SVM. According to our CDSSs, the specificity and accuracy of 3.0T were superior to those of 1.5T

  2. FABRICATION OF A 3 m Ø x 5 m SUPERCONDUCTING SOLENOID FOR THE FERMILAB COLLIDER DETECTOR FACILITY

    Minemura, H.; Mori, S.; Yoshizaki, R.; Kondo, K.(Yamagata University, Yamagata, 992-8510, Japan); Fast, R; Kephart, R.; Wands, R.; Yamada, R.

    1984-01-01

    The 3mØ x 5m (1.5 Tesla) superconducting solenoid for the Fermilab Collider Detector Facility (CDF) is under construction in Japan. The coil consists of a single layer aluminum-stabilized monolithic NbTi/Cu superconductor fabricated with the EFT (extrusion with front tension) method. The forced flow cooling method of two-phase helium is used. In order to minimize the material thickness of the solenoid the coil is built without a permanent inner bobbin. The radial electromagnetic forces are su...

  3. Clinical indications for high-field 1.5 T intraoperative magnetic resonance imaging and neuro-navigation for neurosurgical procedures. Review of initial 100 cases

    Initial experiences are reviewed in an integrated operation theater equipped with an intraoperative high-field (1.5 T) magnetic resonance (MR) imager and neuro-navigation (BrainSUITE), to evaluate the indications and limitations. One hundred consecutive cases were treated, consisting of 38 gliomas, 49 other tumors, 11 cerebrovascular diseases, and 2 functional diseases. The feasibility and usefulness of the integrated theater were evaluated for individual diseases, focusing on whether intraoperative images (including diffusion tensor imaging) affected the surgical strategy. The extent of resection and outcomes in each histological category of brain tumors were examined. Intraoperative high-field MR imaging frequently affected or modified the surgical strategy in the glioma group (27/38 cases, 71.1%), but less in the other tumor group (13/49 cases, 26.5%). The surgical strategy was not modified in cerebrovascular or functional diseases, but the success of procedures and the absence of complications could be confirmed. In glioma surgery, subtotal or greater resection was achieved in 22 of the 31 patients (71%) excluding biopsies, and intraoperative images revealed tumor remnants resulting in the extension of resection in 21 of the 22 patients (95.4%), the highest rate of extension among all types of pathologies. The integrated neuro-navigation improved workflow. The best indication for intraoperative high-field MR imaging and integrated neuro-navigation is brain tumors, especially gliomas, and is supplementary in assuring quality in surgery for cerebrovascular or functional diseases. Immediate quality assurance is provided in several types of neurosurgical procedures. (author)

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

    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: ESVVCG = (56 ± 17) ml, EDVVCG = (151 ± 32) ml, LVMVCG = (97 ± 27) g, SVVCG = (94 ± 19) ml, EFVCG = (63 ± 5)% cf. ESVACT = (56 ± 18) ml, EDVACT = (147 ± 36) ml, LVMACT = (102 ± 29) g, SVACT = (91 ± 22) ml, EFACT = (62 ± 6)%; 3.0 T: ESVVCG = (55 ± 21) ml, EDVVCG = (151 ± 32) ml, LVMVCG = (101 ± 27) g, SVVCG = (96 ± 15) ml, EFVCG = (65 ± 7)% cf. ESVACT = (54 ± 20) ml, EDVACT = (146 ± 35) ml, LVMACT = (101 ± 30) g, SVACT = (92 ± 17) ml, EFACT = (64 ± 6)%). ACT's intrinsic insensitivity to interference from electromagnetic fields renders it suitable for clinical CMR. (orig.)

  5. Feasibility study of simultaneous physical examination and dynamic MR imaging of medial collateral ligament knee injuries in a 1.5-T large-bore magnet

    To determine the feasibility of evaluating medial knee joint laxity with dynamic magnetic resonance (MR) imaging and simultaneous physical joint examination in a large-bore 1.5-T system. The study included 10 patients (5 women, 5 men; mean age 35 years) with clinically diagnosed and categorized acute injuries of the medial collateral ligament (MCL). Intermittent valgus stress was applied separately to both the affected and the contralateral knee joint during dynamic MR imaging with a two-dimensional fast low-angle shot sequence. The width of the medial joint space and the opening angle between the femoral condyles and the tibial plateau were measured. Results obtained from dynamic MR imaging of the affected knee were compared with morphological MCL changes on static MRI, to kinematics of the contralateral side and to the clinical grading of MCL injuries. On clinical examination, all patients had grade 2 MCL injuries except one, who had a grade 1 lesion. Using morphological MRI criteria, 9 grade II and 1 grade III injuries were seen. Mean medial joint space width and opening angles of all affected knees were 2.8 mm and 2.7 respectively, compared with 1.7 mm and 2.1 on the contralateral side. The Wilcoxon signed rank test indicated that the differences in width (P = 0.005) and opening angle (P = 0.037) between the affected and contralateral knees were significant. Dynamic MR imaging and simultaneous physical joint examination is feasible. Our results suggest that this technique might enable the imaging documentation of medial ligamentous knee instability. (orig.)

  6. Feasibility study of simultaneous physical examination and dynamic MR imaging of medial collateral ligament knee injuries in a 1.5-T large-bore magnet

    Studler, Ueli [Mount Sinai Hospital and University Health Network, University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); University Hospital Basel, Department of Radiology, Basel (Switzerland); White, Lawrence M.; Deslandes, Melanie; Sussman, Marshall S. [Mount Sinai Hospital and University Health Network, University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); Geddes, Christopher; Theodoropoulos, John [Mount Sinai Hospital and University Health Network, University of Toronto, Division of Orthopedic Surgery, Toronto, ON (Canada)

    2011-03-15

    To determine the feasibility of evaluating medial knee joint laxity with dynamic magnetic resonance (MR) imaging and simultaneous physical joint examination in a large-bore 1.5-T system. The study included 10 patients (5 women, 5 men; mean age 35 years) with clinically diagnosed and categorized acute injuries of the medial collateral ligament (MCL). Intermittent valgus stress was applied separately to both the affected and the contralateral knee joint during dynamic MR imaging with a two-dimensional fast low-angle shot sequence. The width of the medial joint space and the opening angle between the femoral condyles and the tibial plateau were measured. Results obtained from dynamic MR imaging of the affected knee were compared with morphological MCL changes on static MRI, to kinematics of the contralateral side and to the clinical grading of MCL injuries. On clinical examination, all patients had grade 2 MCL injuries except one, who had a grade 1 lesion. Using morphological MRI criteria, 9 grade II and 1 grade III injuries were seen. Mean medial joint space width and opening angles of all affected knees were 2.8 mm and 2.7 respectively, compared with 1.7 mm and 2.1 on the contralateral side. The Wilcoxon signed rank test indicated that the differences in width (P = 0.005) and opening angle (P = 0.037) between the affected and contralateral knees were significant. Dynamic MR imaging and simultaneous physical joint examination is feasible. Our results suggest that this technique might enable the imaging documentation of medial ligamentous knee instability. (orig.)

