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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

    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

    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.

  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

    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.

  17. 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.

  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. 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.

  3. 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...

  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. 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.

  3. 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

  4. 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.

  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. 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.

  18. 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...

  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. 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...

  12. 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.

  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. 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.

  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. 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

  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., 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.

  1. 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

  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. 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.)

  19. 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.

  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

    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.

  6. 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

  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 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.

  10. 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.

  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. 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.

  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. 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.

  18. 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

  19. 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...

  20. 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.

  1. 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

  2. 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

  3. 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

  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. 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.

  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 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.

  8. 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.

  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. 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

  11. 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.)

  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. 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.

  1. The Compact Muon Solenoid Detector Control System

    CERN. Geneva

    2012-01-01

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

  2. 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. 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.

  4. 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)

  5. 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)

  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. 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

  17. 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.)

  18. 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.)

  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. 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.

  8. 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

  9. 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.

  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. 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..

  12. 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.

  13. 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

  14. 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.

  15. 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)

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  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. 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

  14. 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 ...

  15. 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.

  16. 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)

  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. 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.)

  2. 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)

  3. 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...

  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

    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.)

  10. 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.)

  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. 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

  14. 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).

  15. 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.

  16. 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

  17. 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…

  18. 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.

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

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

    2015-06-15

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

  20. 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. 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)

  2. 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).

  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

    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

    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.

  9. 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

  10. 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.)

  11. 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

  12. 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.

  13. 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

  14. 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.)

  15. 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.)

  16. 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.)

  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. 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

  20. 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)

  1. 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.

  2. 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)

  3. 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

  4. 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.

  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. 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.)

  10. 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.