  7. 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.

  8. Prostate MRI: diffusion-weighted imaging at 1.5T correlates better with prostatectomy Gleason grades than TRUS-guided biopsies in peripheral zone tumours

    To investigate the usefulness of Apparent Diffusion Coefficients (ADC) in predicting prostatectomy Gleason Grades (pGG) and Scores (GS), compared with ultrasound-guided biopsy Gleason Grades (bGG). Twenty-four patients with biopsy-proven prostate cancer were included in the study. Diffusion-weighted images were obtained using 1.5-T MR with a pelvic phased-array coil. Median ADC values (b0,500,1000 s/mm2) were measured at the most suspicious areas in the peripheral zone. The relationship between ADC values and pGG or GS was assessed using Pearson's coefficient. The relationship between bGG and pGG or GS was also evaluated. Receiver operating characteristic (ROC) curve analysis was performed to assess the performance of each method on a qualitative level. A significant negative correlation was found between mean ADCs of suspicious lesions and their pGG (r = -0.55; p 0.05) or GS (r = 0.048; p > 0.05). ROC analysis revealed a discriminatory performance of AUC = 0.82 for ADC and AUC = 0.46 for bGG in discerning low-grade from intermediate/high-grade lesions. The ADC values of suspicious areas in the peripheral zone perform better than bGG in the correlation with prostate cancer aggressiveness, although with considerable intra-subject heterogeneity. circle Prostate cancer aggressiveness is probably underestimated and undersampled by routine ultrasound-guided biopsies. circle Diffusion-weighted MR images show good linear correlation with prostate cancer aggressiveness. circle DWI information may be used to improve risk-assessment in prostate cancer. (orig.)

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

    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

  10. 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.)

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

    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 Fz (in millinewtons) was evaluated by determining the deflection angle β [American Society for Testing and Materials (ASTM standard test method)]. Magnetic-field-induced rotational force Frot was qualitatively determined using a five-point scale. β was found to be >45 in 13(15) devices at 1.5(3) T and translational force Fz exceeded gravitational force Fg on the particular object [Fz 10.17-261.4 mN (10.72-566.4 mN) at 1.5(3) T]. Fz was found to be up to 24.1(47.5)-fold higher than Fg at 1.5(3) T. Corresponding to this, Frot 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 rot was found to be ≥ +3 at both field strengths. For the remaining objects, β 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 Fz. The implications of these results for orthodontic patients undergoing MRI are discussed. (orig.)

  12. 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

    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

  13. 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.

  14. 1.5T MRI-SWI序列对桥脑出血性海绵状血管瘤的诊断价值%The Applicative Value of 1.5T MRI-SWI in the Diagnosis of Hemorrhagic Brainstem Cavernous Hemangioma

    陈颖

    2014-01-01

    Objective To discuss the applicative value of 1.5T MRI-SWI (Susceptibility weighted imaging) sequence in the diagnosis of hemorrhagic brainstem cavernous hemangioma (BCH).Methods Data of the SWI and common-MRI (c-MRI)、CT sequence in the 24 patients with hemorrhagic BCH were contrasted and analyzed.Results Compared with the c-MRI sequence and CT, the SWI sequence has a superior ability to discern the size、amount and the exact area of the hemorrhagic BCH cases.Conclusion 1.5T MRI-SWI is more sensitive than c-MRI and CT Sequence in the diagnosis of the hemorrhagic BCH, it can provide reliable assistance in the clinical cure .%目的:探讨1.5T磁共振磁敏感加权成像(SWI)对桥脑出血性海绵状血管瘤(BCH)的诊断及临床应用价值。方法回顾性分析24例桥脑出血性海绵状血管瘤患者的1.5T MRI SWI及常规MRI、CT图像;比较总结各组影像图像特点。结果各组图像病变检出率之间、同层病变出血平均面积组间差异有显著性(P<0.05)。SWI能够优于常规MRI、CT序列显示出血性BCH患者病灶的信号、数目及出血准确范围。结论磁共振磁敏感加权成像(SWI)对于发现病变、确定病变部位、病变大小具有较高的价值,可为临床早期治疗提供可靠的诊断依据。

  15. 34 GHz pulsed magnicon project

    A high efficiency, high power magnicon amplifier at 34.272 GHz has been designed as a radiation source to drive a multi-TeV electron-positron linear collider. Simulations predict a peak output power of 45 MW in a 1.5 microsecond pulse with an efficiency of 45% and a gain of 55 dB. The amplifier is a frequency tripler, or third harmonic amplifier, in that the output frequency of 34.272 GHz is three times the input drive frequency of 11.424 GHz. Thus the rotating TM110 modes in the drive cavity, 3 gain cavities and 2 penultimate cavities are resonant near 11.424 GHz; and the rotating TM310 mode in the output cavity is resonant at 34.272 GHz. A 500 kV, 215 A high area compression electron gun will provide an electron beam with a diameter less then 1 mm. A superconducting solenoid magnet will provide a magnetic field of 13 kG in the deflection system and 23 kG in the output cavity. Simulation results for the operation of the entire magnicon amplifier (gun, magnetic system, RF system and collector) will be given, and the status described of critical hardware components

  16. 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...

  17. {sup 31}P-MR spectroscopy of all regions of the human heart at 1.5 T with acquisition-weighted chemical shift imaging; P-MR-Spektroskopie aller Wandabschnitte des menschlichen Herzens bei 1,5 T mit akquisitionsgewichteter Chemical-shift-Bildgebung

    Koestler, H.; Beer, M.; Buchner, S.; Sandstede, J.; Pabst, T.; Kenn, W.; Hahn, D. [Wuerzburg Univ. (Germany). Abt. fuer Roentgendiagnostik; Landschuetz, W.; Kienlin, M. von [Wuerzburg Univ. (Germany). Physikalisches Inst.; Neubauer, S. [Dept. of Cardiovascular Medicine, John Radcliffe Hospital, Oxford (United Kingdom)

    2001-12-01

    Aim: Aim of this study was to show whether or not acquisition-weighted chemical shift imaging (AW-CSI) allows the determination of PCr and ATP in the lateral and posterior wall of the human heart at 1.5 T. Methods: 12 healthy volunteers were examined using a conventional chemical shift imaging (CSI) and an AW-CSI. The sequences differed only in the number of repetitions for each point in k space. A hanning function was used as filter function leading to 7 repetitions in the center of the k space and 0 in the corners. Thus, AW-CSI had the same resolution as the CSI sequence. The results for both sequences were analyzed using identically positioned voxels in the septal, anterior, lateral and posterior wall. Results: The determined averaged AW-CSI signal to noise ratios were higher for PCr by a factor of 1.3 and for ATP by 1.4 than those of CSI. The PCr/ATP ratios were higher by a factor of 1.2 - 1.3 and showed a smaller standard deviation in all locations for AW-CSI. The mean PCr/ATP ratios determined by AW-CSI of septal, lateral and posterior wall were almost identical (1.72 - 1.76), while it was higher in the anterior wall (1.9). Conclusions: The reduced contamination in AW-CSI improves the signal to noise ratio and the determination of the PCr/ATP ratio in cardiac {sup 31}P spectroscopy compared to CSI with the same resolution. The results in volunteers indicate that AW-CSI renders {sup 31}P spectroscopy of the lateral and posterior wall of the human heart feasible for patient studies at 1.5 T. (orig.) [German] Ziel: Ziel der Arbeit war es zu untersuchen, ob die akquisitionsgewichtete Chemical-shift-Bildgebung (AW-CSI) die Bestimmung von PCr und ATP in der Seiten- und Hinterwand des menschlichen Herzens an einem klinischen 1,5 T MR-Tomographen erlaubt. Methoden: 12 gesunde Probanden wurden jeweils mit einer chemical shift imaging (CSI) und einer AW-CSI-Sequenz untersucht. Die Sequenzen unterschieden sich lediglich in der Anzahl der Wiederholungen der einzelnen Phasenkodierschritte. Als Wichtungsfunktion des AW-CSI wurde eine Hanningfunktion verwendet, die zu 7 Mittelungen in der Mitte und 0 in den Ecken des k-Raums fuehrte und die gleiche Aufloesung wie das CSI ergab. Die Auswertung erfolgte in jewells identisch positionierten Voxeln in Septum, Vorder-, Seiten- und Hinterwand. Ergebnisse: Die Signal-zu-Rausch-Verhaeltnisse waren bei AW-CSI fuer PCr um 1,3 und fuer ATP um 1,4 hoeher. Fuer AW-CSI waren die PCr/ATP-Verhaeltnisse um einen Faktor 1,2 - 1,3 hoeher und zeigten in allen untersuchten Regionen eine kleinere Standardabweichung. Das mittlere PCr/ATP-Verhaeltnis der AW-CSI-Sequenz war in Septum, Seiten- und Hinterwand praktisch identisch (1,72 - 1,76), waehrend in der Vorderwand ein hoeherer Wert (1,9) bestimmt wurde. Schlussfolgerungen: Die deutlich reduzierte Kontamination aus Nachbarvoxeln fuehrt bei AW-CSI zu einer Verbesserung des Signal-zu-Rausch-Verhaeltnisses und zu einer genaueren Bestimmung des PCr/ATP-Verhaeltnisses im Vergleich zu CSI mit gleicher Aufloesung. AW-CSI ermoeglicht so die {sup 31}P-Spektroskopie von Seiten- und Hinterwand des menschlichen Herzens bei 1,5 T. (orig.)

  18. 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

  19. Myocardial T2* mapping free of distortion using susceptibility-weighted fast spin-echo imaging: a feasibility study at 1.5 T and 3.0 T.

    Heinrichs, Uwe; Utting, Jane F; Frauenrath, Tobias; Hezel, Fabian; Krombach, Gabriele A; Hodenius, Michael A J; Kozerke, Sebastian; Niendorf, Thoralf

    2009-09-01

    This study demonstrates the feasibility of applying free-breathing, cardiac-gated, susceptibility-weighted fast spin-echo imaging together with black blood preparation and navigator-gated respiratory motion compensation for anatomically accurate T2* mapping of the heart. First, T2* maps are presented for oil phantoms without and with respiratory motion emulation T2* = (22.1 +/- 1.7) ms at 1.5 T and T2* = (22.65 +/- 0.89) ms at 3.0 T). T2* relaxometry of a ferrofluid revealed relaxivities of R2* = (477.9 +/- 17) mM(-1)s(-1) and R2* = (449.6 +/- 13) mM(-1)s(-1) for UFLARE and multiecho gradient-echo imaging at 1.5 T. For inferoseptal myocardial regions mean T2* values of 29.9 +/- 6.6 ms (1.5 T) and 22.3 +/- 4.8 ms (3.0 T) were estimated. For posterior myocardial areas close to the vena cava T2*-values of 24.0 +/- 6.4 ms (1.5 T) and 15.4 +/- 1.8 ms (3.0 T) were observed. The merits and limitations of the proposed approach are discussed and its implications for cardiac and vascular T2*-mapping are considered. PMID:19526490

  20. Comparison of Cartesian and Non-Cartesian Real-Time MRI Sequences at 1.5T to Assess Velar Motion and Velopharyngeal Closure during Speech

    Freitas, Andreia C.; Wylezinska, Marzena; Birch, Malcolm J.; Petersen, Steffen E.; Miquel, Marc E.

    2016-01-01

    Dynamic imaging of the vocal tract using real-time MRI has been an active and growing area of research, having demonstrated great potential to become routinely performed in the clinical evaluation of speech and swallowing disorders. Although many technical advances have been made in regards to acquisition and reconstruction methodologies, there is still no consensus in best practice protocols. This study aims to compare Cartesian and non-Cartesian real-time MRI sequences, regarding image quality and temporal resolution trade-off, for dynamic speech imaging. Five subjects were imaged at 1.5T, while performing normal phonation, in order to assess velar motion and velopharyngeal closure. Data was acquired using both Cartesian and non-Cartesian (spiral and radial) real-time sequences at five different spatial-temporal resolution sets, between 10 fps (1.7×1.7×10 mm3) and 25 fps (1.5×1.5×10 mm3). Only standard scanning resources provided by the MRI scanner manufacturer were used to ensure easy applicability to clinical evaluation and reproducibility. Data sets were evaluated by comparing measurements of the velar structure, dynamic contrast-to-noise ratio and image quality visual scoring. Results showed that for all proposed sequences, FLASH spiral acquisitions provided higher contrast-to-noise ratio, up to a 170.34% increase at 20 fps, than equivalent bSSFP Cartesian acquisitions for the same spatial-temporal resolution. At higher frame rates (22 and 25 fps), spiral protocols were optimal and provided higher CNR and visual scoring than equivalent radial protocols. Comparison of dynamic imaging at 10 and 22 fps for radial and spiral acquisitions revealed no significant difference in CNR performance, thus indicating that temporal resolution can be doubled without compromising spatial resolution (1.9×1.9 mm2) or CNR. In summary, this study suggests that the use of FLASH spiral protocols should be preferred over bSSFP Cartesian for the dynamic imaging of velopharyngeal closure, as it allows for an improvement in CNR and overall image quality without compromising spatial-temporal resolution. PMID:27073905

  1. Comparison of Cartesian and Non-Cartesian Real-Time MRI Sequences at 1.5T to Assess Velar Motion and Velopharyngeal Closure during Speech.

    Freitas, Andreia C; Wylezinska, Marzena; Birch, Malcolm J; Petersen, Steffen E; Miquel, Marc E

    2016-01-01

    Dynamic imaging of the vocal tract using real-time MRI has been an active and growing area of research, having demonstrated great potential to become routinely performed in the clinical evaluation of speech and swallowing disorders. Although many technical advances have been made in regards to acquisition and reconstruction methodologies, there is still no consensus in best practice protocols. This study aims to compare Cartesian and non-Cartesian real-time MRI sequences, regarding image quality and temporal resolution trade-off, for dynamic speech imaging. Five subjects were imaged at 1.5T, while performing normal phonation, in order to assess velar motion and velopharyngeal closure. Data was acquired using both Cartesian and non-Cartesian (spiral and radial) real-time sequences at five different spatial-temporal resolution sets, between 10 fps (1.7×1.7×10 mm3) and 25 fps (1.5×1.5×10 mm3). Only standard scanning resources provided by the MRI scanner manufacturer were used to ensure easy applicability to clinical evaluation and reproducibility. Data sets were evaluated by comparing measurements of the velar structure, dynamic contrast-to-noise ratio and image quality visual scoring. Results showed that for all proposed sequences, FLASH spiral acquisitions provided higher contrast-to-noise ratio, up to a 170.34% increase at 20 fps, than equivalent bSSFP Cartesian acquisitions for the same spatial-temporal resolution. At higher frame rates (22 and 25 fps), spiral protocols were optimal and provided higher CNR and visual scoring than equivalent radial protocols. Comparison of dynamic imaging at 10 and 22 fps for radial and spiral acquisitions revealed no significant difference in CNR performance, thus indicating that temporal resolution can be doubled without compromising spatial resolution (1.9×1.9 mm2) or CNR. In summary, this study suggests that the use of FLASH spiral protocols should be preferred over bSSFP Cartesian for the dynamic imaging of velopharyngeal closure, as it allows for an improvement in CNR and overall image quality without compromising spatial-temporal resolution. PMID:27073905

  2. 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.)

  3. Development of large high current density superconducting solenoid magnets for use in high energy physics experiments. [Thesis

    Green, M.A.

    1977-05-01

    The development of a unique type of large superconducting solenoid magnet, characterized by very high current density windings and a two-phase helium tubular cooling system is described. The development of the magnet's conceptual design and the construction of two test solenoids are described. The successful test of the superconducting coil and its tubular cooling refrigeration system is presented. The safety, environmental and economic impacts of the test program on future developments in high energy physics are shown. Large solid angle particle detectors for colliding beam physics will analyze both charged and neutral particles. In many cases, these detectors will require neutral particles, such as gamma rays, to pass through the magnet coil with minimum interaction. The magnet coils must be as thin as possible. The use of superconducting windings allows one to minimize radiation thickness, while at the same time maximizing charged particle momentum resolution and saving substantial quantities of electrical energy. The results of the experimental measurements show that large high current density solenoid magnets can be made to operate at high stored energies. The superconducting magnet development described has a positive safety and environmental impact. The use of large high current density thin superconducting solenoids has been proposed in two high energy physics experiments to be conducted at the Stanford Linear Accelerator Center and Cornell University as a result of the successful experiments described.

  4. Development of high-strength and high-RRR aluminum-stabilized superconductor for the ATLAS thin solenoid

    Wada, K; Sakamoto, H; Shimada, T; Nagasu, Y; Inoue, I H; Tsunoda, K; Endo, S; Yamamoto, A; Makida, Y; Tanaka, K; Doi, Y; Kondo, T

    2000-01-01

    The ATLAS central solenoid magnet is being constructed to provide a magnetic field of 2 Tesla in the central tracking part of the ATLAS detector at the LHC. Since the solenoid coil is placed in front of the liquid-argon electromagnetic calorimeter, the solenoid coil must be as thin (and transparent) as possible. The high-strength and high- RRR aluminum-stabilized superconductor is a key technology for the solenoid to be thinnest while keeping its stability. This has been developed with an alloy of 0.1 wt% nickel addition to 5N pure aluminum and with the subsequent mechanical cold working of 21% in area reduction. A yield strength of 110 MPa at 4.2 K has been realized keeping a residual resistivity ratio (RRR) of 590, after a heat treatment corresponding to coil curing at 130 degrees C for 15 hrs. This paper describes the optimization of the fabrication process and characteristics of the developed conductor. (8 refs).

  5. C.A.P. plasma physics summer school, Banff, June 1975. I. Experiments on laser-heated solenoids and pinches

    A review is given of experimental progress on the use of long wavelength lasers (CO2 or CO) to heat long, magnetically confined plasma columns to thermonuclear temperatures. Theoretical studies of the feasibility of the concept for controlled fusion power are reviewed. The laser-heated solenoid concept is reviewed in particular

  6. 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...

  7. Investigation of the effects of aging and hazardous environments on the performance of solenoid operated valves

    An aging and qualification research program was conducted at Franklin Research Center (FRC) on solenoid operated valves (SOVs) to investigate their performance under normal and accident conditions in a nuclear power generating station. The investigation was a follow-on of earlier work reported in a NUREG and several papers. The major segments of the aging and accident test sequence were: thermal and operational aging, gamma irradiation to the equivalent of an accident dose, and main-steam-line-break/loss-of-coolant accident simulation. The effects of the use of air versus nitrogen as the process medium during accelerated aging and the effects of natural versus accelerated aging were investigated. The program was initiated with enough specimens so that one could be removed for functional testing, disassembly, and measurement of component properties after each major segment of the program

  8. Comparison of naturally and artificially aged solenoid valves in accident simulations

    A qualification research program conducted on naturally and artificially aged solenoid valves revealed no significant differences in performance during seismic tests, but some differences during main-steam-line-break/loss-of-coolant-accident (MSLB/LOCA) simulation. Although the naturally aged valves were subjected to less severe aging than the artificially aged valves, they failed earlier than the artificially aged valves in the MSLB/LOCA test. Only a valve with metal seats performed satisfactorily throughout the program. All other valves tested experiences failure or diminished functional capability as a consequence of degradation of the EPDM components (seals, seats, diaphragms). Degradation manifested itself in the form of severe compressive set, embrittlement, and adherence of tacky material to bounding metal parts. There were also two coil failures. This paper analyzes the causes of degradation and recommends ways of improving the qualification method. 3 figs.

  9. Qualification research study of naturally and artificially aged solenoid valves in accident simulations

    A qualification research program conducted on naturally and artificially aged solenoid valves revealed no significant differences in performance during seismic tests, but some differences during main-steam-line-break/loss-of-coolantaccident (MSLB/LOCA) simulation. Although the naturally aged valves were subjected to less severe aging than the artificially aged valves, they failed earlier than the artificially aged valves in the MSLB/LOCA test. Only a valve with metal seats performed satisfactorily throughout the program. All other valves tested experienced failure or diminished functional capability as a consequence of degradation of the EPDM components (seals, seats, diaphragms). Degradation manifested itself in the form of severe compression set, embrittlement, and adherence of tacky material to bounding metal parts. There were also two coil failures. This paper analyzes the causes of degradation and reviews the implications of the program with respect to qualification methodology and the adequacy of the valves for safety-related service

  10. 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/

  11. Endloss from a slender high beta plasma column contained in a linear solenoid

    A model is presented to simulate endloss from a high beta plasma contained laterally in a straight solenoid. For slender plasma columns, the plasma lifetime depends on both the acoustic transit time (time for a sound wave to traverse one-half of the plasma length), and the characteristic radial diffusion time (diffusion of plasma across the magnetic field). In the limit of strong diffusion (which occurs for narrow high beta plasma columns), the plasma lifetime equals the hybrid lifetime which is proportional to the geometric mean of the acoustic and diffusion times. This predicted behavior stands in marked contrast with conventional endloss theories which have confinement time proportional to acoustic time alone. It is also shown that the endloss process may be accelerated considerably if the ratio of plasma radius to magnet radius is not small, due to inverse mirroring effects in the streaming plasma

  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. The silicon sensors for the Inner Tracker of the Compact Muon Solenoid experiment

    Krammer, Manfred

    2004-01-01

    The Inner Tracker of the Compact Muon Solenoid (CMS) experiment, at present under construction, will consist of more than 24000 silicon strip sensors arranged in 10 central concentric layers and 2 multiplied by 9 discs at both ends. The total sensitive silicon area will be about 200 m**2. The silicon sensors are produced in various thicknesses and geometries. Each sensor has 512 or 768 implanted strips which will allow the measurement of the position of traversing high-energy charged particles. This paper gives a short overview of the CMS tracker system. Subsequently, the design of the silicon sensors is explained with special emphasis on the radiation hardness and on the high-voltage stability of the sensors. Two companies share the production of these sensors. The quality of the sensors is extensively checked by several laboratories associated with CMS. Important electrical parameters are measured on the sensors themselves. In addition, dedicated test structures designed by CMS allow the monitoring of many ...

  14. 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.

  15. Assessment of nonintrusive methods for monitoring the operational readiness of solenoid-operated valves

    Solenoid-operated valves (SOVs) are being studied at Oak Ridge National Laboratory as part of the USNRC Nuclear Plant Aging Research (NPAR) Program. The primary objective of the study is to identify and recommend methods for inspection, surveillance, and maintenance of SOVs that can ensure their operational readiness-- that is, their ability to perform required safety functions under all anticipated operating conditions. An earlier (Phase I) study described SOV failure modes and causes and identified measurable parameters that might be used to monitor the various degradations that lead to functional failure. The present (Phase II) study focuses on devising and then demonstrating the effectiveness of techniques and/or equipment with which to measure the previously identified performance parameters and thus detect and trend the progress of any degradation. Several nonintrusive techniques are currently under investigation. Recent experimental results which demonstrate the feasibility and practicality of the techniques being studied are presented. 4 refs., 6 figs., 2 tabs

  16. A modular straw drift tube tracking system for the Solenoidal Detector Collaboration experiment. Pt. I. Design

    For pt.II see ibid., p.372-84, 1996. We have developed the baseline design for a straw drift tube tracking system for the Solenoidal Detector Collaboration (SDC) detector. The system was designed to operate in the high-rate environment of a high luminosity hadron collider. We present an overview of the tracking system and the requirements it was expected to fulfill. We describe the construction and properties of the straw drift tubes. We discuss the design of the carbon-fiber foam-laminate shell, which supported the wire tension and held the straws in alignment. We also present descriptions of the designs of the front-end and digitization electronics as well as the electronics associated with the level 1 track trigger. (orig.)

  17. D-zero rototrack: first stage of D-zero 2 Tesla solenoid field mapping device

    A simple and portable field mapping device was developed at Fermilab and successfully used to test the D0 2 Tesla solenoid at Toshiba Works in Japan. A description of the mechanical structure, electric driving and control system, and software of the field mapping device is given. Four Hall probe elements of Group3 Digital Gaussmeters are mounted on the radial extension arm of a carriage, which is mounted on a central rotating beam. The system gives two dimensional motions (axial and rotational) to the Hall probes. To make the system compact and portable, we used a laptop computer with PCMCIA cards. For the control system we used commercially available software LabVIEW and Motion Toolbox, and for the data analysis we used Microsoft Excel

  18. 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...

  19. 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.

  20. Realisation of a β spectrometer solenoidal and a double β spectrometer at coincidence

    The two spectrometers have been achieved to tackle numerous problems of nuclear spectrometry. They possess different fields of application that complete themselves. The solenoidal spectrometer permits the determination of the energy limits of β spectra and of their shape; it also permits the determination of the coefficients of internal conversion and reports αK / αL and it is especially efficient for the accurate energy levels of the γ rays by photoelectric effect. The double coincidence spectrometer has been conceived to get a good efficiency in coincidence: indeed, the sum of the solid angles used for the β and γ emission is rather little lower to 4π steradians. To get this efficiency, one should have sacrificed a little the resolution that is lower to the one obtained with the solenoidal spectrometer for a same brightness. Each of the elements of the double spectrometer can also be adapted to the study of angular correlations βγ and e-γ. In this use, it is superior to the thin magnetic lens used up to here. The double spectrometer also permits the survey of the coincidences e-e-, e-β of a equivalent way to a double lens; it can also be consider some adaptation for the survey of the angular correlations e-e-, e-β. Finally, we applied the methods by simple spectrometry and by coincidence spectrometry, to the study of the radiances of the following radioelements: 76As (26 h), 122Sb (2,8 j), 124Sb (60 j), 125Sb (2,7 years). (M.B.)

  1. Silicon subsystem mechanical engineering closeout report for the Solenoidal Detector Collaboration

    Hanlon, J.; Christensen, R.W.; Hayman, G.; Jones, D.C.; Ross, R.; Wilds, W.; Yeamans, S.; Ziock, H.J.

    1995-02-01

    The authors group at Los Alamos National Laboratory was responsible for the mechanical engineering of the silicon tracking system of the Solenoidal Detector Collaboration (SDC) experiment of the Superconducting Super Collider (SSC) project. The responsibility included the overall design of the system from the mechanical point of view, development and integration of the cooling system, which was required to remove the heat generated by the front-end electronics, assembly of the system to extremely tight tolerances, and verification that the construction and operational stability and alignment tolerances would be met. A detailed description of the concepts they developed and the work they performed can be found in a report titled ``Silicon Subsystem Mechanical Engineering Work for the Solenoidal Detector Collaboration`` which they submitted to the SSC Laboratory. In addition to the mechanical engineering work, they also performed activation, background, and shielding studies for the SSC program. Much of the work they performed was potentially useful for other future high energy physics (HEP) projects. This report describes the closeout work that was performed for the Los Alamos SDC project. Four major tasks were identified for completion: (1) integration of the semi-automated assembly station being developed and construction of a precision part to demonstrate solutions to important general assembly problems (the station was designed to build precision silicon tracker subassemblies); (2) build a state-of-the-art TV holography (TVH) system to use for detector assembly stability tests; (3) design, build, and test a water based cooling system for a full silicon shell prototype; and (4) complete and document the activation, background, and shielding studies, which is covered in a separate report.

  2. Self-consistent analysis of alpha-particle heating of a fast-solenoid plasma

    A numerical technique has been developed to analyse the dynamics of a linear, magnetically confined plasma column and its associated fusion-produced alpha-particles in a self consistent manner. The thermonuclear background plasma is considered as a radially non-uniform, axially symmetric magnetofluid in pressure equilibrium with the surrounding axial magnetic field. A multi-group technique is utilized to examine the alphas as a collection of particles distributed among a continuous spectrum of confined orbits. The technique is shown to be an effective one for observing the interaction between super-thermal particles with large orbit sizes and a stable plasma of comparable size. The use of a distribution function in an adiabatic-invariant representation results in an enormous increase in the time scale which can be treated. This enables analysis of the entire duty cycle of a laser solenoid plasma in reasonable computation times. An analysis of a fast solenoid plasma is described, where the initial plasma radius and temperature are varied parametrically. A plasma column of radius 7mm, temperature 6keV, and β=0.95 will reach an ion temperature of 10keV, corresponding to a fusion energy gain of 8, after 3ms. A range of maximum gain occurs for initial temperatures of 5 to 7keV, with larger radius plasmas more favoured by the cooler limits. The effect of increasing the alpha-particle-electron energy transfer rate by a moderate amount to account for anomalous effects is to increase the plasma temperature at longer times, as long as this energy transfer is well-coupled to the electron-ion energy transfer. Increasing the rate at which plasma transport processes occur (''anomalous transport'') always results in lower fusion yield, because of rapid plasma diffusion. (author)

  3. Silicon subsystem mechanical engineering closeout report for the Solenoidal Detector Collaboration

    The authors group at Los Alamos National Laboratory was responsible for the mechanical engineering of the silicon tracking system of the Solenoidal Detector Collaboration (SDC) experiment of the Superconducting Super Collider (SSC) project. The responsibility included the overall design of the system from the mechanical point of view, development and integration of the cooling system, which was required to remove the heat generated by the front-end electronics, assembly of the system to extremely tight tolerances, and verification that the construction and operational stability and alignment tolerances would be met. A detailed description of the concepts they developed and the work they performed can be found in a report titled ''Silicon Subsystem Mechanical Engineering Work for the Solenoidal Detector Collaboration'' which they submitted to the SSC Laboratory. In addition to the mechanical engineering work, they also performed activation, background, and shielding studies for the SSC program. Much of the work they performed was potentially useful for other future high energy physics (HEP) projects. This report describes the closeout work that was performed for the Los Alamos SDC project. Four major tasks were identified for completion: (1) integration of the semi-automated assembly station being developed and construction of a precision part to demonstrate solutions to important general assembly problems (the station was designed to build precision silicon tracker subassemblies); (2) build a state-of-the-art TV holography (TVH) system to use for detector assembly stability tests; (3) design, build, and test a water based cooling system for a full silicon shell prototype; and (4) complete and document the activation, background, and shielding studies, which is covered in a separate report

  4. 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.

  5. 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).

  6. Low-induction pulse current generator with a volume bus arrangement

    Pulse current generator (PC6) with 38 kj stored energy designed for up to 50 kV charging voltage used to obtain magnetic fields within megagauss range, is described. Space (volume) bus arrangement of its modules is used to reduce eigen inductance of PC6. Current is commutated by solid-body spark gaps. Under 3uH inductive load PC6 provides for formation of up to 2.25 MA current pulse with 3.3x1012 A/s pulse rise time. Technique to determine low inductances as applied to PC6 elements is described. The described PC6 is used for experiments on generation of super-strong pulse magnetic fields in single-loop solenoid with volume occupied by magnetic field, 5-7 mm. Magnetic field with up to 350 T induction amplitude is obtained in these experiments

  7. Construction and testing of the two meter diameter TPC thin superconducting solenoid

    High energy colliding beam physics often requires large detectors which contain large volumes of magnetic field. The TPC (Time Projection Chamber) experiment at PEP will use a 1.5T magnetic field within a cylindrical volume which is 2.04m in diameter bounded by iron poles which are separated by a gap of 3.25m. The TPC magnet, built in 1979 by the Lawrence Berkeley Laboratory (LBL), is the largest high current density superconducting magnet built to date. It is designed to operate at a current density of 7 x 108Am-2 and a stored energy of 11MJ, and it is protected by shorted secondary windings during a quench. The paper describes the basic parameters of the TPC magnet and the results of the first subassembly tests at LBL

  8. Pulse radiolysis

    This supplement to two bibliographies published in 1970 and 1972 lists 734 references to the literature of pulse radiolysis, arranged under eight broad subject headings. The references were compiled by searching Biological Abstracts, Chemical Abstracts, Nuclear Science Abstracts and the Weekly List of Papers in Radiation Chemistry issued by the Radiation Chemistry Data Center of Notre Dame University. Full bibliographic data is given for papers published in the period 1971 to 1974. A personal author index listing more than 600 authors and a similar number of co-authors is included

  9. Hole density of ferromagnetic semiconductor (Ga, Mn)As studied via pulsed high magnetic field

    Transport measurements of as-grown and annealed (Ga,Mn)As samples were conducted under pulsed high magnetic field up to 40T. Assuming that the magnetization follows modified Brillouin function, we obtained the hole densities of the (Ga,Mn)As samples at various temperatures, which generally increase with temperature and become two times larger after annealing process. The hole density determined by electrical transport measurement at low magnetic field up to 1.5T is found to be underestimated.

  10. Pulse pile-up. I: Short pulses

    The search for rare large pulses against an intense background of smaller ones involves consideration of pulse pile-up. Approximate methods are presented, based on ruin theory, by which the probability of such pile-up may be estimated for pulses of arbitrary form and of arbitrary pulse-height distribution. These methods are checked against cases for which exact solutions are available. The present paper is concerned chiefly with short pulses of finite total duration. (Author) (5 refs., 24 figs.)

  11. Pulse stretcher ring facilities at Bates

    An upgrade of the MIT-Bates Linear Accelerator Center has been developed which would provide high duty factor (CW) electron beams, up to 1 GeV, for nuclear research. The central element in the proposal is a Pulse Stretcher Ring (PSR) which when fed by the existing accelerator/recirculator system would produce extracted beams with a duty factor approx. 85% and an output emittance approx. 0.01π mm-mr. Other proposed facilities include an energy compression system, recirculator extension and a solenoid system for producing longitudinally polarized CW beams. The proposal includes an experimental hall intersecting the ring which will provide a unique opportunity to develop a pilot program of electronuclear studies with polarized targets. The developing technology for sufficiently high density targets looks very promising and will be further encouraged by access to such dedicated facilities. We discuss the facility; including a description of the accelerator/recirculator as well as the research equipment. The present physics program is described in the context of the experimental equipment. An ongoing program of facility improvements to develop other essential capabilities such as longitudinally polarized electron beams is also discussed. The proposed new facilities which are essential for achieving CW operation are described. Included is a discussion of the operation of the pulse stretcher ring as well as a description of the internal target hall. Costs and a schedule for completing this project are summarized. 10 references, 8 figures

  12. Detection of hepatic metastases by superparamagnetic iron oxide-enhanced MR imaging: prospective comparison between 1.5-T and 3.0-T images in the same patients

    To prospectively compare the diagnostic performance of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging at 3.0 T and 1.5 T for detection of hepatic metastases. A total of 28 patients (18 men, 10 women; mean age, 61 years) with 80 hepatic metastases were prospectively examined by SPIO-enhanced MR imaging at 3.0 T and 1.5 T. T1-weighted gradient-recalled-echo (GRE) images, T2*-weighted GRE images and T2-weighted fast spin-echo (SE) images were acquired. The tumour-to-liver contrast-to-noise ratio (CNR) of the lesions was calculated. Three observers independently reviewed each image. Image artefacts and overall image quality were analysed, sensitivity and positive predictive value for the detection of hepatic metastases were calculated, and diagnostic accuracy using the receiver-operating characteristics (ROC) method was evaluated. The tumour-to-liver CNRs were significantly higher at 3.0 T. Chemical shift and motion artefact were more severe, and overall image quality was worse on T2-weighted fast SE images at 3.0 T. Overall image quality of the two systems was similar on T1-weighted GRE images and T2*-weighted GRE images. Sensitivity and area under the ROC curve for the 3.0-T image sets were significantly higher. SPIO-enhanced MR imaging at 3.0 T provided better diagnostic performance for detection of hepatic metastases than 1.5 T. (orig.)

  13. 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

  14. Detection of hepatic metastases by superparamagnetic iron oxide-enhanced MR imaging: prospective comparison between 1.5-T and 3.0-T images in the same patients

    Sofue, Keitaro; Miyake, Mototaka; Sakurada, Aine; Arai, Yasuaki [National Cancer Center, Department of Radiology, Tokyo (Japan); Tsurusaki, Masakatsu [National Cancer Center, Department of Radiology, Tokyo (Japan); National Cancer Center Hospital, Division of Diagnostic Radiology, Chuo-ku, Tokyo (Japan); Sugimura, Kazuro [Kobe University, Department of Radiology, Graduate School of Medicine, Kobe (Japan)

    2010-09-15

    To prospectively compare the diagnostic performance of superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging at 3.0 T and 1.5 T for detection of hepatic metastases. A total of 28 patients (18 men, 10 women; mean age, 61 years) with 80 hepatic metastases were prospectively examined by SPIO-enhanced MR imaging at 3.0 T and 1.5 T. T1-weighted gradient-recalled-echo (GRE) images, T2*-weighted GRE images and T2-weighted fast spin-echo (SE) images were acquired. The tumour-to-liver contrast-to-noise ratio (CNR) of the lesions was calculated. Three observers independently reviewed each image. Image artefacts and overall image quality were analysed, sensitivity and positive predictive value for the detection of hepatic metastases were calculated, and diagnostic accuracy using the receiver-operating characteristics (ROC) method was evaluated. The tumour-to-liver CNRs were significantly higher at 3.0 T. Chemical shift and motion artefact were more severe, and overall image quality was worse on T2-weighted fast SE images at 3.0 T. Overall image quality of the two systems was similar on T1-weighted GRE images and T2*-weighted GRE images. Sensitivity and area under the ROC curve for the 3.0-T image sets were significantly higher. SPIO-enhanced MR imaging at 3.0 T provided better diagnostic performance for detection of hepatic metastases than 1.5 T. (orig.)

  15. Performance in muon identification and muon momentum measurement by the compact muon solenoid experiment at the LHC

    The Compact Muon Solenoid (CMS) experiment at the LHC is based on a 4T superconducting solenoid. The muon momentum is measured in three ways - bending angle measurement immediately after the coil, sagitta measurement in the return yoke, and sagitta measurement in the inner tracker. The first two measurements are performed with the muon detector alone, independent of the inner tracker (stand alone measurement). The best resolution is obtained when all three methods are combined. The simulated performance for both stand alone and best resolutions will be presented for momenta from a few GeV to a few TeV in rapidity range from 0 to 2.4. The redundency of the measurement makes the system robust against background. Effect of the background or muon identification will be presented. Benchmark physics processes will be used to illustrate the performance of the muon system

  16. 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.; Mygind, Jesper

    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 the ge...... inserting a thin sheet of high-permeability material, and the result is numerically tested....

  17. Endometriose pélvica: comparação entre imagens por ressonância magnética de baixo campo (0,2 T e alto campo (1,5 T Pelvic endometriosis: a comparison between low-field (0.2 T and high-field (1.5 T magnetic resonance imaging

    Karine Minaif

    2008-12-01

    Full Text Available OBJETIVO: Comparar a ressonância de baixo campo (0,2 T com a de alto campo (1,5 T na avaliação da endometriose pélvica e adenomiose. MATERIAIS E MÉTODOS: Foram estudadas, prospectivamente, 27 pacientes do sexo feminino com suspeita clínica de endometriose, realizando-se exames de ressonância magnética de alto campo e baixo campo. Um mesmo radiologista realizou a leitura dos exames, iniciando pelo baixo campo, seguido pelo alto campo, usando como padrão-ouro o alto campo. RESULTADOS: Das 27 pacientes estudadas, 18 (66,7% apresentaram alguma lesão indicativa de endometriose nos exames realizados no alto campo. Foram corretamente diagnosticados pelo baixo campo 14 destas pacientes. Endometriomas, lesões tubárias e focos de endometriose maiores do que 7 mm identificados pelo alto campo foram também identificados no baixo campo, com acurácia, sensibilidade e especificidade de 100%. Das nove pacientes com adenomiose caracterizadas pelo alto campo, oito foram corretamente identificadas pelo baixo campo, com acurácia, sensibilidade e especificidade de 88,9%. CONCLUSÃO: A ressonância de baixo campo apresentou baixa sensibilidade na detecção de pequenos focos de endometriose, alta sensibilidade na detecção de endometriomas e focos de endometriose grandes, e boa acurácia na detecção da adenomiose quando comparada com a ressonância de alto campo.OBJECTIVE: To compare low-field (0.2 T with high-field (1.5 T magnetic resonance imaging in the assessment of pelvic endometriosis and adenomyosis. MATERIALS AND METHODS: Twenty-seven female patients with clinically suspected endometriosis were prospectively evaluated by means of high-field and low-field magnetic resonance imaging. The reading of the images was performed by a single radiologist, initiating by the low-field, followed by the high-field images. High-field magnetic resonance imaging was utilized as the golden-standard. RESULTS: Among the 27 patients included in the present study, 18 (66.7% had some type of lesion suggesting the presence of endometriosis demonstrated at high-field images. In 14 of these patients the diagnosis was correctly established by low-field magnetic resonance imaging. Endometriomas, tubal lesions, and endometriotic foci > 7 mm identified at the high-field images were also identified at low-field images with 100% accuracy, sensitivity and specificity. Among the nine patients diagnosed with adenomyosis by high-field images, eight were correctly diagnosed by low-field images with 88.9% accuracy, specificity and sensitivity. CONCLUSION: Low-field magnetic resonance imaging demonstrated a low sensitivity in the detection of small endometriotic foci, high sensitivity in the detection of endometriomas and large endometriotic foci, and high accuracy in the detection of adenomyosis when compared with high-field magnetic resonance imaging.

  18. Solenoid-free toroidal plasma start-up concept utilizing only the outer poloidal field coils

    Full text: Eventual elimination of in-board ohmic heating solenoid is required for the spherical torus (ST) reactors and it is considered to be highly desirable for advanced tokamak reactors. A fundamental challenge for using only the outer poloidal field coils for the start-up purpose is the difficulty of creating a sufficiently high quality field null region while retaining significant poloidal flux needed for subsequent current ramp up. Here, we show through both static and dynamic calculations that a carefully chosen proper set of outer poloidal field coils can indeed offer a promising prospect of creating a good quality 'multi-pole' field null while retaining sufficient poloidal flux, in particular, satisfying the 'Lloyd' criteria for the inductive plasma start-up. For a single turn TF system envisioned for ST-based CTF and power plant, the poloidal magnetic flux stored in the TF inner leg can provide additional significant flux. This concept can be readily extended to future devices for a multi-MA level start-up current due to the relatively simple physics principles and a favorable scaling with device size and toroidal magnetic field. (author)

  19. 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.

  20. 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.